Drafting Device of a Textile Machine

Abstract

A drafting device of a textile machine includes a roller and an opposed counter roller, each including a roller body and an axis of rotation, wherein the axis of rotation of one or both of the roller and the counter roller is mounted only at one end thereof. The roller is movably mounted between a resting position in which the roller body of the roller and of the counter roller are not in contact, and a load position in which the roller body of the roller and of the counter roller are pressed against one another along a contact region. The roller is movable from the resting position into a load position by moving into an intermediate position wherein the axes of rotation of the roller and of counter roller are aligned such that the contact region between the roller and the counter roller is smaller than in the load position of the roller.

Claims

1-10. (canceled)

11. A drafting device of a textile machine, comprising: a roller, and an opposed counter roller, wherein a fiber sliver is guidable between the roller and counter roller; the roller and the counter roller each comprising a roller body and an axis of rotation, wherein the axis of rotation of one or both of the roller and the counter roller is mounted only at one end thereof; the roller movably mounted between a resting position in which the roller body of the roller and of the counter roller are not in contact, and a load position in which the roller body of the roller and of the counter roller are pressed against one another along a contact region; the roller movable from the resting position into a load position by moving into an intermediate position; wherein in the intermediate position, the axes of rotation of the roller and of counter roller are aligned such that the contact region between the roller body of the roller and of the counter roller is smaller in an axial direction of the axis of rotation of the roller than in the load position of the roller.

12. The drafting device according to claim 11, wherein the contact region in the intermediate position of the roller is smaller than that in the load position by a factor of at least 10.

13. The drafting device according to claim 11, wherein in the intermediate position of the roller, the contact region is adjacent a front end of the roller and the counter roller opposite the mounted end.

14. The drafting device according to claim 13, wherein the axes of rotation of the roller and of the counter roller are mounted to rotate at the mounted end by means of a bearing on the drafting device.

15. The drafting device according to claim 11, wherein the axes of rotation of the roller and of the counter roller lie in a common plane at least in the load position.

16. The drafting device according to claim 11, wherein in the intermediate position, the axes of rotation of the roller and of the counter roller form an angle () greater than 0 and up to or equal to 2.0.

17. The drafting device according to claim 16, wherein in the intermediate position, the axes of rotation of the roller and of the counter roller run skewed to one another.

18. The drafting device according to claim 11, further comprising a support, the support comprising a bearing for the mounted end of the roller, the support pivotable about a pivot axis, wherein the pivot axis of the support and the axis of rotation of one or both of the roller and the counter roller are skewed relative to one another in the intermediate position of the roller.

19. The drafting device according to claim 11, further comprising a support, the support comprising a bearing for the mounted end of the roller, the support pivotable about a pivot axis, wherein the pivot axis of the support and the axis of rotation of the counter roller are parallel to one another, and the axis of rotation of the roller and the pivot axis of the support run skewed to one another at least in the intermediate position of the roller.

20. The drafting device according to claim 11, further comprising a support, the support comprising a bearing for the mounted end of the roller, the support pivotable about a pivot axis, wherein the pivot axis of the support and the axis of rotation of the roller are parallel to one another, and the axis of rotation of the counter roller and the pivot axis of the support run skewed to one another at least in the intermediate position of the roller.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Additional advantages of the invention are described in the following embodiments, in which:

[0026] FIG. 1 shows a schematic side view of a textile machine equipped with a drafting device;

[0027] FIG. 2 shows a perspective view of a detail of a drafting device according to the invention, wherein the rollers are in their resting positions;

[0028] FIG. 3 shows the detail according to FIG. 2, wherein the rollers are in their load positions;

[0029] FIG. 4 shows the detail according to FIG. 2, wherein the rollers are in their intermediate positions; and

[0030] FIG. 5 shows a perspective view of an alternative embodiment of a detail of a drafting device according to the invention, wherein the rollers are also in their intermediate positions.

DETAILED DESCRIPTION

[0031] 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.

[0032] FIG. 1 shows an air spinning machine as an example of a textile machine 2, which may be equipped with a drafting device 1 according to the invention. However, it should be pointed out in general at this point that the drafting device 1 according to the invention may also be used in a so-called drawing frame or in other spinning machines, for example, a ring spinning machine.

[0033] The air spinning machine shown as an example in FIG. 1 is preferably used to produce so-called roving 16. Roving 16 is yarn containing a relatively small amount of cover fibers, i.e., a yarn in which the winding fibers are wrapped relatively loosely around the inner core (preferably untwisted), so that the yarn remains twistable. This is crucial if the roving 16 thus produced is or must be twisted to be processable further accordingly (wherein this drafting device 1 may also be designed according to the present invention).

