Traversing unit, method for operating a traversing unit, and workstation comprising a traversing unit

Abstract

A traversing unit for traversing a yarn with respect to a pair of delivery rollers of a workstation of a textile machine includes a yarn-guiding unit, a single traversing drive configured with the yarn-guiding unit, and a conversion element configured with the single traversing drive such a rotational movement () of the single traversing drive is converted into a linear, reciprocating movement of the yarn-guiding unit. The single traversing drive is a rotating motor. A sensor is disposed to detect at least a middle position of the yarn-guiding unit.

Claims

1. A traversing unit for traversing a yarn with respect to a pair of delivery rollers of a workstation of a textile machine, comprising: a yarn-guiding unit; a single traversing drive at the workstation configured with the yarn-guiding unit, wherein each workstation of the textile machine has a respective single traversing drive; a conversion element configured with the single traversing drive such that a rotational movement (w) of the single traversing drive is converted into a linear, reciprocating movement of the yarn-guiding unit; the single traversing drive comprising a rotating motor; and a sensor disposed at the workstation to detect at least a middle position (M) of the yarn-guiding unit.

2. The traversing unit as in claim 1, wherein the conversion element comprises an eccentric element that interacts with a guide element provided on the yarn-guiding unit.

3. The traversing unit as in claim 2, wherein the guide element comprises two guide edges between which the eccentric element is guided.

4. The traversing unit as in claim 1, wherein the sensor is situated adjacent to the conversion element.

5. The traversing unit as in claim 4, wherein the sensor comprises a Hall sensor and the conversion element comprises a magnetic element.

6. A traversing unit for traversing a yarn with respect to a pair of delivery rollers of a workstation of a textile machine, comprising: a yarn-guiding unit; a single traversing drive configured with the yarn-guiding unit; a conversion element configured with the single traversing drive such that a rotational movement (w) of the single traversing drive is converted into a linear, reciprocating movement of the yarn-guiding unit; the single traversing drive comprising a rotating motor; a sensor disposed to detect at least a middle position (M) of the yarn-guiding unit; and wherein the yarn-guiding unit comprises one or both of a cutting unit and a blowing unit, with the aid of which the yarn can be cut in two or a yarn end can be blown into the workstation.

7. The traversing unit as in claim 1, wherein the yarn-guiding unit comprises a measuring unit, with the aid of which a condition of the yarn can be detected.

8. The traversing unit as in claim 1, wherein the single traversing drive is fixedly situated at the workstation, and the conversion element comprises an eccentric element that interacts with a guide element provided on the yarn-guiding unit, the guide element displaceable with respect to the workstation with the aid of the eccentric element.

9. The traversing unit as in claim 1, wherein one or both of the sensor and the conversion element are situated on the traversing unit such that an aligned position of the yarn-guiding unit with respect to a draw-off tube of the workstation is detectable.

10. A workstation of a textile machine, comprising a traversing unit according to claim 1.

11. A method for operating a traversing unit of a workstation of a textile machine, comprising: guiding a moving yarn in a yarn-guiding unit of the traversing unit and moving the yarn-guiding unit linearly back and forth with a single traversing drive at the workstation and a conversion element to traverse the yarn with respect to a pair of delivery rollers, wherein each workstation of the textile machine has a respective single traversing drive; operating the single traversing drive as a rotating motor; and detecting a middle position (M) of the yarn-guiding unit with the aid of a sensor.

12. A method for operating a traversing unit of a workstation of a textile machine, comprising: guiding a moving yarn in a yarn-guiding unit of the traversing unit and moving the yarn-guiding unit linearly back and forth with a single traversing drive and a conversion element to traverse the yarn with respect to a pair of delivery rollers; operating the single traversing drive as a rotating motor; detecting a middle position (M) of the yarn-guiding unit with the aid of a sensor; and wherein during an interruption of the moving yarn, the yarn-guiding unit is positioned at the workstation such that the yarn-guiding unit is aligned with a draw-off tube of the workstation.

13. The method as in claim 11, further comprising detecting a position of the conversion element with the sensor in order to position the yarn-guiding unit on the workstation.

14. The method as in claim 11, further comprising driving the single traversing drive in accordance with a predefined speed profile.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages of the invention are described in the following exemplary embodiments. Wherein:

(2) FIG. 1 shows a schematic side view of a workstation comprising a traversing unit; and

(3) FIG. 2 shows a top view of section of the traversing unit.

DETAILED DESCRIPTION

(4) 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.

