Chapter 21

Fig. 167.J.N.

Fig. 168.J.N.

(331) The screw has fixed upon it, at its lower extremity, a small bevel pinion, gearing with a similar one placed loosely on the short shaft forming the centre for the arm. During the oscillation of the arm the pinion moves with it, and it is clear that if both remained in this position only this alternate action would occur, and no rotation of the screw would be made. If, however, the pinion on the short shaft be rotated it communicates its motion to the screwP, and thus traverses the nut. This is what takes place, and the precise method of effecting it will be described in detail at a little later period. The nut engages with the screw and originally had an eye or hook formed in it, to which the end of the winding chain or bandCwas fastened. The attachment is now made in a different manner, a frameAbeing fixed to the nut along with which it can slide. At the upper end of the frame a small drum is carried, round which the winding chain is wrapped, passing over a small bowlDat the lower end of the frame. The other end of the chain or bandCis fastened to the drum or scrollX1which is mounted on a shaftXcarried in suitable bearings in the square. On the same shaft a spur wheel is geared which engages with a pinion loose upon the tin roller shaft, which it revolves by special mechanism afterwards described in detail. The use of a scroll is intended to accelerate the revolutions of the spindles during the latter part of the fallentraverse. This, like the winding arm, is a modified application of the fusee, and it will be easily understood that when the chain is being unwound from the larger diameter of the scroll, the number of revolutions given to the scroll will be less than when it is being taken off the smaller diameter.

(332) It has been previously shown that the diminishing diameter of the spindle causes it to be necessary that, as the cop is built higher upon it, a correspondingly higher rotary velocity shall be given to it, in addition to the increased terminal velocity produced in the manner described. The most usual method of doing this has been to provide at the end of the quadrant arm a bracket carrying a pin known as the “nosing peg.” The object of this device is to shorten the chain by deflecting it from a straight line about the time when the carriage nears the end of its inward run. This is equivalent to a sudden shortening of the chain, and gives a sudden acceleration to the winding drum. In some cases an automatic arrangement is fitted by which the peg is brought into contact with the chain at an earlier point every stretch, so that the acceleration of the spindle takes place sooner, as the nose of the cop is formed higher up the spindle. It is not difficult to obtain a clear notion of the action of the nose peg if a short length of string be held at one end and attached to a sliding piece at the other. If then the string be pressed down by a rod at the same point, but a little further every time, it will be seen that the sliding piece is moved to a greater extent with each depression.

(333) The arrangement used in the Platt mule is shown in detail in Fig.169. It consists of the sliding bracket A, carrying, as described, at its upper part, a small drum on which the winding chainCis fastened. On the spindle of the winding drum a ratchet wheelEis fixed, with which the detent pawlsE1engage, thus ensuring thatEis held in any position assumed by it. Also fastened on the spindle of the drum is the curved sector armF, to which a chainGis secured. By means of the guide pulleys shown the chainGis conducted over the arm or leverK, and is attached to the bracketI. The leverKis hung from its upper end, and has a projecting short armK1attached to it, which can move upwards in the direction of the arrow. The outer end ofK1presses against a bracketK2attached to the quadrant, so shaped that the backward movement of the quadrant pushes the leverKback at its lower end. In the bracketIa fingerI1engaging with the copping nut is fixed. The parts having been adjusted to their proper position the slideAis at the bottom end of the quadrantM, as shown, and the curved armFis in such a position that it has wound upon it a certain length of the chainG. The latter is a little slack at first, but as the nut moves out this is rapidly taken up until the chainGis in tension. As soon as this happens, each of the forward oscillations of the armMleads to the chain being drawn, and causes the lower end of the leverKto be swung forward. The return movement of the quadrant leads to the bracketK2pressing upon the armK1, so as to push back the end of the arm or leverK. In this way the chainGis pulled and the curved armFis drawn a little forward, thus causing the drum and ratchet wheelEto revolve. As the winding chain is wound on the barrel, every rotary movement of the latter in a forward direction takes up a little more chain and shortens its length. The amount of this shortening is not great up to the time of the completion of the cop bottom and the arrival of the slideAat the end of its traverse along the arm. The position ofthe parts at this period is shown in the detached view at the right hand top corner of Fig.169. Up to this time only about the same length of chain is taken up which is needed by the increased distance of the slideAfrom the centre, and the greater forward traverse of the quadrant arm, which, in a sense, releases a certain length of winding chain. When this point is reached the fingerI1begins to be pressed against by the nutS1of the shaper screw, and the bracketIcommences to be drawn inward. To facilitate the correct action of this mechanism the fingerI1is adjustable, and the exact moment of its contact with the nutS1is thus regulated. The forward movement of the shaper nut which follows gives a similar motion to the bracketI, and the chainGis thus drawn forward. In this way the drum and ratchet wheelEare rotated, and the winding chain gradually shortened. Thus more of it is unwound from the scrolls at each traverse of the carriage, and as it is drawn from the smaller diameter of the scroll towards the end of the run in, the velocity of the spindles is considerably accelerated. The position of the various parts when the carriage is at the back stops is shown in Figs.170and171.

