The taking-up roller j is actuated through the series of wheels at the end of the loom by means of the oscillation of the slay-swords h, communicated through the pin 1, bracketed to the sword h, and called the "monkey-tail," which works in the slotted lever, oscillating on a fixed pin at the centre. The opposite end of this lever carries a catch, which actuates a ratchet-wheel placed inside the frame. As this wheel revolves, it is secured at every advance by a holding click. Its axle extends through an adjustable bracket, and carries the change-wheel, which gears into and gives motion to the taking-up wheel o, revolving on a fixed pin. This wheel has 120 teeth, and on its boss is cast a pinion of 14-20 teeth ; this gears into the beam-wheel p, which may have 75-90 teeth, according to the series adopted. The change-wheel n may have any number of teeth from 18-75, but when the cloth requires a very large one, the effect is obtained by giving the actuating-catch a double lift. The number of teeth in the change-wheel regulates the speed of the taking-up roller j, and thereby the number of picks—threads that cross the warp—per inch. The roller j drives the cloth roller k by friction, contact being preserved by the weighted levers g'. These complete the movements obtained directly from the top- or driving-shaft of the loom. The crank-shaft pinion-wheel, con taining usually 37 teeth, gears into the tappet-shaft wheel, with twice the number of teeth. The top-shaft therefore makes two revolutions while the tappet-shaft r makes one, the reason for which will be obvious. On the shaft r, immediately inside the frame, one at each side, are the picking Cones 8. As the shaft revolves, these strike the bowls t, carried on the bottom of the vertical picking-shafts u. The points of these cones are set on the shaft exactly opposite to each other, so that their strokes shall exactly alternate. The sharp impact of the cone s upon the bowl t, which is bolted in a slot of the shaft u, causes the latter to perform about rev. When this shaft is at rest, the picking-stick a, carried on the top of the shaft u, has its head u over the end of the shuttle box f ; and the partial revolution, caused by the action of the picking-cone, sharply sends it forward to the position shown in the drawing. A leather band descends from to, and is attached to the picker upon the spindle g, as shown in Fig. 570, the sudden drag upon which projects the shuttle to the opposite box. The tappets are two excentrios x on one boss, firmly secured on the middle of the shaft r. These, as the shaft revolves, alternately depress the two levers z, which work upon a pin fixed to the frame of the loom at the back, their opposite ends moving in the slots of the treadle grate y. When the beam a' contains a warp, this is drawn over the carrier-beam or roller b', and the healds are suspended from the heald-shaft, by means of cords attached to straps securely fixed upon the bosses of the shaft. Similar cords, on the bottom staves of the healds, receive into loops two long pieces of wood, called "lambs," from which descend rods connecting them with the treadles.
The operation may nnw be described. The loom having been supplied with a warp, which is carried upon the flanged beam a', the healds are attached as described above, the reed is secured in the space d, fitting into grooves in the slay and slay-cap e, the warp is drawn over the breast-beam d', the edges being previously secured upon fluted rollers, called temples, under the cover e', of which there is a corresponding one at the opposite side. From d', the warp passes obliquely down to and under the roller f', thence upon the taking-up roller j and to k, where the end is secured in a slot extending across its length.
When the other parts are adjusted, as may be required for the particular kind of cloth to be made, the shuttle is supplied with weft, and placed in the box, and the spring lever h' is pushed to the opposite extremity of the slot, where it is retained by a projection, and guides the strap from the loose to the fast pulley of the loom, causing all the parts simultaneously to commence working.
The slay is drawn back by the crank-shaft, the warp is opened by the tappets, and the shuttle is projected through the open shed, leaving a thread in its track. The slay advancing, carrying the reed, presses home the weft thread to a given position near the temple-rollers, when the warp closes, and, securing it in that position, opens in the opposite direction, the threads that were down before being now uppermost, when the loom swiftly returns the shuttle, which again leaves a thread in its track, to the box whence it first started, all the other parts of the loom repeating their action ; and so on consecutively.
The speed of a loom is described by the number of picks—the times it throws the shuttle across the warp—per minute. The modern plain loom as described, will pick 200-240 times a minute, according to its width, which is measured from the reed-space. The narrowest looms run quickest. A loom working at 220 picks a minute therefore weaves 2f in. of cloth, containing 20 picks a i in. in that time. This, however, is not a uniform pace ; allowances have to be made for stoppages for replenishing the shuttles with yarn, piecing broken warp threads, &c., &c.
All the movements of the loom are purely automatic, including self stopping, when the weft breaks. The stopping arrangement is an ingenious piece of mechanism, and has tended greatly to perfect the action of the loom, and render it more productive. It was patented in 1841 by William Kenworthy and James Bullough, both of Blackburn. The latter we believe was the inventor. In the slay, at the end of the reed-space, is fixed a small grate, shown in the drawing by three vertical lines. Opposite this grate, carried on a rod called the "fork-holder," is a three-pronged fork, with the prongs bent downwards about 1 in. from their base. The opposite end of the holder is inserted into the boss of a lever j', which moves on a stud at its extremity, seen near the spring lever V. A double lover, forming an obtuse angle, moves on a fixed pin at the angular point ; one portion which rises above the breast beam d' carries a head almost like a hammer, from which it has received that name. This head is recessed at the middle, so that it will receive a book on the handle of tho fork, which is bent at its extremity into that form. The seoond part of the lever ex tends from the pin obliquely to the tappet-shaft r, on which is fitted a bowl. As the shaft revolves, the bowl lifts the last-named lever, which causes the hammer of the second to be drawn backwards every time the slay c, carrying the reed d, pushes home a thread of weft. The fork-grate in the slay is thus brought to a position in which the prongs of the fork would pass between its bars, but are prevented from doing so by the presence of the thread of weft. The prongs in conseqnence are depressed, which raises the opposite extremity with the hook, thus allowing the hammer-lever to perform its traverse without producing any effect. But the moment the weft thread is broken, or disappears from exhaustion of the supply, the fork passes into the grate, its hook is caught by the hammer, and being drawn back, the lever j', into which the fork-holder is inserted, is carried with it, which pushes the spring lever kl out of the recess in the slot, when it moves to the position shown in the illustration, and shifts the driving strap from the fast to the loose pulley, thus stopping the loom.