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Title: Cotton Weaving and Designing - 6th Edition
Author: Taylor, John T.
Language: English
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This e-text is based on ‘Cotton Weaving and Designing,’ from 1909.
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COTTON WEAVING AND DESIGNING
=THE ELEMENTS OF COTTON SPINNING.= By JOHN MORRIS and F. WILKINSON.
With a Preface by Sir B. A. DOBSON, C.E., M.I.M.E. With 169
Diagrams and Illustrations. Crown 8vo. 7_s._ 6_d._
=COTTON SPINNING CALCULATIONS AND YARN COSTS:= A Practical and
Comprehensive Manual of Calculations, Yarn Costs and other Data
involved in adapting the Machinery in all Sections, and for all
Grades of Spinning and Doubling. By JAMES WINTERBOTTOM, Lecturer in
Cotton Spinning, Municipal School of Technology, Manchester. With
Diagrams and other Illustrations. 8vo. 7_s._ 6_d._ net.
=JACQUARD WEAVING AND DESIGNING.= By F. T. BELL, Medallist in
Honours and Certificated Teacher in Linen Manufacturing and in
Weaving and Pattern Designing, City and Guilds of London Institute.
With 199 Diagrams. 8vo. 12_s._ net.
=PRINCIPLES OF WORSTED SPINNING.= By HOWARD PRIESTMAN. With 118
Illustrations. 8vo. 7_s._ 6_d._ net.
=PRINCIPLES OF WOOLLEN SPINNING.= By HOWARD PRIESTMAN. With 111
Diagrams. 8vo. 9_s._ net.
LONGMANS, GREEN, AND CO.
LONDON, NEW YORK, BOMBAY, AND CALCUTTA
COTTON WEAVING
AND
DESIGNING
BY
JOHN T. TAYLOR
LATE LECTURER ON COTTON WEAVING AND DESIGNING IN THE PRESTON,
ASHTON-UNDER-LYNE, CHORLEY, AND TODMORDEN TECHNICAL SCHOOLS AND ON
SILK WEAVING AND DESIGNING IN THE MACCLESFIELD TECHNICAL SCHOOL
AUTHOR OF DESIGNS FOR COTTON FABRICS, ETC., IN ‘THE TEXTILE
MANUFACTURER’
_REVISED UNDER THE DIRECTION_
OF
F. WILKINSON
DIRECTOR OF THE TEXTILE AND ENGINEERING SCHOOL, BOLTON
AND
H. NISBET
WEAVING MASTER OF THE TEXTILE SCHOOL, BOLTON
_SIXTH EDITION_
=WITH NUMEROUS DIAGRAMS=
LONGMANS, GREEN, AND CO.
39 PATERNOSTER ROW, LONDON
NEW YORK, BOMBAY, AND CALCUTTA
1909
_All rights reserved_
REVISER’S PREFACE
TO FIFTH EDITION
Taylor’s “Cotton Weaving” has for many years enjoyed a reputation among
Students who have attended Day and Evening Classes in Textile Weaving
and Designing.
It has, however, been found wanting in some important features, and
others have needed expansion so as to bring the work up to modern
requirements.
A further Edition having been called for, has afforded the opportunity
of having these deficiencies remedied by the addition of matters which
will put the book in line with the latest improvements in this section
of the Mechanical Arts. Chapter I., on preparatory processes, has been
entirely rewritten and enlarged. My obligations are many to Mr. H.
Nisbet, Weaving and Designing Master here, who has kindly carried out
this work. Some chapters have had new and important features added,
and many drawings are included for the first time, either as new
illustrations, or in place of others which had become obsolete. For
these drawings I am indebted to the same gentleman, who has made this
class of work a speciality.
Other chapters have been expanded, and partly rewritten. I should like
to say, in conclusion, that while the book was passing through the
press the assistance of Mr. Nisbet has been most helpful.
FRED. WILKINSON,
_Director_.
TEXTILE AND ENGINEERING SCHOOL,
BOLTON,
_February_, 1905.
PREFACE TO SIXTH EDITION
Another Edition having been called for has given opportunity for a
revision of the work in several directions. The most notable addition
is that of Chapter IX., which is quite new and deals with Automatic
Weft-replenishing Devices. It is hoped this will be of considerable
help in giving weaving students clear ideas on a phase of the subject
which is growing rapidly, and will tend to still greater importance
as increased production becomes more necessary. Quite a number of new
illustrations have been substituted for old ones.
FRED. WILKINSON,
_Director_.
TEXTILE AND ENGINEERING SCHOOL,
BOLTON,
_November_, 1909.
CONTENTS
CHAPTER PAGE
I. PREPARATORY PROCESSES 1
II. HAND AND POWER LOOMS 48
III. DROP AND CIRCULAR BOX LOOMS 107
IV. DOBBIES 123
V. MISCELLANEOUS 132
VI. JACQUARD WEAVING 137
VII. LENO WEAVING 173
VIII. TERRY LOOMS--CARD CUTTING--LAPPETS 187
IX. AUTOMATIC WEFT--REPLENISHING DEVICES 198
X. THE PRINCIPLES OF DESIGNING 218
XI. FIGURED DESIGN 278
XII. TEXTILE CALCULATIONS 307
INDEX 347
COTTON WEAVING AND DESIGNING
CHAPTER I
_PREPARATORY PROCESSES_
Yarn intended for manufacture into cloth requires to pass through
various stages of preparation, the character of which depends upon the
class of fabrics to be produced. Thus, some systems of treatment are
better adapted for the preparation of yarn for grey cloths (_i.e._ of
the native colour of cotton), some for mono-coloured, and others for
multi-coloured, fabrics. The choice of a system is often arbitrary, and
can only be made from a knowledge of local or special requirements.
The operations involved in the preparation of warps for most fabrics
are comprised under not less than five chief divisions, namely--
1. Winding yarn from any of its earlier stages on to warpers’ bobbins.
2. Warping.
3. Sizing.
4. Beaming, or winding yarn on to a weaver’s beam.
5. Looming, _i.e._ either drawing-in or twisting-in.
Each of these operations may be performed by a variety of machines of
distinctly different types that have been specially devised to meet
specific requirements, and which are, therefore, better adapted than
others for their special purpose. Before introducing the reader to the
details of the various types of machines in each division, it will
be better to briefly enumerate the different systems of preparation
usually adopted in the manufacture of the three classes of goods named
above.
PREPARATION OF GREY WARPS.
Grey warps are prepared by one or other of two systems, namely, (1)
Beam warping, for slasher or tape sizing; and, (2) ball or mill
warping, for ball or warp sizing; but by far the greater number are
prepared by the first-named system.
1. _Beam Warping and Slasher Sizing._
This system comprises the following operations, namely--
1. Winding yarn from cops, ring, or throstle bobbins on to warpers’
bobbins, by means of a “spindle” or “cop” winding machine.
2. Beam warping, whereby yarn is transferred, in the form of a wide
sheet, from warpers’ bobbins on to a large flanged beam.
3. Slasher or tape sizing, whereby yarn is withdrawn from several
beams, termed “back” or “slashers’” beams, to be sized, and
subsequently re-wound by the same machine on to a weaver’s beam by
simultaneous operations.
4. Looming, by which the threads of a new warp are placed in a loom
ready for weaving.
2. _Ball Warping and Sizing._
This system comprises the following operations, namely--
1. Winding yarn from cops or ring bobbins on to warpers’ bobbins.
2. Ball warping, in which a number of threads are withdrawn from
warpers’ bobbins and condensed into the form of a rope of untwisted
strands. This operation may be accomplished by several types of
machines. The one usually employed is the old-fashioned warping mill,
which coils warp-ends on to a large revolving reel or swift, from which
they are subsequently withdrawn and formed into a large ball. Ball
warps are also sometimes formed direct from warpers’ bobbins; also
sometimes from sections formed by a sectional warper; and sometimes by
means of a linking or chaining machine.
3. Ball-warp sizing.
4. Beaming, or winding a warp in an even sheet of threads on to a
weaver’s beam for the loom.
5. Twisting-in or else drawing-in warp-ends in the loom.
If the threads of a new warp are similar in number and counts to those
of the finished warp, and are to pass through the shedding harness
and reed also in a similar manner, it is more economical to twist the
threads of a new warp separately to the corresponding threads of the
old warp, and then draw the twisted portion of the warp bodily forward
through the healds and reed. If, however, the number of threads and
counts are greatly dissimilar, or if a different drafting is required,
then recourse must be had to drawing new warp-ends through the harness
and reed.
_Preparation of Mono-coloured Warps._
Warps of one colour may be prepared from either (1) warp-dyed and sized
yarn, or (2) from hank-dyed and sized yarn.
1. (_a_) _Warp-dyeing and Sizing._
The series of operations in this system are identical with those
involved in the preparation of grey warps by means of ball warping,
but with the additional process of dyeing immediately following the
operation of warping, and are as follows:--
1. Winding yarn on to warpers’ bobbins.
2. Mill or other system of ball warping.
3. Warp-dyeing and sizing.
4. Winding yarn on to a weaver’s beam.
5. Twisting-in or drawing-in.
1. (_b_) _Warp-dyeing and Sizing._
A system by which warps of one colour may be prepared by means of
sectional warping, from ball-dyed and sized yarn, has been recently
introduced. It comprises the following operations, namely--
1. Winding yarn from cops or ring bobbins on to warpers’ bobbins.
2. Mill or other system of ball warping.
3. Warp-dyeing and sizing.
4. Winding yarn from ball warps on to warpers’ bobbins by means of a
warp-winding machine.
5. Sectional warping and beaming.
6. Drawing-in or twisting-in.
2. _Hank-dyeing and Sizing._
This system involves the following operations, namely--
1. Reeling yarn from cops or ring bobbins into single or multiple
hanks. (A standard hank contains 840 yards.)
2. Hank-dyeing and sizing.
3. Winding yarn from hanks on to warpers’ bobbins by means of a
drum-winding machine.
4. Beam warping.
5. Beaming, or winding yarn from back beams on to a weaver’s beam.
6. Drawing-in or twisting-in.
Sectional warping may be substituted in lieu of beam warping.
_Preparation of Multi-coloured Warps._
Striped warps are usually prepared by one or other of two systems,
namely, (1) Yorkshire dressing, from warp-dyed and sized yarn; and (2)
sectional warping, from hank-dyed and sized yarn. Warp-dyeing yields
a more uniform tone of colour than hank-dyeing, for which reason some
manufacturers prefer to adopt the former system, although the latter
system is less costly.
1. _Yorkshire Dressing._
This system comprises the following operations, namely--
1. Winding yarn on to warpers’ bobbins.
2. Mill or other system of ball warping.
3. Warp-dyeing and sizing.
4. Yorkshire dressing, by which the required number of threads of each
colour are split off reserve ball warps. The warp-ends thus split off
are subsequently passed, in groups of two to four, through the dents
of a reed in proper order, according to the required warp pattern, and
wound on to a weaver’s beam.
5. Drawing-in or twisting-in.
2. _Sectional Warping._
This system comprises the following operations, namely--
1. Reeling yarn into hanks.
2. Hank-dyeing and sizing.
3. Winding on to warpers’ bobbins by a drum-winding machine.
4. Sectional warping, by which a warp is wound in sections upon wooden
or compressed paper blocks, with warp-ends in the same relative
position that they are required to occupy in cloth. Each section
forms a complete unit of the full warp, and when the required number
of units are prepared, they are placed together side by side, and
compressed upon a mandril; then the yarn is unwound from all sections
simultaneously, and wound on to a weaver’s beam.
5. Twisting-in or drawing-in.
_Preparation of Weft Yarn._
If weft yarn is to be woven in a grey state, it is rarely that it
requires to undergo any operation after it leaves the spinner. Grey
cops and ring bobbins of weft are usually placed in a shuttle and
woven direct; but if they are too large for a shuttle, their yarn is
transferred on to wooden or paper bobbins by means of pirn winding.
Cops intended for use as weft are frequently dyed and bleached in that
form, and woven without any operation of winding. If, however, weft
yarn is dyed or bleached in hanks, it requires to be subsequently wound
on to pirn bobbins or paper tubes to fit on a shuttle tongue. Weft is
also sometimes woven in a damp condition, with a view to inserting a
greater number of picks per inch in cloth than is possible with dry
weft.
_Winding Machines for Warp Yarn._
Fig. 1 is a diagram showing parts of a “spindle” or “cop” winding
machine, which is chiefly employed to wind grey yarn from cops, G,
or ring bobbins on to warpers’ bobbins, E. It is also sometimes
incidentally employed to wind coloured yarn from hanks, O (as
represented on the left-hand side of the diagram), when the amount of
work required of that kind would not justify the purchase of a “drum”
winding machine, which latter is better adapted for that purpose, for
reasons that will be explained later.
[Illustration: FIG. 1.]
As usually made, a “cop” winding machine contains a tin driving drum,
B, passing centrally down the machine, and carrying the driving pulleys
at one end of the tin drum shaft A. By means of cotton bands, C, the
tin drum drives four rows of spindles, D, arranged in two zigzag rows,
one on each side of the machine, as shown in part plan (detached).
Warpers’ bobbins, E, fit loosely upon the spindles, and rest upon
metal discs, F, secured to the spindle-shanks, by which bobbins are
frictionally rotated. During winding, yarn passes from cops, G, or
other source, over a drag-board, H, through a brush, I, and clearer
guide, J, thence over a glass rod, K, surmounted on guide-rails, and
on to warpers’ bobbins, E. The drag-board H is covered with flannel to
impart frictional resistance to yarn, and thereby prevent its passing
too freely and making soft bobbins. The clearer guide (of which a front
view is shown, detached) is a thin metal plate containing a number of
vertical slits, L, from near the top of which are two short slits, M,
branching upwards at an angle of about 45°. The vertical slits serve
to guide threads to their respective bobbins, and also to remove any
irregularities, as “slubbings” (_i.e._ thick, soft places consisting
of a mass of untwisted fibres). The short slits are intended to
prevent operatives from raising threads out of the guides, and so save
themselves the trouble and loss of time involved in piecing up broken
threads.
Spindle-shanks, D, are furnished with tightly-fitting grooved pulleys,
N, termed “wharves,” around which driving bands pass. Wharves on each
back row of spindles are usually made one-quarter of an inch larger in
diameter than those of front spindles, to cause them to revolve at a
slower velocity. The object of this is to enable some compensation to
be made for the constantly accelerating pace at which yarn is wound, in
consequence of the gradually increasing girth of bobbins by additional
layers of yarn. When bobbins become about half full on front spindles,
a winder removes them to back spindles to be filled.
If bobbins were allowed to fill on front spindles, the velocity at
which yarn would travel towards the completion of winding would impart
an abnormal degree of tension to it, and thereby make it more liable
to break. It is in consequence of the excessive degree of friction
to which yarn is subjected in a cop-winding machine that renders it
unsuitable for winding yarn that has been previously dyed and sized.
[Illustration: FIG. 2.]
One of the most important parts of a cop-winding machine is the
traverse motion to guide yarn between the flanges of a bobbin during
winding. These are constructed in great variety, but all belong to
one of two distinct types, namely, those governed by cams, and those
governed by what is termed a “mangle-wheel.” They are also constructed
to guide yarn at either a uniform or variable pace between the bobbin
flanges. If the traverse of yarn is uniform, bobbins will be wound
with a uniform diameter; but if a barrel-shaped bobbin is required,
the movement of guide-rails must be differential--quicker towards
the extremities, and slower towards the centre of their traverse,
with the object of placing a greater quantity of yarn upon them.
Traverse motions are usually designed on the compensating principle,
so that guide-rails on either side move in opposite directions at the
same time, and a falling rail helps a rising one to ascend, thereby
requiring less motive power to drive a machine.
[Illustration: FIG. 3.]
One of several modifications of a heart-cam traverse motion is shown in
Fig. 2. In this motion two heart-cams, Q, are set in opposite direction
upon a shaft, P, which is driven by a pinion, R, on the tin drum shaft,
A, and a train of wheels, S, T, U, V. The cams operate treadles, W,
whereby they fall and rise alternately. The free end of each treadle
farthest from its fulcrum is connected by means of straps or chains,
X, to pulleys; Y, secured to shafts; Z, extending one on each side of
the machine, and carrying several pinion wheels, 1, at intervals. The
latter engage with teeth in vertical racks, 2, which serve as supports
to guide-rails, 3. Thus, as treadles are depressed, guide-rails
are raised in a positive manner; but their return is effected by
gravitation. The character of movement imparted to guide-rails depends
upon the conformation of the cams, which may be constructed to give
either a uniform or differential traverse to guide-rails, as desired.
Another modification of a heart-cam motion is illustrated in Fig. 3. In
this motion a single cam, H, serves to operate both guide-rails, B, by
acting upon two treadle bowls, one of which, K, is placed above, and
the other, L, below the cam. Treadle bowl K is carried at one end of a
lever fulcrumed at O, whilst the other end, M, is connected to a lever,
Q. Through the medium of chains and chain pulleys, lever Q operates the
guide-rail on the left, whilst the lower treadle, T, operates that on
the right.
[Illustration: FIG. 4.]
A traverse motion constructed on the mangle-wheel principle, to wind
barrel-shaped bobbins, is represented in Fig. 4, A pinion, B, on the
tin drum shaft, A, drives wheel, C, which carries a small pinion, D.
Wheel C and pinion D are carried by a bracket that permits of a slight
concentric movement of those wheels to enable the pinion to engage
alternately on the outside and then on the inside of the mangle-wheel
E, with which it gears. On the same stud as the mangle-wheel is a
pinion, F, which engages with the teeth of a horizontal rack, G,
which is formed with a curved rack at each end. The curved racks
gear with eccentric wheels, H, fastened to shafts, I, which carry
chain pulleys, J, to wind up or let off the chains connected to the
supports of guide-rails. When pinion D revolves on the outside of
the mangle-wheel, the latter revolves until the gap K arrives at the
pinion, which immediately runs inside the mangle-wheel and reverses its
direction, until the gap L arrives at the pinion, which then runs on
the outside and again reverses the direction of the mangle-wheel. Thus,
rack G is slowly moved from one side to the other, and by acting upon
the eccentric wheels H at different distances from their axes, their
rotation is quicker or slower, according as the racks are in gear with
them at a point nearer to, or farther from, the centre of their shafts
respectively. On the same shafts as the eccentric wheels are a number
of chain pulleys on which are fastened chains, M, connected to the
supports, 2, of guide-rails, whereby the latter are raised and lowered
in a manner determined by the eccentric wheels.
[Illustration: FIG. 5.]
Another modification of a mangle-wheel motion is shown in Fig. 5. In
this motion a wheel, E, on the drum shaft, drives the larger wheel F.
The small pinion C turns the mangle-wheel H.
In order to obtain the _unequal_ motion of the rack R, to give the
barrel shape to the bobbin, a wheel, A, is fixed on the mangle-wheel
shaft a short distance from the centre of the wheel. Another wheel, B,
is fixed in a similar manner on another shaft, which also carries a
wheel which gears into the under side of the rack. The smaller side of
the wheel A gears into the larger side of the wheel B, as shown in the
diagram, and as the mangle-wheel shaft revolves, the larger part of A
will gradually come in contact with the smaller part of B, and this,
of course, will cause the rack to move quicker. When the smaller side
of A is in contact with the larger side of B, the guide-plate will be
guiding the yarn on to the middle of the bobbin; and when the larger
side of A is in contact with the smaller side of B, the guide-plate
will be putting the yarn on to either the top or bottom of the bobbin.
[Illustration: FIG. 6.]
The small side of the wheel A must be set in gear with the larger side
of the wheel B, and the traverse halfway of the bobbin. The pinion
C will at the same time be in contact with the middle pin in the
mangle-wheel, and the middle of the rack R driving the wheel M.
Fig. 6 is a part elevation, and Fig. 7 a plan, showing the essential
parts of a drum-winding machine to wind yarn from hanks, W, that
have been previously dyed and sized, on to warpers’ bobbins, C. In
this type of machine, warpers’ bobbins are held horizontally against
the peripheries of a series of revolving drums, B, fixed at regular
intervals upon a shaft, A, running centrally from end to end of the
machine. Bobbins are held in position by spindles, D, contained in
frames, E, which are fulcrumed at F to brackets, G, to permit of
bobbins rising as they increase in size. Since bobbins are driven
by surface contact with drums, the rate of winding is approximately
uniform throughout. Projecting from each bobbin frame is a latch, H,
to permit of a hook, I, holding a bobbin out of contact with its drum,
whilst an operative replaces a full bobbin with an empty one, or pieces
a broken thread.
[Illustration: FIG. 7.]
[Illustration: FIG. 8.]
[Illustration: FIG. 9.]
Yarn is guided between the flanges of bobbins at a uniform pace by
means of guides, J, carried upon guide-rails, K, supported in brackets,
L, and operated by a heart-cam, M. On the end of the driving shaft,
A, is a worm, N, which gears with a worm wheel, O, with which is
compounded a pinion, P, to drive wheel, Q, to which the cam M is
secured. As the cam revolves, it acts alternately upon two runners, R
and S, carried upon studs secured to the sliding base, T, of brackets,
L, whereby the latter receive a reciprocal motion, as indicated by
arrows, U and V.
_Winding Machines for Weft._
When weft yarn is in an unsuitable form to be placed within a shuttle
it is usually wound upon paper tubes, or wooden bobbins, by means of
one of the many systems of “pirn” winding. The chief parts of the
prevailing type of machine used for that purpose are represented in
Figs. 8, 9, and 10, which are end and front elevations and plan
respectively. Passing centrally down the machine is a tin drum, B,
on driving shaft, A, for the purpose of driving a number of wharves,
C, arranged at regular intervals on each side of the machine. Fixed
immediately above each wharve is a metal pirn cup, D, having a conical
interior, for the reception of a pirn bobbin, E. When in position, a
long spindle, F, having a heavy head-piece, G, passes through a bobbin
tube and enters a rectangular hole in the wharve immediately below. The
lower portion of a spindle which enters the wharve is also rectangular
in cross-section, and therefore revolves with its wharve. At the same
time, bobbins are driven by causing a projection, H, below spindle
heads to enter a slot in each bobbin head.
[Illustration: FIG. 10.]
Each thread passes from its source, over several stationary bars, to
impart the required degree of tension to it, thence over guide-rail, I,
by which it is guided up and down (as indicated by arrows, J) between
the extremities of a pirn cup, as it passes through an opening, K, in
the latter, and on to its bobbin. In consequence of yarn being built
upon a bobbin within a conical chamber, a bobbin, with its spindle,
rises automatically as it fills with yarn, and when filled it raises
its spindle clear of its wharve, and thus stops automatically.
[Illustration: FIG. 11.]
Guide-rails, I, are usually operated by means of a grooved cam, L,
fixed on a side shaft, M, which carries a worm wheel, N, driven from a
worm, O, on the end of a driving shaft, A. The cam acts upon a runner,
P, fixed on a sliding rail, Q, in which are formed vertical slots,
R, one on each side of the machine. Each vertical slot acts upon a
runner, S, secured to lever T, having shaft U for a fulcrum. At regular
intervals on shaft U brackets are fixed to support guide-rail I, which
rises and falls at a uniform pace in both directions.
In consequence of yarn rubbing against the stationary surface of a
pirn cup, it is liable to become burnished, and sometimes injured.
Many attempts have been made to overcome that objection by driving
bobbins by surface contact with revolving discs, and also by supporting
them against conical rollers. Fig. 11 shows one of several methods
of driving bobbins by means of bevelled discs, B, fixed at regular
intervals upon driving shafts, A, placed one on each side of the
machine. In this machine, as in an ordinary pirn cup machine, a bobbin,
C, rises automatically until filled, when its spindle, D, withdraws
from a hole in the bolster, E, and slides down a short incline, thereby
stopping a bobbin by carrying it from the disc.
WARPING.
The three methods of warping in use are mill warping, beam warping, and
sectional warping. The oldest form is mill warping, but this has been
largely superseded in almost all cases, except for coloured goods, by
the beam warping machine.
[Illustration: FIG. 12.]
[Illustration: FIG. 13.]
[Illustration: FIG. 14.]
In beam warping bobbins are placed in a creel. This is a frame
constructed to hold from 400 to 500 bobbins, and is the shape of
the letter ~V~, as this is the most convenient and easiest for
unwinding. The 400 to 500 threads, A, are taken through an expanding
reed, B (Figs. 12, 13, and 14). The ends are then passed over a tin
measuring roller, D, and under tension-rollers, 15 and 18, which
keep the yarn taut, and also pull it back when it is required to
turn backward to find a broken thread, or otherwise. Each thread is
then passed separately underneath a small bent wire drop-pin, 22.
Each thread bears the weight of one of these wires, and should the
thread break when the machine is in motion, the wire falls between two
rollers, 3 and 4, which latter is mounted so that a wire causes it
to move forward and, by releasing a “trigger” motion at Q, as it is
called, the machine is automatically stopped. This is the principle of
Singleton’s stop-motion, which is the one most commonly used. In front
of the stop-motion wires the yarn is passed through an expanding comb,
23, which regulates the width of the slashers’ or “back” beam, 26. This
beam is driven by friction; the beam rests on a drum, V, and as the
drum revolves, the beam is driven in such a manner that yarn is wound
at a uniform pace throughout, although the beam is gradually increasing
in diameter. One of these machines will supply about 80 to 90 looms
weaving medium counts of yarn. The creel is usually made to hold 504
bobbins, but any lesser number of ends may be put on a beam.
After leaving the warping machine the beams are taken to the slashing
frame, where a sufficient number of beams are put together to form the
warp for the loom.
=Mill warping.=--This system of warping is still in use for
warps used in the Bradford mixed goods trade, and for many classes of
coloured cotton goods in Lancashire, although slashed warps are fast
superseding the system for the former trade, and sectional warping is
replacing the system for the coloured trade. Mill warping is also in
general use in silk manufacture. Those spinners who supply warps to
Yorkshire worsted manufacturers have usually supplied them in the ball,
unsized. The warps are “mill” warped, and the manufacturer has them
sized to his own orders by cotton warp sizers, who usually combine this
business with dyeing and finishing in the Bradford district. Slashed
warps are now being used in the Bradford trade to a considerable
extent, the warps being in most cases slashed in Lancashire and sent on
beams.
[Illustration: FIG. 15.]
A warping mill consists of a large reel, Z (Figs. 15 and 16), of from
six to twenty yards circumference, which is made to revolve. This reel
is fixed upright in suitable framework, and the warper’s bobbins, W,
are placed in a creel, V, by the side of the reel. The ends are taken
from the bobbins, and drawn separately through the eyes of a row of
needles, T, which constitute what is termed a “heck.” This heck is so
constructed that one-half of the eyes can be raised above the other
half, to form a lease. The heck slides up and down the framework Y of
the mill, and thus forms a traverse and distributes the warp as the
reel revolves. At the commencement of a warp, the bunch of ends is
taken from the “heck” and fastened to a peg, 6, at the bottom of the
reel. As the reel revolves the heck slowly rises, and so causes the
warp to be wound on the reel spirally, without overlapping. The heck
is moved up and down a sufficient number of times to give the required
number of ends in the warp, when the warp is cut off and unwound, and
made up either in the form of a ball or a chain. The length of a warp
is determined by the number of revolutions made by the mill from the
commencement, until it is reversed at the other extremity.
[Illustration: FIG. 16.]
SECTIONAL WARPING.
Sectional warping is a system chiefly employed in the production of
coloured striped warps, from yarn previously dyed and sized in the
hank, and subsequently wound upon warpers’ bobbins by a drum-winding
machine. It is also sometimes employed in the production of grey
warps for ball sizing. As its name implies, the operation consists
of preparing a warp in sections, termed “cheeses,” each of which is
a complete unit, and virtually a transverse section, of the full
warp. When the required number of sections for a warp have been made,
they are compressed between flanges side by side upon a mandril of a
running-off machine, and their yarn run from them simultaneously on
to a weaver’s beam. Sometimes a sectional warper works in conjunction
with an automatic stop-motion similar to that of a beam warping
machine, in which case bobbins are contained in a ~V~-shaped
creel. They also sometimes work without a stop-motion. In that case
bobbins are contained in a curved creel similar to that employed in
conjunction with a warping mill, whereby the threads are better under
the observation of the operative warper, and broken threads may be more
readily detected. One of the most important considerations in sectional
warping is the production of sections of uniform diameter and length
of yarn; otherwise, warp-ends would be of varying degrees of tension;
also, waste of material would result from irregular lengths of yarn on
the sections.
[Illustration: FIG. 17.]
The principal parts of a well-known type of sectional warping machine
are shown in Figs. 17, 18, and 19. Warp-ends, A, are withdrawn from a
curved creel, and passed separately through needle eyes of a leasing
heck, B, thence through a ~V~-reed, D, over a tin measuring
roller, F, and on to a section block, O, which is compressed between
two flanges, N, O, upon a shaft, Q, by which it is turned. Flange N is
removable to permit of a full section being replaced by an empty one.
Another flange, 24, is keyed upon the section shaft, Q, and driven
by means of friction bowls, 20, 20’, placed one on each side, and
turned by driving shafts 16, 16′, each of which contains a wide loose
pulley, 17, 17′, a narrow fast pulley, 18, 18′, and a toothed wheel,
15, 15′, which are in gear. Thus, if driving strap 19 is placed in a
central position (as indicated) it runs on both loose pulleys, without
effect; but if placed upon the fast pulley 18, it will turn the section
_forward_, and wind yarn on the front, as shown, and if placed on fast
pulley 18′, it will turn a section _backward_, and wind yarn at the
back. This arrangement enables sections to be made with one-half of a
full repeat of a warp pattern, either alone or in addition to several
repeats (provided the pattern is a symmetrical one), so that when all
sections are placed in their proper position for running their yarn
on to a weaver’s beam, two halves of a pattern will join together
without a break. A uniform rate of winding yarn is maintained by
causing friction driving bowls, 20, 20′, to automatically recede from
the section shaft at a pace exactly corresponding to that at which a
section increases in diameter, thereby gradually retarding the velocity
of the section shaft.
[Illustration: FIG. 18.]
[Illustration: FIG. 19.]
A presser roller, 12, carried at the end of a lever, 9, 11, fulcrumed
on shaft 10, bears against yarn during winding, to wind it more
compactly, and also to ensure uniformity of diameter of sections
composing the same warp. During the winding of the first or “trial”
section, the presser, which is suitably weighted, is free to recede at
such pace as corresponds with the increasing diameter of that section;
but for subsequent sections, the presser is under mechanical control,
and may only recede at a prescribed pace, which should, however,
exactly coincide with its recession during the formation of the first
section. The movement of the presser is governed by means of a toothed
quadrant or sector, 1, communicating with presser lever, 9, by a
connecting rod, 6. The position of rod 6, in relation to the fulcrum
2 of the sector and the fulcrum 10 of the presser lever, determines
the velocity at which the presser recedes. A cam, P, on the end of
section shaft Q, imparts an intermittent rotary motion to a short
vertical shaft, Y, by means of lever S, U, and pawl W. Surmounting
shaft Y is a worm, Z, gearing with the teeth of sector 1 which slowly
rises as a section revolves, thereby causing the presser to recede, at
a prescribed pace. The number of revolutions of the section shaft is
indicated upon a dial; also, the length of yarn wound is indicated upon
a dial, by fingers operated by a train of wheels driven from worm G, on
the end of tin measuring roller shaft F. The two indicators, therefore,
serve as a check upon each other.
[Illustration: FIG. 20.]
[Illustration: FIG. 21.]
Section blocks are made in different widths from 3½ inches upwards.
Some are constructed so as to permit of expansion and contraction, as
shown in Fig. 20. Pressers are also constructed on a similar principle,
as shown in Fig. 21.
SIZING.
The chief systems of sizing are slashing, dressing, ball-sizing, and
hank-sizing.
The object of sizing is to strengthen the yarn by saturating it with
a starchy substance, which lays the fibres, thus making it weave with
less breakages. Other objects are to impart “feel” to the cloth, and
to give it additional weight. For light sizing, in which the object is
simply to strengthen the yarn, and not to increase its weight, only
10 to 15 per cent. is added to the weight. When 30 or 40 per cent. is
added it is termed medium sizing, and for heavy sizing often 100 per
cent. or more is added to the weight. The materials used for light
sizing are: wheat flour, sago, farina or potato starch, rice flour or
starch, maize.
Potato starch, or farina, is obtained from the tubers by reducing
them to a pulp and mixing well with water. The water carries away the
starch, and when allowed to stand the starch falls to the bottom of
the vessel and the water can be drawn away. Farina is much used in all
kinds of sizing, on account of its cheapness and the thickness of the
paste it produces when boiled with water.
Sago is much used in light sizing, for which it is specially adapted.
It is obtained from the pith of the sago palm, and made into flour by
treating with water and drying on hot plates.
Maize is a starch obtained from the Indian corn, and is sometimes used
for lightly sizing the finer counts of cotton yarns.
For light sizing it is not necessary to use anything but wheat
flour, farina, or sago, and a small quantity of softening material,
usually tallow or wax. Wheat flour is fermented before using by
mixing it well with water (about equal weights of each) and leaving
it for several weeks, occasionally stirring to keep the particles in
suspension. When flour is fermented new bodies are formed, which have
a powerful influence in preventing mildew. The fermenting cistern, 1
(Fig. 22), is usually a large vessel 8 feet by 4 feet by 4 feet, in
which are two revolving “dashers,” C, to stir the flour and water when
fermenting. Another similar cistern, 2, is used for storing called a
“storage and diluting” cistern, into which the mixture is pumped after
a few days, and left to further ferment. A force-pump, N, is used for
pumping from this to the mixing cistern, 3, where the softening and
weighting materials are added, after being boiled together in pan 4.
[Illustration: FIG. 22.]
Softening materials are used to render the yarn more pliable. The
articles mostly used for this purpose are tallow, wax, and soap,
cocoanut and palm oil.
The following mixtures are suitable for light sizing. They can be made
to give a greater or less percentage, according to the specific gravity
of the mixture. For testing the specific gravity or density of the
liquid, the Twaddell’s hydrometer is used. This instrument registers in
degrees the density of the mixture, or the amount of matter in solution.
For light sizing--
Wheat flour 280 lbs.
Tallow 16 „
Another mixture is--
Sago 100 lbs.
Farina 100 „
Tallow 10 „
Soap 4 „
For sizing with sago, cocoanut oil is often used as a softening
material. A mixture of these two gives as good a size as anything for
pure sizing.
Another mixture used for fine counts is--
Farina 100 lbs.
Wax 5 „
Tallow 4 „
1 gall. water to 1 lb. farina.
Almost every manufacturer uses different proportions of ingredients.
Many use wheat flour, farina, and sago mixed in various proportions,
whilst a flour and farina mixture in the proportions of 2: 1 is
considered by some to give the best results. Farina and sago are also
often mixed for light sizing in the proportion of two parts farina to
one part sago. Wheat flour carries through better than farina or sago,
and is therefore more generally used for the heavier kinds of sizing.
Any of these mixtures may be altered as regards strength, or otherwise,
by increasing or diminishing their density. If a mixture twaddles 10
degrees at a given temperature, it may be strengthened for heavier
cloths or higher picks by increasing the proportion of solid matter in
the mixture until it twaddles 15 degrees at the same temperature.
For adding weight to the cloth china clay is the chief ingredient used.
This material is found in deposits in Devonshire and Cornwall, and
is used in large quantities for the purpose of weighting and filling
cloth, more especially those manufactured for export to the Eastern
markets.
For what is termed “medium” sizing, viz. adding about 30 to 50 per
cent. to the weight of the cloth, the following materials are used in
various proportions, the proportion given being an example--
Flour 100 lbs.
Clay 30 to 40 lbs.
Tallow 15 lbs.
Chloride of magnesium 1 gallon.
Chloride of zinc ½ „
It will be noticed here that chloride of magnesium and chloride of zinc
are introduced along with the china clay. Chloride of magnesium is a
very powerful softener as well as a weighting material, and one of its
uses is to prevent the gritty feel which the addition of clay alone
would give to the cloth. It has a great affinity for water, and has
thus the power of attracting moisture to the cloth in which it is used.
It is this which really constitutes its softening effect.
Chloride of zinc is used to prevent mildew, which is a species of
vegetable growth which often occurs in sized cloth which has been left
damp, or which attracts moisture.
As chloride of magnesium attracts moisture, it is necessary to use an
antiseptic which will counteract the tendency of the cloth to mildew.
Chloride of zinc possesses valuable properties as an antiseptic, and
therefore it is often used where chloride of magnesium is used in the
size as a softening and weighting material.
If china clay is used for medium sizing without using chloride of
magnesium, it is necessary to greatly increase the proportion of tallow
or other softeners in the mixture. Thus, for every 100 lbs. of flour,
40 lbs. clay, and perhaps 25 lbs. tallow would be used.
Chloride of calcium has a similar effect to chloride of magnesium, but
is scarcely as powerful. It is used by many in light-sizing mixtures to
prevent the yarn becoming too brittle.
For heavy sizing the proportions of clay and mineral ingredients are
increased. In some classes of low shirtings, over 100 per cent. is
added to the weight of the yarn. The adhesive material mostly used
is wheat flour, as it carries the added materials better than farina
or sago; but farina is sometimes used for sizing up to 100 per cent.
Sometimes two parts clay to one of flour is used for very heavy
sizing. For 100 per cent. sizing about the following proportions may
be used:--
Flour 100 lbs.
Clay 130 „
Tallow 14 „
Chloride of magnesium 5 gallons
Chloride of zinc 2 „
Colouring matters are used in size to give the yarn any desired tinge.
Blue is the most common, as it neutralizes the yellowness of the
cloth given in heavy sizing. Only a very small quantity is required.
Sometimes yellow is used to give a brownish appearance to American
yarn, making it appear more like Egyptian. Numerous other materials are
used for various purposes in sizing. “Gloy” has been found useful for
strengthening warps for very heavily picked cloths.
Fig. 23 will show the principle of the slashing machine in its most
usual form. The warpers’ beams are placed in the creel 1, at the back
of the machine. In the diagram there are six beams, 1 to 6, so that
if each one contains 500 ends there would be 3000 ends in the warp.
The warp passes over roller A, and into the size-box. The small roller
B in the size-box is of copper, and is called the immersion roller.
The warp is passed under this, and its depth in the size mixture is
regulated by it. The warp then passes between two pairs of rollers, C,
D, and E, F (of which D and F are covered with flannel), to squeeze the
surplus size from the yarn. The size is kept boiling in the size-box
by the injection of steam. When the warp comes from the rollers E,
F, it passes over a large drying cylinder, M, and, after passing
almost completely round it, over a smaller cylinder, N, and then round
the fan P and over guide-roller Q. The warp then passes through the
dividing rods R (which divide the warp into the same portions that
come from each warpers’ beam), thence over guide-roller S and tin
measuring roller T, between drawing rollers U, V, and finally on to a
weaver’s beam, Z. This end of the machine is called the “headstock,”
and comprises the measuring mechanism, dividing rods, and winding-on
arrangement.
[Illustration: FIG. 23.]
The position of the immersion roller in the size has some effect upon
the amount of size retained on the warp, as by sinking the roller lower
in the box the yarn will remain longer in the size, and will therefore
absorb more. This roller is also mounted so that it can be lifted out
of the size altogether when the machine is stopped. The larger cylinder
is usually 6 feet to 7 feet diameter, and the smaller one about 4 feet
diameter, and both are heated with steam.
Some machines have a revolving brush between the size-box and the
cylinder. This brush is usually driven from the fan shaft, and its
object is to lay the projecting fibres, and so strengthen the yarn.
Brushes are only used in some fine-weaving districts, and not always
there. The brush gives the threads a round, smooth feel, and prevents
them sticking together. Under the brush which brushes the yarn a
smaller brush is placed, running at a slower speed than the one above
it; the lower brush is placed a short distance into the upper one, and
serves the purpose of cleaning it as it revolves.
The marking mechanism in the slashing frame usually consists of a
tin roller wheel, B (Fig. 24), driving the wheel D, called the “stud
wheel”; a screw or worm, E, on this stud drives the bell wheel F. The
marking hammer L is situated immediately above a vessel containing
colouring matter, and is lifted by a cam, P, driven from the tin
roller, and dropped suddenly on the warp, marking it to the required
lengths.
The length between each mark is regulated by the wheels used. The
tin roller wheel being the driver, if this is divided into the
product of the stud wheel and bell wheel, it will give the number of
revolutions of the tin roller for each mark, and this multiplied by
the circumference of the roller will give the length of the mark. The
formula will stand thus--
stud wheel × bell wheel × circumference of roller
------------------------------------------------- = length of mark.
tin roller wheel
[Illustration: FIG. 24.]
If the stud wheel contains 90 teeth, the bell wheel 45 teeth, the tin
roller wheel 60, and the roller is 14·4 inches circumference, the
length of the mark will be
90 × 45 × 14·4
-------------- = 972 inches
60
There are other marking motions in use for marking short lengths for
dhooties and scarves of various kinds, some being constructed so as to
mark scarves of two different lengths in succession--say one scarf is
marked 2 yards long, and the next one 4, the two being repeated.
[Illustration: FIG. 25.]
A “slow motion” arrangement is used for keeping the machine moving very
slowly whilst the weaver’s beam is changed. If the machine is stopped
completely, the warp becomes marked where it rests on the drying
cylinders. Fig. 25 shows the principle of this arrangement. There are
three pulleys, A, B, C, on the driving shaft D. Between the fast and
loose pulleys A, C, the slow motion pulley B is placed. When the belt
is moved from the fast pulley to the slow motion, the wheel F is set
in motion and drives another wheel, G, and this, through the bevel
wheels H, J, K, M, causes the catch O to drive the ratchet wheel P on
the driven cone shaft T. As the motion of the driving catch O is slower
than the cone T when driven by the fast pulley, the catch O will begin
to work when the strap is moved from the fast pulley to the slow motion
pulley, and the speed of the machine is reduced to the point where the
catch O overtakes the driven cone T.
Hot-air drying has been employed in place of cylinder drying, but
is not much used. In this system of drying the warp passes from the
size-box to hot-air chambers. The air is heated with steam pipes and
driven through the chambers by fans. Combinations of cylinder and
hot-air drying have also been used, but with little success.
In a slasher sizing machine, yarn is withdrawn from back beams and
finally wound upon a weaver’s beam at a uniform pace, notwithstanding
the gradually increasing diameter of the latter as it fills with yarn.
It follows, therefore, that the velocity of a beam must gradually
diminish from the commencement of winding. In order to meet such
requirement a beam is driven negatively by means of a frictional
driving motion, one of which is shown in sectional elevation in Fig.
26. This motion consists of a tooth wheel, A, whose sides are extended
beyond its proper teeth to form inner flanges, which latter are turned
at right angles to form an outer rim. Two outer flanges, B, interlock
with the rims of wheel A, as shown at C, so that wheel A and flanges
B always revolve at the same velocity. Enclosed within each chamber
between the inner flanges of A and outer flanges B is a sheet steel
disc, D, encased within two flannel washers, E, and secured to a hub
which rotates on a hollow beam shaft, O, in which is cut a channel
or key-bed, R. The hubs of steel discs D being furnished with a key
that enters the channel R, are free to slide upon shaft O, which they
rotate at the same velocity. The hub of wheel A revolves freely upon
the hubs of discs D; also, the hubs of flanges B revolve freely upon
shaft O; therefore, by compressing the flanges and discs together, any
degree of friction, within certain limits, may be induced. Pressure is
applied to the flanges by means of a vertical lever, F, fulcrumed at G,
and elbow lever J fulcrumed at K. A stud, I, in lever J bears against
lever F with a force that may be regulated by means of an adjustable
weight, L, N. On the inner end of shaft O, which receives one of the
beam gudgeons, is a disc, P, furnished with a stud or peg, Q, to which
is attached a rope or strap that encircles and grips one end of the
weaver’s beam, which is thereby turned. As a beam becomes filled and
its velocity diminishes, the slippage between discs D and the driving
flanges increases, because the velocity of the driving flanges remains
undiminished.
[Illustration: FIG. 26.]
_Automatic Supply of Size to a Sizing Machine._
There are numerous devices for the purpose of ensuring a continuous and
automatic supply of size to the size-box of a slasher sizing machine.
One of these is represented in Figs. 27 and 28. From the last mixing
beck 3 (Fig. 22) size is pumped into a storage beck, 5, whence it is
withdrawn and forced by a ram, N, along feed pipe Q, which is coiled
within a steam-heated chamber, U. From the steam chamber it returns
along pipe T, through regulating valve Z, and into the size-box, in a
boiling state. Within a separate chamber of the size-box is a floating
copper roller, X, connected at one end by means of rod Y to a tap which
regulates the flow of size through valve Z, on the principle of a ball
tap.
[Illustration: FIG. 27.]
[Illustration: FIG. 28.]
=Scotch dressing= is another system of applying size to the yarn.
This is a much slower method than slashing, and is chiefly suitable for
very fine yarns. In this machine the weaver’s beam is placed above an
expanding reed, R (Fig. 29), and to prevent the ends being crowded the
warper’s beams are divided, one-half the ends being placed at each end
of the machine. The warp is passed through a pair of rollers, A E, the
top one being very heavy. The lower roller of the pair is immersed some
distance in the size, and takes the size up to the yarn. After emerging
from the rollers or “squeezers,” the yarn passes through a revolving
brush, B, and over a fan in a hot-air chamber, F, then through another
brush, C, round a guide-roller through the expanding reed to the
weaver’s beam. The opposite half of the machine is a duplicate of this.
By this process the yarn is greatly strengthened. The brushing lays
down all the projecting fibres, and makes the thread round, preventing
any caking of the size on the threads. The production, of a machine of
this kind, is much less than that of a slashing frame, as only about
five beams a day can be dressed, whilst about fifteen beams could be
slashed in the same time. Instead of the circular brush B, sometimes
flat brushes are used. These are made to work on both sides, as shown
at Fig. 30. The dotted lines show the movement of the brushes. The warp
is brushed in the opposite direction to that in which it is moving.
[Illustration: FIG. 29.]
[Illustration: FIG. 30.]
[Illustration: FIG. 31.]
_Ball-warp Sizing._
Fig. 31 is a sectional elevation of a sizing machine for ball-warps.
One or more warps, A, are placed upon cones, and their yarn guided
over rollers, B, C, into a large size-box, 4, containing a series of
rollers, between which yarn passes until it emerges at guide-roller G,
when all excess of size is removed by rollers H, I. From the squeezing
rollers, yarn is conducted to a drying machine (Fig. 32), consisting
of a series of steam-heated cylinders arranged in two vertical zigzag
rows, O, N, the outer rows of which are driven from vertical shafts
containing a series of bevel wheels, Z, gearing with bevel wheels Y
at one end of the cylinder shafts. By this means yarn is subjected
to little tension, and its elasticity is better preserved. After
drying, the warps are deposited in box crates, R, to be subsequently
re-balled, ready for beaming or winding on to a weaver’s beam.
[Illustration: FIG. 32.]
[Illustration: FIG. 33.]
[Illustration: FIG. 34.]
_Beaming._
Beaming machines exist in great variety, but they may be classed under
the heads of (1) press beaming, and (2) tension beaming machines. An
example of the first-named type, as made by Butterworth and Dickinson,
Ltd., is illustrated in Fig. 33. If beaming is accomplished from back
beams prepared by a beam warping machine, a creel or stand capable
of holding several beams is situated in the rear of the headstock of
the beaming machine; but if beaming is from ball-warps, yarn from
the latter is passed in a circuitous manner under and over tension
and guide rollers A, B, for the purpose of tautening and separating
warp-ends, which are finally passed through the dents of an expending
comb, C, and on to a weaver’s beam. By causing weighted levers, D, to
bear upon the beam-ends during winding, a hard and compact beam is made.
A tension beaming machine of the type known as a Yorkshire dressing
machine, as made by Hattersley & Sons, is shown in Fig. 34. Yarn from
a warp, A, or from several sections of warps, is conducted under and
over the bars of a tension ladder, B, thence around dividing bars, C,
between tension rollers, D, and finally through a wraith or coarse reed
on to a weaver’s beam, E; but if Yorkshire dressing proper is adopted,
warp-ends are passed through the dents of a reed in groups of two to
four, and disposed according to pattern (if any) before passing on to a
weaver’s beam ready for weaving in the loom. By means of stepped speed
pulleys, F, G, the velocity of a beam may be retarded at intervals, to
compensate for the gradually increasing diameter of a beam, and thereby
maintain a uniform rate of winding.
CHAPTER II
_HAND AND POWER LOOMS_
[Illustration: FIG. 35.]
The three principal movements in weaving are shedding, picking, and
beating up the weft. By shedding is meant opening the warp threads
to allow the shuttle containing the weft to pass over certain ends
and under others. In the common hand loom the shed is made by the
weaver operating treadles with his feet. Fig. 35 shows the method of
connecting the shafts or staves with the treadles for weaving a plain
cloth. There are two treadles, A and B, placed underneath the loom,
and centred at C. The stave E is connected to the treadle A through
the lever G. The stave F is connected to the same treadle through the
“tumbler” T and the lever M. When the treadle A is pressed down it
will take the stave E down, and the stave F up. For the second pick,
the stave F is connected to the treadle B through the lever H, and the
stave E is connected to the same treadle through the “tumbler” R and
the lever N. Therefore, when the treadle B is pressed down, it will
take the stave F down and stave E up. By alternately pressing first one
treadle and then the other, we get each stave up for one pick and down
for the next, alternately, as required for weaving plain cloth. The
levers M and N are usually called “long lams,” the levers G, H “short
lams,” and the top levers R, T “tumblers.” The cords PP connect the
long lams and tumblers together at the side of the loom.
In mounting this loom for weaving a three-shaft twill, three treadles
are required, one treadle for each pick in the pattern. Supposing one
stave to be down and two up for each pick. The stave required to be
taken down for the first pick must be connected to the first treadle
through a short lam, and the two staves required to be taken up must
be connected to the same treadle through their long lams and tumblers.
Each pick in the pattern must be gone through in this manner. A
separate treadle is required for every pick in the pattern, unless the
same pick is repeated, in which case one treadle will do for more than
one pick. It is not advisable to break the regularity in the order of
treading in order to save a treadle; but in diaper patterns and similar
weaves the effect of a point draft is obtained by reversing the order
of treading.
[Illustration: FIG. 36.]
[Illustration: FIG. 37.]
Figs. 36 and 37 show the design and cording plan respectively for a
twill cloth requiring eight treadles.
[Illustration: FIG. 38.]
The hand loom is practically obsolete in the cotton trade, but it is
still extensively used in silk manufacture, where power looms, as at
present constructed, are not found advantageous for weaving the finer
classes of goods.
The chief shedding motions in power looms are tappets, dobbies, and
jacquards.
There are various kinds of tappets, the simplest and best for plain
or twill weaving being those shown at Figs. 38 and 39. The former is
the more general arrangement. In this the tappets are placed under the
loom, inside the framework. In the arrangement shown at Fig. 39 the
tappets are placed _outside_ the loom, and thus a larger amount of
floor space is taken up by the latter than the former.
Outside tappets are mostly used in the Yorkshire weaving districts, and
are commonly made for weaving with about eight shafts. The top levers,
with “half moons,” are centred at the cross rods EE (Fig. 39), and the
heald is lifted from both sides of the loom. The top levers are very
useful for equalizing the shed, as the connection with the upright rod
can be altered without difficulty.
[Illustration: FIG. 39.]
In a power loom there are two horizontal shafts, the top shaft A (Fig.
38) and the bottom shaft B. The former is used for working the slay,
by means of the crank C, and the connecting rod or “crank arm” D (Fig.
