False twist device for an open-end spinning device

Abstract

A false twist device for an open-end spinning device to introduce a false twist in a yarn has a largely tubular carcass and several false twist edges arranged behind one another in the yarn draw-off direction and inclined by an angle in the carcass with regard to the yarn draw-off direction. The false twist edges protrude in such a way into the interior of the tubular carcass that the yarn experiences a deflection on each one of the false twist edges. The several false twist edges are arranged offset in such a way in the carcass in circumferential direction that the yarn simultaneously experiences a spatial deflection compared to its regular yarn draw-off direction through the successive deflections on the several false twist edges.

Claims

1. A false twist device for an open-end spinning device to introduce a false twist in a yarn produced in the open-end spinning device, the false twist device comprising: a tubular carcass; a plurality of false twist edges arranged behind one another in a yarn draw-off direction through the device, each of the false twist edges inclined at an angle () in the carcass relative to the yarn draw-off direction; the plurality of false twist edges configured in an interior of the carcass such that each individual false twist edge imparts a deflection to a yarn drawn through the carcass; and the plurality of false twist edges offset in a circumferential direction in the carcass such that the yarn drawn through the carcass is also simultaneously subjected to a spatial, helical, deflection through the successive deflections on the false twist edges.

2. The false twist device according to claim 1, wherein the false twist edges have a height within the carcass greater than one-half of an inner diameter of the carcass.

3. The false twist device according to claim 1, comprising at least three of the false twist edges.

4. The false twist device according to claim 3, wherein three of the false twist edges are arranged circumferentially offset to one another by a circumferential offset angle 120.

5. The false twist device according to claim 1, wherein the false twist edges are defined as webs that are inserted into the carcass.

6. The false twist device according to claim 1, wherein the device is configured as a detachable insert that can be inserted in the open-end spinning device.

7. The false twist device according to claim 1, further comprising a plurality of cylindrical or semi-cylindrical sections arranged behind one another in the yarn draw-off direction, wherein one of the false twist edges in provided in each respective one of the sections.

8. The false twist device according to claim 7, wherein each section comprises at least one positioning element that positions the section in a defined circumferential offset angle relative to an adjacent section.

9. The false twist device according to claim 7, wherein the sections are made of ceramic, metal or plastic.

10. The false twist device according to claim 1, wherein the device is configured as a detachable insert that can be inserted in the open-end spinning device, and further comprising a housing that surrounds the insert.

11. An open-end spinning device of a rotor spinning machine, comprising: a yarn draw-off nozzle; a false twist device arranged downstream from the yarn draw-off nozzle in a yarn draw-off direction; the false twist device further comprising: a tubular carcass; a plurality of false twist edges arranged behind one another in a yarn draw-off direction through the device, each of the false twist edges inclined at an angle () in the carcass relative to the yarn draw-off direction; the plurality of false twist edges configured in an interior of the carcass such that each individual false twist edge imparts a deflection to a yarn drawn through the carcass; and the plurality of false twist edges offset in a circumferential direction in the carcass such that the yarn drawn through the carcass is also simultaneously subjected to a spatial, helical, deflection through the successive deflections on the false twist edges.

12. The open-end spinning device according to claim 11, wherein the false twist device is arranged in the yarn draw-off direction directly behind the yarn draw-off nozzle.

13. The open-end spinning device according to claim 12, the yarn draw-off nozzle and the false twist device have a common, detachable housing arranged in the open-end spinning device.

14. The open-end spinning device according to claim 11, further comprising a draw-off tube arranged downstream from the false twist device, the draw-off tube defining an additional false twist edge for the yarn.

15. A method for introducing a false twist in a yarn generated in an open-end spinning device of a rotor spinning machine, comprising: drawing the yarn off through a yarn draw-off nozzle; pulling the yarn through a plurality of false twist edges in a false twist device arranged downstream from the yarn draw-off nozzle, whereby a false twist is imparted to the yarn; and imparting a spatial, helical deflection to the yarn with the false twist edges to provide an additional component of the false twist imparted to the yarn.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Additional advantages of the invention are described by means of the embodiments shown below, which show:

(2) FIG. 1 an overview of a working position of a rotor spinning machine in a schematic lateral view,

(3) FIG. 2 a schematic cross-sectional view of an open-end spinning device showing a yarn draw-off nozzle and a false twist device,

(4) FIG. 3 a schematic diagram of a spatial deflection of the yarn on false twist edges arranged offset to one another in circumferential direction,

(5) FIG. 4 a view of a false twist device executed as insert with several sections,

(6) FIG. 5 a false twist device made up of several sections with a yarn draw-off nozzle in a joint housing, and

(7) FIG. 6 a detailed view of an individual section of a false twist device executed as an insert.

DETAILED DESCRIPTION

(8) Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.

