Jacquard Weaving and Designing

by T. F. Bell

HARNESS TWINE

The size of harness twine used varies greatly; some prefer a fine, and others a heavy, twine. For the sleepers and hangers, 4 ply of 22’s or 5 ply of 30’s linen yarn is a very good medium size, and 4 ply of 14’s or 5 ply of 18’s or 20’s is a very good size for the neck or body of the harness.

Sometimes, for heavy damask, cable cord is used for the body of the harness, and is a good wearing cord; it is especially suited when the neck cords are fastened to the sleepers below the cumber board. This cord is made of good flax yarn; 5 ply of 30’s are twisted together, and three of these cords are then twisted together, or 3 ply of 18’s afterwards made 3 ply. A better size for medium work is 5 ply of 35’s made 3 ply, or 3 ply of 20’s or 22’s made 3 ply. Heavy harness twine requires to have heavier lingoes, particularly on those parts of the harness that are much slanted, in order to have the same effect on them that they would have on light twine. Some go to the opposite extreme, and use very light twine, such as 4 ply of 30’s, which is only fit for very light work in a narrow loom, where there will be but little friction on the cumber board, and where no heck is required. Lighter twine will suit better for a hand loom than for a power loom; 4 ply of 30’s for the harness of a hand loom, with lingoes of 50 or 60 to the lb., would do very well for a light cotton warp.

SETTING THE JACQUARD

The proper position for the jacquard, when only one is required on the loom, is so that the centre hook in it will be above the centre hole of the cumber board. This can easily be found by tying a plumb line to the centre hook of the machine and moving it, if necessary, till the plummet rests over the centre of the cumber board. In case the cumber board is not fixed in position, that of the jacquard may be found by having the plumb line to pass about half an inch more than the half breadth of the harness at the cumber board behind the top rail of the lay when it is full back, and it should also be at equal distances from each side of the loom. When more than one jacquard is required, they should be arranged evenly over the cumber board, and as close together as possible.

Sometimes the jacquard may be set farther forward or back to suit circumstances, such as getting card space, the only disadvantage being that there will be more slanting of the cords at one side than the other, and more friction on them in the cumber board, also more drag on the hooks on this side if no heck is used, and if a heck is used the cords will have to bear the friction on it. The more direct the cords of the harness can be, the better, and the above setting of the jacquard should be adhered to when possible, but it is not absolutely necessary for working to have it so.

It is always well to have the jacquards so arranged that they can be raised or lowered a little by having them resting on bars, which can be raised or lowered with screws. This is in case the harness is levelled higher or lower than might afterwards be desired; but if the breast beam of the loom, with the lay and back rail, can be raised or lowered, it will suit the same purpose, and it is better not to move the machine once it is fixed and the harness tied up.

The height the jacquard is to be above the loom must in many cases be regulated by circumstances; for instance, the height of the roof, or if the beams of the roof interfere with the working of it; sometimes the machines rest on the framing of the loom—that is, if the loom is made for a jacquard—and sometimes plain looms are used, and the machines rest on beams supported from columns, or from the roof of the house. This latter is the best plan, as it keeps the jacquard free from the shaking of the loom, which is particularly useful in the case of looms fitted with the knock-off motion. A good height for a jacquard, independent of circumstances, is to have 8 ft. or 8 ft. 6 in. from the mails to the bottoms of the hooks for a 10/4 loom—that is, one with about 100 in. reed space; 7 ft. to 7 ft. 6 in. for an 8/4 (82 in. reed space), and 5 ft. 6 in. to 6 ft. for a 4/4 (40 in. or 42 in. reed space), are very good heights. 5 ft. 6 in. is about right for a narrow harness, say 20 in. to 27 in. wide; 6 ft. would do for 80 in. wide, and 7 ft. or 7 ft. 6 in. for 90 in. wide, if necessary.

HECKS OR GUIDE REEDS

A heck is a frame of hard wood with wires across it, a wire for each row of hooks in the machine, from back to front. It should be made to suit the machine, so that when the harness passes from the hooks between the wires, it will go vertically down, and have no slant in it. In narrow hecks, there is usually one cross-stay to support the wires, but for broader machines there should be at least two. The wire should be iron, as brass soon cuts with the friction of the cords, and then in turn cuts the cords. For a single-acting machine the wires should be loose, so that they can roll with the cords; but for a double-acting machine this would be of no advantage, as a portion of the cords are falling when the remainder are rising. If the machine is very wide, or has to be set forward or back on the loom, there should be cross rollers of hard wood above the wires, at right angles to them, to prevent the bottoms of the hooks from being drawn either backwards or forwards, which might push their heads on or off the griffe knives.