The jacquard machine was introduced into England about 1818 and came into general use from 1824 to 1832. It was introduced into Scotland about 1824. Fig. 16 is a representation of the early form of jacquard, and of course intended for hand-loom work. Although the present machines for power-loom work are very different in make, nearly all the working parts as here used are to be found in different machines at present working, or still being made, though the best machine makers have adopted newer and better principles for fast working and withstanding wear and tear. Fig. 16a is a view of the interior of the machine. The working of the machine will be explained further on; only those parts that will not be given in the new machines will now be noticed. The griffe or frame for raising the hooks is lifted by the straps A, A, Fig. 16, which are attached to the pulleys B, B, and a cord C over a pulley on the same shaft as B, B, is attached to a treadle beneath the loom. As the weaver presses down this treadle the griffe is raised, and when the treadle is released the griffe falls of its own weight. The cylinder is moved out and in by the pulley E, fastened on the bent iron bar, attached to the frame which carries the cylinder, when the griffe rises and falls. D, D is a frame which lies in the turned-up portion of the hooks; only a few hooks are shown, and the outer bars of the frame. There should be a bar in the frame for each row of hooks. This frame rises up and down with the hooks, the turn on the ends of which must be of such length that when the frame is raised by the hooks lifted by the griffe, it will not be raised out of the turns on those that are left down. This frame is for the purpose of preventing the hooks from turning round, so that the turns on the It might be interesting to describe the various changes and attempted improvements that have been made on the original jacquard, but it would take up too much space, and many of them are of more historical A jacquard machine is simply a shedding motion by which a great variety of sheds can be formed; the larger the machine, or the greater the number of hooks it contains, the greater is the variety of shedding that can be produced by it. If a jacquard is made small, with, say, from 16 to 48 hooks, it is called a dobby or shedding motion, and is used for working shaft mountings; but the ordinary jacquard machines have from 200 to 600 hooks, which have long cords, called the harness, connected to them, no shafts being required, as each hook has only a few cords tied to it, which can be raised independently of the others. The fewer the cords that are tied to each hook, the greater is the variety of shedding that can be made on the same number of warp threads, till, when there is but one cord to the hook, any thread or any number of threads can be raised independently of any of the others. Jacquards may be divided into four classes—viz. single-acting, double-acting lift, double acting with double cylinders, and twilling jacquards; and besides these there are several other varieties made for special purposes. The single-acting is the real jacquard, and much the simplest machine. It has the disadvantage which all single-acting shedding motions have—viz. that one shed must be closed before the following one begins to open. This is on account of the same lifter having to open each shed; it must bring down the set of hooks that are raised, and then raise the next set. This constitutes the true jacquard lift; and while it makes a clear shed, and is desirable for some purposes, it is generally considered the most imperfect form of shedding—that is, so far as the making of a good cloth is concerned. It is not suitable for making a heavy, well-covered cloth, nor for working at a high speed, 120 to 140 picks per minute being a very good speed to drive it. A single-acting jacquard is a very simple machine, and when properly made should give very little trouble in working, particularly if the motions are properly set in relation to each other, and if such methods of working are adopted as will cause the least wear and tear on it. In whatever way jacquards are made, the principle of working is much the same. There are a number of upright hooks set in a frame; attached to each hook is a horizontal wire or needle, one end of which is pressed upon by a spring, which keeps both it and the hook steady and in position, while the other end, or point, passes through a perforated plate, beyond which it projects about half an inch (see Fig. 16a). To lift the hooks there is a set of bars or knives arranged in a frame, just below the heads of the hooks; this frame is called the ‘griffe’ or ‘brander,’ and if raised would draw all the hooks up with it. What hooks will be lifted for each shed is regulated by perforated cards being pressed against the points of the needles. A perforation in the card allows the point of a needle to pass through and the hook to be raised; but where there is no perforation the card comes against the point of the needle, pressing it back, and holding the head of the hook clear of the blade of the griffe, so that the griffe will pass without raising the The other end of the lever is connected to a crank on the crank-shaft In hand-loom machines the griffe is frequently pushed up