One of the most desirable arrangements is shown in the figure: A, A are the two hooks; B, B are two small springs by which the two levers, C, C are attached to the hooks with cords; D is the frame for holding the levers, and is fastened to the top rail of the loom, under the jacquard, or in any convenient place. It will be observed that the front bar of the frame passes above the levers, so that it will prevent them rising above the half-draw of the hooks, in which position they are shown. E, E are two cords connected with a jack or tumbler, F, on the end of a bell-crank lever, G H L, having its fulcrum at H, which may be on the same stud as the weft fork lever, or in any convenient place.
The weight of F and G keeps the cords in tension, and the point L of the lever is set behind the lever on the loom which carries the weft fork, at such a distance from it that when one of the cords E is drawn it does not act on it; but when both hooks are raised, drawing up the two cords, the point L of the lever presses against the weft fork lever, pushing off the belt handle and stopping the loom.
The lever G H L may act directly on the belt handle, if desired; in this case it would be fixed outside the loom framing. The cards are cut on the same principle as for the last motion, but the same holes will do in both sets of cards, as the two needles are acted upon by the same number of holes in both back and front sets; that is, for two hooks coming beside each other.
The following order of cutting will answer:--
1 3 5 7 2 4 6 8 --- --- --- --- --- --- --- --- O O · · · · O O
Cut the large dots on the number of cards given, and of course they must be cut to suit the needles connected with the hooks used.
The above gives a continuous working of the motion, but it would be sufficient for it to work at intervals having 8 or 10 shots between them, as--
1 3 5 7 9 11 13 15 17 19 2 4 6 8 10 12 14 16 18 20 --------------------------------------------------------------------- O O · · · · · · · · · · O O · · · O O ·
This will not allow the loom to run for more than 20 shots after the cards get out of order.
Some other motions are in use, but these are simpler.
Before describing twilling machines or any special make of jacquards, it may perhaps be better to explain the mounting of ordinary machines, according to the usual methods adopted in some of the leading districts.