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).
The knives are placed on the slant so that their edge more readily catches the hook in lifting, while their under side presses the hooks out of the way when dropping.
To place 408 hooks in one row is of course out of the question, and for compactness they are placed in 51 upright rows of 8’s; this advantage is more apparent in 1800 hook machines—the largest made.
The machine is fixed to a gantree above the loom (Frontispiece), and in a single-action jacquard motion, such as has just been described, the knife is raised by a lever over the machine, worked by an upright rod driven by an eccentric or crank on the crank-shaft, so as to give one lift for every pick. The cylinder is suspended to a batten swinging from the top, and also worked by connection with the crank-shaft. The movement of the cylinder is to and fro; as it is moving from the needle board one corner is caught by a latch and the cylinder partially revolves, bringing another card to face the needles, against which it is then pressed. The batten type is preferable to the sliding cylinder, which is only used in sheds where the building renders the sliding cylinder more applicable. The frame work of the batten is more solid and strong.