[0034] The air spinning machine comprises in general a drafting device 1 with at least two roller configurations arranged one after the other in a direction of transport T of the drafting device 1, serving to twist a fiber structure 5. Each roller configuration comprises at least one roller 3 and a corresponding counter roller 4, which is mounted to be rotatable about corresponding axes of rotation 7 and between which the fiber structure 5 can be passed with clamping (for reasons of simplicity, only one of the axes of rotation 7 of the rollers 3 and one of the axes of rotation 7 of the counter rollers 4 are provided with reference numerals).

[0035] Furthermore, the air spinning machine shown here in principle comprises a spinneret 21 at a distance from the drafting device 1 and having an interior eddy chamber (known from the prior art and therefore not illustrated here) and a yarn-forming element protruding into the eddy chamber, also known from the prior art and therefore not illustrated here. The fiber sliver 5 and/or at least a portion of the fibers of the fiber sliver 5 is/are provided with a protective twist in the spinneret 21.

[0036] Likewise, the air spinning machine may have a draw-off unit 15 which preferably has two draw-off rollers 14 that can rotate about an axis of rotation 7, as well as a bobbin device 18 for the roving 16 connected downstream from the draw-off unit 15. The bobbin device in turn preferably comprises a bushing drive 19 plus at least one bushing receptacle, which is known in principle and is connected to the bushing drive 19 and to which a bushing 17 can be secured and can be induced to rotate with the help of the bushing drive 19 in order to be able to wind the roving 16, having been traversed by a traversing device 20, onto the bushing 17. The air spinning machine operates according to a special air spinning method. To form the roving 16, the fiber sliver 5 is guided in a transport direction T over an intake opening (not shown) into the eddy chamber of the spinneret 21 where it receives a protective twist, i.e., at least some of the fibers of the fiber sliver 5 are captured by an air stream generated by suitably positioned air jets. Some of the fibers are thereby pulled out of the fiber structure 5 at least some distance and wound around the tip of a yarn-forming element protruding into the eddy chamber.

[0037] Ultimately, the fibers of the fiber sliver 5 are drawn out of the eddy chamber over an intake opening of the yarn-forming element and a draw-off channel arranged inside the yarn-forming element and connected to the intake opening. Finally, the free fiber ends here are also drawn onto a spiral path in the direction of the intake opening, and in doing so, are wrapped as winding fibers around the core fibers running centrally, thereby resulting in a roving 16 having the desired protective twist.

[0038] Finally, the roving 16 has a residual drawing capacity due to the only partial twist of the fibers, this residual drawing capacity being indispensable for further processing of the roving 16 in a downstream spinning machine, for example, a ring spinning machine. However, conventional air spinning devices impart such a strong twist to the fiber sliver 5 that the necessary drawing after yarn production is no longer possible. In this case, this is also desirable because traditional air spinning machines are designed to produce a finished yarn, which should usually be characterized by a great strength.

[0039] FIG. 2 shows a detail of an drafting device 1 according to the invention, which can be used in the air spinning machine shown in FIG. 1, for example. The drafting device 1 comprises a plurality of rollers 3 and a plurality of counter rollers 4, which correspond to the rollers 3 and each of which has a roller body 6 and an axis of rotation 7, which serves to provide rotatable mounting of the respective roller body 6, wherein the axes of rotation 7 are mounted in bearings 11 (merely indicated in FIGS. 2 and 3). The bearing support of the axis of rotation 7 in the bearings 11 may be either rotatable or rotationally fixed. In the case of a rotationally fixed bearing of the axes of rotation 7 in the bearings 11, the roller body 6 is held rotatably on the axis of rotation 7. Accordingly, with a rotatable bearing support of the axis of rotation 7 in the bearing 11, a rotationally fixed restraint of the roller body 6 on the axis of rotation 7 is to be provided.

[0040] Furthermore, FIG. 2 shows, among other things, that the rollers 3 are preferably mounted in a support 12 and that the counter rollers 4 are mounted in a corresponding counter support 9. The bearing support here is unilateral, i.e., the respective axes of rotation 7 each extend between only one of the two front ends 10 of the corresponding roller bodies 6 and the respective support 12 and/or counter support 9 (of course, each roller 3 or group of rollers 3 may be supported in a separate support 12 in order to be able to adjust the mutual spacings of the rollers 3; the same thing also applies according to the counter rollers and their counter supports 9).