38). The bottom shaft is used for “picking,” and for this purpose it
is necessary that the shaft should revolve at one-half the speed of
the top or crank shaft. The toothed wheel on the bottom shaft must
therefore contain twice the number of teeth in the wheel on the crank
shaft which drives it. As a plain cloth contains two picks to the
round, and the bottom shaft makes one revolution for two picks, the
tappets are fixed to the bottom shaft. Each tappet acts upon treadle
bowl E, and therefore the size of the bowl will require to be taken
into consideration in shaping the tappets. For weaving plain cloth four
staves are usually taken, in order to prevent overcrowding the healds
on each stave, the ends being drawn through the staves in the order 1,
3, 2, 4. As the staves are fastened together in pairs, this is the same
as two staves.
The kind of movement to be given to the staves is very important,
especially in quick-running looms. The staves should be moving quickest
when they are level, and their speed should gradually decrease as the
shed opens. It is obvious that a movement of this kind will put as
little strain as possible on the warp, and therefore cause the fewest
breakages. The depth of the shed should only be sufficient to allow
the shuttle to pass, therefore the “lift” or stroke of the heald is
dependent upon the depth of the shuttle used. The shed when opened
should remain open only long enough to allow the shuttle to pass
through.
_Example._--What lift should a tappet have to make a plain cloth,
the other arrangements in the loom being as follows: Sweep of slay
5½ inches, distance of healds from cloth 8 inches, heald connected
to treadle 24 inches from fulcrum, distance from fulcrum to centre
of treadle bowl 16 inches, size of shuttle 1½ inch broad, 1¼ inch
deep?
Assuming that the tappets are under the loom, as in Fig. 38, the
treadle bowl E is 16 inches from M, and the heald connected 24
inches from M. If slay moves back from cloth 5½″, and the shuttle
is 1½″ broad and 1¼″ deep, it follows that the shed must be 1¼″
deep, or a little over, at a point 4″ from the cloth (5½-1½ = 4).
Then if the heald is 8″ from cloth, the stroke of heald may be
obtained--4: 8 ∷ 1¼: 2½″ stroke of heald, and as 24″ treadle: 16
∷ 2½: 1⅔ lift of tappet required.
To obtain the proper shape of the tappets for a plain cloth, the lift
or stroke of the tappets to give the required lift to the healds must
be obtained. If the lift of the heald is required to be 4 inches, and
the centre of the treadle bowl E (Fig. 38) is situated 12 inches from
the fulcrum of the treadle M, the heald being connected to the treadle
at, say, 18 inches from the fulcrum, the lift or stroke of the tappet
will be obtained as follows:--
As 18 : 12 ∷ 4
4
----
18) 48 ( 2⅔ lift of tappet
36
--
12
In some makes of looms the staves are connected to the treadles at
a point between the fulcrum and the treadle bowl, the fulcrum being
at the front of the loom. This necessitates a larger lift of tappet
than lift of heald. The tappets in this case are very large, and are
preferred by some manufacturers.
[Illustration: FIG. 40.]
=To construct a tappet for a plain cloth from the following
dimensions.=--Lift of tappet, 4 inches. Distance from centre of
shaft to nearest point of contact with treadle bowl, 2 inches; dwell
one-third of a pick. Diameter of treadle bowl, 2 inches.
At a radius of 2 inches describe the circle A (Fig. 40). This circle
represents the distance from the centre of the shaft to the nearest
point of contact with the treadle bowl.
At a radius of 3 inches describe the circle B. One inch added for
radius of treadle bowl.
At a radius of 7 inches describe the circle C. Four inches added for
lift.
The circle B represents the centre of the treadle bowl when the inner
circle of the tappet is acting upon the bowl.
The circle C represents the centre of the bowl when pressed down by the
tappet.
The pattern being a plain one, the circle must be divided into two
equal parts, and each half-circle will then represent one pick. By the
line DE divide the circle into two equal parts. Then, as the healds
must have a pause or dwell equal to one-third pick when at the top and
bottom of their stroke, divide each half-circle into three equal parts
by the lines FK, GH. Divide FH and GK each into six equal parts, and
divide the space between the circles B and C into the same number of
unequal parts, the largest being in the middle, gradually decreasing
towards the circles B and C.
From the corners of these unequal spaces, and with the radius of the
treadle bowl in the compasses, describe circles representing the
position of the treadle bowl at different parts of its movement.
Draw the curved line touching the extremities of the treadle bowl. This
gives the outline of the tappet.
As previously stated, the movement of the heald must be quickest when
the shed is nearly closed, and must gradually decrease in speed as the
shed opens. The unequal spaces into which the lift of the tappet was
divided give this eccentric movement to the heald. The curve of the
tappet will approach nearer to a radial line as the shed closes, and
the heald approaches the centre of its stroke. Referring to Fig. 40, it
will be seen that the treadle bowl is at rest from F to G and from H
to K, or one-third of a pick at both the top and bottom of the stroke.
Therefore the time allowed for change, or for moving the heald from
top to bottom, or _vice versâ_, is equal to two-thirds of a pick. If a
dwell equal to half a pick is required, it can be obtained by dividing
the pick into four equal parts and taking the middle two parts for
dwell. If two-thirds dwell is required, divide the pick into six parts
and take four parts for dwell.
It is usual to give the tappet which operates the back heald a slightly
larger lift than the tappet which operates the front heald. The
difference required can be easily calculated. In looms with the fulcrum
of the treadles at the front, and the healds connected to the treadles
between the fulcrum and the treadle bowls, some of the required extra
lift is obtained by connecting the back heald to the treadle at a
point further from the fulcrum than the front heald is connected. In
looms with the fulcrum of the treadles at the back of the loom, and
the tappets acting between the heald and the fulcrum, there will be a
greater difference between the size of tappets in proportion to the
lift than in the former case.
Tappets for twills, and other simple weaves, having more than two picks
to the round, are usually placed upon a counter-shaft, but outside
tappets are usually worked loose upon the bottom shaft.
The following example will illustrate the principle of constructing
twill tappets:--
Draw a tappet for a 3 up and 1 down twill. Distance from centre of
shaft to nearest point of contact with treadle bowl 3 inches, lift 3
inches, bowl 2 inches diameter, dwell ½ pick.
[Illustration: FIG. 41.]
At a radius of 3 inches describe the circle A (Fig. 41). At a radius of
4 inches describe the circle B (one inch added for treadle bowl). At a
radius of 7 inches describe the circle C (3 inches added for lift).
There being four picks in the pattern, divide the circles into four
equal parts by the lines DE, FG. Then each quarter-circle represents
one pick, and the tappets must be made to make one revolution for four
revolutions of the crank shaft. As the dwell of the heald (when the
shed is open) must be equal to half a pick, or half a revolution of the
crank shaft, divide the first pick into four equal parts by the points
O, L, M; make DP equal to DO, and FN equal to FM, and rule lines from
P, O, M, N to the centre. The distance OM represents the half-pick
dwell, and the distances OP and MN represent the half-pick which will
be allowed for changing the heald from bottom to top of its stroke, and
_vice versâ_. Divide OP and MN into six equal parts, and the lift of
tappet, or the distance between the circles B and C, into six unequal
parts, the largest in the middle and gradually decreasing towards
the two circles. From the corners of the unequal spaces describe the
small circles representing the treadle bowl at different parts of its
stroke, and draw the outline of the tappet touching the extremities of
these circles.
A tappet of this shape acting upon a treadle bowl two inches in
diameter will take the heald down for one pick and allow it to go up
for three picks. The heald will be held stationary for exactly half a
pick when at the bottom of its stroke, and will begin to rise slowly,
and gradually increase in speed as it approaches the centre of its
stroke, and will gradually decrease in speed as it approaches the top
of its stroke. The downward movement will be an exact counterpart of
this. In this kind of tappet it will be noticed that the heald, when it
gets to the top (if it is required up for more than one pick), remains
stationary until it is required to come down. Thus the heald remains at
the top while the circles revolve from N to P.
For this twill there will be four treadles, each treadle being operated
by a tappet of the same shape; but the tappet operating each succeeding
treadle will be placed one quarter of a revolution later than the
previous one.
The size of the treadle bowl has a very appreciable effect upon the
shape of the tappet, more especially when there are several picks to
the round. The movement imparted to the _centre_ of the treadle bowl
will be the exact movement given to the heald as far as regards dwell
and eccentricity, and as the tappet acts on the treadle bowl at a
distance of 1 or 2 inches from the centre, the required amount of dwell
and eccentricity must be given to the centre of the bowl, and the shape
of the tappet obtained accordingly. It will be noticed at Fig. 41, that
to give a dwell of half a pick to the centre of the treadle bowl, a
slightly longer dwell is on the tappet at the inner circle; and as the
size of the treadle bowl increases, this hollowing out of the tappet
must be increased in order to keep the dwell of the heald the same.
Fig. 42 is a drawing of a tappet for a 3 down, 1 up, 1 down, 1 up (six
to the round) twill. Centre of tappet shaft to nearest point of contact
with bowl 4 inches, lift of tappet 2 inches, bowl 1½ inch diameter,
dwell one-third of a pick.
[Illustration: FIG. 42.]
To construct this tappet:--At a radius of 4 inches describe the circle
A. At a radius of 4¾ inches describe the circle B. At a radius of 6¾
inches describe the circle C. As there are six picks to the round,
divide the circles into six equal parts by the lines D, E, F, G, H, I.
As there is one-third pick dwell, divide each pick into three equal
parts, and take the middle one for dwell. Rule the lines L, M, N, O, P,
Q, R, S to the centre, and divide the spaces allowed for change into
six equal parts, and the distance between the circles B and C into
six unequal parts, as in the previous examples. From the corners of
the unequal spaces describe the circles representing the movement of
the treadle bowl, and obtain the shape of the tappet accordingly. It
will be noticed that at point L the treadle bowl begins to dwell, and
remains stationary until it reaches the point S, when it begins to go
up. The heald will thus be down for the first, second, and third picks,
up for the fourth, down for the fifth, and up for the sixth.
[Illustration: FIG. 43.--Woodcroft’s Tappet.]
[Illustration: Fig. 44.
Woodcroft Section Tappet.--Sect. 1, riser (heald-up); sect. 2,
faller (heald-down); sect. 3, left-hand riser; sect. 4, neutral
riser; sect. 5, right-hand riser; sect. 6, left-hand faller; sect.
7, neutral faller; sect. 8, right-hand faller.]
=Woodcroft’s Section Tappets= are much used in weaving heavy
goods, such as velveteens and corduroys. They are made with various
numbers of sections to the round. A single tappet plate of one twelve
picks to the round is given at Fig. 43. Sections are sometimes made in
two kinds only. These are termed “risers” and “fallers,” according as
they raise or depress a heald respectively. Each heald requires one
plate and lever L, and as the tappets revolve, the lever L is moved up
and down. When the lever L is lifted, the heald is moved downwards.
A difference in the character of the shed produced by these tappets
as compared with ordinary tappets will be noticed. When the lever L
is lifted for two or more picks in succession, it comes down about
half-way each pick. This is unavoidable in section tappets consisting
only of “riser” and “faller” sections, which must join together
exactly wherever inserted, thereby causing all the healds to come
towards the centre of the shed after every pick. If there are twelve
sections to the round, any pattern repeating on three, four, six, or
twelve picks may be woven.
It is sometimes considered an objectionable feature of section tappets
(as represented in Fig. 43) that they cause all healds to be brought
level after every pick, thereby producing jerky shedding. This
objection, however, has been overcome by the construction of eight
distinct varieties of sections, as shown in Fig. 44, whereby healds
may remain either up or down for several picks in succession on the
“open-shed” principle, as with ordinary box-plate tappets cast in one
piece.
OSCILLATING TAPPETS.
Another form of shedding device, which embodies certain features of
ordinary rotary tappets and dobbies, is that known as the oscillating
or rocking tappet, an example of which is shown in Fig. 45. This type
of shedding motion consists of a series of plates, B, cast with upper
and lower projecting ridges, C, D, and fulcrumed on shaft A, upon which
they oscillate in a manner indicated by arrows, E. A movement in either
direction represents one pick. On each side of the rocking shaft A, and
oscillating with the tappets, is a pattern chain, F and F′, composed
of bowls and bushes threaded upon spindles, G. Pattern chains, which
represent odd and even picks respectively, are rotated alternately and
intermittently, one spindle for each pick, thereby causing elbow-levers
H to be raised or depressed, according to whether a bowl or a bush is
presented underneath them respectively. The vertical arms of H act upon
loose plates, I (termed “duck-bills”), which are fulcrumed upon short
studs, J. Grooves may thus be formed between either the upper or lower
ridges of tappet plates, and the upper or lower edges of “duck-bills,”
which grooves, by acting upon treadles K, governing healds, will
operate the latter in a manner determined by the pattern chains.
[Illustration: FIG. 45.]
Oscillating tappets are situated at one end of a loom, above the
crank shaft, from which they are driven by wheel gearing and suitable
connecting arms. They are chiefly employed on looms weaving fustians
and similar heavy and strong fabrics.
In plain looms with under tappets, the healds are generally connected
round a top roller or cone, so that when the tappet is pressing one
stave down, it is also taking the other stave up. The shedding is thus
positive. For weaving twills, satins, and such weaves, either spring,
roller, or pulley top motions are used. Where spring tops are used,
the tappet pulls the heald down, and the spring pulls it up again. Of
course, the speed at which the heald moves upward will be controlled by
the shape of the tappet exactly as it is in its downward stroke, but in
the up stroke of the heald, the tappet is only acting negatively. With
roller tops the movement is positive, as the rollers are so constructed
that as one stave is taken down by the tappets another is taken up. If
two staves are taken down, two will be taken up, and the tappets must
be constructed so as to allow this. It is very important also that the
tappets should be of the proper shape, and the exact counterpart of
each other, so that any one stave is allowed to go up at exactly the
same speed, and with the same amount of eccentricity in its movement,
as any other stave which is being taken down by the tappets. Fig. 46
shows the top roller arrangement for plain cloth. Straps are connected
to the staves over the rollers K, K^1; so that when one stave is taken
down by the tappet, the other is taken up.
[Illustration: FIG. 46.]
[Illustration: FIG. 47.]
For three staves the arrangement of rollers as shown at Fig. 47 is
used. The diameter of B must be twice that of A. Sometimes a pulley is
used at C, but when it is a roller, it is fitted into slots at the ends
so as to allow of its being lifted. The diameter of C is immaterial,
but the reason for B and A being as 2: 1 is that when the first heald
is taken down, either the second or third must be taken up the same
distance. Suppose the first stave is pulled down a distance of 4
inches, the strap E, being fastened to the roller A, which is half the
size of B, will be taken up only two inches; and as the tappets are
constructed so as to allow only one heald to go up each pick, if this
heald is the second one, the third being immovable, the second will be
taken up 4 inches, or the same distance that the first was taken down.
If the strap E were fastened to B, the stave would be taken up eight
inches instead of four. This arrangement of rollers is suitable for a 2
and 1 twill; either 2 down and 1 up, or 1 down and 2 up.
[Illustration: FIG. 48.]
[Illustration: FIG. 49.]
For four staves the arrangement shown at Fig. 48 is used. The relative
size of the rollers in this case is immaterial. If the first stave is
pulled down by the tappet 4 inches, and the second is the one allowed
to go up, it will be taken up the same distance. If the first is being
pulled down 4 inches, and the third is the one allowed to go up, the
fourth being immovable, the strap A is pulled down 2 inches, and B
lifted two inches, and the third stave will be lifted 4 inches. If any
one of the four healds is pulled down, another will be lifted the same
distance. This motion can be used for either a 3 and 1 twill or a 2 and
2 twill, or any four-stave pattern with the same number of staves going
up as are going down each pick. The arrangement shown at Fig. 49, in
which the top roller is dispensed with, is sometimes used for a 2 and 2
twill. It will not work a 3 and 1 pattern. The principle of this will
be understood by carefully following the movement of staves in weaving
a 2 and 2 twill. The draft used with Fig. 49 must be 1, 3, 2, 4, or the
first end must be drawn through the first stave, the second end through
the third stave, the third end through the second stave, and the fourth
through the fourth stave. If the pattern is the one shown at Fig. 50,
in which the first and second ends are down for the first pick, it is
obvious that to effect this the first and third staves will be down for
that pick, and the second and fourth staves will be up. For the second
pick the second and third ends are down, and as these are drawn through
the third and second staves respectively, these staves must be down for
the second pick. As the third is already down, it is only necessary to
take the second down, which will pull the first up as required. The
changes in this pattern will be easily understood from the following:--
1st pick: 1st and 3rd staves down, 2nd and 4th staves up.
2nd pick: 3rd and 2nd staves down, 5th and 3rd staves up.
3rd pick: 2nd and 4th staves down, 1st and 3rd staves up.
4th Pick: 4th and 1st staves down, 3rd and 2nd staves up.
[Illustration: FIG. 50.]
[Illustration: FIG. 51.]
Fig. 51 shows a top-roller device for five healds, with bottom heald
staves connected to treadles that are operated by tappets, J, fixed
upon a shaft underneath, but a little in front of the healds, and
driven by a train of wheels from a pinion, B, on the end of the crank
shaft A. This top-roller motion is designed for a five-end weave in
which either one heald only or else four healds, must be raised or
depressed for every pick, uniformly. Therefore, four of the five healds
must be suspended from one pair of rollers C, and one heald from
another pair of rollers D, with both pairs of rollers firmly secured
to the same shaft. Also, in order to obtain the proper leverage that
will ensure the four healds that are suspended from rollers C, exactly
counterbalancing the one heald suspended from rollers D, the diameters
of the pairs of rollers C and D must be in the ratio of one to four,
respectively.
All shedding motions of this type are based on the principle of
equilibrium, whether they are designed as top-roller motions, to
operate above the healds, or as stocks and bowls to operate below
the healds. Therefore, in all top-roller motions, the diameters of
the rollers on the same shaft must always be in inverse ratio to the
number of healds suspended from them. Likewise with stocks and bowls,
the leverage of the stocks must be in inverse ratio to the number
of healds to which the respective ends of the stocks or levers are
connected.
[Illustration: FIG. 52.]
An arrangement for seven staves is given at Fig. 52. The two pulleys
A and B, on the same centre, are in the ratio of 3: 4, and the pulley
D must be twice the diameter of C, the relative size of the remaining
pulleys being immaterial. If the first stave is pulled down, say, 6
inches, and the seventh stave is the one allowed to go up; then the
strap E will be pulled down 2 inches, and the strap F taken up 1½
inches, the strap G 3 inches, and the stave 6 inches, which is the same
distance that the other stave was pulled down. It will be the same with
any other healds in the set. If one stave is taken down, any other one
left loose by the tappet will be taken up the same distance. Instead of
the pulleys A and B, a lever may be used with its two arms in the ratio
of 3 to 4, the four staves being connected to the shorter arm, and the
three staves to the longer arm.
In some looms the positions of tappets and roller heald-motions are
inverted: tappets being fixed above, and roller motions below, healds.
In such cases the roller motions are known as “stocks and bowls,” which
terms, however, more correctly describe those devices consisting of a
combination of levers and bowls, or rollers, and not those consisting
of rollers upon shafts. In either case, they are based upon the same
principle of leverage, and act in an exactly similar manner to each
other. These devices are very limited in their scope, as regards
variety of weaves for which they are suitable, and may only be employed
for weaves of a regular character, in which the number of healds up
and down is the same for every pick. Of course, any number of healds
in a set may be up or down as required, but when once that number is
selected, and healds are tied up accordingly, it may not be changed
without re-tieing up.
[Illustration: FIG. 53.]
Fig. 53 shows a front and end elevation of what is known as the
Yorkshire shedding motion, in which tappets are cast upon a sleeve
slid upon one end of the second motion or picking shaft D, to operate
treadles, M, fulcrumed at N. Connecting rods, J, connect treadles,
M, with quadrant jacks, O, secured to cross-bars, K. These serve as
fulcra for the jacks, which are connected to upper heald staves, P, by
means of straps and cords, R, whilst bottom heald staves are attached
by cords to springs, S, for the purpose of pulling healds down, after
being raised by the tappets.
PICKING.
As soon as a warp-shed is sufficiently opened by the healds, the
shuttle, containing weft, is propelled through it. That operation is
termed “picking,” and may be accomplished by either of two types
of picking motions known as “over” and “under” picking motions. The
“over-pick,” also known as the “cone” and Blackburn pick (Fig. 54),
is in most general use, especially for narrow and quick-running looms
weaving light and medium-weight fabrics; whilst the “under-pick” (Figs.
56 and 57), of which there are many modifications, is chiefly confined
to medium and broad looms, which require a picking motion capable of
developing greater force. A shuttle is propelled by a picker made of
hide, which is connected by means of a leather strap to the picking
stick A (Fig. 54). The upright shaft B is the fulcrum of the lever.
The cone C is the short arm of the lever which receives the force from
the picking tappet D. The tappet is so shaped that as it revolves it
gives a sudden quick movement to the cone-shaped stud, and therefore to
the shuttle. It is obvious that as the shuttle must move from one side
of the loom to the other, and back again, for two revolutions of the
crank shaft, the picking tappets must be placed on a shaft whose speed
is one-half that of the crank shaft; therefore the bottom shaft in the
loom on this account is made to move at the required speed, and the
picking tappets are placed on this shaft at opposite sides of the loom.
[Illustration: FIG. 54.]
The chief requirement in a good pick is that as little force as
possible shall be wasted in the loom. The relative positions of the
tappet shaft and cone should be such that the force is exerted as
nearly as possible in the direction of the dotted line E at right
angles with the upright shaft B. It is impossible to effect this
throughout the whole course of the stroke, but it is obvious that if
this is approached as nearly as possible, the pick will be smooth, and
the wear and tear reduced to a minimum. A very considerable amount of
power is wasted if the direction of the force is too much downward.
The direction of the force is at right angles to a line drawn tangent
from the cone at the point of connection with the picking tappet. Thus
in Fig. 54 the direction of the force is indicated by the dotted line
M, which is at right angles to the dotted line N, drawn tangent to the
cone at the point of connection with the tappet.
[Illustration: FIG. 55.]
The intensity of the force depends on the length of the stroke of the
tappet and on the suddenness of the curve of the working face. If in
two looms the length of tappet is the same, but in one the portion of
a revolution occupied in making the stroke is less than in the other,
there will be a greater intensity of force in the loom with the quicker
stroke. In Fig. 55 the portion of a revolution occupied in making the
stroke is indicated by the angle AB. If this angle is increased, the
force of the pick will be lessened, and if the angle be decreased, the
force of the pick will be augmented. It will be understood from this
that if the picking tappets are short the pick is liable to be harsh.
If a fair length of tappet is given, a smoother and better-timed pick
can be made. The curve on the picking tappet gradually approaches
a radial line as it nears the end of the stroke, but the combined
influence of the change in the position of the cone and the backward
movement of the slay causes the shuttle to move quickest in the early
part of its movement in the box.
There is a relation between the length of the shuttle-box and the
length of the picking tappet. If the tappet is a short one, the
shuttle-box must be short; and if a longer tappet is used--the leverage
of the picking arm and other parts being the same--the shuttle-box will
be longer.
It is obviously inadvisable to have too short a tappet, as the movement
of the shuttle in the box must in that case be extremely sudden, in
order to have the necessary force.
[Illustration: FIG. 56.]
[Illustration: FIG. 57.]
An underpick motion is given at Fig. 56. A picking treadle, A, centred
at C, is pressed suddenly down by the picking bowl B, which is fastened
on to the wheel on the bottom shaft in the loom. A strap, E, connects
the treadle and the picking lever. In Fig. 57 this connection is shown.
The strap from the treadle is fastened to the quadrant, and as the
treadle is pressed suddenly down, the picking lever H is moved forward.
The shape of the curve E, which the picking bowl strikes, regulates
the character of the movement given to the lever H, and it is well
not to have the curve too small and sudden, or the pick will not be
satisfactory. The curve on the treadle in Fig. 88 (p. 120) is perhaps
better than the one in Fig. 56, as it is longer, and is therefore not
liable to be so jerky.
There are numerous other picking motions, which chiefly differ in the
mechanism for actuating the picking lever.
=Beating up the Weft= is the third primary movement in weaving.
This movement is performed by a crank on the top shaft in the loom and
a connecting rod or crank-arm which connects the crank and the slay
together. This is shown at Fig. 38, where the crank C and crank-arm
D give a reciprocating movement to the slay S. The slay moves upon a
rocking shaft, E, as a fulcrum, and when the crank is at the front
centre the slay-swords should be perpendicular, or nearly so. Sometimes
the fulcrum is taken a little forward, but it is never advisable to
have the slay over the perpendicular when in contact with the cloth.
The movement of the slay should be eccentric. It is obvious that
when the slay is at the back of its stroke its movement should be
sufficiently slow to allow time for the shuttle to pass through
the shed; and that when beating up, the speed of the slay should
be sufficient to knock the weft firmly into the cloth. A crank and
crank-arm give the kind of movement required.
The eccentricity of the slay’s movement depends upon the length of
the crank and crank-arm, and upon the position of the crank-shaft in
relation to the point of connection of the crank-arm with the slay. The
position of the crank-shaft in relation to the connecting pin varies in
different makes and widths of looms. We shall see that the position of
the shaft and the direction in which the loom runs have an important
bearing on the force exerted by the slay in beating up the weft. For
ordinary looms the usual position of the shaft is a little below the
level of the connecting pin when at the front centre, and when the
shaft is in this position the movement of the slay is the most even
and least eccentric. To obtain this position of the crank-shaft in a
diagram, first draw the line SA (Fig. 58) to represent the slay-sword
when the reed is in contact with the cloth; this we will assume is
perpendicular. We will suppose SA to be 24 inches, S being the rocking
shaft and A the connecting pin which connects the crank-arm with the
slay. Suppose the loom we are dealing with to have a 3-inch crank and a
12-inch crank-arm. Describe the arc AN from the centre S, and mark off
on the arc a distance from A equal to twice the length of the crank. As
the crank is 3 inches long, mark off the point B, 6 inches from A. This
point B represents the position of the connecting pin when the slay is
at the back of its stroke.
[Illustration: FIG. 58.]
From A, rule the line AX in such a position that the arc AB makes
the least possible departure from it. It will be found that this
necessitates AX cutting the arc AB at a point a little past the middle
of the arc. With the length of the crank and crank-arm, viz. 15 inches,
in the compasses, from A as the centre cut the line AX at E, and this
gives the position for the crank-shaft which will give the least
possible eccentricity to the slay. This will be obvious, as the nearer
the connecting pin moves on the straight line AX, the less will be the
eccentricity of the slay.
That the movement of the slay in the back half of its stroke is slower
than in the front half can easily be proved by taking the length of the
crank-arm in the compasses, and, after bisecting the arc AB at C, from
C marking off the points D and H on the crank circle. It will be seen
that both these points are somewhat inside the top and bottom centres
of the crank indicated by the dotted line, and therefore the slay moves
from C to A and back, the front half of its stroke, in less time than
it moves from C to B and back to C. The reason for this eccentricity or
unevenness in the movement of the slay is that when the crank is moving
from the back centre to the top centre the crank-arm is oscillating
and opening an angle with AX while the slay is moving forward, and
therefore while the crank is making this quarter of a revolution, the
connecting pin of the slay will move something less than from B to C;
and while the crank is moving from the top centre to the front centre,
the crank-arm is straightening or closing the angle while the slay
is moving forward, and thus the connecting pin will move a greater
distance than from C to A while the crank is making this quarter of a
revolution. When the crank moves from front to bottom centre the angle
is opening while the slay is moving backwards, and therefore the pin
will move a little more than from A to C; and when the crank moves
from bottom to back centre the angle is closing while the slay moves
backwards, thus retarding the velocity of the slay.
[Illustration: FIG. 59.]
This will be better understood from Fig. 59, where CD is the
crank-arm, and ED the crank at the top centre. A is the position of
the connecting pin when at the front of its stroke, and B its position
when at the back of its stroke. The dimensions are as in Fig. 58--viz.
12-inch arm, 3-inch crank--and for simplicity we will assume the
connecting pin moves on the straight line AE. From A to B is 6 inches,
and therefore it is obvious that AC is something over 3 inches, and
that the connecting pin moves this distance whilst the crank is making
the quarter of a revolution from top to front centre. The distance AC
can be obtained as follows. It is obvious that CDE is a right-handed
triangle, and therefore CD^2 is equal to CE^2 + ED^2. Therefore
CD^2-ED^2 = CE^2, and having obtained the length of CE, we can subtract
this from AE, which leaves the length of AC. The formula will stand
thus--
CD^2 - ED^2 = CE^2
12^2 - 3^2
144 - 9
∴ 135 = CE^2
and CE = √(135) or 11·6189
length of AE = 15·0000 inches
11·6189 inches
-------
AC = 3·3811 inches
The answer may be obtained in one calculation as follows:--
AE - √(CD^2 - ED^2) = AC
or 15 - √(12^2 - 3^2)
15 - √(144 - 9)
15 - √(135)
15 - 11·6189 = 3·3811
We thus see that the connecting pin moves 3 inches + 0·3811 inch while
the crank is moving from the top to front centre. It will also move the
same distance while the crank moves from front to bottom centre.
When the crank is moving from the bottom to the back centre, the
connecting pin will move 3 inches - 0·3811.
3·0000
0·3811
------
2·6189 inches,
and the same distance when the crank moves from back to top centre.
It is often necessary in comparing looms to obtain the distance
travelled by the connecting pin for a smaller movement of the crank
than a quarter of a revolution.
Suppose it is desired to find the distance travelled by the connecting
pin while the crank moves through 30 degrees to the front centre.
Take a 4-inch crank and 12-inch crank-arm. In Fig. 60, ED is the crank,
4 inches, and DC the crank-arm, 12 inches, the angle O = 30 degrees. P
is the position of the connecting pin when at front of its stroke.
[Illustration: FIG. 60.]
To find the distance CP. From a table of natural sines we can obtain
the sine of an angle of 30 degrees, viz, sin 30° = 0·5, and therefore,
knowing the length of ED, viz. 4 inches, we can obtain the length of
DN, it being 0·5, or half of ED, in an angle of 30 degrees.
Having two sides of a triangle, we can obtain the third side thus:
ED^2 - DN^2 = EN^2 and
CD^2 - DN^2 = CN^2
Having obtained the length of CN and EN, we can easily obtain CP by
subtracting CF from the length of crank and crank-arm together. Working
out the problem in figures we get--
ED^2 - DN^2 = EN^2
4^2 - 2^2 = EN^2
16 - 4 = EN^2
12 = EN^2
∴ EN = √(12) or 3·4641. And
CD^2 - DN^2 = CN^2
12^2 - 2^2 = CN^2
144 - 4 = CN^2
140 = CN^2
∴ CN = √(140) or 11·8321
and 11·8321 + 3·4641 = 15·2962
Therefore CE = 15·2962 inches, and subtracting this from PE, which is
16 inches (12 + 4 = 16), we get 16-15·2962 = 0·7038 as the distance CP,
which is the distance moved by the connecting pin for the 30 degrees
movement of the crank.
The complete formula is as follows:--
PE-[√[(ED^2-DN^2)] + √[(DC^2-DN^2)]] = CP, or distance moved by the
connecting pin for the given number of degrees through which the crank
moves, ND being obtained from a table of sines.
To find the distance moved by the connecting pin while the crank moves
through 5 degrees--say, from 30 degrees to 25 degrees in beating up.
To solve this it will only be necessary to subtract the length of CE
when the crank is forming an angle of 30 degrees from the length of CE
when the crank forms an angle of 25 degrees. In the previous example
we found that for 30 degrees, CE = 15·2962 inches, and therefore
proceeding in the same manner for 25 degrees, we get from table of
sines, sin 25° = 0·4226, and 0·4226 of 4 inches 1·69; therefore ND
=1·69 inches, and
4^2 - 1·69^2 = EN^2
16 - 2·856 = EN^2
13·144 = EN^2
∴ EN = √(13·144) or 3·626
and 12^2 - 1·69^2 = CN^2
∴ 144 - 2·856 = CN^2
141·144 = CN^2
∴ CN = √(141·144) = 11·88;
therefore CN = 11·88 inches, and CE will equal 11·88 + 2·626, or 15·506
inches, when the crank is forming an angle of 25 degrees.
15·506 length of CE for 25 degrees
15·296 length of CE for 30 degrees
------
inches 0·210 distance moved by pin whilst crank moves
through 5 degrees, from 30 degrees to 25
degrees, in beating up.
In this manner it is easy to calculate the distance travelled by the
pin for any number of degrees moved by the crank, and by comparing the
velocity of the slay in different looms, the force of the beat up can
be compared.
_The force exerted by the slay varies as the square of its velocity._
Thus, if in two looms where the _weight_ of the two slays and the
tension on the two warps are the same, the velocity of the slay in one
loom is twice that of the other at a certain point in the beat up, the
force of the former slay at that particular point will be four times
the force of the latter, 1^2: 2^2 ∷ 1: 4.
We can thus compare the force exerted by the slay in different looms at
any point of the beat up.
The force of the beat up is chiefly exerted upon the pick when the
crank is nearly at the front centre, and the force exerted will also
depend considerably upon the tension on the warp; but the slay is doing
some work in beating up from the moment the reed begins to move the
pick forward.
Possibly the most reliable method of comparing the force of the beat
up in different looms is to calculate the time occupied by the slay
in moving through a specified distance at the front of its stroke in
beating up. This necessitates a rather different calculation to the
preceding examples, but is equally as simple.
[Illustration: FIG. 61.]
Suppose it is required to compare the force exerted by the slay in
beating up (say the front 1 inch of its stroke) in two looms, one with
a 12-inch crank-arm and 3-inch crank and the other with an 11-inch arm
and 4-inch crank. The weight of the slays, the speed of the looms, the
tension on the warps, and the timing of the primary movements, the same
in each case.
In Fig. 61 the smaller circle represents the 3-inch crank and the
larger one the 4-inch crank. CP = 1-inch, CB = 11-inch arm, and CD =
the 12-inch arm. It is obvious that if we can obtain the two angles
made by the cranks, viz. ∠ CAB and ∠ CAD, we shall be able to get the
time, or fraction of a revolution, occupied in moving the slay from
C to P. As we know the three sides of the triangle we can obtain the
angle enclosed by any two sides, and what is required in this case is
to obtain the angles BAC and DAC. In triangles of this kind where there
is no right angle, we can obtain the cosine of the angle as follows:--
CA^2 + AD^2 - DC^2
------------------ = AQ, the cosine of angle DAC,
2CA.AD
and CA^2 + AB^2 - BC^2
------------------ = AN, the cosine of angle BAC.
2CA.AB
The proof of this formula is given in Euclid, Book 2.
Having obtained the cosines of the two angles, we can find the angles
themselves by referring to a table of sines and cosines.
Then as AP = 15 inches,
CA = 14, AD 3 inches, DC 12 inches, BA 4 inches, BC 11 inches; and
reducing the formulæ to figures, we get:
14^2 + 3^2 - 12^2 196 + 16 - 144
----------------- = -------------- = 0·7262 cosine,
2 × (14 × 3) 84
and by referring to a table of sines, we find that cosine 0·7262 =
angle 43° 26´, therefore angle DAC = 43½°, about. Also
14^2 + 4^2 - 11^2 196 + 16 - 121 91
----------------- = -------------- = --- = 0·8125,
2 × (14 × 3) 112 112
and by referring to a table of sines and cosines, we find cosine 0·8125
= angle 35⅔°.
We thus find that to move the connecting pin 1 inch to the front of
the stroke, in the loom with 11-inch arm, the 4-inch crank will move
through 35⅔°, and in the loom with the 12-inch arm the 3-inch crank
will move through 43½° for the same movement of the slay. Assuming
the force exerted by the latter to be 1, the force of the former will
be as 35⅔ squared: 43½ squared ∷ 1: _Ans._
It may be as well here to give a short explanation of the system of
obtaining angles by sines and cosines.
As the crank moves forward it is obvious that the line DQ will become
shorter, and as the angle becomes larger the line DQ will increase in
length. In trigonometry, the ratio between the length of the line DQ
and the radius AD is called the _sine_ of the angle, and if the radius
is 1, the length of DQ will be the value of the sine. In an angle of
30° the sine is exactly ½ the radius, and the relation between the
radius and the sine for every angle is known, and arranged in “tables
of sines.” The length of AQ will also vary with the angle, and the
length of this line is called the “cosine” of the angle QAD. The
_cosine_ of an angle of 30° is therefore the same as the _sine_ of an
angle of 60°. When the sine is known it is easy to obtain the cosine as
follows:--
Cosine = √(1-sin^2). Thus for an angle of 30°, cosine = √(1-0·5^2), or
cos^2 = 1-0·5^2, therefore cos^2 = 1-0·25, or cos^2 = 0·75, ∴ cos =
√0·75 = 0·866. By reversing, the sine may be obtained from the cosine.
The value given to the sines and cosines must not be taken for the
_actual_ length of the lines; they are simply the ratio to the radius.
Thus in an angle of 30°, if the radius is 1 inch the length of the sine
will be ½ inch and the cosine 0·866 inch. If the radius is 2 inches,
the actual length of the sine will be 1 inch and of the cosine 1·732
inches.
TABLE OF SINES AND COSINES.
+--------+--------+--------+------+
|=Angle.=| Sine. | Cosine.|Angle.|
+--------+--------+--------+------+
| =0°= |=0·00= |=1·00= | =90°=|
| 1° | ·0175 | ·9998 | 89° |
| 2° | ·0349 | ·9994 | 88° |
| 3° | ·0523 | ·9986 | 87° |
| 4° | ·0698 | ·9976 | 86° |
| =5°= | =·0872=| =·9962=| =85°=|
| 6° | ·1045 | ·9945 | 84° |
| 7° | ·1219 | ·9925 | 83° |
| 8° | ·1392 | ·9903 | 82° |
| 9° | ·1564 | ·9877 | 81° |
| =10°= | =·1736=| =·9848=| =80°=|
| 11° | ·1908 | ·9816 | 79° |
| 12° | ·2079 | ·9781 | 78° |
| 13° | ·2250 | ·9744 | 77° |
| 14° | ·2419 | ·9703 | 76° |
| =15°= | =·2588=| =·9659=| =75°=|
| 16° | ·2756 | ·9613 | 74° |
| 17° | ·2924 | ·9563 | 73° |
| 18° | ·3090 | ·9511 | 72° |
| 19° | ·3256 | ·9455 | 71° |
| =20°= | =·3420=| =·9397=| =70°=|
| 21° | ·3584 | ·9336 | 69° |
| 22° | ·3746 | ·9272 | 68° |
| 23° | ·3907 | ·9205 | 67° |
| 24° | ·4067 | ·9135 | 66° |
| =25°= | =·4226=| =·9063=| =65°=|
| 26° | ·4384 | ·8988 | 64° |
| 27° | ·4540 | ·8910 | 63° |
| 28° | ·4695 | ·8829 | 62° |
| 29° | ·4848 | ·8746 | 61° |
| =30°= | =·5000=| =·8660=| =60°=|
| 31° | ·5150 | ·8572 | 59° |
| 32° | ·5299 | ·8480 | 58° |
| 33° | ·5446 | ·8387 | 57° |
| 34° | ·5592 | ·8290 | 56° |
| =35°= | =·5736=| =·8192=| =55°=|
| 36° | ·5878 | ·8090 | 54° |
| 37° | ·6018 | ·7986 | 53° |
| 38° | ·6157 | ·7880 | 52° |
| 39° | ·6293 | ·7771 | 51° |
| =40°= | =·6428=| =·7660=| =50°=|
| 41° | ·6561 | ·7547 | 49° |
| 42° | ·6691 | ·7431 | 48° |
| 43° | ·6820 | ·7314 | 47° |
| 44° | ·6947 | ·7193 | 46° |
| =45°= | =·7071=| =·7071=| =45°=|
| Angle | Cosine | Sine | Angle|
+--------+--------+--------+------+
We see from Fig. 61 that in a loom with a 4-inch crank and 11-inch arm,
the velocity of the slay is much greater when beating up than with the
3-inch crank and 12-inch arm.
The effect of the length of the crank-arm on the velocity of the slay
can easily be shown by a diagram or by calculation. If the length of
the crank-arm be altered without altering the length of the crank,
there will be found a somewhat quicker movement of the slay at the
beat up in the loom with the shorter arm. The difference is not so
great when the crank-arm is a long one in proportion to the crank. The
chief cause of the difference in the velocity of C in Fig. 61 is the
difference in the length of the _crank_. It is obvious that the longer
the crank the greater the angle which it will cause the arm to make,
and therefore the greater will be the acceleration of the velocity of C
when the angle is closing and the slay moving forward. Likewise, it is
obvious that the shorter the arm the larger will be the angle to close,
but the _principal_ thing to notice is that an increase in the length
of the _crank_ causes an increase in the velocity of the slay _owing
to the extra distance which it has to travel in each revolution_; so
that even if the crank-arm were lengthened in exact proportion to the
increase in the length of the crank, so as to keep the angle to be
closed in beating up the same, there would still be a considerable
increase in the velocity of the slay, caused by the extra distance it
has to travel. This lengthening of the crank has obviously much more to
do with the increase in velocity of the slay than the shortening of the
arm has.
The longer the crank the further back from the cloth will the slay be
taken, and assuming that the shed is open for the shuttle when the
crank is at the bottom centre, a long crank is obviously more suitable
for a wide loom, as, having to move further back, it will allow a
longer time for the shuttle to pass through the shed than a short crank
would; therefore the wider the loom, the longer the crank is required
to be to allow time for the shuttle to pass.
The time allowed for the passage of the shuttle may also be increased
by using a short arm so as to increase the eccentricity of the slay.
The longer the crank, the greater the velocity of the slay, therefore
a long crank is suitable for _heavy_ work, as it stores up more force
in the slay than a short one. The force may also be increased by
shortening the crank-arm, thus increasing the eccentricity of the slay.
[Illustration: FIG. 62.]
The position of the crank-shaft in relation to the connecting pin
has some effect upon the _eccentricity_ of the slay’s movement. Fig.
62 shows this, but to see clearly the effect it would be advisable
to make an accurate drawing to a large scale. Four positions of the
crank-shaft are shown. The one on the line A is just a little below
the level of the connecting pin, so that the pin moves as nearly as
possible on the line A when making the front quarter of its stroke.
The circle on the line B is the position where the pin moves as nearly
as possible on line B when at the back quarter of its stroke; D is any
higher plane, and C any lower one. Divide the stroke of the connecting
pin LR into four equal parts, and from S, with the crank-arm in the
compasses, cut the circles with the arc E, and from T cut the circles
with the arc F. It will be found that in the circle A, OP is slightly
longer than in any of the other circles; therefore this is the position
where the beat up is slowest. It will also be found that in the circles
B and C there is scarcely any difference in OP, therefore sinking the
crank-shaft from within reasonable limits makes very little difference;
if anything, there is a slight decrease in the size of OP as the plane
is lowered, but it is very slight, and the increase in the velocity
of slay would also be very slight. On the other hand, by raising the
crank-shaft to D a considerable increase in the velocity of the slay in
beating up takes place, as it will be found that in this circle OP is
much less than in the others.
At the back of the stroke it will be found that in the plane B the
distance XY is least; therefore there is here the least dwell of the
slay at the back of its stroke with the shaft in this position. This
is because the pin moves as nearly as possible on the line B whilst
the crank is at the back part of its stroke. As the crank is raised or
lowered the dwell at the back increases slightly.
Reversing the direction of the loom makes a difference in the beat-up.
It will be found that in the circle A, OP and ON are about equal,
therefore there will be scarcely any change in the velocity of beat-up
by reversing the loom; but as the shaft is lowered ON will be found to
become less than OP, and therefore a quicker blow is given by reversing
the loom if the shaft is in this position. If the shaft is raised, as
in the case of circle D, it will be found that ON becomes _greater_
than OP; therefore with the crank above A, reversing the direction of
the loom will cause a slower and weaker beat-up.
In the diagram, Fig. 62, the crank and crank-arm are the same length
for each position, the centre of the shaft being indicated by the
dotted arc.
_Timing of the Primary Movements._
[Illustration: FIG. 63.]
The primary movements, shedding, picking, and beating up, are timed
differently in relation to each other in weaving different classes
of fabrics. For plain cloths, or other cloths where a good cover is
required--that is, where the warp has to be spread--the crank should be
set about the top centre when the healds are crossing each other. At
Fig. 38 the loom is timed in this manner. When so timed it is obvious
that the shed will be considerably or altogether open when the reed is
in contact with the cloth. By sinking the centres of the healds below
a line drawn from the temple to the back rest, the upper portion of the
shed is always slack, and if the pick is beaten up in a crossed shed,
the loose ends of the warp are spread between the taut ones. In Fig.
63 the straight line AB is drawn from the front carrier A to the back
carrier B. The centres of the healds when level are on the line ACB,
the point C being a little way below the line AB. When one stave is
lifted a certain distance and the other goes down the same distance, it
is obvious that the upper portion of the warp will be slacker than the
lower portion, because the line ADEFB is shorter than ADGFB, and when
the reed beats up with the warp in this position the slack ends are
spread between the taut ones, thus giving a good cover to the cloth and
preventing the reed marks from showing. Each set of ends alternately
becomes slack.
Another advantage of beating up when the shed is crossed or partly
open for the succeeding pick is that the pick is held more firmly in
position than when the shed is not crossed, and therefore the picks can
be got in better.
In twilled cloths the boldness of the twill is somewhat affected by
the warp being spread, and these cloths are often preferred when made
without the healds having been sunk.
[Illustration: FIG. 64.]
If the dwell on the tappet is equal to one-third of a pick, as in Fig.
64, the line D will mark the point of the tappet when the crank is at
the top centre. When the crank has made one quarter of a revolution and
is at the front centre with the reed in contact with the cloth, the
point E will be acting on the treadle bowl. It will be seen that here
the shed is almost fully open. When the crank is at the bottom centre
the point G will be acting on the bowl, and the shuttle should just
be entering the shed. When the point H of the tappet is acting on the
bowl the shed will be commencing to close, and the shuttle must be just
leaving the shed. When the point I is acting on the bowl the crank will
be at the back centre, and when the crank reaches the top centre the
healds will be again level.
If the dwell on the tappet is more than one-third pick, and at the
commencement the crank is set on the top centre with the healds level,
the shed will keep open longer for the shuttle to pass through, and
would be more open when the crank reached the front centre. It will
be obvious that for a wide loom a longer dwell is required than for a
narrow loom.
By having the shed fully open before the shuttle enters the shed, the
warp is spread and a good cover put on the cloth, but all this dwell
is taken off the time which would otherwise be allowed for opening and
closing the shed, and therefore means extra strain on the warp.
If it is not necessary to spread the warp, the shed need not be fully
open until the shuttle is entering the shed. In this case the greatest
possible amount of time is allowed for opening and closing the shed,
thus putting as little strain as possible on the warp.
_Speed of Tappets._
As previously stated, the bottom shaft in the loom, being the one used
for picking, revolves at one-half the speed of the crank-shaft, and
therefore plain cloth tappets may be fastened on the bottom shaft.
Tappets of more than two picks to the round are usually fixed on a
counter-shaft, S (Fig. 65), in looms with inside tappets. Sometimes
the wheel E is geared directly into the wheel C on the bottom shaft,
but usually a carrier-wheel, D, is used to convey the motion from the
bottom shaft. The number of teeth in the carrier wheel has no effect
on the speed of the tappets, as it is used simply to fill up the space
between the bottom and counter-shafts.
[Illustration: FIG. 65.]
If the wheel on the crank-shaft A contains 45 teeth, and the wheel B 90
teeth, C 40 teeth, and E 60 teeth, the tappet-shaft S will be making
one revolution for three revolutions of the crank-shaft; therefore
these wheels will do for three-end twill tappets. This may be proved by
multiplying the drivers together and the drivens together, and dividing
one by the other, thus--
(90 × 60)
--------- = 3
(45 × 40)
It is usual to place two or three wheels on the bottom shaft of the
loom, so that any one of them may be geared into the carrier wheel D,
each giving the required speed for different tappets. If a 40 wheel,
a 30 wheel, and a 24 wheel are placed on the bottom shaft in such a
manner that they can be moved along the shaft and any one of them be
geared into the carrier wheel, any 3, 4, or 5 pick tappets can be
driven with these wheels. We have seen that a 40 wheel at C gives three
picks to the round.
Suppose the 30 wheel at C is geared into the carrier wheel, we get--
(drivens 90 × 60)
----------------- = 4,
(drivers 45 × 30)
or the relative speed of the tappets and crank-shaft are as 1:4;
therefore these wheels may be used for any tappets with four picks to
the round.
If the 24 wheel is at C, we get:
drivens 90 × 60
------- = 5,
drivers 45 × 24
and thus we get the proper rate of speed for tappets five pick to the
round.
Some loom makers use the wheel E as a change wheel. With a 24 wheel C
and a 36 wheel E we get three picks to the round, thus--
drivens 90 × 36
------- = 3
drivers 45 × 24
With a 24 wheel C, a 48 wheel E gives 4 picks,
With a 24 wheel C, a 60 wheel E gives 5 picks,
With a 24 wheel C, a 72 wheel E gives 6 picks.
_Example._--Find the number of teeth for the wheel C on the bottom
shaft to drive tappets seven picks to the round, wheel on tappets
63 teeth.
90 × 63
------- = 18 wheel. _Ans._
45 × 7
Woodcroft’s tappets, as a rule, are driven directly from the
crank-shaft. As these tappets are usually of a large circumference,
a large wheel on them is of no disadvantage, although sometimes
intermediate wheels are used.
If the tappets are twelve to the round, and the wheel on the tappets
contains 192 teeth, a driving wheel of 16 teeth will be required on the
crank-shaft.
192
--- = 12 picks to the round
16
For driving outside tappets, as in Fig. 39, a driving wheel on the
crank-shaft and two intermediate wheels are generally used. The
tappets are placed on the bottom shaft outside the loom, but they are
loose upon the shaft, and can, of course, be made to revolve at a
different speed to the shaft, either in the same or in the opposite
direction. This system of driving the tappets is shown at Fig. 66. The
wheel A, on the crank-shaft, drives the wheel B, on an intermediate
stud; the wheel C, on the same centre, drives the tappet wheel D.
[Illustration: FIG. 66.]
To find the wheel on the crank-shaft, or the first driver, the other
wheels being as follows: first driven wheel, B, 36 teeth; second
driver, C, 12 teeth; tappet wheel, D, 120 teeth.
Multiply the two driven wheels together, and divide by the given driver
multiplied by the picks to the round, thus--
36 × 120
-------- = 40 first driver, A.
12 × 9
To find the second driver for eight picks, the other wheels being:
first driver, A, 20; first driven, B, 40; second driven, D, 60.
The given driver multiplied by the picks to the round, 20 × 8 = 160;
the drivens multiplied together, 40 × 60 = 2400; 2400 ÷ 160 = 15 wheel
required.
To find either of the driven wheels, multiply the two drivers and the
picks together, and divide by the driven given wheel, thus--
_Example._--Find the wheel for the tappets, D, for 10 picks to
the round, the other wheels being: first driver, 16 teeth; first
driven, 32 teeth; second driver, 20 teeth.
16 × 20 × 10
------------ = 100 wheel required
32
To find both intermediate wheels, multiply the given driver by the
picks to the round, and as the product is to the teeth in the tappet
wheel, so is the required driven to the required driver.
_Example._--Find the two intermediates for 10-pick tappets, if the
wheel on the crank-shaft has 18 teeth, and the wheel on the tappets
120 teeth. The 18 × 10 = 180, and therefore the two required
wheels must be in the proportion of 180 to 120, the former being
the driven wheel. Thus a 36 driven and a 24 driver will give the
required speed to the tappets. That this is correct may be seen
from the following:--
18 × 24
-------- = 10 picks
36 × 120
That the required wheels must be in this proportion will be apparent
from the fact that if the wheel B has ten times the number of teeth in
A, then B is revolving at the speed at which the tappets are to move;
therefore if the wheel C has the same number of teeth that D has, the
speed of the tappets will remain the same.
FAST-AND LOOSE-REED LOOMS.
