US2827244A

US2827244A - Winding machine and method

Info

Publication number: US2827244A
Application number: US578605A
Authority: US
Inventors: Winthrop L Perry
Original assignee: Abbott Machine Co Inc
Current assignee: Abbott Machine Co Inc
Priority date: 1956-04-17
Filing date: 1956-04-17
Publication date: 1958-03-18
Anticipated expiration: 1975-03-18
Also published as: FR1173423A

Description

March 18, 1958 w. 1.. PERRY 2,827,244

WINDING MACHINE AND METHOD Filed April 1'7, 1956 5 Sheets-Sheet 1 March 18, 1958 w, PERRY 2,827,244

WINDING MACHINE AND METHOD Filed April 17, 1956 3 Sheets-Sheet 2 I J60 Zja/ CL arc/v March 18, 1958 w. L. PERRY WINDING MACHINE AND METHOD 3 Sheets-Sheet 3 Filed April 17, 1956 United States atent fihce 2,827,244 Patented Mar. 18, 1958 WINDING MACHKNE AND METHOD Winthrop L. Perry, Milford, N. H., assignor to Abbott Machine (10., 156., Wilton, N. H., a corporation of New Hampshire Application April 17, 1956, Serial No. 578,605

13 Claims. (Cl. 242-427) particularly at its base end, in a more reliable manner than is accomplished in conventional machines, and by improved accuracy of centering to permit increase in speed of rotation without undue vibration.

For a considerable time, manually tended Winders for loom bobbins were provided with driven spindles extending through the bobbin, the bobbin fitting frictionally on the spindle and being driven thereby. In automatic loom bobbin winders, wherein the bobbins are placed in Winding position and removed from winding position automatically, the winding bobbin is generally held by a pair of opposed holders such as chucks. These holders press'the bobbin axially between them, and one or the other holder is movable to release the bobbin from winding position, the bobbin usually being allowed to fall by gravity.

With this general construction of automatic machine there is no absolute need for the bobbin to have a central bore extending through it, although such bobbins having central bores have continued to be used. For such bobbins, having a bore, or at least a hole in the base end, one method of centering the bobbin is to employ a conical interior center, extending into this bore or hole. However, inaccuracy of the bore or hole, or injury or distortion of the base end portion of the bobbin will prevent accurate centering. Also it is customary in automatic loom bobbin winders to clamp the thread at the base chuck. Such a conical interior center does not afford a suitable surface against which the thread can be reliably clamped by the bobbin, so that with such a conical interior center some additional means must be provided for clamping the thread.

Moreover, interior centering, by a tapered center wedging into a hole in the bobbin, necessarily exerts an outward component of force tending to split the bobbin.

It is well known to employ a cup-like chuck having a flaring entrance intended to center the base end of the bobbin.

Such a cup-like chuck may be designed so that the end face of the bobbin seats against a friction drive surface forming the base of the cup. In this case it will be seen that uniform accuracy of centering would not be obtainable unless the bobbins had a very uniform contour and unless the chuck accurately fitted the particular bobbins employed. In other words, without this uniformity of bobbins and accuracy of fit, which are difiicult to obtain in practice, then in order for the base ends of the bobbins to seat with certainty against the drive surface, there would necessarily be in most cases some looseness of the bobbin in the flaring cup.

Attempts to secure accuracy of fit between the chuck and the bobbin base involve the further difliculty that the many diiferent manufacturers of bobbins give slightly different contours to the endmost base portions of their bobbins.

It might be supposed that these difficulties could be avoided by lining a flared cup-like chuck with a resilient material frictionally engageable with the rounded end shoulder portion where the peripheral surface of the bobbin merges into the end face of the bobbin, thus causing the contour of the bobbin and fit of the chuck to be less critical. However this arrangement fails to take into account the fact that this end portion of a bobbin is subject to distortion as it ages and is subject to injury in the loom. Such distortion and injury can prevent the bobbin from being centered accurately enough to run at high speed in the winder, even though the distortion or injury is not sufficient to impair the usefulness of the bobbin in the loom.

The present invention involves the thought that the rings with which automatic loom bobbins are customarily provided, for positioning the bobbins in the shuttles, constitute the most uniform and the most permanently accurate parts of loom bobbins, and that the chuck for the base of the bobbin should exert its final centering action altogether through such a ring. By this means, the bobbin can be centered in the automatic winder with greater accuracy than is obtainable with previous methods of centering, and notwithstanding inaccuracy, injury or distortion of the endmost part of the body of the bobbin.