(334) These represent respectively the places occupied by the different portions of the mechanism immediately at the completion of the cop bottom, and at the finish of building a set of cops. The positions of the various parts connected with the slideAwhen winding is complete are shown also in Fig.169, at the top end of the quadrant arm. Referring to Fig.170, it will be noticed that the winding chainCis unwound from the large part of the scroll only, while Fig.171shows it almost entirely unwound from the smaller portion. As was shown, this implies a high terminal velocity of the winding scroll and spindles.

(335) It has been previously mentioned that the rotation of the quadrant screw is obtained by means of the engagement of two bevel wheels, one on the foot of the screw and the other upon the spindle, forming the centre of the quadrant. It was also stated that the last-named wheel was held so as to move round the centre with the quadrant. This is effected by means of a brake springP2which clips the boss of the wheel and holds it. The resistance thus created causes the bevel wheel to move with the quadrant, and prevents it from rotating on its axis. The wheel is compounded with a grooved cord pulleyP1, over which an endless bandQpasses. The bandQfits the groove in the pulley, and is afterwards guided by the various carrier pulleys shown. Two of these,S S1, are borne by brackets fixed to the carriage, andSis formed with teeth so as to allow of the engagement of the vertical detent catch on the leverY. If the whole of the pulleys over which the bandQpasses are free to revolve, except that on the quadrant centre, the inward run of the carriage gives no motion to the cord or band. No effect is produced beyond the rotation of the carrier pulleys, and the forward stroke of the quadrant is made without any effect being produced upon the position of the nut.

(336) It was shown that the gradual accretion of yarn by the cop results in the necessity for a graduation of the velocity of the spindle in winding. This takes place during the whole period of building, and it follows that the traverse of the nut must be governed during the whole period. After a layer of yarn has been wound the nut remains in the position occupied by it during the preceding inward run, until the carriage has made another outward run, and is again commencing to run in. At the commencement of the run inof the carriage the spindles revolve at the same speed as that at which they rotated in the preceding period of winding. If the yarn is a coarse one this is sure to be too fast, because of the increase in the diameter of the cop, owing to the yarn wound during the last inward run. The initial velocity of the spindles is, therefore, such that they take up the yarn too rapidly, and put an extra amount of tension upon it. As was shown in paragraph 303, this causes a depression of the counter faller wire. This is utilised to revolve the quadrant screw and traverse the nut and slide. In other words, the winding is said to be “governed,” and the motion is known as the “governing” or “strapping” motion.

Fig. 169.J.N.

(337) Fixed on the winding faller and counter faller shaftsB B1(Fig.168) are two armsU U1, to which the ends of a light chainY1are attached. The chain passes round a runner, or pulley, placed in the outerend of the hinged leverY, which is in this way sustained. It is obvious that the vertical position of the lever will be strictly regulated by the position of the two armsU U1. As they follow the oscillations of the winding and counter faller shafts, the elevated position of these during spinning ensures the leverYbeing raised at its free end. This results in the tooth, or detent, being taken out of contact with the teeth on the pulleyS. When the counter faller is depressed by reason of the tension of the yarn upon it a similar movement occurs in the leverY.

(338) In the early stages of winding, when the winding faller is depressed to a comparatively large extent prior to being locked, the vertical position of the leverYis naturally lower than when the winding faller is not pushed down so far. It thus occurs that, when the cop bottom is being formed, which is the stage during which the traverse of the nut is required, and the winding faller is locked at its lowest point, the clearance of the detent catch onYand the teeth on the pulleySis least. At this period, therefore, they are most easily engaged by any depression of the counter faller. When the higher initial velocity of the spindle, produced as described in paragraph 336, causes the yarn to be put into tension and the counter faller wire depressed, an engagement of the catch and pulley teeth occurs.

