Of machines for cropping or shearing woollen cloths, those of Lewis and
Davis have been very generally used.
_Fig._ 1219. is an end view, and _fig._ 1220. is a side view, of Lewis’s
machine, for shearing cloth from list to list. _Fig._ 1221. is an end
view of the carriage, with the rotatory cutter detached from the frame
of the machine, and upon a larger scale: _a_, is a cylinder of metal, on
which is fixed a triangular steel wire; this wire is previously bent
round the cylinder in the form of a screw, as represented at _a_, _a_,
in _fig._ 1219., and, being hardened, is intended to constitute one edge
of the shear or cutter.
[Illustration: 1219 1220 1221 1222 1223]
The axis of the cylindrical cutter _a_, turns in the frame _b_, which,
having proper adjustments, is mounted upon pivots _c_, in the standard
of the travelling carriage _d_, _d_; and _e_, is the fixed or ledger
blade, attached to a bar _f_, which constitutes the other edge of the
cutter; that is, the stationary blade, against which the edges of the
rotatory cutter act; _f_ and _g_, are flat springs, intended to keep the
cloth (shown by dots) up against the cutting edges. The form of these
flat springs _f_, _g_, is shown at _figs._ 1222. and 1223., as
consisting of plates of thin metal cut into narrow slips (_fig._ 1222.),
or perforated with long holes, (_fig._ 1223.) Their object is to support
the cloth, which is intended to pass between them, and operate as a
spring bed, bearing the surface of the cloth against the cutters, so
that its pile or nap may be cropped off or shorn as the carriage _d_ is
drawn along the top rails of the standard or frame of the machine _h_,
_h_, by means of cords.
The piece of cloth to be shorn, is wound upon the beam _k_, and its end
is then conducted through the machine, between the flat springs _f_ and
_g_ (as shown in _fig._ 1221.), to the other beam _l_, and is then made
fast; the sides or lists of the cloth being held and stretched by small
hooks, called habiting hooks. The cloth being thus placed in the
machine, and drawn tight, is held distended by means of ratchets on the
ends of the beams _k_ and _l_, and palls. In commencing the operation of
shearing, the carriage _d_, must be brought back, as in _fig._ 1221., so
that the cutters shall be close to the list; the frame of the cutters is
raised up on its pivots as it recedes, in order to keep the cloth from
injury, but is lowered again previously to being put in action. A band
or winch is applied to the rigger or pulley _m_, which, by means of an
endless cord passed round the pulley _n_, at the reverse end of the axle
of _m_, and round the other pulleys _o_ and _p_, and the small pulley
_q_, on the axle of the cylindrical cutter, gives the cylindrical cutter
a very rapid rotatory motion; at the same time a worm, or endless screw,
on the axle of _m_ and _n_, taking into the teeth of the large wheel
_r_, causes that wheel to revolve, and a small drum _s_, upon its axle,
to coil up the cord, by which the carriage _d_, with the cutters _a_ and
_e_, and the spring bed _f_ and _g_, are slowly, but progressively, made
to advance, and to carry the cutters over the face of the cloth, from
list to list; the rapid rotation of the cutting cylinder _a_, producing
the operation of cropping or shearing the pile.
Upon the cutting cylinder, between the spiral blades, it is proposed to
place stripes of plush, to answer the purpose of brushes, to raise the
nap or pile as the cylinder goes around, and thereby assist in bringing
the points of the wool up to the cutters.
The same contrivance is adapted to a machine for shearing the cloth
lengthwise.
[Illustration: 1224 1225]
_Fig._ 1224. is a geometrical elevation of one side of Mr. Davis’s
machine. _Fig._ 1225. a plan or horizontal representation of the same,
as seen in the top; and _fig._ 1226. a section taken vertically across
the machine near the middle, for the purpose of displaying the working
parts more perfectly than in the two preceding figures. These three
figures represent a complete machine in working condition, the cutters
being worked by a rotatory motion, and the cloth so placed in the
carriage as to be cut from list to list. _a_, _a_, _a_, is a frame or
standard, of wood or iron, firmly bolted together by cross braces at the
ends and in the middle. In the upper side-rails of the standard, there
is a series of axles carrying anti-friction wheels _b_, _b_, _b_, upon
which the side-rails _c_, _c_, of the carriage or frame that bears the
cloth runs, when it is passing under the cutters in the operation of
shearing. The side-rails _c_, _c_, are straight bars of iron, formed
with edges _v_, on their under sides, which run smoothly in the grooves
of the rollers _b_, _b_, _b_. These side-rails are firmly held together
by the end stretchers _d_, _d_. The sliding frame has attached to it the
two lower rollers _e_, _e_, upon which the cloth intended to be shorn is
wound; the two upper lateral rollers _f_, _f_, over which the cloth is
conducted and held up; and the two end rollers _g_, _g_, by which the
habiting rails _h_, _h_, are drawn tight.