from below instead of being drawn up from the top as is shown in Fig. 17. The method of doing this is similar to that given for lifting the griffes of twilling jacquards. F (Fig. 17) is called the cylinder or barrel, evidently taking its name from the round cylinders or barrels used in the old machines, but is in reality a square prism. It is made of wood, and perforated on each side with a set of holes—a hole for each needle in the machine; its use is to draw round the chain of cards and press each one against the needles, or horizontal wires, in the machine. In order to keep the cards firmly on the cylinder, flat steel springs are sometimes used, as shown, attached to the top rail of the frame which holds the cylinder; and there are also steel wires which pass down in front of the cylinder over the ends of the cards. These springs are useful when only a small number of cards is used and the machine driven quickly; with a large set of cards, where there is plenty of drag on them from their own weight, they are not necessary, and but seldom used; but they are in common use in the Yorkshire districts. It will be seen from the illustrations (Figs. 17 and 18) that the cylinder hangs in a frame suspended from the top of the machine; this is called the swing or batten motion, to distinguish it from the horizontal or sliding motion which is shown at Fig. 20 (No. 1) and in Fig. 27. The swing motion is the simpler of the two, and is cleaner, requiring less oil; but the sliding motion is steadier, and does not swing the cards so much, consequently is more suitable when the cylinder has to travel quickly. The swing motion also requires the machine to be higher; with a slide motion the frame is usually cut off a little above the griffe. The cylinder has to travel out and in when the machine is working, so that it may be turned round and bring a fresh card against the needles for each shot. There are many methods of accomplishing this, which may be divided into two classes—viz. independent motions, or those which are driven from the loom independently of the machine; and self acting motions, or those which drive the cylinder out and in through the rising and falling of the griffe. The latter are the simpler, but the former are much better, causing less wear and tear on both the cards and machine, as will be explained further on. It will be seen in Fig. 18 that as the cylinder travels out it will be caught by the hook K1, and turned round; the head or lantern of the cylinder is made of iron, as shown, so that the hook, or shears, will take a firm catch on it. To prevent the cylinder from turning more than one card at once, and to keep it steady so that it will always come in fair against the needles, it is held firm by a hammer pressed on it by a spring. This pressure is applied in different ways, one of which may be clearly seen in Fig. 17, and another in Fig. 27. When taking out the cylinder, or wanting to run it round quickly to draw over a number of cards, the hammers can be held up by a hook or sliding catch, which should be fitted to the machine for the purpose. One of the best independent motions for driving the cylinder is shown in Fig. 17; and that shown in Fig. 18 is also a very good one for small machines, perhaps the most convenient that is made; but the former is much stronger. In Fig. 17 a connecting-arm from the frame of the cylinder is attached to the lever B. The connecting-arm should The lever B is on a horizontal shaft, bracketed to the frame of the loom, or to the beams on which the machine rests; or some machines have bearings attached to their framing for it. There is, of course, a lever, as B, and a connecting-arm at each side of the machine. There is another lever on the end of the shaft, at right angles to B, which is connected with an eccentric on the crank-shaft of the loom by a rod, C, in the same way as the rod C is connected with the eccentric in Fig. 18. The eccentric can be set to bring the cylinder against the needles at any required time, independent of the lifting motion of the machine, which cannot be done when the self-acting motions are used. The larger the eccentric, the greater dwell the cylinder will have against needles. The method of working the cylinder in Fig. 18 is somewhat similar, and can easily be seen; but it will be observed that a good deal of pressure will be put upon the studs on which the cylinder frame, or batten, hangs, particularly when the cylinder is being pressed in, as this is effected by drawing down the lever L; however, in a light machine this does not matter much. The principal feature in this motion is the escapement apparatus for the purpose of disengaging the cylinder from its connection with the driving eccentric when it is required to turn some of the cards back. Fig. 19 (Nos. 1 and 2) shows this arrangement. The motion is not quite the same as that given in Fig. 18, but is on the same principle, and one may be easily understood from the other. In Fig. 18 the latch G Instead of the eccentric and crank for driving the cylinder and raising the griffe being as they are shown in Fig. 18, though a plan frequently in use, it is neater, and perhaps better, to have the eccentric at the back of the fly-wheel, and the fly-wheel either cast with one half solid, or have a plate fastened