[0041] The core of the invention is derived from a combined view of FIGS. 2 to 4. First, FIG. 2 shows the condition of the drafting device 1, in which the rollers 3 are in their resting position, i.e., the roller bodies 6 of the roller 3 and the counter roller 4 are not in contact. The rollers 3 preferably assume this position while the drafting device 1 is stopped, such that the rollers 3 and/or counter rollers 4 are not driven and the fiber sliver 5 has been and/or is to be removed from the drafting device 1.

[0042] Before or shortly after the drafting device 1 is or has been charged in a transport direction T with a fiber sliver 5, the rollers 3 are moved into their load position shown in FIG. 3, wherein this can take place, for example, by pivoting the support 12 about a pivot axis 13 (the pivot axis 13 is shown only in FIG. 3).

[0043] With traditional drafting devices 1, there is the disadvantage here that the mutual pressing force of the individual roller bodies 6 pressed against one another is not constant along their contact region 8 (which is linear in FIG. 3) because the individual bearings 11 have a certain play and the axes of rotation 7 usually have at least minimal sagging. A fiber sliver 5 passed between the roller bodies 6 is therefore not uniformly subjected to load over its width running perpendicular to the transport direction T so that uneven drawing of the individual segments of the fiber sliver 5 occurs.

[0044] To counteract this disadvantage, it is now proposed within the scope of the present invention that the axes of rotation 7 of the rollers 3 designed according to the invention shall have an orientation in an intermediate position as illustrated in FIG. 4, which results in the roller bodies 6 of the roller 3 having a joint contact region 8 and the counter roller 4 having a common contact area 8, which is smaller as seen in the axial direction of the axis of rotation 7 of the roller 3 than in the load position illustrated in FIG. 3.

[0045] As is apparent from FIG. 4 in this context, the roller bodies 6 of the roller 3 and the corresponding counter roller 4 preferably have only an essentially dot-shaped contact region 8 in the intermediate position wherein this can be implemented by the fact that the axes of rotation 7 of the roller 3 and counter roller 4 form an angle in the aforementioned intermediate position, the size of this angle being different than 0 (reference is made to the general description with regard to advantageous angle sizes).

[0046] If rollers 3 mounted in this way are moved out of their intermediate position and into their load position illustrated in FIG. 3 by pivoting the support 12, then any play in the bearings 11 and/or a slight curving of the individual axes of rotation 7 are balanced in such a way that the pressing force is constant over the entire contact region 8 between the roller 3 and the counter roller 4 (ideal case). A fiber sliver 5 guided with clamping between the corresponding roller bodies 6 is uniformly loaded here over its width so that the fiber sliver 5 can be drawn in a particularly homogeneous manner.

[0047] Although FIG. 4 illustrates an approach in which the axes of rotation 7 of the rollers 3 are mounted obliquely in the support 12, and the support 12 can be pivoted about a pivot axis 13 running parallel to the axes of rotation 7 of the counter rollers 4, FIG. 5 shows an alternative embodiment which is characterized in that the axes of rotation 7 of the rollers 3 are aligned parallel with the pivot axis 13 of the support 12. In this case, both the pivot axis 13 of the support and the axes of rotation 7 of the rollers 3 form an angle (shown in an exaggerated size in FIG. 5) with the axes of rotation 7 of the counter rollers 4 in a front view of the drafting device 1, the size of said angle differing from 0, as seen in the intermediate position in FIG. 5. Thus, again in this variant, it is ensured that the roller bodies 6 of the rollers 3 and the counter rollers 4 each have only an essentially dot-shaped contact region 8 when the rollers 3 are in their intermediate position.

[0048] The present invention is not limited to the embodiments illustrated and described here. Modifications within the scope of the patent claims are also possible as is any combination of the features described here, even if they are illustrated in different embodiments and described in different portions of the description and/or claims.

LIST OF REFERENCE NUMERALS

[0049] 1 Drafting device [0050] 2 Textile machine [0051] 3 Roller [0052] 4 Counter roller [0053] 5 Fiber sliver [0054] 6 Roller body [0055] 7 Axis of rotation [0056] 8 Contact region [0057] 9 Counter support [0058] 10 Front end [0059] 11 Bearing [0060] 12 Support [0061] 13 Pivot axis of the support [0062] 14 Draw-off roller [0063] 15 Draw-off unit [0064] 16 Roving [0065] 17 Bushing [0066] 18 Bobbin device [0067] 19 Bushing drive [0068] 20 Traversing device [0069] 21 Spinneret [0070] Angle formed by the axes of rotation of the roller and the counter roller in the intermediate position [0071] T Direction of transport