Yarn deflection unit

1. A yarn deflection unit for a textile machine, having a housing comprising a curved wall section for forming a radially outer wall section of a curved yarn deflection channel,

characterised in that

the curved wall section has a yarn guiding groove extending along the curvature for receiving and guiding a yarn and that the yarn guiding groove is delimited in the curvature direction by ends forming respective yarn passages, the groove depths of which ends, proceeding from the common groove base, are different from each other.

2. The yarn deflection unit according to claim 1 , characterised in that the yarn guiding groove forms a V- or U-shaped cross-sectional shape along the curvature.

3. The yarn deflection unit according to claim 1 characterised in that the curved wall section having the yarn guiding groove has a circular-arc-like cross-section along the curvature.

4. The yarn deflection unit according to claim 1 , characterised in that the housing has a contact section for the contacting of an end section of a yarn guiding element, which end section is open toward the yarn guiding groove and via which end section a yarn can be guided into the yarn guiding groove or out of the yarn guiding groove.

5. The yarn deflection unit according to claim 1 , characterised in that the yarn deflection unit has a flow guiding element, which guides an air flow directed into the yarn deflection channel toward the yarn guiding groove.

6. The yarn deflection unit according to claim 5 , characterised in that the flow guiding element and a retainer are coupled to each other or are formed from one piece.

7. The yarn deflection unit according to claim 6 , characterised in that the flow guiding element and/or the retainer can be detachably fastened to the housing, wherein in the fastened state the flow guiding element or the retainer forms a wall section of the yarn deflection channel which lies opposite the open yarn guiding groove.

8. A yarn deflection unit for a textile machine, having a housing comprising a curved wall section for forming a radially outer wall section of a curved yarn deflection channel,

characterised in that

the curved wall section has a yarn guiding groove extending along the curvature for receiving and guiding a yarn and the housing has a contact section for the contacting of an end section of a yarn guiding element, which end section is open toward the yarn guiding groove and via which end section a yarn can be guided into the yarn guiding groove or out of the yarn guiding groove and the yarn deflection unit has a retainer for retaining the open end section in at least one direction different from the guiding direction of the yarn.

9. A yarn deflection unit for a textile machine, having a housing comprising a curved wall section for forming a radially outer wall section of a curved yarn deflection channel,

characterised in that

the curved wall section has a yarn guiding groove extending along the curvature for receiving and guiding a yarn The yarn deflection unit according to claim 1 , characterised in that and the housing has a housing side wall, which is connected to the curved wall section and extends transversely thereto and forms a holder for a yarn deflection roller, which, when held, forms a wall section of the yarn deflection channel which lies opposite yarn guiding groove.

10. The yarn deflection unit according to claim 9 , characterised in that the housing has, on the side opposite the housing side wall, an air flow passage that communicates with the yarn deflection channel.

11. The yarn deflection unit according to claim 10 , characterised in that the air flow passage is formed by a protrusion, which is connected to the curved wall section and extends transversely thereto, an intermediate space for the intermediate positioning of the yarn deflection roller thus being formed, wherein such a width of the intermediate space is chosen that the yarn deflection roller can be positioned on the holder such that an air gap is formed between the yarn deflection roller and the protrusion, the protrusion being shorter, proceeding from the curved wall section in an extension direction parallel to the opposite housing side wall, than the opposite housing side wall.

12. The yarn deflection unit according to claim 11 , characterised in that the protrusion is formed by a circular arc segment.

13. The yarn deflection unit according to claim 12 , wherein width of the circular arc segment has a width along the extension direction between 0.3 mm and 5 mm.

14. A method for operating a workstation of a textile machine, having a winding device for winding a take-up package, a yarn feeding device for feeding a yarn and a yarn draw- off device, which is interposed between the winding device and the yarn feeding device in the yarn path, for drawing off a yarn from the take-up package;

characterised in that

a yarn deflection unit for a textile machine, having a housing comprising a curved wall section for forming a radially outer wall section of a curved yarn deflection channel, the curved wall section having a yarn guiding groove extending along the curvature for receiving and guiding a yarn, and wherein the yarn defection unit is arranged interposed between the winding device and the yarn draw-off device in the yarn path,

take-up-package-side yarn end is transported from a take-up package, which is rotatably retained in the winding device, via the yarn deflection unit to the yarn draw-off device with air flow accompaniment after a yarn interruption, and

the yarn end is inserted into the yarn draw-off device,

wherein an air flow used to accompany the yarn is reduced or switched off when or after the yarn is inserted into the yarn draw-off device.

15. A workstation of a textile machine, having a winding device for winding a take- up package, a yarn feeding device for feeding a yarn and a yarn draw-off device, which is interposed between the winding device and the yarn feeding device in the yarn path, for drawing off a yarn;

characterised in that

a yarn deflection unit for a textile machine, having a housing comprising a curved wall section for forming a radially outer wall section of a curved yarn deflection channel, the curved wall section having a yarn guiding groove extending along the curvature for receiving and guiding a yarn, and wherein the yarn defection unit is arranged interposed between the winding device and the yarn draw-off device in the yarn path, is arranged, a deflection angle (α) provided by the yarn deflection unit being less than 85°.

16. The workstation according to claim 15 , wherein the deflection angle (α) provided by the yarn deflection unit being 70° or less.