One of the most important motions in the power loom is that by which
the loom is stopped automatically when the shuttle is caught in the
shed or for some reason does not enter the shuttle-box. A motion of
this kind has always been considered necessary since the introduction
of the power loom. If the shuttle be caught in the shed as the reed is
beating up, it is obvious that great damage to the warp must result
unless the loom is brought to a sudden stop or the reed thrown out.
The oldest form of protector is the “stop rod.” In this the reed is
fast, and if the shuttle is caught in the shed or flies out, the loom
is brought to a sudden stop before beating up. Fig. 67 will illustrate
the principle of this motion. If the shuttle enters the box safely it
presses back the swell S, which projects inside the box and is held
there by a spring. As the swell is pressed back it raises the lever B
above the frog F as the slay beats up. If the shuttle for any reason
does not enter the box, the swell is not pressed back, and as the slay
moves forward in beating up, the lever B catches the frog F, which
is moved a little and applies the brake G, and also knocks off the
loom handle H, which removes the belt on to the loose pulley. Before
the application of the brake to this motion the frog was fixed to
the framework of the loom, and it will easily be understood that the
concussion caused many breakages. A stop rod protector was patented in
1791, but the brake was not applied until 1840 or thereabouts.
[Illustration: FIG. 67.]
The loose reed is a better way of preventing damage to the warp by the
shuttle being caught. If the shuttle is caught in the shed it throws
out the reed and stops the loom. Its action will be understood from
Fig. 68. A rod, C, runs underneath the shuttle-race at the back of the
slay, and the finger B is fastened to it. The reed is held in position
by a board, A, which is also connected to the rod C, as shown in the
diagram. If the shuttle is caught in the shed, it presses back the reed
and the board A, and lifts the finger B to the upper side of the frog
F, and as the slay moves forward it throws the board A further back and
the reed out at the bottom, and the lever H is brought into contact
with the loom handle, and the loom is stopped. If the shuttle passes
safely through the shed, the reed is not pressed back, and the finger
F comes under the frog as the slay gets to the front of its stroke,
and holds the reed comparatively fast. The disadvantage of the loose
reed is that the reed is not sufficiently firm to put a large amount of
weft into the cloth, but improvement is being made in this respect, and
loose-reed looms are to-day made for weaving fabrics for which it was
formerly necessary to have fast reeds.
[Illustration: FIG. 68.]
The invention of the loose reed is generally attributed to Mr. James
Bullough. It was invented about 1842.
THE WEFT FORK STOP MOTION.
[Illustration: FIG. 69.]
One of the most useful adjuncts to the power-loom is the motion for
stopping the loom when the weft breaks or runs out. Fig. 69 will
explain the principle of this useful contrivance. The grid A is placed
at the side of the reed between the reed and the shuttle-box, and the
fork is so placed that as the grid moves forward the prongs of the
fork pass through it. When the weft comes between the fork and the
grid it raises the end of the fork E, out of the way of the hammer
H, which is moved forward every two picks by a cam or lifter, D, on
the bottom shaft of the loom. If the weft breaks or runs out the fork
will of course pass through the grid, and it is so balanced that the
hook E will be caught by the hammer and the loom handle knocked off.
The invention of the Weft Fork Stopping Motion is claimed by several
persons, but it was perfected about the year 1842, when the brake was
applied to it. The action of this brake is illustrated at Fig. 70.
When the handle is pushed sideways in starting the loom it lifts the
rod R and the lever L, and thus takes the brake off. When the handle
is knocked off by the weft fork being caught, the lever L drops and
the brake is applied. The brake power can be regulated by altering the
position of the weight on the levers.
[Illustration: FIG. 70.]
In looms with change boxes at both sides the weft fork is often placed
in the middle of the loom. It is obvious that when several shuttles
are used there will always be some weft threads opposite the grid in
the ordinary weft fork motion, and this renders it inoperative in this
class of looms. It is therefore necessary to have a fork to feel for
each pick separately.
TAKING-UP OR COILING MOTIONS.
There are two distinct classes of taking-up motions--the positive, and
the negative or drag motion. In the former the cloth is taken up a
small but regular distance each pick, and the number of picks per inch
can be regulated to a fraction. Fig. 71 is the common form of positive
take-up motion. A ratchet wheel or “rack wheel,” A, is moved forward
one tooth every pick by a click or catch, M, operated by a projection,
G, on the slay sword. As the slay moves forward the rack wheel is moved
one tooth, and the holding catch or detent N prevents it from going
back. There are five wheels in the train, and the names usually given
to them are as follows: A, rack wheel; B, change wheel; C, stud wheel;
D, stud pinion; E, beam wheel. The emery taking-up roller is marked F.
The cloth, as it is woven, is drawn forward by the emery roller and is
wound upon the cloth roller, which is pressed against the emery roller
by weighted levers, and is turned by friction.
[Illustration: FIG. 71.]
The speed at which the emery beam roller is turned regulates the
number of picks per inch, and as changes are constantly required in
most weaving mills, the wheel B is usually taken as a change wheel.
As this wheel is a driver, a smaller wheel will make the emery roller
move slower, and therefore more picks will be put in the cloth, and a
larger wheel will drive the emery roller quicker, and as a consequence
a smaller number of picks will be put in. If the rack wheel has 50
teeth, the stud wheel 120 teeth, the stud pinion 15 teeth, and
the beam-roller wheel 75 teeth, the beam roller being 15 inches in
circumference, and if the change wheel used has 25 teeth, the number of
picks per quarter-inch will be 20.
This may be proved by multiplying the drivers together and by the
circumference of the emery beam roller in quarter-inches for a divisor,
and multiplying the drivens together for a dividend: the quotient will
be the number of picks per quarter-inch.
DRIVERS.
25
15
---
125
25
---
375
60 quarter-inches
----- in beam
22500
DRIVEN.
50
120
----
6000
75
------
22500)450000(20 picks per
45000 quarter-inch
------
0
When the cloth is taken out of the loom, rather more than this number
of picks will be counted, as there is not the same tension as when the
cloth is being woven. It is usual to allow about 1½ per cent. for
this shrinkage.
For the purpose of easy calculation the dividend of the loom is
obtained; that is, the change wheel required to give one pick per
quarter-inch. By using this as a dividend and dividing by the number
of picks required in a quarter-inch, the quotient will be the change
wheel required; and, _vice versâ_, by dividing by the change wheel, the
number of picks given by that wheel can be obtained.
To find the dividend of a loom--
Multiply the rack, stud, and beam wheel together for a dividend, and
the stud pinion and the number of quarter-inches in a circumference of
the emery beam for a divisor, and the quotient will be the mathematical
dividend. Add 1½ per cent. to this for the practical dividend.
With the wheels given in Fig. 71 the dividend will be as follows:--
15 stud pinion
60 quarter-inches in circumference of beam
---
900
50 rack wheel
120 stud wheel
----
6000
75 beam wheel
----
900)450000(500 mathematical dividend
4500
------
00
500
7 = 1½ per cent. for shrinkage
---
507 =practical dividend=.
Having the dividend, it is only necessary to divide by the picks to
obtain the change wheel required, or to divide by the teeth in the
change wheel to obtain the picks which it will give, thus--
507 507
picks --- = 39 change wheel change wheel = --- = 25⅓ picks.
13 20
The following are the wheels used by various loom makers:
+------+------+-------+------+-------------+---------+
| | | | |Circumference| |
|Rack |Stud |Stud |Beam | of beam in |Dividend.|
|wheel.|wheel.|pinion.|wheel.| inches. | |
+------+------+-------+------+-------------+---------+
| 50 | 120 | 15 | 75 | 15 | 507 |
| 60 | 120 | 15 | 75 | 15 | 609 |
| 50 | 146 | 14 | 90 | 15 | 794 |
| 50 | 100 | 12 | 75 | 15 | 528 |
| 60 | 100 | 12 | 75 | 15 | 634 |
+------+------+-------+------+-------------+---------+
_Example._--Find the dividend of a loom with a rack wheel 60 teeth,
stud wheel 100 teeth, stud pinion 12 teeth, beam wheel 75 teeth,
beam 15 inches circumference.
rack stud beam wheel
60 × 100 × 75
------------------ = 625 mathematical dividend
12 × 60 9 = 1½ per cent.
stud quarter-inches ---
pinion in beam 634 practical dividend.
It is not possible by changing one wheel only to obtain any number
of picks or fraction of a pick, as will be seen from the following
examples:--
507
picks --- = 12·67
40
507
picks --- = 12·12
41
507
picks --- = 12·07
42
For the lower number of picks the motion does fairly well, but for the
higher numbers of picks the changes cannot be made with sufficient
exactitude by changing a single wheel. Even in the lower picks it is
now required to make the smallest fractional changes.
An improved arrangement of wheels is now largely adopted. This is
Pickles’ motion. Fig. 72 shows the train of wheels. The change wheel B
is in this case a driven wheel, and therefore if a larger wheel is used
it will give a larger number of picks in the cloth, and if a smaller
wheel is used it will give a smaller number of picks; so that if the
wheels are so proportioned that the change wheel B has the same number
of teeth that there are picks per quarter-inch, it will always remain
so, whatever size the wheel is. If a 20 driven wheel gives 20 picks, a
30 will give 30 picks, and so on.
The wheel A is also changed, and this is usually called the “standard”
wheel. This is a driver wheel, and therefore a smaller wheel gives
more picks, and _vice versâ_. The wheels are so proportioned that if
A, the standard wheel, has nine teeth, each tooth in B, the change
wheel, represents one pick, and therefore, this wheel being a driven,
the number of teeth in it will also represent the number of picks per
quarter-inch. If an 18 standard wheel is used, it is obvious that the
emery beam will be driven twice as fast, therefore each tooth in the
change wheel B will then represent half a pick per quarter-inch. With a
27 standard each tooth in the change wheel B will represent one-third
of a pick. With a 36 standard each tooth in B will represent a quarter
of a pick per inch.
[Illustration: FIG. 72.]
The wheels mostly used are those in the diagram, and supposing we have
a 36 standard and a 45 change wheel, and taking the emery beam as 15·05
inches in circumference, we get--
B
24 × 45 × 89 × 90
-------------------- = 11·088
36 × 24 × 15 × 60·20
A ·166 = 1½ per cent. for shrinkage
------
11·254 picks per quarter-inch.
Thus with a 36 standard a 45 change wheel, B, gives 11¼ picks per
quarter-inch, or each tooth in the change wheel gives a quarter of a
pick per quarter-inch.
By changing these two wheels any fraction of a pick can be obtained.
Thus if 13½ picks per quarter-inch are required, the wheels used would
be an 18 standard and a 27 change wheel. For 13⅔ picks a 27 standard
and a 41 change wheel would be used, and so on.
The following examples will fully illustrate the principle of this
motion:--
+-------------+--------+------+
| Picks per |Standard|Change|
|quarter-inch.| wheel. |wheel.|
+-------------+--------+------+
| 20 | 9 | 20 |
| 15½ | 18 | 31 |
| 14⅓ | 27 | 43 |
| 14⅔ | 27 | 44 |
| 13¼ | 36 | 53 |
| 13¾ | 36 | 55 |
| 12⅕ | 45 | 61 |
+-------------+--------+------+
It is not always customary to change the wheels in the above manner, as
a different value is often given to each tooth in the change wheel by
altering the standard wheel, otherwise than by multiples of nine.
Any number may be made the basis of a train of wheels of this kind;
there is no reason why it should be nine more than any other number,
and in adapting looms from the ordinary five-wheel motion to this
principle, it is not necessary to get all new wheels, as sow of the old
ones may be made to form part of the train.
There are several kinds of negative or drag take-up motions. One of
the older forms is that given in Fig. 73. A lever, AB, centred at C is
weighted on the arm B. A small cam, D, on the crank-shaft presses down
A every pick and lifts the catch E, which operates the ratchet wheel
F. As the weights drop they act as a drag upon the ratchet wheel. A
small pinion on the same centre as the ratchet wheel drives the wheel
G on the cloth beam. The cloth in a negative motion is wound directly
on to the cloth beam, and thus there is no risk of damaging the finer
fabrics, as is the case when an emery beam is used, as in a positive
motion. The number of picks put in the cloth is regulated by the
weights on the lever B; the greater the weight the less the number of
picks, and _vice versâ_.
[Illustration: FIG. 73.]
The action of a negative motion is as follows:--As the slay beats up,
the cloth between the cloth beam and the reed is slackened a little,
and the weights on the lever at that moment act as a drag upon the
ratchet wheel F. The holding catch is usually a double one, and will
hold the ratchet wheel when taken forward the space of half a tooth.
By increasing the drag upon the ratchet wheel, a slighter blow from
the slay will enable the weights to act, and thus less weft is put
into the cloth. If a loom is regulated so as to put a certain number
of picks per inch into the cloth of a given count of weft, and weft of
a finer count is then used, it is obvious that the number of picks per
inch would be increased. If the weft varies in thickness the negative
motion compensates for this somewhat, by putting more picks in where it
is thinner, and thus a more even thickness of cloth is produced than
where a positive motion is used.
As the cloth is wound on the beam the circumference of the latter
gradually increases, and consequently there would be a gradual
alteration in the amount of weft put into the cloth, owing to the
difference in leverage. It is necessary, therefore, to count the cloth
and adjust the weights at intervals in order to keep the number of
picks regular.
[Illustration: FIG. 74.]
[Illustration: FIG. 75.]
Another kind of negative take-up motion is shown at Figs. 74 and 75.
This is now more generally used than the other kind. The cloth beam
A is driven by a screw, S. The ratchet wheel B is fastened to the
screw-shaft, and the method of operating the ratchet wheel will be seen
from Fig. 75, which is another view of the mechanism. A short lever,
E, is attached to the rocking shaft K, and as the slay moves backwards
from the cloth the weights W are lifted a little, and when the slay
moves forward, the weights, acting through the catch M, will take the
ratchet wheel forward a tooth, or half a tooth, as the case may be.
There is usually a double-holding catch N, which will hold the wheel
if taken forward half a tooth. When the ratchet wheel has made one
revolution, the wheel on the cloth beam will only have been moved one
tooth by the screw, so that the required slow movement of the cloth
beam is obtained by very simple means. There is a hand wheel, P, for
unwinding the cloth readily. The negative motion is used principally
in weaving the heavier classes of cotton fabrics and those in which
there is a large number of picks per inch, such as velvets, and similar
fabrics. Its advantages are that the cloth is wound directly on to
the cloth beam, and cannot therefore be injured by an emery beam, and
that it makes the cloth of a more even thickness, as it compensates
for any variation in the thickness of the weft; and its disadvantages
as compared with a positive motion are that it requires frequently
adjusting (less frequent, of course, when a very large number of picks
are put in, as in velvets), and that it does not put a perfectly
regular number of picks in the cloth, as a positive motion does. This
latter is the chief objection to it, as even in the lighter makes of
common velvets a positive motion is preferred on account of its giving
a more evenly picked cloth. In silk looms, where it is absolutely
necessary to dispense with an emery beam, a very large cloth beam is
used, and the cloth is wound directly on to the cloth beam although
the take-up is positive. The cloth beam is sometimes over a yard in
circumference, so that it will hold a fair length of cloth without
making much difference in the number of picks. The cloth is taken
off the beam frequently, or the gradual change in the thickness of
the cloth beam would cause the piece to get too thin. This would, of
course, not do for cotton goods.
Another ready method of obtaining any required pick in a positive
motion is used in the East Lancashire districts. Seven wheels are used,
as in Pickles’ arrangement, but the ordinary wheels of a 507 dividend
(or other dividend) are used, and in addition the two wheels B and
C, as in Pickles’ (Fig. 72), are introduced. The wheel B, the driven
wheel, is called the standard in this arrangement; and suppose it is
required to put 15 picks per quarter-inch in the cloth with the rack
wheel 50 teeth, stud wheel 120, stud pinion 15, beam wheel 75, beam
15 inches circumference. The standard used is a 24--this, it must be
borne in mind, is in this case a driven wheel. Then by multiplying the
dividend of the five-wheel motion, viz. 507·5, by 24, the teeth in the
standard, and dividing by the picks per quarter-inch required, we get
the product of the two drivers, A and C, thus--
507·5 × 24 standard B
--------------------- = 812
15 picks
This 812, then, is the product of the two drivers, and any two
convenient wheels which, multiplied together, give this number can be
used--thus 812/28 = 29. Therefore the two drivers may have 28 and 29
teeth respectively. The two wheels are found by experiment. If the
dividend of the five wheels is 609 a 20 standard wheel is used, and
the same drivers as in the preceding case will do. If it is required
to change only one wheel, and to have the arrangement such as to
give an exact number of picks, or half-picks, or quarter-picks, in
the quarter-inch of cloth, by taking the two drivers A and C of such
numbers that their product amounts to 507, the number of teeth in the
driven wheel B will always equal the number of picks per quarter-inch
exactly. Thus 507/13 = 39. Therefore if the drivers A and C have
respectively 13 and 39 teeth, every tooth in the driven wheel B will
represent one pick per quarter-inch.
Suppose half-picks are required exactly, the method of obtaining the
wheels is as follows:--Multiply the 507·5 by 2, which equals 1015, then
find two convenient wheels which, multiplied together, produce this
number; 35 × 29 = 1015, and the two drivers A and C may be 35 and 29.
This will cause every tooth in the driven wheel B to represent half a
pick exactly.
Thus with a 35 wheel A, and a 29 wheel C, a 31 wheel B will give 15½
picks per quarter-inch, the other wheels being the same as in an
ordinary 507 dividend motion.
The following examples will prove this:--
50 rack × 31 B × 120 stud × 75 beam wheel
------------------------------------------- = 15·27
35 A × 29 C × 15 pinion × 60 quarter-inches
and 15·27
0·23 = 1½ per cent. shrinkage
-----
15·50 picks.
When quarter-picks are required exactly, by changing one wheel
only--multiply 507·5 by 4, and the product of the two drivers A and C
must equal this. Then every tooth in the driven wheel B will represent
a quarter-pick per quarter-inch.
There are many methods of letting off the warp positively, but none are
likely to succeed in displacing the older and quite satisfactory method
of levers, ropes, and weights. The very fact of making the let-off
positive, causes too great a rigidity in the hold of the warp, which
is detrimental to the yarn. The frictional let-off is not likely to be
replaced in cotton goods weaving unless it be in some of the heavier
kinds of fabrics. Where it is a question of putting in as much weft as
possible, the positive let-off has an advantage.
CHAPTER III
_DROP-BOX LOOMS_
Where more than one kind or colour of weft is used in a fabric, it is,
of course, necessary to change the shuttles automatically. Sometimes
two or more different counts of weft of the same colour are used, and
sometimes different colours of weft. Checks of all kinds, extra weft
spots, and others are the chief classes of fabrics which require change
boxes.
[Illustration: FIG. 76.]
The oldest and commonest form is the Diggle’s chain motion illustrated
at Fig. 76. The number of boxes used in this motion is either 2, 3,
or 4. It would be possible to use more, but it is not usually done
with this arrangement for operating them. A lever, AC, is centred at C
(Fig. 76), and the friction bowl B on this lever is moved upwards by a
chain, composed of links fastened together on pins, which work round a
barrel, D. These links are of different sizes, according to the number
of boxes used. The smallest link leaves the top box in a line with the
shuttle-race, and the other links are of such a size as to raise either
the second, third, or fourth boxes (assuming that there are four) into
this position. The general method is to raise the boxes one at a time,
and drop them all together, but this is not compulsory. It will be
seen that the motion of the boxes is not positive downwards--that is,
the boxes drop by their own weight, and are not mechanically forced
down, as in Wright Shaw’s or Whitesmith’s motions--and it will be well
understood that there will thus be a limit to the speed at which the
loom can be run. The method of turning the barrel D which carries the
chain is as follows. A wheel, E, on the crank-shaft drives a larger
wheel, F, above it. On the face of this wheel, F, is a rim and two
projections, PP, or, it may be, only one projection. These projections
or pins gear into the star wheel G, which is fastened to the barrel
carrying the chain, and therefore when the star wheel is turned one
tooth, or one-eighth of a revolution, it will move the chain a space
of one link. The wheel E on the crank-shaft often has one-fourth the
number of teeth contained in the wheel F; therefore, if there are two
pins or projections, PP, in the circumference, the star wheel will be
moved one tooth every two picks, and the boxes may be changed so often
by making the chain accordingly. The lever M, which is centred at R,
has the boxes attached to one end, and the other end may be pressed
down by the foot when it is required to lift the boxes for any purpose
when the loom is stopped. Supposing the wheel E to have 15 teeth and
F 60 teeth, if there are two projections, PP, on the face of F, the
shuttle may be changed every two picks, but if there is only one
projection or pin, there may be a change every four, or a multiple of
four picks.
The chief disadvantage of this motion in the form given at Fig. 76 is
that the chain becomes very cumbersome if a long pattern is required.
To obviate this, the projections PP are, in an improved motion, made
so that they can be withdrawn from gear with the star wheel. This
is effected by a clutch motion which is subsequently described in
connection with the “pick-and-pick loom.” With this improvement, each
link in the chain may be made to represent any number of picks, the
number being regulated by a small chain of metal cards, and thus larger
patterns may be made without the long heavy chains which are required
in the ordinary “Diggle.”
The Diggle’s chain principle, although suitable for some types of
looms, is not an ideal motion, as the downward movement of the boxes
is negative. The boxes have nothing to force them down but their own
weight and the weight of the levers connected with them, and this
necessitates the loom being run at a slower speed than is the case
with some of the positive drop-box motions. Of this latter kind Wright
Shaw’s motion is one of a great variety of different types, and has
been in use for a long time.
WRIGHT SHAW’S DROP-BOX.
The principle of this motion will be understood from the diagram,
Fig. 77. The essential feature of this invention is a forked rack, G,
suspended from the free end of a treadle lever, E, fulcrumed at F,
and carrying a bowl or runner, D, near the centre. At one end of the
second motion or picking shaft, A, of the loom, are two cams, B and C,
either of which may be brought underneath the treadle bowl at will, so
as to raise the treadle and forked rack once during each revolution of
the picking shaft, corresponding to two picks. Passing midway between
the two prongs, H, H′, of the fork is a short shaft, upon which are
secured two toothed wheels, I and J. Wheel I is so placed that the
teeth on either side of the rack may be put into engagement with its
teeth just before the fork rises, so as to turn the wheel in either
direction; or the rack may occupy a neutral position when rising,
in which event the wheel remains stationary. In any case, the racks
are always clear of the wheel when descending. Immediately in front
of wheel I is another similar wheel J, whose teeth are in permanent
engagement with those of a rack, K (an extension, L, of which supports
the shuttle-boxes, M). Thus, if rack H′ is put into gear with wheel I,
boxes will be depressed as the rack rises; but if rack H operates, the
boxes will be raised. One box, or two boxes, only, may be either raised
or dropped at one change, according to which rack and which cam is put
into operation. The smaller cam moves one box, and the larger cam two
boxes, either up or down.
[Illustration: FIG. 77.]
The selection of racks and cams is made by pattern cards (detached)
which pass over an octagonal prism, N. The cards are presented
separately, once in two picks, to three selecting needles, 1, 2, 3.
The two outer needles, 1, 3, are attached one at each end of a double
arm secured at the top of a long vertical shaft, O, the bottom of
which communicates with the forked rack G. Thus a depression of boxes
is effected by a blank part of a card pressing against needle 1, and
an elevation of boxes by pressing back needle 3. Shaft O is loosely
contained within a long tube or sleeve, P, which carries a short arm,
R, at the top, and a forked clutch, Q, which acts upon the boss of
cams, B and C. If it is desired to move two boxes, needle 2 is pressed
back, thereby causing an inclined piece, S, secured to it, to act upon
arm R so as to slightly turn the sleeve P, and move the larger cam C
under the treadle bowl at a time when the short side of the cam is
uppermost, as indicated in the diagram, Fig. 77. At one point, the
larger and outer cam is slightly lower than the smaller one, and can be
readily moved under the bowl.
The various changes which can be made by this motion may be seen by
referring to the cards at Fig. 77. When there is a blank opposite the
first needle only, the rack H′ is pushed to the left and the boxes are
moved “down one.” When there is a blank opposite the third needle only,
rack H is moved to the right and the boxes are forced “up one.” When
there are blanks opposite the first and second needles, they are pushed
backward, thus moving rack H′ to the left, and also forcing the larger
cam under the treadle bowl, in which case the boxes will be moved “down
two.” When there are blanks opposite the second and third needles, they
are pushed backward, and the boxes are “raised two.” When there are
three holes in the card, the racks, when lifted, miss the wheel, and
there is “no change” in the boxes. It will be seen that the boxes may
be moved either up or down, a space of one or two boxes only at a time.
There may be more than three boxes, as many as five being regularly
used; but if there were five, it would not be possible to change from
the first box to the fourth or fifth. The greatest change which can be
made is from the first to the third, fourth to second, and so on.
WHITESMITH’S DROP-BOX.
[Illustration: FIG. 78.]
[Illustration: FIG. 79.]
[Illustration: FIG. 80.]
The principle of Whitesmith’s motion is probably the best for any
number of boxes. It is usually made for four, and the change may be
made with certainty from one box to any other. The arrangement for
working four boxes in a loom is illustrated at Figs. 78, 79, 80. The
principle will be best understood by referring first to Fig. 80. The
four different positions of the boxes are here shown. The boxes are
connected to the ring or strap of an eccentric at the point E, and
at A the position of the parts is shown when the boxes are at their
lowest point. The eccentric, F, on the shaft has a lift of one box,
and therefore by causing it to make half a revolution intermittently
every two picks, the boxes would be alternately lifted and dropped a
space of one box, as will be seen by referring to C (Fig. 80), where
it has made half a revolution from its position at A. It will be seen
that E is one box higher at C than at A. Starting again from the first
position, as at A, by turning the outer ring halfway round and leaving
the eccentric stationary, there will be a lift of two boxes. This is
shown at B (Fig. 80). Again starting with the first position, as at A,
if we turn the outer ring halfway round, and at the same time turn the
eccentric F half-round, we lift a space of three boxes--that is, from
the first to the fourth box. The position of E in this case is shown
at D (Fig. 80). We thus see how from the bottom box any other of the
four can be reached. By turning the eccentric halfway we lift one box,
by turning the ring halfway round we lift two boxes, and by turning
both ring and eccentric halfway round we lift three boxes. If we are at
the third box, as at B (Fig. 80), and we wish to reach the second box
or one lower, by turning the eccentric half a revolution and the ring
half a revolution we shall get the position required. It will thus be
seen that any one of the four boxes may be reached at will. At Fig. 79
another view of the eccentrics and boxes is given. The wheel H is keyed
to the shaft on which the eccentric is fixed, and riding loosely upon
this shaft is another wheel, I, of the same size, to which a fork, K,
is attached. This fork fits on to a pin at the back of the ring, and
thus by turning the wheel I the ring can be moved independently of the
eccentric. If the wheel H is moved it moves the cam, and if the wheel
I is moved it moves the ring. Referring now to Fig. 78, the wheel H is
shown. This wheel is driven by a wheel, I (Fig. 79), twice its size. On
the face of the wheel L there are four pins, and by lifting the lever
OP at O, the pulling hook M is dropped round one of the pins, and the
hook being moved forward by the crank Q will cause the wheel L to make
a quarter of a revolution and the wheel H to make half a revolution,
and therefore the eccentric is moved half a revolution. On the same
stud as the wheel L there is another wheel exactly the same size and
with four pins; this wheel (which cannot well be shown in the diagram)
gears into the wheel I shown in Fig. 79. There is also another pulling
hook which works along with M. This second pulling hook is operated by
another lever like OP. There are two levers, X, which are lifted by
the cards, and by lifting X, either, or both, of the pulling hooks may
be dropped, and either of the wheels I or H (Fig. 79) turned half a
revolution, but always in the same direction.
The wheel L and its companion are prevented from turning too far by a
strong friction arrangement.
This motion may be adapted to work six boxes, or even more. For six
boxes there is another eccentric inside the first eccentric, which can
be worked independently; this will, of course, require a third pulling
hook, and so on.
Many loom-makers have patented arrangements on the same principle,
which do away with the pulling hooks M, and it is probably in this
direction that the motion may be improved.
The Whitesmith principle is simple, and positive throughout, and it is
difficult to see why it is not in more general use. It is generally
admitted by those who have had practical experience of drop-box looms
on this principle that it is the best. There are other drop-box
motions, but the foregoing are the chief kinds.
CIRCULAR-BOX LOOMS.
These are not used in the cotton trade to anything like the extent
they are in the woollen and worsted trades, especially in Yorkshire.
It is remarkable that this should be the case, as it is claimed for
circular boxes that they can be run at a higher speed than any other
kind. Circular boxes are usually made for six shuttles, generally
to move only one box at a time, but they are made to skip one box,
although the arrangement is by no means so simple or satisfactory as in
a well-made loom on Whitesmith’s principle, where the changes are made
from one box to another almost noiselessly. At Fig. 81 the mechanism of
a circular-box motion is shown. There are two hooks, A and B, which act
upon pins outside the boxes. When the hook A is pulled down the boxes
will be turned one to the right, and when B is pulled down they are
turned one to the left. A lever, EF, is connected with the lower part
of each hook, and another lever, M, is lifted every two picks by means
of a cam, C. The cards lift or drop the ~L~ lever QS at S, and so
the hook H can either be lifted or left down by the lifter M, and the
boxes can be turned one in either direction. A disadvantage of circular
boxes is that they cannot be used in fast-reed looms on account of the
difficulty of operating the stop rod from the back of the boxes. They
are therefore only used for weaving the lighter classes of fabrics.
[Illustration: FIG. 81.]
PICK-AND-PICK LOOM.
The majority of box looms are made with movable boxes at one side of
the loom only, so that single picks of any colour cannot be put in the
cloth at will. As it is very desirable in many fabrics to use single
picks of a colour or count of weft, it is necessary to have movable
boxes at both sides of the loom, and where this is the case it is usual
to have picking mechanism which will allow of several picks being made
in succession from either side of the loom. If the matter be carefully
thought over, it will be easily apparent that even with drop boxes
worked quite independently of each other at both sides of the loom,
if the picking mechanism is of the ordinary kind--viz. to pick once
from each side alternately--it would be impossible to obtain that
variety of changes in the shuttles which is in many cases necessary. In
a loom with two boxes at each side worked independently, it would be
impossible to obtain single picks alternately of two colours or counts.
But by being able to pick twice in succession from each side this can
be done. By going through all the changes possible with a given number
of boxes, the advantage of this kind of picking arrangement will be
very apparent, in the command it gives over any shuttle in the series
for any pick. It is therefore necessary to have the picking mechanism
aforementioned in order to allow of all the boxes being emptied at one
side if required. A loom of this character is called a “pick-and-pick”
loom; the picking motion is sometimes called a “pick at will” motion.
The loom which we take as an example is one on the Diggle’s chain
principle. There are two chains, placed at one side of the loom for
convenience. Both chains are on one barrel, A (Fig. 82). The chain for
working the boxes at the right-hand side of the loom operates the lever
B, and the left-hand chain operates the lever C, the fulcrum of both
levers being at D. When these levers are lifted they lift the levers E
and F, and when E is lifted it lifts the boxes at the right-hand of the
loom, and when F is lifted it lifts the left-hand boxes. The connection
of the left-hand boxes with the lever F is shown at Fig. 83. The shaft
G is placed under the loom, and the left-hand boxes are connected to
the lever H, which is fast to the shaft G. The lever F is also fast
to the shaft G, but the lever E rides loosely upon this shaft, which
merely serves as a fulcrum for E. From these two figures it will be
clearly understood how the boxes may be worked independently at both
sides of the loom by two chains placed side by side upon the barrel A.
[Illustration: FIG. 82.]
[Illustration: FIG. 83.]
[Illustration: FIG. 84.]
[Illustration: FIG. 85.]
In order to make each link in these chains represent any number of
picks, and thus prevent long cumbersome chains, the mechanism shown
at Figs. 84 to 87 is employed. The barrel A in Fig. 84 is the same as
barrel A in Fig. 82, and carries the chains for lifting the levers B
and C. At the end of the barrel the star wheel I is fixed, and this
star wheel is turned by the pins J. These pins are worked by a clutch
motion shown at Fig. 86, by which they can be withdrawn from gear with
the star wheel as desired. The pins KK are fixed, and turn one tooth
of the star wheel Y every pick, the wheel M having twice the number of
teeth contained in L, which is on the crank shaft of the loom. The star
wheel Y is fast to the end of a small octagonal barrel, which carries
a pattern chain N composed of small metal cards, and we have seen how
this barrel is turned one division every pick. Above this pattern chain
N a finger, O (Fig. 86), is placed, and is lifted up against a spring
every pick by the cam P on the face of the wheel M. When the finger
is up, the pins JJ are taken inside the wheel M, as shown at Fig. 86.
The cam P only raises the finger a sufficient length of time to allow
the barrel Y to be turned round, and if there is a blank in the cards
opposite the finger O when it is let down by the cam it will still keep
the pins J inside the wheel, and will thus prevent either of them from
engaging with the star wheel I, and will leave the boxes unchanged.
This can be repeated any number of picks. If a change is required in
the boxes, a hole is placed opposite the finger O, and when it is let
down the pins J project through the wheel M (as indicated by the dotted
lines in Fig. 86), and the star wheel I will thus be turned one tooth,
and the chain can make the change required in the boxes.
[Illustration: FIG. 86.]
[Illustration: FIG. 87.]
Fig. 87 is another view of the cam-shaped projection P, which raises
the finger every pick, and Fig. 85 is another view of the chain barrel
A. The letters in the six Figs. 82 to 87 inclusive refer to the same
parts in each case.
In this way the chains on A are rarely required to be very long, as one
link may be made to represent any number of picks from one upwards. Of
course a separate card on Y is required for each pick, but these are
very small, only about 1½ inch in length, and a large pattern can be
made with very little trouble.
When a Jacquard is used on one of these looms it is sometimes necessary
to work the pattern from the Jacquard cards. This can be done in a very
simple manner by covering the hole in the barrel carrying the cards N
with a metal plate, which is held over the hole by a spring. When a
change is required in the boxes, a Jacquard hook pulls the plate from
over the hole, and allows the finger O to drop, and thus causes the
star wheel I to be engaged by the pins J.
The picking mechanism in a pick-and-pick loom may be either over or
under pick. In the former the picking tappets are sometimes moved on
the shaft by a clutch arrangement. In the latter the top of the picking
treadle is movable. As the under pick is perhaps the best adapted for
this loom, we will describe it.
[Illustration: FIG. 88.]
Fig. 88 is a side view of the loom, and the top of the picking treadles
consists of a metal plate with the “shoe” S of such a shape as to give
the required force and character to the pick. This metal plate works
round a pivot, P. The treadles at both sides of the loom are the same
in this respect. At the back of the loom a rod, R, is connected to the
extreme ends of the loose plates or the treadles, and when one plate
is _on_ the treadle, the other is fixed _off_ its treadle, as shown
in Fig. 89. The consequence is that when the picking bowls come round
(there are two bowls on the bottom shaft at each side of the loom) the
loom will pick always from that side where the loose plate is _on_ the
treadle, and at the other side, where the plate is _off_, the bowls
will pass over the treadle without touching it. By moving the rod R
sideways, the plates may be moved alternately off and on their treadles.
[Illustration: FIG. 89.]
[Illustration: FIG. 90.]
If the loom has four boxes at each side, it may be necessary to pick
four times in succession from one side of the loom, and by a simple
arrangement the picking can be regulated at will. The mechanism
for moving the rod R sideways is shown at Fig. 90. Inside the loom
framework a lever, L, is centred at C, and by a combination of levers
is connected to the rod R, which is the rod referred to in the previous
diagrams. A strong spring keeps the plates right for picking from one
side, but when it is required to pick from the other the lever L is
lifted, which moves the rod R sideways and moves the plate off one
treadle and on the other. A chain is used for lifting the lever L, and
the star wheel A is turned by two pins on the wheel B on the bottom
shaft of the loom, or by one pin if on the crank shaft, thus causing
the star wheel to be turned one division every pick. The loom may thus
be made to pick four times from the right side, three from the left,
twice from the right, and so on, of course always taking care that the
shuttles are there to be picked.
CHAPTER IV
_DOBBIES_
The tappet shedding motion is the simplest and most perfect for a
small number of shafts. They may be made to work an indefinite number
of shafts, but it is seldom that above eight or ten are worked with
ordinary tappets, and about sixteen with Woodcroft’s or other plate
tappets.
With dobbies, a higher number of shafts may conveniently be worked, but
it is not only for this reason that dobbies are so extensively used.
They are extensively used for weaving twills, satins, and other simple
weaves, on four or five shafts. The chief advantage they possess is
that any number of shafts within their capacity may be used without
extra trouble or cost; whereas ordinary tappets have to be made
specially for each pattern; whilst section tappets, and oscillating
tappets, are inconvenient.
Dobbies are made to weave up to 40 or more shafts, but 16 and 20 are
the commonest numbers. Most dobbies now used are on the double-lift
principle; indeed, the single-lift dobby or witch machine is almost
obsolete in cotton weaving. The chief kind of double-lift dobby is the
“Hattersley” or “Keighley” dobby. The principle of this machine was
invented by Messrs. Hattersley & Hill, of Keighley, Yorkshire; hence
its name. Since the original patent rights have expired, almost all
loom makers have their own particular form of this dobby, embodying
many more or less minor improvements on the original. The principle
of this dobby will be understood from the lecture diagram, Fig. 91.
The dobby is placed at one side of the loom, and is therefore in
a convenient position for being attended to. The upright rod R is
connected to a crank on the bottom shaft of the loom, and therefore the
rocking lever AB, centred at C, will make one complete movement to and
fro, every two picks. The knives D and E slide along, always retaining
a horizontal position, one going inward as the other comes outward.
[Illustration: FIG. 91.]
The shaft or stave is connected to the jack lever FGH at F, and the
upright MN is fastened to this lever at H, the fulcrum being at G. The
upright MN has two hooks, P and Q, connected to it at opposite ends,
and suppose that when the knife D is in its innermost position, as in
the diagram, the hook P is dropped on to the knife; when the knife
begins to move it will take the top of the upright MN with it until MN
assumes the position indicated by the dotted line M′N, and the stave
is lifted. If it is required to lift the same stave for the succeeding
pick, the bottom hook is then dropped on to the knife E, which at that
moment will be in its innermost position just commencing its outward
movement, and is taken forward by it until the upright MN assumes the
position indicated by the dotted line MN′; and it will easily be seen
that as the top of the upright is moving back from M′ to M whilst the
bottom of the upright is moving forward from N to N′, the centre of
the upright H remains stationary at H′, with the exception of a slight
movement caused by the knife going further back than the hooks, and
thus the stave remains up all the time. The character of the shed is,
therefore, what is termed “open shed”--that is, if a stave is required
up for several picks in succession, when it is lifted it remains up
until it is required to come down again. This is what is meant by “open
shed” as compared with “centre shed,” the characteristic of which is
that the lifted stave, instead of remaining up, is let down halfway
every pick and taken up again if required.
The method of dropping the hooks is as follows:--Two levers, S, T, of
different shapes are employed for each pair of hooks; these levers
are centred on a rod, X. One of the levers, viz. T, is bent from the
fulcrum to touch the bottom hook, and the lever S projects straight out
from the fulcrum, and an upright needle O rests upon it, the top hook
resting upon the upright needle. When the lever SY is lifted a little
at Y it will drop the top hook, and when TY is lifted at Y it will drop
the bottom hook.
In a 16 shaft dobby the parts shown in the diagram are duplicated
sixteen times--that is, there are sixteen uprights MN, each with two
hooks, sixteen levers SY, sixteen like TY, and sixteen of other parts.
The levers SY and TY are operated by lags pegged so as to lift the
staves to give the required pattern. These lags work round a cylinder
or barrel, which is turned round the space of one lag every two picks
intermittently. Each lag operates the hooks for two picks, one row of
pegs operates the top hooks P, and the other row of pegs the bottom
hooks Q. The method of pegging the lags will be understood from Fig.
92, where two lags are shown with the pegging for a two and two twill.
Of course care must always be taken that the pegs are put opposite the
proper levers, as when only a portion of the jacks are used, say eight,
it is often preferred that the staves be connected to eight jacks in
the middle of the machine.
[Illustration: FIG. 92.]
[Illustration: FIG. 93.]
Dobbies constructed with single jacks, as indicated in Fig. 91, are
only suitable for narrow looms. Those constructed with double jacks
are preferable for wider looms, as they not only keep the healds under
better command, but they also move them in a perfectly vertical plane
without the tendency to a slight side movement such as occurs when the
healds are controlled by single jacks, in consequence of the ends of
these describing an arc of a circle as they rise and fall. One of the
best adaptations of double jacks to the Keighley type of dobby is that
exemplified in the “Climax” dobby made by Lupton and Place, Burnley.
This is represented in Fig. 93, in which A and B are complementary
jack-levers operated from the same baulk-lever, J, controlled by
hooks P and Q, to govern the same heald. The distinctive features
of this dobby are the construction of the outer jack-lever A in one
part, instead of two parts, and its attachment with the inner jack,
B, by means of a link, C. This modification is a great improvement on
double-jack dobbies in which the connections are made with streamer
hooks or rods, or those in which the jacks are geared by means of
toothed segments, as these increase the number of parts that are liable
to wear and to get out of order.
The Keighley dobby is decidedly the most popular one at the present
time, but what is known as the “Blackburn” dobby is preferred by some.
This is a double-lift dobby, which gives a centre shed--that is, the
staves which are required up for a number of picks in succession are
let down halfway every pick and taken up again. The principle of this
dobby is illustrated at Fig. 94. The staves are lifted by the two jacks
A and B; when B is lifted it causes A to lift the same distance. There
are two hooks, D and F, for each double jack, and the lags are divided
into two parts, all the odd numbered picks being fastened together, and
the even picks forming another chain. The pegs in the lags press back
the hooks, the back part of each of which forms a spring, so that when
the hook is pressed back it leaves the stave down.
[Illustration: FIG. 94.]
The knives lift alternately. When one is going up the other is going
down, and when one hook of a pair is lifted, as in the diagram, a lag
operates the other hook, and if the same stave has to be lifted for
the next pick, the hook is left over the knife, and the second hook
will be taken up whilst the stave is being let down, and will catch it
halfway and take it up to the top again. This is the advantage of all
double-lift machines over single-lift. The staves which are required
up for a certain pick are being taken up whilst those which were up
for the previous are coming down. A saving of time is thus effected,
and the looms can be run quicker than with single-lift machines. A
crank L on the end of the bottom, or picking, shaft is connected by
means of a lifting-rod E to the end of a horizontal arm M, mounted
on a shaft G, which constitutes a fulcrum for the arm. On one end of
shaft G, at the rear of the machine, there is fixed a toothed quadrant
H, which, through the medium of a small wheel, transmits motion to a
similar toothed quadrant H′ fixed on the end of a shaft G′; and each
quadrant is connected, by means of rods K and K′ to the rear ends of
the respective griffe-bars D and F. On the opposite ends of the shafts
G and G′, there are fixed, one on each shaft, two short arms which are
respectively connected to the fore ends of the griffe-bars. Therefore,
as the crank L revolves, the griffes are raised and depressed
alternately, and in a contrary manner.
Another thing to be borne in mind is that in a single-lift machine all
the staves come to the bottom every pick, and therefore the character
of the shed is different from that of a double-lift. In double-lift
machines there are the “open-shed” like the Keighley dobby, and the
“centre shed” like the Blackburn dobby. It is important to remember
these points, as the cover and appearance of the cloth is affected by
the beating-up being done in different kinds of sheds.
[Illustration: FIG. 95.]
The loom crank is usually set at the top centre, or thereabouts, when
the rising and falling staves are level, so that the shed will be
partly open for the next pick by the time the loom crank gets to the
front centre. In single-lift dobbies the beat-up is made when the shed
is closed, and so the warp has not the same chance of being spread
as with the timing of double-lift dobbies. This difference in the
character of the shed when the beat-up is made is caused by the fact
that in a double-lift machine the knives, being in the middle of their
stroke, are moving at their quickest speed when the shed is closed,
and in a single-lift the knife is almost stationary when the shed is
closed. The same thing occurs in Jacquards, and the matter may be
better understood by a reference to the chapter on Jacquards.
Dobbies can be made “positive” in various ways. Keighley dobbies are
made with a pin fixed on the upright MN (Fig. 91) at the point H. A
wire is hooked on to this pin and connected to an ~L~ lever at the
side of the loom opposite the dobby; this is connected to a lever at
the bottom of the loom. By connecting the bottom of one stave to this
lever the stave will be pulled down as the upright MN is taken forward,
and so the knife whilst taken one stave up is pulling another down,
rendering the dobby positive. This, of course, will only do for certain
simple patterns, such as twills, satins, and similar weaves, and would
not do for patterns where different numbers of staves are lifted every
pick. Positive dobbies are not much used in the cotton trade.
The ordinary form of dobby is non-positive, the stave being kept
down by springs in some form or other. One reason which may be urged
against ordinary springs, or “jack boxes,” is that the pull on the
heald increases as the stave is lifted and the spring opened. It is
obvious that this is just the reverse of what is required, as the stave
is lifted positively, and the pull on it may therefore conveniently
be decreased as it is lifted, and the healds would last longer. The
use of the spring is to keep the stave down, and therefore it should
exert its greatest force when the stave is at the bottom. A simple
method of accomplishing this has long been in use. Something on the
same principle has been used on hand looms for generations, and very
cheap and convenient undermotions of this kind have long been available
for power looms; but, strange to say, cotton manufacturers have been
very slow at adopting them. An undermotion of this kind is illustrated
at Fig. 96. The spring is fixed at A, and a wire hook connects the
spring with the quadrant at B. It will easily be seen that as the stave
lifts, the direction of the pull of the spring is gradually moved over
the centre of the quadrant at C. If the stave were lifted until the
spring was in a direct line from A to C, the pull on the stave would be
_nil_, as all the force would be exerted on the fulcrum. Each stave is
connected at both sides in the same manner, the springs and other parts
are all arranged in a very compact manner, and the cost is very small.
[Illustration: FIG. 96.]
Another form of undermotion on the same principle is much used in
Yorkshire in the woollen and worsted trades. This is illustrated at
Fig. 97, and is known as Kenyon’s undermotion. In this the springs are
arranged horizontally, and therefore longer springs can be used. The
quadrant is centred at C, and a strap is fast to the quadrant at D.
The spring is connected with the quadrant at F. The strap passes from
the quadrant under the bowl B, and then to the stave. Another quadrant
serves in the same manner for the opposite side. The spring is fastened
to a bar at E, and as the stave is lifted, the pull of the spring is
gradually moved over the centre C, and therefore the pull on the heald
gradually decreases as it is lifted.
[Illustration: FIG. 97.]
CHAPTER V
_MISCELLANEOUS_
When two or more pieces are woven in one width and afterwards cut or
torn apart, if there are not a few leno ends to divide each piece the
warp threads have nothing to stop them from coming out at the cut
sides. In light fabrics this is a greater disadvantage than in heavy
and finely picked ones, such as velvets, and therefore in the former
it is usual to weave a few ends leno to keep the edge firm. There are
various kinds of motions for effecting this object, one of the oldest
being that illustrated at Figs. 98 and 99. This is for an ordinary
plain loom, and the crossing end is taken through the back stave and
through a loop from the top of the front stave. This loop is often
formed of a small fine pliable chain, as it wears longer than worsted.
Fig. 98 shows the back stave lifted, and Fig. 99, the front stave
up, when it will be seen that the crossing end is brought up on the
opposite side from the previous pick.
[Illustration: FIG. 98.]
[Illustration: FIG. 99.]
[Illustration: FIG. 100.]
[Illustration: FIG. 101.]
Another, and perhaps a better, method, is Shorrock and Taylor’s patent,
shown at Figs. 100 and 101. For a plain loom the two straps A and B are
fastened to a drum on the top roller of the loom. In these straps are
the small eyes C and D, and through these eyes the crossing ends are
taken. The “standard” ends, round which C and D are crossed, are drawn
through the fixed eyes EF, immediately above the small bobbins MN.
The straps pass round the bobbins and up to the elastics X, which are
fastened to a hook, L, at the top of the loom. The top roller is rocked
to and fro by the ordinary staves, and when rocked in the direction
against the elastics the crossing threads are brought up inside as
shown at Fig. 100, and as the roller rocks back the elastics pull the
eyes C and D completely round the bobbins and take the crossing threads
up the other side of the “dummy” or “standard” ends, EF. The selvedge
formed is thus like that shown at Fig. 102.
[Illustration: FIG. 102.]
There are many patents taken out every year for split motions, but the
simple old forms still keep their place.
Another invention of a totally different kind may be mentioned. In
this, the weft is cut between the two cloths every pick as it is being
woven, and the loose end is then turned round and taken into the
cloth at the next pick, thus forming a practically perfect selvedge;
indeed, it would be impossible for any one to find out the difference
without being told or making a very close examination. For about half
an inch at the inner side of the cloth there are double picks, but
this is scarcely noticeable. The practical utility of this invention
is yet to be proved, and one thing to militate against its general
adoption is its cost, which is several pounds per loom, whereas some
of the ordinary split motions cost only a few shillings per loom. With
Jacquards or dobbies it is an easy matter to arrange an ordinary doup
heald to form a split, but the arrangements before mentioned are used
for plain looms, where it is not so easy to get the required lift. The
twist used must be very strong, as no slackener is used. Usually it is
a three-or four-or six-fold cotton thread.
[Illustration: FIG. 103.]
Another kind of selvedge motion is that used for producing a plain
selvedge on a loom weaving satteens with tappets. The fact of the
ordinary satteen being five picks to the round, and a plain selvedge
being a necessity, causes either the tappets to be made ten to the
round, working the plain selvedges by tappets on the same shaft, or
the selvedge ends must be worked from another shaft. In what is known
as Smalley’s satteen motion the former principle is acted upon: the
tappets are ten to the round, and the plain is worked from the same
shaft.
A more ordinary form is that shown at Fig. 103. A small tappet, A,
is fitted on the bottom shaft (or picking shaft), and this acts
upon a lever, B, to which the bottom of one set of harness threads
containing, say, the odd-numbered ends of the plain is connected, the
other, or even-numbered, ends of the plain being connected to the
elastic E, the bowl F at the top being used for working round. When
the tappet presses down the lever B, it will take half the plain ends
down and the other half up, and the elastic will pull back again as
the tappet allows it. In this way a plain selvedge is obtained in a
five-shaft satteen.
[Illustration: FIG. 104.]
Another method of effecting the same purpose is shown at Fig. 104.
A shaft A is placed under the loom, and this shaft is made to rock
to and fro to work the mails B and C alternately up and down. The
picking shaft of the loom has a crank M fastened to it, and a strap S
is taken from this crank to the small drum H on the shaft A, and is
wrapped round it. As the crank M revolves it will pull the shaft A in
one direction until the crank gets to the top, and when the crank has
passed the top of its stroke the spring X will pull the shaft back to
its original position, and thus the required reciprocating motion is
given to the shaft A and to the mails B and C.
_Double-beat Slay._
A double beat is sometimes required to be given to each pick of weft.
This is done in weaving some of the heaviest kinds of sackings,
carpets, and similar fabrics. Fig. 105 shows how this is effected. AB
is the slay, and is movable about B as a centre; EC is in two pieces,
viz. ED and DC, and these are fitted loosely on a pin at D. It will be
obvious that when the crank occupies either position QP or QP′, the
slay will be at the front of its stroke, and as the crank is moving
from P to M it will pull the slay back a little, and in moving from M
to P′ a second beat-up will be made. Whilst the crank is moving from
P′ to P the shuttle is passed through the shed. It is obvious that a
beat-up of this kind will enable the weft to be beaten well up into the
cloth, and more to be put in than with a single beat. The force exerted
is often so great that the looms have to be very firmly fastened into
the floor on which they stand, or they would move.
[Illustration: FIG. 105.]
