WHERE more than one kind or colour of weft is used in a fabric, it is, of course, necessary to change the shuttles automatically. Sometimes two or more different counts of weft of the same colour are used, and sometimes different colours of weft. Checks of all kinds, extra weft spots, and others are the chief classes of fabrics which require change boxes.

The oldest and commonest form is the Diggle’s chain motion illustrated at Fig. 76. The number of boxes used in this motion is either 2, 3, or 4. It would be possible to use more, but it is not usually done with this arrangement for operating them. A lever, AC, is centred at C (Fig. 76), and the friction bowl B on this lever is moved upwards by a chain, composed of links fastened together on pins, which work round a barrel, D. These links are of different sizes, according to the number of boxes used. The smallest link leaves the top box in a line with the shuttle-race, and the other links are of such a size as to raise either the second, third, or fourth boxes (assuming that there are four) into this position. The general method is to raise the boxes one at a time, and drop them all together, but this is not compulsory. It will be seen that the motion of the boxes is not positive downwards—that is, the boxes drop by their own weight, and are not mechanically forced down, as in Wright Shaw’s or Whitesmith’s motions—and it will be well understood that there will thus be a limit to the speed at which the loom can be run. The method of turning the barrel D which carries the chain is as follows. A wheel, E, on the crank-shaft drives a larger wheel, F, above it. On the face of this wheel, F, is a rim and two projections, PP, or, it may be, only one projection. These projections or pins gear into the star wheel G, which is fastened to the barrel carrying the chain, and therefore when the star wheel is turned one tooth, or one-eighth of a revolution, it will move the chain a space of one link. The wheel E on the crank-shaft often has one-fourth the number of teeth contained in the wheel F; therefore, if there are two pins or projections, PP, in the circumference, the star wheel will be moved one tooth every two picks, and the boxes may be changed so often by making the chain accordingly. The lever M, which is centred at R, has the boxes attached to one end, and the other end may be pressed down by the foot when it is required to lift the boxes for any purpose when the loom is stopped. Supposing the wheel E to have 15 teeth and F 60 teeth, if there are two projections, PP, on the face of F, the shuttle may be changed every two picks, but if there is only one projection or pin, there may be a change every four, or a multiple of four picks.

The chief disadvantage of this motion in the form given at Fig. 76 is that the chain becomes very cumbersome if a long pattern is required. To obviate this, the projections PP are, in an improved motion, made so that they can be withdrawn from gear with the star wheel. This is effected by a clutch motion which is subsequently described in connection with the “pick-and-pick loom.” With this improvement, each link in the chain may be made to represent any number of picks, the number being regulated by a small chain of metal cards, and thus larger patterns may be made without the long heavy chains which are required in the ordinary “Diggle.”

The Diggle’s chain principle, although suitable for some types of looms, is not an ideal motion, as the downward movement of the boxes is negative. The boxes have nothing to force them down but their own weight and the weight of the levers connected with them, and this necessitates the loom being run at a slower speed than is the case with some of the positive drop-box motions. Of this latter kind Wright Shaw’s motion is one of a great variety of different types, and has been in use for a long time.

The principle of this motion will be understood from the diagram, Fig. 77. The essential feature of this invention is a forked rack, G, suspended from the free end of a treadle lever, E, fulcrumed at F, and carrying a bowl or runner, D, near the centre. At one end of the second motion or picking shaft, A, of the loom, are two cams, B and C, either of which may be brought underneath the treadle bowl at will, so as to raise the treadle and forked rack once during each revolution of the picking shaft, corresponding to two picks. Passing midway between the two prongs, H, H', of the fork is a short shaft, upon which are secured two toothed wheels, I and J. Wheel I is so placed that the teeth on either side of the rack may be put into engagement with its teeth just before the fork rises, so as to turn the wheel in either direction; or the rack may occupy a neutral position when rising, in which event the wheel remains stationary. In any case, the racks are always clear of the wheel when descending. Immediately in front of wheel I is another similar wheel J, whose teeth are in permanent engagement with those of a rack, K (an extension, L, of which supports the shuttle-boxes, M). Thus, if rack H' is put into gear with wheel I, boxes will be depressed as the rack rises; but if rack H operates, the boxes will be raised. One box, or two boxes, only, may be either raised or dropped at one change, according to which rack and which cam is put into operation. The smaller cam moves one box, and the larger cam two boxes, either up or down.

