DRAFTING SYSTEM FOR A TEXTILE MACHINE

Abstract

In a drafting system (1) for a textile machine, in particular an air-spinning machine, for drafting a strand-shaped fibre band fed to the drafting system, having a plurality of roller pairs arranged in succession in a running direction (A) of the fibre band and each having a top roller (3) and a bottom roller (4), and a weighting device for applying a load to the top roller (3) of the plurality of roller pairs; wherein the respective bottom roller (4) is mounted and held in a housing (2) of the drafting system (1), wherein the respective top roller (3) is mounted and held in the housing (2) of the drafting system (1) by means of a top roller carrier (30) which can be pivoted about a rotary axis.

Claims

1. A drafting system (1) for a textile machine, in particular an air-spinning machine, for drawing a strand-shaped fibre band fed to the drafting system, comprising: a plurality of roller pairs arranged in succession in a running direction (A) of the fibre band, each comprising: a top roller (3); a bottom roller (4); and a weighting device configured to apply a load to the top roller (3) of the plurality of roller pairs wherein: the bottom roller (4) is mounted and held in a housing (2) of the drafting system (1), and the top roller (3) is mounted and held in the housing (2) of the drafting system (1) via a top roller carrier (30) configured to be pivoted about a rotary axis; and a swivelling weighting arm (20) configured to be brought into an open position and a closed position, wherein the weighting arm (20) comprises an individually adjustable weighting device (40) for each roller pair of the plurality of roller pairs, configured to apply a load to the pivotable top roller carrier (30) in a weighting position when the weighting arm (20) is closed.

2. The drafting system according to claim 1, wherein the bottom rollers (4) are each mounted on a bottom roller carrier (2a) fixed in the housing (2).

3. The drafting system according to claim 2, wherein the bottom roller carrier (2a) is configured to be: displaced along the running direction (A) of the fibre band: and fixed in a desired position.

4. The drafting system according to claim 2, wherein the pivotable top roller carrier (30) is connected to the bottom roller carrier (2) such that it can pivot about a rotary axis (31) of the top roller carrier (30).

5. The drafting system according to claim 1, wherein the rotary axis (31) of the top roller carrier (30) is arranged downstream or upstream of the roller pairs in the running direction (A) of the fibre band, such that the top roller carrier (30) can be swung out in the running direction (A) or against the running direction (A).

6. The drafting system according to claim 1, further comprising a top roller axis (31) of the top roller (3), mounted at both ends in a top roller yoke (32) attached to the top roller carrier (30).

7. The drafting system according to claim 6, wherein the top roller axis (31) of the top roller (3) is secured in the top roller yoke (32) via a top roller safety device (33).

8. The drafting system according to claim 6, wherein the top roller yoke (32) is attached to the top roller carrier (30) such that it can be displaced along the running direction (A) of the fibre band, so that the top roller (3) can be brought into a desired position relative to the bottom roller (4) and fixed in place.

9. The drafting system according to claim 1, wherein the weighting device (40) comprises a load element (41) wherein the load element comprises a pneumatic or spring-loaded load element.

10. The drafting system according to claim 9, wherein the weighting device (40) or the load element (41) is configured to be moved and attached to the weighting arm (20) in various positions along the running direction (A) of the fibre band so that a point of application of the load by the weighting device (40) is capable of being brought into a desired position of the top roller carrier (30) and fixed in place.

11. The drafting system according to claim 1, wherein: the weighting device (40) comprises a convex load head (42), and the load head (42) is capable of being moved and attached to the top roller carrier (30) in various positions along the running direction (A) of the fibre band, so that a point of application of the load by the weighting device is capable of being brought into a desired position relative to the top roller carrier (30) and fixed in place.

12. The drafting system according to claim 1, wherein the weighting arm (20) is configured to be locked in a closed position without play.

13. The drafting system according to claim 1, wherein the weighting device (40) is configured to be brought into a weighting position or a non-weighting position when the weighting arm (20) is in the closed position.

14. The drafting system according to claim 11, wherein: the weighting device (40) comprises one or more weighting devices (40), and wherein the one or more weighting devices (40) are configured to be moved, individually or in a group, into the weighting position or the non-weighting position.

15. The drafting system according to claim 1, wherein a point of application of the load by the weighting device (40) is offset with respect to a middle of the top roller (3) along a top roller axis (34).

16. The drafting system according to claim 7, wherein the top roller safety device (33) is configured to be released by hand.

