GB2233007A - Improved winding apparatus - Google Patents

Abstract

The present invention provides a cop winding machine 1 comprising a base means 2, mounting 3, a cop spindle and support means 4 formed and arranged for rotatably and axially displacing support 6, in use of the machine 1 and an elongate cop spindle 8, said machine including a rotary drive means 5 for rotary driving engagement with the cop spindle 8. An axially displaceable cop spindle axial drive means 11-14 is formed and arranged for axial driving engagement with the cop spindle 8. The machine also includes a yarn supply tension control 29-31 and a traverse bar 23 for reciprocably traversing a predetermined length of the cop spindle 8 while feeding yarn y onto the rotating cop spindle 8. The cop spindle axial drive means 11-14 progressively axially displaces the cop spindle 8 relative to the traverse bar 23 at predetermined rate so as to control the diameter of the cop winding while the traverse bar 23 traverses the predetermined length of the cop spindle at a predetermined variable rate generally related to the cop nose circumference therealong whereby the yarn y is wound onto the cop nose surface at a substantially constant tension. <IMAGE>

Description

IMPROVED WINDING APPARATUS The present invention relates to yarn winding apparatus and in particular to a cop winding machine for use in winding of yarn into a cop for use in the weft yarn supply of a loom.

Modern looms generally operate at very high speeds and it will therefore be appreciated that as the weft yarn rapidly traverses the shed of a loom it should unwind freely and smoothly in order to avoid excessive variation in the tension therein which can on the one hand result in breakage of the yarn due to excessively high tension and on the other hand in formation of loops in the weft yarn and tangling thereof due to excessively reduced tension.

A particular problem in achieving a well-formed cop which avoids such problems, is the significant variation in cop winding tension required for yarn of different material, weight, etc., and the relatively narrow limits within which the tension requires to be set and to be maintained. Previously known cop-winding machines use a generally upstanding winding spindle and an end stop loaded with weights to push downwardly on the cop to maintain the tightness and density of the cop during winding thereof. On the one hand this results in a relatively cumbersome and inexact means for adjustment of the end loading and hence the tightness and density of the cop, and on the other hand, results in a relatively large effective inertial mass of the end stop during the retraction and reinsertion thereof in the cop ejection phase resulting in considerable additional stress etc., in the machine.

Considerable further problems can also still arise even when other means are used to obtain a closer control of the cop winding characteristics in order to obtain better winding characteristics, due to ever higher performance required in modern weaving looms. These include higher operating speeds in general and also wider looms which can weave material in widths of up to 30 metres or more. This requires on the one hand higher speeds and acceleration in order to project the shuttle from one side of the loom to the other, and on the other hand, very high deceleration forces in order to stop the shuttle as it arrives at the other side of the loom, within a short distance which may be as little as one metre or less.

Another significant problem that arises with higher performance looms is that it becomes ever more important to achieve maximum possible consistency within the cop winding which in turn requires maximum consistency of yarn tension during cop winding. With a conventional traverse bar it may be noted though that as the traverse bar moves between the smaller and larger diameter ends of the nose of the cop, the angle of the yarn onto the cop will vary considerably. This in turn will result in a significant variation in the friction to which the yarn is subjected so that no matter how carefully controlled the yarn tension upstream of the traverse bar, there will result in a significant variation in the yarn as it is actually laid onto the cop nose.A particular problem that arises with some woven material such as those used in paper making and which require to undergo a thermal pre-treatment or conditioning before use, is that of differential stretching and/or shrinkage resulting in significant deviations from the perfectly plane form required in use of the fabric. This differential stretching or shrinkage has been found to arise as a result of thermal inhomogeneities in the yarn due to this having been subjected to localised heating arising from variations in the frictional forces to which the yarn was subjected during winding thereof onto a cop spindle.

It is an object of the present invention to avoid or minimise one or more of the above disadvantages.