In preparing to shear a piece of cloth, the whole length of the piece
is, in the first place, tightly rolled upon one of the lower rollers
_e_, which must be something longer than the breadth of the cloth from
list to list. The end of the piece is then raised, and passed over the
top of the lateral rollers _f_, _f_, whence it is carried down to the
other roller _e_, and its end or farral is made fast to that roller. The
hooks of the habiting rails _h_, _h_, are then put into the lists, and
the two lower rollers _e_, _e_, with the two end rollers _g_, _g_, are
then turned, for the purpose of drawing up the cloth, and straining it
tight, which tension is preserved by ratchet wheels attached to the ends
of the respective rollers, with palls dropping into their teeth. The
frame carrying the cloth, is now slidden along upon the top standard
rails by hand, so that the list shall be brought nearly up to the
cutter _i_, _i_, ready to commence the shearing operation; the bed is
then raised, which brings the cloth up against the edges of the shears.
[Illustration: 1226]
The construction of the bed will be seen by reference to the cross
section _fig._ 1226. It consists of an iron or other metal roller _k_,
_k_, turned to a truly cylindrical figure, and covered with cloth or
leather, to afford a small degree of elasticity. This roller is mounted
upon pivots in a frame _l_, _l_, and is supported by a smaller roller
_m_, similarly mounted, which roller _m_, is intended merely to prevent
any bending or depression of the central part of the upper roller or bed
_k_, _k_, so that the cloth may be kept in close contact with the whole
length of the cutting blades.
In order to allow the bed _k_ to rise and fall, for the purpose of
bringing the cloth up to the cutters to be shorn, or lowering it away
from them after the operation, the frame _l_, _l_, is made to slide up
and down in the grooved standard _n_, _n_, the movable part enclosed
within the standard being shown by dots. This standard _n_, is situated
about the middle of the machine, crossing it immediately under the
cutters, and is made fast to the frame _a_, by bolts and screws. There
is a lever _o_, attached to the lower cross-rail of the standard, which
turns upon a fulcrum-pin, the extremity of the shorter arm of which
lever acts under the centre of the sliding-frame, so that by the lever
_o_, the sliding-frame, with the bed, may be raised or lowered, and when
so raised, be held up by a spring catch _j_.
[Illustration: 1227]
It being now explained by what means the bed which supports the cloth is
constructed, and brought up, so as to keep the cloth in close contact
with the cutters, while the operation of shearing is going on; it is
necessary, in the next place, to describe the construction of the
cutters, and their mode of working; for which purpose, in addition to
what is shown in the first three figures, the cutters are also
represented detached, and upon a larger scale, in _fig._ 1227.
In this figure is exhibited a portion of the cutters in the same
situation as in _fig._ 1221.; and alongside of it is a section of the
same, taken through it at right angles to the former; _p_, is a metallic
bar or rib, somewhat of a wedge form, which is fastened to the top part
of the standard _a_, _a_, seen best in _fig._ 1220. To this bar a
straight blade of steel _g_, is attached by screws, the edge of which
stands forward even with the centre or axis of the cylindrical cutter
_i_, and forms the ledger blade, or lower fixed edge of the shears. This
blade remains stationary, and is in close contact with the pile or nap
of the cloth, when the bed _k_, is raised, in the manner above
described.
The cutter or upper blade of the shears, is formed by inserting two or
more strips of plate steel _r_, _r_, in twisted directions, into grooves
in the metallic cylinder _i_, _i_, the edges of which blades _r_, as the
cylinder _i_ revolves, traverse along the edge of the fixed or ledger
blade _g_, and by their obliquity produce a cutting action like shears;
the edges of the two blades taking hold of the pile or raised nap, as
the cloth passes under it, shaves off the superfluous ends of the wool,
and leaves the face smooth.
