WO2003097911A1

WO2003097911A1 - Thread draw-off nozzle

Info

Publication number: WO2003097911A1
Application number: PCT/DE2003/001415
Authority: WO
Inventors: Ilias Efthimiou
Original assignee: Ilias Efthimiou
Priority date: 2002-05-17
Filing date: 2003-05-02
Publication date: 2003-11-27
Also published as: DE10393063B4; DE10222635A1; DE10393063D2; AU2003232619A1

Abstract

The invention relates to a thread draw-off nozzle (24) for an open-end spinning machine. According to the invention, structures of successive rib-like elevations or recesses are arranged on the thread feeding surface (37). These elevations or recesses extend approximately in the circumferential direction and their lengths are equal to or shorter than the circumference of a circle of the same radius from the central axis (46). This results in an interruption of the thread supporting surface (47) that, in turn, improves the spinning stability and thread properties.

Description

Fadenabzuσsdüse

The invention relates to a thread draw-off nozzle for an open-end rotary spinning machine.

In the case of open-end rotor spinning devices, it is generally important that the real yarn rotation initiated by rotation of the spinning rotor runs evenly into the end of the yarn that is being created. In many cases, the real yarn twist is mainly introduced into the piece of yarn that is located between the thread take-off nozzle and a thread take-off device of the open-end rotor spinning device. In contrast, the real yarn twist often runs into the yarn piece in front of the thread take-off nozzle only incompletely. If this means that the yarn rotation is caused, this can have a negative impact on the spinning stability of the open-end rotor spinning device.

In addition to a design of the thread take-off nozzle which is optimized with regard to the spinning stability, further boundary conditions must be observed. Thread take-off nozzles should remain in use for as long as possible without significantly changing the spinning stability. The spun thread is drawn through the thread take-off device over the thread take-off nozzle, the thread rotating as a result of the rotor rotation. The resulting friction between the thread and the thread take-off nozzle leads to wear on the latter. The aim should be to obtain the highest possible wear resistance. This is influenced both by the choice of material and by the shape of the thread take-off nozzle.

In many cases it is also desirable to be able to use the thread take-off nozzle for spinning different materials. Here too, the shape of the thread take-off nozzle has an influence on the variety of possible uses of the thread take-off nozzle.

Thread take-off nozzles generally have a flat plate-like section, the center of which narrows like a funnel to form a thread take-off channel. To improve the spinning stability, the surface structure of the plate-like section and the funnel-shaped area have already been influenced. DE-OS 25 44 721, DE 33 44 741 AI and EP 0422615 B1 each describe thread draw-off nozzles which have notch-like depressions in the region of the funnel-shaped region. According to DE-OS 25 44 721, the thread take-off nozzle is made of a ceramic material and has a roughness depth of 0.2 μm to 0.7 μm in the area of the thread inlet funnel. In addition, notches are arranged here, which can have different notch opening angles.

From DE 33 44 741 AI thread take-off nozzles with a replaceable, made of sheet steel and hardened thread inlet funnel are known. The thread feed hopper is provided with notches or protruding beads. In addition, the notches can be arranged in two ring-like arrangements which lie one behind the other in the thread running direction.

From EP 0422615 Bl a thread take-off nozzle is known which has notches in the area of the thread entry zone and protrusions in the area of the thread take-off channel. While the notches are intended to improve the spinning stability of the open-end spinning device, the projections in the thread take-off channel serve to produce a particularly hairy yarn.

It has become known about these spinnerets that they impose restrictions on the achievable yarn quality.