Preferably, in carrying the invention. into practice, the chuck which receives the base end of the bobbin is capable of receiving a wide variety of styles and shapes of the base end portion of the bobbin. Then, since bobbin rings have only very few diameters, only a correspondingly small number of styles of base chuck are needed for the many different automatic loom bobbins commercially available.

Although an improved base chuck according to the present invention is useful generally in automatic loom bobbin winders, it finds its greatest utility in combination with mechanism for causing the tail end of a thread to be removed from the base chuck and wound into the body of yarn on the bobbin. A further object of the invention is therefore to provide an improved mechanism of this kind.

As will be evident, the chuck as is usual in automatic loom bobbin winders is adapted to receive the base end of an empty bobbin while the thread which leads to the previously wound bobbin extends across the face of the chuck, and, as usual, after the empty bobbin has been received in the chuck the thread leading to the previously wound bobbin can be cut by any usual cutting means. Unlike the usual arrangement, however, when the bobbin is held in my preferred form of chuck the thread will be clamped between the ring-engaging and centering surface of the chuck and the ring of the bobbin. Preferably, this manner of clamping the thread is taken advantage of, to facilitate removal of the thread end from a chuck in a simplified manner.

Further objects and advantages of the invention will be apparent from this specification and its drawings in which the invention is explained by description of a preferred example thereof.

In the accompanying drawings:

Fig. 1 is an enlarged vertical cross sectional view, taken on the axis of winding, showing a base chuck of the present invention holding the base end of a loom bobbin in centered position in a winding machine;

Fig. 2 is a diagrammatic view similar to Fig. 1 showing a new empty bobbin as having been delivered to the chuck, the thread from the thread guide engaged in the chuck, and the thread which formerly extended to the last wound bobbin severed close to the chuck;

Fig. 3 is a diagrammatic view similar to Fig. 2 showing the base of the bobbin as somewhat non-centered in the chuck, showing the thread about to leave the chuck 3 and alsoshowing the end of thread, in brokenlines, extending directly outwardly from the coils of thread wound on the body of the bobbin, after leaving the chuck;

,Pig. 4 is a. diagrammatic view similar toFig. 3 showing thewinding of the threadbunch on the bobbin after removal of the thread from the chuck;

Fig.5 isa diagrammatic view showing certain main elements of an automatic loom bobbin winder unit embodying the present invention;

Fig. 6 isafragmentary bottom view of the yarn cutter;

Fig. 7 is a diagram showing the actions of the group of actuating cams of. the .winder unit;

Fig..8 is a fragmentary view showing a hook substituted for the brush shown in Fig. and

Fig. 9.is a view'showing the hook ofFig. 8 viewed from its left side.

.In Fig. 5. a loom bobbin B is shown as held in a base chuck 10 which is carried by a driven spindle 11 and ina tip chuck13 which rotates on ball bearings 14 carried by a retractable slide 15. This general arrangement may be incorporated in both traveling and non-traveling winding units, and for simplicity of illustration is here shown as non-traveling.

Since the operations of changing bobbins automatically, and suitable mechanisms therefor, are well understood, they will be mentioned here only briefly.

Following completion of winding of a bobbin a cam shaft 20 is putinto operation, rotates through one revolution, and stops, in known manner. A group of earns 21- to 21- inclusive on this shaft 20 provide various motions involved in changing bobbins, in the proper sequence. Near the beginning of a single revolution, one cam 21 on shaft 20 operates through a bell crank 3i) to shift a driven clutch cone 3]. out of contact with its cooperating driving cone 32, thus stopping the spindle 11, the base chuck 10, and the bobbin.

Another cam 21 on shaft 20 acts through a bell crank 35, link 36, and lever 37 to retract the slide and tip chuck 13, allowing the wound bobbin to drop out of the chucks. With the tip chuck held retracted, a suitable magazine or empty bobbin holder presents an empty loom bobbin between the chucks, whereupon the tip chuck is allowed to close upon the bobbin and move the base end-of the bobbin into the base chuck 10.

Referring especially to Fig. 1 it will be observed that the chuck extends axially of the bobbin to engage and receive pressure from the endmost ring of the bobbin, and at its end face which engages with the ring is shaped to center the ring and hence center the base portion of the bobbin. Preferably the end surface of the chuck, engageable with the ring, is coucavely conically shaped. This surface is preferably that of a ring 10 of resilient material, for example rubber, which is inserted and secured within the main metallic body of the chuck ltl. Thus inaddition to centering the ring, the chuck has good frictional driving'engagement with the ring and through the ring, with the main body of the bobbin upon which the-ring tightly-fits.