The present invention provides a cop winding machine comprising a base means rotatably mounting a spindle means comprising a support spindle formed and arranged for rotationally drivingly engaging and axially freely displaceably supporting, in use of the machine, one end of an elongate cop spindle and provided with a rotary drive means, an axially displaceable cop spindle axial drive means formed and arranged for axially driving engagement with said cop spindle in use of the machine, said machine including yarn supply tension control means, and traverse bar means for reciprocably traversing a pre-determined length of the cop spindle in use of the machine while feeding yarn-onto the rotating cop spindle, said cop spindle axial drive means being formed and arranged for progressively axially displacing said cop spindle relative to said traverse bar means at a predetermined rate so as to control the diameter of the cop winding in use of the machine and said traverse bar means being formed and arranged for traversingsaid predetermined length of the cop spindle at a predetermined variable rate generally proportional to the cop nose circumference therealong whereby the yarn is wound onto the cop nose surface at a substantially constant tension in use of the machine.

With a cop winding machine of the present invention it is possible to wind cops more evenly than has been possible heretobefore and without subjecting the yarn to variations in frictional forces and localised heating. More particularly the yarn is supplied to the cop spindle at the larger diameter end of the cop nose at a faster rate (the traverse bar moving more slowly thereat) than at the narrower diameter end of the cop nose (the traverse bar moving more quickly thereat). It is also possible to provide a cop winding machine of the invention which produces stronger cops which can withstand the much greater forces involved in looms operating at high speeds and with large weaving widths.

In addition the present invention allows one to dispense with the need for the specially designed tapered cop winding cones previously used which had to be individually tailored to different yarn materials. In general the traverse bar means comprises a traverse bar connected via a drive transmission linkage to a traverse bar drive means. Conveniently there is used a rotary drive means and said linkage means is formed and arranged for converting rotary drive into a modulated reciprocating movement.

Advantageously the linkage comprises a link member formed and arranged for sliding reciprocal movement relative to a rotary drive member, and having an engagement portion in guided engagement with an eccentrically mounted generally egg-shaped camming guide on said rotary drive member, so as to provide a modulated reciprocal movement of said link member.

Various forms of cop support spindle may be used in the spindle means of the present invention. In general the cop spindle will be in the form of a non-circular section bar, such as a polygonal e.g. hexagonal, section, or a substantially circular section with at least one 'flats, the support spindle having a complementary section bore for receiving one end of the bar with a sliding fit. Advantageously, the support spindle bore sides are provided with a plurality of bearing means, e.g. needle roller bearings, to facilitate free relative movement of the cop spindle relative to the support spindle as the former is progressively displaced.

Desirably, the said cop spindle has at its second end a nut formed and arranged for supporting the beginning of a yarn length to be wound thereonto in use of the machine, for engagement with the axial drive during cop winding, and for engagement with a weaving loom cop support in use of the completed cop.

Advantageously the machine is provided with drive control means formed and arranged for varying the relative speeds of movement of the spindle means and the traverse bar i.e.

the ratio of the rotational speed of spindle means to the rate of reciprocation of the traverse bar. Conventional machines have fixed ratios such as 2.8 (that is the rotational speed in r.p.m. of the spindle means is 2.8 times the number of strokes per minute which the traverse bar executes). Conveniently the machine is provided with separate drive motors for the spindle means and for the traverse bar, each provided with a continuously variable speed control.

It has also been found that substantially higher ratios of from 5 to 10 have significant advantages in permitting a higher yarn density to be achieved and a stronger cop i.e. one which is more resistant to large g forces, to be produced.

Thus in a further aspect the present invention provides a cop winding machine having a ratio of spindle rotation speed in r.p.m. of from 5 to 10 times the reciprocation rate in strokes per minute of the traverse bar.

The present invention also provides in another aspect a yarn tensioning device of particularly simple and economic structure, which is suitable for use in a cop winding machine of the invention, and which device comprises an elongate bar member having at opposite ends respective yarn guide means, at least one of said yarn guide means being mounted on said bar so as to be rotationally displaceable between a plurality of different positions in which it can be secured, thereby to vary the length of a helical pathway extending around said bar between the yarn guide means and thence the friction between the bar and a yarn extending along said pathway in use of the device.

In a still further aspect the present invention provides a traverse bar suitable for use in a cop winding machine wherein is provided a yarn guide aperture which is in the form of a substantially elongated slot having a length of a generally similar order to the cop winding diameter capacity of the machine, said slot extending generally at right angles to the reciprocating axis of said traverse bar.

