JACQUARD

A peculiar and most ingenious mechanism, invented by M. Jacquart of Lyons, to be adapted to a silk or muslin loom for superseding the employment of draw-boys, in weaving figured goods. Independently of the ordinary play of the warp threads for the formation of the ground of such a web, all those threads which should rise simultaneously to produce the figure, have their appropriate healds, which a child formerly raised by means of cords, that grouped them together into a system, in the order, and at the time desired by the weaver. This plan evidently occasioned no little complication in the machine, when the design was richly figured; but the apparatus of Jacquart, which subjects this manœuvre to a regular mechanical operation, and derives its motion from a simple pedal put in action by the weaver’s feet, was generally adopted soon after its invention in 1800. Every common loom is susceptible of receiving this beautiful appendage. It costs in France, 200 francs, or 8 l. sterling; and a little more in this country. IMG:4147767755307473660_illo0657a.png:Jacquard loom IMG:4147767755307473660_illo0657b.png:Jacquard loom Fig. 566. is a front elevation of this mechanism, supposed to be let down. Fig. 567. is a cro section, shown in its highest position. Fig. 568. the same section as the preceding, but seen in its lower position. A , is the fixed part of the frame, supposed to form a part of the ordinary loom; there are two uprights of wood, with two cro -bars uniting them at their upper ends, and leaving an interval x y , between them, to place and work the movable frame B , vibrating round two fixed points a a , placed laterally opposite each other, in the middle of the space x y , fig. 566. C , is a piece of iron with a peculiar curvature, seen in front, fig. 566. , and in profile, figs. 567. and 568. It is fixed on one side upon the upper cro -bar of the frame B , and on the other, to the intermediate cro -bar b of the same frame, where it shows an inclined curvilinear space c , terminated below by a semi-circle. IMG:4147767755307473660_illo0658a.png:Jacquard loom D , is a square wooden axis, movable upon itself round two iron pivots, fixed into its two ends; which axis occupies the bottom of the movable frame B . The four faces of this square axis are pierced with three round, equal, truly-bored holes, arranged in a quincunx. The teeth a , fig. 570. , are stuck into each face, and correspond to holes a , fig. 573. , made in the cards which constitute the endle chain for the healds; so that in the succe ive application of the cards to each face of the square axis, the holes pierced in one card may always fall opposite to those pierced in the other. The right-hand end of the square axis, of which a section is shown in double size, fig. 569. , carries two square plates of sheet iron d , kept parallel to each other and a little apart, by four spindles e , pa ed opposite to the corners. This is a kind of lantern, in whose spindles, the hooks of the levers f f′ , turning round fixed points g g′ beyond the right hand upright A , catch hold, either above or below at the pleasure of the weaver, according as he merely pulls or lets go the cord z , during the vibratory movement of the frame B . E is a piece of wood shaped like a T, the stem of which prolonged upwards, pa es freely through the cro -bar b , and through the upper cro -bar of the frame B , which serve as guides to it. The head of the T piece being applied succe ively against the two spindles e , placed above in a horizontal position, first by its weight, and then by the spiral spring h , acting from above downwards, keeps the square axis in its position, while it permits it to turn upon itself in the two directions. The name pre is given to the a emblage of all the pieces which compose the movable frame B B . F is a cro -bar made to move in a vertical direction by means of the lever G , in the notches or grooves i , formed within the fixed uprights A . H , is a piece of bent iron, fixed by one of its ends with a nut and screw, upon the cro -bar F , out of the vertical plane of the piece C . Its other end carries a friction roller J , which working in the curvilinear space c of the piece C , forces this, and consequently the frame B to recede from the perpendicular, or to return to it, according as the cro -bar F is in the top or bottom of its course, as shown in figs. 567. and 568. I , cheeks of sheet iron attached on either side to the cro -bar F , which serve as a safe to a kind of claw K , composed here of eight small metallic bars, seen in section fig. 567. and 568. , and on a greater scale in fig. 570. J , upright skewers of iron wire, whose tops bent down hook-wise, naturally place themselves over the little bars K . The bottom of these spindles likewise hooked in the same direction as the upper ones, embraces small wooden bars l , whose office is to keep them in their respective places, and to prevent them from twirling round, so that the uppermost hooks may be always directed towards the small metallic bars upon which they impend. To these hooks from below are attached strings, which after having cro ed a fixed board m n , pierced with corresponding holes for this purpose, proceed next to be attached to the threads of the loops destined to lift the warp threads. K K , horizontal spindles or needles, arranged here in eight several rows, so that each spindle corresponds both horizontally and vertically to each of the holes pierced in the four faces of the square axis D . There are therefore as many of these spindles as there are holes in one of the faces of the square. IMG:4147767755307473660_illo0658b.png:Spindle Fig. 571. represents one of these horizontal spindles. n is an eyelet through which the corresponding vertical skewer pa es. o another elongated eyelet, through which a small fixed spindle pa