EP1953275A1 - Drafting device with fibre condensing zone - Google Patents

Abstract

The stretching unit (1) has a driveable lower roller (6) attached to press rollers (7, 16). A mechanical unit compresses a fiber assembly moved between the press rollers in a compression zone (14). A transport unit (19) supports the fiber assembly between clamping lines (12, 15) of the press rollers in the compression zone. The mechanical unit compresses a guiding surface with which the fiber assembly is diverted in an axial direction of the lower roller around a part of the width of the fiber assembly from a transport direction.

Description

The invention relates to a drafting system for warping staple fibers with a drivable lower roller, the lower roller being associated with two pressure rollers, being provided in a compression zone between the two pressure rollers mechanical means for compressing a warped in the drafting fiber structure, and wherein in the compression zone transport means for supporting of the fiber structure to be compressed are provided between the nip lines of the two pressure rollers.

The invention further relates to a compressor component for a staple fiber distorting drafting system with a concave cylindrical jacket-shaped support surface for a lower roller of the drafting system, and with mechanical means for compressing a distorted in the drafting fiber structure, wherein the means for compressing at least two spaced-apart guide surfaces containing, directly to the Adjacent bearing surface.

A drafting and a compressor component of this type are by the WO 2006/005207 A1 State of the art. The known means for compressing are formed as a compression channel. The compression channel tapers in the transport direction of the fiber structure. The side surfaces of the compression channel form guide surfaces which lie on both sides of the fiber structure and whose distance is reduced in the transport direction of the fiber structure more and more. The fiber structure is thereby compacted and compacted. Different types of compression channels are described. What is common to all the compression channels is that the width of the compression channel in the end area determines the degree of compaction of the fiber structure. The distance of the lateral guide surfaces to each other must therefore be very small in order to compact the fiber structure sufficiently. It is usually only a few tenths of a millimeter. During operation, it often happens that this narrow end of the compression channel is clogged and operation is interrupted. Blockages can be through Thick areas of the fiber structure to be compacted and, above all, in the processing of natural fibers such as cotton, are caused by shell parts or nits.

The invention is based on the object to improve the means for compressing the distorted fiber structure and to reduce the tendency to clog.

The object is achieved in the drafting system in that the means for compacting contain at least one guide surface with which the fiber structure can be deflected in the axial direction of the lower roller by at least the amount of its width from its transport direction. In the compressor component, the object is achieved in that the two guide surfaces - seen in the circumferential direction of the cylinder jacket-shaped bearing surface - have a distance from one another.

The inventive design can be dispensed with a compression channel whose width must be matched to the width of the compressed fiber structure and which is very narrow due to its. The guide surfaces cause a deflection of the fiber structure transverse to its transport direction. An obliquely arranged to the transport direction of the fiber strand guide surface causes a compression and rolling of the fiber strand without an opposite guide surface would be required, which forms a narrow channel with the first guide surface. The inclined guide surface also acts alone as a deflection for the fiber structure. External and protruding fibers are applied and the fiber structure becomes very compact. When twisting the dreaded so-called "spinning triangle" then practically no longer occurs, so that the resulting yarn has a higher strength and a lower hairiness.

It is advantageous that the means for compaction contain at least two guide surfaces, which are arranged on gegenübliegenden sides of the fiber structure. The fiber structure is characterized by the guide surfaces successively deflected in different axial directions of the lower roller from its transport direction. The fiber structure is thereby deflected twice, whereby a very good compaction effect can be achieved. Depending on the requirements, of course, several guide surfaces can be provided, which redirect the fiber structure several times.

Even if two or more guide surfaces are provided, their distance from each other is greater than the width of the compressed fiber structure. The smallest distance is preferred between two guide surfaces even a multiple larger than the width of the compressed fiber structure, for example, at least twice as large. The compaction effect is no longer determined by the distance of the guide surfaces to each other, but by the deflection of the fiber structure from its transport direction. The distance between the guide surfaces to each other can therefore be chosen so large without affecting the compaction effect that even thick spots in the fiber structure or possibly containing nits or shell parts can no longer clog the compressor component.

A good compaction effect is achieved when the two guide surface are arranged on the compressor component so that along the cylinder jacket-shaped bearing surface of the compressor component exists an imaginary circumferential line which is cut by both guide surfaces.

The transport means for supporting the fiber structure to be compressed preferably supports the fiber structure uninterrupted in the entire compression zone. Preferably, the transport means is formed by the outer periphery of the lower roller on which the compressor component rests.

A good compaction effect can be achieved if the fiber structure in the compression zone is subject to a slight tensioning distortion. The Anspannverzug causes the fiber structure fits very well to the trained as deflection edges guide surfaces, as the individual, under tension staple fibers of the fiber structure have the desire to cover the shortest path between the two clamping lines. A slight tensioning distortion of the fiber structure in the compression zone can be achieved, for example, by different hardnesses of the elastic covers of the two pressure rollers and different degrees of contact pressure. Preferably, the reference of the pressure roller after the compression zone is softer than the reference of the pressure roller before the compression zone. In addition, the pressure roller can be pressed after the compression zone with a lower pressure force against the lower roller.