CHAPTER VI
_JACQUARD WEAVING_
The Jacquard machine was the invention of a Frenchman of that name, who
exhibited the machine about the year 1800. It was introduced into this
country about twenty years later. The chief advantage of the machine
is that a large number of warp threads can be operated separately, and
a larger figure be produced than with a shaft harness. The chief ideas
in the machine are that each mail is connected separately to its hook,
and the use of perforated cards to leave any hook over the griffe if
it is required to be lifted, or to push it away from it if the hook is
required to be left down in the shed.
The original Jacquard machine was a single-lift, and although many
minor improvements have been made in it, the main features are
practically the same to-day as in the earliest machines introduced
into this country. At the present day the single-lift is comparatively
little used in cotton manufacture owing to the increased speed at
which double-lifts can be worked, but it is still preferred in silk
manufacture for several reasons. One reason is that the character
of the shed when beating up in a double-lift machine is essentially
different to that produced by a hand-loom, where of course a
single-lift is always used, and as hand-loom fabrics have a finer
touch and appearance than power-loom fabrics, the object is to imitate
the hand-loom production as nearly as possible. The cause of this
difference in the character of the shed when beating up will be
explained later in this chapter. Another reason is that silk-looms
could never be run at any speed higher than that of which a single-lift
machine is capable, and therefore the advantage of increased speed of
the double-lift is of no use.
Double-lifts, owing to the counterpoise and the division of the work
on to two knives, are undoubtedly steadier in working, and this is
an argument decidedly in their favour. Single-lifts are still used
in the manufacture of figured lenos, as no shaking motion has yet
been successfully adapted to enable the crossing ends to cross with a
double-lift machine.
[Illustration: FIG. 106.]
A single-lift Jacquard for weaving a pattern which occupies 400 ends
in a repeat consists of 400 hooks and 400 needles, with an extra row
of eight hooks for selvedges, or other auxiliary use. The hooks are
arranged in eight rows with 51 hooks in a row. A cross section of this
Jacquard is shown at Fig. 106, where the uprights are the hooks and the
horizontal wires the “needles.” A is the “needle board,” and this is
a perforated board through which the needles pass. The bottom needle
B is twisted or looped round the back hook D, and the connection of
the other needles and hooks is shown. At the back of each needle a
small spring made of fine brass or steel wire is placed. These springs
are held in position in the “spring-box” S. There are, therefore, 408
springs required for the 408 needles. The hooks rest on the grate G,
but in some makes of machine the grate is not used and the hooks rest
upon a “bottom board.” In this case the hooks are very liable to turn
round, and thus cause annoyance. To prevent this, flat hooks have
been used, and the needle loop was shaped so as not to permit the hook
to turn within it. The eight knives form the griffe. These knives are
all fastened together, and are moved up and down from the crank-shaft
of the loom. The illustration shows the knives at the bottom of their
stroke, and at this point, or immediately after the griffe begins to
move upwards, the card on the perforated cylinder E is pressed against
the needles, and if there is a hole in the card, the needle directly
opposite the hole will pass through it and into the perforation in the
cylinder, and the knife will take up the hook to which this needle is
connected. If the card is blank opposite any needle it will press back
the hook, and as the knife lifts, the hook is left down. Thus it is
possible to lift any of the 408 hooks in the machine for any pick. When
the cylinder is taken away from the needles the hooks are forced back
into their original position by the small springs in the spring-box S.
It will be noticed that the knives are leaning a little, and the reason
for this will be apparent, as if they were not leaning they would catch
the tops of the hooks in coming down, and would break or bend them. The
sloping position enables the knives in coming down to press back the
tops of the hooks and so get under them, ready for the next card to be
pressed against the needles. The knives should come down low enough to
be quite clear of the hooks, and therefore in this machine there is a
considerable dwell when the shed is closed.
The harness for a straight-over pattern is mounted as shown at Fig.
107. In order to prevent confusion the connection of the cords to
the machine is not shown, but the numbers on the line A represent
the hooks in the machine to which the cords are to be attached. The
“comber-board” or “cumber-board” B is a frame into which perforated
slips are fitted. These slips are perforated to different degrees of
fineness, the fineness being regulated by the number of ends per
inch required in the cloth to be woven. The lingoes, L, are metal
weights, and serve the purpose of keeping the mails down. MM are the
mails, through which the warp threads are drawn in the order shown
by the numbers, beginning at the back left-hand corner. The draft in
straight-over patterns is always taken in this way in Jacquard weaving,
although it is not compulsory. The harness is built with linen thread,
and the method of tieing the lingoes to the hooks will be understood
from the diagram.
[Illustration: FIG. 107.]
When one lingoe has been connected to each of (say) 400 hooks, the
first pattern is complete. Supposing there are 100 ends per inch, the
pattern will occupy 4 inches, and therefore if cloth is required 28
inches wide in the harness, there must be seven lingoes attached to
each hook, making seven patterns, or seven repeats of the pattern,
in the width of cloth. Thus when one lingoe has been tied to each
hook, beginning with the first and ending with the 400th, another is
connected to each hook, beginning again with the first; and when this
is done other patterns are formed in the same manner until the required
number is complete.
[Illustration: FIG. 108.]
It is important to have a clear understanding as to which is the hook
which lifts the first end in the draft. This hook is the one connected
with the bottom needle in the last row on the 25-side of the machine.
As we stated previously, a 400s machine has 400 hooks arranged in 50
rows of 8, or 8 rows of 50 hooks, and in addition there is always a
spare row of hooks, making 51 rows in all. As it is necessary to lace
the cards in the middle as well as at the sides, a space has to be
allowed for the lace holes, and therefore the machine is divided into
two parts by a space between the 26th and 27th rows.
A plan of a card is given at Fig. 108. The length of the card between
the two peg holes A and B is nearly 14½ inches, and the distance
between the centre of the top needles and the bottom needles is 1⅞
inch exactly. This holds good for all English-made machines, but the
American index is different.
It will be seen that there are 26 rows on the _right_ of the machine
and 25 rows on the _left_, and one is called the “26-side” and the
other the “25-side.” The cards are always numbered at the “26-side,”
and the cutting is commenced at this end. It may be as well to explain
here the order in which the holes are cut from the design, as it will
assist in following the point paper design to the loom. The cutting is
usually done in a “piano” cutting machine, which will be explained more
fully later on. By this machine one row of eight holes can be cut by
operating eight punches and pressing down the right-foot treadle of the
machine.
The number end of the card is gripped by the machine, and at the first
stroke of the right foot, the lace holes EF and the peg hole A are cut,
then one stroke of the treadle is made without cutting, and the pointer
of the machine arrives at the 1st or spare row. If the selvedges are
worked from this row, holes are cut accordingly. Then the pointer
comes to the 2nd row, and in this row the cutting from the design is
commenced.
At Fig. 109 the design is made on point paper, as it is required
to appear in the cloth right side up, with the twill in the ground
running in the same direction as shown on the design. When cutting, the
design is usually turned round, as shown at Fig. 110, and the cutting
commences from the top right-hand corner A. To show the matter clearly,
the first row of holes cut are numbered, both in the design and the
card, in consecutive order.
[Illustration: FIG. 109.]
[Illustration: FIG. 110.]
The first hole cut in the card is operated with the little finger of
the right hand. Following this hole to the loom, we find it operates
the _last_ or _400th_ end in the draft, and that the hole cut last on
the card (numbered 400) operates the first end in the draft. This
is the hole which operates the bottom needle in the last row on the
“25-side” of the Jacquard machine, which, as was previously stated, is
the hook from which the draft begins.
Following out the operation of cutting the card. When the 26th row has
been cut, the lace holes MN (Fig. 108) are cut, and then the cutting
is again straight-forward to the 50th row. The piano machine is so
constructed that with the same stroke of the treadle which cuts the
51st row the peg hole D is also cut, and then follows a stroke without
cutting, after which the two lace holes T and Y are cut. This makes 56
strokes of the foot for each card.
It is usual, in order to economise space, for the Jacquards with
straight, or “Norwich,” harnesses to be placed on the loom, so that
on one loom the cards hang over the weaver’s head, and on the next
the cards are at the back of the loom. In both cases the harnesses
are built the same way, but in one case (cards over weaver’s head)
the thread operated by the bottom needle on the “25-side” will be
at the back of the comber-board, at the left hand; and in the other
case (cards behind loom) the same thread will be at the front of the
comber-board at the right-hand side.
As previously stated, the single-lift Jacquard for cotton weaving is
not often employed except for special purposes, such as figured leno
weaving. The advantage possessed by the double-lift Jacquard as regards
speed is so very considerable that its adoption for ordinary forms of
cotton weaving has become universal; and the advantage of speed is not
the only advantage it possesses, as will be pointed out shortly.
A double-lift machine with one cylinder for a 400 end pattern consists
of 800 hooks and 400 needles. Each needle is twisted or bent round two
hooks, as shown at Fig. 111. The hooks are connected together in twos
by neck cords, which are usually strong whipcord, as will be seen from
the illustration. It will be seen that the bottom needle is bent round
the back pair of hooks, the next needle round another pair, and so on.
Each needle has a spring behind it, as in a single-lift machine.
[Illustration: FIG. 111.]
There are two griffes, which work oppositely--that is, as one goes up
the other comes down. The griffes (or knives) are worked by a double
crank on the bottom shaft of the loom, so that each griffe moves from
the bottom to top of its stroke in one pick, and from top to bottom in
another pick.
The principle of the double-lift will be understood from Fig. 112. One
knife, A, is at the top, and the other knife, B, is down. One hook of
the pair is lifted, and therefore the ends in the mails connected to
the neck cord at C will be lifted. Suppose now it is required to lift
the same ends of warp for the next pick: a card is pressed against the
needles, and if there is a hole in the card opposite the needle E, it
will leave the needle and the hook N where they are, and as the knife
B is lifted, the hook N will be taken up as the hook M is coming down.
The hooks will cross at about the middle of their stroke, and the
weight of the ends and lingoes on the cord C will at that moment pass
from the hook M to the hook N. In the diagram the cord attached to the
hook N is slack, but when this hook is lifted the cord will gradually
tauten until it bears all the weight, when the cord from the hook M
becomes slack. We thus have the ends for the second pick lifted whilst
the ends which were up for the previous pick are coming down. This is
where the advantage of the double lift lies. In a single lift the knife
must lift the hooks up and then come down to the bottom before another
card can operate the needles, whereas in a double lift the card for
a second pick can be brought against the needles as soon as the ends
which were up for the previous pick are ready to come down.
[Illustration: FIG. 112.]
It is obvious that in the position shown in Fig. 112, when one knife
is up and the other down and the needle pressed back by the card, that
the hook M will also be pressed back, as shown by the dotted line.
The bend of the hook over the knife, therefore, must be sufficient to
prevent the hook being pushed off the knife, and it will be noticed
that the hooks in this class of machine are bent more than the hooks
in a single-lift machine. The hooks rest on the grate G, Fig. 111, and
the shape of the hook at this point acts as a spring to straighten
the lifted hooks after the pressure of the card has been taken off
the needles. A machine of this kind can be run at a speed of about
160 or 170 picks a minute, as compared with the 130 or 140 picks of a
single-lift.
A double-lift machine on another principle is illustrated at Fig. 113.
This is a two-cylinder machine, and to weave a pattern repeating on 400
ends this machine requires 800 hooks and 800 needles. The cylinders
work at opposite sides. The hooks are placed as shown in the diagram,
the hooked parts facing each other in pairs, and by following carefully
the manner in which the needles are twisted round the hooks it will be
seen that there are really two single-lift machines placed together,
alternate rows of hooks representing each machine. There are two
griffes, as in the double-lift single-cylinder machine, and the griffes
are worked in the same manner.
[Illustration: FIG. 113.]
The cylinders work alternately, the cards being laced in two sets,
all the odd numbers being together in one set and the even numbers
forming another set. Immediately one knife is at the top and the other
at the bottom, one cylinder is pressed against the needles, and it
will be noticed that the hooks which each cylinder operates have the
hooked parts in the direction of the cylinder. When the hooks operated
by one cylinder are at the top the other cylinder is pressed against
the needles, and thus the work done by one cylinder in Fig. 111 is
divided between two in this machine. The advantage of this machine is
in the lessened speed of the cylinders. The vibration caused by the
cylinder working at a high speed in a single-cylinder machine is so
great that the limit is reached at about 170 picks per minute, whereas
a double-cylinder machine can be run up to 200 or sometimes even more
picks per minute, though perhaps 180 is a more advantageous speed. The
top set of needles project a little further through the needle board
to compensate for the difference in leverage on the hooks.
Besides the advantage of speed, double-lifts have an advantage in the
counterpoise obtained by one set of hooks going up as the other comes
down. This causes a more even motion and steadier working. Another
advantage possessed by double-lifts is that the beating up of the weft
is effected in a crossed shed, thus enabling more weft to be put in
than in a single-lift, where the beat-up is done with a closed shed.
This beating up in a crossed shed also spreads the warp better, and
prevents the reed marks from showing, for the same reason as was given
when referring to the spreading of the warp in the tappet loom.
In silk weaving a single-lift machine has an advantage in imitating
more closely hand-woven goods, as hand-loom weavers usually beat up in
a closed shed. This causes the weft to be put in straighter--that is,
less wavy, which is very desirable in silk fabrics.
The cause of this difference in the shed when beating up in the two
kinds of looms will be understood by following the relative positions
of the griffes and the loom crank throughout its revolution.
In a single lift the time allowed for opening and closing the shed must
be used to the best advantage; that is, as much time as possible must
be given for this purpose. On this account it is necessary to pick the
moment the slay is sufficiently far back to allow the shuttle to enter
the shed--that is, when the slay is half-way back, or the crank at the
bottom centre. The griffe is worked by a crank on the top shaft of the
loom, and there is no actual dwell of the griffe or of the ends when
the shed is open; therefore the shed must be opened a little wider than
would otherwise be necessary for allowing the shuttle to pass through.
The shed must be sufficiently open to allow the shuttle to enter when
the loom crank is at the bottom centre. This regulates the timing of
the other parts. Fig. 114 will make this quite plain. The shed must be
nearly fully open when the crank is at the bottom centre to allow the
shuttle to enter; and when the loom crank is at A the griffe must be
nearly at the top. When the crank is at B the griffe will be at the
extreme top, and when the crank is at the top centre, or C, the griffe
will be as near the bottom as it was to the top when the loom crank
was at A. As was previously pointed out, the griffe must go further
down than the hooks to allow another card to operate the needles, and
therefore it is when the loom crank has arrived at C that the knife is
leaving the hooks resting on the grate, or bottom board. The griffe
will be at the extreme bottom when the loom crank is at D, and when the
griffe is up at the hooks again the crank is at the front centre, or E.
Thus the shed has the fraction of a revolution between B and C to close
in, and between E and B for opening. The shed remains closed for the
quarter of a revolution, C to E.
[Illustration: FIG. 114.]
[Illustration: FIG. 115.]
In a double-lift the warp is much more leniently dealt with. As we have
said, the shed must be open for the shuttle to enter when the loom
crank is at the bottom centre. Therefore the griffes should be in their
extreme position--one up and one down--when the crank is at the bottom
centre.
The timing of the parts in a double-lift will be seen at Fig. 115. The
cranks that work the griffes are on the bottom shaft, which of course
makes a revolution every two picks. These cranks will be perpendicular
when the shed is fully open; therefore when the loom cranks are at
the bottom centre the cranks which drive the griffes must be in the
position AB. If they are so set they will be in the position CD when
the loom crank reaches the back centre, and in the position EF, or
horizontal, when the loom crank arrives at the top centre, when the
shed will be closed. We have thus a closed shed when the crank is at
the top centre, as in a single-lift; but in this case when the shed
is closed the griffes are moving quickly, whereas we have a quarter
of a revolution dwell after the loom crank reaches the top centre in
a single-lift. This causes, as we shall see, a difference in the shed
when the slay beats-up, or is at the front centre. When the griffe
cranks are in the position GH, the loom crank will be at the front
centre, and thus the shed will be partly opened for the next pick when
the reed comes in contact with the cloth.
Jacquards are made in various sizes. 100s, 200s, 300s, 400s, and 600s,
are the most common. 100s are arranged in rows of four; 200s and 400s
are in rows of eight; 300s and 600s in rows of twelve.
There are two distinct kind of harness mounting, the London and Norwich
systems. In the former the Jacquard is placed with the narrow end
towards the front of the loom, thus causing the cards to fall at the
side. In the Norwich system, or “tie,” the machine is placed with the
broad side facing the front of the loom, thus causing the cards to
hang either over the weaver’s head or at the back of the loom. On this
system, as there are eight rows in a machine, by taking the comber
board eight rows deep the harness becomes what is called a straight
neck. With the London system, the end of the machine facing the weaver,
there must be a twist in each pattern in the harness. There is not much
to choose between the two systems. Some prefer the London tie, as they
say the twist in the harness causes the harness threads to support
each other, and so last longer. The Norwich system is the more common,
especially in the cotton trade.
[Illustration: FIG. 116.]
Fig. 116 shows the method of tying up the harness on the Norwich system
for a bordered fabric, such as handkerchiefs. In these goods it is
usually preferred that both borders should point inwards, as in the
sketches Figs. 116 and 117.
[Illustration: Fig. 117.]
The hooks to which the harness threads are attached are numbered on
the line A, and it will be seen that the draft begins in the left-hand
corner at the back of the comber-board, the lingoes being numbered in
the order of the draft. The cords are tied up just as for an ordinary
straight-over harness for the first 400, or one full pattern of the
machine, but then, instead of commencing with the first hook again,
the 201st lingoe is tied to the 201st hook, and the second half of the
pattern is repeated. This forms the middle of the handkerchief, and it
must be repeated over a sufficient number of times to give the required
width of cloth after allowing for the trimming and border. In Figs.
116 and 117 nothing but a border and middle are shown, but sometimes
a trimming of another small weave is required outside the border, and
this, which is usually on a small number of hooks, is repeated over
in the same way as the middle. In Fig. 118 only two repeats of the
middle are shown; but supposing that the harness had 100 ends per
inch, and that the handkerchief was required to be twenty-four inches
wide excluding the border, there would be twelve repeats of the middle
required. When the middle has been repeated over a sufficient number
of times, the other border must be tied up, and to obtain the reverse
position of the figure the draft must be reversed. By tying the next
lingoe to the 200th hook, and going backwards with the draft, it can
easily be seen that the same figure will be woven at this side of the
harness as at the opposite side; the only difference will be that the
figure will point to the left, as will also the twill in the ground,
if it is a twill. This system of tying up is compulsory in the Norwich
system, as it is usual to keep the harness straight--that is, the
harness threads from each of the eight rows in the Jacquard each form
a separate row in the comber-board. We have thus eight rows in the
machine and eight rows deep in the comber-board, and it would not do to
have a thread taken from the front of the comber-board at one border
and from the back of the comber-board at the other border to the same
hook.
[Illustration: FIG. 118.]
If the harness is a “London tie” it necessitates a half-turn in each
pattern, as the machine is at right angles to the comber-board.
Therefore the draft may be continuous, as shown at Fig. 117, where,
after the middle has been repeated a sufficient number of times,
finishing with a thread from the 400th hook at the front of the
comber-board, the next one is taken from the 200th hook through the
back of the comber-board, and the border will finish with a thread from
the first hook going through a hole at the front of the board--just the
reverse to the other side.
Bordered goods are often made with two borders at each side, and
sometimes the borders are repeated a few times. The number of hooks
taken for the border and middle respectively vary according to
requirements. Sometimes, in a 400 machine, 300 will be taken for the
border and 100 for the middle, and so on. The cross-border must of
course be designed, and the cards cut. The number of cards in a set in
these goods is often very large, as the middle must be repeated over
the required number of times, and there will be as many cards used in
the set as there are picks in the handkerchief.
In designing for the mounting given at Fig. 117, the design would
be made on 400 ends: 200 for the border and 200 for the middle, and
the cards would be cut just in the ordinary manner. The cross-border
would also be designed in such a manner as to harmonize with the side
borders. The portion to be designed is enclosed by the dotted lines.
Centre ties or point ties are another class of harness in regular use.
This is really the two borders of a bordered harness joined together.
Fig. 118 shows how the tying up is done for a pattern of this kind. The
first 400 threads are connected as usual, the draft being from back to
front. When the 400th has been reached, the draft is reversed until
No. 1 is arrived at again. The same effect is obtained as in a point
of V draft in a shaft harness. The pattern must be of such a character
that one half is the exact reverse of the other. This kind of harness
is used for weaving large damask figures, and it is obvious that the
effect produced is really that of a figure on 800 ends, or twice the
size of the machine. Designs of this character are of course rather
stiff, but are suitable for damasks, and similar fabrics.
CROSS-BORDER JACQUARDS.
[Illustration: FIG. 119.]
The object of a cross-border Jacquard is to save the expense of cards
in handkerchiefs and other bordered goods. As pointed out previously,
the portion of the handkerchief between the two cross-borders is
usually repeated over for a considerable number of times, often from
twelve to twenty times. This often means using a few thousand cards,
which might be saved if the border and middle cards could be laced
separately and changed automatically. On the hand-loom it is usual for
the weaver to change the cards by hand when required, substituting the
border for the middle cards and _vice versâ_, but in the power-loom
this is of course out of the question, and usually the total number of
picks in the handkerchief have each a separate card. The cross-border
machine illustrated at Figs. 119 and 120 is the invention of Messrs.
Crossley and Davenport. The machine is double-lift, as will be seen
from the connection of the neck-cords. The border cards are put on one
cylinder, B, and the middle cards on another, A. When the cylinder
A presses back a needle, say the top needle C, it will press back
the pair of hooks EF, as in an ordinary double-lift single-cylinder
machine, and as long as this cylinder is worked every pick the machine
is to all intents and purposes a double-lift single-cylinder machine.
When this cylinder is stopped and the cylinder B is worked every pick,
the cards on the cylinder B have exactly the same effect on the ends
as those on cylinder A; for when the top needle in this set of needles
is pressed back, it will force backward the pair of hooks EF, exactly
as operating needle C by the other cylinder did. Only one spring-box
is used, as the upright wires MM pass through loops, P, in the long
needles, and small iron bars, HH, act as fulcra for the wires MM. The
tops of these wires are fastened to the short needles N, as indicated
in the diagram, and thus when the needle N is pressed back it moves the
needle C in the opposite direction and operates the hooks EF.
[Illustration: FIG. 120.]
The cylinders can be changed by pulling the cord L in Fig. 120. When
the parts are in the position shown in this illustration, the cylinder
A will be pressed against the needles every pick. The cylinders are
driven from the crank shaft, the rod X goes to the crank shaft, and a
reciprocating motion is given to the ~L~ lever CD centred at E.
The rocking lever FG is centred at K, and the reciprocating motion is
transferred from CD to FG. It will be seen that one end of the lever FG
is in the diagram inside the bend in the slot on M, and the other end
of the lever FG is in a position to move about its centre, K, without
moving the cylinder B. Thus as the crank shaft of the loom revolves
it will give motion to the cylinder A, but not to B. By pulling the
cord L, however, the bend on the slot on N takes hold of the top of
the rocking lever G, and at the same time, through the lever SR, M is
lifted, and the end F of the rocking lever moves freely in the slot
without moving the cylinder A. The disadvantage of this motion is that
the change is not made from the cards automatically, certainly not an
impossible piece of mechanism to contrive. There are other cross-border
motions, but this is only given as an example.
DOUBLE-SHED JACQUARD.
Double-shed Jacquards are used chiefly in weaving heavy goods where a
very large and deep shuttle is required to hold a reasonable quantity
of weft. The principle of this machine will be easily understood from
Fig. 121. A is connected to the crank shaft of the loom and moves the
end of the lever BC up and down, the fulcrum of the lever being at E.
The bottom board or plate F is therefore moved up and down, and in
doing so the griffe G is made to move oppositely, the bottom plate
coming down as the griffe goes up, and _vice versâ_. This is effected
by the top levers PR and QS, which are centred at O. One end of the
griffe is connected to Q, the other end of the griffe is connected to
P. This gives firmness and strength to the machine. These Jacquards are
usually made very heavy, as they are chiefly for heavy work.
[Illustration: FIG. 121.]
Only a few hooks are shown as an example, but the machines can be made
any size. When all the hooks are resting on the bottom board, which
will be when the bottom plate is at the top of its stroke, the card is
pressed against the needles and selects the hooks to be lifted in the
usual manner, after which the griffe rises as the bottom board sinks.
Thus an extra deep shed is produced without the griffe having so far
to lift as would otherwise be the case. The shed produced is a centre
shed, all the ends coming to the centre every pick.
“OPEN-SHED” JACQUARD.
Several open-shed Jacquards have been patented. That of Wilkinson’s is
illustrated at Figs. 122 and 123. A and B are a pair of hooks, which
are connected by a cord passing round a pulley, W. This pulley works
on a pin at one end of the thin plate C, and at the other end of the
plate is another pulley, X. The neck cord E passes round this pulley
to the bar D, to which it is fastened. It is obvious that when one hook
of the pair is lifted, say, 4 inches, and the other is at the bottom,
the pulley W will be lifted 2 inches; and as the cord E is fast to D,
the harness threads will be lifted 4 inches, the same as the hook.
[Illustration: FIG. 122.]
[Illustration: FIG. 123.]
If one hook of the pair is lifted and it is required to keep the same
ends of warp up for the next picks, the hooks being connected round
the pulley W, one hook going up as the other comes down will keep
the harness cords stationary, and the hooks A and B can be lifted
alternately one up, one down, without moving the cord E, which will all
the time be keeping the warp ends up. The shed thus obtained is similar
to that in a Keighley dobby; the ends, when once they are lifted, stay
in that position until they are required to come down. The principle
can be applied to either double-lift single-cylinder or double-lift
double-cylinder machines.
Another view of the pulleys is shown at Fig. 123, where the pulleys and
other parts are lettered as in the previous figure. Each pair of hooks
in the machine has these pulleys attached, and therefore it will be
understood that the pulleys must be rather thin in order to enable them
to be placed in a space equal to the size of the Jacquard machine. The
advantage which a satisfactory machine on this principle would possess
lies in the fact that the jerk which occurs in ordinary double-lifts
when the weight is passing from one hook to another in each pair is
done away with. This jerk causes breakage of the neck cords, and many
efforts to overcome the annoyance have been made. This principle of
open shed may be applied to dobbies such as the Blackburn dobby.
THE SPLIT HARNESS.
[Illustration: FIG. 124.]
The split harness is an ingenious method of increasing the size of
pattern which can be woven on a given Jacquard. What is termed a
“double-scale” split harness consists of two adjacent lingoes being
connected to each hook in the machine. Thus with a 400s machine there
are 800 mails in a pattern. A few lingoes are shown at Fig. 124 tied up
in the manner of a double-scale harness. The connections to four hooks
are shown. Underneath the comber-board a loop is made in the harness
thread, and shafts SS, either wood or metal, are inserted through the
loops in each row in the harness. These shafts are worked by the spare
hooks in the machine, and in the places where the ends are left down by
the Jacquard, the shafts, being lifted to a given ground pattern, will
weave the ends singly. In Fig. 124 the shafts are shown lifted to weave
a plain or tabby ground, every alternate one being lifted. Hooks No. 1
and No. 2 are lifted by the Jacquard, and hooks 3 and 4 are left down,
and it will be seen that where the hooks are down, half the ends will
be lifted by the shafts. The ends, when lifted by the Jacquard, cannot
be woven separately with this harness, and therefore the bindings in
the figure will show in twos, which, unless the harness is a fine one,
has a tendency to make the cloth appear coarse. Satin or twill grounds
may be woven. In fact, the ends left down by the Jacquard may be woven
singly to any pattern which repeats on the number of shafts used, or
into the number of rows which the harness is deep in the comber-board.
Of course either the figure or the ground may be woven singly,
according to the way the pattern is designed, but not both.
In silk weaving, harnesses are built on this principle to a threefold
scale--that is, with three mails attached to each hook--and as in the
double-scale a figure repeating on 800 ends can be woven on a 400s
machine, so with a threefold scale a 1200 figure can be woven on a 400s
machine. In this case the bindings in the figure will be in threes, but
the ground ends may be woven quite singly by the shafts.
This principle is only adapted for very fine reeds in cotton goods, but
is often used in silk manufacture, where 300 or 400 threads per inch
are not uncommon.
THE PRESSURE HARNESS.
The pressure harness was invented with the object of enabling very
large figures to be woven on ordinary sized Jacquard machines. In very
fine silk damasks--say, with about 400 threads per inch--a very large
machine (or machines) is necessary to obtain a figure suitable for
damask on the ordinary principle. The pressure harness overcomes this
difficulty in a most ingenious manner.
[Illustration: FIG. 125.]
The method originally used consisted in drawing a number of ends in
each mail, and then drawing each end separately through a shaft in
front of the harness. These shafts had long eyes, as shown in Fig. 125;
in fact, the eyes are large enough to permit of the shed being opened
without their interfering with it. In Fig. 125 two of the Jacquard
lingoes are shown, A, representing those lifted by the Jacquard, and
B, those left down. There may be any number of ends in each mail, say
five. After being drawn through the Jacquard harness in fives, the ends
are drawn singly through the shaft harness in front. These shafts are
either worked by treadles or by a Jacquard. In the diagram they are
shown worked in the latter manner. A small pulley is placed between the
hooks and the shafts, and each shaft is connected to two hooks, a cord
from one hook passing round the pulley to the other hook. When both
hooks are lifted, the shaft will be lifted to the top, like the shaft
1; when only one hook of the pair is lifted, the shaft will be taken
up half way, like the shafts Nos. 2, 4, and 5; and when both hooks are
left down, the shaft is left at the bottom, like the shaft No. 3 in the
diagram. These shafts require to be worked by a machine with double
the lift of the Jacquard machine behind them, as from bottom to top
the lift is twice the size of the shed. They may also be worked on the
centre shed principle, one shaft going up and another one going down
from the centre each pick.
If one of these shafts is lifted to the top, like shaft No. 1, it is
obvious that it will take up one end out of every mail left down, and
by lifting the shafts in satin order the ends left down by the Jacquard
in fives would be woven singly five shaft satin. By leaving one shaft
down every pick, the ends lifted by the Jacquard will be split up in
the same manner. So that with one shaft at the top, one at the bottom,
and the other three lifted half way, a figure repeating on 2000 ends
can be woven on a 400s Jacquard, every end being woven singly in both
the ground and the figure. Of course only simple weaves can be used,
and the figure will move in steps round the edges. If it is required
to weave an eight shaft weft satin figure on an eight shaft warp satin
ground, eight shafts must be used instead of five. The ends may still
remain five in a mail, as it is not necessary that the number of ends
in each mail should be the same as the number of shafts used. These
shafts are called pressure healds; hence the name given to the harness.
In designing for this class of harness the figure is put on point paper
in simple colour, no binding dots being used, as the binding is all
done by the pressure healds. The method of putting down the plan for
lifting the healds, and of devising a variety of weaves for pressure
harness weaving, will be found fully explained in Chapter X.
[Illustration: FIG. 126.]
Another and better kind of pressure harness is illustrated at Fig. 126.
Instead of healds with long eyes, two sets without eyes are used, but
with a simple clasp in the middle. Fig. 126 shows the mounting for a
five end satin figure on a five end satin ground, and two lingoes only
of the Jacquard are shown, O representing the lifted hooks, and P the
hooks left down.
[Illustration: FIG. 127.]
There may be five, six, eight, or more ends in each mail, and they
are drawn singly into the pressure healds in front in the following
manner:--There are two sets of healds with clasps, as shown at Fig.
127. Each end is drawn singly _over_ a clasp in the set A, and _under_
a clasp in the set B. The clasps in the set A are fixed at the bottom
of the shed, and the clasps in B are fixed at the top of the shed. By
pulling one of the set B down and lifting one of the set A every pick
in satin order, the ends lifted in fives or sixes are woven singly in
warp satin, and the ends left down in fives or sixes are woven singly
in weft satin.
[Illustration: FIG. 128.]
The method of operating the pressure healds in a hand loom is shown
at Fig. 128. The shafts in set B are pulled down by lifting the end E
of the levers EF, and the same on the other side. The shafts in the
set A are lifted directly by the hooks. The shafts are lifted by a few
spare hooks in the Jacquard. Sometimes the Jacquards have three or
four rows of extra hooks for this purpose, and these hooks are placed
a little to one end of the machine, and a small separate cylinder is
used. The cards for lifting or pulling the pressure healds are put on
this cylinder, and the large cylinder carrying the figure cards is
only turned round once every few picks by arranging the catches to
do this. The same card is thus brought against the needles several
times in succession, and the smaller cylinder being turned every pick,
interweaves the threads in satin or the required order. This will form
steps at the edges of the figure in the weft way as well as warp way,
and is a considerable saving of cards. The weights M are to pull the
healds B up, and the weights N to keep the healds A down. Springs may
be used in their place, but weights are preferred in the hand loom.
The mails used in the Jacquard harness are made with a separate hole
for each end. Sometimes as many as twelve or sixteen ends are drawn in
each mail, thus giving in the latter case a 6400 end figure from a 400s
machine, so that with 300 ends per inch the figure would measure over
20 inches wide.
EDLESTON HARNESS.
A method of weaving an 800 figure on a 400 double-lift machine has
been patented by James Edleston, of Preston. This is a very useful and
ingenious idea, as a floated figure can be formed, and the machine
remains a double-lift, with all its advantages as regards speed.
Certain limits are placed upon the weaves, which can be employed for
the ground or for developing the figure, but sufficient scope is
afforded for all practical purposes to make the invention a success.
An illustration is given of this harness at Fig. 129. The inventor
gives no drawing in his specification, but presumably the illustration
(Fig. 129) will represent his method; at least, it will effect the
same object. One row of hooks of a 400s double-lift single-cylinder
machine are shown, and it will be noticed that the hooks are not joined
together by a neck cord as in the ordinary machine, but the harness
threads are taken singly from each hook as in a single-lift machine.
The knives work as in a double-lift, one up, one down. By cutting the
cards in a certain manner the whole of the 800 hooks may be operated
by the 400 needles so as to produce ordinary brocade or damask figures
with a repeat of 800 ends. The same end cannot be lifted for two
picks in succession, as the knives have to move up and down and work
oppositely; but an end can be _left down_ any _odd_ number of picks,
and a figure can thus be formed. At Fig. 130 the design for eight-end
satin ground is given. It must be remembered that for eight ends there
are only four needles, and therefore the lifting dots must be put on
four ends on the point paper. By carefully comparing this design with
the mounting of the harness, the principle will be quite clear. The
design shows a dot on the first and fifth ends on the first pick, and
therefore a hole will be cut in the card opposite the first and fifth
needles.
[Illustration: FIG. 129.]
Suppose the griffe A to be lifted for the first pick, it will lift the
first and ninth ends. The second card has holes opposite the second and
sixth needles, and when the griffe B is lifted for the second pick, it
will lift the fourth and twelfth ends in the warp or lingoes in the
comber-board. The third card has holes opposite the fourth and eighth
needles, and as on the odd picks the griffe A lifts, it will lift the
seventh and fifteenth ends in the warp. If this is followed out it will
be found that the ends are lifted in the order 1 4, 7 2, 5 8, 3 6, or
eight end satin is woven. Fig. 131 shows the method of putting the dots
on point paper for four end twill (one and three). The principle is the
same as in the preceding case, and is very simple when understood. A
hole opposite the first needle on the first pick causes the first end
to be lifted, and a hole opposite the same needle for the second pick
causes the second end to be lifted. Any figure can be put upon the
cloth, with the following limits as regards the bindings: firstly, an
end cannot be lifted for two successive picks; secondly, every end must
be left down an odd number of picks.
[Illustration: FIG. 130.]
[Illustration: FIG. 131.]
From this it will be seen that a five end satin cannot be woven, nor
can a weft figure be put on a warp ground. Plain grounds can be woven,
and cord grounds of various kinds are also suitable for the harness.
DAMASK OR TWILLING JACQUARDS.
These Jacquards are now extensively used for weaving linen, damasks,
and similar fabrics, and are used where pressure harnesses were
formerly used. The pressure harness puts a great strain on the warp,
and requires a longer distance between the cloth and the warp beam than
is usually allowed for in power looms; therefore much ingenuity has
been expended on these Jacquards with the view of obtaining a large
design without using several ordinary Jacquards above each loom, with
the accompanying great expense in cards and other attachments.
The principle of damask attachments and twilling Jacquards is entirely
different to the principle of the pressure harness, and for fine silk
fabrics which require a very large extent of pattern and woven on the
hand loom, the pressure harness on the principle shown at Fig. 126 is
not likely to be replaced.
[Illustration: FIG. 132.]
[Illustration: FIG. 133.]
In the pressure harness a number of warp threads are placed in each
mail, the number of threads varying from five to sixteen; but in the
twilling Jacquard only one end is drawn in each mail, and a separate
hook is required for every end. The advantage comes in making each
needle serve for several hooks and in making one card serve for several
picks. One of the first inventors of this kind of Jacquard was Mr.
Barcroft, of Newry, Ireland, and it has been improved since by him and
others. The principle is illustrated at Figs. 132 and 133. There may
be any number of hooks to each needle. In the illustration there are
three. The machine is necessarily a single-lift, the griffe goes up
and down every pick. Only two needles are shown, operating six hooks.
When the top needle is pressed back it will press back the hooks 1, 2,
and 3, and when the bottom needle is pressed back it will press back
the hooks 4, 5, and 6. These hooks are bent at the bottom as in the
diagram, and a bar or rod A is passed through each row of hooks the
full length of the machine. These bars A are lifted by the twilling
hooks, shown in the diagram in dotted line. These hooks are placed at
the sides of the machine: two hooks for each long row of the ordinary
hooks, or one for each end of every bar, A. The blades of the griffe
are movable about the centres EE, and at each end of the blades and
immediately behind each twilling hook (dotted) there is a projecting
piece, P, also shown in a dotted line in the diagram.
Now, when the griffe is at the bottom, the blades are operated by a
pegged barrel, and by turning the blades one at a time out of the way
of the hooks as the blade M is turned, it is obvious that a whole row
of hooks can be left down which would otherwise be lifted.
Turning the blade has also another effect. On the front of the blade at
each end, as previously pointed out, is a projecting piece, P, and when
the blade is turned, this projection pushes the twilling hook in front
of it (dotted) on to the next blade of the griffe, and the twilling
hook is lifted. The bottom of the twilling hook is fastened to the end
of a bar, A, and the bar is lifted, thus lifting a whole row of hooks
which would otherwise be left down. In this manner it is obvious that
by operating the blades of the griffe in regular order, the figure can
be woven warp twill and the ground weft twill, or _vice versâ_. At Fig.
133 the position of the six hooks is shown after the griffe is lifted.
It will be seen that the blank opposite the top needle pressed the
first, second, and third hooks back, and they would all three have been
left down but for the bar A being lifted. The hole opposite the bottom
needle leaves the fourth, fifth, and sixth hooks over the griffe, and
they would all have been lifted but for the blade M being turned, which
also caused the bar A to be lifted. It will be obvious that the twill
must repeat on the number of bars A, or on the number of rows of hooks,
in the machine, exactly as in a split harness the ground weave must
repeat on the number of shafts or rods used under the comber board. In
these machines, as in the pressure harness, the same card is pressed
against the needles two, three, or more times in succession, so as to
give a great extent of pattern with a small number of cards. The number
of times a card is pressed against the needles depends on the number
of hooks there are to each needle, and on the relative amount of warp
and weft in the fabric. If there are three hooks to a needle and the
same number of picks as ends per inch, the card should be used three
times in succession, but sometimes there are more picks per inch than
ends, in which case each card should be used oftener; and sometimes, as
in silk damasks, there are 400 or more warp threads per inch and 100
picks, and supposing there were eight threads in a mail, it would make
a step of eight ends in the warp; therefore, to make the steps in the
weft balance it would be necessary to bring the same card against the
needles only twice in succession.
Fig. 134 is another arrangement for weaving damask. It is called
a damask attachment, and was patented by Tschorner and Wein. Its
construction differs from ordinary twilling Jacquards, but the
principle is much the same.
Each needle is twisted round several hooks, and the knives are operated
separately by cams at the side of the machine. The illustration shows
one of the knives left down, leaving down a row of hooks which would
in the ordinary course have been lifted, and one of the bottom lifters
is taking up a row of hooks which would in the ordinary course have
been left down.
[Illustration: FIG. 134.]
The foregoing are the chief kinds of Jacquards and harnesses (except
lenos) attached thereto, but there are many combinations of shaft and
Jacquard or mail harness which need not be mentioned in a book of this
size. We may mention a system, sometimes called half harness, in which
only half the ends are drawn through the Jacquard harness, and the
other half through shafts in front or behind. A double-sized figure may
thus be formed.
CHAPTER VII
_LENO WEAVING_
The word “leno” has latterly become a general term given to all classes
of cross weaving. Originally it had a different meaning to gauze, but
the word is now often applied to gauze as well as other fabrics woven
with doups. A pure gauze fabric is one in which the crossing thread
is brought up on one side of a standard end, and up the other side of
the standard end on the next pick. Fig. 135 shows how the threads are
interlaced in gauze weaving. It will be seen that the weave repeats
every two picks. The crossing end, and the end round which it crosses,
must be placed in one dent, and if an end is made to cross round a
number of ends they must all be in the same dent or split in the reed,
as it is very obvious that an end cannot be made to cross into another
dent with the ordinary doup heald.
[Illustration: FIG. 135.]
[Illustration: FIG. 136.]
[Illustration: FIG. 137.]
The end is made to cross from one side to the other by means of a doup
heald. These healds consist of an ordinary heald with an extra half,
generally called a “loose half” or slip. The method of knitting the
doup heald will be understood from Fig. 136. It is obvious that when
the doup is lifted at A, the end contained in the doup will be lifted
up on the right-hand side of the end E. In order to bring the same end
up on the left-hand side of E, the ends are drawn through the healds,
as shown at Fig. 137. There are two ordinary staves, and the ends are
drawn through them as for plain cloth with two staves. Then the end
which is drawn through the first stave is crossed under the end which
is drawn through the second stave, and is then drawn through the doup
in the manner shown at Fig. 136. When the doup is lifted it will lift
the crossing end A up on the right-hand side of the standard end B;
but in order to do this easily the end must be slackened. This is done
by taking all the crossing ends A from the warp beam over a slackening
rod or vibrator, R; the other ends of the warp B are taken over the
back rest in the ordinary manner. The slackener is usually in the form
of a lever, one end of which can be lifted by the dobby or whatever
shedding motion is used, and when the dobby lifts one end of the lever
the rod is moved downward, thus slackening the warp which is drawn
over the rod. Whenever the doup is lifted the crossing warp must be
slackened, or it would cause the standard end B to be lifted, as it is
crossed under it. In this manner when the doup is lifted the doup end
is brought up on the right of the end B. In order to bring the same
end up on the left of B, it is necessary to lift the first stave and
the loose half of the doup. The first stave naturally takes the end up
on the left-hand side of B, but it is necessary to lift the loose half
in order to let the end go up on that side. It is usual to show the
doup by a double line in the draft, the front line always representing
the loose half. The pegging plan or lifting plan for the healds is for
leno fabrics not usually shown on point paper, although it may be, just
as easily as any other way. The usual way is to rule horizontal lines
representing the staves and perpendicular lines representing the picks,
and to put a ~/~ on the shafts to be lifted for each pick. It is
easy to do this by continuing the lines which represent the shaft in
the draft, and to make the pegging plan on the same lines by the side
of the draft, as in Fig. 137. The two perpendicular lines one and two
represent the picks, and the marks on the first pick are on the loose
half, the doup, and the slackener; therefore all these will have to be
lifted. (It is usual to peg the dobby to lift the loose half along with
the doup to take the strain off the healds.) On the second pick the
marks are on the loose half and the first stave, therefore these must
be lifted for the second pick.
With the same draft as in Fig. 137, a considerable variety of patterns
can be made of a style known as crossover lenos. This style consists in
weaving a number of picks plain, and then making a cross with the end.
At Fig. 138 the design draft and pegging plan are given for a “five
and one” crossover leno. From the design it will be seen that the doup
is required to be lifted for the first pick, and the first stave and
loose half for the second pick, the second stave for the third pick,
and so on. This lifting is shown in the pegging plan at the right of
the draft, where on the first pick marks are put on the doup and loose
half the slackener, and on the second pick on the loose half and first
stave, and so on. There are in this pattern six picks to the round. The
appearance of the cloth will be a bar of five picks plain, and then a
crank or open space, in the middle of which is a single pick; the crack
is caused by the crossing of the ends.
[Illustration: FIG. 138.]
In gauzes and fabrics of this description, a thin open fabric in which
the ends will not fray or slide is the object. The nature of the weave
enables a firmer fabric to be obtained with a smaller number of ends
and picks per inch than in ordinary weaving where the threads are not
crossed.
[Illustration: FIG. 139.]
[Illustration: FIG. 140.]
Another and quite distinct effect is produced with doups. This is
commonly called “lace” or net, and is often combined with gauze or
other “open” leno effect in stripes known as “lace and leno stripes.”
This lace effect is produced by making a thick end form a zigzag on the
plain ground. The interlacing of the threads in a simple lace or net
stripe is shown at Fig. 139. A thick end, A, is brought up first on
one side and then on the other side of two plain or nearly plain ends,
B and C. There are ten picks to the round, and by the side of this
dent there is another thick end twisting in the opposite direction,
first up one side, and then up the other of two more plain or nearly
plain ends. Each thick end comes up for two picks at one side and then
crosses under and comes up on the other side after an interval of three
picks, and _vice versâ_. The marks represent the ends lifted. By the
side of the lace there are two plain ends shown, which represent the
unlimited number of ends used for the ground of the fabric. In weaving
this pattern the draft and pegging given at Fig. 140 would be used.
By carefully following the design with the draft and pegging plan the
principle will be easily mastered. The arrangement of the shafts is
rather important. The doup is placed in front, the ground staves next,
and the leno or net staves next. It is immaterial whether the crossing
ends be taken through the first stave of the three used for the leno,
or the back one--some prefer one way, some another--but it is necessary
to get the leno staves as far back as possible to give the thread a
better chance of crossing. Four staves are taken for the plain, as
in ordinary weaving, to prevent overcrowding. The lifting marks on
the pegging plan will be easily followed if the one in Fig. 138 was
understood. Where the fifth stave is lifted the loose half is lifted
also, and both thick threads come up on the inside. Where the doup is
lifted the slackener is lifted also, and the ends are brought up on the
outside as on the sixth and seventh picks. More will be said on the
arrangement of shafts in the chapter dealing with designs for leno. The
explanations on the structure of the fabrics at this point are only for
the purpose of enabling the requirements of the looms for weaving them
to be understood. Some manufacturers prefer to work with the doups at
the top of the loom, especially in weaving net lenos. In this case the
crossing end is crossed over the others and slipped downwards.
It used to be considered that gauze and lenos could not be woven
on double-lift machines. In other places than Lancashire this idea
prevails to-day to a great extent, but of course this is a great
mistake. The simpler kinds of lenos, such as pure gauze and crossovers,
are sometimes woven on tappets, which are, of course, double-lift.
The tappets are of the ordinary kind, drawn on the same principle as
described earlier in this book; but the tappet which operates the
standard ends is made to lift the staves halfway when the doup end
is crossing. Tappets of this kind have been used for some time past,
and it is not surprising that the same principle should be applied
to double-lift dobbies. Instead of drawing the tappets to lift the
standard ends half way or a little way to enable the ends to cross
easier, the easing motion usually employed for dobbies is often used,
and the tappets are of the ordinary kind.
In a double-lift dobby the healds begin to lift for one pick when the
healds which are up for the previous pick begin to come down. In the
case of Fig. 137, when the doup is lifted for the first pick and begins
to come down, the same end is being taken up the other side of B by the
stave No. 1 being lifted. If the end B were not moved it would very
soon be broken by the crossing end being made to act in this saw-like
manner upon it. It is necessary, therefore, to lift the end B about
halfway up at the moment the crossing end begins to come down and to
pass to the other side of B. If the end A has not to cross for the
next pick, it would not be necessary to lift the end B at all. In a
single-lift machine the doup will get to the bottom before the first
stave begins to rise, and therefore there would be no difficulty in the
end crossing. In a double-lift dobby the staves containing the ends
round which the doup thread crosses are lifted partly up every pick by
a lever worked from the crank arm of the loom. This easing motion or
“shaker” is shown at Fig. 141. AB is the crank-arm, and the upright
CD is connected to the crank-arm at C, and to a lever ED at D. EG is
another lever on the rod E, and the healds which are to be lifted half
way are connected to this lever at G, as well as to the jacks in the
dobby. As the crank revolves the oscillation of the crank arm imparts a
similar movement to the lever ED, and to the staves which are connected
to EG. This motion commences just at the proper time. Of course, when
the crank-arm is lifting the healds, the cords connecting these healds
to the dobby will be slack, as indicated at Fig. 141. By thus lifting
the standard healds, the crossing is greatly facilitated.
[Illustration: FIG. 141.]
This easing motion is not required where there is no crossing of the
end immediately, as, for instance, in Fig. 139, the doup end after
being brought up on one side is never required up on the other side
on the pick immediately succeeding, therefore the end has time to get
down before being lifted on the other side and an easing motion is not
required.
[Illustration: FIG. 142.]
The method of slackening the warp when the doup lifts is shown at Fig.
142. This diagram shows a two-doup arrangement. For gauze and similar
weaves it is not necessary to have a separate beam for the crossing
warp, as one end pulls the other and the take-up is about the same; but
for net lenos or laces after the manner of the fabric in Fig. 139 it is
necessary to have the crossing ends on a separate beam, as a great deal
more in length of this warp is required than for the plain. Sometimes
several beams are used, the only limit being the number which can be
placed in a given space.
At Fig. 142 the crossing warp from the bottom beam is taken over the
slackening rod A, and over the carrier E. The crossing warp from the
top beam is taken under the slackening rod B. A moves about a centre D,
and B moves about a centre C.
The slackener B is connected to a jack in the dobby by the cord L, and
the slackener A is connected to another jack by the cord M. When either
L or M is lifted, the warp over its rod will be slackened.
FULL CROSS LENO.
[Illustration: FIG. 143.]
A full cross may be made by taking the doup completely round the
standard end, as in Fig. 143, and alternately lifting the doup and the
other end. This is a much more difficult weave than ordinary leno, and
is not much used, although it gives a very pleasing effect when woven
with thick yarns. The weave repeats on two picks as in gauze, but it
is necessary to use very strong twist in order to bear the strain and
friction unavoidable in this crossing.
THE LENO JACQUARD.
[Illustration: FIG. 144.]
Where figures are required to be thrown up on a leno ground a Jacquard
mounting is required. It is possible to weave a plain figure on a gauze
ground with an ordinary Jacquard harness and an ordinary doup stave
in front, but this can only be done on a pure gauze ground--that is,
one end crossing one. A plain figure on a ground of this kind does not
afford a sufficiently powerful contrast to the ground. It is necessary
in order to produce a really efficient contrast to have two ends
crossing two and weaving separately in the plain. A fabric of this kind
is one of the most beautiful of all fabrics, and is remarkably cheap
and serviceable in wear. The method of producing a plain figure on a
gauze ground with one doup in front of any ordinary Jacquard harness
is illustrated at Fig. 144. The ends are drawn through the Jacquard as
usual, and are then taken in pairs and one crossed under the other, the
crossing end being taken through the doup, as shown in the diagram. The
crossing end in each pair is marked A. We can now see how either plain
or gauze can be woven at will. The doup is lifted for the first pick,
and this brings all the ends A up at the right hand side of ends B (see
first pick). In the first two dents the ends A are lifted again by the
harness, and the loose half of the doup being lifted will enable the
ends A to cross to the left side of the ends B. The doup is lifted for
the third pick, and it is obvious that this will weave gauze with the
first two dents. After the doup is lifted, if the end B is lifted on
the next pick, it will cause plain to be woven, as will be seen from
the diagram, where the third and fourth dents are weaving plain when
the first and second dents are weaving gauze, and _vice versâ_.
