Winding apparatus

Abstract: A yarn winding apparatus comprises two clutches (20,21), the input sides of which are continuously driven in opposed directions by a motor (18) or by respective motors (18,19). At any given moment one of the clutches (20) is engaged whilst the other (21) is disengaged, so that yarn traversing apparatus (13,14) is driven in a first direction to move the yarn (12) in one direction along a traverse path to a predetermined end of stroke location, whereupon a control device (22) causes disengagement of the one clutch (20) and engagement of the other clutch (21) to drive the yarn traversing apparatus (13,14) in the opposite direction and hence the yarn (12) in the reverse direction along the traverse path. Preferably the clutches (20,21) are electrorheological fluid or magneto-rheological suspension clutches, each of which is coupled to a respective one of two spaced pulleys (15,16) around which travels an endless band (14), having a traversing yarn guide (13) thereon. The control device (22) may be programmable to vary the traverse speed and end of stroke locations to avoid patterning and ridged or collapsed package ends.

Description: This invention relates to yarn winding apparatus, and in particular to apparatus for traversing a running yarn to and fro parallel with the surface of a package on which the yarn is being wound. There are many differing types of apparatus for producing the required traversing motion. For example, in one type of traversing apparatus the yarn is engaged by a yarn guide mounted on a reciprocating rod. In another type, the yarn is engaged in an endless helical groove, or by a guide held in such a groove, provided in the surface of a roller rotating about an axis parallel with that of the package. In yet another type, the yarn is successively engaged by two yarn guides which are each mounted on one of two oppositely moving endless belts. Alternatively the yarn may be successively engaged by each of two oppositely rotating guide arms. In GB-A-1531779 (FR-A-2332216) there is disclosed a winding apparatus according to the preamble of claim 1 which comprises a motor driving two spring loaded magnetically actuated clutches, to of each of which is connected a respective pulley. An endless belt having attached to it a guide carriage for the wire or like material, is driven by one of the pulleys dependent upon which of the clutches is engaged. The two clutches are driven in the same rotary direction, and the pulleys contact opposed sides of the belt so that by alternating the engagement of the clutches the belt is driven in opposed directions to cause the guide to reciprocate. Each of these known types of traversing apparatus has its own disadvantages. For example the apparatus of GB-A-1531779 is suitable for the relatively low speed winding of wire and like material but is unsuitable for the high speed winding of textile yarn due to the response time of the clutches and the relatively high inertia of the driven parts whose direction of motion is required to alternate. This causes the turnround time of the traversing guide carriage to be excessive for the purpose of winding textile yarns, leading to ridged and possible collapse of the package ends, and unsatisfactory unwinding characteristics of the resulting package. Similarly the other known devices have disadvantages mainly related to the inertia of the moving parts at the turnround points at the ends of the traverse stroke, the transfer of the yarn from one groove or guide to the other, or the ability to provide in the apparatus means for avoiding patterning on the package and/or ridged or collapsed package ends. For each of the above-mentioned types of traverse apparatus, mechanisms and arrangements have been devised to avoid or minimise the disadvantages pertaining to the particular type of apparatus, with varying degrees of success. However all of such mechanisms and arrangements tend to complicate the traverse apparatus and increase considerably the cost of the textile machine on which such traverse apparatuses are fitted. Traverse mechanisms as described above require lubrication, frequent maintenance and adjustment, and tend to be very noisy. Furthermore such traverse mechanisms are designed such that the turn round characteristics are as good as can be achieved with the design concerned at the maximum design speed of operation of the mechanism. In consequence, when the machine is run at a lesser speed or wind angle as may be desirable for certain yarn processing applications, the dwell time at the end of each stroke is increased, thereby increasing the problems of ridged or collapsed package ends. It is an object of the present invention to provide a yarn winding apparatus, in particular a traverse mechanism, which avoids or minimises the above-mentioned disadvantages, but in a relatively simple and cost effective manner. The invention provides a winding apparatus for winding a textile yarn at a substantially constant speed onto a package; comprising yarn guide means, drive means which is continuously operable in a driving direction, coupling means comprising two clutches each of which has an output side drivingly engaged with the yarn guide means, which coupling means is operable in a first operating condition to engage the yarn guide means with the drive means whereby the yarn guide means is driven in one direction to move the yarn in a first direction along a traverse path, and then in a second operating condition to re-engage the yarn guide means with the drive means whereby the yarn guide means is driven in the opposed direction to move the yarn in the reverse direction along the traverse path, at least one sensing device operable to provide an