Figs. 170 and 171.J.N.

(339) The effect is that the rotation of the toothed pulley is stopped, and the bandQis practically gripped bySand its fellow pulleyS1, which are borne by the carriage. Instead, therefore, of slipping over the pulleys as before, the band is drawn along with the carriage and the remaining pulleys are caused to revolve. The force so applied is sufficient to rotate the grooved pulleyP1by overcoming the resistance of the spring clip, and the bevel wheels and quadrant screw are rotated. The nut is thus moved outwards, and the winding chain relieved as previously described. This causes a slight diminution in the speed of winding, sufficient to relieve the pressure of the threads on the counter faller wire, which rises and breaks the contact of the detent and the toothed pulley. The further movement of the nut is thus arrested.

(340) The necessity for a diminution of the initial velocity of the spindle is strictly relative to the counts of yarn being spun. Some of the finer counts require a very slow traverse of the nut, and there may be practically none during several draws of the carriage. As the nut slowly rises and the locking point of the winding faller is elevated, the period of the engagement of the detent catch and the wheelSbecomesshorter, and the rotation of the screw is not so prolonged. When the cop bottom is fully formed, the nut is at its most outward point, and the “governing” motion is not therefore required. At this point, the relative positions of the armsU U1are such, that the chainY1will not permit the leverYto fall sufficiently to allow its tooth to engage with the wheel. The motion, therefore, falls out of use until the commencement of another set of cops.

(341) The motion of the winding scroll is communicated to the tin roller by means of a catch or “click” plate shown in detail in Fig.168. On the spindle of the winding scrollX1is a spur wheel—indicated by dotted lines—which engages with a small pinion on the tin roller shaftT. The whole of this special mechanism is shown in longitudinal section in the right hand top corner of Fig.168. The pinion is cast in one piece with the discVwhich is loose upon the shaftT. The latter has a pin fixed in it, on which the small catch or “click”V1is hinged. The click catch is ordinarily held out of position by the bent springW1, which surrounds the boss of a ratchet wheelT1—to which the name of the “click wheel” is given. When the “click spring”W1is slightly oscillated in the same direction as the rotation of the ratchet wheel, it allows the click catch to fall into gear with the click wheel. As the latter is keyed upon the tin roller shaftT, the engagement with it of the catch causes the tin roller to be revolved, and thus rotates the spindles.

(342) It was formerly the practice to allow the click catch to fall into gear when the discVbegan to rotate upon the commencement of the inward run of the carriage. It was, however, found that the click catch engaged with the wheel earlier at one stretch than at another, and that, consequently, winding began a little more slowly than it should. The effect of such an occurrence is that a little slack yarn was produced as the carriage was running in, although winding was not taking place. Under these conditions tight winding at the nose throughout was practically impossible. It will be easily understood that, when the click catch is released, it may very readily be left either close to the tooth with which it has to engage or only just over the point of the preceding tooth. In the first case the engagement would take place at once, while in the second instance almost the distance of a tooth would have to be travelled by the click catch before engagement occurred. In hard twisted yarns this is especially objectionable, and its prevention is of importance.

(343) To overcome the defect thus explained a hanging leverWis fitted on the tin roller shaft, and the click springW1, instead of fitting on the boss of the discV, fits on the inner boss of the leverW, which it clips. A slight oscillation of the lever is, therefore, at once followed by the movement of the spring, and the click catch is engaged. The tail end of the leverWcomes in contact with a stopR1on the holding-out catch rodR. WhenRis moved in order to release the catch it causes the leverWto move into the position shown by the dotted lines, and so oscillate the springW1. The tail of the click spring passes between a fork formed in the click catch, and thus presses the catch in either direction, according to which side of the fork it gears with. When, therefore, the click spring is oscillated by the releasing movement of the holding-out rod acting upon the leverW, the click catch is forced hard up to the tooth with which it is engaging. The continued movement of the rod, if made, has, of course, no further effect upon the click catch,but the parts are quite ready for winding with the click in gear. Immediately the carriage begins its inward run winding commences. Thus, whatever may be the position of the click catch at the end of an outward run, it is always ready for its work before the inward run commences. The weight of the rodWis sufficient to keep the click catch disengaged during the whole period of spinning and backing-off.

