Title of Invention

"A SPINDLE FOR A RING SPINNING OR A RING TWISTING MACHINE"

Abstract

A spindle (1) for a ring spinning machine or ring twisting machine comprising a zone (13) for receiving an under winding (12) in which zone a clamping means (15, 26) is arranged which is elasticaily pressed against said zone while said spindle is at standstill and which is released from said zone during rotation of said spindle due to centrifugal forces, characterized in that, said clamping means (15, 26) which surrounds a bearing shoulder (14) in said zone (13) is due to centrifugal forces during rotation of the spindle - elasticaily deformable in substantially radial direction such that it moves away from that bearing shoulder (14).

Full Text

- 2 - BACKGROUND AND SUMMARY OF THE INVENTION A spindle for a ring spinning or a ring twisting machine The present invention relates to a spindle for a ring spinning or a ring twisting machine comprising a zone for receiving underwindings in which zone a clamping means is arranged which is elastically pressed against said zone while the spinning is at a standstill and which is released from said zone during rotation of the spindle due to centrifugal forces acting on said clamping means. Underwindings are necessary on spindles in order that the spinning process can continue without an end break occuring after automatic doffing. The underwindings are generated in that at the end of a spinning process, the rotational speed is reduced and the ring rail is lowered to an area below the winder tube. In an underwinding zone of the spindle, at least one thread winding is deposited and is affixed by means of friction or the like. The fixing of the underwinding threads must be secure to such an extent that when the filled bobbin is raised from the spindle, the yarn between the underwinding and the bobbin is severed as near to the underwinding zone as possible. The underwinding thread is thereby still connected to the yarn coming from the drafting arrangement. When new winder tubes have been placed on the machine, the spinning process can be taken up again without an end break occuring in that the ring rail is raised to the area of the winder tube and then begins its traversing movements. In many practical embodiments of the spindle, the underwinding thread has to be removed from the underwinding zone after the initial operation. This is known as so-called wharve cleaning. A spindle of the above mentioned type is disclosed in EP 358 032 Al. It has the advantage in that all wharve cleaning can be omitted, as, due to its being clamped, the underwinding thread in the underwinding zone does not have to wind more than 360° around - 3 - the spindle. After the clamping effect has been lifted when the spindle starts, the underwinding thread, which has a very short length, is drawn up into the area of the winder tube and is disposed below the winding at the edge of the winder tube. The known spindle has, however, the disadvantage that it is very complicated in design and is provided with a sliding bearing in an area which is particularly susceptible to trash. The clamping means takes the form of a slide ring, which slides away in axial direction from a bearing shoulder when the spindle starts to rotate, thus releasing the underwinding thread. The sliding motion is generated by centrifugal forces, in that the slide ring comprises resilient tongues on its side facing away from the bearing shoulder, which tongues, as a result of the centrifugal forces, deform outwards and are disposed on a conical guiding surface. The guiding surface forces the slide ring to the above mentioned sliding motions directed away from the bearing shoulder. The backwards movement of the resilient tongues is supported by spring elements, which guide the slide ring to the bearing shoulder again when the spindle stops. It is an object of the present invention, while maintaining the advantage of the above mentioned spindle, to be able to omit all forms of wharve cleaning, to create a structurally uncomplicated spindle which desists from any axial sliding movements in trash-endangered areas. This object has been achieved in that the clamping means is releasable from the zone for underwindings by elastical deformation in essentially radial direction by centrifugal forces acting on said clamping means. When the spindle is not in operation, the clamping means, together with a bearing shoulder, effects an ideal clamping of the thread, without the aid of additional spring elements, for fixing the yarn during doffing. When the spindle rotates, the clamping effect is released because the diameter of the clamping - 4 - means expands as a result of the centrifugal forces, without any component sliding in axial direction