Rotatory motion is given to the cutting cylinder _i_, by means of a band
leading from the wheel _s_, which passes round the pulley fixed on the
end of the cylinder _i_, the wheel _s_ being driven by a band leading
from the rotatory part of a steam-engine, or any other first mover, and
passed round the rigger _t_, fixed on the axle _s_. Tension is given to
this band by a tightening pulley _u_, mounted on an adjustable
sliding-piece _v_, which is secured to the standard by a screw; and this
rigger is thrown in and out of geer by a clutch-box and lever, which
sets the machine going, or stops it.
In order to give a drawing stroke to the cutter, which will cause the
piece of cloth to be shorn off with better effect, the upper cutter has
a slight lateral action, produced by the axle of the cutting cylinder
being made sufficiently long to allow of its sliding laterally about an
inch in its bearings; which sliding is effected by a cam _w_, fixed at
one end. This cam is formed by an oblique groove, cut round the axle,
(see _w_, _fig._ 1227.) and a tooth _x_, fixed to the frame or standard
which works in it, as the cylinder revolves. By means of this tooth, the
cylinder is made to slide laterally, a distance equal to the obliquity
of the groove _w_, which produces the drawing stroke of the upper shear.
In order that the rotation of the shearing cylinder may not be
obstructed by friction, the tooth _x_, is made of two pieces, set a
little apart, so as to afford a small degree of elasticity.
The manner of passing the cloth progressively under the cutters is as
follows:--On the axle of the wheel _s_, and immediately behind that
wheel, there is a small rigger, from which a band passes to a wheel _y_,
mounted in an axle turning in bearings on the lower side-rail of the
standard _a_. At the reverse extremity of this axle, there is another
small rigger 1, from which a band passes to a wheel 2, fixed on the axle
3, which crosses near the middle of the machine, seen in _fig._ 1226.
Upon this axle there is a sliding pulley 4, round which a cord is passed
several times, whose extremities are made fast to the ends of the
sliding carriage _d_; when, therefore, this pulley is locked to the
axle, which is done by a clutch box, the previously described movements
of the machine cause the pulley 4 to revolve, and by means of the rope
passed round it, to draw the frame, with the cloth, slowly and
progressively along under the cutters.
It remains only to point out the contrivance whereby the machinery
throws itself out of geer, and stops its operations, when the edge of
the cloth or list arrives at the cutters.
At the end of one of the habiting rails _h_, there is a stop affixed by
a nut and screw 5, which, by the advance of the carriage, is brought up
and made to press against a lever 6; when an arm from this lever 6,
acting under the catch 7, raises the catch up, and allows the hand-lever
8, which is pressed upon by a strong spring, to throw the clutch-box 10,
out of geer with the wheel 8; whereby the evolution of the machine
instantly ceases. The lower part of the lever 6, being connected by a
joint to the top of the lever _j_, the receding of the lever 6, draws
back the lower catch _j_, and allows the sliding frame _l_, _l_, within
the bed _k_, to descend. By now turning the lower rollers _e_, _e_,
another portion of the cloth is brought up to be shorn; and when it is
properly habited and strained, by the means above described, the
carriage is slidden back, and, the parts being all thrown into geer, the
operation goes on as before.
Mr. Hirst’s improvements in manufacturing woollen cloths, for which a
patent was obtained in February, 1830, apply to that part of the process
where a permanent lustre is given usually by what is called
roll-boiling; that is, stewing the cloth, when tightly wound upon a
roller, in a vessel of hot water or steam. As there are many
disadvantages attendant upon the operation of roll-boiling, such as
injuring the cloths, by overheating them, which weakens the fibre of the
wool, and also changes some colours, he substituted, in place of it, a
particular mode of acting upon the cloths, by occasional or intermitted
immersion in hot water, and also in cold water, which operations may be
performed either with or without pressure upon the cloth, as
circumstances may require.
[Illustration: 1228 1229 1230]
The apparatus which he proposes to employ for carrying on his improved
process, is shown in the accompanying drawing. _Fig._ 1228. is a front
view of the apparatus, complete, and in working order; _fig._ 1229. is a
section, taken transversely through the middle of the machine, in the
direction of _fig._ 1230.; and _fig._ 1230. is an end view of the same;
_a_, _a_, _a_, is a vessel or tank, made of iron or wood, or any other
suitable material: sloping at the back and front, and perpendicular at
the ends. This tank must be sufficiently large to admit of half the
diameter of the cylinder or drum _b_, _b_, _b_, being immersed into it,
which drum is about four feet diameter, and about six feet long, or
something more than the width of the piece of cloth intended to be
operated upon. This cylinder or drum _b_, _b_, is constructed by
combining segments of wood cut radially on their edges, secured by
screw-bolts to the rims of the iron wheels, having arms, with an axle
passing through the middle.
