Taking a 400 hook machine, the commonest size used for cotton weaving, we find a row of 8 needles or lances E of thin wire, arranged horizontally; at the left hand we see each of these attached to a spring in the spring box A, the other end projecting about 3/8-inch through a needle board B. Each lance regulates a vertical wire hooked top and bottom, and shown with each upper hook standing over its respective griffe or knife C. These griffes, eight in number, are lifted simultaneously through being connected together at the ends. The lower end of the hook rests on a wire grid J, slotted so as to allow the lower end of the hooks—to which are attached the neck cords F—to pass through. A bottom board below the bend is used for those machines which have no wire grid. To these neck cords is attached the harness—i.e., linen threads or leashes, some seven feet in length, carrying a brass mail-eye H, through which the end of warp is drawn. Just above the mail-eye the harness passes through a cumber board C, for the purpose of keeping in proper order and regulating the number of leashes per inch. At the bottom of each leash is fixed a metal weight, called a lingo, intended to pull the leash down after having been raised to form the shed.
The method of raising the ends is as follows:—A square cylinder is placed at D, and makes a quarter of a revolution at each pick. This cylinder carries a set of cards (N1, N2, N3), sheets of cardboard perforated in places. Supposing a 400 (408) machine is referred to, each card has space for 408 perforations, the holes corresponding in position with the ends of the 408 needles projecting through the needle board. A hole indicates a lift.
The Cards.
The cards are only perforated by groups of holes distributed incidentally, and where no perforation is made the needles at that point are pushed back 3/8-inch by the cylinder. This is sufficient to remove the tops of the corresponding hooks attached to these needles from their position over the griffe; thus, when this knife or griffe is lifted it does not actuate these hooks, but only those which were not pushed back by the cylinder and card. Suppose, for instance, one hook out of four had to be lifted, then 102 perforations would be made in the card, and 306 hooks would thus be pressed back, whilst 102 only would be lifted. The holes in these cards can be cut in any order, and as one card acts for one pick only, it is easy to realise the extent of the patterns which may be made; a cloth, for example, requiring 200 picks to the round, all of which may be different in the order or number of ends lifted, would require a set of 200 cards.
In what is called a 400 machine, 408 hooks are used, the needles being arranged in 51 rows of 8 each; one row only is shown in [Fig. 62], thus the others are arranged at the back of the one shown and in line with it.
A 100 machine is in rows of 4.
A 200 (204) machine is in rows of 4 or 8.
A 300 (304) machine is in rows of 6, 8 or 12.
A 600 (612) machine is in rows of 12.
An 800 (816) machine is in rows of 8 (usually 2/400’s).
A 1200 (1224) machine is in rows of 12 (usually 2/600’s).