(5) FIG. 1 shows a schematic side view of a workstation 2 of a textile machine comprising a traversing unit 1. In the workstation 2, a yarn 3 is delivered by a delivery unit 4 and is wound onto a bobbin 10. In the exemplary embodiment shown here, the yarn 3 is formed by the delivery unit 4. In this exemplary embodiment, the delivery unit 4 is a rotor spinning unit, although it could also be an air-jet spinning unit, any other type of spinning unit, or a delivery bobbin of a winder.

(6) For the purpose of forming the yarn 3, the delivery unit 4 includes an opening unit 6 that forms individual fibers 7 from a sliver 5. The fibers 7 are guided into a rotor 8 which produces the yarn 3. The yarn 3 is drawn-off of an draw-off tube 19 of the delivery unit 4 with the aid of a pair of delivery rollers 9. Finally, the yarn 3 is wound onto the bobbin 10. The bobbin 10 is driven by a winding roller 11.

(7) In order to prevent the yarn 3 from cutting into the pair of delivery rollers 9, the yarn 3 can be traversed with the aid of the traversing unit 1. As a result, the yarn 3 is in contact in a wider area with the lateral faces of the delivery rollers of the pair of delivery rollers 9 while it is being drawn-off, thereby preventing the cutting-in.

(8) The traversing unit 1 includes a single traversing drive 13 that drives a yarn-guiding unit 12. In this exemplary embodiment, the yarn-guiding unit 12 is displaceable on a guide 16 in an axial direction X (see FIG. 2; not apparent here) of the pair of delivery rollers 9 with the aid of a holder 17. In this case, the yarn-guiding unit 12 is also connected to a cutting/blowing unit 20 and a measuring unit 21. The measuring unit 21 is installed downstream from the cutting/blowing unit 20 in the flow direction F of the yarn 3, according to FIG. 1. The yarn quality can be monitored with the aid of the measuring unit 21 and yarn defects can be detected with the aid of the measuring unit 21. Moreover, the traversing unit 1 includes a sensor 18.

(9) Due to the displacement of the yarn-guiding unit 12 along the axial direction X of the pair of delivery rollers 9, a linear reciprocating movement (a traversing movement C), is formed, with the aid of which the cutting-in by the yarn is prevented. The traversing movement C is oriented perpendicularly to the plane of the drawing in FIG. 1 and, therefore, is not labeled.

(10) The mode of operation of the traversing unit 1 is now described in conjunction with FIG. 2 which shows a top view of a section of the traversing unit 1. The traversing unit 1 includes not only the components already described with reference to FIG. 1, but also a conversion element 14, with the aid of which a rotational movement of the single traversing drive 13 is converted into the linear reciprocating movement or traversing movement C.

(11) The single traversing drive 13 is designed as a rotating motor. These types of rotating motors are also known as rotary-type motors and, in contrast to reversing motors, have only one direction of rotation, which is the direction of rotation in the present exemplary embodiment. As a result, the single traversing drive 13 can be more simply designed and controlled. A reversal of the direction of rotation of the single traversing drive 13 is therefore not necessary when the traversing movement C is to be reversed.

(12) With the aid of the sensor 18, a middle position M of the yarn-guiding unit 12 can be detected, whereby it can be detected, for example, whether the yarn-guiding unit 12 is aligned with the rotor 8 or with the draw-off tube 19. In this case, the middle position M of the yarn-guiding unit 12 is the position in which the yarn-guiding unit 12 is aligned with the draw-off tube 19. As a result, if a yarn break occurs, the yarn-guiding unit 12 can be moved to the middle position M and, therefore, in alignment with the draw-off tube 19. The piecing or splicing of the yarn is facilitated as a result, since the yarn end is located in a defined position with respect to the delivery unit 4, from which the yarn end can be returned into the delivery unit, namely the draw-off tube 19 in this case.

(13) The yarn-guiding unit 12 can advantageously include a cutting unit and/or a blowing unit, as has already been described with reference to FIG. 1. In this exemplary embodiment, these two units are combined to form a cutting/blowing unit 20. With the aid of the cutting unit of the cutting/blowing unit 20, the yarn 3 can be cut in two, for example, when the supply of the yarn 3 is halted, in order to obtain a defined yarn end. In addition, a yarn defect can be removed with the aid of the cutting unit. With the aid of the blowing unit of the cutting/blowing unit 20, the yarn end and/or the yarn 3 can be blown into the draw-off tube 19 or into the rotor 8. It is important for this reason as well that the cutting/blowing unit 20 of the yarn-guiding unit 12 is aligned with the draw-off tube 19. The blowing-in of the yarn 3 is simplified as a result.