With a traverse bar of the present invention the yarn may move freely across the reciprocating axis of the traverse bar and thus across the spindle means axis as the traverse bar is reciprocably displaced along the length of the nose, guiding the yarn for winding about respectively increasing and decreasing diameter parts of the nose. In this way the variation in the contact angle between the yarn and the cop between the smaller and larger diameter ends of the nose is considerably reduced.

This in turn tends to reduced variation in friction in the yarn just as it is being wound onto the cop and hence the variation in tension in this part of the yarn is reduced, resulting in more consistent winding of the cop.

Advantageously, the spindle means is mounted substantially horizontally in order substantially to eliminate any variations in loading due to gravitational effects during the build up of a cop.

Desirably the yarn supply tension control means comprises a multi-stage adjustable tensioning means formed and arranged to apply a closely controlled relatively high tension to the yarn whilst minimising friction effects etc. on the yarn. Advantageously also there is used a weft accumulator of generally known type as used in shuttleless looms, and such is as available from the Techomatex SA company of Bedano, Switzerland, in order to control snatching and help regulate tension in the yarn during cop winding.

Further preferred features and advantages of the invention will appear from the following detailed description given by way of example of a preferred embodiment illustrated with refernce to the accompanying drawings in which; Fig. 1 is a front elevation of the main part of an automatic cop-winding machine of the invention; Fig. 2 is a partial plan view of the machine of Fig. 1; Fig. 3 is a partial rear view of the machine of Fig. 1 showing generally the yarn supply and tension means; Fig. 4 is a detail elevation of the traverse bar drive transmission linkage of the machine of Figs. 1 to 3; Fig. 5 is an end view of a preferred support spindle; and Fig. 6 is a longitundinal section of the support spindle of Fig. 5.

Fig. 1 shows a cop winding machine 1 comprising a base means 2 rotatably mounting 3 a horizontal support spindle 4 provided with a first, rotary drive, motor 5. The support spindle 4 has an axial bore 6 for receiving with a sliding fit therein one end 7 of a cop spindle 8 (shown in a position ready for feeding from a cop spindle magazine 9 by a suitable transfer device 10 up to and into engagement with the support spindle 4) (see Fig. 3) and rotational driving engagement with said one cop spindle end 7 (see also Fig. 5 description below).

An axially displacable cop spindle axial drive means comprises an annular support 11 (see Fig.2) mounted 12 concentrically with support spindle.4with resiliently biased engagement means formed and arranged for releasably gripping the nut end d cop spindle 8 mounted in said support spindle 4 in use of the machine for winding of yarn y thereonto to form a cop.The axial drive cop spindle mounting 12 is drivingly engaged with an elongate screwthreaded rod 13 which is rotatably driven by a drive motor 14 for progressibly advancing the axial drive cop spindle mounting 12 and thereby the axial drive annular support 11 and a cop spindle 8 engaged therewith, away from the support spindle 4 at a steady predetermined rate corresponding to winding on of yarn Z onto the cop spindle 8 at a predetermined diameter during a cop winding phase and for returning the annular support 11 after a cop ejection phase and new cop spindle insertion phase, to its starting position adjacent the support spindle 4. The screw drive motor is provided with a speed control 15 for setting of the cop spindle advance rate to a desired value according to the nature of the yarn being wound and its tension and other desired cop characteristics such as winding diameter A yarn supply means comprises a reciprocably displacable yarn traverse bar 23 which is drivingly connected to a second motor 24 via a linkage 25 (further described hereinbelow) formed and arranged for reciprocating displacement of a yarn holding eye in the form of a narrow elongate slot 26 having a length of a generally similar order to the cop diameter capacity of the machine, along the exposed upstream end portion 27 of the cop spindle 8 and thus along the nose of the cop i.e. the tapered end of the cop (or partially formed cop) on which the yarn is laid during winding of the cop.