(344) The whole of the points relating to winding having been considered, the motions used in the fifth and last period require describing. When the carriage is near the completion of its inward run, the various parts are in the following position: The strap is on the loose pulley and the backing-off side shaft is being revolved either by the gearing named, or by its independent band; the back shaft clutch is disengaged and the back shaft is revolving so as to aid in drawing up the carriage; the rollers are disengaged and are not delivering roving; the taking-in friction is engaged, and the scroll bands are drawing in the carriage; the quadrant arm is completing its forward movement, and the spindles are revolving in their normal direction; the winding faller is locked and the wire is approaching the nose of the cop; and the counter faller is in contact with and sustaining the threads. As soon as the carriage arrives at the roller beam, the whole of these motions require changing, so that the different parts shall occupy the positions indicated in paragraph 286.

(345) This operation is mainly the work of the cam shaft, but in part is performed by other mechanism. As soon as the carriage arrives at, or near, the end of its outward run, the hornS1on the carriage comes in contact with the anti-friction bowlR1in the long leverTand depresses it (see Fig.156). This removes the nose of the releasing lever from the raised surface onVand allows the friction clutchW Xto come into gear. The cam shaft immediately begins to rotate, and the three cams to act upon the various parts in the reverse way to that previously described. The rotation of the camZ(Fig.156) performs the two functions of disengaging the taking-in friction clutch and engaging the back shaft clutch, the motions of these always being closely related. The camWduring the same period allows the roller clutch to go into gear, and the delivery of roving again begins. The rotation of the camYcauses it to exercise a thrust on the pin fixed inG(Fig.158), so forcing the driving strap over on to the fast pulley, this giving renewed motion to the spindles. The same movement causes the leverHto be pushed forward until the shoulder formed in it can again engage with the fixed catchL, the springPpulling the end ofHupwards as soon as it is sufficiently far forward. The strap guider is thus again locked when the strap is on the fast pulley. By the time these engagements and disengagements have been made, the cam shaftMhas made its second half revolution, and the end of the release lever again presses upon the raised surface on the camVand detaches the friction coneWfromX. The cam shaft is thus stopped and remains stationary until the end of the outward run as described in paragraph 291.

(346) The whole of the parts governed by the cam shaft having thus resumed their original position, it remains to be shown how the winding and counter fallers are released, so as to be able to assume their relative positions out of contact with the yarn. The unlocking of the winding faller must be made as late as possible in the inward run, but the exact period at which it is made is affected by the height of the cop noseon the spindle. The termination of winding requires to be made throughout the whole period of building a set of cops, at such a point as to leave sufficient yarn to coil on the spindles between their points and the cop nose. It will be easily seen that this quantity is varying throughout the whole of the formation of the cop, and that the length to be wound on is greatest at the commencement of the cop. This implies the unlocking of the winding faller at a point which is made gradually later, and this is well carried out in the Platt mule. At the lower end of the locking lever is a curved arm or “boot leg,” which, at the termination of the inward run, comes in contact with the fixed stop bracketG(Fig.161). The face of this is so shaped that the moment of unlocking is regulated in accordance with the requirements of the case throughout the whole of the formation of the cop. This is an important point, and requires careful attention. In a special form of mule, made by Messrs. Platt Brothers and Co., for finer counts, the stop bracket is a movable one, and is released by the run of the carriage, so as to slide forward and unlock at the exact moment required. The finer the yarns the more care is required in this respect, owing to their greater liability to breakage.

(347) Referring now to the release of the winding and counter fallers, it is essential that they should leave the yarn free as soon as spinning begins. For this purpose the leverJis raised by contact with the small rollerW(Fig.159), and its weight is removed from the counter faller shaft, and also from the winding faller. Still further to facilitate the descent of the counter faller, which is sometimes a little sluggish, a stop is placed in the headstock, which engages with a tail piece on the counter faller shaft when the carriage has run in. This arrangement is shown in the dotted lines at the right hand top corner of Fig.161. The weight of the winding faller connections is, of course, sufficient to lift it quickly out of contact with the yarn.