17. The drafting system according to claim 9, wherein the pneumatic or spring-loaded load element is selected from the group consisting of: a pneumatic cylinder; an air spring; a coil spring; a leaf spring; a diaphragm cylinder; a diaphragm compression element; and a bellows.

Description

BRIEF EXPLANATION OF THE FIGURES

[0028] The present invention should be explained in more detail below by means of embodiment examples in connection with the drawing(s). In the drawings:

[0029] FIG. 1 shows a schematic side view of a drafting system;

[0030] FIG. 2 shows a detail of the drafting system from FIG. 1;

[0031] FIG. 3 shows a sectional view of a top roller suspension with weighting device;

[0032] FIG. 4 shows a section of the drafting system with a weighting device with a movable load head;

[0033] FIG. 5 shows, under (a), a weighting device with movable load head and, under (b), a detailed view from FIG. 5(a);

[0034] FIG. 6 shows a top view of a load head;

[0035] FIG. 7 shows a weighting device with a load element for several roller pairs.

WAYS TO IMPLEMENT THE PRESENT INVENTION

[0036] FIG. 1 shows a schematic side view of an embodiment of a drafting system for a textile machine. The drafting system 1 has a plurality of roller pairs and is particularly suitable for an air-spinning machine, in which precise positioning and loading of the roller pairs is essential due to the high spinning speeds. FIG. 2 shows a detail of FIG. 1 with a roller pair.

[0037] The drafting system 1 has several roller pairs arranged in succession in a running direction A of a fibre band, each with a top roller 3 and a bottom roller 4. Furthermore, the drafting system can have aprons known from the prior art, which are not shown here. Each bottom roller 4 can be mounted in a manner of prior art on a bearing block or a bottom roller carrier 2a in the drafting system housing 2. As a rule, their positioning relative to the running direction A can be adjusted and fixed in place.

[0038] Each top roller 3 is attached to a top roller carrier 30 which can be pivoted about a rotary axis 31. The rotary axis 31 runs parallel to the rotary axes of the rollers. The pivotable top roller carrier 30 is connected to the bearing block or bottom roller carrier 2a of the bottom roller 4 or the drafting system housing. For the mounting of the top roller 3, the top roller carrier 30 can have a top roller yoke 32, which is connected to the top roller carrier 30. This connection is configured in such a way that the top roller yoke 32 can be moved relative to the top roller carrier 30 in the running direction A of the drafting system and fixed in the desired position. This allows precise positioning of the top roller 3 in relation to the bottom roller 4. In particular, it is possible in this way to adjust an upstream or downstream protrusion of the top roller 3 relative to the bottom roller 4. The displaceability is indicated by arrow C in FIG. 2 and FIG. 4.

[0039] The top roller yoke 32 applies a load on the top roller axis 34 on both sides so that an even contact force of the two rollers is achieved.

[0040] The rotary axis 31 of the top roller carrier 30 can also be located further down than shown in the figures and closer to the rotary axis of the top roller 3. An angled or curved top roller carrier can also be used instead of the straight top roller carrier 30 shown.

[0041] In order to hold the top roller 4 in the mounting of the top roller yoke 32, in particular when the top roller carrier 31 pivots out, a top roller safety device 33, e.g. in the form of a leaf spring, is provided in the embodiment shown, which acts on the top roller axis 34. This can be loosened in a simple manner by hand so that the top roller axis 34 with the top roller 4 can be easily removed from the mounting on the top roller yoke 32. Other embodiments of the top roller safety device 33 are also possible.

[0042] A weighting arm 20 is arranged above the top rollers 4, which is pivotably connected to the drafting system housing 2 via a rotary axis 21. The rotary axis 21 also runs parallel to the rotary axes of the rollers. The weighting arm 40 can be moved back and forth between an open position and a closed position. In the closed position, the weighting arm 40 preferably rests against a fixed stop 24 and can be secured in position by means of a locking mechanism 23 so that it assumes a backlash-free and precisely defined position in the closed position.

[0043] A weighting device 40 is arranged on the weighting arm 20 for each roller pair. The weighting device 40 is used to apply a load to a top roller 3 in each case. For this purpose, the weighting device 40 has a load element 41 and a convex load head 42. The load element can be configured as a pneumatic or spring-loaded load element (for example, a pneumatic cylinder, air spring, coil spring, leaf spring, diaphragm cylinder, diaphragm pressure element or bellows). The load head 42 provides a precisely positionable point of application of the load by the weighting device 40 to the top roller carrier 30. The load can be finely adjusted by moving the point of application.