electrical signal as the yarn reaches a predetermined location on the traverse path, and control means which is operable in response to the signal to change the coupling means from one to the other of the operating conditions when the yarn reaches the predetermined location, characterised in that the clutches are driven in opposed directions and each clutch comprises a rheological fluid which is responsive to electrical excitation wherein in one operating condition one of the clutches is electrically excited to engage the yarn guide means with the drive means and the other clutch is de-energised, and in the second operating condition the one clutch is de-energised and the other clutch is electrically excited to engage the yarn guide means with the drive means, and the control means is operable to excite the de-energised clutch and de-energise the excited clutch to change the coupling means from one operating condition to the other. The yarn guide means may comprise a yarn guide mounted on an endless band. The band may be a belt, cable or cord, and may be disposed to travel around two spaced pulleys mounted for rotation about substantially parallel axes. Alternatively the yarn guide means may comprise a cam roller having a helical groove in the cylindrical surface thereof. The drive means may comprise two motors, each motor being continuously operable in a respective driving direction and drivingly engaged with a respective one of the clutches, whereby the input sides of the clutches are driven in opposed directions. Alternatively a single motor continuously operable in a driving direction may be drivingly engaged with the two clutches whereby the input sides of the clutches are driven in opposed directions. The control means may comprise programmable means, in which case the predetermined location on the traverse path, reached by the yarn when the coupling means is changed from one operating condition to the other, may be varied for successive motions along the yarn path. The control means may also be operable to vary the speed of rotation of the drive means during the changes of operating condition of the coupling means and/or between successive changes thereof. The clutches may each comprise an electrorheological fluid or magneto-rheological suspension clutch, whereby the control means is operable to electrically energise the fluid or magnetically energise the suspension of one clutch and deenergise the fluid or suspension of the other clutch to change the coupling means from one operating condition to the other. The invention will now be further described with reference to the accompanying drawings in which: Fig. 1 is a front elevation of the yarn guide means of one embodiment, Fig. 2 is a plan view of the embodiment of Fig. 1, Fig. 3 is a plan view of a second embodiment, Fig. 4 is a plan view of a third embodiment, and Fig. 5 is a plan view of a fourth embodiment Referring now to Figs 1 and 2, there is shown a package 10 rotatably mounted in a cradle 11 of a textile machine, and on which a yarn 12 is being wound. The package 10 is driven by contact of its peripheral surface with that of a driving bowl (not shown) which is itself driven at a constant speed of rotation so that the speed of take-up of the yarn 12 by the package 10 is substantially constant as the package diameter increases. As the package 10 rotates, the yarn 12 is traversed axially of the package 10 by means of a traversing yarn guide 13. The guide 13 is secured to an endless band in the form of a toothed belt 14 which passes around two toothed pulleys 15.16. The motion of the guide 13 along the upper span of the belt 14 defines a traverse path which is substantially parallel with the axis 17 of the package 10. As an alternative to belt 14, an endless cable or cord may be used to minimize the inertia of the moving parts, which cable or cord may make more than one complete wrap around the surface of each pulley 15,16. Each pulley, 15, 16 is associated with a respective synchronous motor 18, 19, and each motor 18, 19 is continuously operable to rotate in its respective drive direction, in this case anti-clockwise for motor 18 and clockwise for motor 19 as shown by arrows R. The speed of the motors 18,19 may be controlled from a single line inverter (not shown) for the whole textile machine. Disposed between each motor 18, 19 and its respective pulley 15, 16 is a respective clutch 20, 21. When the apparatus is in a first operating condition clutch 20 is engaged and clutch 21 is disengaged so that pulley 15 is rotatably driven in an anti-clockwise direction, pulley 16 is freely rotatable and the yarn guide 13 travels along the traverse path towards pulley 15. A control means 22 is connected to both clutches 20, 21 and both motors 18, 19 via connections 24, 23 respectively so that when the yarn guide 13 has reached a predetermined location in the traverse path, ie the left hand end of the traverse stroke, the clutch 20 is disengaged by the control means 22 and the clutch 21 is simultaneously engaged. The apparatus is then in the second operating condition and pulley 16 is driven in a clockwise direction to move the belt 14 and yarn guide 13 towards pulley 16. Pulley 15 is at this time freely rotatable. When the yarn guide reaches a second predetermined location in the traverse path, ie the right hand end of the traverse stroke, the control means 22 disengages clutch 21 and re-engages clutch 20 via connections 24 to put the apparatus once again in the first operating condition and move the yarn guide 13 towards pulley 15. Operation of the control means 22 to change the operating condition of the apparatus, and hence the direction of travel of the yarn guide 13, may be determined by the control means 