across two or more of the spokes, to which the connecting-rod can be attached with a bolt fastened in a slot. The amount of lift can be increased or diminished, either by shifting the top of the connecting-rod along the lever G (Fig. 17), or by increasing or reducing the throw of the crank at the fly-wheel. Self-acting motions actuate the cylinder through the rising and falling of the griffe without requiring any special connection from the loom. One of the most convenient of these is that frequently used on hand-loom machines, and known as the S iron or swan-neck motion. It is shown in Fig. 19a (No. 1), and another form of it on a swing cylinder motion is shown in Fig 16. D is the swan-neck or S iron. In the groove in it a roller stud on the griffe frame travels, sliding in and out the cylinder A as the griffe falls and rises. E is the slide bar, which may be flat or round; if round, there must be some means of keeping it from turning in its bearings, which is generally accomplished by having a crossbar bolted across the two slide bars behind the machine. No. 2, Fig. 19a, is a motion for the same purpose, but consists of a The connecting-bar H is in two parts, slotted and bolted together at H to admit of regulating the position of the cylinder. No. 4 is a motion on a different principle; it is a French motion. It will readily be seen that the cylinder is driven out and in by the toothed wheel, which is wrought by a rack on the slide rod E. This slide rod works outside the framing of the machine, as is common in the French machines. One point must be observed about these motions—viz. that they must have a certain amount of dwell at the bottom of the stroke, or when the cylinder is in. The reason of this dwell will be explained further on, but the method of obtaining it may be given here. In the swan-neck motion (No. 1), any desired dwell can easily be obtained at either top or bottom by the length of the slot that is in a vertical direction, as when the stud is passing through this portion of the slot no motion is given to the cylinder. In the lever motions Nos. 2 and 3, as well as in No. 4, the dwell is got by the levers or arms passing the centres; in Nos. 2 and 4 it is by the lever or arm H passing the back centre, which may be considered as a crank; and in No. 3 it is the short lever C passing the centre that gives the dwell. Fig. 20 is a view of the interior of a single-acting jacquard machine with the framework removed; only one row of hooks and needles are given, to avoid confusion. The blades or knives of the griffe, with a support running across their centres, are shown at B. A is the face-plate or needle board, sometimes made of iron, but better to be of hard wood. C is the spring-box, the detail of which is given in Fig. 24. E, E1 are the hooks, and F, F1 the needles. D is the grating through which the hooks pass, and are supported by it. It will be seen that the hooks and needles are arranged in rows of eight: a 400 machine would have 50 or 51 of these rows in it; 500 machines are usually arranged in rows of 10, and 600 machines in rows of 12. The hooks In the old Jacquard, given in Figs. 15 and 16, the hooks are shown resting on a perforated board, and it was mentioned that in order to prevent them from turning round a frame lay in the turned-up portion of the hooks. The grating in Fig. 20, through which the turned-up bottoms of the hooks pass, readily accomplishes this object. Sometimes flattened hooks are used, as in C (Fig. 23), with the needles twisted once or twice round the hooks; this makes a firm arrangement, but if anything goes wrong with a hook it is not easy to get it clear of the needle. When the needles were made with a full twist or loop on them, as at B, the same was the case; they are now usually made as at A, and if arranged in the machine as in Fig. 20, there is no danger of the hooks sliding out of the recess in the needle, and if a hook gets bent or broken, it can be taken out and replaced by a new one without disturbing the needles. Fig. 16 shows how the needles press against the springs in the spring-box, which is much the same as that at present in use. Fig. 24 is the present arrangement. No. 1 gives a plan of the end of a needle, B. C C is the horizontal wire which supports it as shown in section at C C in No. 2. D (No. 1) is a section of the vertical wire shown at D D (No. 2), which passes through the loops or eyes on the ends of the needles, and keeps the springs from shooting them too far forward. A (No. 2) is a wire which passes down at the outside of the box over the ends of a row of springs, so that by drawing out this wire any of the springs can be drawn out without taking off the spring-box, as the springs pass through the box. The springs should be strong enough to keep the hooks and needles steady, but if unnecessarily strong they give the card and cylinder unnecessary work. In some machines there is no spring-box. The hooks are made double, as shown in Fig. 25, and rods, as a, a, run along between the rows of hooks; the spring of the double wire keeps the hooks steady. There is a clap-board used, similar to that in the French draw loom, (Fig. 13), which is pressed against the needles with springs; this board is connected with the face-plate by a bar at each end, forming a