In addition, attempts have been made to provide thread withdrawal nozzles with a spiral structure. For example, from DE 42 24 632 AI a thread take-off nozzle with spirally extending, with respect to the thread running, straight surfaces is known. The surfaces are at an angle to achieve thread deflection points arranged inclined. In such an embodiment, the thread is supported on the surfaces that are straight with respect to the thread running direction over a relatively large area. As a result, the surface pressure acting on the thread is reduced to a permissible level. In addition, the thread deflection points, which are formed between the surfaces arranged at an angle to one another, transmit thrust components to the thread. These have the effect that the yarn twist in the area between the rotor groove and the thread take-off nozzle is kept at an increased value. In the case of these thread take-off nozzles known as "spiral nozzles", the thread slides as a rule over elevations of the spiral structure. The orientation thereof is such that a thrust component in the direction of the rotor groove becomes effective when the thread rotates correspondingly on the piece of yarn being produced This thrust component has the effect that the real yarn twist introduced between the rotor groove and the thread take-off nozzle is at least partially prevented from leaving this area The effect may decrease if a thread running through the nozzle rounds off the edges between the straight surface pieces with increasing wear.

From DE 197 38 382 AI it is also known to provide thread take-off nozzles with a spiral rib which runs into the funnel-shaped inlet area of the thread take-off channel, this rib being interrupted by axially extending notches in the funnel area. This nozzle is said to achieve good spinning stability, small variations in yarn tenacity and yarn twist.

All of the nozzles mentioned are subject to certain restrictions with regard to the processable yarns and wear resistance. It is therefore an object of the invention to provide a draw-off nozzle which allows long-term stable work and the processing of different fibers.

This object is achieved with the thread draw-off nozzle according to claim 1:

The thread take-off nozzle according to the invention has, at least in the area of the thread inlet surface and the funnel-shaped input area that leads to the thread take-off channel, a profile which is formed from elongated profile elements. These extend transversely to the radial direction of the thread inlet surface and have at most a length which corresponds to the circumference of a circle defined by them about the central axis of the thread draw-off nozzle. The profile elements are thus, for example, rings concentric with one another with or without interruptions or a spiral structure which consists of individual sections, the length of which corresponds at most to the respective circular length.

The division of a rib or groove structure into individual concentric rings or arc sections means that the area over which the thread runs is not contiguous. This has proven to be advantageous with regard to the swirl propagation in the area in front of the thread take-off nozzle. This already applies to the ring structure. This applies in particular to the interrupted structures in which the thread repeatedly encounters the beginning of the ribs or the beginning of the groove during its rotational movement, which can support a twist generation. It has also been shown that such structures work reliably regardless of the thread material and are less prone to wear. Tests have shown that with a groove structure, in particular the yarn uniformity including the thin spots, thick spots and nits could be reduced. Such groove structures also lead to reduced yarn hairiness, especially with the long, protruding hair. This compact yarn structure has enormous advantages, especially for further processing in the weaving mill, ie there is a reduced frequency of downtimes due to a lower tendency to staple.

The combination of groove and rib structure allows the yarn hairiness to be influenced in a targeted manner. This can lead to advantages in terms of handle when using such yarns in knitting. With increasing wear, for example, the rib structures become lower, but this hardly affects their effectiveness.

Further details of advantageous embodiments of the invention result from the drawing, from the description or from subclaims.

Exemplary embodiments of the invention are illustrated in the drawing. Show it:

FIG. 1 shows an open-end spinning device in a schematic sectional illustration, FIG. 2 the spinning rotor and the thread take-off nozzle of the open-end spinning device according to FIG. 1,

Figure 3-8 different embodiments of the thread take-off nozzle according to the invention in a longitudinal section and

Figure 9-14 further embodiments of the thread take-off nozzle according to the invention in plan view.

FIG. 1 illustrates an open-end spinning device 1, which as essential elements has a feeding device 2, a spinning device 3 fed by it and a thread take-off device 4 which interacts with it.

The feed device 2 includes a dissolving device 5 with a dissolving roller 6, to which a feed roller 7 is assigned. This leads the opening roller 6 to a sliver 8. The opening roller 6 runs in a housing 9 which has a dirt separation opening 11 on its underside. A fiber feed channel 12 extends from the housing 9 to the spinning device and feeds fibers 14 to it in an air-borne manner.

The spinning device 3 includes a spinning rotor 16 which is rotatably arranged in a closed housing 15 and which is carried by a shaft 17 and is driven to rotate in a predetermined direction of rotation. The spinning rotor 16 has a rotationally symmetrical interior which tapers conically towards its opening. In the transition between its frustoconical wall and its substantially flat bottom, a rotor groove 18 is formed, in which a fiber band 19 lies during operation.