22 being responsive to the elapsed time since the previous operating condition change and the speed of rotation of the motors 18, 19 as indicated through the connections 23 from sensors 25. Alternatively the control means 22 may be responsive to a signal from a position sensor 26 detecting a marker 27 on the belt 14, or a signal from an encoder (not shown) coupled with one of the pulleys 15, 16 to determine the angular disposition thereof. The signals from sensors 25 or 26, or encoder could be fed forwardly to compensate for any delay in the clutch torque response to the applied voltage. A temperature compensation may also be built in. The clutches 20, 21 may be mechanical, in which case the connections 24 may be mechanical or electrical, or may be magnetic, piezo-electric or magnetostictive driven friction clutches in which case the connections 24 may be electrical. However in the embodiment shown in Figs 1 and 2 and described herein it is preferred that the clutches 20, 21 are electrorheological fluid or magnetorheological suspension clutches and that the connections 24 are electrical. With such clutches 20, 21 the time to engage and dizengage is considerably less than with mechanical or magnetic clutches, and wear, maintenance and lubrication are all considerably reduced. To engage a clutch 20 or 21 the control means 22 via the appropriate connection 24 causes excitation of the relevant clutch so as to cause a voltage to energize an electrorheological fluid or a magnetic field to energise a magnetorheological suspension disposed between the input and output sides of the clutch, whereby the fluid or suspension substantially instantaneously becomes effectively solid to provide a positive driving connection between the two sides of the clutch. At the same time the control means 22 cuts off the excitation of the other clutch so that substantially instantaneously the electrorheological fluid or magneto-rheological suspension in that clutch reverts to its liquid or suspension state and the driving connection between the two sides of that clutch is removed. Such rapid response is particularly advantageous for the high speed winding of textile yarns for which the present invention is particularly suited. The apparatus of the present invention has particular advantage in that the only parts thereof which reverse their direction of rotation are the pulleys 15, 16, the band 14 and the yarn guide 13, a combination of parts having very little inertia. In consequence the motors 18, 19 may be of relatively small power output compared with motors used to drive known traverse mechanisms which have much greater inertia. In addition the turn round time of the traversing parts 13,14,15 and 16 is independent of the winding speed or wind angle so that the problems of ridged or collapsed package ends are not increased when winding at lesser winding speeds or wind angles than the maximum design values. In this preferred embodiment the control means 22 is programmable so that the position of the ends of the stroke and the stroke length can be varied as the package 10 is wound in accordance with any desired programme. Also the rotational speed of the motors 18, 19 and hence the speed of traverse of the yarn guide 13 can be varied either during a traverse stroke and/or as the package 10 is wound in accordance with any desired programme. By this means patterning and ribbed or collapsed package ends can be avoided, as well as packages of any desired taper can be built. The programme preferably synchronises the stroke end position and yarn guide traverse speed variations so that the yarn tension variation throughout the package build is minimised. Alternative embodiments are shown in Figs 3 to 5 having many parts which correspond with those shown in Figs 1 and 2 and identified by corresponding reference numerals. In the embodiments of Figs 3 and 4 however, only one motor 18 is provided and the clutches 20, 21 are incorporated in the respective pulleys 15, 16. Operation of these embodiments is the same as the operation of the previously described embodiment. The difference between these two embodiments is that in the case of that of Fig 3, the input shafts of the clutches 20,21 are geared together for rotation in opposed directions, whereas in that of Fig 4, a double sided toothed belt 28 passes around pulley 29, to one side of pulley 30 and around a jockey pulley 31 to give the same opposed direction rotation. In the embodiment of Fig 5 the motor 18 drives pulley 32, belt 33, pulley 34 and the input side of the clutch 20 in one direction together with pulley 35, belt 36 and jockey pulley 37, whilst pulley 38 and the input side of clutch 21 are driven in the opposite direction. Whichever clutch 20 or 21 is energized at any given instant, that clutch provided that the single scroll cam roller 39 is driven in the corresponding rotational direction, which is reversed as that clutch is disengaged and the other clutch is engaged. The yarn 12 may be guided directly by the helical groove 40 in the cylindrical surface of the cam roller 39, or by a guide (not shown) constrained to travel in the groove 40 in a reciprocating path parallel with the package axis 17. By means of the invention a traverse mechanism is provided having the flexibility to better optimise the package build parameters than prior art traverse mechanisms, in particular the ability to maintain a constant wind angle, infinite adjustment of the taper angle, taper at one end only if desired and faster turnround at a lower traverse speeds. Other benefits provided by the traverse mechanism of the invention are low noise levels, no lubricating oil requirement and individual traverse mechanism maintenance on the textile machine.