To extend the life of the pressure rollers, it is advantageous that the means for compressing are coupled to a traversing device of the drafting system, which alternates the fiber structure with a slow movement transversely to the transport direction.

If several fiber composites are warped in a drafting system, as occurs, for example, in the production of false twist, it is advantageous that for each fiber structure at least one guide surface is provided which compresses the fiber strand separately, without connecting to the other fiber composites. The compressor component advantageously contains at least two guide surfaces for each fiber structure. The guide surfaces are advantageously arranged so that the distances of the fiber composites are reduced in the compression zone, so that at the downstream of the compression zone nip the fiber composites are brought together to a small distance which is sufficient to keep the compacted fiber bundles separated.

Further advantages and features of the invention will become apparent from the following description of some embodiments.

• Figur 1 eine teilweise geschnittene Seitenansicht eines Streckwerks mit einem erfindungsgemäßen Verdichterbauteil,
• Figur 2 eine schematische Draufsicht in Richtung des Pfeiles II auf das Streckwerk der Figur 1, bei der die Druckwalzen weggelassen sind,
• Figur 3 eine stark vergrößerte Ansicht in Richtung des Pfeils III der Figur 1 auf das Verdichterbauteil,
• Figur 4 eine entlang der Schnittfläche IV-IV der Figur 3 geschnittene Ansicht des Verdichterbauteils,
• Figur 5 eine Ansicht ähnlich Figur 3 auf eine Variante eines Verdichterbauteils für Scheinzwirn.

Show it:

• FIG. 1 a partially sectioned side view of a drafting system with a compressor component according to the invention,
• FIG. 2 a schematic plan view in the direction of arrow II on the drafting of the FIG. 1 in which the pressure rollers are omitted,
• FIG. 3 a greatly enlarged view in the direction of arrow III of FIG. 1 on the compressor component,
• FIG. 4 one along the section IV-IV of FIG. 3 sectional view of the compressor component,
• FIG. 5 a view similar FIG. 3 to a variant of a compressor component for false twist.

This in FIG. 1 shown drafting system 1 consists essentially of drivable lower rollers 2, 4, 6 which pressable pressure rollers 3, 5, 7 are assigned and forgiven a fiber strand 8 of staple fibers in the transport direction A to the desired fineness. The fiber structure 8 is supplied to the drafting system 1 in the form of a fiber structure or a fuse by a Luntenführer 9 and can be performed during the delay in a conventional manner by Führungsriemchen 10 and 11. At the nip line 12 between the lower roller 6 and the pressure roller 7, the delay of the fiber structure 8 is completed. The finished warped fiber structure 13 passes through then a compression zone 14 in which it is compacted and compacted. The compression zone 14 is bounded on the outlet side by a clamping line 15, which is formed by a second, the lower roller 6 associated pressure roller 16. Following the nip line 15, the fiber structure 13 is given its rotation and there is the finished thread 17th

The drafting system 1 may be part of a spinning machine, in which the thread 17 is given its rotation, for example by an air nozzle or a ring spindle. In the case of a ring spinning machine, a plurality of drafting units 1 are arranged side by side and the lower rollers 2, 4, 6 are formed as continuous in the machine longitudinal direction of the lower cylinder. Such an embodiment is in FIG. 2 indicated. To improve the clarity are in FIG. 2 the pressure rollers 3, 5, 7 and 16 omitted. The pressure rollers of two adjacent drafting systems can be designed in a known manner with a common axis as Druckwalzenzwilling.

In the compression zone 14, a compressor component 18 is arranged, which further below described means 28 for compressing the warped fiber structure 13 contains. The fiber structure 13 is supported in the compression zone 14 by means of transport 19, since the finished warped, but still untwisted fiber structure 13 has almost no stability. The transport means 19 are formed by the outer periphery of the lower roller 6, which transports the fiber structure 13 from the nip line 12 to the nip 15. The fiber structure 13 lies between the nip lines 12 and 15 constantly on the transport means 19 and is not lifted from the lower roller 6.

The compressor component 18 includes a concave cylindrical jacket-shaped bearing surface 20 with which the compressor component 18 rests on the lower roller 6. The compressor component 18 is preferably held with the pressure rollers 7 and 16 in a pressure roller assembly 21 designed as a compact unit and guided so that it does not touch the pressure rollers 7 and 16. The pressure roller assembly 21 is held in a manner not shown by a load carrier of the drafting system 1. So that the compressor component 18 rests well with its bearing surface 20 on the lower roller 6, the compressor component 18 may be associated, for example, with a spring 22 or a magnet 23. Due to the sliding movement between bottom roller 6 and compressor component 8, it is advantageous to choose a wear-resistant material pairing. The lower roller 6 is usually made of hardened steel and may additionally have a coating. The compressor component 18 may preferably consist of ceramic. However, it may also be advantageous, the compressor component 18 at least on the support surface 18 of a abrasion-resistant composite material which is softer than the surface of the lower roller 6. If necessary, a worn compressor member 18 can be replaced more easily than a worn lower roller 6. As a composite material for the compressor member 18, a glass fiber reinforced plastic is well suited, since the compressor member can then be produced very simply and inexpensively as an injection molded part. Regardless of the selected material of the compressor component 18, it may be favorable to add to the material of the support surface 20 friction-reducing additives, for example in the form of inclusions of polytetrafluoroethylene.