on the spindle. The clamping element is released from the underwinding zone in radial direction. The underwinding yarn does not need to wind around the spindle any more than 360°, so that when the spinning process begins again, the underwinding yarn is disposed at the edge of the winder tube without any problems. The underwinding zone is thereafter free from any rest underwinding. The clamping means can, of course, be designed in a variety of ways. In one embodiment the clamping means takes the form of a finger spring, which comprises resilient tongues which can be pressed against a bearing shoulder and spread out under the effect of centrifugal forces. The tube-like area of the finger spring is affixed to the spindle and does not need to carry out any sliding movements. When the resilient tongues are raised in radial direction from the bearing shoulder, the previously clamped underwinding thread is released again. In another, particularly preferred embodiment, the clamping means takes the form of an 0-ring. The clamping means is thus not only cheap and simply made, it is easily exchangeable and operationally reliable. The diameter of the clamping means expands under the effect of centrifugal forces. This expanding property also renders its assembly unproblematic. Two 0-rings may be arranged one behind the other in axial direction, which for example have different diameters and/or different degrees of flexibility and/or different prestress. The clamping effect can thus be increased overall in the underwinding area. The purpose of the different embodiments of the two 0-rings is that the lower 0-ring opens first at the - 5 - spindle as a result of the centrifugal forces, so that an orderly winding up of the underwinding yarn is possible. A supporting ring, which rotates also, is arranged to the 0-ring, against which supporting ring the deformed 0-ring is disposed on its outer diameter when the spindle is rotating, and when the spindle is not moving, said supporting ring encircles the 0-ring at a radial distance. Thus the 0-ring, when it is raised from the bearing shoulder, can be securely fixed when the spindle is in operation. For this purpose, the bearing shoulder tapers conically towards the clamping means. This permits a particularly easy opening of the clamping means by means of its radial expansion, and the underwinding yarn is released in good time. It is practical when the bearing shoulder graduates into a ring surface adapted to the cross section of the 0-ring. This results in a good bearing surface for the 0-ring when the spindle is not in operation, which leads to a spatially exactly defined underwinding zone. The clamping means and/or the bearing shoulder can have a high friction coefficient, thereby resulting, besides the clamping effect, in an additional frictional connection. The friction coefficient can be achieved by means of either a particular material or its structure. In order to make the spindle even more operationally reliable, a simultaneously rotating fixing ring is provided upstream of the clamping means, which fixing ring is provided on its outer circumference with tooth-like yarn catching notches. Thus is the underwinding zone clearly separated from the winding area, an the underwinding yarn is prevented from loosening and being wound around the lower area of the winder tube in an uncontrolled way. - 6 - When a ring cutter is arranged to the fixing ring, the underwinding yarn can be severed during doffing at a defined place. For this purpose the ring cutter is applied downstream of the fixing ring. BRIEF DESCRIPTION OF THE DRAWINGS These and further objects, features and advantages of the present invention will become more readily apparent from the following detailed description thereof when taken in conjunction with the accompanying drawings wherein: Figure 1 is a partly cut axial view of an enlarged spindle, in which the underwinding yarn is held by the clamping means in the underwinding zone. Figure 2 is the same spindle after restarting after automatic doffing, whereby the clamping means is released from the underwinding zone. Figure 3 is a view similar to Figure 1 with another embodiment of a clamping means. DETAILED DESCRIPTION OF THE DRAWINGS Figure 1 shows the state of the spindle 1 shortly before automatic doffing, whereby the spindle 1 is already at a standstill. The spindle 1 comprises a rotating upper part 2 and a non-rotating bearing housing 3, which is stationarily fixed on a spindle rail (not shown). The shaft 4 of the spindle 1 which rotates with the upper part 2 is supported by means of a neck - 7 - bearing and a step bearing in the bearing housing 3 in a way not shown. The upper part 2 takes up a winder tube 5 by means of coupling elements (not shown), onto which winder tube 5 the spun yarn is wound into a bobbin 6. The winding process is carried out in a known way by means of a ring rail 7 which can be raised and lowered, which ring rail 7 extends over a plurality of adjacently arranged spinning stations. A spinning ring 8 is arranged to each spindle 1, on which spinning ring 8 a traveller 9 rotates, which guides the yarn to the bobbin 6 during operation. In the non-operational position shown in Figure 1, the ring rail 7 is lowered in an area below the bobbin 6. A drive wharve 10 is part of the upper part 2 of the spindle 1, against which drive wharve 10 a drive belt 11 is disposed, which is as a rule in the form of a tangential belt, which drives a plurality of adjacently arranged spindles 1. Even when the spindle 1 is braked, the drive belt 11 usually remains disposed dragging on the drive wharve 10. When the bobbin 6 is full, a so-called doffing process takes place, in which all bobbins 6 of at least one machine side are collectively lifted upwards from their spindles 1, and exchanged against empty winder tubes 5. For this purpose, the ring rail 7 is lowered onto an area below the bobbin 6, whereby a so-called underwinding zone 13 of the spindle 1 is arranged to this area. In this underwinding zone 13 an underwinding 12 is formed, which enables the spindle 1 to start again after doffing without an end break occuring. During the doffing process, the underwinding 12 is severed from the yarn of the bobbin 6, but remains connected to the yarn 23 coming from the drafting arrangement. The underwinding 12 is wound less than 360°. In the present case, the underwinding zone 13 is formed like a wedge-shaped gap. It comprises a conically downwardly tapering - 8 - bearing shoulder 14, against which a clamping means 15 is flexibly disposed when the spindle 1 is at a standstill. In this embodiment, the clamping means 15 takes the form of an 0-ring 16, whose diameter is expandable when the spindle l rotates due to the effect of the centrifugal forces. In order to ensure the reliable take-up of the o-ring 16 when the spindle 1 is at a standstill, the bearing shoulder 14 graduates into a ring surface 17 which is adapted to the circular section of the o-ring 16. In order that the best possible frictional connection for the underwinding 12 arises between the 0-ring 16 and the bearing shoulder 14, the 0-ring 16 and/or the bearing shoulder 14 have a high friction coefficient. A supporting ring 18 rotating with the spindle 1 is arranged to the 0-ring 16, which supporting ring 18 surrounds the 0-ring 16 at a radial distance when the spindle 1 is at a standstill, and against which supporting ring 18 the deformed 0-ring 16 is disposed with its outer diameter when the spindle 1 is rotating (see also Figure 2). Above the 0-ring 16, but below the winder tube 5, a so-called fixing ring 19 is arranged to the upper part 2 of the spindle 1, which fixing ring 19 is provided with tooth-like yarn catching notches 20. Thus the yarn still connected to the bobbin 6 remains at a predetermined point of the fixing ring 19, even when the underwinding 12 is wound around the underwinding zone 13. Closely beneath the fixing ring 19 a ring cutter 21 is applied, which severs the underwinding 12 from the yarn of the bobbin 6 during automatic doffing. Shortly before the formation of the underwinding 12, the yarn connected to the bobbin 6 is lowered down in several yarn loops 22 to the underwinding zone 13. As mentioned above, however, the underwinding yarn remains connected to the yarn 23 coming from the drafting arrangement. - 9 - In the embodiment shown in Figure 2, the bobbin 6 is exchanged for a winder tube 5, and the spindle 1 is once again driven to rotational movements. The ring rail 7, movable in traverse directions A and B is raised up to the area of the winder tube 5 and has already formed a few initial windings 24 on the winder tube 5. As a result of the restarting of the rotation of the spindle 1, the clamping means 15 in the form of an o-ring 16 has expanded radially. Thus the o-ring 16 is raised in radial direction from the bearing shoulder 14 and releases the underwinding 12. Underneath the initial windings 24, the released, previously clamped yarn piece 25 has wound itself around the edge of the winder tube 5. The underwinding zone 13 is thus free from any rest yarns, so that wharve cleaning can be omitted. The 0-ring 16 is disposed with its outer diameter on the supporting ring 18 rotating with the spindle 1 and is affixed thereby also during operation. The reference numbers in Figure 2 are the same as in Figure 1, so that a repeat description can be omitted. The clamping means 26 as shown in Figure 3 is somewhat more complicated in form than the 