(348) The operations thus described constitute the fifth period, and at its termination the mechanism is again engaged in the work of spinning or twisting, being at the commencement of another cycle of movements. There is, however, one more piece of mechanism to refer to before the description of this machine can be brought to a close. It was seen that during the period of winding the chain was drawn off the winding scroll during the forward stroke of the quadrant arm. Referring to Fig.172, which represents a portion of the mechanism relating to the quadrant, it will be seen by the arrows that during the outward run of the carriage, the quadrantMalso makes its backward stroke. During the same period it is necessary to rewind on the winding scroll the chainCwhich was previously unwound, and this is effected by the cordS.Sis attached at one end to a hook or stapleT, fixed to the framing, and at its other end to a weighted leverU, pivoted on a bracket fixed to the floor. The cordS, in its course, passes over the two pulleys shown fixed to the carriage, and its tension is sufficient to cause the pulley on the shaftXto be rotated by the inward run of the carriage, thus winding the chainCon to the scroll. By the termination of the outward run this operation is concluded, and the chain is ready to act again efficiently as soon as winding recommences. When a “set” of cops—that is, the whole number spun on a mule—is finished, it is “doffed” or stripped from the spindles. As soon as this is completed the winding nut is wound back by hand to the bottom of the quadrant, and the copping plates are also restored manually to their original position.

(349) The description thus given of the machine as made by Messrs. Platt will enable an accurate idea to be obtained of the mechanical movements which are found in the work of a mule. It is true that this special machine differs in some of its details from many of other makers, and that there are motions fitted to it which are not found in other machines. When the latter are used, however, they tend to increase the automaticity of the machine. The winding chain shortening, or, as it is more correctly called, the nosing motion, and the backing-off chain tightening motion, are of this class, both tending to an increased efficiency. The main principles in a machine of this class are embodied in the mule described, and the general explanations given will prove serviceable, whatever may be the make of mule studied.

Fig. 173.J.N.

(350) One of the important points of difference between this and mules of other makes is found in the position of the cam shaft. This, it was seen, is in the Platt machine placed above the axis of the rim shaft. In other cases it is placed, as shown diagramatically in Fig.173, along the headstock of the mule, and below the centre of the long or “balanced” leverT. In this case the cam shaftKis a tubular one, and has passed through its centre the shaftM, which is suitably driven from one end. The cam shaft is fitted with a friction clutch atP, the fixed half being on the tubular shaft. The other half slides on the shaftM, being pressed up to the fixed half by the spiral spring shown. On the long leverTat the pointLa pendant cam plate is hung, which surrounds the cam shaft as shown in a detached front view and section in Figs.174and175, and is formed with a slot so as to permit it to rise and fall freely. The cam plate has two raised cam surfaces or courses, against which the end of a pin is pressed by the action of the spiral spring. The pin passes through the half clutch fixed on the cam shaft, and presses against the sliding half on the shaftM. Thus when the pin is on the raised part of the cam plate the clutch is detached, while if it is on the lower part the clutch is in gear. When, therefore, the inner end of the balanced leverTis depressed, the fall of the pendant plate causes the pin to come upon the lower part of the cam course, and permits the engagement of the clutch. The cam shaft thus makes a half circle turn, and effects the necessary changes for beginning spinning. This causes the end of the pin to run on to the second cam course, and by the time the half revolution is made,it comes on the raised surface and disengages the cam. In this position it rests until the outer end of the long lever is depressed, when a similar action occurs, terminating in a similar way.

Fig. 172.J.N.

(351) The back shaft is also engaged and detached in a different manner. It is driven from the roller shaft by a train of wheels, but the last of the train is a compound one, consisting of a large wheel with a smaller pinion. The latter gears with the back shaft wheel, and is put into or out of gear accordingly, as it is desired to revolve or stop the rotation of the back shaft. For this purpose the compound wheel is borne on a hinged lever, called commonly the Mendoza lever, which is weighted in a suitable manner. The exact origin of the word Mendoza, as applied to this lever, is difficult to define, but it probably arises from the French phrase,main douce—Anglicè, the soft hand. However this may be, the function of the lever is to put the pinion into and out of gear with the backing-off wheel, and to effect this, its motion is controlled by a cam or eccentric on the cam shaft. This cam works in a fork in a lever, and the rotation of the cam shaft raises or lowers the Mendoza. The object of the weight is to ensure the full engagement of the pinion and back shaft wheel, so as to obviate any jumping out of gear at the commencement of winding. There is some tendency towards this unsteadiness of driving in the early part of the outward run, and it is desirable to lock the Mendoza lever in position.

Figs. 174 and 175.J.N.

Fig. 176.

