Jacquard Weaving and Designing

by T. F. Bell

Fig. 123

Fig. 124

If the machine was fixed on the loom for a Norwich tie, or with the cards to hang over the back, then the connections from the levers might all be at the centres of the lifters and the bars D would only be required to steady them. The levers for raising the lifters are shown at F, with their fulcrum at I. G is a spring, one of which is attached to each lever to keep it down, as the tappet has not a positive rising and sinking motion, only raising the levers and allowing their own weight and the draw of the springs to recover them. One of the connecting rods from the lever to the tappet is shown at I. [Fig. 124] gives the principle of this tappet. A is the lever or treadle with its fulcrum at A; the connecting rod B connects the point of it to one of the top levers F ([Fig. 123]), and C is a bowl at the other end of it which travels on the tappet plate D. The tappet is made up of 17 plates struck to suit; 16 of these are for working the lifters and 1 for the cylinder; it sits at the side of the loom like a Woodcroft tappet. For an 8-end satin twill 16 levers are required, 8 for the bottom set of lifters and 8 for the top set. Fig. 123a shows two lifters B¹ and C¹ with hooks and needles. A hook and a needle on a larger scale are shown in [Fig. 125]. The hooks are flat pieces of iron cut to the shape shown, with small projecting pieces, as a, riveted to them, by which they can rest on the bottom lifting knives, as at C¹ (Fig. 123a), so that when any of these knives are lifted a row of hooks will be raised by them. As before explained in reference to the Bessbrook machine, it is necessary when the pattern card presses on the needles for all the knives except one to act, and also for one of the bottom lifters to rise to form the texture of the cloth; the same must be in this machine, and can easily be regulated by the tappet, which should hold up the warp required for the pattern and work the ground texture as well. This is done in the following manner: Suppose there are 16 lifters, 8 top and 8 bottom ones. When the card presses on the needles, 7 of the top and 1 of the bottom lifters should be raised by the tappet, and the top lifter, which is left down, should be raised so far as to catch the heads of those hooks in the row belonging to it that are not pushed back by the card. For the next shot this lifter is raised and another one let down, but it is not let down far enough for the hooks to get off it, stopping at the same height that the first one was raised to, which is easily regulated by the tappet. If there are 3 shots to the card, another similar change takes place; then for the fourth shot all the lifters are dropped, the cylinder presses in, and all but one of the top lifters and one of the lower ones are again raised, and the twill proceeded with as before. It will thus be seen that the shedding for the twill acts as in a double-acting jacquard, but the lift at the change of card is similar to that of a single-acting jacquard. Of course the tappet must be struck to change the lifters according to the twill required on the cloth. In the Bessbrook machine there could be 16, 24, or 32 rows of hooks to 8 rows of needles by having 2, 3, or 4 hooks to each needle, or the number of hooks to each needle might vary and any number of needles might be used. There must be a knife for each row of hooks, but all the knives belong to the one griffe. In the Karl Wein machine there must be 2 lifters for each row of hooks, and 16 of them are enough to have for convenience. In the machine exhibited, 16 hooks, or 2 rows of 8, were attached to 6 needles, 4 needles having 3 hooks to each and 2 needles 2 hooks to each, as shown at B ([Fig. 125]), the thick vertical lines representing 1 row of hooks, and the thin lines the next row. There were 6 rows of needles in the needle board, and the point of each needle was cranked as shown at C; each row of holes for the needles in the needle board, or face-plate, stood between 2 rows of hooks: the first 3 needles were connected with 1 row of hooks and the second 3 with the next row, the cranks of the first and second set of needles being turned in the opposite direction so as to enable them to fall in with the rows of hooks. Of course there might as well have been 8 rows of needles with 2 hooks to each, or 4 needles to each row of hooks.

Fig. 125

If necessary to use more than one machine, some arrangement would require to be made for lifting them. It might be done by using a double set of levers with connecting rods similar to those used for twilling looms.

The twilling of the ground might be wrought by a griffe and hooks as in the Bessbrook machine, thus doing away with seven treadles and seven tappet plates, but this would make the twilling a single-acting shedding motion.