[0044] In the embodiment shown, the weighting device 40 or the load element 41 is held in the weighting arm 20 so that it can be moved and fixed in a desired position relative to the top roller carrier 30 in the running direction A of the drafting system. With this displaceability, the point of application of the load element 41 relative to the top roller carrier 30 or the top roller 3 can be adjusted in order to achieve fine adjustment of the contact pressure of the top roller 3 on the bottom roller 3 via the lever effect of the top roller carrier 30. The displaceability is indicated by arrow B in FIG. 2.

[0045] FIG. 3 shows a sectional view of a top roller suspension with weighting device 40 as described above. The top roller axis 34 of the top roller 4 is mounted in the top roller yoke 32. The top roller yoke 32 is attached to the top roller carrier 30 so that it can be moved and fixed in place. In the embodiment shown, a protrusion of the top roller yoke 32 is guided in a guide of the top roller carrier 30. The top roller yoke 32 can be fixed with a screw. In the same way, the weighting device 40 can be connected to the weighting arm 20.

[0046] The point of application of the load by the weighting device 40 is arranged asymmetrically with respect to the middle of the top roller 3 and offset to the same side along the top roller axis 34 in all roller pairs, so that the visibility and operability of the drafting system from one side is increased.

[0047] FIG. 4 shows a section of the drafting system with a further embodiment of a weighting device. In contrast to the weighting device of FIG. 2, the convex load head 42 can be fastened to the top roller carrier 31 in various positions along the running direction A of the drafting system and contacts the load element 41 with the convex side. The fine adjustment described above can be achieved by moving (arrow D) the load head 42. This embodiment has the advantage that when the bottom roller carrier 2a is displaced, the point of application of the load by the weighting device 40 is not displaced relative to the top roller carrier 31, and a possible new fine adjustment is not necessary.

[0048] FIG. 5(a) shows an embodiment of the weighting device with a diaphragm cylinder as load element 41. Furthermore, a convex load head 42 is shown, which can be attached to the top roller carrier 30 at various positions. FIG. 5(b) shows a larger detailed view from FIG. 5(a).

[0049] In the variant, the load head 42 has two pins 43 on an underside opposite the convex side, which can be inserted into double bores 35 in the top roller carrier 30. In order to position the load head 42 at different locations, the top roller carrier 30 has a number of evenly spaced double bores 35 (steps). A top view of the underside of the load head is shown in FIG. 6.

[0050] The pins 43 are offset ¼ the distance of the double bores 35 from the axis of the load head 42. By inserting the load head 42 alternately rotated 180° into the double bores 35, the number of steps can be doubled in relation to the number of double bores 35. Sloped surfaces can be formed on a base of the load head 42 as a visual check of the orientation of the load head 42.

[0051] The convex side of the load head 42 is spherical, dome-shaped or mushroom-shaped, so that a diaphragm of the diaphragm cylinder is entirely without a hard surface. The substructure of the load head or the bottom roller carrier 2a can be moved slightly without having to move the diaphragm cylinder as well.

[0052] The pins can also be rectangular or oval in shape, so that even with only one pin, independent twisting of the load head 42 is prevented.

[0053] To achieve a higher load, the diaphragm cylinder can be oval or elliptical in shape.

[0054] In contrast to FIG. 5, FIG. 7 shows an embodiment of the weighting device 40 with a diaphragm element as load element 41, which extends over several roller pairs. The diaphragm element can be tubular or sausage-shaped and acts on the load head 42 from several roller pairs. In this case, the force application can be individually adjusted via the positioning of the load head 42 relative to the top roller carrier 30.

TABLE-US-00001 List of reference signs 1 Drafting system 2 Housing of the drafting system (supporting structure) 2a Bottom roller carrier 3 Top roller 4 Bottom roller 20 Weighting arm 21 Rotary axis weighting arm 23 Locking mechanism of the weighting arm 24 Stop 30 Top roller carrier 31 Rotary axis top roller carrier 32 Top roller yoke 33 Top roller safety device 34 Top roller axis 35 Double bore 40 Weighting device 41 Load element 42 Convex load head 43 Pin A Fibre running direction B Mobility of load element C Mobility of top roller yoke D Mobility of load head