frame. The needles do not project much through the face-plate, but when the cylinder is pressed against it, it slides back on the needles, and presses In working, the card cylinder must be so set that it will come forward fair on the needles—that is, that when it comes forward the points of the needles will enter fair into the centres of the holes in it. For the purpose of setting it there must be provision made in the fittings so that it can be moved laterally or vertically. In the swing motion the frame can be moved laterally by means of the two screw studs on which it hangs. C, Fig. 27, shows the bearing on which the stud of the cylinder revolves. This bearing can be raised up or down in the frame R—a side view of which is given at S—by slackening the A method commonly adopted by tacklers or tuners to see that the needles are perfectly fair in the centres of the holes in the cylinder, is to rub their fingers on some dirty oil, and touch over the points of the needles with it. They then bring in the cylinder against the needles with a card on it, in which about half of the holes are cut. The points of the needles mark the card where there are no holes, and it can easily be seen whether the mark is in the centre of where a hole should be, or not. One of the best bearings and attachments for a cylinder with a horizontal slide motion is given in Fig. 26. D is the bearing for the cylinder E, and C the bolts for setting it. F F is the bracket which holds the hammer and bearings, which can be set in position on the slide bar B by the bolt A. I is the hammer held down by the spring H attached to the rod G. The cards are kept in position on the cylinder by pegs or studs, originally made of wood, and driven into the cylinder. Now they are made of brass, and set in a slotted bracket, so that they can be shifted in order to have the holes in the cards corresponding exactly with those in the cylinder. The pegs should also be set on springs, so that if a card gets off them, and between them and the needle plate, they will yield or sink into the cylinder, and not break the card. In all good machines they are made in this way. When the motion for driving the cylinder is not fitted with an escapement for the purpose of turning back the cards, it is necessary for the convenience of the weaver to have a motion on the machine for the purpose. Figs. 28 and 29 show two varieties of these motions. A is the cylinder head; C, the catch for reversing the cylinder; F, the spring for returning the catch to its position; E, a cord which hangs down, with a knob on the end of it, in a convenient position for the weaver to catch and work the motion. In Fig. 28 the motion is on the opposite side of the machine to the shears, but might be on either side, and the weaver has to raise the shears to turn the cylinder, which she can Sometimes the cylinder may not be completely turned by the shears when the machine is working, by reason of the cards catching, or if the shears are too long, or it may arise from other causes. In this case the cylinder would come in with one corner against the needles, and be pressed heavily against the needle plate. Some of the levers would probably be broken, or the cylinder might be shot out of its bearings and fall, breaking the yarn, or perhaps injuring the weaver. To avoid this, small snecks, as at H, Figs. 28 and 29, are set so that when the cylinder is square it will pass over them; but if turned angularly its lower edge will catch on the point of the sneck, as the cylinder is coming in, and turn it square. The sneck is held up The setting of a jacquard machine for working consists in adjusting the cylinder motion so as to bring in the cylinder at the proper time, and press it sufficiently close against the face-plate to keep the hooks clear of the knives of the griffe, without pressing it too close; and regulating the lifting of the griffe to suit the time for shedding, and to give the size of shed required. The shed must be open for the shuttle to pass through; the time for picking is when the cranks of the crank-shaft of the loom are at the bottom centre, therefore the shed should be almost fully open at this time. The lifting of the griffe can be made a little earlier or later to suit circumstances, but very little alteration can be made, as it takes a full revolution of the crank to raise and lower the griffe. Further consideration will be given to jacquard shedding after double-acting machines have been explained. The motion for working the cylinder, if an independent one, should be rigid and strong; for if there is any spring in it, though the cylinder may be brought in sufficiently close when there is much cutting on the card, if a blank card or one with very little cutting on it comes on, the extra pressure on the needles, especially with a large machine, may prevent it from getting in sufficiently close to clear the hooks from the griffe. With self-acting motions there may sometimes be some trouble in this way, as the weight of the griffe may not be sufficient to press in the cylinder. In this case the griffe may be weighted, or may be allowed to drop quicker, or the lifting rod and lever may be made to assist in pressing it down somewhat. Before starting the machine the needles should be examined to see The driving of