In this loom the warp is not stretched directly from the irarp-bram. I, to the cloth-roll, 2, as in the hand-loom, but is carried nimard at an angle from the warp-loam over a support ealled the whip-roll, a, from which it is stretched, through the harness and rec.,' —NV hieh are held firmly in the lathe by the hand-rail, h to the breast-beam, (1, over which the cloth passes downward to the cloth roll; it will he seen that by this arrangement the loom is made to take up much less space than it would in any other form. The modern power-loom also combines a number of appliances which were made necessary by the application of power and which make it possible for the weaver to keep a number of looms running, while the hand-weaver could run but one. Of these special attachments may he mentioned the filling-stop motion, which automatically causes the loom to stop. should the filling become exhausted in the shuttle, or break; the shuttle-protector, which is so arranged that should the shuttle for any reason fail to reach its place in the shuttle-box to which it has been driven, the loom is stopped and held so that the lathe will not cause any of the warp threads to be broken should the shuttle happen to be caught in the shed and the loom not stop; the automatic take-up and het-off motions, which let the warp unroll from the warp-beam at the re quired speed and wind up the woven cloth automatically, regulating the num ber of filling-threads to the inch. There has also recently been perfected the warp stop motion, which is arranged to act on the driving motion of the loom and to cause the loom to stop immediately should one of the threads of the warp become broken.
As labor is a large item in the cost of production, much experimenting has been done to perfect a loom which would either change an empty shuttle for a full one automatically• or else furnish a full bobbin of yarn to the empty shuttle with out the loom stopping. The ,Vorthrop loom, Fig. 3, is the only one which has proved practical enough to be installed in any number as yet ; there were over 70.000 of these in opera tion at the beginning of 1903, though the inven tion only dates from IS94. In this loom the loom-shuttle and one of the shuttle-boxes are made without any bottom, and above this shuttle-box is arranged a magazine or hopper which is kept supplied with a large number of full hol,hins; as the tilling in the shuttle runs out. the mechanism of the loom so nets on one of the fresh bobbins of yarn that it is forced downward into the shuttle and in turn forces the empty bobbin out through the holes in the bottom of the shuttle and the shuttle-box. and the loom continues to run as if no change had been made.
The above principle has as yet only been ap plied to looms weaving the simpler kinds of cot ton fabrics, and only to weave fabrics when there is to be but one filling in kind or color through out the warp. This loom is almost invariably supplied with the warp-stop motion, already men tioned, and weavers are running sixteen to twenty of them on print-cloths, instead of eight of the common loom.
Looms for fabrics which require not more than five harnesses to produce the weave are generally called cam-looms, for the reason that the Harness is operated by the action of cams on the loom treadles. For fabrics which require more than five harnesses, special fancy-looms are arranged; these usually have a head-motion—a mechanism which regulates the pattern to be woven and may control the movement of as many as thirty har -lobbies and witches are special head-mo tions.
Looms for the weaving of figured patterns are fitted with the Jacquard machine, an appliance invented originally by Joseph ,Nlarie ,Tacquard (q.v.). an ingenious Frenchman. He succeeded in producing a machine whereby an ordinary workman could with comparative ease produce the most beautiful patterns in a style which had previously only been accomplished with great patience, skill, and labor.
The machine, Fig. 4, may be applied to almost any style of loom and is simply a head-motion to control the loom-harness and to form the shed. It consists of a set of perpendicular hooks, AB, AB, connected with and controlled by a set of horizontal needles, C, C: above these hooks— which are placed in four, six, eight. or twelve rows to the machine. which may have from 200 to 1200 or more books—is a set of knives, T. I, called a griffe, with one knife for each row of hooks. To the lower extremity of each hook is attached a loop of twine called the nee•-cord, d, which is passed through the bottom-board, 2, 2, having perforations immediately under each hook; from the neck-cords hang the strings, E, E, and there may be from one to half a dozen of these to each hook. These leash-strings are passed through a board placed hori zontally a little above the warp to be woven, called the comber-board, 3, 3, having rows of per forated holes to cor respond with the number of warp threads. This board is divided into sec tions, and in what is called a straight tie-np of the harness there are as many leash-strings to each hook as there are sections; in the il lustration given there arc four sec tions.
Below the comber hoard and at the place where the shed is to be formed each leash-string is sup plied with an eye called a mail, F, through which the warp-thread to he controlled is passed ; and to the lower end of each string is attached the lingo, g, g', a small weight to draw it down. The neck-cord, leash-strings, mail, and lingos make up the Jacquard harness. The needles are held in place by a needle-board, 4, 4, which is made with rows of holes through which the ends of the needles pass about eighths of an Mob, pointing to the front, and a spring-box, 5. 5, at the back having a series of spiral springs. one for each needle, which, ing the needle to the front, keep the hooks in a vertical position. The pattern to be woven is regulated by an endless chain of heavy board cards, L, L, L, which pass over a square prism, called the eylifider. 0 P Q B, which is caused to revolve intermittently by swinging in and out like a pendulum in an are, the cord of which is little longer than the cylinder is square; as the cylinder swings out the catch, x, engages one of the pins, 0, Q, PI, causing the cylinder to make a quarter revolution, bringing a new card into position. The cylinder is perforated with rows of holes to correspond with the needles of the machine, and when the bare cylinder is allowed to come in contact with the needle-board, the needles projecting- through the latter readily enter the perforations without moving the hooks; hut the pattern-cards are so perforated that for all warp-threads that are to he raised above the filling in the woven pattern holes are cut for the needles which control them to pass through, the holes being cut to superimpose the holes in the cylinder; but holes are not cut in the cards for the needles controlling those warp threads which are not to be raised.