The selection of racks and cams is made by pattern cards (detached) which pass over an octagonal prism, N. The cards are presented separately, once in two picks, to three selecting needles, 1, 2, 3. The two outer needles, 1, 3, are attached one at each end of a double arm secured at the top of a long vertical shaft, O, the bottom of which communicates with the forked rack G. Thus a depression of boxes is effected by a blank part of a card pressing against needle 1, and an elevation of boxes by pressing back needle 3. Shaft O is loosely contained within a long tube or sleeve, P, which carries a short arm, R, at the top, and a forked clutch, Q, which acts upon the boss of cams, B and C. If it is desired to move two boxes, needle 2 is pressed back, thereby causing an inclined piece, S, secured to it, to act upon arm R so as to slightly turn the sleeve P, and move the larger cam C under the treadle bowl at a time when the short side of the cam is uppermost, as indicated in the diagram, Fig. 77. At one point, the larger and outer cam is slightly lower than the smaller one, and can be readily moved under the bowl.

The various changes which can be made by this motion may be seen by referring to the cards at Fig. 77. When there is a blank opposite the first needle only, the rack H' is pushed to the left and the boxes are moved “down one.” When there is a blank opposite the third needle only, rack H is moved to the right and the boxes are forced “up one.” When there are blanks opposite the first and second needles, they are pushed backward, thus moving rack H' to the left, and also forcing the larger cam under the treadle bowl, in which case the boxes will be moved “down two.” When there are blanks opposite the second and third needles, they are pushed backward, and the boxes are “raised two.” When there are three holes in the card, the racks, when lifted, miss the wheel, and there is “no change” in the boxes. It will be seen that the boxes may be moved either up or down, a space of one or two boxes only at a time. There may be more than three boxes, as many as five being regularly used; but if there were five, it would not be possible to change from the first box to the fourth or fifth. The greatest change which can be made is from the first to the third, fourth to second, and so on.

The principle of Whitesmith’s motion is probably the best for any number of boxes. It is usually made for four, and the change may be made with certainty from one box to any other. The arrangement for working four boxes in a loom is illustrated at Figs. 78, 79, 80. The principle will be best understood by referring first to Fig. 80. The four different positions of the boxes are here shown. The boxes are connected to the ring or strap of an eccentric at the point E, and at A the position of the parts is shown when the boxes are at their lowest point. The eccentric, F, on the shaft has a lift of one box, and therefore by causing it to make half a revolution intermittently every two picks, the boxes would be alternately lifted and dropped a space of one box, as will be seen by referring to C (Fig. 80), where it has made half a revolution from its position at A. It will be seen that E is one box higher at C than at A. Starting again from the first position, as at A, by turning the outer ring halfway round and leaving the eccentric stationary, there will be a lift of two boxes. This is shown at B (Fig. 80). Again starting with the first position, as at A, if we turn the outer ring halfway round, and at the same time turn the eccentric F half-round, we lift a space of three boxes—that is, from the first to the fourth box. The position of E in this case is shown at D (Fig. 80). We thus see how from the bottom box any other of the four can be reached. By turning the eccentric halfway we lift one box, by turning the ring halfway round we lift two boxes, and by turning both ring and eccentric halfway round we lift three boxes. If we are at the third box, as at B (Fig. 80), and we wish to reach the second box or one lower, by turning the eccentric half a revolution and the ring half a revolution we shall get the position required. It will thus be seen that any one of the four boxes may be reached at will. At Fig. 79 another view of the eccentrics and boxes is given. The wheel H is keyed to the shaft on which the eccentric is fixed, and riding loosely upon this shaft is another wheel, I, of the same size, to which a fork, K, is attached. This fork fits on to a pin at the back of the ring, and thus by turning the wheel I the ring can be moved independently of the eccentric. If the wheel H is moved it moves the cam, and if the wheel I is moved it moves the ring. Referring now to Fig. 78, the wheel H is shown. This wheel is driven by a wheel, I (Fig. 79), twice its size. On the face of the wheel L there are four pins, and by lifting the lever OP at O, the pulling hook M is dropped round one of the pins, and the hook being moved forward by the crank Q will cause the wheel L to make a quarter of a revolution and the wheel H to make half a revolution, and therefore the eccentric is moved half a revolution. On the same stud as the wheel L there is another wheel exactly the same size and with four pins; this wheel (which cannot well be shown in the diagram) gears into the wheel I shown in Fig. 79. There is also another pulling hook which works along with M. This second pulling hook is operated by another lever like OP. There are two levers, X, which are lifted by the cards, and by lifting X, either, or both, of the pulling hooks may be dropped, and either of the wheels I or H (Fig. 79) turned half a revolution, but always in the same direction.