Claims: A winding apparatus for winding a textile yarn(12) at a substantially constant speed onto a package(10); comprising yarn guide means(13,14), drive means(18.19) which is continuously operable in a driving direction(R), coupling means(20,21) comprising two clutches(20,21) each of which has an output side drivingly engaged with the yarn guide means(13,14), which coupling means(20,21) is operable in a first operating condition to engage the yarn guide means(13,14) with the drive means(18,19) whereby the yarn guide means(13,14) is driven in one direction to move the yarn(12) in a first direction along a traverse path, and then in a second operating condition to reengage the yarn guide means(13, 14) with the drive means(18,19) whereby the yarn guide means(13, 14) is driven in the opposed direction to move the yarn(12) in the reverse direction along the traverse path, at least one sensing device(25,26) operable to provide an electrical signal as the yarn(12) reaches a predetermined location on the traverse path, and control means(22) which is operable in response to the signal to change the coupling means(20,21) from one to the other of the operating conditions when the yarn(12) reaches the predetermined location, characterised in that the clutches(20,21) are driven in opposed directions and each clutch(20,21) comprises a rheological fluid which is responsive to electrical excitation wherein in one operating condition one of the clutches(20) is electrically excited to engage the yarn guide means(13,14) with the drive means(18,19) and the other clutch(21) is de-energised, and in the second operating condition the one clutch(20) is deenergised and the other clutch(21) is electrically excited to engage the yarn guide means(13,14) with the drive means(18,19), and the control means (22) is operable to excite the de-energised clutch(21,20) and de-energise the excited clutch(20,21) to change the coupling means(20,21) from one operating condition to the other. A winding apparatus according to claim 1, characterised in that the yarn guide means(13,14) comprises a yarn guide(13) mounted on an endless band(14) and in that the endless band(14) is disposed to travel around two spaced pulleys(15,16) mounted for rotation about substantially parallel axes. A winding apparatus according to claim 1, characterised in that the yarn guide means(39,40) comprises a cam roller(39) having a helical groove(40) in the cylindrical surface thereof. A winding apparatus according to any one of claims 1 to 3, characterised in that the drive means(18,19) comprises at least one motor(18) drivingly engaged with the input sides of the clutches (20,21). A winding apparatus according to any one of claims 1 to 4, characterised in that the control means(22) comprises programmable means, whereby the control means(22) is operable to vary the predetermined location on the traverse path reached by the yarn(12) when the coupling means(20,21) is changed from one operating condition to the other operating condition for successive motions of the yarn(12) along the traverse path. A winding apparatus according to claim 5, characterised in that the control means(22) is operable to vary the speed of rotation of the drive means(18,19) during each change of operating condition of the coupling means(20,21). A winding apparatus according to claim 5 or claim 6, characterised in that the control means(22) is operable to vary the speed of rotation of the drive means(18,19) between successive changes of operating condition of the coupling means(20,21). A winding apparatus according to any one of claims 1 to 7, characterised in that the clutches(20,21) each comprise an electrorheological fluid clutch(20,21), whereby the control means(22) is operable to electrically energise the fluid of one clutch(20,21) and de-energise the fluid of the other clutch(21,20) to change the coupling means(20,21) from one operating condition to the other. A winding apparatus according to any one of claims 1 to 7, characterised in that the clutches(20,21) each comprise a magneto-rheological suspension clutch(20,21), whereby the control means(22) is operable to electrically energise the suspension of one clutch(20,21) and de-energise the suspension of the other clutch(21,20) to change the coupling means(20,21) from one operating condition to the other.

Inventors: BENNETT NEALE, NAYLOR GEOFFREY, BENNETT, NEALE, NAYLOR, GEOFFREY
Applicants: RIETER SCRAGG LTD, RIETER-SCRAGG LIMITED
Application year: 1992
Main classification: B65H54
IPC codes: B65H54