[Illustration: FIG. 145.]
[Illustration: FIG. 146.]
A proper leno harness is illustrated at Fig. 145. It is obviously
impossible with the arrangement given at Fig. 144 to weave a leno
with two ends crossing two in conjunction with plain, as there would
require to be two ends in each eye in the doup, and as the doup is
lifted every other pick, it is impossible to change to plain from the
leno. To obtain a figured leno of this description, each dent must have
a doup to itself, and the doups must be lifted by the hooks. At Fig.
145 the arrangement of the harness is shown. The machine is a single
lift, and in order to obtain a 400 end figure 600 hooks are required.
These are arranged in twelve rows, the two front rows being used for
the doup harness, the two back rows for the slackening harness, and the
eight middle rows for the ground or figure harness. For the 600 hooks
only 500 needles are used, the doup hook and its slackening hook being
connected with the same needle. The top and bottom needles are used for
the doups and slackeners, as shown in the diagram, and the eight middle
rows of needles for the ground or figure harness. The method of drawing
the warp through the harness is shown at Fig. 146. The two crossing
ends are drawn through the slackening harness, and all the ends are
drawn through the ground harness. It is immaterial whether the draft is
from back to front or front to back; some manufacturers of these goods
draw the ends from front to back. Of course, this must be borne in
mind in designing and cutting the cards. After being drawn through the
ground harness the two crossing ends are crossed under the other two
and drawn through a doup. The mails in the doup lingoes are specially
made to allow the thread from the slip to pass through and back again.
The shaft A (Fig. 145) is the slip or loose half, and serves for all
the doups. The mails in the slackening harness are placed, lower down
than the other warp, and these mails hang between two rods, B and C,
which are called the “bridge.” Sometimes only one rod is used, and this
serves equally well.
A better shed is formed by only lifting the slackening hooks half as
much as the other hooks, and therefore a special device is required for
giving only half the lift to these hooks. In the illustration, Fig.
145, there are two griffes, E and H, and the griffe E is connected to
the lever GK at a point, O, about midway between the fulcrum G and
the point where the griffe H is connected to the lever. The fulcrum G
is movable in a slot made for that purpose, so that the lift of E can
be altered a little if desired. When the griffe H is lifted in the
ordinary manner, it is obvious that the griffe E will only be lifted
about half way.
[Illustration: FIG. 147.]
The usual method of obtaining the half-lift, which this invention is
intended to supplant, is illustrated at Fig. 147. This method was
invented by the late Mr. Tootal Broadhurst, and has been in regular use
a long time. Each of the slackening hooks lifts a lever CP, centred at
C, the slackening harness is tied to these levers about midway between
C and P, and thus the mails are lifted only about half as much as the
hooks. Of course, in this case all the hooks in the machine are lifted
by one griffe, and therefore the slackening hooks are lifted as far as
the others.
This method serves its purpose very well, but if any alteration is
required in the lift of the slackening harness all the levers have to
be gone through and altered separately, whereas in the Devoge machine
the lift can be regulated to a nicety by moving the fulcrum G and the
point O. The slackening harness should be placed from nine inches to a
foot behind the ground harness.
The wire M, in Fig. 145, is for lifting the shaft A, which is required
to be lifted every pick. The advantage of using only one needle for the
doup and slackening hooks is that it prevents the possibility of the
slackener being missed when the doup lifts, as well as being a saving
in cards.
By lifting the crossing ends with the ground harness for two or more
picks, followed by lifting the same ends in the doup harness for a
similar number of picks, an open leno fabric is produced, and a plain
figure can be woven by lifting the ground harness plain, or a floated
figure can be formed exactly as with an ordinary Jacquard.
[Illustration: FIG. 148.]
[Illustration: FIG. 149.]
The usual method of putting the design on point paper for these
Jacquards is illustrated at Fig. 148. In the plan eight ends of leno
are shown with four picks in a shed; and eight ends of plain, of which
the figure is usually formed, are shown. The design on point paper
for this would be as given in Fig. 149. Ordinary 8 × 8 paper is used,
although there are ten rows of needles. The card-cutter cuts the black
squares opposite the ground harness needle, and where the circles come,
he cuts so as to lift the doup in the next dent. Thus in the first
four cards for Fig. 149, the card-cutter would cut opposite the third
and fourth needles in the ground harness, and opposite the doup needle
for the next four ends. The plain would be cut in the ordinary manner
opposite the ground harness needles. A larger design for this harness
will be found in Chapter X.
Double-lift Jacquards are not yet used beyond the experimental form, as
the shaking cannot be done as easily as in a dobby with shafts, but we
have heard of the thing being done by knotting the harness above the
comber board and lifting the board a little when the cross is being
made. Messrs. Eccles, of Preston, some years ago obtained a patent for
lifting the standard ends by means of a third knife or griffe. The
additional knife was given half the lift of the other two, and its
function was to lift the standard ends half way when the doup ends were
crossing to the other side. This would, no doubt, enable the cross to
be made with ease in a double-lift Jacquard, but the principle is not
likely to be a great success.
The doups in leno Jacquards are very liable to wear out unless made
of very good material, and some experience is necessary before the
harnesses are worked satisfactorily.
An imitation of the fabric usually woven on this harness is sometimes
made by making one end cross three ends in the leno, and weave plain in
the figure. This can be done with an ordinary harness with a doup heald
in front lifted every other pick, on the same principle as in Fig. 144.
CHAPTER VIII
_TERRY LOOMS--CARD CUTTING--LAPPETS_
[Illustration: FIG. 150.]
Terry looms are extensively used in the cotton trade, chiefly for
weaving towels, but often for striped dress and similar fabrics where
terry or loop pile is combined with other weaves. The loops can be
formed either on one side or both sides of the fabric, but the loop
formed in these looms is not to be compared with real loop pile woven
over wires, as the loops cannot be formed with the same regularity.
There are numerous terry motions, as they are called, most loom makers
having their own speciality. Fig. 150 is the design for a good terry
cloth. It will be noticed that the second and fourth ends are the
reverse of each other: one is up for four picks and down for one, and
the other is down for four picks and up for one, whilst the other two
ends are nearly plain. The first and third ends form the ground, and
the second and fourth ends the pile or loops. There are five picks to
the round.
[Illustration: FIG. 151.]
[Illustration: FIG. 152.]
The ground warp is on a separate beam to the pile warp, the latter
having a special tension to let off the required quantity to form the
pile. At the second pick in the pattern, just where the pile warp is
bound, the reed is made to beat further up than on the two preceding
picks, thus forming a pile by sending one half the pile ends to the
face and the other half to the back. The reed beats up to the front
for the second, third, and fourth picks in the pattern, as given at
Fig. 150, following which the reed is held back for two picks. Fig.
151 is a good motion for making the reed occupy the two positions when
beating up. P represents the slay, and a lever, A, centred at D, is so
constructed that when A is pulled down the reed is pushed forward. The
rod R is connected to a lever, M, on a shaft, N, placed under the loom.
A rocking motion is given to this shaft by a box cam, P, five to the
round (Fig. 152), so shaped as to lift and depress the lever QS for the
required number of picks. This cam is driven from the picking shaft.
By pulling the rod R downwards the reed is moved forwards, and the rod
will have to be kept down for three picks and moved up for two picks,
so as to keep the reed in its front position for three picks and a
little way back for two. The effect required is really to lengthen the
crank-arm at will, and the principle of the knuckle joint may be used
in its simplest form--that is, by having the crank-arm jointed in the
middle and fixed a little out of a straight line, and by straightening
the arm when the front position of the slay is required.
The real loop pile is woven over wires. The wires can be inserted and
pulled out automatically by a power-loom, but the richest kind of pile
is woven on the hand-loom. The structure of the fabric is shown at Fig.
153. The pile end is brought up over a wire every two picks, and when
the wire is pulled out the loops form a springy pile, which can be
made to give beautiful effects in dress goods. The principle is also
used in Brussels carpets, and similar goods. Where figured fabrics are
required on this principle, it is necessary to have each pile end on a
separate bobbin and weighted separately at the back of the loom, as the
take-up of each end would vary so much in the figure.
[Illustration: FIG. 153.]
[Illustration: FIG. 154.]
With cut pile the wires are either grooved, as at Fig. 154, or each
wire has a knife at the end, as at Fig. 155, and when the wire is
pulled out it cuts the pile. The best pile is formed by the grooved
wires, as the cutting wires are apt to drag the pile. When cut pile is
being made, about four or five wires are constantly in the cloth, for,
if the wire were pulled out immediately, the pile ends would fall away
from the cloth.
[Illustration: FIG. 155.]
[Illustration: FIG. 156.]
Looms are made to weave two pieces of plush (which is a long cut pile,
rather longer than velvet pile) in one loom simultaneously, one piece
above the other, after the manner shown at Fig. 156. The principle is
not used in cotton manufactures, although it has been tried. It is
chiefly used for silk plush.
CARD CUTTING.
[Illustration: FIG. 157.]
The cards are usually cut from the design on a machine called a
“piano” card-cutter. This machine consists of a punch-box (Fig. 157),
containing thirteen punches, twelve for cutting the smaller holes and
one for cutting the peg holes in the cards. There are eight “keys”
behind the punch-box, each of which has a small spring round it to
spring it back to its original position when the finger is taken off
it. These eight keys are used for cutting the eight rows of holes in a
400’s card, and for 600’s cards, with twelve rows of holes, the four
punches in front are used. The two punches in front at the right hand
are operated by the thumb on that hand, and the eleventh and twelfth
are operated by the thumb on the left hand. The eight keys behind are
governed by the four fingers on each hand. Fig. 158 shows the effect
of pushing in one of the keys. The key is pushed over the punch K, and
as an up-and-down motion is given to the whole punch-box by means of
two treadles operated by the card-cutter’s feet, the punches that are
locked will cut holes in the card. Where the keys are not pressed (see
Fig. 159) they do not act upon the punches, and the card is left blank
accordingly.
The card is clipped at the numbered end by a clip on the “carriage.”
This carriage recedes with the card for a space of one row of holes
every time the left treadle is pressed down. The method of cutting the
cards has already been explained with Figs. 108-110.
[Illustration: FIG. 158.]
[Illustration: FIG. 159.]
If several sets of cards of the same pattern are required, a repeating
machine is used. In the hand repeater the cards are made to leave
punches in a plate where there are holes in the card, and the plate
is then taken to a repeating press, where any number of cards can be
cut like the first by applying pressure to the plate, which is done by
passing it under a roller or wheel.
Some repeating machines are capable of repeating direct from one
set of cards to the other, at the rate of thirty or forty cards per
minute. The cards may be laced blank, and kept in stock ready for use
when required, which is a great advantage. The machine is built on
the Jacquard principle, and the punches required to cut are fastened,
whilst those which are not required to cut are taken out of the way of
the card.
These machines are rather costly, but in large fancy weaving
establishments they soon repay their cost.
LAPPETS.
[Illustration: FIG. 160.]
Lappet figures are formed by giving a horizontal motion to a thick end,
and making it interweave in the manner shown at Fig. 160. The system
has long been used in hand-looms, and it is now extensively used in
power-looms, especially in Scotland. The figures are usually produced
with a very thick end upon a fine muslin ground, and the advantage it
possesses over figuring with extra weft is that the figuring material
does not require cutting off every pick, and therefore there is not the
same amount of waste, and in addition the figures are more firmly bound
into the cloth.
Only small solid spot figures can be woven, as the figuring thread
cannot be bound between the extreme edges of the figure. This is the
chief disadvantage of the principle, and it is not to be compared with
swivels for the purpose of producing intricate designs. In swivel
weaving each figuring thread is placed in a small shuttle, which
receives a horizontal motion by means of a rack. The small shuttles
can be lifted out of, and dropped into, the warp, so as to allow the
figuring thread to be passed through the shed where the spot is formed,
and therefore twill or satin, and shaded effects, can be formed in the
spot. In lappet weaving the floats cannot be bound in the middle.
The chief advantage of lappet weaving is that it can easily and
satisfactorily be applied to a power-loom. Swivels have been applied
to power-looms, but not yet with entirely satisfactory results, taking
into consideration the question of cost.
The principle of the lappet power-loom will be understood from Fig.
161. In front of the slay cap the needle rack A is placed, the ends
resting in the slots BB, and this is moved downwards by the hook C
being lifted by the treadle F at the side of the loom. The figuring
threads are taken from a separate beam through the needles in the rack,
and it will thus be seen that when the rack is pulled down the figuring
threads will be at the bottom of the shed. When the treadle F is forced
down, the springs PP pull the rack back to its topmost position, and
when in this position the rack is pulled to the left by pressing down
the treadle D, the distance which the rack can be moved being regulated
by the size of the groove in the lappet wheel at that point.
[Illustration: FIG. 161.]
The lappet wheel G is a wheel with ratchet teeth, and is turned one
tooth at a time. The groove in the wheel is so shaped that the rack can
be pulled sideways a greater or a less distance as desired, to form a
spot or figure. The pin N fits in the groove, and when the treadle D is
pressed down the rack is pulled to the left as far as the groove will
allow, when the spring S gives way until the treadle reaches the bottom
of its stroke. When the treadle is released the spring K pulls back the
rack and treadle as far as the groove in the wheel will allow it. The
spring K is much weaker than S, so that when the treadle D is pressed
down the spring K gives way the first.
The needle rack being in front of the ordinary reed, a “false” reed
is required to guide the shuttle across the shed. This false reed M
is placed immediately behind the shuttle race, and it is lifted every
pick when the shuttle is going across, and dropped to make room for the
proper reed to beat up. The treadle E is used for operating the false
reed; the connection is shown in the diagram, and when the treadle is
pressed down the reed is lifted.
At Fig. 162 a section is given showing how the needle rack receives a
lateral as well as a perpendicular motion. The slay-cap is cut square,
and the cover C works loosely upon it. The needle rack A is pulled
down against the spring S, and the cover is pulled sideways by the bar
attached to the cover at O, carrying the needle rack along with it.
[Illustration: FIG. 162.]
[Illustration: FIG. 163.]
The treadles are operated by tappets, and those operating treadles E
and F must do so every pick, whilst the treadle D only requires to
be pressed down once every two picks, because the spring K pulls the
needle rack to the right. The tappets are shown at Fig. 163, where it
will be seen that when the treadle E is down, F is up, and the rack
will be dropped and the false reed lifted; and when the treadle F is
pressed down--letting the rack be pulled up by the springs, the treadle
D is pressed down, which pulls the rack to the left as far as the
groove in the wheel will allow it to move.
[Illustration: FIG. 164.]
[Illustration: FIG. 165.]
At the back of the lappet wheel a face cam L (Fig. 164) acts upon a
lever, MN, centred at P, and the bent arm of the lever N pushes the
hook C on to the treadle F when the spot figure is being formed, and
when there is no figuring going on the hook is pulled out of the way of
the treadle, and so the motion of the rack is stopped.
The pattern is formed by the groove in the lappet wheel (Fig. 165), and
in drawing this the wheel is divided into as many teeth as there are
picks in the pattern. The wheel is usually made of hard wood, and after
being smoothed off a number of circles are described, the distance
between each being equal to one dent in the reed. Suppose the pattern
is a continuous one, as at Fig. 166, the picks shown on paper being in
addition to the ground picks. In drawing a wheel for this pattern the
number of teeth required will be twenty-four, as there are this number
of picks in the pattern.
[Illustration: FIG. 166.]
The pattern extends to seven dents, and as the pin N (Fig. 165)
occupies four dents, it will be necessary to have eleven spaces, each
equal to a dent, in the groove. The first pick in the pattern floats
over two dents or four ends, and therefore the groove at this point
must be six spaces wide--four for the pin, and two for the space it
has to move through. Before the next movement of the rack, the wheel
will have been turned one tooth, and at this point the groove moves one
space further to the left. For the third pick both sides of the groove
are moved one space to the left, and the size of the float will remain
the same as in the second pick, but it will float over different ends.
The groove gradually gets wider until the tenth pick is reached, when
it narrows down again until it repeats on the twenty-fourth pick.
If there are two spots set “one and one” in the pattern, the wheel
requires one tooth more than the picks in a repeat, in consequence of
changing from one spot to the other.
CHAPTER IX
_AUTOMATIC WEFT-REPLENISHING DEVICES_
The history of the development of the power-loom, from its inception
by Dr. Cartwright, has been written on many occasions. That story
relates how old methods have been improved or else displaced by new
ones of greater efficiency, and how the modern power-loom has, by the
effort and skill of the pioneers of industry, been brought gradually
to its present state of mechanical perfection. This march of progress
goes on steadily, continuously, and almost imperceptibly to those who
are not immediately interested in or affected by the changes that are
thus wrought; until by some special circumstance they suddenly and
unexpectedly arrest attention, and it is realized for the first time
that a new era has dawned and promises changes of great magnitude.
The advent, now fifteen years ago, of what are popularly described
as “automatic looms” marked the beginning of events of considerable
importance to the weaving industry in particular, and to the textile
industry in general. The essential element which distinguishes these
looms from those of ordinary construction consists of special apparatus
attached to, and forming an integral part of, the looms, which are
thereby enabled to replenish weft automatically from a reserved supply
conveniently held in readiness. This briefly constitutes the automatic
element of the looms. There are, of course, many auxiliary attachments
that are incidental to the weft-replenishing devices, and which
increase their efficiency and productiveness.
Notwithstanding the comparatively short period that has elapsed since
the adoption, on a commercial scale, of these looms, such has been the
activity of inventors and loom-makers both at home and abroad, that
looms of this class have already been designed in an almost endless
variety of forms, some of which differ essentially in construction
and operation, whilst many others differ only in minor details of
construction. Most of these, however, have never matured to practical
forms. Many have never escaped the secret confines of the experimenting
room. Others have been doomed to premature failure, whilst some three
or four types of real merit are struggling hard for supremacy. Which
of the competing types will win, ultimately, is at the present time
matter for conjecture. This will depend entirely on the type that will
best meet the requirements of manufacturers, and the one that will
endure the test of experience and time, which alone can be the deciding
factors. But, for certain classes of fabrics for which they are
suitable, it is safe to predict that automatic looms of some approved
type are permanently established in the trade.
Whatever particular character these weft-replenishing devices assume,
they may be broadly classified under one or other of two distinct
types, namely, (1) that in which the same common shuttle is replenished
with cops or bobbins of weft; and (2) that in which a fresh shuttle
replaces the previous one. Each of these two broad divisions comprises
numerous modifications in both their construction and also in the
manner in which they operate.
Of the cop-or bobbin-changing type of loom, the “Northrop” loom,
invented in Hopedale, Mass., U.S.A., by James H. Northrop (a native of
Keighley, Yorks.), has gained a greater measure of success than that
of any other automatic loom; and of the shuttle-changing type, the
“Hattersley” loom, invented by Simeon Jackson, of Geo. Hattersley and
Sons, Limited, Keighley, Yorks., has probably found greater favour than
others of that type. Looms of the Northrop type require essentially
the use of shuttles of special construction that are capable of
self-threading the weft; whereas looms of the Hattersley type may
weave with the same kind of shuttles as those employed in ordinary
power-looms. Looms of both types are constructed so that the change
of weft is effected instantaneously whilst they are running at full
speed, without any loss of time; but when a change of weft takes place
in the Hattersley modification of the shuttle-changing type, the looms
stop running automatically for a few picks to allow more time for the
changing of shuttles, after which the looms re-start automatically and
continue running at full speed.
In addition to the essential elements constituting a successful
weft-replenishing device, this requires to be supplemented by numerous
appliances of a special character to ensure the general efficiency
of the loom. For example, at that side of the loom on which the
replenishment of weft is made, there is fixed a weft-cutting device
to sever the superfluous trail of weft close to the selvedge of
cloth after the insertion of each fresh supply of weft. In some
looms the weft is replenished only when the previous supply fails
either by breaking or becoming exhausted; and some are furnished with
“weft-feeler” motions to put the weft-changing mechanism into operation
and thus replenish the weft just before the previous supply is entirely
depleted, thereby preventing broken or missing picks of weft which
would produce faulty cloth. A warp-stop motion, which is sometimes
applied to ordinary looms, is an almost indispensable accessory to an
automatic loom. Its function is to detect the breakage of warp-ends,
and to stop the loom automatically whenever that occurs. These remarks
apply also to the controlling of the tension and delivery of the warp,
which are sometimes effected automatically in looms of any description.
Up to the present time weft-replenishing devices are almost exclusively
restricted to single-box looms employed in the production of standard
varieties of fabrics of comparatively simple construction, and
containing but one kind of weft requiring the use of only one shuttle.
These devices have, however, been employed on check-looms weaving
with more than one kind of weft, and therefore requiring the use of
a corresponding number of shuttles at the same time; but automatic
check-looms have not yet passed the experimental stage and become
established on a commercial basis, although there are prospects of this
taking effect in the near future.
Having thus far introduced the reader to what constitutes the chief
elements of an automatic or self-acting loom, it will, at this stage,
and before examining the details of their special mechanism, be both
instructive and profitable to briefly survey the work of pioneers in
this sphere of invention, as revealed in the records of the numerous
Letters Patent that have from time to time been granted for inventions
of devices for the automatic replenishing of weft in looms, and to
trace the origin and development of such devices from the earliest
authentically recorded date of their inception down to the present time.
From a research of the earliest published records of patents relating
to weaving, which records date from 15th July, =1620=, it would appear
that the credit for the first patent for an automatic weft-replenishing
device for looms is due to Messrs. John Paterson Reid and Thomas
Johnson, both of Glasgow, who are the joint patentees of an invention
of such a device described in the Patent Specification, dated 20th
March, =1834=, No. 6579. This is a large document of 69 pages of text
comprising over 35,000 words and 12 sheets of diagrams. It describes in
a very lucid manner several improvements in power-looms, of which that
relating to the automatic replenishing of weft is treated almost as if
it were regarded, by the inventors, as of only secondary importance to
the other improvements which they describe.
In view of the great progress which has been made within recent years
in the development of these looms, and also in consideration of the
fact that a patent, which was granted to Charles Parker nearly seven
years subsequently, and is described in the Specification dated
22nd October, =1840=, No. 8664, has been frequently cited as the
first patent relating to the automatic supply of weft in looms, the
first-named document acquires a special interest, not only as a record
of what is probably the first attempt in that direction, but also
because it establishes, beyond refutation, the date and rightful title
to the first patent granted for such an invention.
In the former specification, the patentees state that their
improvements are applicable to what were then known as Johnson’s
vertical power-looms, in which the warps were extended vertically
from the warp-beam at the bottom to the cloth-roller at the top of
the loom; and the reed, which served as the shuttle-race during the
flight of the shuttle through the warp-shed, moved in a vertical plane
when beating up the weft. These vertical looms were made double, to
permit of two pieces of cloth being woven in them at the same time;
but they had evidently been discarded, and were not then in use
amongst manufacturers. The looms made according to Reid and Johnson’s
specification were so very different from Johnson’s looms as to have
very little in common with them excepting that they also were vertical
power-looms in which the warps extended vertically. The specification
states that the “great object” of their improvements is to enable
=four= webs or pieces of cloth to be woven simultaneously and at
one operation in the same loom, with only one slay which has a vertical
motion, and also that the warps for the four webs are to be wound
on two separate warp-beams. After describing in minute detail the
construction of the improved loom, the patentees proceed to describe
their invention of a device for the =automatic supply of weft to
their looms whilst these continue running=. This part of their
invention is introduced as if it were quite incidental and of little
consequence, and is described as the “accessories and new improvements”
which they apply to their vertical power-looms, as follows:--
“In order to avoid stopping the motion of the loom when any one of the
=four= weft threads break, twice or three times as many shuttles as
are required for constant use are to be lodged in suitable receptacles
or shuttle boxes, which are so arranged that the =breaking of a weft
thread will cause a change of shuttles, and a substitution of spare
shuttles, which have been provided and placed in the said receptacles
ready for such changing=; for instance, the breaking or failure of a
weft thread from either of the two shuttles, which work on the same
reed as one pair, will cause the pair to be removed, and a pair of
spare shuttles to be brought into their place instantaneously, without
any act of the person who attends the loom, and who will therefore
have no occasion to stop the motion thereof when a weft thread breaks
or runs off, but will only have to take care to keep the loom at all
times provided with a sufficient number of spare shuttles ready filled
and inserted into their proper places in the receptacles, leaving it
to the machinery of the loom to remove those shuttles which have been
working, and to substitute others the instant that a change becomes
necessary in consequence of the breakage or failure of weft thread.
But if, by neglect of the attendant, the loom is not so provided with
a pair of spare shuttles ready filled and placed in preparation for
changing as aforesaid by the machinery on the breakage or failure of
any weft thread, then the loom will stop its own motion, wherefore the
weaving cannot be continued unless all the four webs have their several
wefts duly inserted in a proper manner for working cloth.” From this
description it is of interest to note that what probably constituted
the first automatic loom was of the shuttle-changing type, to which
nearly all subsequent inventors in this particular field have chiefly
devoted their attention.
It was not until an interval of nearly seven years had elapsed after
Reid and Johnson’s patent that a patent was granted to Charles
Parker, of Darlington, for the second invention of an automatic
weft-replenishing device, which, like its predecessor, was also one of
the shuttle-changing type. This device, along with other improvements
in power-looms, is described and illustrated in the specification dated
22nd October, =1840=, No. 8664, in which the fourth claim made by the
patentee is in respect of “means of changing the shuttle when the weft
is broken or the shuttle is empty of weft” without the necessity of
stopping the loom for that purpose.
The next and third patent for an automatic weft-replenishing device,
which, like the two previous devices, was a shuttle-changer, was
that granted to an agent, William Newton, to whom the invention was
communicated from a foreign country not named in the specification
which is dated 28th April, =1852=, No. 14,092. This document states
that the invention relates to improvements in looms for weaving plain,
figured, or fancy fabrics, and that it consists in the employment of
several shuttles arranged in the loom in such a manner that if the
weft failed, or the shuttle missed or flew out of the shuttle-box, a
second shuttle would always be in readiness to take its place, without
it being necessary to stop the loom in order to replace it with a
fresh shuttle. In carrying out the improvement, several shuttles where
placed one above the other in a box, or in guides fixed immediately
above the shuttle-race or box, and held in their place by means of
a stud, plate, or catch, which, when required, was removed so as to
allow a second shuttle to enter the shuttle-box in place of the spent
shuttle, which, by the same motion, was pushed out. In the event of
a shuttle flying out or missing the shuttle-box, the same mechanism
caused a fresh shuttle to supply its place. The special mechanism which
affected the changing of shuttles was put into operation by means of a
weft-stopping device which detected the absence of weft whenever this
failed to pass along the shuttle-race in front of the reed.
After an interval of five years from the granting of the previous
patent, Patrick McFarlane, of Perth, patented an automatic
weft-replenishing device which marks a distinctly new departure from
the previous inventions for the same object, and one, moreover,
which has the distinction of constituting the prototype of cop-or
bobbin-changing devices, of which type a modification has been so
successfully adopted in the construction of Northrop automatic looms.
McFarlane’s invention is described in the Patent Specification dated
13th April, =1857=, No. 1046, which states that “the first part of the
invention consists in means or arrangements by which a loom is made
to supply its shuttle or shuttles with fresh weft when the weft last
placed in the shuttle or shuttles has become broken or exhausted.” The
cop or bobbin of weft was placed in a case which fitted inside the
shuttle in which it was held securely during weaving, but from which it
could be easily ejected and replaced by another weft-case containing a
fresh supply of weft whilst the loom continued weaving. Any practicable
number of these weft-cases were conveniently stored and retained in a
suitable receptacle or hopper, so that the successive weft-cases could
take the place of those removed, as they were each in turn inserted in
the shuttle. The chamber containing the reserve supply of weft-cases
was attached to the framing of the loom opposite the shuttle-box or
boxes, so that when the absence of weft was detected by the weft-fork,
this put into operation the weft-changing mechanism which forced a
weft-case from the hopper into the shuttle, and thereby displaced the
previous weft-case which fell into a box or basket.
An interval of only three years elapsed before the next patent was
granted for a weft-replenishing device patented by Thomas Ingram, of
Bradford, for which the specification is dated 4th April, =1860=, No.
861. In this specification, the patentee describes a device which
combines the elements of both a shuttle-changing and also a cop-or
bobbin-changing loom. The invention relates to mechanism for effecting
a continuous action in looms without stopping them to change the
bobbins or cops, or for an additional supply of weft, whether that is
all used up or only broken. This was effected by forming an opening
or aperture in the front, back, top or bottom of the shuttle-box
“large enough to admit a shuttle, or a case containing a spool or
spools of weft, to pass through to be inserted within the box.” Also,
“when the weft is broken or used up, or a change of weft is required,
the shuttle, or the case within the shuttle containing the weft, is
immediately expelled through one of the openings in the shuttle-box,
and supplied through another of the openings with another shuttle or a
case containing a further supply of weft.” The patentee states later
that he is aware of a patent for a previous device “to exchange the cop
of weft by means of a portable case, whilst the loom was in action,”
and does not claim that device as a part of his own invention; but what
he claims “is the combination and the general arrangement of apparatus
or mechanism for producing or effecting continuous action in looms for
weaving.”
A device of a different character from any of those previously
described was one that formed the subject of a communication from
Julius Boeddinghaus, of Elberfeld, Prussia, to an agent, William
Brookes, and is described in the specification dated 14th November,
=1860=, No. 2787. The function of this device was merely that of
=ejecting= the shuttle automatically when the weft failed; but the
replenishing of weft required to be performed by hand in the usual
manner. The ejecting of the shuttle was effected by causing it to shoot
downward through an opening in the base of the shuttle-box at one end
of the slay, and on the occurrence of which the loom would stop.
A patent for the next device which, although not strictly belonging to
the present category of inventions, is, nevertheless, closely allied to
them, was that granted to John Leeming, Bradford, and described in the
specification dated 5th February, =1861=, No. 301. The specific object
of this device was to effect changes of weft of different kinds or
colours for the production of check fabrics. Weft-cases, as introduced
by Patrick McFarlane in =1857=, were employed to contain the weft,
and the weft-cases were exchanged automatically in the =same shuttle=
according to a prearranged scheme of decoration, but not on the failure
of weft, in which event the loom would stop as usual. The device was,
therefore, a checking motion to effect changes of different kinds of
weft by changing cops or bobbins, instead of employing a number of
separate chambers, each containing a shuttle with a different kind of
weft, and bringing these in line with the race-board, as required. In
this respect, therefore, the present device may be regarded as the
first recorded attempt to adapt the automatic weft-replenishing element
to perform the function of a checking motion.
The next following patent for a weft-replenishing device was that
granted to three Crawfords and Robert Templeton, of Beith, Ayr, and
described in the specification dated =17th= February, =1862=, No. 419.
This invention, which is of the shuttle-changing type, introduces
two distinctly novel departures from any previous invention of the
same class, namely, the employment of a six-chambered revolving
shuttle-box to bring fresh shuttles into working position, and also
what corresponds to a weft-feeling motion to effect the replenishing
of weft before the supply in use is quite depleted. The chambers of
the multiple shuttle-box are charged with reserve shuttles contained
in a hopper. At each change of shuttles the boxes revolved on
their common axis for one-sixth of a revolution to receive a fresh
shuttle in readiness for the next change. On arriving at the bottom
of its circuit, the discarded shuttle fell out of its chamber into
a receptacle. The weft-feeling motion operated the weft-changing
mechanism when the weft was nearly depleted. This was effected by
constructing the weft pirns or bobbins with a longitudinal slot to
receive a curved blade-spring fitting inside the shuttle so that it
entered the slot in the bobbin and passed underneath the weft. On the
weft becoming exhausted to a certain fixed point on the bobbin, the
blade-spring was automatically released, on which it projected through
a slot formed in the shuttle side. Thus, on the shuttle arriving in
its chamber of the rotary boxes, the blade-spring came into contact
with a part of the weft-changing mechanism which was thereby put into
operation to change the shuttles.
The foregoing brief descriptions of the first eight patented devices
for the automatic replenishing of weft in looms will serve to indicate
the general character which those devices assumed down to February,
=1862=. Although since that date to the present time the number of
patents for devices of that class of inventions number many hundreds,
yet it is significant that none of these later devices differ in any
essential element from those of earlier inventions. The table on
page 209 gives a list of weft-replenishing devices for which Letters
Patent have been granted, down to =1894=, with the date and number of
specification, the names of patentees, and type of device.
LIST OF PATENTS FOR AUTOMATIC WEFT-REPLENISHING DEVICES.
--------------------+--------------+--------------------------+----------------------------
| No of | |
Date of Patent. |Specification.| Name of Patentee. | Type of Device.
--------------------+--------------+--------------------------+----------------------------
(1) 1834, Mar. 20 | 6,579 | J. P. Reid and T. Johnson| Shuttle-changing
(2) 1840, Oct. 22 | 8,664 | Charles Parker | Shuttle-changing
(3) 1852, Apr. 28 | 14,092 | William Newton | Shuttle-changing
(4) 1857, Apr. 13 | 1,046 | Patrick McFarlane | Cop- or Bobbin-changing
(5) 1860, Apr. 4 | 861 | Thomas Ingram | Shuttle-changing }
| | | or Cop- or }Optional.
| | | Bobbin-changing }
(6) 1860, Nov. 14 | 2,787 | Julius Boeddinghaus | Shuttle-ejecting
(7) 1861, Feb. 5 | 301 | John Leeming | Bobbin-changing
| | | for Check Fabrics
(8) 1862, Feb. 17 | 419 | H., J., and R. Crawford | Shuttle-changing
| | and R. Templeton |
(9) 1863, Jan. 27 | 239 | J. Edmondson and T. | Cop- or Bobbin-changing
| | Ingram |
(10) 1864, Mar. 17 | 688 | J. Edmondson and T. | Cop- or Bobbin-changing
| | Ingram |
(11) 1864, July 19 | 1,803 | John Maynes | Cop- or Bobbin-changing
(12) 1865, Feb. 2 | 293 | John Maynes | Cop- or Bobbin-changing
(13) 1865, Sept. 20 | 2,395 | Joseph Edmondson | Shuttle-changing
(14) 1866, Jan. 1 | 1 | J. Bullough and W. | Shuttle-changing
| | Rossetter |
(15) 1866, Apr. 16 | 1,069 | Alf. Vincent Newton | Shuttle-changing
(16) 1866, Sept. 6 | 2,292 | John Bullough | Shuttle-changing
(17) 1866, Oct. 13 | 2,654 | Wm. Rossetter | Shuttle-changing
(18) 1868, July 28 | 2,366 | John Bullough | Shuttle-changing
(19) 1868, Sept. 10 | 2,788 | John Maynes | Shuttle-changing
(20) 1869, Sept. 28 | 2,820 | John Bullough | Shuttle-changing
(21) 1870, May 26 | 1,530 | Benjamin Cooper | Shuttle-changing
(22) 1872, Mar. 12 | 757 | A. M. Clark, from Paul | Shuttle-changing
| | Heilmann |
(23) 1874, May 1 | 1,542 | J. H. Johnson, from | Shuttle-changing
| | Arthur Villeminot |
(24) 1877, Jan. 27 | 356 | J. S. and B. A. Raworth | Semi-automatic
| | | Shuttle-changing
(25) 1888, Mar. 31 | 4,850 | Jacob Jucker | Shuttle-changing
(26)} {| 10,633 |}A. G. Brookes, from {| Cop- or Bobbin-changing
(27)}1891, June 23 {| 10,634 |} W. F. Draper {| Shuttle-changing
(28)} {| 10,635 |} {| Cop- or Bobbin-changing
(29) 1894, Apr. 26 | 8,251 | H. Bourgeois | Shuttle-changing
(30) 1894, Oct. 2 | 18,611 | G. O. Draper | Cop- or Bobbin-changing
(31) _1894, Nov. 27_| _22,939_ | _A. G. Brookes, from | _Northrop device for
| | W. F. Draper_ | Cop- or Bobbin-changing_
--------------------+--------------+--------------------------+----------------------------
During the periods of four years ending December, =1900= and
=1904=, there were 34 and 163 British patents respectively
granted for inventions relating to devices for the replenishing of
weft automatically in looms, which figures bear striking evidence of
the amount of energy and inventive talent which have been expended in
this direction during the past few years. And how forceful are these
figures when contrasted with the number of patents (31) extending over
the first period of 61 years. It was, however, not until after the
advent, in =1894=, of the Northrop automatic loom, which received
such favourable reception by American manufacturers, that the adoption
of automatic looms was taken into earnest consideration by British
manufacturers, many of whom now recognize that in one form or another
such looms have a definite sphere of usefulness in the manufacture of
a great variety of different classes of fabrics of simple construction
and embodying one series each of warp and weft threads.
=The Northrop Weft-replenishing Device.=
The most characteristic features and essential elements of this device,
and also those which distinguish it from all previous inventions of
this class, consist of the removal of cops or bobbins of weft that
are conveniently retained in a =circular rotary hopper= or
magazine, and of their insertion into a =self-threading shuttle=,
by mechanical means operated automatically either on the breakage or
depletion of weft, or else when the weft is depleted to a predetermined
amount, as may be elected. The magazine containing the reserve
supply of weft is always mounted above the shuttle-box situated on
the right-hand side of the loom, as represented perspectively in Fig.
167, which shows a bobbin-hopper A from which a pusher B is in the act
of removing a full bobbin of weft and inserting it into the shuttle,
thereby ejecting the previous bobbin C which falls down a chute into a
box D.
[Illustration: FIG. 167.]
[Illustration: FIG. 168.]
The parts of this device are better represented by the sectional view
shown in Fig. 168, which illustrates a cop-hopper A freely mounted on a
stud E to permit of its partial rotation, intermittently, immediately
after each successive change of weft, so as to bring into position
another cop to be in readiness for the next change of weft. The hopper
here shown is one constructed with sockets for 28 cops, F; but the
space occupied by the pusher reduces its actual capacity to 25 cops.
These are previously placed upon skewers, G, of special construction,
after which they are disposed in a horizontal position around and
between the rims of two discs or plates that are formed with notches
for the reception of the skewers, as represented in the diagram.
The conditions under which a change of weft is effected depends
entirely on the equipment of the loom, which may be adapted so that a
change will take place only when the weft either breaks or otherwise
fails in its supply; or else the loom may be furnished with an
attachment known as a “weft-feeling” device which effects a change of
weft immediately before the previous supply is completely consumed,
albeit, in this case, if the weft should break, the loom will stop
automatically, as under ordinary conditions. The object of this device
is to avoid such defects as are liable to be caused in cloth in
consequence of broken and missing picks of weft, and so produce cloth
of superior merit. If, however, such a device is not employed, the
weft-changing mechanism is put into action, on the failure of weft,
by the weft-fork hammer pulling backward the weft-fork, as usual. But
whether the operation of the weft-changing device is controlled by
the weft-fork or by the weft-feeler, the object in either case is to
cause the notched and free end of a trip-finger H to tilt upward from
its normal position, as shown in the diagram, so that on the forward
stroke of the slay K the finger will be struck by a bunter J fixed on
the front of the slay-baulk. The trip-finger is loosely mounted on a
stud fixed at the bottom of a short arm of an L-lever which constitutes
the pusher B, fulcrumed freely on a stud L. Thus, in the event of the
trip-finger being tilted on the forward stroke of the slay, the free
end of the pusher, which reaches over the ready-positioned cop in the
hopper, is suddenly depressed when the slay is at its extreme _forward_
position, thereby removing that cop from the hopper, and forcing
it into the shuttle M, through the bottom of which the previous
cop-skewer is expelled and passed down a chute N. The next flight of
the shuttle causes the weft thread to pass through a slit formed in a
brass casting fixed in the upper side of the shuttle, and then to enter
the shuttle eye automatically. At the same time, the remnants of both
weft threads are severed near to the selvedge of cloth and also at a
point near to the hopper, so that they shall not become obstructive
or involve the risk of being carried along accidentally into the
warp-shed. All these operations occur in proper rhythmical sequence
whilst the loom continues to run at full speed, which, for a loom of 36
inches reed-space, may be up to 150 picks per minute.
=The Hattersley Weft-replenishing Device.=
(_Patent No. 22,523, 11th December_, 1900.)
The chief characteristic element which distinguishes this device--which
is one of the most successful modifications of the shuttle-changing
type--from other weft-changing devices, is the stopping of the loom
to effect the change of shuttles, and then the restarting of it,
automatically. The object of that course is to allow more time to
accomplish the change, and so avert the straining and breaking of the
mechanical parts, which are more liable to occur when the changing of
weft is effected whilst the loom continues to run at full speed, as in
all other automatic looms. It is also claimed that this arrangement
enables a loom to be run at the same speed as an ordinary loom of the
same width and construction, whereas continuous-acting looms require to
be worked at a slower velocity.
[Illustration: FIG. 169.]
[Illustration: FIG. 170.]
In the Hattersley loom, the reserve supply of shuttles that have been
previously furnished with weft are retained in a hopper or magazine
which is mounted on the breast-beam and facing the shuttle-box on
either the right-or left-hand side of the loom. The changing of
shuttles may be effected either by the action of the weft-fork only
when the weft actually fails from any cause, or else by the operation
of a weft-feeler, before the weft completely fails, as desired. In
either case a change of shuttles involves a series of six distinct
operations which occur in the following sequence, namely: (1) stopping
the loom, (2) raising the shuttle-box fender, (3) ejecting the
failing shuttle from its box, (4) removing from the magazine another
shuttle and placing it in the emptied shuttle-box, (5) lowering the
shuttle-box fender back into its normal position, and (6) restarting
the loom. These operations, of which the second, third, and fourth are
represented by diagrams in Figs. 169, 170, and 171, are accomplished by
means of a series of four tappets governed by an indented clutch-wheel,
all of which are loosely mounted together on the second-motion or
picking-shaft, at the same side of the loom as that on which the
driving-pulleys are situated. The clutch-wheel is driven by means of a
pinion carried by the loose driving-pulley, and revolves continuously,
so that when a change of shuttles is called for, an indent or notch
in the clutch-wheel becomes engaged by a lug which, being secured to
the tappets, turns these for one revolution, and thereby performs the
series of operations just enumerated. Thus, in the event of weft either
failing or becoming nearly depleted, either the weft-fork hammer or
else the weft-feeler motion, according to the equipment of the loom,
first disengages the starting-handle to pass the driving-belt from
the fast or driving-pulley to the loose pulley, thereby stopping all
the primary movements of the loom, and at the same time putting into
operation the series of four tappets which effect the changing of
shuttles. Then one of the four tappets raises the shuttle-box front, C,
above the shuttle B, as shown in Fig. 169, to permit of the removal of
the shuttle. A second tappet then operates the pusher D, which advances
to eject the discarded shuttle from its box, whence it falls into a
receptacle, as shown in Fig. 170. A third tappet next operates the
feeder E, which removes the bottom shuttle from the hopper A and places
it in the same shuttle-box as that previously occupied by the ejected
shuttle, as represented in Fig. 171. The shuttle-box fender now falls
sufficiently to prevent the withdrawal of the newly inserted shuttle
from the box as the feeder withdraws and returns to the magazine to
receive another shuttle in readiness for the next change, after which
the shuttle-box front falls to its normal position, and finally the
fourth tappet replaces the starting-handle into its operative position
to transfer the driving-belt back again from the loose to the fast
driving-pulley and thereby re-start the loom.
[Illustration: FIG. 171.]
All the movements just described are performed during one complete
revolution of the tappets, and involve a stoppage for six picks,
corresponding to six revolutions of the crank-shaft. Therefore, in
a loom running at a speed of 180 picks per minute, the changing of
shuttles would involve a stoppage of the loom for only two seconds.
CHAPTER X
_THE PRINCIPLES OF DESIGNING_
The simplest form of interlacing the threads is the plain or tabby
weave. In this weave the threads intersect as often as possible, and
thus the greatest possible amount of firmness and strength is obtained
from a given quantity of material by this weave, with the exception
of leno or cross weaving, where additional firmness and strength is
obtained by the warp threads being partly twisted round each other in
weaving. Plain cloths may be ornamented by using threads of different
colours and of different thicknesses, as, for instance, if four picks
of blue and four picks of white are alternately put into a cloth,
the warp of which is composed of four ends blue and four ends white
alternately, a check is formed although the weave is quite plain. A
check may also be formed on a plain cloth by using one or more thick
threads at intervals in both warp and weft.
There is, of course, a limit to the number of threads of a certain
count which can be put into a plain cloth. Assuming that the counts of
warp and weft are equal, and that the number of picks per inch required
is the same as the ends, the number of threads per inch which can be
satisfactorily put into the cloth would not much exceed half the number
which could be placed side by side in one inch. Some allowance must
be made for the threads being bent out of a straight line and for
compression. This branch of design will be treated of more fully in
a subsequent chapter, but it will be obvious that this limit to the
number of threads of a given count which can be used in a plain cloth
renders the weave unsuitable for heavy fabrics. If a plain cloth is
very heavy and thick, it must of necessity be coarse.
[Illustration: FIG. 172.]
[Illustration: FIG. 173.]
Plain cloth can be made by using two shafts, but four are usually taken
with the draft, as shown at Fig. 172. This prevents overcrowding the
healds. By tying the first and second together and the third and fourth
together, the effect is the same as by using only two staves, only two
lifts being required.
[Illustration: FIG. 174.]
[Illustration: FIG. 175.]
=Twills.=--The simplest twill is the “2 and 1” twill, which is
woven with three shafts. A section through this twill is given at Fig.
173, where it will be seen the weft passes under one end and over two.
The structure of the fabric is better shown on “point paper,” as at
Fig. 174. The spaces between the perpendicular lines represent the
warp threads or “ends,” and the spaces between the horizontal lines
represent the weft threads or “picks.” By filling in the first square
on the first pick, it is shown that the first end is lifted for that
pick; and by filling in the second end on the second pick, it is shown
that the second end is lifted on the second pick, and so on. It is not
always advisable to take a filled-in square as representing a lifted
end, as it is often more convenient to fill in the weft squares or
those which are left down in weaving. If necessary, it can be stated
along with the design whether the marks represent warp or weft up.
Twilled weaves enable a larger number of threads of a given count to
be put into a fabric than in a plain cloth, and therefore these weaves
are employed in the production of the heavier kinds of cloths where
closeness of the threads is also desired.
[Illustration: FIG. 176.]
With three staves the twill given at Fig. 174 is the only one which can
be woven. The same twill may be woven with the warp predominating on
the face, and this would be represented on paper as at Fig. 176, where
two ends are shown to be lifted on each of the three picks.
In weaving this pattern three staves would be taken with the draft, as
given for Fig. 174 (see Fig. 175). The first stave will be lifted for
the first pick, the second stave for the second pick, and the third
stave for the third pick. These three lifts being repeated over an
indefinite number of times will produce small diagonal lines running at
an angle of 45 degrees across the piece, if the number of warp and weft
threads in a given space are equal. This twill is sometimes called a
“Jean,” and is used in the production of a fabric of that name, as well
as in “Jeannettes,” the latter with warp predominating on the face of
the cloth. In all these fabrics a large range of qualities is made.
With four staves the following twills can be made:--
1. One up, three down;
2. Two up, two down;
3. Three up, one down.
These are shown on point paper at Figs. 177, 178, and 179 respectively.
The third pattern is really the same as the first, being the reverse
of that pattern. It is advisable, however, to consider them as two
distinct patterns, since they give different effects when used for
purposes of combination, as will be seen later.
[Illustration: FIG. 177.]
[Illustration: FIG. 178.]
[Illustration: FIG. 179.]
=Five-shaft Twills.=--With five shafts of staves the possible
twills are--
1. One up, four down;
2. Two up, three down;
3. Three up, two down;
4. Four up, one down;
5. Two up, one down, one up, one down;
6. Two down, one up, one down, one up.
[Illustration: FIG. 180.]
[Illustration: FIG. 181.]
[Illustration: FIG. 182.]
[Illustration: FIG. 183.]
[Illustration: FIG. 184.]
[Illustration: FIG. 185.]
These are shown on point paper at Figs. 180 to 185 inclusive. There are
really only three different methods of interlacing the threads in these
six patterns; but, as stated previously, different effects are produced
in combination twills by all of them.
=Six-shaft Twills.=--With the increase in the number of shafts the
number of twills increases very quickly, as with a “repeat” of six
ends the following simple twill can be woven:--
1. One up, five down;
2. Two up, four down;
3. Three up, three down;
4. Four up, two down;
5. Five up, one down;
6. Three up, one down, one up, one down;
7. Three down, one up, one down, one up;
8. Two up, two down, one up, one down;
9. Two down, two up, one down, one up.
There are here five distinct methods of intersection, the remaining
four patterns being reverses. The patterns are shown on point paper at
Figs. 186 to 194.
[Illustration: FIG. 186.]
[Illustration: FIG. 187.]
[Illustration: FIG. 188.]
[Illustration: FIG. 189.]
[Illustration: FIG. 190.]
[Illustration: FIG. 191.]
[Illustration: FIG. 192.]
[Illustration: FIG. 193.]
[Illustration: FIG. 194.]
=Eight-shaft Twills.=--With a “repeat” of eight ends and picks the
number of changes which can be made in the basis of the twill is much
larger, and as the size of the repeat increases the possible twills
increase enormously. A selection of eight-end twills is given at Figs.
195 to 204 inclusive.
=Satin Weaves.=--In simple twills every pick is interlaced with
the warp in the same manner, but each successive pick commences, as it
were, one end further to the right or to the left, thus enabling every
end to be bound into the cloth in regular order. In satins the picks
are arranged differently. The object in a satin cloth is to obtain
an even surface, free from the bold lines of a twill; and thus it is
necessary to distribute the points of intersection of the warp and weft
as evenly over the surface of the fabric as possible.
[Illustration: FIG. 195.]
[Illustration: FIG. 196.]
[Illustration: FIG. 197.]
[Illustration: FIG. 198.]
[Illustration: FIG. 199.]
[Illustration: FIG. 200.]
[Illustration: FIG. 201.]
[Illustration: FIG. 202.]
[Illustration: FIG. 203.]
[Illustration: FIG. 204.]
[Illustration: FIG. 205.]
The commonest form of satin is the five shaft, and this can be woven
with five shafts with a straight draft lifted in the order 1, 3, 5, 2,
4. The relation between this satin and a five-end twill is shown at
Fig. 180, where it will be seen that on the second pick of the satin
the third end is lifted, on the third pick the fifth end is lifted,
then the second is lifted, and lastly the fourth. This distribution of
the points of intersection produces a satin. A slight twill effect is
given by most of these weaves, but it is nothing like so decided as
where the adjacent ends are lifted on successive picks, as in twilled
cloths.
The direction of the twill in the satin at Fig. 205 is from right to
left.
This five-shaft satin weave is used with weft preponderating over
warp, and also the reverse. Immense quantities of cloth are made
on both principles, and in all qualities. A regular make with weft
predominating is made with about 72 ends per inch of 32’s twist, and
picks ranging from 100 to 200 per inch of 40’s weft. A finer make is
used in large quantities for printing upon. This cloth counts about 26
ends × 45 picks per quarter-inch, and the yarns used are 60’s twist,
70’s weft. These are two of the standard makes of satins, but for
special purposes all qualities are made in cotton.
With the warp predominating a cheaper fabric is produced, as less
time is required to weave a given length. “Drills” are woven on this
principle, the proportion of warp to weft being about two to one.
[Illustration: FIG. 206.]
Satins may be produced on any number of shafts from five upwards. Fig.
206 is commonly called a four-shaft satin, but this is better classed
as a broken twill. The principle of its structure is essentially
different to that of a true satin.
A simple method of making a satin weave on any number of ends is to
find the first number which is not a measure of the number of staves
used, and take this as the basis of constructing the satin, as follows:
The first number which is not a measure of five is 2. Then, taking this
as the basis of the satin, assuming that the first stave is lifted for
the first pick, the third stave must be lifted for the second pick.
This gives the number of ends to be “skipped” over, and thus we can
obtain the satin by skipping over one each time, viz. 1, 3, 5, 2, 4.