The yarn y is fed to the traverse bar 23 from a weft accummulator 28 of generally known type as used in shuttle-less looms controlling snatching of the yarn and generally maintaining yarn tension constant as well as to some extent reducing yarn twist (suitable apparatus is available from Technomatex S.A. of Bedano, Switzerland), via a yarn tensioning means comprising a plurality of serially arranged yarn tensioning means including a roller drag ring unit 29 which has two diametrically opposed ceramic rods 29a around which the yarn y is passed, the ring unit 29 being angularly displacable by a central control knob 30 to vary the length of yarn y in contact with the rods 29a and hence the tension in the yarn y in a carefully controlled progressive manner so as to minimise local friction to avoid slackening, looping etc. of the yarn during the return stroke of the traverse bar 23. As may be seen in Fig. 3, there is desirably also used a new yarn tensioning device 31 provided by the present invention which comprises an elongate cylindrical body 32 having fixed movable yarn guides 33, 34 each in the form of an annular member 35 with a notch 36 extending radially inwardly to the cylindrical surface 37 of the body 32.

The movable guide 34 is axially displacable between a projecting freely rotatable position and a retracted position (as illustrated) in which it interlocks with the body 32 in any one of a plurality of angularly distributed positions, thereby to vary the length of a helical yarn pathway 38 extending around the body 32 between the fixed and movable sides 33, 34 hence varying the friction to which the yarn is subjected to by this device 31, which will in turn vary the tension exerted by the device 31. The tension in the yarn y being supplied to the traverse bar 23 is monitored by a conventional tension meter T of the type having a spring biased plunger which presses downwardly onto a short length of the yarn y.

In use of the cop winder, yarn ffi is unwound from a yarn supply package p, fed through the pensioners 29, 31 and progressively built up on the cop spindle 8 by the action of the traverse bar 23 as the cop spindle 8 withdraws from the support spindle 4 with the progressively retreating annular support 11. When the required cop length has been reached (or alternatively the required length of yarn conveniently determined by an optical counter roller device OC provided upstream of the yarn tensioning means), the annular support 11 is retracted and disengaged from the cop spindle 8, allowing the completed cop on its spindle 8 to be gripped by a transfer device 40 and withdrawn fully from the support spindle 4 and then downwardly ejected.The yarn y immediately upstream of the cop is then gripped by jaws 41 below the support spindle 4 and held therein while a new cop spindle 8 is fed into the support spindle 4 and the yarn above the jaws 41 engaged by a prong 42 on the cop spindle 8, and the yarn below the jaws 41 cut. The completed cop may then be removed entirely and winding of the new cop commenced.

The first and second drive motors 5, 24 are provided with independent, continuously adjustable, speed controls 43, 44 which allows not only for winding speed to be adjusted but also for further parameters such as cop winding density readily to be varied through the variation of the ratio of traverse bar reciprocation rate to spindle rotation. Advantageously the machine includes a processor means 45 formed and arranged for driving a suitable visual display unit 46 to show the actual ration at any given time. Thus with a spindle rotation speed of 1500 r.p.m. and stroke rate of 250 per minute there would be displayed a ratio of 6.0.

The traverse bar drive linkage is formed and arranged with at least one adjustable pin and slot connection 47, between an eccentric arm 48 and a rocker arm 49 to allow the length of the traverse bar stroke to be adjusted readily, for varying the length of the nost of the cop.

The eccentric arm 48 has an elongate slot 50 through which extends a central pin 51 for captive reciprocal sliding movement of the eccentric arm 50 across the face 52 of a rotary drive plate 53. The eccentric arm 50 additionally has a pin 54 which slidably engages in an eccentrically disposed generally eggshaped, in plan view, camming guide slot 55 in the face 52 of the rotary drive plate 53 so as to provide a modulated reciprocal displacement of the eccentric arm 48 during constant speed rotation of the drive motor 24 and drive plate 53.

As shown in Fig. 4 the guide slot 55 has its larger radius end closer to the central rotational axis of the drive plate 53 and its smaller radius end further away therefrom. Fig. 4 also shows two end limit positions and an intermediate position of the eccentric and rocker arms 48, 49 and corresponding angular positions of the rotary drive plate 53. Incidentally it may be noted that in Fig. 4 only the centre line of the guide slot 55 has been indicated for the purposes of clarity.

Since the guide slot configuration is adapted for maintaining constant yarn feeding across a cop nose of a particular predetermined shape, it is desirable, in order to maintain constant yarn treatment throughout substantially the whole of the cop, that the cop spindle nut 56 should have a tapered shape 57 corresponding generally to that of the cop throughout its length as it is built up.