(9) FIG. 1 shows a schematic lateral view of an open-end spinning device 1 of a rotor spinning machine 2. The rotor spinning machine 2 includes here many working positions arranged beside one another in longitudinal direction of the spinning machine 2. Here, each working position includes typically a feeding device 8, which feeds fiber material 6 to the open-end spinning device 1 through an opening device 9, which opens the fiber material 6 into individual fibers. In this process, the fiber material 6 is stored in storage containers 4 on the rotor spinning machine 2. The fiber material 6 opened into individual fibers is finally fed to the spinning rotor 3 of the open-end spinning device 1 via a fiber feeding duct 5 (see FIG. 2). The yarn 7 produced in the spinning rotor 3 is finally drawn off from the open-end spinning device 1 via a draw-off device 10 and wound up onto a bobbin 12 by means of a winding device 11.

(10) The open-end spinning device 1 is shown schematically in FIG. 2 in a cutaway lateral view. The open-end spinning device 1 encompasses here a spinning rotor 3, whose rotor cup is arranged in a rotor housing 13. The rotor housing 13 is typically impinged with negative spinning pressure and closed by a detachable lid 14. A seal 15 is provided between the rotor housing 13 and the lid 14 to maintain the negative spinning pressure prevalent in the rotor housing 13. Furthermore, the fiber feeding duct 5 (already described in FIG. 1) is arranged in the lid 14. One end of the duct is connected to the opening device 9 and its other end protrudes into the spinning rotor 3 so the fiber material 6 can be fed to the inner wall of the spinning rotor 3.

(11) To produce the yarn, the individual fibers fed into the spinning rotor 3 are transported to the rotor groove of the spinning rotor 3 owing to the centrifugal force. There, they make contact with a rotating yarn leg 7a of the already produced yarn 7 and are incorporated into the yarn end 7a due to the rotation of the spinning rotor 3. To improve fiber incorporation, it has proven advantageous to increase yarn twisting in the rotating yarn leg 7a located between the yarn draw-off nozzle 16 and the rotor groove by means of a false twist device 17. The yarn 7 produced in the spinning rotor 3 is finally drawn off through the draw-off device 10 via a yarn draw-off nozzle 16 arranged in the lid 14 too and through the false twist device 17 arranged downstream from the yarn draw-off nozzle 16. According to the present description, a small draw-off tube 18 having additional false twist edges 19 is furthermore arranged after the false twist device 17. This is not absolutely necessary, however. Likewise, the yarn 7 can be directly fed to the draw-off device 10 after it comes out of the false twist device 17 without another deflection and without passing through another twist element.

(12) In conventional false twist devices 17, the yarn 7 is pulled in the yarn draw-off direction G over several false twist edges 19 arranged in succession. In this process, the flattening out of the yarn cross section on the false twist edges causes the yarn 7 twists to be pushed all the way through the yarn draw-off nozzle 16 back to the rotating yarn leg 7a or to the rotor groove.

(13) The present false twist device 17 provides the false twist edges 19 to be arranged not only behind one another in yarn draw-off direction G, but at the same time offset in the circumferential direction in the carcass 20 of the false twist device 17. This makes it possible to achieve a spatial deflection of the yarn 7, whichin addition to the twist displacement by the false twist edges 19gives the yarn an additional twist that is propagated, in turn, as a false twist into the rotor groove area.

(14) The basic drawing of FIG. 3 shows such a false twist device 17. Here, the regular yarn draw-off direction G is indicated by a dot and dash line in FIG. 3. In the present false twist device 17, the false twist edges 19 are not only arranged offset in the carcass 20 behind one another in yarn draw-off direction G, but at the same time also in circumferential direction of the false twist device 17 or the carcass 20 of the false twist device 17 and protrude into the yarn-guiding interior cross-section or interior 21 of the false twist device 17, so that the yarn 7 experiences a spatial deflection compared to the regular yarn draw-off direction G. The thread path of the deflected yarn 7 is shown here by a dotted line.

(15) In this process, it is evident that on each one of the false twist edges 19, the yarn 7 is deflected from the regular yarn draw-off direction G by an amount e. Through the spiral staircase-like arrangement of the false twist edges 19, the yarn 7 experiences a helicoidal deflection that imparts the yarn 7 an additional torsion momentum. Here, it is particularly advantageous ifas described abovethe false twist edges 19 are arranged offset to one another around a uniform offset angle in circumferential direction. Thus, as described above, three of the false twist edges 19 can be twisted in each case by 120 but it is not absolutely necessary to distribute false twist edges 19 on exactly 360 of the circumferential direction. The desired spatial deflection of the yarn 7 can also be achieved with several false twist edges 19 or with fewer false twist edges 19 too, although it is not absolutely necessary to arrange the false twist edges 19 at regular distances from one another with regard to the yarn draw-off direction G or with regular offset angles with regard to the circumferential direction. In this case, the spatial deflection or helical path of the yarn resulting from the arrangement of the false twist edges 19 can be oriented both to the right and to the left with regard to the yarn draw-off direction G. In the case of a z-twist in the yarn, the helical line turns to the right in thread draw-off direction.