'It will be'observed that the base chuck surrounds the base portion of the bobbin only loosely and exerts its final centering action on the bobbin altogether through the ring of the bobbin. Thus the chucks conical surface which'exerts the final centering action extends inwardly toward-the axis only far enough to accomplish this "final centering through the ring. The inner periphery of the ohuck,-which is preferably cylindrical or approximately so, is out of contact with the bobbin when the bobbin is finally centered as in Figs. 1 and 2 by the conical centering surface.

Very accurate centering of the bobbin is secured by this means, which permits the speed of winding to be increased without introducing objectionable vibration. Moreover accuracy of centering is not impaired by the inevitable slight distortions in the base end portion of the body of the bobbin or by the injuries which this end portion receives in the loom. Finally, the contour of the chuck is suitable for the variously shaped end portions of bobbins of the many various bobbin manufacturers.

My improved base chuck, unlike a conical interior center, affords a surface against which the thread can be reliably clamped by the bobbin without additional clamping means for this purpose.

As distinct from the final centering action which occurs when the bobbin becomes seated as in Figs. 1 and 2, the chuck may of course exert a preliminary or rough centering action upon the wood base of the bobbin in case the bobbin is presented to the chuck in sufficiently non-concentric relation.

Moreover, as will now appear, the chuck affords a means by which the bobbin may be held loosely and in slightly non-concentric relation during removal of an end of thread from the chuck.

Fig. 2 shows the thread guide '41 in the position occupied during the insertion .of the new empty bobbin in the chuck. Entry of the bobbin base into the chuck carries with it the thread leading from the thread guide to the discharged wound bobbin. The thread T then extends from the thread guide, in between the conical centering face of the chuck and the bobbin ring, thence over the end of the bobbin base, and out between the conical face of the chuck and the bobbin ring. This thread is cut close below the chuck by any suitable cutter. This cutter may include a stationary blade 45 and a movable blade 46 (Fig. 6) and be operated through a link 47 and bell crank 48 from a cam 21c on shaft 20.

With the thread thus clamped between the chuck and the endmost ring of the bobbin, the thread guide 41 is shifted over above the thread-receiving portion of the bobbin, the base chuck and bobbin are started rotating, and a few coils of thread are wound within a narrow zone. After the winding of these few coils of thread indicated at C in Fig. 3 there is no need for continued clamping of the thread end by the chuck, and it is advantageous to dispose of this end portion of thread at this time, in order to avoid continued fraying of its end and creation of fly or lint during the continued winding of the bobbin.

At this stage the chucks are slightly separated, for example a distance of inch or inch farther apart than in normal running. This is most conveniently accomplished by a low and short lobe on the previously mentionedcam 21 which operates the bell crank 35, link 36 and lever 37, to retract the tip chuck.

Fig. 3 shows how this slight separation releases the grip of the bobbin ring and chuck. The base end portion of the bobbin cannot leave the chuck but is loose and slightly eccentric in the chuck and makes no more than approximate line contact with the interior cylindrical surface of the chuck. Centrifugal force will then ordinarily remove the end of thread from the ring and chuck provided the rotation is sufficiently fast. However, preferably at this stage a brush 51 is moved into position to engage the portion of thread which extends between the coils on the bobbin and the chuck, as shown in Fig. 3, so that the brush exerts a detaining action upon this portion of thread, resisting rotation of this portion with the bobbin, and-thereby pulls the end from the chuck. The brush thus not only insures that the thread will leave the chuck but also permits operation at speeds at which the centrifugal force alone would be insuflicient to remove the thread. Brush 51 may be carried by a bell crank 52 which is operated by a cam 21 on shaft 20. Upon removal of the end of thread from the chuck, the brush is moved away from the bobbin.

Instead of a'brush for exerting a detaining action resisting rotation of the thread with the bobbin, a book may be. employed in similar manner. Figs. 8 and 9 show a .5 hook 51, substituted for the brush 51, the hook being shown in full lines in its operative position close to the bobbin and in broken lines in its inoperative position away from the bobbin. It may be noted that in its operative position the hook need not contact with the bobbin be cause when centrifugal force is insuflicient to remove the thread entirely from the chuck centrifugal force will nevertheless cause a certain ballooning-out of the thread, which will engage the thread with the hook.