The cylinder or drum being thus formed, rendered smooth on its
periphery, and mounted upon its axle in the tank, the piece of cloth is
wound upon it as tightly as possible, which is done by placing it in a
heap upon a stool, as at _c_, _fig._ 1229., passing its end over and
between the tension-rollers _d_, _e_, and then securing it to the drum,
the cloth is progressively drawn from the heap, between the
tension-rollers, which are confined by a pall and ratchet, on to the
periphery of the drum, by causing the drum to revolve upon its axis,
until the whole piece of cloth is tightly wound upon the drum; it is
then bound round with canvas or other wrappers, to keep it secure.
If the tank has not been previously charged with clean and pure water,
it is now filled to the brim, as shown at _fig._ 1229., and opening the
stopcock of the pipe _f_, which leads from a boiler, the steam is
allowed to blow through the pipe, and discharge itself at the lower end,
by which means the temperature of the water is raised in the tank to
about 170° Fahr. Before the temperature of the water has got up, the
drum is set in slow rotatory motion, in order that the cloth may be
uniformly heated throughout; the drum making about one rotation per
minute. The cloth, by immersion in the hot water, and passing through
the cold air, in succession, for the space of about eight hours, gets a
smooth soft face, the texture not being rendered harsh, or otherwise
injured, as is frequently the case by roll-boiling.
Uniform rotatory motion to the drum is shown in _fig._ 1228., in which
_g_ is an endless screw or worm, placed horizontally, and driven by a
steam-engine or any other first mover employed in the factory. This
endless screw takes into the teeth of, and drives, the vertical wheel
_h_, upon the axle of which the coupling-box _i_, _i_, is fixed, and,
consequently, continually revolves with it. At the end of the shaft of
the drum, a pair of sliding clutches _k_, _k_, are mounted, which, when
projected forward, as shown by dots in _fig._ 1228., produce the
coupling or locking of the drum-shaft to the driving wheel, by which the
drum is put in motion; but on withdrawing the clutches _k_, _k_, from
the coupling-box _i_, _i_, as in the figure, the drum immediately stands
still.
After operating upon the cloth in the way described, by passing it
through hot water for the space of time required, the hot water is to be
withdrawn by a cock at the bottom, or otherwise, and cold water
introduced into the tank in its stead; in which cold water the cloth is
to be continued turning, in the manner above described, for the space of
twenty-four hours, which will perfectly fix the lustre that the face of
the cloth has acquired by its immersion in the hot water, and leave the
pile or nap, to the touch, in a soft silky state.
In the cold-water operation he sometimes employs a heavy pressing roller
_l_, which, being mounted in slots in the frame or standard, revolve
with the large drum, rolling over the back of the cloth as it goes
round. This roller may be made to act upon the cloth with any required
pressure, by depressing the screws _m_, _m_, or by the employment of
weighted levers, if that should be thought necessary.
_Pressing_ is the last finish of cloth to give it a smooth level
surface. The piece is folded backwards and forwards in yard lengths, so
as to form a thick package on the board of a screw or hydraulic press.
Between every fold sheets of glazed paper are placed to prevent the
contiguous surfaces of cloth from coming into contact; and at the end of
every twenty yards, three hot iron plates are inserted between the
folds, the plates being laid side by side, so as to occupy the whole
surface of the folds. Thin sheets of iron not heated are also inserted
above and below the hot plates to moderate the heat. When the packs of
cloth are properly folded, and piled in sufficient number in the press,
they are subjected to a severe compression, and left under its influence
till the plates get cold. The cloth is now taken out and folded again,
so that the creases of the former folds may come opposite to the flat
faces of the paper, and be removed by a second pressure. In finishing
superfine cloths, however, a very slight pressure is given with iron
plates but moderately warmed. The satiny lustre and smoothness given by
strong compression with much heat is objectionable, as it renders the
surface apt to become spotted and disfigured by rain.
WOOTZ, is the Indian name of steel.
WORT, is the fermentable infusion of malt or grains. See BEER.
WOULFE’S APPARATUS, is a series of vessels, connected by tubes, for the
purpose of condensing gaseous products in water. See ACETIC ACID, _fig._
1.; also MURIATIC ACID.