It is advisable to put the numbers in a line or in a circle, and
re-arrange them underneath.
The order of lifting the staves for an eight-end satin can be obtained
as follows:--The first number which is not a measure of eight is 3.
Then, taking this as the basis, we lift the first stave for the first
pick and the fourth stave for the second pick, and “skipping” over two
each time we get the order, 1, 4, 7, 2, 5, 8, 3, 6. This is shown on
point paper at Fig. 207.
[Illustration: FIG. 207.]
[Illustration: FIG. 208.]
[Illustration: FIG. 209.]
A six-stave satin is irregular. It is impossible to form a satin with
six staves by “skipping” over a regular number of staves each pick, but
the points of intersection can be separated and a satisfactory satin
formed by lifting the staves in the order, 1, 3, 5, 2, 6, 4, or 1, 4,
2, 6, 3, 5. These are shown on point paper at Figs. 208 and 209.
A six-end satin weave is extremely useful, as it takes rather more
material than a five, and its irregular appearance is an advantage for
some purposes.
Fig. 210 is a seven-end satin.
[Illustration: FIG. 210.]
[Illustration: FIG. 211.]
Fig. 211 is a ten-end satin. Three is the first number which is not a
measure of ten, therefore three is taken as a basis in constructing
the satin, and the fourth stave is lifted for the second pick, and the
others in regular order.
Fig. 212 is a twelve-end satin. The basis in this case is five, as five
is the first number which is not a measure of twelve.
[Illustration: FIG. 212.]
[Illustration: FIG. 213.]
=Combined Twills.=--A useful class of pattern is obtained by
combining pick and pick two simple twills. If two eight-end twills
are combined in this manner, a pattern repeating on eight ends and
sixteen picks is produced. At Fig. 213 a “three and five plain” twill
is combined with a “three, two, one, two,” twill, and different effects
may be obtained by combining the same twills in all the possible
positions.
Figs. 214 to 220 show the effect produced by all the changes in the
relative position of the two twills. An immense number of patterns can
be made on this principle, as all the simple twills may be combined in
every position, and in each case a different pattern results.
On six ends we have seen that nine simple twills can be made, and
as each may be combined with the others in six different positions,
the number of patterns which can be obtained from this system of
combination is as follows:--Fig. 186 combined with each of the
others in one position each gives eight patterns, and as there are
six positions in which they can be combined, this gives forty-eight
patterns. Fig. 187 combined with Figs. 188 to 194 gives seven patterns,
and these in six positions give forty-two patterns. Fig. 188 combined
with Figs. 189 to 194 gives six patterns, and in the six positions give
thirty-six patterns. By going through all the changes in this manner
we get successively 48, 42, 36, 30, 24, 18, 12, and 6, or a total of
216 patterns. In addition to these, each twill may be combined pick
and pick with itself in four different positions without giving double
picks.
[Illustration: FIG. 214.]
[Illustration: FIG. 215.]
[Illustration: FIG. 216.]
[Illustration: FIG. 217.]
[Illustration: FIG. 218.]
[Illustration: FIG. 219.]
[Illustration: FIG. 220.]
=Drafting.=--The arrangement of the draft is a very important
matter in connection with dobby or tappet weaving. In the case of
simple twills, satins, and other regular weaves, as each end, or warp
thread, in the design is required to be lifted differently, a separate
stave is required for each end in the design, but in some patterns this
is not the case.
Fig. 221 is a stripe design composed of twenty ends of five-shaft satin
and sixteen ends plain. The least number of shafts on which this could
be woven is seven, five for the satin and two for the plain. The number
of picks to the round, or the number of picks on which the pattern
repeats is ten, ten being the least common multiple of two and five.
The draft may be shown either by ruling lines to represent the staves
as at Fig. 222, or on point paper as at Fig. 223. The latter is the
readier way, and is the way usually practised. The order of lifting the
staves is shown in the “pegging plan” (Fig. 224). The term “pegging”
refers, of course, to the dobby loom; if the design is woven on a
tappet loom, “tappet plan” would be a more correct term to use.
[Illustration: FIG. 221.]
[Illustration: FIG. 222.]
[Illustration: FIG. 223.]
[Illustration: FIG. 224.]
[Illustration: FIG. 225.]
[Illustration: FIG. 226.]
[Illustration: FIG. 227.]
When two weaves which consist of different arrangements of the same
ends are combined in stripe form, the same shafts will do for both
weaves. Fig. 225 illustrates this principle. In the design there
are sixteen ends of an eight-end twill, “2 up 2 down, 1 up 1 down,
1 up 1 down,” and sixteen ends of a mixed effect, which is simply a
re-arrangement of the ends of the twill. Each of the ends in the crape
or mixed weave can be drawn through the same stave as one of the ends
in the twill, as will be seen from the draft (Fig. 226) given with this
design, and thus the whole design can be woven with eight staves. If
the staves are lifted to form the twill with the first sixteen ends,
the different order of drawing the ends in the second part of the draft
causes the desired change in the pattern. The pegging or lifting plan
(Fig. 227) will therefore be the first eight ends of the twill.
[Illustration: FIG. 228.]
[Illustration: FIG. 229.]
[Illustration: FIG. 230.]
[Illustration: FIG. 231.]
[Illustration: FIG. 232.]
[Illustration: FIG. 233.]
One of the most useful principles of drafting is the V draft, or point
draft. Fig. 228 is a design based upon this principle; the design is
repeated twice over in order to show the effect better, and it will
be seen that the basis of the pattern is a “four and four” twill. The
first eight ends are drawn from right to left, and by reversing the
draft, as in Fig. 229, the pattern is made to repeat on fourteen ends.
The pegging plan (Fig. 230) will be the first eight ends and picks of
the design. The first and eighth staves have each only one end out of
the fourteen drawn through them, whilst all the other staves have two
ends in each pattern. The number on each stave could be made equal by
making the pattern repeat on sixteen ends and reversing the draft from
the ninth stave, with an eight-end twill basis.
[Illustration: FIG. 234.]
[Illustration: FIG. 235.]
[Illustration: FIG. 236.]
The V draft is used in a great variety of forms. It is not only in
stripes that it is used. It is very often employed in weaving all-over
spot effects and diamond patterns.
[Illustration: FIG. 237.]
Fig. 231 shows the principle applied to an all-over design. The draft
(Fig. 232) is given, showing how the ends are drawn through the
thirteen staves required to weave the pattern, and the “pegging plan”
(Fig. 233) shows the order of lifting the staves.
[Illustration: FIG. 238.]
A very effective method of employing this draft is illustrated at Fig.
234. This is a stripe design, and the general appearance would lead one
to suppose that a larger number of staves are required to weave it than
the eighteen actually required. Fig. 235 is the draft and Fig. 236 the
pegging plan for this design.
[Illustration: FIG. 239.]
[Illustration: FIG. 240.]
Another class of pattern produced by the V draft is the “diaper” style.
Fig. 237 is a small design of this kind, and it will be noticed that
the draft (Fig. 238) plays a very important part in increasing the size
of the pattern. The draft given shows how the pattern would be made on
nineteen staves.
It is not always advisable to draft a pattern to its lowest number
of staves, as it is not worth while saving one or two staves at the
expense of an irregular draft.
[Illustration: FIG. 241.]
=Dice Checks.=--Fig. 239 is a simple dice check pattern. Alternate
squares of warp and weft twill form the check effect, and it is
necessary to arrange the bindings so as to cross each other at the
edges of the squares, as otherwise the ends would “slip.” Fancy dice
patterns are produced by employing squares of different dimensions.
Fig. 240 is a pattern of this description. The bindings are here those
of an eight-end satin. To obtain the crossing of the binding dots at
the edges of the squares it is necessary to run the satin in opposite
directions in the warp and weft squares.
A still more fancy dice effect is given at Fig. 241. The bindings are
on the five-end satin basis, and the blocks of warp and weft satin
are arranged so that the design repeats on fifty ends and picks. It
is necessary in this class of binding to commence the satin in the
position indicated in the design. By a judicious arrangement of the
warp and weft blocks a large variety of patterns can be produced. The
principle is extensively employed in the production of fabrics for both
the home and shipping trades.
[Illustration: FIG. 242.]
[Illustration: FIG. 243.]
“Barley corn” patterns are a related style. The structure of
these cloths is shown at Figs. 242 and 243. The former pattern is
manufactured on an extensive scale, as it is a fabric in regular use
for making-up purposes. Fig. 243 has the weft square rather larger than
the warp, and is usually made in rather a better quality than Fig. 242.
In fine makes the size of the squares is often increased.
[Illustration: FIG. 244.]
[Illustration: FIG. 245.]
[Illustration: FIG. 246.]
[Illustration: FIG. 247.]
[Illustration: Twill. FIG. 248.]
[Illustration: Re-arrangement. FIG. 249.]
[Illustration: Twill. FIG. 250.]
[Illustration: Re-arrangement. FIG. 251.]
[Illustration: Twill. FIG. 252.]
[Illustration: Re-arrangement. FIG. 253.]
[Illustration: Twill. FIG. 254.]
[Illustration: Re-arrangement. FIG. 255.]
=Patterns produced by Re-arrangements of Twills.=--If the ends
of any twill be re-arranged in some _regular_ order, another pattern
of a different character is produced. For example, by re-arranging
the eight-end twill given at Fig. 244 in “satin order” the effect at
Fig. 245 is produced. The method of re-arrangement is to take the
first end of the twill design and place it in the first place in the
re-arrangement. The fourth end of the twill is then placed in the
second end of the re-arrangement, the seventh end of the twill in the
third place, and so on, the satin order used being 1 4, 7 2, 5 8, 3
6. Fig. 246 re-arranged in this manner gives the effect at Fig. 247,
and, as will be seen from the remaining figures (Figs. 248-255), the
effects produced by the re-arrangement are all good serviceable effects
which are useful for a great many purposes. With larger twills the
effects produced are more elaborate and varied, and the principle is
distinctly useful for the production of new woven effects.
[Illustration: FIG. 256.]
[Illustration: FIG. 257.]
[Illustration: FIG. 258.]
[Illustration: FIG. 259.]
[Illustration: FIG. 260.]
[Illustration: FIG. 261.]
[Illustration: FIG. 262.]
[Illustration: FIG. 263.]
Combined twills may also be re-arranged in this manner for the
production of new effects. Figs. 256 and 258 are two five-end combined
twills, and the effect produced by re-arranging the ends in five-end
satin order is shown at Figs. 257 and 259, respectively.
[Illustration: FIG. 264.]
[Illustration: FIG. 265.]
Fig. 260 is an eight-end combined twill, and Fig. 261 shows the effect
produced by its re-arrangement in eight-end satin order.
[Illustration: FIG. 266.]
[Illustration: FIG. 267.]
Fig. 262 is a twelve-end combined twill, and when re-arranged in
twelve-end satin order Fig. 263 is produced.
The effects produced by re-arrangement in satin order are, as a rule,
mixed effects of a less decided character than the original twill.
There are many other useful systems of drafting or re-arranging
patterns.
[Illustration: FIG. 268.]
[Illustration: FIG. 269.]
[Illustration: FIG. 270.]
Fig. 265 is the re-arrangement of Fig. 264 in the order 1 2, 6 7, 3 4,
8 1, 5 6, 2 3, 7 8, 4 5. This is a regular draft obtained by skipping
three shafts between each two ends. Another draft is obtained by
skipping one end between each two ends drawn through the healds.
Fig. 267 is obtained by re-arranging Fig. 266 in the order of the draft
1 2, 4 5, 7 8, 2 3, and so on, the draft repeating on sixteen ends.
Another useful draft (Fig. 270) as a basis for re-arrangement is the
one employed in producing Fig. 269 from Fig. 268. The order of the
draft is shown along with the design; the order runs, 2 1, 3 2, 4 3,
and so on, repeating on sixteen ends.
[Illustration: FIG. 271.]
[Illustration: FIG. 272.]
Some novel effects are obtained by re-arranging the ends of a
sixteen-end twill in the order 1 4, 7 2, 5 8, 3 6, 9 12, 15 10, 13 16,
11 14. The effect of this system is shown at Fig. 272, which is the
result of re-arranging Fig. 271 in the above order. The system is of
course applicable to other twills than those on sixteen ends.
=Twills combined to form Square Patterns.=--Simple twills may be
combined to form “square” patterns by taking alternate picks of each.
If two eight-end twills are combined in this manner only four picks
of each twill will be used in the combination. The principle will be
understood from Fig. 273.
This is a pattern composed of alternate picks of two ten-end twills
making an effect repeating on ten ends and ten picks. The effect given
by re-arranging this in satin order is shown at Fig. 274.
[Illustration: FIG. 273.]
[Illustration: FIG. 274.]
[Illustration: FIG. 275.]
Fig. 275 is a twelve-end pattern made on the same principle, and if
this is re-arranged in satin order, another effect is obtained.
Fig. 276 is a sixteen-thread pattern, and when re-arranged this
produces the rather peculiar pattern Fig. 277.
[Illustration: FIG. 276.]
[Illustration: FIG. 277.]
An immense variety of useful weaves may be obtained on this system
of combination, the effects being perhaps more useful than when the
patterns occupy twice as many picks as ends.
=Unequal Twills combined.=--Some useful fancy effects are obtained
by combining two unequal twills “end and end,” or “pick and pick.”
Fig. 278 shows the effect produced by combining “end and end,” a “three
and two” twill, and “two and two” twill. As one twill repeats on five
picks and the other on four, the combined pattern will occupy twenty
picks--twenty being the L.C.M. of five and four. There will
require to be twenty ends of each twill used to make up a complete
pattern, therefore the combined design will repeat on forty ends and
twenty picks. If a four-end twill is combined with a three-end twill
in this manner, the complete pattern would occupy twenty-four ends and
twelve picks, as twelve is the least number of picks on which both the
four-end and three-end twills repeat.
[Illustration: FIG. 278.]
=Check Patterns produced by Re-arrangement of Twills.=--If an
eight-end twill “three and five plain” is re-arranged in the order 1 4,
7 2, 5 8, 3 6, the effect shown in the square A (Fig. 279), and if this
be again re-arranged in the same order, the original twill results. It
follows, therefore, that by placing the pattern A above the twill and
drawing the ends through eight staves as indicated in the draft (Fig.
280), a check pattern will be formed. The draft which produces the
crape from the twill also produces the twill from the crape. The first
eight ends and sixteen picks of the design is the pegging plan. By the
addition of two extra staves the floats may be prevented from passing
from one square to another. To produce the check effect properly, the
satin draft must be such a one that if the fourth end is drawn on the
second stave, the second end must be drawn on the fourth stave. If a
sixteen-end satin draft is used for making a check pattern on this
principle from a sixteen-end twill, the satin draft must be selected
from those which can be made on sixteen shafts, and must be such a one
that exactly the same pattern will be produced in the opposite squares
of the check. The sixteen-end satin which gives this effect is the one
made by skipping eight ends between each lift.
[Illustration: FIG. 279.]
[Illustration: FIG. 280.]
=Honeycomb Cloth.=--In this style of cloth the threads are
interlaced so as to form squares, the centres of which are lower than
the ridges which form the sides. Fig. 281 is a honeycomb pattern on
ten ends and ten picks. It will be noticed that the ridges or raised
portions of the honeycomb are formed by the gradually increasing floats
of the weft and warp threads. The hollows are formed by the threads
weaving plain for a few ends and picks. Any size of pattern, within
reasonable limits, may be formed on this principle. Fig. 282 is a 16 ×
16 honeycomb on the same principle.
For smaller sizes the principle requires a little alteration. Fig.
283 is a good 8 × 8 honeycomb, and gives a fairly good effect even
in low makes of cloth. These honeycomb weaves are used for quiltings,
towellings, and for fancy goods of all kinds. Some excellent effects
can be produced by combining honeycomb with satin or other weaves for
striped dress goods, and similar fabrics. A good effect is given by the
pattern, Fig. 284. The weave requires very thick yarns for giving the
best effect. The pattern is reversible, both sides of the cloth being
exactly alike.
[Illustration: FIG. 281.]
[Illustration: FIG. 282.]
[Illustration: FIG. 283.]
[Illustration: FIG. 284.]
=Mock Lenos, or Lace Weaves.=--These weaves are very extensively
used in cotton manufacture. The imitation of leno fabrics can be
made extremely close, often so close as to deceive even experienced
buyers. The simplest kind is the pattern at Fig. 285, a “three and
three” pattern. The threads are interlaced in such a manner that the
first ends are pulled together by the second and fifth picks, and the
picks are pulled together in threes by the second and fifth ends, and
as the shed is crossed between the third and fourth picks, the crack
in the cloth appears there. The open effect is greatly increased if
the ends are reeded “three in a dent,” the first three ends in the
pattern being together in one dent, so that the reed assists in forming
the open effect. Sometimes the ends are reeded in threes with a dent
“skipped” between each full one, and this greatly augments the open
effect. A “four and four” mock leno is the weave shown at Fig. 286. To
produce the best effect this requires to be reeded four ends in a dent,
commencing with the first four ends in the pattern. In this weave the
crack is made between the fourth and fifth ends and fourth and fifth
picks. The principle of the weave is exactly the same as in the “three
and three” pattern, but a slightly more open effect can be obtained
with the “four and four” pattern. It is also suitable for a finer
make of cloth, as the open effect can be made with a larger number of
threads per inch.
[Illustration: FIG. 285.]
[Illustration: FIG. 286.]
[Illustration: FIG. 287.]
[Illustration: FIG. 288.]
A “five and five” pattern is given at Fig. 287. The second, fourth,
seventh, and ninth ends serve to pull the picks together in fives, and
to make a decided crack in the cloth between the fifth and sixth picks
in the pattern. The same thing takes place with the ends, they are
pulled together in fives, by the second, fourth, seventh, and ninth
picks.
Probably the best open effect is produced by Fig. 288. This is called
a “five and one” mock leno or lace. To produce the best effect, the
pattern should be reeded as follows:--
Five ends one dent,
Skip a dent,
One end one dent,
Skip a dent.
Two repeats of the pattern are shown at Fig. 288, only six ends and
six picks being required to weave it. The first five picks are pulled
together by the second and fourth ends, and as the shed is crossed
between the fifth and sixth picks and between the sixth and the
succeeding pick, the single pick No. 6 is shown in the middle of the
crack between the bars of five picks. The same thing takes place with
the ends.
It is not absolutely necessary to reed the pattern other than two in
a dent; an open effect is produced with the ordinary reeding, but the
special reeding greatly increases it.
=Cords.=--Cords can be formed in cloth by simply making a number
of threads lift together, as in Fig. 289. The cord may be made across
the piece by putting a number of picks in a shed, as shown at Fig. 290.
This principle of forming cords has its disadvantages. If the cord
is going lengthwise of the piece a large number of picks per inch is
required to give a good and fine effect, and there is always a tendency
to show a perforated appearance in cords made on this principle, owing
to the threads being pulled together in threes or fours, or whatever
number of threads go to form a cord.
[Illustration: FIG. 289.]
[Illustration: FIG. 290.]
A good cord up the piece may be made by taking six or eight ends of
six-end satin and two plain ends. Fig. 291 is a pattern of this kind.
The six-end satin is used because the plain ends would make wrong
bindings with a five-end satin and the ends would slip. This principle
of making cords is very useful, as the effect being produced from the
warp, the cost is less than if produced from the weft.
[Illustration: FIG. 291.]
[Illustration: FIG. 292.]
[Illustration: FIG. 293.]
[Illustration: FIG. 294.]
[Illustration: FIG. 295.]
[Illustration: FIG. 296.]
For dobby patterns it is necessary to keep the number of shafts as
low as possible, and cords requiring only two shafts above the plain
are made as in Figs. 292 and 293. Fig. 294 gives a cord across the
piece, and is of rather a firmer character than an ordinary four and
four cord. Fig. 295 shows a useful principle of making cords across
the piece. Two picks are taken together, and three double picks from a
cord. The three plain picks serve to define the cord. A better effect
is obtained from Fig. 296, in which the double picks have a float
of five ends. This cord is very suitable for stripes, as it combines
extremely well with warp satin.
[Illustration: FIG. 297.]
[Illustration: FIG. 298.]
Fig. 297 gives a cord up the piece. The back of the cloth is plain,
each pick taking an equal part in forming the back. The plain also
serves to spread the ends, and so produces a firmer cloth than would
be obtained if the cord were formed on the principle of Fig. 299.
Sometimes the back of the cord is required to be rather looser, and is
woven to a small twill. At Fig. 298 a twelve-end cord is shown on this
principle, with a 2 and 1 twill pattern at the back.
[Illustration: FIG. 299.]
[Illustration: FIG. 300.]
Another form of cord is illustrated at Fig. 299. This shows a cord up
the piece caused by every pick interweaving with the first and second
ends, and only half the picks interweaving with the remaining six ends.
The ends interweaving with half the picks are looser than the other two
ends, and therefore have a raised appearance. The face of the cloth
is plain, with the lines formed by the two ends running up the piece.
A smaller cord is shown at Fig. 300, which repeats on six ends and
four picks. Fig. 301 is a pattern composed of crossed cords. Excellent
effects are obtained by combining larger cords in the same manner.
[Illustration: FIG. 301.]
[Illustration: FIG. 302.]
[Illustration: FIG. 303.]
[Illustration: FIG. 304.]
[Illustration: FIG. 305.]
[Illustration: FIG. 306.]
=Crapes.=--This is a name given to weaves of a small “seedy”
effect. Good effects of this kind are produced by Figs. 302 and 303,
which repeat on ten ends and six picks, and six ends and six picks,
respectively. Another very largely used pattern is that at Fig. 304.
This is a pattern of rather peculiar construction, as both sides of
the cloth are alike, and the small floats of three are bent somewhat
out of a straight line. The reason for this can be seen by a careful
examination of the pattern. Patterns of the same character, but with
very large repeats, are often used. In many of these there is no
regularity in the construction of the pattern. The chief object is to
get a perfect all-over effect free from lines or rows. This can be
accomplished by keeping about the same amount of float on every pick
and distributing the floats as evenly as possible. A pattern of this
kind, on forty picks and sixteen ends, is given at Fig. 305. It will be
seen that each pick has two floats on it.
=Fancy Effects.=--Some novel effects can be produced on the
principle of Fig. 306. Two picks are floated on the top of a plain
cloth every ten picks, and these loose picks are bound only by two ends
out of every twelve. The loose picks are pulled in opposite directions
by the loose ends, and the result is that small hexagonal figures are
formed after the manner shown at Fig. 307. By using coloured ends and
picks for the loose ones a still better effect is obtained.
[Illustration: FIG. 307.]
[Illustration: FIG. 308.]
=Crimp Stripes.=--These are usually produced by having two warps
at different tensions. The warp to weave the crimp is lightly weighted
as compared with the warp of the other stripe, which may be plain or
satin as desired, and is let off intermittently. If the crimp warp is
very hard twisted the effect is increased. Fig. 308 is the design of
a crimp stripe of rather a novel character. The ends woven entirely
plain are on a beam lightly weighted, whilst the other ends are heavily
weighted. The first two picks are of ordinarily twisted weft, and the
third and fourth picks are very hard twisted. These picks are thrown to
the back, and take no part in forming the cloth in one portion of it.
The consequence is that these picks, loose at the back of the cloth,
and being very hard twisted, pull the two edges of the stripe closer
together, and thus form a crimp or “tuck” the length of the piece. The
plain ends form a crimp in the ordinary manner, owing to being lightly
weighted.
[Illustration: FIG. 309.]
=Huck Patterns.=--This is the name given to a class of patterns
used for towellings. The object is to get a firm cloth with a rough
surface. Fig. 309 is a weave of this description, but there are many
others in use. The pattern repeats on ten ends and eight picks, and can
be drafted down to be woven on five shafts.
[Illustration: FIG. 310.]
=Extra Warp.=--When some warp ends are used for figuring without
taking any part in forming the ground or body of the fabric, they are
termed “extra warp” threads. The principle is much used for putting
coloured spots or figures on grounds of a different colour or material.
In Fig. 310 the ends on which the black squares occur are “extra ends,”
as they take no part in forming the ground of the fabric. In this
figure the black squares represent the warp lifted. Where the extra
warp is not forming the figure it is thrown to the back of the cloth,
where it hangs loosely unless it can be bound into the ground cloth
or cut off. Two or three differently coloured spots may be formed
one above the other. Fig. 311 will show the principle of this. The
ground of the cloth is plain, and these ends are distinguished by the
small dots in the design. The first and second ends in the design are
supposed to be of different colours. This design will repeat on forty
picks, and any desired number of ends may be used between each stripe
for the ground. The extra warp must be put “extra” in the reed, so
that, supposing there are two ends in a dent in the ground, there would
be six in a dent where the two extra warps occur. The principle is
useful for obtaining a large width of pattern.
[Illustration: FIG. 311.]
[Illustration: FIG. 312.]
The extra ends may be of the same colour as the ground, but of thicker
material, and may be used with the object of increasing the width of
the pattern. Fig. 312 is a small striped design illustrating this
principle. The ground is plain, and the extra warp threads, if of
sufficient thickness, give a bold well-covered figure, which enables
the design to be woven on nine shafts.
[Illustration: FIG. 313.]
=Extra Weft.=--Extra weft spots may be woven on exactly the same
principle by taking the weft “extra” instead of the warp. Fig. 313 is
a small spot design on the “extra weft” principle. The cloth would
require to have twice as many picks per inch as there are ends per inch.
The ground may be either plain, twill, or satin, but if it is required
to bind the extra material a twill is preferable.
Fig. 314 is the commencement of a small design for an extra weft figure
on a “two and two” twill ground, showing how the extra weft may be
bound to the ground of the fabric without showing through to the face.
The extra weft may be brought up under the weft floats of the twill,
and if a fair quantity of material is used the binding will not be
visible on the face of the cloth.
[Illustration: FIG. 314.]
[Illustration: FIG. 315.]
It is impossible to bind extra weft to a plain ground or to a warp
satin ground in the ordinary manner, as there is no float to hide the
binding under. It may, however, be bound to a warp satin ground by
means of stitching threads, after the manner shown in Fig. 315. This is
an extra weft spot on a warp twill ground, and the loose picks at the
back of the cloth are bound by the stitching thread A. This thread is
really an extra warp thread, and it is lifted in such a position that
the binding is hidden under the warp floats of the twill ground. One of
these threads may be used at intervals of an eighth to a quarter of an
inch.
In binding extra warp the same principle applies. Extra warp may be
bound to a warp ground by lifting it between two warp floats, or it may
be bound to a weft ground by using an extra stitching _pick_ on
the principle illustrated in Fig. 315.
[Illustration: FIG. 316.]
Extra warp or weft is often used to produce a solid figure on a light
or open ground. Fig. 316 is a small design of this kind, in which
one half the picks are thrown out of the cloth in the ground of the
pattern. The design gives a very close imitation of a figured leno
cloth, if woven with suitable yarns. To obtain a good effect there
should be at least twice the number of picks per inch that there are
ends or warp threads. When the cloth is taken out of the loom the loose
threads are clipped and passed through a shearing machine, where the
loose threads are cut off close to the figure.
The extra picks should be bound round the figure by weaving plain
for a few ends, to prevent the extra material being pulled out of the
figure in clipping or shearing.
=Extra Warp and Extra Weft combined.=--Where extra warp and extra
weft are used together in the same part of the design, the structure is
a little more complicated.
A small check pattern of this description is given at Fig. 317. Every
alternate end and every alternate pick are extra, and all the even
numbered ends and picks belong to the ground cloth, which in this case
is woven plain.
In making designs employing both extra warp and weft, it is advisable
to put the dots of the ground weave on the point paper first. Then dots
may be put on to lift the extra warp where it is required to form the
figure, and if it is required to throw the extra weft to the back of
the ground cloth when the extra warp is on the face, the ground ends
must be lifted on the extra weft picks where required.
[Illustration: FIG. 317.]
In Fig. 317 the ground weave is shown in solid squares; the extra warp
is lifted by the small circles, and the extra weft is thrown to the
back of the plain cloth by the small dots, which lift all the ground
ends on the extra picks where the extra warp is lifted. This design
is made for single picks, but in the majority of looms there are only
change boxes at one side, and so the design must be arranged for two
picks alternately of ground and extra weft.
=Double Weft Face.=--Double weft-faced cloths are made on the
principle shown at Fig. 318. There is a face weft and a backing weft,
and both sides of the cloth may be made alike by using only one count
of weft.
[Illustration: FIG. 318.]
The pattern is a four and one twill for both face and back, and it is
important that the binding should take place under the floats of the
twill, after the manner described in binding extra weft.
The face pattern may be different from the back, but it is not possible
to back a cloth with every pattern on this principle, as the binding
must not show through to the face, and therefore the back pattern must
be selected so as to give this result.
Fig. 319 is an eight-end twill backed with weft, the back pattern in
this case being a “seven and one” twill.
[Illustration: FIG. 319.]
[Illustration: FIG. 320.]
[Illustration: FIG. 321.]
[Illustration: FIG. 322.]
Suppose it is desired to put a weft back to the pattern, Fig. 320, and
to have two face picks to one back pick. The face pattern must be put
on the face picks as in Fig. 321, and the back pattern must then be put
on in such a manner that where the backing weft is passing over one of
the warp threads there must be at least one weft dot above and below
it, as in Fig. 321.
Two wefts of different colours may be made to form reversible figures
by making them change places, first one being on the face, and then the
other. The principle is shown at Fig. 322, where the alternate picks
are of different colours. The two wefts should be thick enough to cover
well, and a fine warp should be used.
[Illustration: FIG. 323.]
[Illustration: FIG. 324.]
[Illustration: FIG. 325.]
=Double Warp Face.=--This is the same as “double weft face”
weaving, with the exception that two warps are used instead of two
wefts. A four and one twill backed with warp is shown at Fig. 323. It
is necessary to have the warp threads close enough together to hide the
bindings. Fancy patterns may be backed with warp by binding the backing
warp under warp floats in the face cloth.
Corkscrew twills are those which have a warp face on both sides of
the cloth. The weave is chiefly used in the manufacture of worsted
coatings, and similar goods, but is often employed in cotton designs.
An eleven-thread corkscrew is given at Fig. 324, and a fifteen-thread
pattern is given at Fig. 325. The weave requires a large number of warp
threads per inch to give a good effect.
=Padded Cloths.=--To obtain a raised effect on cords or figures,
thick weft may be inserted between the face and back cloth, or between
the face cloth and backing ends when there is no backing weft used.
This thick weft takes no part in forming either the face or back cloth,
and is simply held in position by the binding of the backing material
to the face cloth.
[Illustration: FIG. 326.]
A simple example of this principle of weaving is given at Fig. 326.
This pattern may be woven with one shuttle, and a fine raised cord
across the piece is formed. The backing warp threads, on which the
solid squares are placed, should be on a separate beam, and should be
heavily weighted as compared with the other ends. All the marks in the
design represent the warp lifted, so that the empty squares represent
warp left down. It will be noticed that the heavily-weighted ends are
only lifted for two picks in every ten, and this forms a cord effect.
There are three picks in each cord which do not interweave with either
the face or backing ends, but they serve to increase the boldness of
the cord by giving it a raised appearance. The three picks which form
the padding are the second, fourth, and sixth in the design.
The section at Fig. 327 will better explain the principle of the
pattern. There are five plain picks in the cord, two plain picks
between the cords, and three padding picks, making altogether ten to
the round. These cloths are known as Piqués.
[Illustration: FIG. 327.]
[Illustration: FIG. 328.]
Another padded effect is given at Fig. 328. The double pick is the
padding weft, and should be of thick material. The plain face cloth is
developed in small dots, and the backing ends in solid squares. The
padding picks in this pattern are pulled out of a straight line, and a
diamond effect is produced on the cloth.
=Double Cloths.=--Double-warp-face and double-weft-face cloths are
usually classed as double cloths, but they are essentially different
from double cloths made from two warps and two wefts.
[Illustration: FIG. 329.]
[Illustration: FIG. 330.]
Figs. 329 and 330 will show how two separate cloths, one above the
other, can be woven in one loom. The first figure shows one of the face
ends only lifted, and a pick being put in the face or top cloth. It
will be noticed that both back ends are in this case down along with
one of the face ends. The second figure shows both face ends lifted and
one of the back ends, whilst a pick is being put in the back cloth.
Two separate cloths of any pattern may be woven by simply lifting the
face ends out of the way when a pick is being put in the back cloth.
If a pick is put in the face and back cloth alternately, the cloths
will be bound together at both selvedges; but if two picks are put in
each cloth alternately, they are only bound at one side. This will be
seen from Figs. 331 and 332. In the former the pick passes from the
face cloth to the back cloth at one side, and from the back cloth to
the face cloth at the other side of the loom. In Fig. 332 two picks
are put in each cloth in succession, and the cloth will open out to
double the width of the loom. The former principle is used for weaving
sacks, meat-bags, and seamless pillow-cases. In putting double cloths
on point paper it is usual to use different colours or marks for the
face and back cloths respectively, and also for lifting the face cloth
when weaving in the back one. It is also advisable to always take the
dotted squares as warp lifted.
[Illustration: FIGS. 331, 332.]
The following directions for double cloth designing will be found
useful.
First mark off the face and back ends and picks respectively. Then on
the face ends and face picks put the face pattern, and on the back ends
and back picks put the back pattern. On every back pick lift every face
end. This will make the two cloths separate.
[Illustration: FIG. 333.]
[Illustration: FIG. 334.]
[Illustration: FIG. 335.]
Fig. 333 is the design for two separate plain cloths bound at both
sides of the loom, and Fig. 334 is the pattern for the cloths bound
only at one side. The face and back cloths may be of different
patterns, and bound together to form one thick fabric.
Fig. 335 is a design for a double cloth with a two and two twill face
and a plain back. The design is end and end, and pick and pick.
[Illustration: FIG. 336.]
The binding of the two cloths together is a very important matter. It
must be done in such a manner that the bindings are not visible on
the face of the fabric. To find the best position for binding the two
cloths together it is generally advisable to make a section showing the
first two picks in the pattern, as at Fig. 336. A position can then be
found for passing a _back pick over a face end_ where the floats
of weft in the face pattern will hide the binding. It will be seen that
this can be done effectually by passing the back pick over the fourth
face end, and so in the design the fourth face end is not lifted when
the first back pick is being put in.
Sometimes the face cloth is required to be much finer than the back,
and so there may be two face ends and two face picks to one back end
and one back pick.
[Illustration: FIG. 337.]
[Illustration: FIG. 338.]
Figs. 337 and 338 show a design for a fabric of this description, the
face pattern being a two and two twill, and the back plain. Before
commencing to put the design on paper, it is best to make a section
showing in what relative positions it is proposed to start the two
patterns, and so enable the weaves to be placed in such positions that
a satisfactory binding is possible.
[Illustration: FIG. 339.]
Fig. 339 shows how the binding may be effected by placing the two
patterns in a certain position in relation to each other. The binding
in this, as in the previous case, is made by passing a back pick over a
face end.
The binding may also be made by lifting a _back end over a face pick_
where the warp floats in the face cloth would cover it. A design
illustrating this kind of binding is given at Fig. 340. The face
pattern is a “four and four” twill and the back a two and two twill,
and there are two threads of face to one of back. The two cloths are
bound together by lifting the first back end on the first face pick
where the binding dot comes between two warp floats. The full squares
in the figure represent the face ends lifted; the small dots represent
the back ends lifted; and the circles show all the face ends lifted on
the back picks, which keep the two cloths quite separate. The cross on
the first pick effects the binding.
[Illustration: FIG. 340.]
The question as to which is the better system of binding depends upon
the character of the two cloths. If the face weft covers better than
the warp, it is the better way to bind by passing the back pick over a
face end, whereas if the face warp covers better than the weft, a back
end lifted over a face pick is preferable.
[Illustration: FIG. 341.]
[Illustration: FIG. 342.]
=Three-, and more ply Cloths.=--Any number of cloths may be woven
separately, one above the other, or several may be bound together to
form a very thick fabric. Fig. 341 is a design for weaving four plain
cloths, one above the other, and if the picks are woven in the order
given in the design it will weave a cloth four times the width of the
loom when opened out. The passage of the weft from one cloth to the
other is shown at Fig. 342.
[Illustration: FIG. 343.]
[Illustration: FIG. 344.]
=Figured Double Plain Cloths.=--If the warp be taken with
alternate ends of two colours and picked in the same manner, figures,
checks, or stripes can be formed by weaving two separate cloths of the
different coloured yarns, making both cloths solid colour, and making
them change places so as to form the desired figure. Fig. 343 is a
design for a small check pattern on this principle. The odd ends and
picks are, we will suppose, black; and the even numbered ends and picks
white. It will be seen that in the bottom left-hand square of eight
ends and picks, the lifting marks for lifting the face cloth out of the
way when weaving in the back cloth are put on the black ends and white
picks, and therefore the black cloth is lifted to the face in this
square. On the opposite square of eight ends and picks, the lifting
marks for separating the two cloths are put upon the white ends and
black picks, and therefore the white cloth is here made the face cloth.
By bringing either the black or white cloth to the face, any figure
may be formed, and the surface of the fabric is quite plain, which for
some purposes is much preferable to floated figures. The weave used may
be a twill or satin instead of plain, if desired, or the two cloths
may be of different weaves, and one brought through the other to form
a figure. Fig. 344 is a design for a small spot pattern on the double
plain principle. The threads should be “end and end” and “pick and
pick” of different colours, the first end and first pick being, we will
suppose, black, and the threads for the second cloth being white. The
lifting marks for bringing the back cloth to the face are the solid
squares, whilst the white cloth is brought to the top by the circles.
[Illustration: FIG. 345.]
If all the black ends and picks are brought together and all the white
ends and picks brought together, the pattern of both sides of the cloth
can plainly be seen as well as the ground weave. Fig. 345 will show
this. The face pattern is shown on the first sixteen ends and picks,
and the back pattern on the second sixteen ends and picks, whilst the
ground weave is shown for both cloths in the opposite corner squares.
The patterns may be designed in this manner, and the full effect
produced by arranging the draft so as to give the required effect in
the cloth.
Some fine effects may be obtained by inserting a thick end in the form
of padding between two plain cloths, and binding the cloths together
so as to make the thick end form a cord. The cords may run either
lengthwise or across the piece. Fig. 346 is a section showing how the
cord is formed by the thick end coming between the two cloths without
interweaving with either of them, and Fig. 347 shows how the point
paper design is made. The end on which the crosses are placed is the
thick thread which is used for padding, and the four ends at each side
of this are the two separate plain cloths. At each side of this there
are two ends showing where the two cloths change places, and so bind
the thick end between the cloths and form the cord.
[Illustration: FIG. 346.]
[Illustration: FIG. 347.]
Double plain cloths may be bound together by using sufficient material
to cover well, but the binding is difficult to make without being
visible. This principle of binding is shown at Figs. 398 and 399.
=Leno Fabrics.=--In a previous chapter the method of interlacing
the threads in simple gauze has been shown. With the two staves and one
doup required to weave gauze a considerable variety of patterns can be
woven. A “five and one cross-over” has already been given, but it will
be obvious that the number of plain picks in each bar of the cross-over
may be any _odd_ number. A “seven and one,” “eleven and one,” and so
on, are regular weaves.
Where the crossing thread weaves plain first at one side and then the
other of the standard end, a simple crack is made in the cloth between
the bars of plain, and there is no single pick in the middle of the
crack. The most common pattern of this description is a “five and five
cross-over;” a plan, draft, and pegging-plan of this pattern is shown
at Fig. 348.
[Illustration: FIG. 348.]
In all these fabrics the effect is decidedly of an open or transparent
nature.
In some leno fabrics the object is not to get an open effect but to
get zigzag effects by crossing a thick end over a few plain ends. A
simple pattern of this kind was given at Fig. 139 in dealing with
leno weaving, but the effect may be varied by making the crossings at
irregular intervals.
[Illustration: FIG. 349.]
Fig. 349 is a fancy crossing in which the thick doup end is crossing
over three double plain ends.
Fig. 350 is another fancy effect on the same principle. The marks on
the plain ends show when these ends are lifted.
When the thick crossing ends all work in the same direction a “wave”
effect is produced, which is often employed in conjunction with the
“diamond” or “eye” effect, obtained from the opposite working of the
two thick ends.
[Illustration: FIG. 350.]
[Illustration: FIG. 351.]
By using two doups a great variety of effect can be obtained. Fig.
351 shows a method much practised of making the picks bend out of a
straight line. It is obvious that this will require two doups, because
one doup thread has to be lifted for the first six picks, and the other
doup thread does not lift until the fourth pick in the pattern.
[Illustration: FIG. 352.]
=Check Lenos.=--Where alternate squares of leno and plain are
required to be woven, it is necessary to have two doups if the leno is
required to be woven four ends in a dent, with two ends crossing two,
as in Fig. 352. It has been shown how a check leno or gauze can be
woven with only one doup at Fig. 144, but the principle only applies
to pure gauze, or one end crossing one. The draft and pegging plan for
weaving a small check on the principle of Fig. 352 is given at Fig.
353, where it will be seen that eight shafts or staves are required
with two doups and two slackeners.
[Illustration: FIG. 353.]
[Illustration: FIG. 354.]
[Illustration: FIG. 355.]
For dobby weaving, the leno principle is chiefly used in the production
of striped fabrics. One of the most popular classes of fabrics is a
combination of the thick zigzag effect with an open leno effect of any
kind. Fig. 354 is an example of this combined style, the stripe can
either be woven with a satin or plain ground fabric.
With three doups some very elaborate effects can be obtained, but the
increased cost is rather prohibitive.
A thick end can be crossed round a pair of ends weaving leno, as in
Fig. 355. It is necessary to bring the end from the back stave round
the doup B before crossing under the pair of leno ends, as this would
make the crossing easier.
[Illustration: FIG. 356.]
[Illustration: FIG. 357.]
=Weft Pile Fabrics, Velvets, and Corduroys.=--Practically all
cotton velvets are woven on the weft pile principle. The intricate
nature of the loom required for weaving warp cut-pile prevents its
adoption for cotton pile fabrics. There is no doubt that a warp pile
woven over wires is superior to any weft pile fabric, all the pile
being perfectly even. The principle upon which weft pile is formed is
illustrated at Figs. 356 and 357, the former showing the pile uncut,
and the latter cut.
In weft pile fabrics the pile weft is usually “extra weft” issuing
out of the ground fabric only between every pair of ends. This forms
grooves or “races” in the fabric, which allow of the insertion of a
“knife and guide” which cuts the pile about the middle of the float.
At Fig. 356 the ground fabric is plain, and between each ground pick
there are three pile picks. The first pile pick passes under the first
end, the second pick under the third end, and the third pick under the
fifth end, and if these are repeated there are formed small grooves for
the cutter’s knife every two ends. The pattern is given on point paper
at Fig. 358, extended a little in each direction as the pattern repeats
on only six ends and eight picks. The ground picks (plain) are put on
in circles. A large number of picks per inch are required; in a common
make about 260 picks per inch of 60’s weft are used, and about 74 warp
threads per inch, the counts of warp being usually 2-70’s.
[Illustration: FIG. 358.]
If there are 260 picks per inch, and one pick out of every four belongs
to the plain ground fabric or “back,” as it is sometimes called, there
will be sixty-five picks per inch in the plain, and the pile weft is
“extra” material forming grooves for the cutter’s knife on the face of
the cloth.
[Illustration: FIG. 359.]
After the cloth is woven it is stiffened, and stretched in a frame for
cutting. Fig. 359 shows the kind of knife used for this purpose. The
guide A is selected so as to fit under the float easily and lift the
centre of the float to the cutting edge B. The cutter inserts the knife
and guide every two ends or “race,” and thus in a common velvet, as at
Fig. 358, one-third of the pile picks are cut each time the knife is
run up the piece. The arrows show the ends where the knife is inserted.
Machine cutting is now adopted to some extent for velvets. The piece
is moved backwards and forwards automatically, and so the cutter does
not require to walk the length of the frame every time the knife is run
up the piece.
The term velvet is used by retailers and the general public as
referring to silk velvet, and by them all cotton pile fabrics are
termed velveteens; but in the trade the lighter and finer classes of
cotton weft pile fabrics are velvets, and the heavier kinds, such as
those used for clothing purposes, are called “velveteens.” There is no
very definite line drawn between the two classes.
Velvets are usually sold by weight when in the grey state. The pattern
given at Fig. 329 is made to weigh from 18 lbs. to 30 lbs. for 100 or
110 yards, 24 inches wide, the yarns being as previously stated, and
the various weights obtained by altering the number of picks per inch.
About 25 lbs. per 110 yards is a medium weight.
The usual width for home trade velvets is 24 inches (grey), but for
shipping 22½ inches is a very common width. The pieces are usually
woven two or three in a width of the loom, and afterwards torn asunder.
The length of the pile may be increased by increasing the length of the
float. Fig. 360 is a pattern with a seven float, and four pile picks to
each backing, or ground pick. This is usually called an E1 velvet, a
term probably handed down from the origination of the pattern.
[Illustration: FIG. 360.]
Until well into the last century the pattern Fig. 358 was the only
weave used in the production of cotton velvets, and a patent was
obtained for this E1 velvet, and the term “Patent” is still regularly
used when referring to velvets with a longer pile than a five float.
An E1 velvet requires considerably more picks per inch than a “common
velvet.” A good make will contain 400 or more picks per inch of 60’s or
70’s weft, woven in a 74 Stockport reed with 2-70’s twist.
Sometimes the points where the pile weft intersects are distributed in
satin order as in Fig. 361, but this makes no appreciable difference,
as the picks are so piled up on the top of each other that the bindings
of the four pile picks are practically in a horizontal line in either
of the methods given.
[Illustration: FIG. 361.]
[Illustration: FIG. 362.]
Fig. 362 is a design for a velvet with a nine float, and five pile
picks to one back pick or “binder,” as they are sometimes termed. This
would require a still larger number of picks, and would easily take 500
picks per inch of 70’s weft.
[Illustration: FIG. 363.]
A cloth is made with the same length of pile as the above, but with
only four picks of pile to each back pick. This pattern requires fifty
picks to complete it, as will be seen from Fig. 363. The pile in this
case will be much more firmly bound into the ground cloth than is the
case in Fig. 362.
=Fast Pile Velvets.=--When the pile weft is only bound under one
end it is rather liable to wear out, especially by rubbing at the back.
To obviate this, the pile weft is bound in the manner shown at Fig.
364, by which it is rendered much faster. When bound to the ground
fabric in this manner it is known as “fast pile.”
The method of binding detracts from the richness of the pile obtained
from a given quantity of material, but the fabric possesses much better
wearing qualities.
Fig. 365 shows the structure of an ordinary fast pile velvet with a
plain ground, and four pile picks to each back pick.
[Illustration: FIG. 364.]
[Illustration: FIG. 365.]
[Illustration: FIG. 366.]
A regular make of this fabric is as follows:
Width 26 inches, length 104 yards, weight 30 to 34 lbs. 76 reed, 420
picks per inch, 2-70’s twist, 50’s weft.
=Twill Backed Velvets.=--Some of the finest kinds of velvet are
made with a twill back. The chief advantage of a twill back over a
plain is that the bindings of the pile weft into the ground are hidden
by the twill floats at the back. This renders the pile much faster than
a common velvet; in fact, twill backs are usually sold as fast pile
velvets.
[Illustration: FIG. 367.]
Fig. 366 is a section showing the structure of the fabric, and it will
be easily understood that the pile cannot be so easily pulled out at
the back, owing to the weft covering the bindings. Fig. 367 is the
design for a good make of this kind of velvet, the back is a two and
one twill, and the pile weft floats over eleven ends.
An important thing to remember about twill backs is, that the pile
pick following a back pick must have the dot opposite a blank square in
the back pick. If this were not so, the picks would slip about and form
an irregular surface.
In the weave under notice, five pile picks are taken between the first
two back picks, two between the second and third, and five between the
third and first. This enables the proper bindings to be made.
This weave gives one of the best cloths that are made. It is usually
woven with about 600 picks per inch of 60’s weft, in a 76 reed with a
2-70’s twist.
[Illustration: FIG. 368.]
Another pattern of the same kind which will take still more weft is
given at Fig. 368. In this there are five pile picks to each backing
pick, and the pattern repeats on thirty-six picks.
=Plushes.=--When much longer piles are required the fabric is
called “plush.” These can be made on exactly the same principles as
the foregoing, or the principle embodied in Fig. 369 may be used. In
this weave the pile is bound in much oftener than in the shorter piled
cloths, as a long pile is much easier to pull out than a short one,
and therefore requires more firmly binding. The ground picks also in
this weave are all alike, i.e. they all pass under the same ends, and
this does not hold the pile weft as firmly as a proper plain back,
although it utilizes the binding of the pile weft as forming part of
the back pattern. The bindings of the four pile picks together form a
plain pick, and the back of the cloth thus appears perfectly plain.
To preserve an even surface of pile it is necessary to distribute the
points, where the first pick in each four commences, in satin order. As
there are in Fig. 369 twelve ends on which the pile picks are bound,
the basis upon which the bindings must be distributed is a twelve-end
satin, which runs 1, 6, 11, 4, 9, 2, 7, 12, 5, 10, 3, 8. The first
pile pick commences to bind on the second warp thread, and therefore
the first pile pick in the second set of four (the seventh pick) must
commence to bind on the sixth of the ends available for the purpose
(the twelfth end). The whole design will be complete on sixty picks.
[Illustration: FIG. 369.]
For a longer pile the weft would require to be bound under more ends,
especially if the backing picks are not crossed.
=Cord Velvets.=--A simple cord velvet can be made on the principle
of Fig. 370. The two plain ends on every six bind all the pile picks in
the form of a cord up the piece, and there is one ground pick to four
pile picks. The cutter’s knife is only run up every cord, and so the
cutting operation is much cheaper and more easily done than in the case
of velvets. After cutting, the pile is brushed, and the fibres spread
out so as to cover the space between the two binding ends as much as
possible.
An eight-end cord on the same principle is given at Fig. 371.
[Illustration: FIG. 370.]
[Illustration: FIG. 371.]
Round cords are made by employing floats of two lengths. In the
previous cords all the floats are equal, but in Fig. 372 one float is a
“thirteen” and the other a “fifteen.” When these are cut in the middle,
the short float forms the outside of a cord, and the long float the
inside, which gives the cord a round appearance. Fig. 373 shows the
appearance of the two pile picks when cut.
[Illustration: FIG. 372.]
[Illustration: FIG. 373.]
As a rule, these cords are used for very heavy fabrics, and twill and
satin backs are chiefly used, and as the pile weft is usually much
thicker than velvet weft, there are not so many pile picks between the
ground picks. A smaller cord on the same principle is given at Fig. 374.
[Illustration: FIG. 374.]
CHAPTER XI
_FIGURED DESIGN_
In figured fabrics it is most important that the distribution of the
parts of the figure should be such that the eye is not attracted
by lines formed by the unequal distribution of the figure. The
objectionable feature is most likely to occur in designs of an all-over
character, as it is almost impossible to tell if the distribution is
perfect without extending the design to cover a considerable space.
[Illustration: FIG. 375.]
In designs which consist of set or detached figures, it is a
comparatively easy matter to cover the surface of the fabric equally
by distributing the figures in some pre-arranged order. The simplest
method of arranging detached figures is to arrange them “one and one,”
as in Fig. 375. This is a small spot arranged from two points on twelve
ends and twelve picks, and the same principle will apply whatever the
size of the figure. The space to be covered, twelve ends and twelve
picks, is divided into two, both in warp and weft, and it will be
noticed that the central dot in each spot is in the same position in
each square of 6 × 6.
In designs of a floral character the two figures are generally turned
in different directions, and if the centres of the figures be properly
placed they may be turned in any direction, and still preserve the
equal distribution. Detached figures may be arranged in the order of
any satin, but the regular satins show the figures too much in lines,
and the system is not much practised on that account. Irregular satins
give much better effects. Fig. 376 is a design consisting of six spots
arranged in six-end satin order, on thirty ends and thirty picks;
the ground being five-end satin. In making the design the space to
be covered is divided into six parts, both in warp and weft, by the
crosses at the corners of the squares.