The removed end of thread RT is shown in broken lines in Fig. 3 as extending freely outward from the coils on the bobbin. It will be understood however that this re moved end is quickly drawn onto the bobbin and covered with the winding thread T.

Only a few revolutions of the bobbin are needed to assure the removal of the end of thread from the chuck. Accordingly the tip chuck need only be held retracted for an instant.

As the tip chuck again forces the bobbin toward the base chuck, the conical end surface of the base chuck again centers the endmost ring of the bobbin in the normal running position.

Fig. 4 shows diagrammatically the preferred procedure by which the removed thread end RT is covered by the thread wound on the bobbin. It will be observed that the initial coils C are in the region occupied by the usual loom bobbin thread bunch, but do not extend to as great a Width nor to as near the base of the bobbin as does such usual thread bunch. During the winding of these coils C the thread guide 41 may either be held stationary or allowed to have a slight movement represented by S in Fig. 4. After the removal of the thread from the chuck the thread guide 41 is preferably allowed to have a traversing movement having a length of stroke S sufficient to wind the usual thread bunch, shown in outline at TB in Fig. 4. It will be noted that the bunch extends to both sides of the margin of the zone of coils C nearest to the base of the bobbin. During the winding of this bunch the thread T, running from the thread guide onto the bobbin, crosses several times the radial plane in which the removed thread end RT tends to rotate, thus drawing the removed thread end into the winding of the thread bunch so that the removed thread end is completely covered by the time the thread bunch has been wound and winding of the main portion of the thread package begins.

The cam diagram of Fig. 7 explains the timing of the actions of the several cams 21 to 21 that control respec tively the clutch 31, 32, the bobbin tip holder 13, the

thread cutter 45, 46 and the brush 51. In this diagram the lines 21 to 21 indicate rise, fall and dwell of these cams relative to the respective bell cranks controlled thereby. The diagram, which covers the 360 degrees rotation of the shaft 24 for a given bobbin change, is simplified by breaking away portions, whose durations may be very considerably varied, in which the positions of the parts controlled by the cams remain constant.

Beginning at the left portion of the diagram, at point I the cam 21 will have caused the clutch 31, 32 to stop the drive of the spindle, following which, at point 11 the cam 21* will have caused the tip holder 13 to retract to its full extent and discharge the bobbin from winding posi- In the middle portion of the diagram, at point III the cam 21* will have allowed the tip holder 13 to close upon a new empty bobbin and force it into the base chuck where it is centered as in Fig. 2, following which at point IV the cam 21 will have operated the cutter to cut the thread which extended from the base chuck to the discharged fully wound bobbin.

In the right portion of the diagram, at point V the cam 21 will have allowed the cone 31 to engage the cone 32 to start the spindle, following which at point Vi the cam 21t will have retracted the tip holder a short distance for a short time to allow the bobbin first to be loose in the base chuck, and then again be centered in the base chuck. At this same point VI the cam 21 will have held the brush 51 in position to assist in removal of the thread end from the base chuck while the bobbin is loose in the base chuck.

In the simplest form of the chuck, shown in Figs. 1, 2 and 3, during temporary separation of the holders for the tip and base, the base of the bobbin is supported by the inner peripheral surface of the chuck. Thus in addition to its concave conical centering surface, which engages the ring of the bobbin, the chuck provides a further surface for temporarily supporting the base, this further surface, however, being out of contact with the bobbin when the bobbin is centered by the centering surface; in Figs. 1 to 3 this further surface is defined by the inner periphery of the chuck. In other specific forms of the invention, such further surface may be defined by some other portion of the chuck, also out of contact with the bobbin when the bobbin is centered by the centering surface.

It has been pointed out above how the final centering action of the base chuck upon the bobbin is exerted alto- "gether through the bobbin ring by means of a concave centering surface, and that this provides advantages over constructions which center the bobbin by means of a cone which enters the bobbin bore, these advantages including greater accuracy of centering and suitability of the concave centering surface and the bobbin ring to clamp the thread without the provision of additional clamping means. It should also be pointed out that although a cone which enters the bore to center the bobbin would not be a reliable clamp for the thread end, there is nevertheless danger of the thread end occasionally being pinched between such a cone and the mouth of the bore. It has previously been proposed to provide, along with such cone that enters the bore to hold the bobbin centered, a thread clamp at the base of the bobbin, and to withdraw such thread clamp from the bobbin base while the bobbin was maintained centered by such cone. However with that construction, in case the thread end has happened to be pinched by the cone, the intended effect of withdrawing the thread clamp will be nullified by the continued holding of the thread by the centering cone and bobbin. Therefore, a further advantage of the invention is avoidance of this difiiculty, by concentrating the finalcentering and thread-clamping actions at the bobbin ring, and, during removal of the thread, allowing the bobbin to run in loose relation to the chuck.