(14) Moreover, the conversion element 14 is apparent in FIG. 2. In this exemplary embodiment, the conversion element 14 is designed as an eccentric element, in particular as an eccentric disk. The conversion element 14 is rotatable about a rotation point 15 and is driven by the single traversing drive 13, and so the conversion element 14 is set into the rotational movement .

(15) The conversion element 14 interacts with at least one guide element 22a, 22b which is designed as two parallel guide edges in this exemplary embodiment. The conversion element 14 is guided between the guide elements 22a, 22b. Alternatively, the guide elements 22a, 22b can also be designed as a slot, for example. Due to the interaction between the conversion element 14 and the guide elements 22a, 22b, the holder 17 on the guide 16 is set into the traversing movement C, and so the yarn 3 is traversed along the axial direction X of the pair of delivery rollers 9, which is merely schematically represented here. The traversing movement C is oriented in parallel to the axial direction X of the pair of delivery rollers 9 in this case.

(16) In the exemplary embodiment shown in FIG. 2, the yarn-guiding unit 12 is located in a middle position M. In the middle position M, the eccentric element faces the sensor 18 via its bulbous side, which is referred to here as the eccentric convexity 23. Alternatively, in the middle position M, the eccentric disk can also be situated so as to be rotated by 180, and so, in the middle position, the thinner side of the eccentric element, which is referred to here as the eccentric back 24, faces the sensor 18.

(17) In order to form the traversing movement C, for example, as shown in this exemplary embodiment, the conversion element 14, specifically the eccentric disk in this case, is rotated about the rotation point 15 with the aid of the single traversing drive 13 in the direction of rotation shown in FIG. 2. As a result, the eccentric convexity 23 is rotated in the direction of the guide element 22a. The eccentric back 24 is rotated in the direction of the guide element 22b, however. The eccentric convexity 23 presses the guide element 22a away in this case, and so the holder 17, including the yarn-guiding unit 12, moves to the left according to FIG. 2. When the eccentric disk has moved 90 further with respect to the orientation shown in FIG. 2 according to the direction of rotation , the maximum deflection of the holder 17 and of the yarn-guiding unit 12 toward the first side, specifically the left side in this case, has been reached. Upon further rotation of the eccentric disk, the holder 17 is moved back, specifically toward the right according to FIG. 2, until the eccentric convexity 23 has arrived at the guide element 22b. There, the holder 17 has the maximum deflection toward the right, according to FIG. 2. As a result, the traversing movement C can be formed in a single direction of rotation via a permanently rotating rotational movement of the single traversing drive 13. As a result, the single traversing drive 13 can be designed particularly simply and, therefore, a complicated control of the single traversing drive 13 is avoided.

(18) In order to enable a position of the conversion element 14 to be detected, a sensor 18 is situated adjacent to the conversion element 14. The sensor 18 can be designed as a Hall sensor, in order to enable the position of the conversion element 14 to be contactlessly measured. For this purpose, the conversion element 14 includes a magnetic element 25 in the area of the eccentric convexity 23, which is utilized as a measuring point for the Hall sensor. The magnetic element 25 could also be provided in the area of the eccentric back 24 or even at any other point, of course. It is merely essential, during the installation of the traversing device, that the conversion element 14 and the yarn-guiding unit 12 are positioned with respect to each other in such a way that the magnetic element 25 faces the sensor 18 in the middle position of the yarn-guiding unit 12. Depending on the design of the sensor 18 and of the conversion element 14, it would also be conceivable that the sensor 18 merely detects the eccentric convexity 23 or back 24 as such or detects a special recess or any other characteristic feature of the conversion element 14.

(19) The present invention is not limited to the exemplary embodiments which have been represented and described. Modifications within the scope of the claims are also possible, as is any combination of the features, even if they are represented and described in different exemplary embodiments.

LIST OF REFERENCE SIGNS

(20) 1 traversing unit 2 workstation 3 yarn 4 delivery unit 5 sliver 6 opening unit 7 fibers 8 rotor 9 pair of delivery rollers 10 bobbin 11 winding roller 12 yarn-guiding unit 13 single traversing drive 14 conversion element 15 rotation point 16 guide 17 holder 18 sensor 19 draw-off tube 20 cutting/blowing unit 21 measuring unit 22 guide element 23 eccentric convexity 24 eccentric back 25 magnetic element C traversing movement rotational movement X axial direction F flow direction of the yarn M middle position