[Illustration: FIG. 376.]
The squares are numbered at the side in the order of the satin, viz.
1, 3, 5, 2, 6, 4, and the first spot is placed in the left-hand bottom
corner, the central dot of the spot being placed in the centre of its
square. The next figure is placed in the third square, on the second
five picks, the central dot again being placed in the middle of the
square. The third spot is placed in the fifth square, on the third
division of the picks; and so on, until the six figures have been
placed on the thirty ends and picks.
If the central dot is always placed in the correct position in each
division, the figures may be turned round or placed in any direction.
The ground weave is a five-end satin, and care must always be taken,
in designing, that the ends and picks in the pattern are a multiple of
the ends and picks in the ground weave, or there will occur a broken
pattern at the joining of each “repeat.”
[Illustration: FIG. 377.]
Fig. 377 is a small spot arranged in the order of a regular eight-end
satin on sixteen ends and sixteen picks. In making this design the
sixteen ends and picks divided into eight will give only two ends and
picks for each division, so that if the central dot of the first spot
is placed on the third pick, the centre of the next spot will come on
the fifth pick, and so on.
[Illustration: FIG. 378.]
As previously stated, when set figures are distributed in regular
satin order a stiff appearance is given to the design by the figures
showing in lines. It is therefore necessary to get some irregular
order as a basis to work upon, which will distribute the parts of the
figure equally, and give a mixed up appearance. A design based upon an
irregular eight-end plan is given at Fig. 378. The irregular satin upon
which it is based is given at Fig. 379. The method of constructing the
design is precisely the same as in the previous examples; the space
to be covered is divided into eight parts in each direction, and the
figures are arranged in the same order as the dots in Fig. 379. If ten
spots or figures are to be arranged in a design, an irregular ten-end
satin may be used. In arranging the order care must be taken to have
the dots evenly distributed.
[Illustration: FIG. 379.]
=Transferring from Sketch to Point Paper.=--In transferring a
design from the sketch to point paper, it is usual to rule the sketch
into small squares, each square to represent sixteen or twenty-four
ends and picks, and to mark the point paper into squares of this number
of ends and picks. The outline of the sketch is then drawn on the point
paper; the squares into which the sketch and point paper have been
divided render it a simple matter to enlarge the sketch and preserve
the proportions of the various parts of the design. If the sketch
measures four inches for one repeat of the pattern, and the design is
to be made on 400 ends, and say 500 picks, on 8 × 8 point paper, the
sketch may be ruled with lead pencil into twenty-five parts in the
warp, and the same number of parts in the direction of the weft. The
point paper would then require to be divided into spaces of sixteen
ends and twenty picks.
400 500
--- = 16 ends --- = 20 picks
25 25
=Development of the Pattern.=--When the outline of the figure has
been drawn on the point paper, it may be coloured in. This is done by
going over the line carefully and filling in all the squares that the
outline passes through. If the ground of the fabric is to be plain, the
outline of the figure must be kept plain--that is, it must move an odd
number of threads each time, so that the plain ground may be carried up
to the figure without spoiling it.
[Illustration: FIG. 380.]
If a solid weft figure is required on a warp satin ground the figure
may be coloured all over with, say, red paint, and the developing
dots be put on in blue or other colour; but if much shading or fancy
treatment is required, it is more convenient to develop the figure
in one colour, as in Fig. 380. Some designers colour the ground with
red, and put the satin or other dots over this in another colour,
leaving the figure white, and then develop the figure by putting on the
required red dots to lift the warp for shading or binding.
This method is advantageous where there is more figure than ground,
which is often the case; but, as a general rule, the figure is coloured
with red, and the binding dots of the ground in the same colour,
another colour being used for the binding of the figure when required.
[Illustration: FIG. 381.]
Fig. 380 illustrates the principle of developing a weft figure on a
warp satin ground by shading from warp to weft.
The outline of the figure is first sketched on the point paper, and
then the whole is covered with the satin dots. By adding single dots
where required any degree of light and shade can be obtained. It is
best to add the dots all to the same side of the float, and, as a rule,
it is most convenient to add them singly. The effect is obtained by
gradually increasing the float from one to seven, and thus there are
seven degrees of light and shade between the two opposite eight-thread
satins.
Fig. 381 will illustrate the principle of shading more perfectly. This
is a small stripe of shaded eight-end satin. The space to be shaded is
divided into seven equal parts of five threads each, as there are seven
changes to be made. The first five ends are left as they are, and a dot
is added to each one in the second division, two dots are added to each
in the third division, and so on, until the float of seven is reached
at the right-hand side of the stripe.
In a five-shaft satin there are only four possible changes, and
therefore this is not of much use for figured design in cotton goods.
The larger satins, such as eight, ten, and twelve-shaft satins, are
most useful for this purpose.
Twills may be shaded in the same manner as satins by gradually adding
to the float of a warp twill until a weft twill is reached.
Satin figures are somewhat flat and indistinct when woven with grey
warp and weft, and therefore in cotton fabrics the figures are more
often developed in twill or fancy weaves of a bold character, unless
coloured yarns are used. The best effect is obtained when a number of
different weaves are employed in developing a design; the variety in
itself prevents any appearance of flatness, which a design developed
entirely in satin or twill possesses, and the weaves may be selected so
as to suggest the beauties of the flower, leaf, or other object which
forms the basis of the design.
The object of the designer need not be to render a direct imitation of
nature; but there is no reason why a textile designer should not use
the power at his disposal of suggesting the surface appearance, or the
beauties, or characteristics of the object which forms the subject of
the design.
A portion of a design developed in a variety of weaves is given at Fig.
382. The combination of the solid weft mixed fancy weaves gives a good
effect.
In designs of the more conventional kind the outline of the figure
may be solid weft float, and the inside any other weave that fancy may
suggest.
[Illustration: FIG. 382.]
If the figures are formed from extra warp or weft, the same principles
of development will apply. Any variety of light and shade can be
obtained, and bold effects may be produced by twilling, or subdued
effects by interweaving the threads more closely and in satin order.
=Sizes of Patterns, and Casting Out.=--The Jacquard machine most
generally used in the cotton trade is a 400’s, which weaves a design
made on 400 ends or warp threads in a “repeat.” If the harness is tied
up to the 400 neck cords, and the warp drawn through every mail in the
harness, the designs made for this loom must either be on 400 ends or
on a number of ends which is a measure of 400. Thus a 400’s harness
will weave the following sizes of patterns:--
One pattern to 400, or 400 end pattern
Two patterns to 400, „ 200 „
Four „ 400, „ 100 „
Five „ 400, „ 80 „
Eight „ 400, „ 50 „
Ten „ 400, „ 40 „ and so on.
If it is required to make a design with three patterns to the four
hundred ends, the design must be made three times over, two patterns
occupying 133 ends each, and the other pattern occupying 134 ends to
make up the 400 ends.
A design six patterns to the four hundred may be made by designing four
patterns on sixty-seven ends each and two patterns on sixty-six ends
each, and other sizes not exactly divisible into the four hundred may
be made to come in on the same principle.
In designing for Jacquard weaving care must be taken that the ground
weave will divide exactly into the number of ends in the harness,
otherwise the pattern will be broken. Sometimes the figure will allow
of the ground being broken at some point or other without the break
being visible. Such opportunity occurs where the ground narrows down to
a fine point; but in ordinary cases, where it is necessary to make a
design with a ground weave repeating on a number not a measure of 400,
some of the mails must be “cast-out.”
For example, if the ground weave is required to be a 12 × 12 honeycomb,
as it will not divide equally into 400, but will divide into 396, the
design may be made on this number, and four mails in the harness left
empty.
Casting out is also resorted to when it is required to reduce the
fineness of the reed. For instance, if one-eighth of a 400’s harness be
cast out, there will be 50 ends less per pattern, and if the pattern
measures four inches, the reed would be reduced from a 100’s to an 87’s.
[Illustration: FIG. 383.]
If several rows are cast out, it is best to leave them out in two
places; usually one-half is left out in the first half of the machine,
and the remainder in the second half.
In designing for a machine which is “cast out,” it is necessary to know
in which part of the machine the ends are cast out, so that the design
may be made to tie up properly, and that proper instructions may be
given to the card-cutter.
=Striped Designs.=--Striped fabrics are always largely made for
dress goods and other purposes. An endless variety of styles may be
made by combining stripes of any two contrasting weaves. If the weaves
are combined for dobby weaving, care must be taken that too many shafts
are not required for the value of the effect obtained, but if intended
for Jacquard weaving, the stripes may be figured as desired.
Some of the most effective combined styles are made of satin and leno
in various forms and proportions. If for dobby weaving, the designs
may be spotted to come in on a reasonable number of shafts, but if
for the Jacquard, the satin is figured. The satin stripes are usually
crammed--that is, there are more ends in each dent of the reed in
the satin than in the other part of the fabric. Fig. 383 is a stripe
design, composed of alternate stripes of figured satin and “5 and
1” lace or mock leno. The reeding plan for this fabric will be as
follows:--
_Reeding Plan for Fig. 383._
48 ends satin, 4 in a dent = 12 dents
5 ends 1 dent }
Skip 1 dent } three times = 12 dents
1 end 1 dent }
Skip 1 dent }
5 ends 1 dent = 1 dent
---
25 dents in pattern.
This system of reeding the open work is the best for obtaining an open
effect, as pointed out in a previous chapter. Twenty-five dents are
occupied in reeding each pattern of seventy-one ends, and assuming the
harness to have one hundred threads per inch, the reed required to keep
the cloth the same width in the reed as in the harness will be--
71 : 100 ∷ 25 : 35·2 dents per inch.
The reed required is one with 35·2 dents per inch, or a 70’s
“Stockport” reed would be used. This calculation is for a complete
number of patterns, and does not allow anything for balancing the piece
by having a satin stripe at both sides, as is often the case.
In figured stripe designs the general effect is much improved by
placing the figure in different positions on each stripe in the 400
ends. If there are four figured stripes in the 400 ends, and the figure
repeats on 100 picks, the figure may be placed in four different
positions, moving twenty-five picks each time, in which case it would
have to be designed on 400 ends; or in two different positions, in
which case it would be designed on 200 ends. The object of this
distribution is to prevent the figure appearing in rows across the
piece.
[Illustration: FIG. 384.]
=Figured Diagonals.=--As previously explained, striped designs are
complete on the lowest number of picks into which all different weaves
in the design will divide without remainder. In figured diagonals the
design is complete on the first number that the diagonal and figure or
figures counted diagonally will divide into without remainder. Thus,
in Fig. 384 the design is complete on 48 picks, because the diagonal
repeats on 24 picks and the figure repeats on 16 picks, and the L.C.M.
of 24 and 16 is 48; therefore this is the number of picks to which the
design must be carried before it is complete.
=Selection of Point Paper.=--Point paper is divided into small
squares to represent the ends and picks, and if the designs are for a
300’s or 400’s Jacquard a thick line is required every eight in the
warp direction to mark off the number of rows of eight needles in the
machine. In 100’s Jacquards the needles are placed in 25 rows of four
needles in a row; in 200’s the needles are in 25 rows of eight needles,
in 400’s there are 50 rows of eight needles, and in 600’s there are
twelve needles in a row. The design on point paper must be divided by
a thick line to mark off the number of needles in a row; in a 400’s
machine this is always eight, in 600’s machines it is always twelve.
If the paper has a thick line every eight in the picks as well as in
the warp it is called “8 × 8,” and a design made on this paper will be
proportionately the same if woven into cloth with the same number of
ends as picks per inch.
If it is desired to make a design for a fabric with 96 ends per inch
and 60 picks per inch for a machine with eight needles in a row, the
paper required to keep the figure of the same proportions as it will
appear in the cloth will be 8 × 5.
96 : 60 ∷ 8 : 5
If the design is intended for a 600’s machine, the paper must be 12 ×
(_x_). If the cloth is to have 96 ends per inch and 120 picks per inch
in a 600’s machine, the paper required would be 12 × 15.
96 : 120 ∷ 12 : 15
In selecting paper for a figured crammed stripe design, a rather more
complicated calculation is necessary. It is necessary to obtain the
number of ends per inch in the figured stripe, thus:--If the satin is
figured in a stripe
{96 ends, 4 in a dent, satin}
{50 ends, 2 in a dent, plain}
woven in a harness 100 ends per inch, and the same width in the reed as
in the harness, the ends per inch can be obtained as follows:--
96 ends, 4 in a dent = 24 dents
50 ends, 2 in a dent = 25 dents
--- ---
146 ends. 49 dents.
If 49 dents are required for 146 ends, the number of dents per inch in
the reed will be--
146 : 100 ∷ 49 : 33-82/146 dents per inch, or a 67 reed.
If the reed used is one with 33½ dents per inch and the satin is
four ends in a dent, there will be 33½ × 4 = 134 ends per inch in the
satin; and if there are to be 100 picks per inch in the cloth, the
paper required to keep the figure proportionate would be for a 400’s
machine, 134: 100 ∷ 8: 6 (nearly).
Therefore the paper required is 8 × 6.
It is not at all necessary to use point paper ruled exactly in
proportion to the warp and weft, as the design can easily be elongated
or otherwise. It is only necessary to rule the sketch into squares,
representing a certain number of ends and picks, and to mark off the
point paper accordingly.
=Designs for Split Harness.=--In designing for the split harness,
Fig. 124, no ground dots are required on the design, as the shafts
under the comber-board which are lifted by the spare hooks weave the
ground pattern. The design is simply coloured in, and the binding dots
put on the figure only.
In a double-scale split harness every hook lifted takes up two ends,
and thus the bindings in the figure will appear in twos, and will
therefore appear rather coarse. In the ground every end is woven
separately by the shafts, and these will require to be lifted to give
the required ground weave. All that is required, therefore, is to put
the lifting dots on the point paper in the position required to operate
the hooks which lift the shafts. Except for the limit with regard to
the ground weave, designs for the split harness are prepared in the
same manner as for an ordinary harness.
=Pressure Harness Designs.=--In designs for the pressure harness
no binding dots are required on the point paper in either the figure or
ground, as the shafts or “pressure healds” in front of the harness do
all the binding.
This harness is chiefly used in fine goods. Several warp threads are
drawn through each mail in the harness, and afterwards woven singly by
the pressure healds in front.
The edges of the figure are stepped according to the number of ends in
each mail.
The structure of a pressure harness damask fabric, woven six ends in a
mail with eight shaft satin bindings, is shown at Fig. 385. Of course
it is not necessary to make the design on point paper in this manner;
all that is necessary is to sketch the figure and colour it in where
the warp satin is required. All the binding is done by the pressure
healds, as explained with Fig. 125.
[Illustration: FIG. 385.]
Designs woven with this harness have always a flat appearance, but this
is suitable for hangings, for which the harness is chiefly used.
A considerable number of weaves may be employed in binding the ground
or figure. Any two weaves can be used in conjunction for the ground and
figure which do not interfere with each other in the working.
[Illustration: FIG. 386.]
[Illustration: FIG. 387.]
[Illustration: FIG. 388.]
In addition to simple satin and twill weaves, Figs. 386 and 387 can be
used in conjunction, the figure being woven to either pattern. Fig. 388
will show that the two weaves do not interfere with each other--that
is, an end is never required to be lifted and left down at the same
time.
Figs. 389 and 390 can be used together, one forming the figure and the
other the ground.
The best way of compiling weaves to give variety to pressure harness
fabrics is to put the satin clots on paper first, and then to arrange a
pattern to fit in the empty squares.
[Illustration: FIG. 389.]
[Illustration: FIG. 390.]
[Illustration: FIG. 391.]
=Designing for Edleston’s Harness.=--When designing for the patent
harness, illustrated at Fig. 129, the sketch is put on point paper
in the ordinary manner, but it must be remembered in doing so that
the figure when woven will be on double the number of ends which it
apparently occupies on point paper.
[Illustration: FIG. 392.]
If the spot shown at Fig. 391 is put on point paper and woven in this
harness the effect shown at Fig. 392 will be obtained in the cloth. The
number of ends between the spots would only be nine on paper to give
the eighteen in the cloth.
It was pointed out in explaining the structure of this harness that
a weft figure could not be put upon a warp ground, as it is obvious
that not more than half the warp can be lifted at once, and the figure
must therefore be obtained by leaving the warp down. The designs are
confined to plain grounds, or weft figures may be thrown on weft satin
grounds, and twill or cord grounds may with advantage be used. The
method of putting eight-end satin on point paper is given at Fig. 130.
The principle of putting on paper any weave possible on this harness
will be understood by referring to the explanation given with the
illustration of the harness.
=Figured Lenos.=--Some of the most beautiful of all fabrics are
made with the leno harness, the combination of plain or floated figures
with the open and firm leno ground giving a fabric which is both
serviceable and effective. The structure of the harness has already
been explained with Fig. 145, and it has been shown how “four and four”
leno and a plain or floated weave can be combined.
[Illustration: FIG. 393.]
The method of putting the design on point paper for a figured leno
harness with 500 needles and 600 hooks (see Fig. 145) will be
understood from Fig. 393. This is a small portion of a design which
includes “four and four” leno, plain, and floated weft or warp. The
solid squares show the crossing threads lifted by the ground harness,
and the circles show the same ends lifted by the doup. There will thus
be four ends in a dent and four picks in a shed in the leno, and when
these are woven plain the contrast is very effective.
Two colours are necessary for putting the design on paper, and in
cutting the cards from the design the solid squares in the leno portion
will be cut opposite the third and fourth or seventh and eighth needles
in the ground set, whilst the circles in the design which show where
the doups are to be lifted will be cut opposite either the first or
tenth row of needles. In a ground weave of this kind both doups are
never lifted together, as the weave is easier when they are lifted
separately.
Some beautiful striped designs are made by using thick whip threads
to give a lace effect, and various fancy leno weaves can be made and
employed for giving variety to the effect.
If there are more than four picks in a shed on the leno it is often
necessary to lift one of the crossing ends when the standard ends are
lifting in order to prevent the threads from “slipping” or “fraying.”
[Illustration: FIG. 394.]
Fig. 394 will give a well-known two-doup effect, and other patterns may
be devised quite easily, the power of the harness being practically
unlimited.
Sometimes leno figures are woven on plain grounds, but the opposite is
the general rule. Floated figures are not much used, as the contrast
of the plain and leno is very effective, and is more serviceable than a
loose figure.
A very fair imitation of a four in a dent figured leno can be made by
using one doup stave in front of an ordinary Jacquard harness, and
crossing one end under three. By lifting the doup every other pick a
plain figure can be woven on the leno ground, one crossing three, on
the principle explained with Fig. 144.
[Illustration: FIG. 395.]
=Toiletings.=--In toilet quilts a raised plain figure is formed by
an extra warp from a separate beam interweaving with the plain cloth
where the ground of the design is required. Fig. 395 is a portion of a
design for a cloth of this kind. Every third end is an “extra” end, and
where the raised figure is required these ends are left down, but where
the ground of the design is required the extra ends interweave with
the plain cloth and bind it down. The tension of the extra warp causes
the figure to stick up more than would otherwise be the case. The
principle can be made to give innumerable effects by different methods
of introducing the extra warp, but the ends must not be left out of the
cloth for too long together, or they would be too loose at the back and
would be likely to catch. Fig. 396 is a section showing the binding of
the extra warp into the plain figuring cloth.
[Illustration: FIG. 396.]
The principle is well adapted for the production of large figures such
as are required on quilts and similar fabrics, owing to the fact that
only one-third of the warp threads are required to pass through the
Jacquard harness; the plain ends can be lifted by shafts.
In the better classes of toiletings two shuttles are used, and the
extra ends are woven plain at the back instead of hanging loose. The
principle is otherwise the same as in a one-shuttle toileting.
[Illustration: FIG. 397.]
In some quilts a padding weft is inserted between the face and back
cloth on the principle explained in Figs. 326-328. “Marseilles” quilts
are made in this manner. Fig. 397 will show how a padded figure is
formed, the dots represent the weft, and the principle of forming the
figure is the same as in Figs. 326 and 328.
When the padding picks are being put in, the face cloth is all lifted,
and the back cloth left down.
There are various other makes of quilts, of which the “Mitcheline”
type is extensively manufactured. These fabrics are characterized by
a raised figure of coarse texture upon a ground of comparatively fine
texture. Fig. 398 shows how this is effected.
[Illustration: FIG. 398.]
Two systems each of warp and weft are used, the warp being drawn in the
harness and reed as follows:--
one face end fine counts: (say white)
two figuring ends medium counts: (say brown).
The order of picking is--
two coarse figuring picks (white)
two fine ground picks (brown).
Two plain cloths are woven, one being white and the other brown, and
these are made to change places so as to form the desired figure in the
manner shown in Fig. 398.
The two cloths are bound together in both the figure and the ground.
When the white cloth is at the top, as in the first part of Fig. 398,
a ground pick is passed over a white face end under the float which
follows, and the binding is perfectly hidden. When the brown cloth is
at the top a white end is lifted, and as this is of a fine count and
the brown warp threads are rather closely set to the reed, the binding
is obscured.
A portion of a design of this weave is given at Fig. 399, the structure
of which will repay careful study along with the section at Fig. 398.
Twilled cloths are sometimes used for figuring on this double cloth
principle, and the binding can be much more easily effected, although
the weave is more expensive than double plain, if the same firmness is
desired. Fig. 400 is a section showing how the figure can be formed
from two twill cloths, and how the binding can be best effected. The
cloths in this example are of equal fineness.
[Illustration: REFERENCE.
[symbol] = White face warp-ends raised above coarse white figuring
picks.
[symbol] = Brown figuring warp-ends raised above fine brown ground
picks.
[symbol] = White face warp-ends raised above fine brown ground
picks, in the figure.
[symbol] = Brown figuring warp-ends raised above coarse white
figuring picks.
[symbol] = White face warp-ends raised above fine brown ground
picks, in the ground.
FIG. 399.]
[Illustration: FIG. 400.]
Fig. 401 is a design for this fabric, showing a small portion of both
ground and figure. The cloths are bound together once in every eight
threads.
[Illustration: FIG. 401.]
=Figured Weft Pile Velvets.=--When figuring with weft and pile,
the chief difficulty is the cutting of the fabric after weaving, owing
to the difficulty of keeping the knife-guide in the race when passing
from one portion of the figure to another across the ground.
A considerable quantity of fabrics had been made with velvet cord
figures--which are easy enough to cut--before it was found possible to
cut the real velvet figure. This was rendered possible by throwing the
short floats of pile weft to the back of the cloth at the edges of the
figure, and always moving in steps or races at the edges of the figure,
and in addition to this always keeping the end upon which the knife
runs, to the inside of each step. By throwing out the short floats the
chief difficulty was overcome, as the obstruction caused by these was
the chief cause of the knife and guide being thrown out when cutting.
These improvements were simultaneously devised by the writer and Mr. T.
Anderson, of Wyke, and a large quantity of cloth was turned out a few
years ago, but owing to the cottony appearance of the ground the demand
quickly fell away.
[Illustration: FIG. 402.]
Two large manufacturers took out a patent to include all figured weft
pile fabrics, but a thorough search could not have been made, as the
writer recently came across a heap of patterns woven on the same
principle, including the stepping in races, and also with a coloured
extra warp ground, which had been made at least before the year 1870.
The method of putting the designs on point paper is shown at Fig. 402.
The weave generally used is an ordinary E1 velvet with about 400 picks
per inch, woven in an 80 reed 2-60’s twist, 70’s weft. It will be seen
that the figure steps in twos at the edges, and that all floats less
than five are thrown to the back of the cloth by the small dots in the
design. The blanks represent the weft on the face, and the inside of
the step or race is arranged to come on the third, fifth, seventh ends,
and so on, these being the ends along which the knife runs. Where a
turn is made in the figure it must be on an odd number of ends in order
to keep the race in this position.
Other systems of making figured weft pile fabrics have been tried. One
of these was to use an extra warp at the back for binding the pile
picks where the ground is required, and binding the picks where the
figure is required, to the ordinary warp. When the pile is cut the
extra warp is torn away, pulling the pile with it where the ground of
the pattern occurs.
Another method is to weave the figure fast pile, and the ground loose
pile, and to brush the loose pile away at the back.
Velvet and leno stripes have been woven. As velvet requires a large
number of picks and leno a small number, there is a difficulty in
cutting the picks at the back of the leno stripe away. This can be
overcome by interweaving the picks to be taken away at the back of the
leno with some extra ends, and when the velvet stripe is cut, the back
cloth can be torn away quite easily.
=Solid Coloured Borders.=--In some fabrics, such as dhooties, the
borders are sometimes made with coloured warp and weft, and the middle
of the piece with white or grey yarns. The method of obtaining the
solid border is rather ingenious, and is as follows.
A coloured end is placed at each side of the warp, and this thread
hangs loose from the bobbin, so that not much force is required to pull
the thread into the border. The warp ends forming the border are on
separate staves from the ground ends, and lift so as to allow two picks
to go through each shed while the middle weaves ordinary plain cloth.
The coloured end A (Fig. 403) is lifted every other pick, and the
shuttle containing the white weft will pass round it, and as the shed
is not changed in the border ends, the coloured thread is taken into
the border, thus forming a solid coloured border on an ordinary grey or
white cloth. In the border, there will be two picks in a shed.
[Illustration: FIG. 403.]
[Illustration: FIG. 404.]
The point paper plan showing the difference in the shedding between the
border and the middle is given at Fig. 404. The coloured thread from
the bottom may be lifted by the plain staves.
=Direction of the Twist in Yarns.=--Warp yarns are usually twisted
so as to show the lines of the twist from right to left, and weft yarns
are twisted in the opposite direction. The reason for this is that when
the yarns are woven into cloth the lines of both warp and weft run in
the same direction, and the threads become embedded together as closely
as possible through the strands falling into each other. This is shown
at Fig. 405, where at A and B the warp and weft yarns are shown laid
side by side. At C the same yarns are shown as laid in the cloth, when
it will be seen that the lines of twist appear in the same direction,
and the threads have thus a chance of getting together as closely as
possible.
[Illustration: FIG. 405.]
If the weft is spun in the same direction as the warp, or “twist way,”
as it is termed, when woven the lines or strands appear in opposite
directions, and each thread has a tendency to be kept apart from the
others, and appears separately. This, if anything, makes the cloth
feel slightly thicker, and is preferred by many for certain purposes,
including some classes of printing cloths. The finer appearance is
obtained by the yarns spun in opposite directions.
[Illustration: FIG. 406.]
In twill and satin cloths, and similar fabrics, the direction of the
twist has a very important bearing upon the appearance of the fabric.
The finest and closest effect is obtained by using warp and weft yarns
spun in opposite directions, so that when woven the lines appear in the
same direction, and the direction of the twill should be opposite to
both. This is why one side of a twill cloth has a finer appearance than
the other, as the twill runs against the lines on one side, and with
the lines on the other side of the cloth, the former having the finer
appearance. Fig. 406 shows the yarns spun oppositely, and the twill
running in a direction opposite to the lines.
In sateen cloths there is a kind of twill in one direction, as shown in
Fig. 407, and the above principle applies to this as well as regular
twills.
[Illustration: FIG. 407.]
It often occurs that for printing and dyeing purposes the weft is
preferred spun “twist way,” and as the weft greatly predominates over
the warp, the direction of the twill should be contrary to the lines
of the weft. Not much difference is noticeable in the better makes
of cloth, but when there are few picks, a frayed appearance is often
produced if the direction of the twill is not reversed.
To keep the twill in a given direction, the twist may be spun “weft
way” to give the desired effect.
In very small twills, such as Jeannettes, a more decided twill is
obtained by using weft spun in the same way as the twist or warp yarns,
but in larger twills the best effect is obtained in the opposite
manner.
CHAPTER XII
_TEXTILE CALCULATIONS_
The numbers of cotton yarns are based upon the hank of 840 yards, the
number of hanks in 1 lb. being the “counts.”
It follows that if 840--the yards in one hank--be multiplied by the
counts, the result will be the yards in 1 lb. of that count.
Thus in 1 lb. of 30’s yarn there will be 840 × 30 = 25,200 yards, and
the yards in a pound of any count may be found in the same manner.
The counts of worsted yarns are based upon a hank of 560 yards, and the
number of hanks in 1 lb. Avoirdupois is the count of the yarn.
Linen yarns are based on a hank or lea of 300 yards, and the number of
these in 1 lb. is the count of the yarn.
Spun silk, which is the silk chiefly used in cotton fabrics for stripes
and headings, is numbered on the same system as cotton yarns. The
number of hanks of 840 yards in 1 lb. is the count of the yarn.
Net silks or thrown silks are numbered on an altogether different
system. The “skein” or hank is 520 yards, and the number of
deniers--533⅓ deniers = 1 oz.--which a skein weighs indicates the
number of the yarn. In silk manufacture the number of the yarn is
called the “size,” the word “count” being used to denote the closeness
of the reed.
Another system is used for silk yarns called the Manchester scale. This
is based upon the hank of 1,000 yards.
The number of drams which one such hank weighs is the “size” or number
of the yarn or thread.
In the former scale the yards per ounce may be found by multiplying the
yards in a hank by the deniers in one ounce, and dividing by the number
of deniers which a hank weighs.
The yards in an ounce of 40 denier silk will be--
deniers per oz. yards in skein
(533⅓ × 520)
--------------------- = 6933⅓ yards per oz.
40 deniers
In the Manchester silk scale the yards per ounce of a 4 dram silk may
be found by multiplying 1,000, the yards in a hank, by 16, the drams in
an ounce, and dividing by the number of drams which the hank weighs,
viz. 4; thus--
(1000 × 16)
----------- = 4000 yards per oz.
4
=Twofold Yarns= in cotton, worsted, and linen are numbered
according to the count of the single yarn, with the number of folds put
before it. Thus a 2-40’s yarn means that the yarn is composed of two
threads of 40’s single, making a twofold yarn of 20 hanks to the pound.
In spun silk the yarns are nearly always two or more fold, and the
number of the yarn always indicates the number of hanks in 1 lb. The
number of folds is usually written after the hanks per pound. Thus,
40’s-2 spun silk indicates that the yarn is 40 hanks to the pound, made
up of two threads of 80’s single.
It sometimes occurs in fancy yarns that threads of unequal thickness
are twisted together. If a 60’s thread and a 40’s thread are twisted
together, the count of the doubled thread will not be the same as if
two threads of 50 hanks to the pound, but will be something less than
this.
It is obvious that when the two threads are twisted together the
weight of a hank of the doubled thread will be 1/60 + 1/40 of a pound,
and by adding these fractions together the counts of the twofold yarn
may be obtained. Thus--
1 1 (3 + 2) 5
-- + -- = ------- = --- = 24’s counts.
40 60 120 120
Another method of obtaining the same result is to multiply the two
numbers together, and add them together, and divide one result by the
other. Thus--
60 60
40 40
--- ----
100) 2400 (24’s counts.
2400
----
If three or more unequal threads are twisted together the counts of the
resulting thread may be found by adding the fractions of a pound which
a hank of each count represents.
_Example._--Find the counts of a threefold thread composed of one
thread each of 10’s, 20’s and 60’s cotton.
1 1 1 (6 + 3 +1) 10 1
-- + -- + -- = ---------- = -- = -- or 6’s counts.
10 20 60 60 60 6
Some allowance must be made for the twisting of the threads, but this
will vary with the number of turns per inch in the yarn, and so is not
taken into account in the example.
If it is required to obtain the weight of each count in 100 lbs. of the
threefold yarn, the following is the method.
As one count is to the resulting count, so is the total weight to the
weight required of that yarn--
10 : 6 ∷ 100 : 60 lbs. of 10’s
20 : 6 ∷ 100 : 30 lbs. of 20’s
60 : 6 ∷ 100 : 10 lbs. of 60’s
----
100 lbs. Total.
=Reeds and Setts.=--The system of numbering reeds, now almost
universal in the cotton trade, is known as the Stockport or Manchester
count. The number of dents or splits per inch in the reed with two ends
in each dent is the basis of the system. If the reed has 30 dents per
inch, it is called a 60 reed, because if there are two ends in a dent
in the 30 dents there will be 60 ends per inch. The number of the reed
is always the same as the ends per inch in the reed, if the ends are
all two in a dent.
A 60 reed Stockport counts, if reeded three ends in a dent, will have
90 ends per inch, because a 60 reed has 30 dents per inch, and if there
are three in a dent, there will be 30 × 3 = 90 ends per inch.
Various other systems have been used, but are gradually giving way to
the simpler Stockport or Manchester system. Some of these are--
The Bolton count, in which the number of “beers” of 40 ends, or 20
dents, in 24¼ inches is the basis of the system.
The Blackburn count, in which the number of beers in 45 inches was the
basis. The beer, as above, being 20 dents, representing 40 ends in a
beer.
The Preston count was based on the number of beers in different widths.
The 6-4 count was based on the number of beers of 20
dents--representing 40 ends--in 58 inches.
The 9-8’s count was based on the number of beers in 44 inches.
The 4-4’s count was based on the beers in 39 inches.
The 7-8’s count was based on the beers in 34 inches.
The Scotch system is based on the number of dents in 37 inches. Thus in
a 2000 reed there will be 2000 dents in 37 inches, representing 4000
ends in that space.
The Bradford system is based on the number of beers of 40 ends in 36
inches. If there are 50 times 40 ends in 36 inches, it is a “50 sett.”
To find the number of ends per inch in a given sett, it is necessary to
multiply the sett by 40 and divide by 36, thus--
(50 sett × 40)
-------------- = 55-20/36 ends per inch.
36
=Quantity of Material in a Piece.=--To find the weight of warp and
weft of given counts in a piece, the total length of yarn in the piece
may be found, and divided by the yards in 1 lb. of the counts of yarn
used. This will give the weight in pounds. The following example will
make the principle quite clear:--
_Example._--Find the weight of warp and weft in a piece woven 30
inches wide in a 70 reed (Stockport) cloth 90 yards long, from 95
yards of warp, 80 picks per inch, the counts of twist or warp being
30’s, and counts of weft 40’s.
If the piece is 90 yards long, the length of warp used will be somewhat
in excess of this, as the warp in interlacing with the weft is bent out
of a straight line. The amount of “milling up,” as it is called, varies
according to the number of intersections in the pattern or weave of the
cloth, and with the counts of yarn used. It will also vary considerably
according to the elasticity of the yarn. Twofold yarns are more elastic
than single, and therefore will require a shorter length of yarn for a
given length of cloth.
In this example 95 yards of warp are used to weave a 90-yards piece, an
allowance of a little over 5 per cent.
In making the calculation for the weft it is necessary to take the
width in the reed, as this length of weft is used every pick. The cloth
will contract a little owing to the pull of the threads when woven,
and when calculating for a given width of cloth care must be taken to
calculate for the reed width and not the cloth width only.
In the present example the width in the reed is given, and so the cloth
will be somewhat narrower than this when woven.
TO FIND WEIGHT OF WARP.
840 yards in 1 hank 70 ends per inch
30 counts 30 inches in reed
----- ----
25200 yards in 1 lb. 2100 ends in warp
95 yards long
-----
10500
18900
------
199500 yards of twist in piece.
yards
199500
Therefore, weight of warp = ----- = 7 lbs. 14⅔ oz.
25200
yds. in 1 lb.
TO FIND WEIGHT OF WEFT.
840 yards in 1 hank 80 picks per inch
40 30 inches in reed
----- ----
33600 yards in 1 lb. 2400 inches of weft in 1 inch of cloth
36 inches in 1 yard
-----
14400
7200
-----
36)86400 inches of weft in 1 yard of cloth
-----
2400 yards of weft in 1 yard of cloth
90 yards length of piece
----
216000 yards of weft in piece.
216000
Therefore, weight of weft = ------ = 6 lbs. 6-6/7 oz.
33600
Weight of weft = 6 lbs. 6-6/7 oz.
Weight of warp = 7 lbs. 14⅔ oz.
In the weft calculation, the picks per inch multiplied by the width in
the reed in inches gives the inches of weft in one inch of cloth. This
multiplied by 36 will give the inches of weft in one yard of cloth, and
divided by 36, this gives the yards of weft in one yard of cloth. The
two 36’s may be left out, as it is obvious that the yards of weft in a
yard of cloth are the same as the inches of weft in an inch of cloth.
The formula to calculate the weight of warp in a piece is as follows:--
Inches in reed × length of warp in yards × ends per inch in reed
----------------------------------------------------------------
840 × counts
= =weight of warp=.
The formula for the weft is--
Inches in reed × length of piece in yards × picks per inch
----------------------------------------------------------
840 × counts
= =weight of weft=.
Working out the previous calculation in this manner, we get--
30 × 95 × 70
------------ = 7 lbs. 14⅔ oz. of warp.
840 × 30
30 × 90 × 80
------------ = 6 lbs. 6-6/7 oz. of weft.
840 × 40
If it is required to find the number of hanks, it is only necessary to
leave out the counts in the above formulæ. Thus we get--
Inches wide × length × ends per inch
------------------------------------ = hanks,
840
and using the figures in the previous example--
30 × 95 × 70
------------ = 237½ hanks of warp.
840
Before the actual cost of a piece of cloth can be calculated, it is
necessary to know the price to be paid the weaver. In Lancashire the
payment is made according to the list agreed upon by both employers
and employed. For plain cloths and twills a new uniform list has been
agreed upon, and this is now generally accepted. The following is the
new list:--
UNIFORM LIST OF PRICES FOR WEAVING.
=1. The Standard.=--The standard upon which this list is based is
an ordinary loom, 45 inches reed space, measured from the fork grate on
one side to the back board on the other, weaving cloth as follows:--
Width: 39, 40, 41 inches.
Reed: 60 reed, 2 ends in a dent, or 60 ends per inch.
Picks: 15 picks per quarter-inch, ascertained by arithmetical
calculation, with 1½ per cent. added for contraction.
Length: 100 yards, 36 inches to the yard, measured on the counter. Any
length of lap other than 36 inches to be paid in proportion.
Twist: 28’s, or any finer numbers.
Weft: 31’s to 100’s inclusive.
Price 2_s_. 6_d_., or 2_d_. per pick, per quarter-inch.
=2. Width of Looms.=--A 45-inch reed space loom being taken as the
standard, 1½ per cent. shall be added for each inch up to and including
51 inches; 2 per cent. from 51 to 56 inches; 2½ per cent. from 56 to 64
inches; and 3 per cent. from 64 to 72 inches.
1¼ per cent. shall be deducted for each inch from 45 to 37 inches
inclusive, and 1 per cent. from 37 to 24 inches, below which no further
deduction shall be made. For any fraction of an inch up to the half no
addition or deduction shall be made; but if over the half, the same
shall be paid as if it were a full inch.
All additions or deductions under this clause to be added to, or taken
from, the price of the standard loom 45 inches.
DEDUCTED FROM STANDARD.
+---------+-----------+
| Loom. |Percentage.|
+---------+-----------+
| Inches. | |
| 24 | 23 |
| 25 | 22 |
| 26 | 21 |
| 27 | 20 |
| 28 | 19 |
| 29 | 18 |
| 30 | 17 |
| 31 | 16 |
| 32 | 15 |
| 33 | 14 |
| 34 | 13 |
| 35 | 12 |
| 36 | 11 |
| 37 | 10 |
| 38 | 8¾ |
| 39 | 7½ |
| 40 | 6¼ |
| 41 | 5 |
| 42 | 3¾ |
| 43 | 2½ |
| 44 | 1¼ |
| 45 | standard |
+---------+-----------+
ADDED TO STANDARD.
+---------+-----------+
| Loom. |Percentage.|
+---------+-----------+
| Inches. | |
| 46 | 1½ |
| 47 | 3 |
| 48 | 4½ |
| 49 | 6 |
| 50 | 7½ |
| 51 | 9 |
| 52 | 11 |
| 53 | 13 |
| 54 | 15 |
| 55 | 17 |
| 56 | 19 |
| 57 | 21½ |
| 58 | 24 |
| 59 | 26½ |
| 60 | 29 |
| 61 | 31½ |
| 62 | 34 |
| 63 | 36½ |
| 64 | 39 |
| 65 | 42 |
| 66 | 45 |
| 67 | 48 |
| 68 | 51 |
| 69 | 54 |
| 70 | 57 |
| 71 | 60 |
| 72 | 63 |
+---------+-----------+
=3. Broader Cloth than admitted by Rule.=--All looms shall be
allowed to weave to within 4 inches of the reed space; but whenever the
difference between the width of cloth and the reed space is less than
4 inches, it shall be paid as if the loom were 1 inch broader: and if
less than 3 inches, as if it were 2½ inches broader.
=4. Allowance for Cloth 7 to 15 inches narrower than the Reed
Space.=--When the cloth is from 7 to 15 inches narrower than the
reed space of the loom in which it is woven, a deduction in accordance
with the following table shall be made:--
DEDUCTIONS FOR NARROW CLOTH.
+------+------+-------+
|Reed |Cloth.| Per |
|space.| | cent. |
+------+------+-------+
| 72 | 65 | 1·38 |
| 72 | 64 | 2·76 |
| 72 | 63 | 4·14 |
| 72 | 62 | 5·52 |
| 72 | 61 | 6·9 |
| 72 | 60 | 8·28 |
| 72 | 59 | 9·66 |
| 72 | 58 | 11·04 |
| 72 | 57 | 12·19 |
| 71 | 64 | 1·41 |
| 71 | 63 | 2·81 |
| 71 | 62 | 4·22 |
| 71 | 61 | 5·62 |
| 71 | 60 | 7·03 |
| 71 | 59 | 8·44 |
| 71 | 58 | 9·84 |
| 71 | 57 | 11·02 |
| 71 | 56 | 12·19 |
| 70 | 63 | 1·43 |
| 70 | 62 | 2·87 |
| 70 | 61 | 4·3 |
| 70 | 60 | 5·73 |
| 70 | 59 | 7·17 |
| 70 | 58 | 8·6 |
| 70 | 57 | 9·79 |
| 70 | 56 | 10·99 |
| 70 | 55 | 12·18 |
| 69 | 62 | 1·46 |
| 69 | 61 | 2·92 |
| 69 | 60 | 4·38 |
| 69 | 59 | 5·84 |
| 69 | 58 | 7·31 |
| 69 | 57 | 8·52 |
| 69 | 56 | 9·74 |
| 69 | 55 | 10·96 |
| 69 | 54 | 12·18 |
| 68 | 61 | 1·49 |
| 68 | 60 | 2·98 |
| 68 | 59 | 4·47 |
| 68 | 58 | 5·96 |
| 68 | 57 | 7·2 |
| 68 | 56 | 8·44 |
| 68 | 55 | 9·69 |
| 68 | 54 | 10·93 |
| 68 | 53 | 12·17 |
| 67 | 60 | 1·52 |
| 67 | 59 | 3·04 |
| 67 | 58 | 4·56 |
| 67 | 57 | 5·83 |
| 67 | 56 | 7·09 |
| 67 | 55 | 8·36 |
| 67 | 54 | 9·63 |
| 67 | 53 | 10·9 |
| 67 | 52 | 12·16 |
| 66 | 59 | 1·55 |
| 66 | 58 | 3·1 |
| 66 | 56 | 5·69 |
| 66 | 55 | 6·98 |
| 66 | 54 | 8·28 |
| 66 | 53 | 9·57 |
| 66 | 52 | 10·86 |
| 66 | 51 | 12·16 |
| 65 | 58 | 1·58 |
| 65 | 57 | 2·91 |
| 65 | 56 | 4·23 |
| 65 | 55 | 5·55 |
| 65 | 54 | 6·87 |
| 65 | 53 | 8·19 |
| 65 | 52 | 9·51 |
| 65 | 51 | 10·83 |
| 65 | 50 | 12·15 |
| 64 | 57 | 1·35 |
| 64 | 56 | 2·7 |
| 64 | 55 | 4·05 |
| 64 | 54 | 5·4 |
| 64 | 53 | 6·74 |
| 64 | 52 | 8·09 |
| 64 | 51 | 9·44 |
| 64 | 50 | 10·79 |
| 64 | 49 | 11·87 |
| 63 | 56 | 1·37 |
| 63 | 55 | 2·75 |
| 63 | 54 | 4·12 |
| 63 | 53 | 5·49 |
| 63 | 52 | 6·87 |
| 63 | 51 | 8·24 |
| 63 | 50 | 9·62 |
| 63 | 49 | 10·71 |
| 63 | 48 | 11·81 |
| 62 | 55 | 1·4 |
| 62 | 54 | 2·8 |
| 62 | 53 | 4·2 |
| 62 | 52 | 5·6 |
| 62 | 51 | 7·0 |
| 62 | 50 | 8·4 |
| 62 | 49 | 9·51 |
| 62 | 47 | 11·75 |
| 61 | 54 | 1·43 |
| 61 | 53 | 2·85 |
| 61 | 52 | 4·28 |
| 61 | 51 | 5·7 |
| 61 | 50 | 7·13 |
| 61 | 49 | 8·27 |
| 61 | 48 | 9·41 |
| 61 | 47 | 10·55 |
| 61 | 46 | 11·69 |
| 60 | 53 | 1·45 |
| 60 | 52 | 2·91 |
| 60 | 51 | 4·36 |
| 60 | 50 | 5·81 |
| 60 | 49 | 6·98 |
| 60 | 48 | 8·14 |
| 60 | 47 | 9·3 |
| 60 | 46 | 10·47 |
| 60 | 45 | 11·63 |
| 59 | 52 | 1·48 |
| 59 | 51 | 2·96 |
| 59 | 50 | 4·45 |
| 59 | 49 | 5·63 |
| 59 | 48 | 6·82 |
| 59 | 47 | 8·0 |
| 59 | 46 | 9·19 |
| 59 | 45 | 10·38 |
| 59 | 44 | 11·26 |
| 58 | 51 | 1·51 |
| 58 | 50 | 3·02 |
| 58 | 49 | 4·23 |
| 58 | 48 | 5·44 |
| 58 | 47 | 6·65 |
| 58 | 46 | 7·86 |
| 58 | 45 | 9·07 |
| 58 | 44 | 9·98 |
| 58 | 43 | 10·89 |
| 57 | 50 | 1·54 |
| 57 | 49 | 2·78 |
| 57 | 48 | 4·01 |
| 57 | 47 | 5·25 |
| 57 | 46 | 6·48 |
| 57 | 45 | 7·72 |
| 57 | 44 | 8·64 |
| 57 | 43 | 9·57 |
| 57 | 42 | 10·49 |
| 56 | 49 | 1·26 |
| 56 | 48 | 2·52 |
| 56 | 47 | 3·78 |
| 56 | 46 | 5·04 |
| 56 | 45 | 6·3 |
| 56 | 44 | 7·25 |
| 56 | 43 | 8·19 |
| 56 | 42 | 9·14 |
| 56 | 41 | 10·08 |
| 55 | 48 | 1·28 |
| 55 | 47 | 2·56 |
| 55 | 46 | 3·85 |
| 55 | 45 | 5·13 |
| 55 | 44 | 6·09 |
| 55 | 43 | 7·05 |
| 55 | 42 | 8·01 |
| 55 | 41 | 8·97 |
| 55 | 40 | 9·94 |
| 54 | 47 | 1·3 |
| 54 | 46 | 2·61 |
| 54 | 45 | 3·91 |
| 54 | 44 | 4·89 |
| 54 | 43 | 5·87 |
| 54 | 42 | 6·85 |
| 54 | 41 | 7·83 |
| 54 | 40 | 8·8 |
| 54 | 39 | 9·78 |
| 53 | 46 | 1·33 |
| 53 | 45 | 2·65 |
| 53 | 44 | 3·65 |
| 53 | 43 | 4·65 |
| 53 | 42 | 5·64 |
| 53 | 41 | 6·64 |
| 53 | 40 | 7·63 |
| 53 | 39 | 8·63 |
| 53 | 38 | 9·42 |
| 52 | 45 | 1·35 |
| 52 | 44 | 2·36 |
| 52 | 43 | 3·38 |
| 52 | 42 | 4·39 |
| 52 | 41 | 5·41 |
| 52 | 40 | 6·42 |
| 52 | 39 | 7·43 |
| 52 | 38 | 8·28 |
| 52 | 37 | 9·12 |
| 51 | 44 | 1·03 |
| 51 | 43 | 2·06 |
| 51 | 42 | 3·1 |
| 51 | 41 | 4·13 |
| 51 | 40 | 5·16 |
| 51 | 39 | 6·19 |
| 51 | 38 | 7·05 |
| 51 | 37 | 7·91 |
| 51 | 36 | 8·77 |
| 50 | 43 | 1·05 |
| 50 | 42 | 2·09 |
| 50 | 41 | 3·14 |
| 50 | 40 | 4·19 |
| 50 | 39 | 5·23 |
| 50 | 38 | 6·1 |
| 50 | 37 | 6·98 |
| 50 | 36 | 7·85 |
| 50 | 35 | 8·72 |
| 49 | 42 | 1·06 |
| 49 | 41 | 2·12 |
| 49 | 40 | 3·18 |
| 49 | 39 | 4·25 |
| 49 | 38 | 5·13 |
| 49 | 37 | 6·01 |
| 49 | 36 | 6·9 |
| 49 | 35 | 7·78 |
| 49 | 34 | 8·67 |
| 48 | 41 | 1·08 |
| 48 | 40 | 2·15 |
| 48 | 39 | 3·23 |
| 48 | 38 | 4·13 |
| 48 | 37 | 5·02 |
| 48 | 36 | 5·92 |
| 48 | 35 | 6·82 |
| 48 | 34 | 7·72 |
| 48 | 33 | 8·61 |
| 47 | 40 | 1·09 |
| 47 | 39 | 2·18 |
| 47 | 38 | 3·09 |
| 47 | 37 | 4·0 |
| 47 | 36 | 4·91 |
| 47 | 35 | 5·83 |
| 47 | 34 | 6·74 |
| 47 | 33 | 7·65 |
| 47 | 32 | 8·56 |
| 46 | 39 | 1·11 |
| 46 | 38 | 2·03 |
| 46 | 37 | 2·96 |
| 46 | 36 | 3·88 |
| 46 | 35 | 4·8 |
| 46 | 34 | 5·73 |
| 46 | 33 | 6·65 |
| 46 | 32 | 7·57 |
| 46 | 31 | 8·5 |
| 45 | 38 | 0·94 |
| 45 | 37 | 1·87 |
| 45 | 36 | 2·81 |
| 45 | 35 | 3·75 |
| 45 | 34 | 4·69 |
| 45 | 33 | 5·62 |
| 45 | 32 | 6·56 |
| 45 | 31 | 7·5 |
| 45 | 30 | 8·25 |
| 44 | 37 | 0·95 |
| 44 | 36 | 1·9 |
| 44 | 35 | 2·85 |
| 44 | 34 | 3·80 |
| 44 | 33 | 4·75 |
| 44 | 32 | 5·70 |
| 44 | 31 | 6·65 |
| 44 | 30 | 7·41 |
| 44 | 29 | 8·16 |
| 43 | 36 | 0·96 |
| 43 | 35 | 1·92 |
| 43 | 34 | 2·88 |
| 43 | 33 | 3·77 |
| 43 | 32 | 4·81 |
| 43 | 31 | 5·77 |
| 43 | 30 | 6·54 |
| 43 | 29 | 7·31 |
| 43 | 28 | 8·08 |
| 42 | 35 | 0·97 |
| 42 | 34 | 1·95 |
| 42 | 33 | 2·92 |
| 42 | 32 | 3·9 |
| 42 | 31 | 4·87 |
| 42 | 30 | 5·65 |
| 42 | 29 | 6·43 |
| 42 | 28 | 7·21 |
| 42 | 27 | 7·99 |
| 41 | 34 | 0·99 |
| 41 | 33 | 1·97 |
| 41 | 32 | 2·96 |
| 41 | 31 | 3·95 |
| 41 | 30 | 4·74 |
| 41 | 29 | 5·52 |
| 41 | 28 | 6·32 |
| 41 | 27 | 7·11 |
| 41 | 26 | 7·89 |
| 40 | 33 | 1·0 |
| 40 | 32 | 2·0 |
| 40 | 31 | 3·0 |
| 40 | 30 | 3·8 |
| 40 | 29 | 4·6 |
| 40 | 28 | 5·4 |
| 40 | 27 | 6·2 |
| 40 | 26 | 7·0 |
| 40 | 25 | 7·8 |
| 39 | 32 | 1·01 |
| 39 | 31 | 2·03 |
| 39 | 30 | 2·84 |
| 39 | 29 | 3·65 |
| 39 | 28 | 4·46 |
| 39 | 27 | 5·27 |
| 39 | 26 | 6·08 |
| 39 | 25 | 6·89 |
| 39 | 24 | 7·7 |
| 38 | 31 | 1·03 |
| 38 | 30 | 1·85 |
| 38 | 29 | 2·67 |
| 38 | 28 | 3·49 |
| 38 | 27 | 4·32 |
| 38 | 26 | 5·14 |
| 38 | 25 | 5·96 |
| 38 | 24 | 6·78 |
| 38 | 23 | 7·60 |
| 37 | 30 | 0·83 |
| 37 | 29 | 1·67 |
| 37 | 28 | 2·5 |
| 37 | 27 | 3·33 |
| 37 | 26 | 4·17 |
| 37 | 25 | 5·0 |
| 37 | 24 | 5·83 |
| 37 | 23 | 6·67 |
| 37 | 22 | 7·5 |
| 36 | 29 | 0·84 |
| 36 | 28 | 1·69 |
| 36 | 27 | 2·53 |
| 36 | 26 | 3·37 |
| 36 | 25 | 4·21 |
| 36 | 24 | 5·06 |
| 36 | 23 | 5·9 |
| 36 | 22 | 6·74 |
| 36 | 21 | 7·58 |
| 35 | 28 | 0·85 |
| 35 | 27 | 1·7 |
| 35 | 26 | 2·56 |
| 35 | 25 | 3·41 |
| 35 | 24 | 4·26 |
| 35 | 23 | 5·11 |
| 35 | 22 | 5·97 |
| 35 | 21 | 6·82 |
| 35 | 20 | 7·67 |
| 34 | 27 | 0·86 |
| 34 | 26 | 1·72 |
| 34 | 25 | 2·59 |
| 34 | 24 | 3·45 |
| 34 | 23 | 4·31 |
| 34 | 22 | 5·17 |
| 34 | 21 | 6·03 |
| 34 | 20 | 6·9 |
| 34 | 19 | 7·76 |
| 33 | 26 | 0·87 |
| 33 | 25 | 1·74 |
| 33 | 24 | 2·62 |
| 33 | 23 | 3·49 |
| 33 | 22 | 4·36 |
| 33 | 21 | 5·23 |
| 33 | 20 | 6·1 |
| 33 | 19 | 6·98 |
| 33 | 18 | 7·85 |
| 32 | 25 | 0·88 |
| 32 | 24 | 1·76 |
| 32 | 23 | 2·65 |
| 32 | 22 | 3·53 |
| 32 | 21 | 4·41 |
| 32 | 20 | 5·29 |
| 32 | 19 | 6·18 |
| 32 | 18 | 7·06 |
| 31 | 24 | 0·89 |
| 31 | 23 | 1·79 |
| 31 | 22 | 2·68 |
| 31 | 21 | 3·57 |
| 31 | 20 | 4·46 |
| 31 | 19 | 5·36 |
| 31 | 18 | 6·25 |
| 30 | 23 | 0·9 |
| 30 | 22 | 1·81 |
| 30 | 21 | 2·71 |
| 30 | 20 | 3·61 |
| 30 | 19 | 4·52 |
| 30 | 18 | 5·42 |
| 29 | 22 | 0·91 |
| 29 | 21 | 1·83 |
| 29 | 20 | 2·74 |
| 29 | 19 | 3·66 |
| 29 | 18 | 4·57 |
| 28 | 21 | 0·93 |
| 28 | 20 | 1·85 |
| 28 | 19 | 2·78 |
| 28 | 18 | 3·7 |
| 27 | 20 | 0·94 |
| 27 | 19 | 1·87 |
| 27 | 18 | 2·81 |
| 26 | 19 | 0·95 |
| 26 | 18 | 1·9 |
| 25 | 18 | 0·96 |
+------+------+-------+
No further deduction shall be made when cloth is more than 15 inches
narrower than the reed space, or when cloth is narrower than 18 inches.