es to serve as a guide, but which does not hinder it from moving length-wise, within the limits of the length of the eyelet. p , small spiral springs placed in each hole of the case q q , fig. 570. They serve the purpose of bringing back to its primitive position, every corresponding needle, as soon as it ceases to pre upon it. IMG:4147767755307473660_illo0658c.png:Jacquard pierced cards Fig. 572. represents the plan of the upper row of horizontal needles. Fig. 573. is a fragment of the endle chain, formed with perforated cards, which are made to circulate or travel by the rotation of the shaft D . In this movement, each of the perforated cards, whose position, form, and number, are determined by the operation of tying-up of the warp, comes to be applied in succe ion against the four faces of the square axis or drum, leaving open the corresponding holes, and covering those upon the face of the axis, which have no corresponding holes upon the card. Now let us suppose that the pre B is let down into the vertical position shown in fig. 568. ; then the card applied against the left face of the axis, leaves at rest or untouched the whole of the horizontal spindles (skewers), whose ends correspond to these holes, but pushes back those which are opposite to the unpierced part of the card; thereby the corresponding upright skewers, 3. 5. 6. and 8. for example, pushed out of the perpendicular, unhook themselves from above the bars of the claw, and remain in their place, when this claw comes to be raised by means of the lever G ; and the skewers 1. 2. 4. and 7., which have remained hooked on, are raised along with the warp threads attached to them. Then by the pa age acro of a shot of the colour, as well as a shot of the common weft, and a stroke of the lay after shedding the warp and lowering the pre B , an element or point in the pattern is completed. The following card, brought round by a quarter revolution of the axis, finds all the needles in their first position, and as it is nece arily perforated differently from the preceding card, it will lift another series of warp threads; and thus in succe ion for all the other cards, which compose a complete system of a figured pattern. This machine, complicated in appearance, and which requires some pains to be understood, acts however in a very simple manner. Its whole play is dependent upon the movement of the lever G , which the weaver himself causes to rise and fall, by means of a peculiar pedal; so that without the aid of any person, after the piece is properly read in and mounted, he can execute the most complex patterns, as easily as he could weave plain goods; only attending to the order of his weft yarns, when these happen to be of different colours. If some warp yarns should happen to break without the weaver observing them, or should he mistake his coloured shuttle yarns, which would so far disfigure the pattern, he must undo his work. For this purpose, he makes use of the lower hooked lever f′ , whose purpose is to make the chain of the card go backwards, while working the loom as usual, withdrawing at each stroke the shot both of the ground and of the figure. The weaver is the more subject to make mistakes, as the figured side of the web is downwards, and it is only with the aid of a bit of looking-gla that he takes a peep of his work from time to time. The upper surface exhibits merely loose threads in different points, according as the pattern requires them to lie upon the one side or the other. Thus it must be evident, that such a number of paste-boards are to be provided and mounted as equal the number of throws of the shuttle between the beginning and end of any figure or design which is to be woven; the piercing of each paste-board individually, will depend upon the arrangement of the lifting rods, and their connection with the warp, which is according to the design and option of the workman; great care must be taken that the holes come exactly opposite to the ends of the needles; for this purpose two large holes are made at the ends of the paste-boards, which fall upon conical points, by which means they are made to register correctly. It will be hence seen, that, according to the length of the figure, so must be the number of paste-boards, which may be readily displaced so as to remount and produce the figure in a few minutes, or remove it, or replace it, or preserve the figure for future use. The machine, of course, will be understood to consist of many sets of the lifting rods and needles, shown in the diagram, as will be perceived by observing the disposition of the holes in the paste-board; those holes, in order that they may be accurately distributed, are to be pierced from a gauge, so that not the slightest variation shall take place. To form these card-slips, an ingenious apparatus is employed, by which the proper steel punches required for the piercing of each distinct card, are placed in their relative situations preparatory to the operation of piercing, and also by its means a card may be punched with any number of holes at one operation. This disposition of the punches is effected by means of rods connected to cords disposed in a frame, in the nature of a false simple, on which the pattern of the work to be performed is first read in. These improved pierced cards, slips, or paste-boards, apply to a weaving apparatus, which is so arranged that a figure to be wrought can be extended to any distance along the loom, and by that means the loom is rendered capable of producing broad figured works; having the long lever G placed in such a situation that it affords power to the foot of the weaver, and by this means enables him to draw the heaviest morintures and figured works, without the a istance of a draw-boy. The machinery for arranging the punches, consists of a frame with four upright standards and