The wheel L and its companion are prevented from turning too far by a strong friction arrangement.

This motion may be adapted to work six boxes, or even more. For six boxes there is another eccentric inside the first eccentric, which can be worked independently; this will, of course, require a third pulling hook, and so on.

Many loom-makers have patented arrangements on the same principle, which do away with the pulling hooks M, and it is probably in this direction that the motion may be improved.

The Whitesmith principle is simple, and positive throughout, and it is difficult to see why it is not in more general use. It is generally admitted by those who have had practical experience of drop-box looms on this principle that it is the best. There are other drop-box motions, but the foregoing are the chief kinds.

These are not used in the cotton trade to anything like the extent they are in the woollen and worsted trades, especially in Yorkshire. It is remarkable that this should be the case, as it is claimed for circular boxes that they can be run at a higher speed than any other kind. Circular boxes are usually made for six shuttles, generally to move only one box at a time, but they are made to skip one box, although the arrangement is by no means so simple or satisfactory as in a well-made loom on Whitesmith’s principle, where the changes are made from one box to another almost noiselessly. At Fig. 81 the mechanism of a circular-box motion is shown. There are two hooks, A and B, which act upon pins outside the boxes. When the hook A is pulled down the boxes will be turned one to the right, and when B is pulled down they are turned one to the left. A lever, EF, is connected with the lower part of each hook, and another lever, M, is lifted every two picks by means of a cam, C. The cards lift or drop the L lever QS at S, and so the hook H can either be lifted or left down by the lifter M, and the boxes can be turned one in either direction. A disadvantage of circular boxes is that they cannot be used in fast-reed looms on account of the difficulty of operating the stop rod from the back of the boxes. They are therefore only used for weaving the lighter classes of fabrics.

The majority of box looms are made with movable boxes at one side of the loom only, so that single picks of any colour cannot be put in the cloth at will. As it is very desirable in many fabrics to use single picks of a colour or count of weft, it is necessary to have movable boxes at both sides of the loom, and where this is the case it is usual to have picking mechanism which will allow of several picks being made in succession from either side of the loom. If the matter be carefully thought over, it will be easily apparent that even with drop boxes worked quite independently of each other at both sides of the loom, if the picking mechanism is of the ordinary kind—viz. to pick once from each side alternately—it would be impossible to obtain that variety of changes in the shuttles which is in many cases necessary. In a loom with two boxes at each side worked independently, it would be impossible to obtain single picks alternately of two colours or counts. But by being able to pick twice in succession from each side this can be done. By going through all the changes possible with a given number of boxes, the advantage of this kind of picking arrangement will be very apparent, in the command it gives over any shuttle in the series for any pick. It is therefore necessary to have the picking mechanism aforementioned in order to allow of all the boxes being emptied at one side if required. A loom of this character is called a “pick-and-pick” loom; the picking motion is sometimes called a “pick at will” motion. The loom which we take as an example is one on the Diggle’s chain principle. There are two chains, placed at one side of the loom for convenience. Both chains are on one barrel, A (Fig. 82). The chain for working the boxes at the right-hand side of the loom operates the lever B, and the left-hand chain operates the lever C, the fulcrum of both levers being at D. When these levers are lifted they lift the levers E and F, and when E is lifted it lifts the boxes at the right-hand of the loom, and when F is lifted it lifts the left-hand boxes. The connection of the left-hand boxes with the lever F is shown at Fig. 83. The shaft G is placed under the loom, and the left-hand boxes are connected to the lever H, which is fast to the shaft G. The lever F is also fast to the shaft G, but the lever E rides loosely upon this shaft, which merely serves as a fulcrum for E. From these two figures it will be clearly understood how the boxes may be worked independently at both sides of the loom by two chains placed side by side upon the barrel A.

