Messrs. Devoge & Co. can attach an arrangement to their machines so that they can be driven with a belt. The punch block is wrought by a lever driven by an eccentric, and is kept constantly rising and falling; the cutter fingers the pins so as to keep time with the punch block, and should he wish to stop, or should anything go wrong, he can stop the card at once by raising one treadle and pressing down the other, which throws the motion for shifting the index carriage out of gear, and the card stands stationary, and although the punch block continues to work it takes no effect when the punches are not locked by the keys. The machine works very smoothly, with very little noise, and with a little practice any boy or girl accustomed to card cutting can easily become acquainted with working it. The index of the piano machine is generally made for 51 rows of holes in the cards, 400, 500, and 600 machines being those generally employed: 51 rows of 8 = 408 needles; 51 rows of 10 = 510 needles; and 51 rows of 12 = 612 needles, which, with a few odd needles on the 25-row side, represent the number of needles in a 400, 500, and 600 machine. If larger machines with longer cords are required, the index of the cutting machine must be altered to suit them.
Card paper should be of such a quality as will not be easily affected by the atmosphere. When cards are for small machines, and are only required to work for a short time, an inferior paper will do for them, and save expense; but for large patterns which are intended to work for years it will come cheaper in the end to get a good quality of paper—in fact, the best that can be made. Specially prepared oil-saturated paper is made for the purpose of preventing the atmosphere taking too much effect on it. For hand looms, sometimes the cards are painted with red lead, and sometimes with shellac varnish, or shellac (best red) dissolved in methylated spirits.
Cards are made of different weights of paper; some prefer them thin, and others thick. A moderately thin, tough paper is the best. About 16 to 18 cards to 1 lb., for 400 cards, is a good medium weight.
After the cards are cut they have to be laced into a chain to revolve round the jacquard cylinder on the loom. The usual method of lacing is to have a frame with pegs or studs set in it at a distance apart to suit the size of the jacquard cylinder. The cards are spread on this frame as shown at A, [Fig. 94], and laced with a steel needle, thicker in the centre than at the ends; it is about 2-1/2 in. long, and has an eye in the centre, through which a piece of fine twine is tied in a loop, and the lacing tape can easily be drawn through this. The cards at A are numbered 1, 3, 5, but all the numbers would follow in rotation if the jacquard had only one cylinder; if a double-cylinder machine, half the cards would be laced forward, as at A, and the other half (the even numbers) backward, as at B. The odd numbers usually go to the back of the loom, and the even ones to the front.
Several kinds of cord and tape are used for lacing cards, but two plies of round cotton cord, well soaped or waxed, is usually the most satisfactory for wear.
When lacing cards, the lacings should be crossed over, each one passing from left to right of the other in turn, at each hole and between the cards. This is important, to keep the cards straight.
The cards should be tightly laced, as the lacing is almost certain to stretch a little; so that they are better for being rather tight for the cylinder at first, otherwise they are liable to become too slack after a little wear, and if such is the case they will not fall properly on the cylinder pegs. This and other causes—such as irregular expansion or contraction of the cards, badly cut cards, and a long draw on the cards—occasion considerable wear on the peg holes, and now eyelets are being tried in them to avoid the breaking-up of the holes; but it is probable that good paper and careful work will prove a more suitable remedy. The card should not be deeper than the face of the cylinder; better a trifle less, to allow for the lacing to pass between them, and then if laced as tightly as possible they will still be pliable and work freely. Cards are usually numbered with pen and ink, but the numbers may be stamped on with an indiarubber stamping machine similar to that used for paging books.
Fig. 94