cro -pieces, which contains a series of endle cords pa ing under a wooden roller at bottom, and over pulleys at the top. These pulleys are mounted on axles in two frames, placed obliquely over the top of the standard frame, which pulley-frames constitute the table commonly used by weavers. IMG:4147767755307473660_illo0660.png:Endle cord In order better to explain these endle cords, fig. 574. represents a single endle cord 1, 1, which is here shown in operation, and part of another endle cord 2, 2, shown stationary. There must be as many endle cords in this frame as needles in the weaving-loom. a is the wooden cylinder, revolving upon its axis at the lower part of the standards; b b , the two pulleys of the pulley-frames above, over which the individual endle cord pa es; c is a small traverse ring. To each of these rings a weight is suspended by a single thread, for the purpose of giving tension to the endle cord. d is a board resembling a common comber-bar, which is supported by the cro -bars of the standard frame, and is pierced with holes, in situation and number, corresponding with the perpendicular threads that pa through them; which board keeps the threads distinct from each other. At e , the endle cord pa es through the eyes of wires resembling needles, which are contained in a wooden box placed in front of the machine, and shown in this figure in section only. These wires are called the punch-projectors ; they are guided and supported by horizontal rods and vertical pins, the latter of which pa through loops formed at the hinder part of the respective wires. At f are two horizontal rods extending the whole width of the machine, for the purpose of producing the cro in the cords; g is a thick bra plate, extending along in front of the machine, and lying close to the box which holds the punch-projectors ; this plate g , shown also in section, is called the punch-holder ; it contains the same number of apertures as there are punch-projectors, and disposed so as to correspond with each other. In each of these apertures, there is a punch for the purpose of piercing the cards, slips, or pasteboards with holes; h is a thick steel plate of the same size as g , and shown likewise in section, corresponding also in its number of apertures, and their disposition, with the punch-projectors and the punch-holder. This plate h , is called the punch-receiver . The object of this machine is to transfer such of the punches as may be required for piercing any individual card from the punch-holder g , into the punch-receiver h ; when they will be properly situated, and ready for piercing the individual card or slip, with such holes as have been read in upon the machine, and are required for permitting the warp threads to be withdrawn in the loom, when this card is brought against the ends of the needles. The proce of transferring the patterns to the punches will be effected in the following manner. The pattern is to be read in, according to the ordinary mode, as in a false simple, upon the endle cords below the rods f , and pa ed under the revolving wooden cylinder a , to a sufficient height for a person in front of the machine to reach conveniently. He there takes the upper threads of the pattern, called the beard , and draws them forward so as to introduce a stick behind the cords thus advanced, as shown by dots, for the purpose of keeping them separate from the cords which are not intended to be operated upon. All the punch-projectors which are connected with the cords brought forward, will be thus made to pa through the corresponding apertures of the punch-holder g , and by this means will project the punches out of these apertures, into corresponding apertures of the punch-receiver h . The punches will now be properly arranged for piercing the required holes on a card or slip, which is to be effected in the following manner. Remove the punch-receivers from the front of the machine; and having placed one of the slips of card or pasteboard between the two folding plates of metal, completely pierced with holes corresponding to the needles of the loom, lay the punch-receiver upon those perforated plates; to which it must be made to fit by mortises and blocks, the cutting parts of the punches being downwards. Upon the back of the punch-receiver is then to be placed a plate or block, studded with perpendicular pins corresponding to the above described holes, into which the pins will fall. The plates and the blocks thus laid together, are to be placed under a pre , by which means the pins of the block will be made to pa through the apertures of the punch-receiver; and wherever the punch has been deposited in the receiver by the above proce , the said punches will be forced through the slip of pasteboard, and pierced with such holes as are required for producing the figured design in the loom. Each card being thus pierced, the punch-receiver is returned to its place in front of the machine, and all the punches forced back again into the apertures of the punch-holder as at first. The next set of cords is now drawn forward by the next beard , as above described, which sends out the punch-projectors as before, and disposes the punches in the punch-receiver, ready for the operation of piercing the next card. The proce being thus repeated, the whole pattern is, by a number of operations, transferred to the punches, and afterwards to the cards or slips, as above described. JADE; axe-stone; ( Nephrite , Ceraunite , Fr.) is a mineral commonly of a greenish colour, compact, and of a fatty lustre. Spec. grav. 2·95; scratches gla , is very tough; fuses into a white enamel. Its constituents are, silica 50·5; alumina 10; magnesia 31; oxide of iron 5·50; oxide of chrome 0·05; water 2·75. It comes from China, is used among rude nations for making hatchets; and is susceptible of being cut into any form.