(352) Messrs. John Hetherington and Sons employ a special device by which this difficulty is overcome. The mule, as made by them—arranged to be driven with the rim shaft transversely, instead of longitudinally, placed in the headstock—is illustrated in Fig.176in longitudinal elevation, and in Fig.177in back view. Both views show the method of driving quite clearly. On the outward end of the Mendoza weight a pin is fixed which takes into a fork formed at the upper end of a vertical lever. The fork is shaped with a shoulder or recess, below which the pin referred to can slip when desired to lock the Mendoza in position. A small ear is formed on the vertical lever, through which a set screw is passed, the point of which comes in contact with the end of a horizontal lever centred on a pin fixed in the headstock. The last named lever has a long tail extending outwards toward the carriage. When the carriage comes up to the back stops and the Mendoza lever falls, putting the driving pinion into gear with the back shaft wheel, the long tail of the horizontal lever is raised, and the effect is that the pin in the Mendoza weight passes under the shoulder of the fork in the vertical catch lever, and so firmly holds the Mendoza lever down. As the latter carries the driving wheel, the pinion is kept firmly in gear, and the effective driving of the carriage is obtained. As soon as the carriage has run out a little—by which time it has gained momentum—the horizontal lever is released, andits long end falls, thus freeing the catch or pin in the Mendoza. Sometimes the minder, in cleaning, runs out the carriage a little and then changes the cam, without freeing the horizontal or locking lever. If afterwards the mule is started the carriage endeavours to run in, although the back shaft wheel and its driving pinion are in gear. This leads to breakages, and in order to avoid these, Messrs. Hetherington have arranged a small relieving lever, coupled to the long lever, so that any motion of the latter causes the relieving lever to act and free the Mendoza catch pin, without reference to the position of the horizontal locking lever. This mule is arranged with the extra band for driving the taking-in side shaftDreferred to in paragraph 286. The bandEis driven from the counter shaftR, and passes round a double grooved pulley onD. It is kept in tension by the pulleyF, carried by a frame which can be moved inwards by the quadrant rackGwith which a worm gears. The remaining reference letters indicate the same parts as in the other illustrations.

Fig. 177.

Fig. 178.

(353) It was shown that to perfect the action of winding at the nose of the cop it is customary to deflect the chain by means of a nose peg. A motion based upon the principle of the deflection of the chain, but in which that object is attained in a different fashion, is shown in Fig.178in side elevation, and inFig.179in enlarged detail. This is Dobson and Hardman’s patent, and is made by Messrs. Dobson and Barlow. Two main objects have been aimed at. These are the control of the winding from the faller—so that the relation of the two will be strictly maintained—and the deflection of the chain by a pull from below instead of a push from above. On the faller shaft a tappet is fixed, to which is jointed a leverJwith an arm or fingerKsecured to it. A bracketHis attached to the quadrant arm a few inches from its centre, and its outer edgeH1is formed into a rack with which two catches engage. These are carried by a leverG, which is hung on a pin in the upper part of the bracketH.Ghas a projecting shoulder at its outer end, to which is fastened one end of the chainEpassing over the pulleyF, and having its other end attached to the lower end of the linkC. The winding chainBis also attached to the linkC. The leverGis formed with an armG1, to which is jointed a double tumblerI, each part of which is free to move as required. A projection is cast onI, which causes it to rest onGwhen in its normal position. This mechanism acts in the following manner: When a set of cops is begun the leverGis at its lowest position relatively to the quadrant rackH1, and the winding chainBand linkCare then almost straight. At the end of each stretch the fingerKcomes into contact with the lower part ofI, which is raised to allowKto pass. When the inward run beginsKcauses the projection onIto press upon the leverGand raise it if the pressure is maintained a sufficient time. Whether this is so or not is determined solely by the vertical position ofJ, which, in turn, is regulated from the winding faller. If the latter is not substantially raised from stretch to stretch the position ofGin like manner remains unaltered. If this is not the caseGis a little lifted, and the chainEis thus drawn forward a little over the pulleyF. The result is that a pull is exercised on the linkC, which is drawn down so that it and the chainBno longer represent a straight line. This is equivalent to shortening the chainB, and the result is that the necessary acceleration of the windingdrum is effected. The chief feature of this motion is the regulation which is obtained from the faller, the position of which fixes the amount of extrapullput on the drum. However slowly the building proceeds the necessary acceleration is made in exact proportion.

Fig. 179.J.N.