heavy single-acting jacquards will be further considered under Twilling Jacquards. When any of the hooks or needles in a jacquard get bent or broken, they can easily be straightened, or taken out and replaced by others. By putting a thin blade of iron or wood down through the needles alongside of the hook to be replaced, and springing open the passage, the old hook may be drawn out and a new one put into its place. The tail cord must, of course, be cut off the bottom of the hook, and a new one tied on. For changing a needle take off the spring-box and draw up the pin which fastens the row of needles at the back; then the needles in this row may be taken out till the defective one is reached, and the row made up again; or, the old one may be renewed without taking any of the others out. A flat blade is used to slide through the hooks and keep clear the place for the needle to be put in. Card Frames.—The cards for jacquard work are usually hung on a frame as O, Fig. 18, wires sufficiently long to catch on both sides of the frame being tied to the lacing of the cards. The number of cards between each wire may vary to suit the space and the quantity of cards. Sixteen to twenty suit very well, the former for small and the latter for larger sets, and for very small sets twelve or fourteen might be more convenient. The frame may be made of round iron rod, or of flat or bar iron, and should be of the shape shown in the sketch, and not semicircular, as is usually the case, which presses the cards together in the centre; almost flat at the bottom, with just enough of a slope to make the cards slide back, is much the best. Of course, for a few cards it does not matter much what shape it is. P (Fig. 18) is the frame for the rollers over which the cards travel to the cylinder. They should be so sloped as to make the cards travel up nicely with sufficient drag on them, and not too much; on this depends a good deal the As has already been said, the nature of the shedding of a single-acting jacquard is objectionable for speed in working, for ease on the yarn, and for heavy work, or for well-covered work. The jacquard harness is levelled so that the yarn is all sunk, and the shed is entirely a rising one; it can easily be understood that when the griffe rises to open one shed, it must again fall before it can begin to rise to form the next shed. Now, mostly all tappet motions, and a great many dobbies or shedding motions, either have the yarn springing up and down from the centre, or have one portion rising and the other portion falling at the same time, so that in them the second shed could be open at the same time that the griffe in the single-acting jacquard had fallen to begin to rise the second shed; but as this would be much too soon, It has been attempted to work the single-acting jacquard on the centre-shedding principle, and machines are at present being made in France of this class. It is only necessary to let the board on which the upright hooks rest fall at the same time that the griffe is rising in order to accomplish what is required, and the method of working is good, and would suit well in dobbies where the heddles can be taken firmly down. But in the jacquard the drawback is in the harness: the constant rising and falling causes a vibration in it, and does not admit of nearly so firm work as when the rising shed alone is used. One of these machines is shown in Fig. 30; they are a very compact and neatly made machine, and contain a much greater number of hooks than one of the English machines. Fig. 26 gives one of the hooks in this machine, and the way in which it acts is there explained. It will be seen that the frame for the cylinder is inverted; F is the face-plate or needle board as it rests when the cylinder is not pressing against it, being held in this position by the spring H pressing on a stud on the bar I, which extends from the face-plate to the clap-board G. The cylinder frame is driven by a rod, C, connected with a lever. E, This is a very good motion, perhaps could not be surpassed for the purpose, but, as I said before, has the objection which all similar contrivances for the purpose must have—viz., causing too much vibration in the harness. All the cords constantly dancing up and down causes an unsteadiness and swinging that is not to be found in the ordinary jacquard harness. These machines have sixteen rows of needles in them, which are much closer set together than those in this country, and give a large number of hooks in a small-sized machine, which is a great advantage when extensive patterns are required. In this machine the half-card contains 440 holes, or 880 holes to the full or double card. The pitch is shown at A, Fig. 31, which represents the end of one of these cards, and a piece of one of the usual 8-row cards as here used is shown at B for contrast, the black dots in both cases representing holes. These machines have not been adopted here, nor is it likely that they will be, although they are said to work well in France. They have been tried here, and the difficulty lay in setting the cards properly so as to act correctly on the needles, and keeping them so for any length of time. The least contraction or expansion of the paper, or any irregularity in the cutting, any bend in the points of the