The fiber feed channel 12 opens at a channel plate adapter 21 at an opening 22 which projects into the interior of the spinning rotor 16. The housing 15 is provided with a suction opening 23 to which a vacuum line is connected. An air flow passing through the housing 15 is generated via the suction opening and supports the introduction of the fibers into the spinning rotor 16. The channel plate adapter 21 holds a thread take-off nozzle 24 centrally in the spinning rotor 16, via which a thread 25 which is being formed is drawn off from the spinning rotor 16. For this purpose, a thread take-off tube 27 connects to the thread take-off nozzle or its thread take-off channel 26, via which the thread 28 is guided to a thread take-off roller pair 29 and from there to a bobbin roller 31 and a bobbin 32.

The spinning device 3 is illustrated separately in FIG. 2. As can be seen, the thread draw-off nozzle 24 has a ceramic body 34 which is held in a metal frame 35.

The ceramic body 34 determines the function of the thread draw-off nozzle. It is designed in a special way and illustrated separately in FIG. 3. On its side facing the bottom of the spinning rotor 16, it forms a nozzle head 36 with a plate-like thread inlet surface 37 which is round in outline. This contains a funnel-like section in the center, which forms an entrance area 38 for the thread take-off channel 26. The input area 38 preferably has a substantially symmetrical, for example a circular or a polygonally delimited, cross section. The thread inlet surface 37, including the input area 38, is provided with a profile 39 which is formed, for example, by a plurality of ribs 41 to 45 designed as concentric rings. Each rib 41 to 45 in each case forms a ring which follows a circle which is concentric with the central axis 46 of the fiber withdrawal channel 26. Thus the length of each continuous rib 41 to 45 corresponds to the circumference of this circle. Each rib 41 to 45 has on its side facing away from the nozzle head 36 a thread Support surface 47, which is indicated in Figure 3 only for the ribs 43 and 44. The thread support surfaces 47 of all the ribs 41 to 45 form a common, but not contiguous thread support surface over which the thread slides when the thread is drawn off. As a result of their concentric alignment with the central axis 46, the thread does not receive any feed component when it is rotated over the thread support surfaces 47.

Figure 4 illustrates a modified embodiment of the nozzle head 36. The metal frame 35 is identical - only the ceramic body 34 is modified. A whole series of different nozzle heads 36 can thus only be obtained by accommodating different ceramic bodies 34 in the metal frame 35.

The ceramic body 34 according to FIG. 4 has a plurality of annular ribs 43, 44, 45 arranged concentrically to one another on its thread inlet surface 37, which coincide with the ribs 43, 44, 45 according to FIG. 3. In contrast, the ribs 41, 42 arranged in the entrance area 38 are designed in the manner of a spiral. These impart a feed movement to the thread rotating in relation to the nozzle head 36 if the direction of rotation is selected accordingly. The direction of rotation can also be selected in the opposite direction, so that a force component counteracts the thread take-off.

A further embodiment of the thread draw-off nozzle 24 according to the invention is illustrated in FIG. 5. The profiling 39 here in turn comprises several, for example three, concentric ribs 43, 44, 45, which are essentially in FIG the plate-like flat section of the thread inlet surface

37 are arranged. In contrast, to form the profiling, several depressions or grooves 51, 52, 53 are accommodated in the entrance area 38, which extend approximately parallel to the central axis 46. The grooves too

51, 52, 53 can contribute to the thread twisting caused by the rotation of the spinning rotor 16 already in the area of the thread between the fiber band 19 made of loose individual fibers 19a (FIG. 2) and the entrance area

38 initiate. FIG. 2 illustrates an embodiment of the thread take-off nozzle 24 in which the grooves 51,

52, 53 or corresponding notches cut at least one of the ribs 43, 44, 45.