0-ring 16 as shown in Figure 1. It has, however, the advantage that an additional supporting ring can be omitted. The clamping means 26 according to Figure 3 takes the form of a so-called finger spring 27, which is connected fixedly to the upper part 2 of the spindle 1 by means of a lower tube-like area. In the area of the bearing shoulder 14, however, the clamping means 26 is provided with a plurality of resilient tongues 28, which are separated from each other by axially extending slits. These resilient tongues 28 can deform in radial direction under the - 10 - influence of centrifugal forces and thus are raised from the respective bearing shoulder 14. The resilient tongues 28 form, together with the bearing shoulder 14, an underwinding zone 13 and permit the underwinding 12 to be kept clamped when the spindle 1 is at a standstill. When the spindle 1 is rotating, however, the resilient tongues 28 are raised from the arranged bearing shoulder 14 and release the underwinding 12, so that it can be disposed on the lower edge of the winder tube 5 after automatic doffing. The reference numbers in Figure 3 are the same as those in the embodiments according to Figures 1 and 2, so that a repeat description of the remaining components is superfluous. -11-We Claim: 1. A spindle (1) for a ring spinning machine or ring twisting machine comprising a zone (13) for receiving an underwinding (12) in which zone a clamping means (15, 26) is arranged which is elastically pressed against said zone while said spindle is at standstill and,which is released from said zone during rotation of said spindle due to centrifugal forces, characterized in that, said clamping means (15, 26) which surrounds a bearing shoulder (14) in said zone (13) is elastically deforraable in substantially radial direction such that it moves away from that bearing shoulder (14) due to centrifugal forces acting on clamping means during rotation of the spindle. 2. A spindle as claimed in claim 1, wherein the diameter of said clamping means (15, 26) is expandable in said zone (13) for releasing that underwinding (12) due to centrifugal forces. 3. A spindle as claimed in claim 1 or 2, wherein that clamping means (26) takes the form of so-called finger spring (27) comprising resilient tongues (28) which are pressable against said bearing shoulder (14) and spreadable under the action of said centrifugal forces. 4. A spindle as claimed in claim 1 or 2, wherein said clamping means (15)takes the form of an 0-ring (16). 5. A spindle as claimed in claim 4, wherein a supporting ring (18) is connected to said spindle, against which ring (18) the deformed 0-ring (16) is disposed with its outer diameter when said spindle (1) is -12- rotating, said supporting ring (18) surrounds said 0-ring (16) at a radial distance when said spindle (1) is at a standstill. 6. A spindle as claimed in claim 1, wherein said bearing shoulder (14) tapers conically towards the clamping means (15, 26). 7. A spindle as claimed in claim 6, wherein said bearing shoulder (14) graduates into a ring surface (17) adapted to the circular section of the 0-ring (16). 8. A spindle as claimed in claim 6, wherein said clamping means (15, 26) and/or said bearing shoulder (14) has a high friction coefficient. 9. A spindle as claimed in claim 8, wherein a fixing ring (19) is connected to said spindle, which fixing ring is arranged upstream of said clamping means (15,26), and which fixing ring (19) is provided on its outer circumference with tooth-like yarn catching notches (20). 10.A spindle as claimed in claim 9, wherein a cutter (21) is arranged beneath said fixing ring (19). A spindle (1) for a ring spinning machine or ring twisting machine comprising a zone (13) for receiving an under winding (12) in which zone a clamping means (15, 26) is arranged which is elasticaily pressed against said zone while said spindle is at standstill and which is released from said zone during rotation of said spindle due to centrifugal forces, characterized in that, said clamping means (15, 26) which surrounds a bearing shoulder (14) in said zone (13) is due to centrifugal forces during rotation of the spindle - elasticaily deformable in substantially radial direction such that it moves away from that bearing shoulder (14).

Documents:

00868-cal-1998 abstract.pdf

00868-cal-1998 claims.pdf

00868-cal-1998 correspondence.pdf

00868-cal-1998 description(complete).pdf

00868-cal-1998 drawings.pdf

00868-cal-1998 form-1.pdf

00868-cal-1998 form-2.pdf

00868-cal-1998 form-3.pdf

00868-cal-1998 form-5.pdf

00868-cal-1998 letter patent.pdf

00868-cal-1998 p.a.pdf

00868-cal-1998 priority document others.pdf

868-CAL-1998-(14-05-2012)-CORRESPONDENCE.pdf

868-CAL-1998-(14-05-2012)-PA.pdf

868-CAL-1998-FORM-27.pdf