needles, or, in fact, anything but perfect exactness, interferes with the working: there is too great compactness in the machine, and in the ordinary wear and tear of work a little allowance is necessary for success. Considering that these are working, it would appear that the pitch and size of the holes in our cards are unnecessarily large, except where The method already mentioned of getting over the disadvantage of the single-acting jacquard is not likely to gain general favour, and is not required, as it is surpassed by the double-acting jacquard, or that in which there are two griffes, one rising when the other is falling, forming a counterpoise as well, making the shed more after the principle of ordinary tappet shedding. In a loom fitted with a single-acting jacquard, if there is much weight to be lifted, it will turn round the loom so that it will rest in no position but with the griffe down, and this is frequently of so much annoyance to the weaver as to necessitate a counterpoise being applied to balance it. Sometimes weights are used, and sometimes springs. With the double-acting lift nothing is required, and this was first used in Cross’s counterpoise harness (about 1816). In the double-lift machine there are double the number of hooks Fig. 35 shows how the raised hooks can be allowed to yield to the pressure of the needles. A, B, C, D are four hooks connected with two needles, 1 and 2. When the hook A is raised, if B, which raises the same warp—as will be seen by the connection of the tail cords with The tail cord consists of two pieces of cotton cord, one fastened to each hook of a pair, then the two ends are together tied to the bunch of neck twines that are to hang from these hooks, as shown in Fig. 35, and at A, Fig. 36. When one hook is raised and the tail cord drawn up with it, the other portion of the tail cord, which is tied to the other hook, is slackened—as shown at A, Fig. 36—which causes a certain amount of friction on them. Also, when one hook of the pair is falling with the descending griffe, and the other hook rising, the pluck occasioned thereby on the cords, when the hooks are passing at the centre, has a tendency to wear and break them. Although this does not occur when the lingoes are of a moderate weight (18 to 25 per lb.), and when only a few neck twines are tied to each tail, yet when a large number of neck twines (say 20) are tied to each tail, with weighty lingoes, as may frequently be the case in weaving small patterns on This patent works very well, but, except when heavy weights are on the hooks, is not likely to supersede the older methods. These links are fitted to machines by makers in Manchester and Bradford. Before the form of griffe shown in Fig. 33 was adopted the hooks were made of two heights, as shown in Fig. 37, and one griffe wrought above the other, instead of the one set of blades or knives passing through each other; but this method was given up on account of the vibration of the long hooks, which made it uncertain whether they would remain on the knives or keep clear of them when required. Fig. 38 is a view of one of the best makes of double-lift jacquards with a single cylinder. The machine is made by Devoge & Co., of Manchester, but is not here given as being specially recommended in preference to others; it is only given as an illustration. Those wanting to buy a machine had better see what are in the market, and select what they consider most suitable to their work and price. This applies to all the machinery given in these articles. There is rarely a best machine for all purposes. These machines are much in use, and can be run at a high speed, say 160, or even 180, and by many are preferred to the double-cylinder machines, as there is no danger of one cylinder getting before the other, and the cards are all laced in one set; besides, it may be more convenient for working, as some arrange their machines so that the cards for one loom hang to the back, and those of the next to the front. When these machines are to work at a high speed, the slide-motion cylinder will probably be found the most satisfactory. Fig. 39 illustrates one of these machines with slide cylinder motion and the The most perfect jacquard machine in the market is undoubtedly the DOUBLE-ACTING JACQUARD WITH TWO CYLINDERSThe only drawback to this machine is, except what may be said against the method of shedding, the liability of one cylinder to be turned out of time, or get a shot or two before the other, so as to put the cards off their proper rotation; but this is only a difficulty in the hands of inexperienced weavers; nevertheless it exists. The effect will be to spoil the pattern on the cloth, giving the twill a mixed or broken-up appearance. There are motions in use for stopping the loom, unless the cards come in rotation, but many prefer to work without them. Fig. 40 is a view of a two-cylinder machine made by Messrs. Devoge & Co., with Fig. 41 shows the arrangement of a row of hooks and needles for a double-cylinder machine. The top needle of the upper set and the bottom needle of the under set are attached to two adjoining hooks, which are connected together with the same tail cord. This arrangement is to enable the cards when working at both sides to act on the correct hooks, which will be better