Page:The American Cyclopædia (1879) Volume XVI.djvu/545

 WEAVING 525 and moving a picking cord, or by means of two levers with short cords at the two sides ; motion being in either case communicated to these at the proper moments by the mecha- nism. Thus, in the use of the single cord, the driving shaft in each loom, which in all cases derives its power through a band from the common shaft directly impelled by the engine, imparts motion to a second shaft running across the loom below it ; while on this two rollers are so affixed, that one of them at each half turn of the shaft suddenly strikes down a roller on one side of the whip lever, and so, shorten- ing another cord at this part, draws the lever and picking cord with a sharp jerk in the cor- responding direction ; the cord, acting on pick- ers as before explained, gives the throw to the shuttle. The stroke of the batten or lay, beat- ing up the weft threads, is accomplished by means of cranks on the driving shaft, which so connect with arms projecting from the upright pieces of the batten (in these looms pivoted to the frame below) as to draw the batten for- ward after every throw of the shuttle. The connection of the shafts in the loom with each other, and with the cloth beam, to which a slow movement is imparted, is by toothed wheels, of such size as to give to each the required rate of speed. Among the late improvements in the power loom are those by which the loom is stopped when the weft thread breaks or is absent, when the driving band is shifted, and when the shuttle does not get clear of the shed ; that in which the tension of the warp is ob- tained, not by a weight, but by springs fixed to the framing; and that of Mr. Ingram (1860) for resupplying the loom with weft as often as the bobbin or cop is exhausted, or when the thread is only broken. The expense of mate- rial and time in preparing the cards for the Jacquard apparatus, which for the heaviest work must be of sheet iron, and for all intricate patterns very numerous, has always constituted the most serious drawback upon the desira- bleness of that method. Thus, an elaborate damask design has required 4,000 cards and 400 needles, at a cost of about $120, and five weeks' labor of a man in setting up ; while a single design has been known to require 20,000 cards, at a cost of $600, and time equal to a year's labor of one man. With a view to reduce greatly these expenditures, M. Bonelli first constructed in 1854, and has since much im- proved, his " electric loom." In this, the cards of Jacquard's apparatus are superseded by an endless band of paper covered with tin foil, intended to serve as an electrical conductor; accordingly, the unperforated portions of the cards are here represented by non-conducting patches of black varnish, laid on with a brush. The band passes steadily along, under the points of rows of metallic rods or teeth. Each of these teeth connects with a small coil or helix, within which is a soft-iron bar. A frame capable of swinging slightly is situated in front of the ends of these bars, having a plate in it perforated with a corresponding number and order of holes, within and through which as many iron rods abutting at one end against the bars already named can move with a little fric- tion, like as many piston rods through stuffing boxes. The tin foil band being put in connec- tion with a galvanic battery, with the other pole of which the remote ends of all the helices connect, all the metal teeth at a given time resting upon the bare foil conduct portions of the current, render the bars in their helices magnets, and by their action withdraw the corresponding rods out of the plate, leaving so many holes open; while the rods answering to the teeth that are on the varnished portions of the foil remain in and close the other holes. In this way, this single plate is made to serve for the endless succession of Jacquard cards ; the needles entering these holes determining as before what warp threads shall be raised. By means of insulated strips of foil running along the back of the tin foil band, and con- nected with certain portions only of its face, separated by narrow insulating breaks, differ- ent colors or sorts of weft can be successively worked into the piece, according to the strips of foil successively put in connection with the battery. In another improvement of the Jac- quard loom, a sheet of prepared paper punched Avith the proper apertures is substituted for the cards of the old machine ; this paper being in form of a continuous band, only three fourths of an inch wide, so that the weight of the new is to that of the old band as but 1 to 11. The arrangement is also such as permits the 400 spiral springs in connection with the needles in the old machine to be dispensed with. Thus the wear and tear due to the resistance of these is done away with, and fine and light wires are introduced in lieu of the heavy ones previously employed. Various additions have also been made to the Jacquard loom by Barlow, Taylor, Martin, and others. American inventions in connection with the improvement of the power loom have been very numerous, but compara- tively few radical changes have been introduced. In 1857 Mr. E. B. Bigelow of Boston patent- ed a method of weaving pile fabrics double, by means of transverse intersecting pile wires woven between the two fabrics so as to keep them properly apart, with movement at the same time of two shuttles, and an arrangement connecting each shuttle with the shipper or disconnecting lever of the loom, so that, when the filling fails in either shuttle, the loom is thrown out of gear. An invention by Joseph Fish of New York was patented Oct. 26, 1875, which is especially applicable to the weaving of broad silk with figures of different colors and of various patterns. Its main object is to produce a power loom which shall not only provide for the control of the Jacquard ma- chine or pattern-controlling device, but also " for the driving of the supplementary shut- tles, and otherwise actuating them or such por- tions of their attachments as require to be