As explained above, the new cop spindle of the present invention eliminates the need for precisely designed tapered cop winding spindles whose angle of taper and frictional properties had to be carefully tailored to the frictional and other properties of individual yarn types. Thus insofar as the new machine does not require such an individually tailored component it will be appreciated that it can be used readily with a wide range of different yarn materials, even including yarn materials which it has not previously been possible to wind in this way.

It may also be noted that by using a rigid spindle to support the full length of the cop, the yarn may be wound substantially more tightly and thus more densely than has heretofore been possible thereby increasing wound yarn length e.g. by 30% or more. Particularly significantly though, the yarn is wound onto the cop with very little variation in yarn tension despite the constantly varying winding diameter on the cop nose and with minimal variations in friction and hence in the thermal 'history' of the yarn so that when the yarn is eventually incorporated into a fabric there will be minimal variation in behaviour across the fabric after any thermal processing or conditioning of the fabric such as may be required for fabrics used under thermally severe conditions.

In order to prevent undesired unwinding of the yarn during transfer of the completed cop from the winding machine, the latter desirably includes a glue application device (not shown) formed and arranged for applying a small spot of glue to the nose of the cop to seal the free end portion of yarn thereon whilst at the same time allowing the "seal" readily to be broken when the cop is about to be used.

It will be appreciated that various modifications may be made to the above embodiment without departing from the scope of the present invention. Thus for example whilst the support spindle axial bore 6 could simply have a non-circular section corresponding to that of the cop spindle 8, preferably there is used a circular section bore 58 havinga:bush 59 as shown in Fig. 5 in conjunction with a plurality of needle bearing units 60 angularly spaced around its entrance 61. The bearing units 60 each comprise a roller 62 mounted 63 on one arm 64 of a bell-crank lever. 65 whose other end is engaged by a resilient biasing means in the form of a helical spring 66 as to urge the roller 62 radially inwardly of the support spindle 4.A grub screw 67 engages a distal end of the spring 66 to adjust the compression of the spring and hence the radially inward gripping pressure between the roller 62 and the cop spindle 8. The rollers 62 are mounted so that their rotational axis extend generally chord-like across the support spindle bore 60. With such an arrangement the bearing units 60 are readily pivotable so the rollers 62 move outwardly to facilitate insertion of the cop spindle 8 into the support spindle bore 6 and automatic centering thereof whilst at the same providing secure rotational driving engagement with one or more flats 69 on the outer surface 70 of a cop spindle 8 inserted into the support spindle bore 58.

Fig. 7 is a detail sectional plan view through the support spindle and cop spindle drive, of a further embodiment of a cop winding machine of the invention.

In more detail this particular embodiment is adapted for use with a cop spindle 71 which has a completely round external surface i.e. without any flats 69 as in the case of the cop spindle 70 shown in Fig. 5. For this reason this embodiment uses a modified form of cop spindle drive wherein a first drive pulley 72 is fixedly mounted on the tubular support spindle 4 and transfers rotary drive from said support spindle via a drive belt 73 and a second drive pulley 74 fixedly mounted on a rotary drive shaft 75.

The drive shaft 75 is mounted parallel to the central rotational axis of the support spindle 4 and is rotatably mounted at one end 76 proximal the support spindle 4 in a suitable bearing 77 mounted on and to one side of the support spindle 4. Towards its other end 78 the drive shaft 75 is provided with a longitudinally extending groove 79 and is rotatably mounted 80 in the axial drive cop spindle mounting 12 which is drivingly engaged with a rotatably driven elongate screwthreaded rod (not shown) in similar manner to that shown in Fig. 2 for axial displacement of the spindle mounting 12.A third drive pulley 81 is mounted for rotary driving engagement with the drive shaft 75 via suitable pin or ball interengagement means 82 extending from said third drive pulley 81 radially into said groove 79 so as to transfer rotary drive between the drive pulley 81 and drive shaft 75 whilst permitting free axial movement of said third drive pulley 81 along said drive shaft 75 as the spindle mounting 12 is axially displaced.