A thread draw-off nozzle 24 further developed in this direction is illustrated in FIG. 6. The notches 51, 52 penetrate the two inner ribs 41, 42 which, like the other ribs 43, 44, 45, are each designed as rings concentric with the central axis 46. The length of each rib thus corresponds precisely to the corresponding circumference of the circle of the same radius concentric with the central axis 46.

FIG. 7 illustrates a further modified embodiment of the thread draw-off nozzle 24, in which the two inner ribs 41, 42, as in the exemplary embodiment according to FIG. 4, are combined to form a continuous spiral rib. This is in turn penetrated by the grooves 51, 52. The remaining ribs 43, 44, 45 are circular and thus just as long as the corresponding circumference. The grooves 51, 52 (as well as further grooves distributed uniformly around the circumference, not shown, which extend parallel to the central axis 46) divide the spiral rib 41, 42 into short individual sections which are shorter than the circumference of the respective circle of the same diameter , The grooves influence the penetration of the thread twist caused by spinning through the thread take-off nozzle 24. In particular, this thread design proves to be relatively robust against the effects of wear.

Another embodiment of the thread take-off nozzle 24 is illustrated in FIG. 8. The embodiment is made here in such a way that there are no ribs in the entrance area 38 but only the grooves 51, 52, 53 and further, not illustrated, also parallel to the central axis 46 and equally spaced around the circumference. Otherwise, the thread support surface 37 carries the ribs 43, 44, 45 which have already been explained several times in connection with FIGS. 3 to 7.

A further embodiment of the thread draw-off nozzle 24 is illustrated in FIG. In this case, the ribs 43, 44, 45 are each interrupted. The beginnings and the ends of the respective rib sections each lie on lines L1, L2, which are approximately radially oriented to the central axis 46. However, other aspect ratios are also possible. For example, the lines L1, L2 can be curved or arranged parallel to one another. In the exemplary embodiment according to FIG. 9, the entrance area 38 is free of recesses or elevations. However, it can also have recesses or Surveys can be provided according to one of the above-described embodiments. In addition, the entrance area 38 can be polygonally delimited. Corresponding depressions can also be provided instead of the ribs 43, 44, 45. In addition, it is possible to replace adjacent sections of the ribs 43, 44, 45 with depressions. For example, it is possible to leave the rib sections 43a, 43b illustrated in FIG. 9 as rib sections and to replace the remaining sections 43c, 43d with depressions. A similar procedure can be followed for the other ribs 44, 45, ribs and depressions also being able to alternate in the radial direction.

A modified embodiment can be seen in FIG. 10. This differs from the embodiment described above in that the rib sections of the ribs 43, 44, 45 are offset from one another such that the ribs are each in a gap. This has the advantage that the circumferential thread runs smoothly.

In the embodiment of the thread take-off nozzle 24 according to FIG. 11, arc-shaped, rib-like elevations 43b, 43a are alternately arranged with corresponding groove-shaped depressions 43c, 43d. The arcuate sections 43a, 43b, 43c and 43d are arranged on a circle concentric to the central axis 46. The respective length is significantly shorter than the circumference.

FIG. 12 illustrates a further embodiment of the thread draw-off nozzle 24. This is based on the embodiment according to FIG. 10, with some of the arcuate rib sections being provided with notches. This is strikes the rib sections 44a, 44b, 44c, 44d of the middle rib 44 in the exemplary embodiment presented. Corresponding notches 61, 62, 63, 64 can, for example, be as deep as the rib section in question is high. The notches are preferably arranged in areas in which they are aligned in the radial direction with gaps in the other ribs 43, 45.

Another possibility of the inventive design of the thread inlet surface 37 can be seen in FIG. 13. Here rib sections 65 are distributed over the entire thread inlet surface 37 in such a way that they form a spiral when strung together. Each rib section 65 is approximately arc-shaped and shorter than the circumference of a circle of the same radius around the central axis 46. The individual arc-shaped rib sections 65 are preferably in a gap, so that the thread runs smoothly. Grooves or raised structures can be introduced in all or some rib sections 65. The rib sections 65 can also be replaced by corresponding recesses.