I claim:

1. A winding machine for loom bobbins having rings around their bodies for positioning the bobbins in shuttles, the winding machine being of the type including opposed holders for the base and tip of the bobbin, the holders being arranged to press the bobbin axially between them, the holder for the base comprising a hollow chuck extending axially over the body portion of the base end of the bobbin and having a concave centering surface adapted to press against the endrnost ring of the bobbin, the chuck surrounding the said body portion only loosely so that final centering action of the chuck is exerted altogether through said ring.

2. A winding machine for loom bobbins having rings around their bodies for positioning the bobbins in shuttles, the winding machine being of the type including opposed holders for the base and tip of the bobbin, the holders being arranged to press the bobbin axially between them, the holder for the base comprising a hollow chuck extending axially over the body portion of the base end of the bobbin and having a generally cylindrical bore surrounding the said body portion loosely, said bore having a flaring mouth defining a centering surface for engagement with the endmost ring of the bobbin and adapted to clamp a thread between said centering surface and said ring, whereby the base end of the bobbin can be loosely supported in said bore during temporary separation of eared;

said holders, release'of-said clamping and removal of the'thread from between the ring'and centering surface.

3. A winding machine for loom bobbins having rings around their bodies for positioning the bobbins in shuttles, the winding machine being of the type including opposed holdersfor the base and tip of the bobbin, the holders being'arranged to press the bobbin axially between them, the holder for the base comprising a hollow chuck extending axially over the body portion of the base end of the bobbin and including an insert of resilient material, said insert having a conically-shaped centering surface for engagement with the endmost ring of the bobbin and adapted to clamp a thread between said centering surface and said ring and also having a generally cylindrical interior surface surrounding said body portion loosely, so as to permit removal of a thread from between said centering surface and ring during temporary separation of said holders.

4. Method of winding a loom bobbin which comprises centering the base end of the bobbin through the endmost ring of the bobbin with the end of thread clamped against said ring, rotating the bobbin to wind, and while the bobbin is rotating: allowing the base end to become eccentric, removing the end of thread from the ring, recentering the base end of the bobbin through said ring and allowing the end to be wound onto the bobbin.

5. Method of inserting a tail end of thread into the thread bunch formed at the start of winding a loom bobbin, comprising winding a few coils of thread within a narrow zone in the region to be occupied by the thread bunch but not extending so near to the base of the bobbin as will the completed thread bunch, holding the tail end of thread at the base of the bobbin during winding of said coils, and then causing the tail end to extend out from the rotating bobbin and imparting to the winding thread a traversing motion suitable to the Winding of a thread bunch extending to both sides of that margin of said zone which lies nearest to the base of the bobbin.

6. A winding machine for loom bobbins having rings for positioning the bobbins in shuttles, the winding ma- 1 chine being of the type including opposed holders for the base and tip of the bobbin, the holder for the base comprising a hollow chuck extending axially over the body portion of the base end of the bobbin to engage the endmost ring of the bobbin and also clamp a thread against said endmost ring, and the machine including means operative after a few coils of thread have been wound for automatically separating the holders sufliciently to permit said endmost ring and base chuck to release their clamping action upon the thread but not sutficiently to discharge the bobbin from its holders, the said base chuck being shaped to support the base of the bobbin in eccentric relation thereto while the holders are so separated.

7. A winding machine for loom bobbins having rings for positioning the bobbins in shuttles, the winding machine being of the type including opposed holders for the base and tip of thebobbin, the holder for the base comprising a hollow chuck extending axially over the body portion of thebase end of the bobbin to engage the endmost ring of the bobbin and also clamp a thread against said endmost ring, and the machine including means operative after a few coils of thread have been wound for automatically separating the holders sutficiently to permit said endmost ring and base chuck to release their clamping action upon the thread but not sufficiently to discharge the bobbin from its holders, the said base chuck surrounding the body portion of the base end of the bobbin loosely so as to permit the thread to leave the chuck while the thread is released from such clamping action.