In order to make each link in these chains represent any number of picks, and thus prevent long cumbersome chains, the mechanism shown at Figs. 84 to 87 is employed. The barrel A in Fig. 84 is the same as barrel A in Fig. 82, and carries the chains for lifting the levers B and C. At the end of the barrel the star wheel I is fixed, and this star wheel is turned by the pins J. These pins are worked by a clutch motion shown at Fig. 86, by which they can be withdrawn from gear with the star wheel as desired. The pins KK are fixed, and turn one tooth of the star wheel Y every pick, the wheel M having twice the number of teeth contained in L, which is on the crank shaft of the loom. The star wheel Y is fast to the end of a small octagonal barrel, which carries a pattern chain N composed of small metal cards, and we have seen how this barrel is turned one division every pick. Above this pattern chain N a finger, O (Fig. 86), is placed, and is lifted up against a spring every pick by the cam P on the face of the wheel M. When the finger is up, the pins JJ are taken inside the wheel M, as shown at Fig. 86. The cam P only raises the finger a sufficient length of time to allow the barrel Y to be turned round, and if there is a blank in the cards opposite the finger O when it is let down by the cam it will still keep the pins J inside the wheel, and will thus prevent either of them from engaging with the star wheel I, and will leave the boxes unchanged. This can be repeated any number of picks. If a change is required in the boxes, a hole is placed opposite the finger O, and when it is let down the pins J project through the wheel M (as indicated by the dotted lines in Fig. 86), and the star wheel I will thus be turned one tooth, and the chain can make the change required in the boxes.

Fig. 87 is another view of the cam-shaped projection P, which raises the finger every pick, and Fig. 85 is another view of the chain barrel A. The letters in the six Figs. 82 to 87 inclusive refer to the same parts in each case.

In this way the chains on A are rarely required to be very long, as one link may be made to represent any number of picks from one upwards. Of course a separate card on Y is required for each pick, but these are very small, only about 1½ inch in length, and a large pattern can be made with very little trouble.

When a Jacquard is used on one of these looms it is sometimes necessary to work the pattern from the Jacquard cards. This can be done in a very simple manner by covering the hole in the barrel carrying the cards N with a metal plate, which is held over the hole by a spring. When a change is required in the boxes, a Jacquard hook pulls the plate from over the hole, and allows the finger O to drop, and thus causes the star wheel I to be engaged by the pins J.

The picking mechanism in a pick-and-pick loom may be either over or under pick. In the former the picking tappets are sometimes moved on the shaft by a clutch arrangement. In the latter the top of the picking treadle is movable. As the under pick is perhaps the best adapted for this loom, we will describe it.

Fig. 88 is a side view of the loom, and the top of the picking treadles consists of a metal plate with the “shoe” S of such a shape as to give the required force and character to the pick. This metal plate works round a pivot, P. The treadles at both sides of the loom are the same in this respect. At the back of the loom a rod, R, is connected to the extreme ends of the loose plates or the treadles, and when one plate is on the treadle, the other is fixed off its treadle, as shown in Fig. 89. The consequence is that when the picking bowls come round (there are two bowls on the bottom shaft at each side of the loom) the loom will pick always from that side where the loose plate is on the treadle, and at the other side, where the plate is off, the bowls will pass over the treadle without touching it. By moving the rod R sideways, the plates may be moved alternately off and on their treadles.

If the loom has four boxes at each side, it may be necessary to pick four times in succession from one side of the loom, and by a simple arrangement the picking can be regulated at will. The mechanism for moving the rod R sideways is shown at Fig. 90. Inside the loom framework a lever, L, is centred at C, and by a combination of levers is connected to the rod R, which is the rod referred to in the previous diagrams. A strong spring keeps the plates right for picking from one side, but when it is required to pick from the other the lever L is lifted, which moves the rod R sideways and moves the plate off one treadle and on the other. A chain is used for lifting the lever L, and the star wheel A is turned by two pins on the wheel B on the bottom shaft of the loom, or by one pin if on the crank shaft, thus causing the star wheel to be turned one division every pick. The loom may thus be made to pick four times from the right side, three from the left, twice from the right, and so on, of course always taking care that the shuttles are there to be picked.