(354) In the description of the governing motion, given in paragraph 339, it was shown that the rotation of the screw in the quadrant arm is made during the inward run of the carriage. There are some objections made to this procedure on the ground of the extra tension put on the yarn in the early part of winding, which is of some moment when fine or tender yarns are being spun. In Fig.180a side view is given of a motion made by Messrs. Dobson and Barlow, which is designed to obviate the necessity for altering the screw during the inward run, and provide means by which it can be made during the outward run. In lieu of the ordinary grooved pulley on the quadrant axis, a toothed wheelUis used, with which a toothed rackRcan engage under circumstances presently to be described. The rackRis carried by a sliding frameS, which is fixed upon a longitudinal rodT, extending backwards in the headstock, and carried by brackets fastened to the floor. The rack is fitted at one end with an inclined foot, and at the other with a spring, which prevents too deep an engagement of the rack and wheel. The rack passes—during its outward stroke—over a frame fastened to the headstock, in which is a screwXon which is threaded the sliding stopW. The pitch of the screw thread is varied to correspond with the thread in the quadrant armQ, and the screw is rotated by a ratchet wheel, with which a pawl, oscillated by a finger, engages. At the pointIa loose tongue is hinged, which at the end of the stroke of the frame engages with the nutW. On the winding fallera sectorYis fixed, in which a stud, formed with two portions of different diameters, is bolted. On the counter faller a sectorZis fastened, carrying a screwed staple, to which is secured one end of a chain, indicated by dotted lines. The chain passes round the bowlRat the upper end of the pendant leverO, guided in brackets at the front of the carriage. The loose end of the chain is formed into a loop, which can be slipped on to either of the surfaces of the bowl in the sectorY. A hinged fingerLis carried by a bracket on the rodT, and has a little range of movement in a circular direction.

(355) In beginning a set of cops the stopWis turned back to its proper position, which is determined by the size of the cop about to be spun. The frameSis then pushed forward as much as possible, and the chain is slipped on to the smaller portion of the bowl inY. This allows the pendantOto fall a little, and its height subsequently is regulated strictly by the position of the fallers. During the outward run the horizontal armP, which forms part of the pendantO, engages with the vertical projection on the frameSand causes it to move forward. The rackRbeing raised engages with the wheelUand rotates it, this movement being consequently communicated to the quadrant nut. Thus the latter is put into position for action during the next period of winding and any straining of the yarn is avoided. As the stroke of the rack is continued, the tongueIengages with the nut and causes the rack to drop out of gear with the pinion, and any further movement of the quadrant nut is avoided. It has been shown that the traverse of the latter is gradually diminished as the cop is built, and, in like manner, the inward motion of the stopWcauses the engagement of the rack and pinion to be limited. This is a sort of “trip” motion very familiar to students of steam engine practice, and is well applied in this case. The slideSis drawn back into position by the engagement of the lower end of the pendantOwith the fingerL. A slight contact at first between these becomes a firm one by the backward movement of the finger when pressed upon by the pendantO, but it will be obvious that, if the latter is too high to move the fingerL, the rack will remain untraversed until a sufficient depression ofOtakes place. It only remains to be said that once the nutWhas been set at the beginning of winding, all that is required is for the minder to slip the loop of the chain on the right portion of the bowl inY, and the motion acts automatically until winding is finished.

(356) A somewhat similar attachment has been recently introduced in France, and is the invention of Mons. Dubs. The author is informed by a trustworthy mechanician that the motion acts perfectly throughout winding, and it may, therefore, be well to give a brief description of it. As in the motion of Messrs. Dobson and Barlow, the regulation of the nut takes place during the outward run, and it is unnecessary to again detail the reasons for this course. The chief operating part of the mechanism is the rack fingerA—shown in its position when in gear—which is hinged on a vertical rod or plungerK, sustained in a frame or bearingSfastened to the carriage. Referring to Fig.181, the whole of the apparatus moves with the carriage and is self-contained. Attached to the faller is a connecting rod or linkB, which is coupled to a hinged leverOformed at its outer end with a toothed rack or quadrant finely pitched. With this rack, which has two sets of stepped teeth, two detent catchesHengage. The leverOis hinged to a plungerL, which has at its lower end a screwed shank fixed to a plateFalso secured in the same manner to theplungerK. The inner end of the rack leverAhas a hanging pieceDwhich can engage with a catchEon the plateF, but which in the view is shown out of gear. The downward motion of the inner end ofAis regulated by the stop screwR, and it is coupled by the chainCto the counter faller. The springMconstantly presses the inner end ofAdown, tending to raise the rack. When the various parts are adjusted the partsF KandLmove together and simultaneously with the leverO.

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