(16) FIG. 4 shows a first embodiment of a false twist device 17 executed as an insert 23 consisting of several sections 22. The false twist device 17 or the insert 23 consists here of three largely semi-cylindrical sections 22, whereby a false twist edge 19 has been arranged in each one of the sections 22. The false twist edges 19 have preferably an angle of 40 to 60 in the yarn draw-off direction G. This inclination of the false twist edges 19, in turn, allows the further increase of the false twist that can be introduced. The individual sections 22 are now twisted in each case towards one another by an offset angle and in yarn draw-off direction G behind one another and put together to the insert 23. Here, one or several projections 24 are preferably arranged in each one of the sections 22 and they act together, in turn, with the corresponding recesses 25 of contiguous sections 22. Thus, the projections 24 and recesses 25 constitute positioning elements used to position the individual sections 22 together in circumferential direction. As a result of this, the individual sections 22 of the false twist device 17 are joined together form-fittingly in circumferential direction and secured against twisting.

(17) FIG. 6 shows a detailed view of such an individual section 22 with a false twist edge 19. As can be seen in FIG. 6, owing to the shape of a semi-cylindrical shell with the false twist edge 19 arranged therein, such a section 22 can be manufactured economically as an injection molded part, as the shape given to the part allows easy deformation.

(18) Such a false twist device 17 made up of individual sections 22 has preferably a housing 26 surrounding the insert 23 or individual sections 22 of the insert 23. It is also possible here to insert the insert 23 with its surrounding housing 26 into the open-end spinning device. However, it is likewise conceivable to insert the insert 23 or the individual sections 22 of the insert 23 directly into a draw-off duct of the open-end spinning device 1, which can be executed in the lid element 14 (see FIG. 2).

(19) According to another embodiment (see FIG. 5), however, the false twist device 17 and the yarn draw-off nozzle 16 are arranged in one joint housing 26. In this case, the false twist device 17 is thus arranged directly downstream from the yarn draw-off nozzle 16, so that the torsion momentum generated by the false twist device 17 supports directly a false twist already generated by the yarn draw-off nozzle 16. In the process, the individual sections 22 of the insert 23 can be fastened additionally together (e.g. glued to one another). However, if a housing 26 surrounding the individual sections 22 is provided, then this is not absolutely necessary because a fixation of both of the individual sections 22 and of a one-part insert 23 can also be accomplished with the housing and/or the yarn draw-off nozzle 16, on which the insert 23 can find support in yarn draw-off direction G.

(20) As can be seen in FIG. 5, the false twist edges 19 have a certain height H here, greater than one-half of the interior diameter I of the carcass 20, so that a good spatial deflection of the yarn 7 can be generated as a result of that. Such a structural unit from a yarn draw-off nozzle 16 and a false twist device 17 can easily be removed from the open-end spinning device 1, and the yarn draw-off nozzle 16 and the false twist edges 19 or the insert 23 can be easily replaced.

(21) Deviating from the diagram shown in FIGS. 4-6, however, it is also possible to manufacture the false twist edges 19 as webs and insert the false twist device 17 into the carcass 20, either by gluing or clipping it on, for example.

(22) The invention is not restricted to the embodiments shown. Thus, one-piece inserts 23 can also be especially provided instead of an insert 23 made up of several sections 22. Likewise, the false twist device 17 could have a cylindrical carcass 20, into whose cylindrical area false twist edges 19 executed as webs or pins could be inserted from the side. Moreover, it is not absolutely necessary to arrange the false twist device 17 (as shown in FIGS. 2 and 5, for example), coaxially to the yarn draw-off nozzle 16 and directly downstream from the yarn draw-off nozzle 16. The false twist device 17 can likewise be provided in an angle to the yarn draw-off nozzle 16. Furthermore, regarding the number and arrangement of the false twist edges 19 within the false twist device 17, numerous variations are possible. Thus, for example, even less than three false twist edges 19 can be provided in the false twist device 17, and the false twist device 17 can also have an inlet or outlet area that constitutes an additional yarn deflection. Further variations and combinations also fall under the invention as part of the patent claims.

LIST OF REFERENCE CHARACTERS

(23) 1 Open-end spinning device 2 Rotor spinning machine 3 Spinning rotor 4 Storage container 5 Fiber feeding duct 6 Fiber material 7 Yarn 7a rotating yarn leg 8 Feeding device 9 Opening device 10 Draw-off device 11 Winding device 12 Bobbin 13 Rotor housing 14 Lid of the rotor housing 15 Seal of the rotor housing 16 Yarn draw-off nozzle 17 False twist device 18 Small draw-off tube 19 False twist edge 20 Carcass 21 Interior 22 Section 23 Insert 24 Projection 25 Recesses 26 Housing a Inclination angle of the false twist edges e Deflection of the yarns on the false twist edge G Yarn draw-off direction H Height of the false twist edges I Inner diameter of the carcass