understood by referring to the description of lacing cards for these machines. In Fig. 41 it will be observed that all the hooks are vertical. Sometimes the hooks are slanted a little, as in Fig. 42, to give more space between the hooks at the top, without increasing the width of the machine, and there is a slight difference in the arrangement of the hooks and needles, as is shown. Both work very well. Fig. 43 shows a two-cylinder machine, by Messrs. Devoge & Co., with a slide motion for the cylinders, which would be driven in the same way as the swing motion. It has been said that the shedding of a single-acting jacquard is of the worst description for general weaving. That of the double-acting machine is by no means perfect either; some prefer the single-to the double-acting for making fine damask. Jacquard shedding cannot be regulated in the same way as tappets or the best shedding motions can. In tappets the dwell can be regulated to suit the cloth required, and the time of the shedding can be made early or late as desired. In jacquards this cannot be done to anything like the same extent. The shed must always be open in time for the pick, and the pick should begin when the cranks are about the bottom centre, a little earlier or later, as desired. The jacquard must have the shed open at this time, and must keep it open till the shuttle passes through. It has been said that the usual method of raising the griffe or griffes is by a crank (or a stud in the wheel, which is practically a The smoother and slower the harness can be raised and lowered, the better. Therefore, to get a high working speed, the time or the portion of a revolution of the crank shaft given to the rise and fall must be as great as possible, so that very little could be gained by using a tappet. If a tappet is to be used, a box tappet will be required, or is more satisfactory for a single-acting machine, in order to make the griffe in falling follow the tappet and avoid any plucking or jerking; sometimes a fork lever, with the tappet or wiper working between the prongs of the fork, is used for the same purpose. For a double-acting machine double wiper tappets, acting on levers or treadles, are sometimes used, the griffes falling of their own weight; the tappets are nearly round eccentrics, or like plain tappets with a very short dwell, not more than one-fourth of a revolution of the crank shaft. It may therefore be considered that the harness should always be moving either up or down, with a small pause when the griffes are at the top and bottom, to admit of an easy turn and to allow the shuttle time for its passage through the shed. With the crank drive the shed will require to be opened a little wider than if the dwell was as great as it should be, especially in wide looms, in order to let the shuttle get through freely; but it would be more desirable, and a saving of strain on the yarn, to have the dwell greater, and not open the shed any wider than is necessary to admit the shuttle. Speaking generally, the usual rule for the time of shedding may be said to be to let the shed be closed when the cranks of the loom are at the top centre, or perhaps one-sixteenth of a revolution farther forward, and let the shed be full open when the cranks are about the bottom centre. It therefore follows that the single-acting jacquard must open the shed in a little less than half a revolution of the crank shaft, and close it in the same time; but the double-acting machine takes nearly a full revolution (three-quarters, or a little more, should do) to either rise or let fall one of the griffes. It will be evident that there is a considerable difference in the nature of the shedding. A single-acting machine requires the weft to be beaten up on a closed shed (the time of the crank in coming from the top to the front centre being taken up with rising the griffe from the bottom up to catch the hooks), whereas in a In hand-loom linen damask the shot is struck up when the shed is about half closed; the warp is held so firm in the loom that there is no spring in it, and the weft does not rebound. A cleaner surface is thus made on the cloth than if the weft was struck up in a closed or cross shed. In a single-acting machine the faults in the cloth are more readily seen than with a double-acting one, as, in case of a hook missing the knife, in a single machine it would show in a short time, whereas in The foregoing gives a general description of working the jacquard; but no hard-and-fast lines can be laid down—a little variation may be necessary at any time, to suit circumstances and the class of work. JACQUARD STOP MOTIONWhen working with two cylinders, one may happen to be turned at a time when it should not, and thus put the cards out of rotation. Many attempts have been made to overcome this difficulty by stopping the loom when the cards get out of the proper order, but none of the methods adopted have ever gained much favour. Recently a new motion has been patented, and is being applied to machines by Messrs. Devoge & Co., of Manchester. It is called the ‘Devoge jacquard stop motion.’ Fig. 44 shows how it may be applied to a machine. The hooks A and B and the needles E and F are those here used to work the motion. They may be at either side of the machine, but should be at the side of the belt handle. One hook must belong to the front cylinder needles, and the other to the back ones. The hook A requires a lingo attached to it to draw it down after being lifted. The hook B is attached to a lever connected to the side of the loom, so that when one end is raised a hammer on the other end pushes off the belt Each time the hook A is raised the lever presses forward the needle E, and with it the hook B, which would then be raised by the lower griffe, unless the card pressed the needle back again and pushed it off. Thus, by having a hole cut in the cards for the needle F, and none for the needle E, the hook B would never be raised; but if a hole is cut for E in a card following one in which a hole was cut for F, the hook B would be raised and the loom stopped. It is, therefore, only necessary to arrange the cutting of the cards to allow the loom to work when they are following each other in rotation; but as soon as one card gets out of order the loom should be stopped, though, perhaps, not till it has run for a few shots. Thus—
This gives a repeat of twelve cards; but any number to suit may be used. Thus—
Number of cards— 2,4,6-large dot. 8,10,12,14,16-small dot.
This gives a repeat of sixteen cards. The even numbers of cards go to the front or top cylinder, and the odd numbers to the low cylinder, and it may be seen that a hole in an even-numbered card following one in an odd-numbered card will not stop the loom; but a hole in an odd number following one in an even number will stop the loom, as it is the hook B rising after A that stops it; therefore any suitable rotation of cutting may be adopted, and the stoppage can take place either at short or long intervals, as desired, the principle being to raise the hook A two or three times, and push the hook B back again by having no hole cut for the needle E. Then leave A down for three or four shots, and cut holes for E, which have no effect unless the cards get out of rotation, and one of those with a hole cut to raise the hook A comes before one with a hole cut for the needle E, when B will be raised and the loom stopped. This is a good arrangement, and works very well. Another motion for a similar purpose, invented by the writer, is shown in Fig. 45. It is based on the following principle: Suppose a cord is taken from any two hooks of the jacquard, and passed round a pulley on the ‘hound tail’ or long lever of the weft fork motion; if the cord is left slack, so that raising one of the hooks will just tighten it, then raising both hooks together will lift the lever, and can be made to stop the loom. The difficulty to be got over is that one of the hooks must belong to one griffe, and the other to the other one, in order to make the motion act with the two sets of cards. As the two griffes pass each other at the centre, or at the half-lift, this must be taken as the full lift, the cord must be stopped here, and not drawn any farther; for the remaining portion of the lift the hooks must draw a spring. This can be easily arranged by having loops on the cord passing round wires in the cumber board, or by having the two ends of the cord One of the most desirable arrangements is shown in the figure: A, A are the two hooks; B, B are two small springs by which the two levers, C, C are attached to the hooks with cords; D is the frame for holding the levers, and is fastened to the top rail of the loom, under the jacquard, or in any convenient place. It will be observed that the front bar of the frame passes above the levers, so that it will prevent them rising above the half-draw of the hooks, in which position they are shown. E, E are two cords connected with a jack or tumbler, F, on the end of a bell-crank lever, G H L, having its fulcrum at H, which may be on the same stud as the weft fork lever, or in any convenient place. The weight of F and G keeps the cords in tension, and the point L of the lever is set behind the lever on the loom which carries the weft fork, at such a distance from it that when one of the cords E is drawn it does not act on it; but when both hooks are raised, drawing up the two cords, the point L of the lever presses against the weft fork lever, pushing off the belt handle and stopping the loom. The lever G H L may act directly on the belt handle, if desired; in this case it would be fixed outside the loom framing. The cards are cut on the same principle as for the last motion, but the same holes will do in both sets of cards, as the two needles are acted upon by the same number of holes in both back and front sets; that is, for two hooks coming beside each other. The following order of cutting will answer:—
Cut the large dots on the number of cards given, and of course they must be cut to suit the needles connected with the hooks used. The above gives a continuous working of the motion, but it would be sufficient for it to work at intervals having 8 or 10 shots between them, as—
This will not allow the loom to run for more than 20 shots after the cards get out of order. Some other motions are in use, but these are simpler. Before describing twilling machines or any special make of jacquards, it may perhaps be better to explain the mounting of ordinary machines, according to the usual methods adopted in some of the leading districts. |