Jacquard Weaving and Designing

by T. F. Bell

Fig. 12

Figs. 12a and 12b give detailed views of the hooks, etc., for drawing the harness: the letters in both refer to the same parts as are marked with similar letters in [Fig. 12]. The simples B are tied to loops on the hooks under the hole board C. In Fig. 12b it will be clearly seen how the needles in four rows act upon the hooks. The griffe consists of four round iron rods or wires set in the frame E, Fig. 12a, which can be drawn down by the treadle G, connected with the levers F by the cords 3 and 4. One of the levers has its fulcrum at one side and the other has it at the opposite side, and the points of the levers are tied to the griffe frame by the cords 1 and 2. The griffe, when sunk, is brought back to its place again by weights hanging on cords running over pulleys. It may be seen that the hooks hang in front of the rods or bars of the griffe; therefore, those hooks will be pushed on the griffe whose needles come against the solid portions of the cards, thus acting similarly to Bouchon’s machine. The hand bar for pressing the cards against the needles is shown at F. The needles can pass through the slot in it, and, when a card is pressed against the needles, the bar can be fastened with hooks for the purpose, so that the operator is free to depress the treadle. There are no springs on the needles, but a clap board comes behind them, which is pressed in by means of a cord passing over each end of it and fastened to a spiral spring. There are ten leaves of heddles in front of the harness. They are plain clasped heddles, and apparently act as five, the front five being raised by the top levers connected with the treadles, as shown in [Fig. 11], and the back five are held up by a set of levers at each side, with weights on the ends of them, similarly to those now used for hand-loom damasks, and tied to the treadles below, so that sinking a treadle would cause one of the back leaves to sink and one of the front ones to rise. Only the harness mechanism of Falcon’s loom is given in [Fig. 12], the front portion being similar to that of Bouchon, or to any hand loom.

Fig. 12a

Fig. 12b

In 1746 the accomplished mechanician, Vaucanson, altogether dispensed with the cumbrous tail cords and simple of the draw loom, and made the draw-boy machine completely self-acting by placing the hooks upright on the top of the loom, and hanging the harness from them. This loom may be seen in the Conservatoire des Arts, as well as a model of it on the same scale as those already mentioned—viz., one-third the size. The machine for drawing the harness is exactly like a small jacquard, with two rows of hooks and two rows of needles, as shown in [Fig. 13]. Instead of a square cylinder and cards, the pattern is punched on a band of paper, which passes over a round or true cylinder. This cylinder is fitted with a rack wheel, so that a tooth can be passed for each change of pattern, the cylinder moving out and turning one tooth, then pressing in against the cards again. The diameter of the cylinder is about twelve inches. The hooks are raised with a griffe, similar to that in a jacquard, which is fastened to a lever connected to a treadle below. This treadle, and four others for working the heddles, is wrought by tappets, made of wood, on a shaft running along the side of the loom and turned by a wince handle in front. Altogether, the loom is a nice mechanical contrivance, and a great step in advance of its predecessors.