The third drive pulley 81 transmits rotary drive to a cop spindle mounting collet 82 rotatably mounted 83 on part 84 of said spindle mounting 12, via a drive belt 85 and a fourth drive pulley 86. The collet 82 has an axially retractable cop spindle engagement head 87 provided with circumferentially spaced jaws 88 which are resiliently biased radially outwardly at their distal ends 89 so as to adopt a splayed out configuration in the axially extended position of the head 87 shown in Fig. 7 allowing insertion of the enlarged diameter rear driven end 90 of the cop spindle 71 therebetween. When the head 87 is retracted, via an axially extending control rod 91, the jaws 88 are drawn into a reduced -internal- diameter portion 92 of the collet shell 93, and thereby forced radially inwardly captively to engage the cop spindle end 90.

As may be seen in Fig. 7, the rear face 94 of said cop spindle end 90 has a slot-form recess 99 for driven interengagement with a pair of angularly spaced axially projecting pins 95 which transmit rotary drive from the collet 82 to the cop spindle 71.

The reduced diameter forward end 96 of the cop spindle 71 is supported by an annular collar 97 which is freely axially slidable along the hollow interior 98 of the support spindle 4 whereby the cop spindle 71 remains supported at its forward end 96 substantially throughout the cop winding process as the cop spindle 71 is progressively retracted away from said support spindle 4 by the axial drive cop spindle mounting 12.

With the above described cop spindle drive arrangement it is possible to utilise a cop spindle with a completely round outer surface onto which the yarn y is wound thereby avoiding any variation in winding or unwinding of yarn onto and off the cop spindle due to flats or other like irregularities on the cop spindle outer surface.

For the avoidance of doubt it should be noted that as used herein the term "cop" indicates a yarn package wound onto a spindle or tube support, and especially such a package for use in supplying the weft thread in a shuttle of a loom.

In one aspect the present invention provides a cop winding machine comprising a base means rotatably mounting a spindle means comprising a support spindle formed and arranged for rotationally drivingly engaging and axially freely displaceably supporting, in use of the machine, one end of an elongate cop spindle and provided with a rotary drive means, an axially displaceable cop spindle axial drive means formed and arranged for axially driving engagement with said cop spindle in use of the machine, said machine including yarn supply tension control means, and traverse bar means for reciprocably traversing a pre-determined length of the cop spindle in use of the machine while feeding yarn onto the rotating cop spindle, said cop spindle axial drive means being formed and arranged for progressively axially displacing said cop spindle relative to said traverse bar means at a pre-determined rate so as to control the diameter of the cop winding in use of the machine and said traverse bar means being formed and arranged for traversing said pre-determined length of the cop spindle at a predetermined variable rate generally proportional to the cop nose circumference therealong whereby the yarn is wound onto the cop nose surface at a substantially constant tension in use of the machine.

Claims (18)

1. A cop winding machine comprising a base means mounting a cop spindle support means formed and arranged for rotatably and axially displaceably supporting, in use of the machine, an elongate cop spindle at at least one end portion, - said maåLne including-a rotary drive means formed and arranged for rotary driving engagement, directly or indirectly, with the cop spindle, and axial drive means formed and arranged for axially driving engagement, directly or indirectly, with said cop spindle, in use of the machine, said machine including yarn supply tension control means, and traverse bar means for reciprocably traversing a pre-determined length of the cop spindle in use of the machine while feeding yarn onto the rotating cop spindle, said cop spindle axial drive means being formed and arranged for progressively axially displacing said cop spindle relative to said traverse bar means at a pre-determined rate so as to control the diameter of the cop winding in use of the machine and said traverse bar means being formed and arranged for traversing said pre-determined length of the cop spindle at a pre-determined variable rate generally related to the cop nose circumference therealong so that the yarn is wound onto the cop nose surface at a substantially constant tension in use of the machine.

2. A machine as claimed in claim 1 wherein said cop spindle support means comprises at least one tubular spindle means formed and arranged for rotatably supporting said at least one cop spindle end portion.

3. A machine as claimed in claim 2 wherein a said tubular spindle means is formed and arranged for rotationally drivingly engaging and axially freely displacably supporting said at least one cop spindle end portion.

4. A machine as claimed in claim 3 for use with a cop spindle having a non-circular section outer surface portion, wherein the tubular spindle means has a complementary section bore for receiving one end of the cop spindle with a sliding fit.