FIG. 14 illustrates a combined embodiment of the thread take-off nozzle 24, in which the ribs 43 and 45 are divided into four and three sections, respectively. The rib 44, however, is continuous. This embodiment can also be combined with all other embodiments, in particular with regard to the design of the entrance area 38. For example only, the entrance area 38 is illustrated here with a hexagonal cross section. In a thread take-off nozzle 24 for an open-end spinning machine, structures are arranged on the thread inlet surface 37 in succession of rib-like elevations or depressions which extend approximately in the circumferential direction and whose length is equal to or less than the circumference of a circle of the same radius around the central axis 46 an interruption of the thread support surface 47 is achieved in a manner that improves the spinning stability and the thread properties.

Claims

Claims:

1. thread take-off nozzle (24) for an open-end rotor spinning machine,

with a nozzle head (36), on which a thread inlet surface (37) is formed, which is arranged concentrically around a thread take-off channel (26), the thread inlet surface (37) having a funnel-shaped entrance area (38) which connects to the thread take-off channel (26) connects,

the thread inlet surface (37) being provided with a profile (39) which has elongated profile elements (41, 42, 43, 44, 45) which are oriented essentially in the circumferential direction with respect to a longitudinal axis (46) of the thread take-off channel (26), wherein the length of the profile elements (41, 42, 43, 44, 45) reaches at most the length of the circumference of a circle determined by them about the central axis (46) and wherein profile elements (41, 42, 43, 44, 45) both in the funnel-shaped entrance area (38) and outside of the same.

2. Thread take-off nozzle according to claim 1, characterized in that at least some of the profile elements (41, 42, 43, 44, 45) are arranged on circles which are arranged concentrically to the central axis (46).

3. Thread take-off nozzle according to claim 2, characterized in that these profile elements (41, 42, 43, 44, 45) form closed circles.

4. Thread take-off nozzle according to claim 2, characterized in that these profile elements (41, 42, 43, 44, 45) are shorter than the respective circle.

5. Thread take-off nozzle according to claim 1, characterized in that at least some of the profile elements (41, 42, 43, 44, 45) are raised ribs.

6. Thread take-off nozzle according to claim 1, characterized in that at least some of the profile elements (41, 42, 43, 44, 45) are depressions.

7. Thread take-off nozzle according to claim 1, characterized in that at least some of the profile elements (41, 42, 43, 44, 45) are arranged to overlap in the radial direction.

8. Thread take-off nozzle according to claim 7, characterized in that the overlapping profile elements (41, 42, 43, 44, 45) each have ends aligned in common lines (L1, L2).

9. Thread take-off nozzle according to claim 7, characterized in that at least some of the profile elements (41, 42, 43, 44, 45) are arranged in the radial direction on gap.

10. Thread take-off nozzle according to claim 1, characterized in that profile elements (41, 42, 43, 44, 45) arranged in a row oriented in the circumferential direction are alternately formed as an elevation and as a depression.

11. Thread take-off nozzle according to claim 1, characterized in that the profile elements (41, 42, 43, 44, 45) have a decreasing distance from one another with a decreasing distance from the thread take-off channel (26).

12. Thread take-off nozzle according to claim 1, characterized in that the profile elements (44, 45) in the input area (38) have an angle of inclination to a circle concentric about the central axis, which is greater than a corresponding angle of inclination of a profile element (43 , 44, 45).

13. Thread take-off nozzle according to claim 1, characterized in that profile elements (41, 42, 43, 44, 45) are provided which cross each other.

14. Thread take-off nozzle according to claim 1, characterized in that raised elongated, rib-like profile elements (41, 42, 43, 44, 45) are provided with a notch (61, 62, 63, 64).

15. Thread take-off nozzle according to claim 1, characterized in that raised profile elements (41, 42, 43, 44, 45) have an upper side (47), the surface quality of which deviates from the other surface quality of the thread inlet surface (37).

16. Thread take-off nozzle according to claim 15, characterized in that profile elements (41, 42, 43, 44, 45) are roughened on their upper side.

7. Thread take-off nozzle according to claim 1, characterized in that the thread inlet surface (37) is formed on a ceramic element (34).