Fractions of an inch not to be recognized under this clause.
=5. Reeds.=--A 60 reed being taken as the standard, ¾ per cent. shall
be deducted for every two ends or counts of reed from 60 to 50, but
no deduction shall be made below 50. ¾ per cent. shall be added for
every two ends or counts of reed from 60 to 68, 1 per cent. from 68 to
100; 1½ per cent. from 100 to 110; and 2 per cent. from 110 to 132. All
additions or deductions under this clause to be added to or deducted
from the price of the standard 60 reed.
+--------------------+
| Deductions |
| from standard. |
+--------+-----------+
|Count of|Percentage.|
| reed. | |
+--------+-----------+
| 50 | 3¾ |
| 52 | 3 |
| 54 | 2¼ |
| 56 | 1½ |
| 58 | ¾ |
| 60 | standard |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
| | |
+--------+-----------+
+------------------------------------------+
| Additions to standard. |
| |
+--------+-----------+
|Count of|Percentage.|
| reed. | |
+--------+-----------+
| 62 | ¾ |
| 64 | 1½ |
| 66 | 2¼ |
| 68 | 3 |
| 70 | 4 |
| 72 | 5 |
| 74 | 6 |
| 76 | 7 |
| 78 | 8 |
| 80 | 9 |
| 82 | 10 |
| 84 | 11 |
| 86 | 12 |
| 88 | 13 |
| 90 | 14 |
| 92 | 15 |
| 94 | 16 |
| 96 | 17 |
| 98 | 18 |
| 100 | 19 |
| 102 | 20½ |
| 104 | 22 |
| 106 | 23½ |
| 108 | 25 |
| 110 | 26½ |
| 112 | 28½ |
| 114 | 30½ |
| 116 | 32½ |
| 118 | 34½ |
| 120 | 36½ |
| 122 | 38½ |
| 124 | 40½ |
| 126 | 42½ |
| 128 | 44½ |
| 130 | 46½ |
| 132 | 48½ |
+--------+-----------+
=6. Picks.=--_Low Picks._--An addition of 1 per cent. shall be
made for each pick or fraction of a pick below 11, thus:--
Below 11 to and including 10, 1 per cent.
„ 10 „ „ 9, 2 „
„ 9 „ „ 8, 3 „
„ 8 „ „ 7, 4 „
and so on, adding 1 per cent. for each pick or fraction of a pick.
_High Picks._--An addition of 1 per cent. shall be made for each pick
whenever they exceed the following:--
Weft below 26’s. when picks exceed 16
„ 26’s to 39’s inclusive „ „ „ 18
„ 40’s and above „ „ „ 20
In making additions for high picks, any fraction of a pick less than
the half shall not have any allowance; exactly the half-pick shall have
½ per cent. added; and any fraction over the half-pick shall have 1 per
cent. added.
=7. Twist.=--The standard being 28’s or finer, the following
additions shall be made when coarser twist is woven in the following
reeds:--
Below 28’s to 20’s in 64 to 67 reed inclusive, 1 per cent.
„ „ 68 „ 71 „ „ 2 „
„ „ 72 „ 75 „ „ 3 „
Below 20’s to 14’s in 56 „ 59 „ „ 1 „
„ „ 60 „ 63 „ „ 2 „
„ „ 64 „ 67 „ „ 3 „
and so on at the same rate.
When twist is woven in coarser reeds no addition shall be made.
=8. Weft.=--_Ordinary Pin Cops._--The standard being 31’s to
100’s, both inclusive, shall be reckoned equal. Above 100’s 1 per cent.
shall be added for every 10 hanks or fraction thereof.
In lower numbers than 31’s the following additions shall be made:--
For 30’s add 1 per cent.
„ 29’s, 28’s, add 2 per cent.
„ 27’s, 26’s, „ 3 „
„ 25’s, 24’s, „ 4½ „
„ 23’s, 22’s, „ 6½ „
„ 21’s, 20’s, „ 8 „
„ 19’s, 18’s, „ 10½ „
„ 17’s, 16’s, „ 13 „
„ 15’s, 14’s, „ 16 „
_Large Cops._--When weft of the following counts is spun into large
cops, so that there are not more than nineteen cops to the lb., the
following additions shall be made in place of the allowance provided
for pin cops in the preceding table:--
For 29’s, 28’s, add 1 per cent.
„ 27’s, 26’s, „ 2 „
„ 25’s, 24’s, 23’s, „ 3 „
„ 22’s, 21’s, 20’s, „ 4½ „
„ 19’s, 18’s, „ 6 „
„ 17’s, 16’s, „ 8 „
„ 15’s, 14’s, „ 10 „
=9. Four-stave Twills.=--_Low Picks._--In four-stave twills an
addition of 1 per cent. for each pick or fraction thereof below the
picks mentioned in the following table shall be made when using weft as
follows:--
Below 26’s, the addition shall begin at 13
26’s to 39’s, inclusive, „ „ „ 14
40’s and above, „ „ „ 15
_High Picks._--When using weft--
Below 26’s, the addition for high picks shall begin at 21
26’s to 39’s, inclusive, „ „ „ „ „ „ 22
40’s and above, „ „ „ „ „ „ 23
In making additions for high picks any fraction of a pick less than the
half shall not have any allowance; exactly the half-pick shall have ½
per cent. added, and any fraction over the half shall have the full 1
per cent. added.
=10. Splits.=--The following additions shall be made for splits:--
One split uncut, add 5 per cent.
Two splits „ „ 7½ „
Empty dents shall not be considered splits.
=11.= All the foregoing additions and deductions shall be made
separately.
This list is subject to a deduction of 10 per cent.
* * * * *
For fancy cloths the CHORLEY LIST, 1886, is the one most commonly used.
This is as follows:--
=Double-Lift Jacquards.=--To be paid the following over plain
cloth prices:--
For cloths with plain grounds, 30 per cent.
For cloths with satin grounds, 25 „
Brocades, damasks, and crammed stripes with three or more ends in a
dent, to be paid for by the number of ends per inch.
Picks 18 to 30 per quarter inch, 1 per cent. per pick; from 30 to 40
picks, ¾ per cent.; all above 40 picks, ½ per cent. instead of 1 per
cent.
Lace brocades, 5 per cent. extra.
Single-lift jacquards to be paid 10 per cent. about double-lift
machines.
The above applies to Jacquards only.
=Dobby and Tappet Looms (except Satins).=--To be paid the
following above plain cloth prices--
Up to and including--
4 staves 12 per cent.
5 „ 13 „
6 „ 14 „
7 „ 15 „
8 „ 16 „
9 „ 17 „
10 „ 18 „
11 „ 19 „
12 „ 20 „
13 „ 21 „
14 „ 22 „
15 „ 23 „
16 „ 24 „
17 „ 25 „
18 „ 26 „
19 „ 27 „
20 „ 28 „
Stripes and other cloths with three or more ends in a dent to be paid
for by the number of ends per inch.
In single-shuttle checks, handkerchiefs, and all special classes of
goods in which more than one pick is put in one shed, all lost picks
shall be counted.
Plain handkerchiefs, 72 reeds and below, to be paid 5 per cent. extra.
Single-shuttle cord checks with more than two picks in one shed to be
paid 2½ per cent. less.
Lace stripes and other special classes of goods shall be paid extra as
per special arrangement to be agreed upon by Employers’ and Operatives’
Associations.
The following example will show the method of calculating the price to
be paid for weaving under the Uniform List:--
_Example._--Find the weaving of a 44-inch cloth, 40 yards long,
woven in a loom 48-inch reed space, 92 reed, 30 picks per
quarter-inch, 40’s twist, 60’s weft.
2_d._ per pick standard
·09 = 4½ per cent. added for reed space
-----
2·09
·3135 = 15 per cent. added for reed
------
2·4035 = price per pick, 100 yards, with standard picks
30 picks
-------
72·1050 = price for 30 picks 100 yards
40 yards
----------
100)2884·2000
----------
28·84200 = price for 40 yards
2·884200 = 10 per cent. added for high picks
---------
31·726200 Total.
From this must be deducted 10 per cent., as per agreement, which will
give 28·5535 pence as the actual price to be paid for weaving this
piece of cloth.
The following example includes the allowance for narrow cloth woven in
broad looms:--
_Example._--Find the weaving price for 38-inch cloth woven in a
48-inch reed space loom, 50 reed, 507 dividend, 50 change wheel, 75
yards long, 32’s twist, 36’s weft.
2_d._ per pick standard
·09 = 4½ per cent. added for reed space
---
2·09
·078375 = 3·75 per cent. deducted for reed
--------
2·011625 = price per pick, 100 yards, 50 reed, 48-inch loom.
507
--- = 10·14 picks per quarter inch.
50
2·0116 × 10·14 picks × 75 yards
-------------------------------
100 yards
= 15·283218 price for 75 yards
·152832 = 1 per cent. added for pick
---------
15·436050
·637508 = 4·13 per cent. deducted for narrow cloth
---------
14·798542 = price per list
1·4798542 = 10 per cent. deduction
----------
13·3186878 = net price.
In making the additions and deductions it is important that they should
be made in the above order.
=The Cost of a Piece of Cloth.=--Besides the cost of material
and the weaving wage, the expenses of the manufacturer must be taken
into account. When a manufacturer makes only one kind of cloth, his
expenses will obviously not be so proportionately great as another
manufacturer’s who only takes a single order of a particular make. The
expenses also vary with the district and distance from the market, and
with other circumstances.
A manufacturer knows from experience exactly what amount of expenses to
allow in different classes of fabrics in his own case, and in quoting
prices for plain or fancy cloths he usually includes under the term
“expenses” all the items of cost from the carriage of the yarn to the
delivery of the cloth, including winding, warping, sizing, waste, and
other fixed expenses in the mill.
The expenses are usually calculated in proportion to the weaving wage,
and a manufacturer quotes “double weaving” or “three times weaving,”
according to the class of fabric in question.
The following example will illustrate the principle of estimating the
cost of a piece.
Find the cost of a piece, 34 inches full, 75 yards s.s. (short stick),
19 × 18, 32’s/40’s. Twist at 7_d._ per lb., weft at 7½_d._ per lb.
Weaving 2_s._ Expenses equal to weaving.
The 34-inch cloth would stand, say, 36 inches in the reed. The 75-yards
cloth, “short stick,” or 36 inches to the yard, will require, say, 78
yards of warp.
A cloth counting 19 × 18, nominal, is usually woven in a 68 or 70 reed,
and the picks per inch will be about 66 or 67 actually.
Assuming that the cloth stands 36 inches in a 70 reed, and the picks
per inch are 67, we get--
36 inches × 78 yards × 70 reed × 7_d._
------------------------------------- = 51.188_d._, cost of twist,
840 × 32’s
and
36 inches × 75 yards × 67 picks × 7½_d._
----------------------------------------- = 40.38_d._, cost of weft.
840 × 40’s
_d._
51.188 cost of twist
40.38 cost of weft
24.00 weaving wage
24.00 expenses
-------
139.568 cost of piece = 11_s._ 7½_d._
The amount allowed for expenses in the preceding example is perhaps
sufficient for most cloths woven on dobbies, but more is required for
jacquard-woven fabrics.
If 11_s._ 7½_d._ is quoted for the above cloth, the price is said to be
based on “double weaving.”
For jacquard fabrics the price is usually based on 2½ to 3 times
weaving, and in special cases, such as new styles, an extra profit is
put upon the 3-times weaving.
Sometimes the expenses are said to be 5 or 10 per cent. more than
weaving. If the weaving wage were 2_s._ 6_d._, and the expenses 10 per
cent. more than weaving, the expenses would be 2_s._ 9_d._
=Contraction.=--The length of warp required to weave a piece of
a given length will vary with the pattern or weave of the cloth, and
depends also on the elasticity of the yarn and the counts of both warp
and weft. Owing to this difference in the elasticity of various classes
of yarns, and the variation in the elasticity of the same yarn at
different degrees of tension, it is impossible to lay down rules for
the calculation of the exact warp length for a given length of piece,
or for the exact width in the reed for a required width of piece.
The length of warp required can only be obtained with exactness from
experience, especially in fancy cloths.
As previously stated, twofold yarns are more elastic than single;
indeed, with some kinds of twofold American yarns, such as are used in
velvets, the percentage of contraction becomes less with an increase in
the number of picks, owing to the increase of tension upon the yarn,
which causes it to stretch more.
Roughly, the amount of contraction to allow in the warp can be
obtained by taking into account the counts of weft and the number of
intersections which the warp makes with the weft. The thicker the
counts of weft the more the warp will be bent out of a straight line,
also with an increase in the number of picks the amount of take-up or
contraction will increase. This does not vary in a regular manner, as
the angle which the warp makes in bending over the weft changes with
any variation in the picks. Furthermore, the greater the tension on the
warp yarn the more it will stretch, and also the more it will compress
the weft at the point of intersection.
A rough estimate only can therefore be made if there is no previous
experience in the same class of goods to guide the manufacturer.
A method of roughly estimating the percentage of milling-up of the warp
is to multiply the intersections of the warp per inch by a number found
by experience to give the right result, and to divide this product by
the counts of weft used.
For rather heavily picked cloths the multiplier 4 gives a fairly
accurate result, and in cloths with a medium number of picks and medium
counts the multiplier 3 will be used. In some classes of goods the
multiplier requires to be 5; but when a correct multiplier is found
for a certain class of goods, it will serve for changes in that class.
The system is certainly not accurate in all cases, but it embraces
roughly the different causes which alter the percentage of contraction
or milling-up in the warp, and is therefore of some use in practice.
_Example._--Find the length of warp required to weave a piece of
5-stave satin 94 yards long (36 inches to the yard), 94 reed, 180
picks per inch, 60’s twist, 70’s weft.
The number of intersections per inch will be two-fifths of the
number of picks, as the warp intersects twice every five picks or
pattern.
∴180 × ⅖ = 72 intersections per inch;
and 72 × 4
----------- = 4 per cent. contraction.
70’s counts
The length of warp required to weave the 94 yards piece would
therefore, roughly, be 98 yards.
In a plain cloth the contraction is much more than in a satin, and the
percentage is greater in heavily picked cloths than light ones.
In a plain cloth of, say, 120 picks per inch, 60’s twist, 70’s weft,
the percentage of take-up will roughly be as follows:--
Intersections per inch = 120
4
---
70)480(6-6/7 per cent. contraction.
420
---
60
In a plain cloth the warp intersects every pick, and so the
intersections per inch are the same as the ends per inch. In a “two
and two” twill the warp intersects twice in four picks, and the
intersections per inch will be one-half the picks.
In more medium cloths the multiplier 3 is used; as, for example:--
Find percentage of contraction in a piece of plain cloth woven with 60
picks per inch, 32’s twist, 40’s weft.
60 × 3
----------- = 4½ per cent.
40’s counts
In fancy cloths experience is the only guide as to the warp length
required, but in striped cloths and similar fabrics woven from one beam
the contraction of the whole will be that of the tightest weave in the
pattern.
In a fabric in which there are only a _few_ plain ends in the pattern,
the other ends being loosely interwoven, it does not follow that the
take-up will be as much as in a plain cloth, as the plain ends will
compress the weft more at the point of intersection than could occur if
_all_ the ends were weaving plain.
=Testing Yarn.=--It often occurs that only a short length of yarn
is available for being weighted when it is required to test it for the
counts. If it is required to test the weft in a piece of grey cloth
it is usual to take out of the cloth 120 yards, or one “lea.” This
is one-seventh of a hank, and therefore if the weight of 120 yards
is divided into 1,000 grains--the one-seventh part of a pound--the
quotient will be the counts of the yarn. The reason of this will be
obvious when it is remembered that if the weight of one hank is divided
into 7000 grains, or 1 lb., the result is the number of hanks in 1 lb.,
or the counts.
The counts are based upon the number of hanks in 1 lb. avoirdupois,
and as this weight is not suitable for weighing small quantities, it
is necessary to weigh them in Troy weight. As nearly as possible 7000
grains Troy = 1 lb. avoirdupois.
_Example._--If 120 yards of cotton weft weighs 20 grains, what
counts is it?
1000
--------- = 50’s counts.
20 grains
If it is required to know the number of grains which 120 yards of
any count should weigh, the method of procedure is the reverse of the
foregoing.
_Example._--How many grains should 120 yards of 40’s yarn weigh?
1000 grains
----------- = 25 grains.
40’s counts
When testing the counts of cops, it is usual to wrap two, three, or
four cops, in order to arrive at a more satisfactory test.
If two leas, or two-sevenths of a hank, are weighed, the counts can be
obtained by dividing the weight into 2000 grains, or two-sevenths of 1
lb. If three leas, or 360 yards, are weighed, divide the weight into
3000 grains, and the result is the counts. If 480 yards are weighed,
the dividend is 4000; if 600 yards, or five leas, are weighed, the
dividend will be 5000; if six leas, or 720 yards, are weighed, the
dividend is 6000; and when seven leas, or one hank, is weighed, the
dividend will be 7000 grains, or 1 lb.
As it takes a considerable time to take 120 yards of weft out of
a piece, a shorter length is often weighed and the counts found
therefrom. A balance is extensively used which registers the counts
when twenty yards of yarn are put upon the pointer. This is a very
useful, though not always accurate, method.
When any odd length of yarn is weighed, the counts may be obtained by
proportion, thus--
If 34 yards of yarn have been found to weigh 8 grains, what count is it?
The yards in 1 lb. can first be found as follows:--
grains grains yards
8 : 7000 ∷ 34
34
-------
8)238000
-------
29750 yards in 1 lb.;
and this divided by 840 will give the counts, thus:--
29750
----- = 35·41 counts.
840
From this we get the formula:--
7000 × yards weighed
-------------------- = counts.
840 × counts
This is a very useful formula, as when only a small piece of cloth is
available to be tested it is necessary to get as near as possible to
the counts from weighing sometimes only 10 or 15 yards, or any odd
length.
A calculation may occur in the following form:--
How many grains should 16 yards of 20’s cotton weigh?
There are 840 × 20 = 16,800 yards of 20’s in 1 lb., or 7000 grains.
Then if 16,800 yards weigh 7000 grains, how many grains will 16 yards
weigh?
yards yards grains
16800 : 16 ∷ 7000 : 6·6 grains.
This may be stated in a formula as follows:--
7000 × yards weighed
-------------------- = weight in grains.
840 × counts
=Staub’s Yarn Balance= is a small balance which is made to test
the counts of very small quantities of yarn. A template is given with
the balance, and the yarn is cut into lengths the size of the template,
about two inches. One end of the balance is slightly heavier than the
other, and the number of threads the size of the template which are
required to draw the balance indicate the counts of the yarn. If twenty
threads or about 40 inches balance the small weight, the count of the
yarn is 20’s, and so on.
The principle is the same as if a 1 lb. weight were put on one end of a
balance, in which case the number of hanks required to draw the weight
would indicate the counts, because if 20 hanks = 1 lb. the counts are
20’s, and if 21 hanks = 1 lb. the counts are 21’s. The balance may be
made to weigh any length, according to the weight on one end of the
balance.
The form in which it is usually made makes it specially suitable for
testing the counts in small patterns of a few inches.
The test is, of course, only approximate, as could only be expected
from weighing so short a length.
If the foregoing examples are thoroughly understood, the following will
not be found difficult.
If a warp has 2000 ends, and is 500 yards long, and weighs 60 lbs.,
what counts is it?
The ends multiplied by the length will give the total length of yarn in
the warp, and this divided by 840 will give the hanks. If the hanks are
divided by the weight, the result will be the counts. The result may be
obtained at once as follows:--
2000 × 500
---------- = 19·84 counts.
840 × 60
If a beam has 2200 ends, the counts being 40’s, and the weight 50 lbs.,
find the length.
By multiplying 40 by 840 the yards in 1 lb. are obtained, and
multiplying this by 50, the yards of yarn on the beam are arrived at.
If this is divided by the ends in the warp, the result will be the
length of warp thus:--
40 × 840 × 50
------------- = 763·6 yards.
2200
A simple method of mentally calculating the number of hanks in a piece
is as follows:--
A warp 84 yards long will contain just one-tenth as many hanks as ends.
Thus a warp of 2000 ends, 84 yards long, contains 200 hanks. This can
be proved as follows:--
2000 × 84
--------- = 200 hanks.
840
The number of hanks in a warp 84 yards long can thus be seen at once,
and it is a very simple matter to mentally calculate the difference for
any other length.
The hanks of weft can also be calculated mentally in a similar manner.
If the piece is 84 yards, the counts multiplied by the width and
divided by 10 will give the number of hanks required for 84 yards.
Thus, find the hanks of weft in a piece 34 inches wide, 84 yards long,
60 picks per inch.
60 × 34
------- = 204 hanks.
10
The calculation is really simpler than it looks in the above form, as
the dividing by 10 can be done by simply pointing off the last figure
in the product of the picks and width. The formula may be proved
correct by working out fully as follows:--
34 × 84 × 60
------------ = 204 hanks.
840
This system of mentally calculating the hanks is very useful, as it
serves as a check upon a full calculation.
=The Firmness of Cloth.=--The number of ends and picks per inch which
can advantageously be put into a fabric depends upon the number of
intersections per inch in the pattern or weave, and on the counts or
diameters of the yarns used. In a plain cloth woven with 32’s twist and
32’s weft, the number of threads per inch which could be put into the
cloth without undue compression would be a little more than one-half
the number which could be laid side by side touching each other. The
reason for this is that the warp and weft threads interlace with each
other every pick, and therefore, supposing that 156 threads of 32’s
occupy one inch when laid side by side, one-half of these threads
would have to be left out to allow of the intersection of the weft
between every end.
In a “two and two” twill the weft intersects once for every two ends,
or twice in the pattern; therefore there are four threads and two
intersections in the pattern. It is obvious, therefore, that to keep
the same firmness in the twill as in the plain cloth with the same
yarns, a larger number of threads per inch both in warp and weft will
be required.
To keep the same “firmness” the threads must be kept as close together
in one cloth as in the other, and as in a plain cloth one-half the
threads which occupy one inch are dropped out, so in a twill with
two intersections for four ends there must be one-third of the ends
occupying one inch left out. Thus with 32’s yarn, of which the diameter
is 1/156 of an inch, there will require to be about 102 threads per
inch in a “two and two” twill.
A perfectly balanced plain cloth may be defined as a cloth in which the
warp and weft yarns are equal in diameter, and the spaces between the
threads are equal to the diameter of the yarn.
If the diameters of yarns of various counts are known, it is an easy
matter to find the number of threads per inch which will produce the
desired firmness in any simple weave.
The diameters of yarns of cotton, woollen, worsted, and other threads
are given by the late Mr. T. R. Ashenhurst in an excellent little work
on “Textile Calculations and the Structure of Fabrics,” which has done
much to promote this branch of the art of weaving.
Mr. Ashenhurst estimates the diameter of a 32’s cotton yarn at the
1/148th part of an inch; but this is probably somewhat under the mark,
and in the following table I have taken 1/156th inch as the diameter of
32’s.
The variation in the thickness of any yarn, and the fact that they are
not strictly cylindrical, renders measurements of little avail, but
taken in conjunction with an examination of a range of woven cloths,
the approximate or practical diameter can be estimated.
TABLE OF DIAMETERS OF COTTON YARNS.
+---------+---------+
| Counts. |Diameter.|
+---------+---------+
| 1 | 27½ |
| 2 | 39 |
| 3 | 47½ |
| 4 | 55½ |
| 5 | 62 |
| 6 | 67½ |
| 7 | 73 |
| 8 | 78 |
| 9 | 83½ |
| 10 | 87½ |
| 11 | 91 |
| 12 | 95 |
| 13 | 99 |
| 14 | 103 |
| 15 | 106½ |
| 16 | 110 |
| 17 | 113 |
| 18 | 117 |
| 19 | 120 |
| 20 | 123½ |
| 21 | 126 |
| 22 | 129½ |
| 23 | 132 |
| 24 | 135 |
| 25 | 138 |
| 26 | 140½ |
| 28 | 145½ |
| 30 | 151 |
| 32 | 156 |
| 34 | 160½ |
| 36 | 165 |
| 38 | 169 |
| 40 | 174½ |
| 42 | 178 |
| 44 | 183 |
| 46 | 187 |
| 48 | 191 |
| 50 | 195 |
| 52 | 198½ |
| 54 | 202½ |
| 56 | 206 |
| 58 | 210 |
| 60 | 213 |
| 62 | 216½ |
| 64 | 220½ |
| 66 | 224 |
| 68 | 227 |
| 70 | 230½ |
| 72 | 233½ |
| 74 | 237 |
| 76 | 240½ |
| 78 | 243 |
| 80 | 246 |
| 82 | 249 |
| 84 | 252 |
| 86 | 256½ |
| 88 | 258½ |
| 90 | 261 |
| 92 | 264 |
| 94 | 267 |
| 96 | 270 |
| 98 | 272½ |
| 100 | 275½ |
| 105 | 282 |
| 110 | 289 |
| 115 | 295½ |
| 120 | 302 |
| 125 | 308 |
| 130 | 314 |
| 135 | 320 |
| 140 | 326 |
| 145 | 331½ |
| 150 | 337 |
| 160 | 349 |
| 170 | 359 |
| 180 | 369 |
| 190 | 380 |
| 200 | 390 |
+---------+---------+
The preceding is a table of the diameters of cotton yarns from 1’s
counts to 200’s. The number given as the diameter is the number of
threads which occupy the space of one inch when laid as close together
as possible without compression.
A perfectly balanced plain cloth will require one-half this number
of threads per inch, plus, perhaps, 5 per cent. for the threads being
forced somewhat out of the same plane in weaving.
=Relative Diameters of Yarns.=--The “counts” of yarns indicate
the number of hanks in 1 lb., and therefore a given length of 30’s is
twice as heavy as the same length of 60’s; but the diameter of the 30’s
will not be twice that of the 60’s, as the yarns are cylindrical, and
the diameters will vary as the square roots of the areas, which in this
case are as 1: 2.
If one thread is four times as heavy as another, and if it is of the
same _density_--which in these calculations is assumed, although it is
not strictly correct--the diameters of the two threads will be as 2: 1.
For example, looking at the tables, the diameter of a 60’s is seen to
be the 1/213 of an inch, whilst the diameter of a thread four times the
weight, viz. 15’s, is seen to be 1/106½ of an inch, or exactly twice
the diameter of the 60’s thread.
The diameter of one yarn being known, the diameter of any other may be
obtained by the following rule:--
RULE.--As the square root of one count is to the square root
of another count, so is the diameter of one to the diameter of the
other.
_Example._--If the diameter of a 16’s yarn is the 1/110th part of
an inch, find the diameter of a 36’s.
√(16) : √(36) ∷ 110
4 : 6 ∷ 110 : 165 _Ans._
In this form the calculation necessitates the extraction of two square
roots, and with most numbers would require the use of two fractions in
the calculation. By squaring all the three terms the calculation is
much simpler, as in the following example:--
_Example._--If the diameter of a 32’s is the 1/156 of an inch, what
is the diameter of a 50’s?
32’s : 50’s ∷ 156^2 : _x_^2
or 32 : 50 ∷ 24336 : _x_^2
50
-------
32)1216800(38025
96
---
256
256
------
80
64
----
160
160
and √38025 = 195 _Ans._
As the diameters of yarns vary as the square root of their counts, it
follows that the diameters will always bear a certain relation to the
yards in 1 lb. If this relation is once obtained, it becomes easy to
calculate the diameter of any yarn on this principle.
Taking the diameter of a 32’s yarn from the table, viz. 156, it will be
found that this is equal to the square root of the yards in 1 lb., less
5 per cent.
_Example._ 840
32
----
1680
2520
-----
26880 yds. in 1 lb. of 32’s.
√26880 = 164
8 = 5 per cent.
---
156 = diameter of 32’s.
The number of ends and picks per inch required to make plain cloths of
equal firmness from different counts may be at once seen from the table
of diameters, as one-half the number given as the diameter is required.
Thus if a plain cloth with 78 threads per inch of 32’s is taken as the
standard, and it is required to make a cloth of equal firmness, with
60’s yarns, the number of threads per inch required would be 106½. In
20’s yarns about 62 threads would be required. In 16’s yarns 55 threads
per inch, and so on.
In twills, or other regular weaves, the following rule will give the
number of threads per inch required of any count:--
RULE.--As the sum of the ends and intersections in the pattern
is to the ends, so is the diameter to the number of threads required.
_Example 1._--How many threads per inch are required to make a
perfectly balanced “2 and 1” twill cloth, with 24 yarns, warp and
weft?
There are 3 ends and 2 intersections in the pattern; therefore
3 ends + 2 intersections = 5;
and as 5 : 3 ends ∷ 135 diameter : _x_
3
---
5)405
----
81 threads per inch required.
_Example 2._--How many threads per inch are required to make a
perfectly balanced “3 up, 2 down, 2 up, 2 down twill” with 44’s
yarns?
In this pattern there are 9 ends and 4 intersections; therefore
as 9 + 4 : 9 ∷ 183 diameter of 44’s : _x_
or, as 13 : 9 ∷ 183
9
----
13)1647(126 threads per inch required
13
---
34
26
---
87
78
--
9
One of the most useful purposes to which a knowledge of this principle
can be put is in changing the weave of a fabric, to find the threads
per inch of a given count of yarn required to keep the same firmness as
in a sample cloth.
It must be remembered that the word “firmness” is here used as implying
that the space between the threads bears the same relation to the
diameters of the threads in both cases, or, if the given cloth is
perfect, the proposed one will also be perfect.
Suppose it is desired to make a “two and two” twill of the same
“firmness” as a plain cloth made with 103 threads per inch.
The yarns being the same, the number of threads per inch required will
be as the ends plus intersections in a given number of ends in both
patterns.
In the above question the given cloth is plain, with 103 threads per
inch, and the proposed cloth is a “two and two” twill. Taking the same
number of threads in each case, we get--
Ends + Intersections in Ends + Intersections
proposed twill cloth. in given plain cloth.
4 + 2 : 4 + 4 ∷ 103 : _x_
or 6 : 8 ∷ 103
8
----
6)824
----
Ends required in twill cloth = 137⅓
It must not be forgotten that it is necessary to take an equal number
of ends of each pattern in this class of calculation. In more complex
patterns it is often advisable to take the number of ends which is
the L.C.M. of the ends in the two patterns in order to get a
complete number of intersections in each case.
_Another Example._--If a “two and two” twill cloth is made with 137
threads per inch, and it is proposed to make a cloth with the same
counts of yarns in a “5 up, 2 down, 1 up, 2 down” twill, how many
threads per inch are required to keep the same firmness?
In 40 ends of the proposed cloth there are 16 intersections, and in
40 ends of the sample cloth there are 20 intersections.
Then as 40 + 16 : 40 + 20 ∷ 137
or 56 : 60 ∷ 137
60
----
56)8220(146.8 threads. _Ans._
56
262
224
----
380
336
----
440
If it is required to make a cloth with the same number of threads as a
sample cloth, and to change the pattern and keep the same firmness, it
is necessary to change the counts on the following principle:--
RULE.--As the sum of the ends and intersections in the sample
cloth is to the sum of the ends and intersections in the proposed
cloth, so is the square root of the counts in the sample to the square
root of the counts in the proposed cloth.
_Example._--If a plain cloth has been made with 36’s yarns, and
it is proposed to make a “two and two” twill with the same number
of threads per inch, find the counts required to keep the same
“firmness.”
Ends + Inters. Ends + Inters.
in sample cloth. in proposed cloth.
or 4 + 4 : 4 + 2 ∷ √36 : √x
8 : 6 ∷ 6 :
6
--
8)36
4½
And 4½^2 = 20·25 counts required.
This may be proved correct by referring to the table of diameters on
page 335, where it will be seen that a plain cloth with 82½ threads per
inch of 36’s is “perfect,” and a “two and two” twill with 82½ threads
of 20¼’s counts is equally perfect.
=To change the Counts=, the pattern and threads per inch remaining
the same.
If a sample cloth has 78 threads per inch of 32’s yarn, and it is
proposed to make a cloth of the same weave with 55 threads per inch,
what counts of yarn are required to keep the same “firmness”?
This is simple enough. The diameters of yarns vary as the square root
of their counts, and therefore as the threads in one cloth are to the
threads in another, so will the square root of the counts in one be to
the square root of the counts in the other.
Threads in Threads in proposed Counts in
sample. cloth. sample.
78 : 55 ∷ √32 : √x
or as 78^2 : 55^2 ∷ 32
6084 : 3025 ∷ 32
32
----
6050
9075
-----
6084 )96800(15·91, or 16’s nearly = counts
6084 required
-----
35960
On referring to the table of diameters (p. 335), it will be found that
a plain cloth with 78 threads of 32’s is “perfect,” and that a plain
cloth with 55 threads of 16’s is also perfect. Therefore the above
calculation is correct.
=To change the Threads per Inch=, the counts and pattern remaining
the same.
If a sample has 78 threads per inch of 32’s, and it is proposed to
weave a cloth of the same pattern, but with 60’s yarns, find the number
of threads per inch required to keep the same firmness.
This is simply a continuation of the previous statement.
If the two counts are known, the number of threads will vary as the
square roots of the counts; thus--
Counts in Counts in Threads in
sample. proposed cloth. sample.
√32 : √60 ∷ 78 : _x_
or as 32 : 60 ∷ 78^2 : _x_^2
6084
60
-------
32)365040
11407½
√11407 = 106.8 threads required.
The above may be proved correct by referring to the table of diameters.
A plain cloth with 78 threads per inch of 32’s is “perfect,” and so is
a plain cloth with 106½ threads per inch of 60’s.
The same principle must be employed if the warp and weft are of
different counts, or if the threads per inch are not equal in warp and
weft.
_Example._--A sample cloth is made with 78 ends per inch of 32’s
and 91 picks per inch of 44’s. How many picks will be required to
keep the same firmness, if the weft only is changed to 60’s?
Counts in Counts in
sample. proposed cloth.
√44 : √60 ∷ 91 : _x_
or as 44 : 60 ∷ 91^2 : _x_^2
8281
60
------
44)496860
------
11292 = _x_^2
------
and √11292 = 106½ ∴ picks per inch required = 106½
One advantage gained by a knowledge of the principle of cloth
“balance” is that the number of picks per inch which a given pattern
or weave will take can easily be obtained by calculation. This is of
great advantage to designers for Jacquard weaving, as it often occurs
that a design is made and the cards cut for a pattern which will not
admit of the required number of picks of the given counts being put in
the cloth, which a slight alteration in the ground weave would have
rendered possible.
=To alter the Weight.=--If the weight of a cloth is required to be
altered, and the same firmness kept, the threads per inch and counts
can be found on the same principle.
If a cloth is made heavier it must be done by using _coarser_ yarns and
_fewer_ threads; it cannot be done by using more threads, and preserve
the same “firmness” or “perfection.”
Suppose a sample piece of cloth weighing 10 lbs. is made with 93
threads of 45’s, and it is proposed to make a piece of the same length
and width, but weighing 15 lbs. To find the threads per inch and counts
of yarn to keep the same firmness.
The weights of two cloths will vary as the square roots of the counts
if they are of the same perfection.
Therefore--
Weight of Weight
proposed cloth. of sample.
As 15 lbs. : 10 lbs. ∷ √45 : √(_x_) counts
or 15^2 : 10^2 ∷ 45 to _x_
225 : 100 ∷ 45
100
----
225)4500(20’s counts required
450
----
0
To find the threads per inch required of the above counts--
Weight of Weight of
proposed cloth. sample.
15 : 10 ∷ 93
10
----
15)930(62 threads required.
90
----
30
30
----
Then to make a piece of the same perfection or firmness as the sample
piece, and to alter the weight from 10 lbs. to 15 lbs., the counts must
be changed from 45’s to 20’s, and the threads per inch from 93 to 62.
To prove this is correct take a piece 20 inches wide, 102 yards long,
93 threads per inch both in warp and weft of 45’s yarns.
The weight of this sample piece will be--
20 × 102 × 93
------------- = 5 lbs. of twist;
840 × 45
and as there is the same weight of weft, the total weight of the piece
will be 10 lbs.
Now calculate the weight of a piece of the same length and width with
62 threads per inch of 20’s yarns:--
20 × 102 × 62
------------- = 7½ lbs. of twist;
840 × 20
and with the same quantity of weft, the total weight of the piece will
be 15 lbs.
This proves the calculation to be correct so far as altering the weight
goes.
To see if both cloths are of the same firmness, the table of diameters
may be referred to. It will there be seen that a plain cloth with 93
threads per inch of 45’s yarn is “perfect,” and also that the altered
cloth with 62 threads of 20’s is equally perfect.
It thus proves the principle of the calculation to be correct.
A lighter cloth may be made, and the same firmness kept. The formula is
the same in both cases. If a cloth is made lighter it must be done by
using finer counts and more threads. It cannot be done by using fewer
threads, as the firmness could not be kept and the required weight
obtained.
In altering the weights of cloths some allowance would have to be
made for the difference in milling-up with different counts of yarns
and numbers of threads. If a cloth is made heavier, thicker yarns
would be used, and the warp length to give a certain length of piece
would be different in the sample to the altered cloth. But this is
a comparatively small matter, which can be adjusted with a slight
alteration in the basis of the structure.
INDEX
Antiseptics, 32
Automatic looms, 198
Backed cloths, with weft, 255;
with warp, 257
Barley-corn patterns, 235
Beaming, press, 47
---- tension, 47
Beating up the weft, 72, 85
----, character of motion in, 72, 73
----, distance moved by slay whilst the crank moves through given
angle in, 74
----, eccentricity of slay’s movement in, 72;
cause of, 74
----, effect of altering position of crank-shaft in, 83;
of reversing direction of crank in, 84
----, force of slay in, 78, 82
----, position of crank in, 72
Becks, size mixing, 30
Brake, 95
Calculation for two or more fold yarns, 308
---- of contraction for different weaves and counts, 326
---- of cost of a piece, 325
---- of counts of yarn from weighing given length, 329
Calculation of diameter of yarn, 336
Calculation of number of threads of given counts required to make a
firm cloth in any weave, 341
---- of quantity of warp and weft in a piece, 311-313
---- of reeds and setts, 310
---- of weaving wage, 324
---- of weight of a given length of any counts, 330
---- to make a cloth of equal firmness to given cloth when changing
weave, 338
---- to preserve firmness and alter weight, 343
---- to preserve firmness when changing threads per inch, 341
---- to preserve same firmness when changing counts, 341
Card-cutting machine, 190
---- repeater, 191
Casting out, 285
Checks produced by re-arranging twills, 241
Circular-box motion, 115
Clearer guide, 8
Clipped or sheared cloths, 254
Coiling motions. _See_ Taking-up
Combined twills, 226
Cop winding machine, 6
Cording plan for hand loom, 50
Cords, 245
Corkscrew twills, 257
Counts of cotton yarns, 307
Counts of two or more unequal threads twisted together, 308;
and weight of each required in given weight of resulting
thread, 309
Cover on cloth, 86, 87
Crapes, 248
Crimp cloth, 249
Damask or twilling Jacquards, 168-172
Design, transferring from sketch to point paper, 281
Detached figures, spots, arrangement of, 278-281
Development of pattern, 282-285
Diagonals, fancy, produced by combining unequal twills, 240
---- figured, 289
Diameters of cotton yarns, 335
Diapers, 233
Dice checks, 234
Direction of twist in yarns, effect of, 304
Dobbies, timing of movements in, 129
---- undermotions for, 130, 131
Dobby, the Blackburn, 127;
knife motion for, 127;
character of shed in, 129
----, the Keighley double-lift, 123;
method of pegging for, 126;
double jacks in, 126;
character of shed in, 125;
made positive, 129
Double cloths, 259
---- bound by passing back pick over face end, 261
---- bound by passing back end over face pick, 262
---- plain clothes, figuring, 263;
bound together, 266
---- shed Jacquard, 157
---- twill cloth figuring, 300
---- warp face, 257
Double weft face, 255
Double-beat slay, 135
Doup heald, 173
Draft, arranging on point paper, 227
---- the V, 230; patterns produced by, 230-233
Drawing-in, 3
Drills, 224
Drop-box motion, Diggle’s, 107
---- in pick-and-pick loom, 116;
connected to Jacquard, 120
---- Whitesmith’s, 112
---- Wright Shaw’s, 109
Drum winding machine, 13, 14
Edleston harness, 166
---- ---- designing for, 294
Extra warp, figuring with, 250;
reeding of, 252
---- ---- and extra weft combined, 255
---- weft, figuring with, 252
---- figure on mock leno ground, 254
Fancy effects produced by warp and weft pulling each other out of
straight line, 249
Fast reeds, 91
Figured design, 278
---- leno designing, 295
Firmness of cloth, 333
Gauze, plan of, 173
“Gloy,” 33
Grey warps, preparation of, 2
Hand-loom, 48
Hattersley weft-replenishing device, 214
Heck of warping mill, 22
Honeycomb designs, 242
Huck patterns, 250
Jacquard card cutting, 142, 190
---- damask or twilling, 168-172
---- damask, Tschorner and Wein, 172
---- double-shed, 157
---- for cross-border, 155
---- for leno weaving, 181
---- harness, bordered pattern, Norwich tie, 151;
London tie, 153
---- centre pattern or point tie, 154
---- Edleston’s, 166;
designing for,167, 294
---- for all-over pattern, 139
---- London tie, 150
---- Norwich tie, 144, 150
---- machine, origin of, 137
---- sizes of, 150
---- difference in character of shed between single and
double-lift, 137, 144-148
---- double-lift, single-cylinder, 144;
principle of, 145
---- double-lift, double-cylinder, 146;
advantages of, 144
---- single-lift, 138
---- open-shed, 158
---- pressure harness, 161-166
---- split harness, 160
Jeans, jeanettes, 220
Keighley dobby, 123
Kenyon’s undermotion for dobbies, 131
Lace and leno stripes, 269
Lags, pegging of, 126
Lappet loom, 193
---- wheel, construction of, 195
Lappets, 192
Leno checks, 268
---- crossovers, 175
Leno effects, 266
---- full cross, 181
---- Jacquards, designing for, 185
---- double-lift, 186
----, imitation of, 186
---- net or lace, 176
---- selvedge, 132
---- weaving in dobbies, 174-180;
use of slackener in, 174;
arrangement of staves and pegging plan, 175-178;
shaking motion for double-lift dobbies, 178;
arrangement of slackeners for two doups, 180
Letting-off, 106
Linen yarns, counts of, 307
List of prices for weaving, New Uniform, 314-322;
Chorley, 322
Loose reeds, 92
Marking mechanism in slashing frame, 35
Marseilles quilts, 298
Mildew, 32
Mitcheline, 299
Mock lenos, 243
Mono-coloured warps, preparation of, 3
Multi-coloured warps, preparation of, 5
Net lenos, 267
Northrop weft-replenishing device, 210
Oscillating tappets, 61
Padded cloths, 258
Patterns produced by combining alternate picks of twills, 240
---- by combining equal twills, 226;
unequal twills, 240
---- by drafting, 227
Patterns by fancy drafts, 238
---- by re-arrangement of simple twills, 236;
and of combined twills, 237
Pegging plan making, 228
Pick-and-pick loom, 116
Pick, force of, 69
Picking, over pick, 68, 69
---- under pick, 71
Pile fabrics, warp, 189
---- weft, 270-277
Piqués, 258
Pirn winding machine, 15
---- ---- ---- disc, 17
Plain cloth, 218
---- draft for weaving, 219
---- number of threads possible in, 218
---- ornamentation of, 218
Plushes, 189, 275
Point draft, 230
Point paper, selection of, for different proportions of warp and
weft, 290
---- use of, 219
Power-loom, tappet shedding motions in, 51-68
Preparatory processes, 1
Presser roller, expanding, 27
Pressure harness, designing for, 292
---- harnesses, 161-166
Primary movements in weaving, 48
---- timing of, 85-87
Protector, loose reed, 91
---- stop rod, 92
Reeds and setts, 310
Ribs and cords, 245
Roller top motion for plain cloth, 62;
3 staves, 64;
4 staves, 64;
5 staves, 65;
7 staves, 66
Sack weaving, 259
Satin draft, 229
---- weaves, 222
Satin, principle of construction of, 224
Scotch dressing, 42
Section blocks, expanding, 27
---- tappets, Woodcroft’s, 59, 60
Sectional warping, 23
Selvedge motion in sateen loom, 134, 135
Set figures, arrangement of, 278-281
Shading, 283
Shedding motions, power-loom, 51-68
Silk yarns, thrown or net, numbering of, 307
Sines and cosines, table of, 81
Singleton’s stop-motion, 19
Size mixing, 28
---- ---- for light sizing, 30
---- ---- for fine counts, 31
---- ---- for medium sizing, 31
---- ---- for heavy sizing, 32
Sizes of patterns woven in Jacquards, 285
Sizing, 28
---- ball, 43
---- materials, 28
----, slashing frame, 33;
slow motion in, 37
---- frame, slasher, marking motion in, 35, 36
---- ---- frictional winding motion in, 39
---- machines, hot air drying in, 38
---- ----, automatic supply of size to, 40
Slubbings, 8
Solid coloured borders in dhooties, 303
Split harness, designing for, 292
Splits, motion for, 132
---- Shorrock and Taylor’s motion for, 133
Spreading the warp, 85
Spun silk yarns, counts of, 307
Stitching-thread used to bind extra warp and extra weft, 252, 253
Stocks and bowls, 67
Stop motion, weft fork, 93
---- ----, in beam-warper, 19
---- rod, 92
Striped designs, 288;
calculation of reed for, 288
Tabby weave, 218
Taking-up motion, negative, 101;
screw and worm wheel, 103
---- positive, 95;
Pickles’, 99;
new system, 104
Tappets, calculation for lift of, 52
----, construction of, 53
----, effect of treadle-bowl on, 57
---- for plain cloth, 50, 51, 53
---- for twills, 56, 58
---- oscillating, 61
---- positive, 59
----, speed of, 87-91
---- Woodcroft’s, 59
Terry cloth, 187
---- loom, 187
Testing yarns, 329
Three-ply, four-ply cloths, 263
Toiletings, 297
Traverse motions, heart cam, 9, 10;
mangle wheel, 11 cloths, 258
Trial section, 25
Twaddell’s hydrometer, 30
Twills, 219
---- combined, 226
Twisting-in, 3
Twofold yarns, cotton, worsted, silk, 308
Undermotions, 130, 131
Undermotion, Kenyon’s, 131
V-creel, 18, 23
V-reed, 24
Velvet, common, 270
---- cords, 276
---- E1, 273
---- fast pile, 273
----, figured, 301
---- twill back, 274
Velvets, velveteens, 270, 277;
definition of, 272
Warp line, 85
Warping, beam, 18
Warping mill, 21
----, sectional, 23
Weaving wage calculations, 324
Weft, preparation of, 6
----, wet, 6
---- fork, 93
---- pile fabrics, 270
Weft-replenishing devices, automatic, 198-217
---- ----, patents for, 209
---- ----, Northrop, 210
---- ----, Hattersley, 214
Winding coloured yarn, 14
---- drum, 14
---- from cops to warpers’ bobbins, 6
---- from ring spools to warpers’ bobbins, 6
---- from throstle to warpers’ bobbins, 6
Woodcroft’s section tappets, 59, 60
Worsted yarns, 307
Wrapping yarn, 330
Yarn balance, Staub’s, 331
---- twist of, 305
Yorkshire dressing, 5, 47
THE END
PRINTED BY
WILLIAM CLOWES AND SONS, LIMITED
LONDON AND BECCLES
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