5. A machine as claimed in claim 3 or claim 4 wherein is provided a second tubular spindle means formed and arranged for axially driving engagement with a cop spindle end portion, and wherein said axial drive means is formed and arranged for axially driving said second tubular spindle means.

6. A machine as claimed in claim 2 for use with a cop spindle having a rotary drive engagement portion disposed radially inwardly of a generally circular section outer surface, wherein the tubular spindle means is formed and arranged for driving engagement with a said cop spindle rotary drive engagement portion.

said tubular

7. A machine as claimed in claim 6 wherein said tubular spindle means is formed and arranged so as to be in axially driven engagement with said axial drive means.

8. A machine as claimed in claim 5 or claim 6 wherein is provided a second tubular spindle means formed and arranged for rotatably supporting a cop spindle end portion remote from that supported by the first tubular spindle means, so that said remote cop spindle end portion is freely axially displacable in said second tubular spindle means.

9. A cop winding machine comprising a base means rotatably mounting a spindle means comprising a support spindle formed and arranged for rotationally drivingly engaging and axially freely displaceably supporting, in use of the machine, one end of an elongate cop spindle and provided with a rotary drive means, an axially displaceable cop spindle axial drive means formed and arranged for axially driving engagement with said cop spindle in use of the machine, said machine including yarn supply tension control means, and traverse bar means for reciprocably traversing a pre-determined length of the cop spindle in use of the machine while feeding yarn onto the rotating cop spindle, said cop spindle axial drive means being formed and arranged for progessively axially displacing said cop spindle relative to said traverse bar means at a pre-determined rate so as to control the diameter of the cop winding in use of the machine and said traverse bar means being formed and arranged for traversing said pre-determined length of the spindle means at a predetermined variable rate generally proportional to the cop nose circumference therealong whereby the yarn is wound onto the cop nose surface at a substantially constant tension in use of the machine.

10. A machine as claimed in any one of claims 1 to 9 wherein said traverse bar means comprises a traverse bar connected via a drive transmission linkage to a traverse bar drive means, said linkage comprising a link member formed and arranged for sliding reciprocal movement relative to a rotary drive member, and having an engagement portion in guided engagement with an eccentrically mounted generally egg-shaped camming guide on said rotary drive member, so as to provide a modulated reciprocal movement of said link member.

11. A machine as claimed in any one of claims 1 to 10 which machine is provided with drive control means formed and arranged for varying the relative speeds of movement of the cop spindle rotary drive means and the traverse bar thereby to vary the ratio of the rotational speed of the cop spindle to the rate of reciprocation of the traverse bar in use of the machine.

12. A machine as claimed in claim 11 wherein are provided separate drive motors for the cop spindle drive means and for the traverse bar, each provided with a continuously variable speed control.

13. A machine as claimed in any one of claims 10 to 12 wherein the ratio of cop spindle rotation speed in r.p.m.

to the reciprocation rate in strokes per minute of the traverse bar is from 5 to 10:1.

14. A cop winding machine having a ratio of cop spindle rotation speed in r.p.m. to the reciprocation rate in strokes per minute of the traverse bar of from 5 to 10:1.

15. A machine according to any one of claims 1 to 14 wherein the traverse bar is formed and arranged for traversing said predetermined length of the cop spindle at a predetermined variable rate generally directly inversely proportional to the cop nose circumference therealong.

16. A machine according to any one of claims 1 to 15 wherein said traverse bar has a yarn guide aperture in the form of a substantially elongated slot having a length of a generally similar order to the cop winding diameter capacity of the machine, said slot extending generally at right angles to the reciprocating axis of said traverse bar.

17. A machine according to any one of claims 1 to 16 wherein is provided a yarn tensioning device comprising an elongate bar member having at opposite ends respective yarn guide means, at least one of said yarn guide means being mounted on said bar so as to be rotationally displaceable between a plurality of different positions in which it can be secured, thereby to vary the length of a helical pathway extending around said bar between the yarn guide means and thence the friction between the bar and a yarn extending along said pathway in use of the device.

18. A cop winding machine substantially as described hereinbefore with particular reference to Figs 1 to 6 or Figs 1 to 6 as modified by Fig. 7 of the accompanying drawings.