8. A winding machine for loom bobbins having rings for positioning the bobbins in shuttles, the winding machinebeing of the type including opposed holders for the base and tip of the bobbin, the holder for the base comprising a hollow chuck extending axially overthe body portion of the base-end-of the bobbin to engage the-endmost ring of the bobbin and also clamp'a thread against said endmost ring, the holder for the tip being retractable to discharge the bobbin from its holders, and the machine including means operative after a few coils of thread have been wound for automatically retracting the tip holder sufiiciently .to permit said endmost ring and base chuck to release their clamping action upon the thread but not sufiiciently to discharge the bobbin from its holders, the said base chuck surrounding the body portion of the base end of the bobbin loosely so as to permit the thread to leave the chuck while the thread is released from such clamping action.

9. A winding machine for loom bobbins having rings for positioning the bobbins in shuttles, the winding machine being of the type including opposed holders for the base and tip of the bobbin, the holder for the base comprising a hollow chuck extending axially over the body portion of the base end of the bobbin and having a centering surface adapted to engage and center the endmost ring of the bobbin and also clamp a thread against said endmost ring, and the machine including means operative automatically after a few coils of thread have been wound for first causing the holders to separate sufficiently to permit said endmost ring and base chuck to release their clamping action upon the thread but not sufficiently to discharge the bobbin from its holders and then approach again so that the centering surface again centers said ring, the base chuck surrounding the body portion of the base end of the bobbin loosely so as to permit the thread to leave the chuck during such separation of the holders.

10. A Winding machine for loom bobbins having rings for positioning the bobbins in shuttles, the winding machine being of the type including opposed holders for the base and tip of the bobbin, the holder for the base comprising a hollow chuck extending axially over the body portion of the base end of the bobbin and having a centering surface adapted to engage and center the endmost ring of the bobbin and also clamp a thread against said endmost ring, the holder for the tip being retractable to discharge the bobbin from its holders, and the machine including means operative automatically after a few coils of thread have been wound for first causing the tip holder to retract sufficiently to permit said endmost ring and base chuck to release their clamping action upon the thread but not sufficiently to discharge the bobbin from its holders and then cause the tip holder to approach the base holder again so that the centering surface again centers said ring, the said base chuck surrounding the body portion of the base end of the bobbin loosely so as to permit the thread to leave the chuck while the thread is released from such clamping action.

ll. In a loom-bobbin winding machine of the type in which the winding bobbin is held between opposed holders for its tip and base, and an end of thread is clamped between a portion of the bobbin and a portion of the holder for the base, and the thread leading to said clamped end is guided onto the bobbin in coils by a thread guide, the combination of means for automatically separating the holders sufficiently to permit release of said clamping action while retaining the holders in sufiiciently close relation to maintain the ends of the bobbin held by their respective holders, and a member, engageable with a portion of the thread which extends between said coils and the base holder, for resisting rotation of this portion with the bobbin, thereby to pull the formerly clamped end from the base holder.

12. In a loom-bobbin winding machine of the type in which the winding bobbin is held between opposed holders for its tip and base, and an end of thread is clamped be tween a portion of the bobbin and a portion of the holder for the base, and the thread leading to said clamped end is guided onto the bobbin in coils by a thread guide,

the combination of means for automatically separating the holders sufliciently to permit release of said clamping action While retaining the holders in sufiiciently close relation to maintain the ends of the bobbin held by their respective holders, and a member adapted to brush against a portion of the thread which extends between said coils and the base holder, thereby to pull the formerly clamped end from the base holder.

13. In a loom-bobbin winding machine of the type in which the winding bobbin is held between opposed holders for its tip and base, and an end of thread is clamped between a portion of the bobbin and a portion of the holder for the base, and the thread leading to said clamped end is guided onto the bobbin in coils by a thread guide, the combination of means for automatically separating the holders sufiiciently to permit release of said clamping action while retaining the holders in sufficiently close relation to maintain the ends of the bobbin held by their respective holders, and a member movable into and out of position to engage a portion of the thread which extends between said coils and the base holder, and means for causing such movement of said member into threadengaging position in timed relation to the separating of the holders.

References Cited in the file of this patent UNITED STATES PATENTS 2,525,097 Hasler et a1. Oct. 10, 1950 2,718,360 Joyce Sept. 20, 1955 FOREIGN PATENTS 187,991 Switzerland Mar. 1, 1937 421,721 France Jan. 4, 1911