To extend the life of the pressure rollers 3, 5, 7 of the drafting system 1, it may be advantageous to provide a traversing device 24. The traversing device 24 includes a Luntenführerschiene 25 coupled to a drive with which the Luntenführer 9 can be moved transversely to the transport direction A back and forth, as in FIG. 2 indicated by the double arrow B. So that now the compressor component 18 is always optimally positioned to the fiber structure 13 and thus the service life of the pressure roller 16 is increased, the compressor component 18 is preferably coupled to the traversing device 24. The coupling can be achieved, for example, by connecting the compressor component 18 to the sliver guide rail 25 via a fork 26 and a connecting arm 27. The fork 26 can consciously embrace the connecting arm 27 with some play or be sprung without play. Due to the fork 26, the pressure roller assembly 21 can be solved when swinging the load carrier of the drafting without hindrance from the connecting arm 27 and lift off from the lower roller 6. When replacing the pressure roller assembly 21, the fork 26 automatically engages again in the connecting arm 27 and positions the compressor component 18 according to the position of the Luntenführers. 9

The compressor component 18 with the means 28 for compressing the fiber structure 13 in the compression zone 14 will be described below with reference to the enlarged view of FIG. 3 described. In the illustrated case, the means 28 for compression by two guide surfaces 29 and 30 are formed. The guide surfaces 29 and 30 are arranged obliquely to the transport direction A and deflect the fiber structure 13 in the axial direction of the lower roller 6. The guide surfaces 29 and 30, even if they are arranged on opposite sides of the fiber structure 13, act differently than the guide surfaces on the known compressor components of the aforementioned prior art. The guide surfaces on the known compressor component compress the fiber structure 13 simultaneously from both sides, so that between the guide surfaces a narrow compression channel which determines the degree of compaction and at the same time is very susceptible to blockage. The guide surfaces 29 and 30 in the present compressor module 18 are arranged so that the fiber structure 13 from the guide surfaces 29, 30 successively in different axial directions of the lower roller 6 can be deflected from its transport direction A. The fiber structure 13 first reaches the guide surface 29 and is of this in the illustration after FIG. 3 deflected to the left from its transport direction A. After the fiber structure 13 has left the guide surface 29, it reaches the guide surface 30 and is deflected by this again to the right. This "zigzag deflection" of the fiber structure 13 is achieved in that the two guide surface 29 and 30 - seen in the circumferential direction of the lower roller 6 and the cylinder jacket-shaped support surface 20 - have a distance C to each other, that are arranged sequentially. There exists along the cylinder jacket-shaped contact surface 20 a in FIG. 3 Dashed line imaginary circumferential line 31 which is cut from the two guide surfaces 29 and 30 from opposite sides. The imaginary circumference 31 should run exactly perpendicular to the axis of the lower roller 6.

The smallest distance D of the two guide surfaces 29 and 30 has no influence on the width E of the compressed fiber structure 13. The distance D can therefore be chosen to be much greater than the width E of the fiber structure 13 at the nip 15, so that even in the fiber structure 13th present thick spots, nits or shell parts, the means 28 can easily pass for compacting and the compressor component 18 thereby not clogged. Blockages can be effectively prevented, in particular, if the distance D is greater than the width F of the warped fiber structure 13 at the nip line 12.

An essential measure of the compaction effect is the inclination angle of the guide surfaces 29 and 30 with respect to the transport direction A and the deflection of the fiber structure 13 in the axial direction of the lower roller 6. The deflection of the fiber structure 13 transversely to its transport direction A is at least the amount of its width F on the nip line 12. Thus, all over the width F distributed fibers of the fiber structure 13 can be merged. The compression can be supported by an appropriate choice of the angle α between the guide surface 30 and the support surface 20. In FIG. 4 It is clear that the guide surface 30 is directly adjacent to the support surface 20. As in FIG. 4 illustrated, the guide surface 30 may be arranged perpendicular to the support surface 20 and to the surface of the lower roller 6. The fiber structure 13, which rests on the transport means 19 is pressed into the corner between the guide surface 30 and transport means 19 and compacted there. There is no further surface on the compressor component 18, on which the fiber structure 13 rests. to Changing the compression effect, the angle α and values smaller or greater than 90 °.

In an embodiment of the invention can - as in FIG. 4 indicated - a web 38 may be provided on the compressor component 18, which extends above the transport means 19 of the guide surface 30 on one side of the fiber structure 13 to the other side of the fiber structure 13. The web 38 practically establishes a connection between the guide surfaces 29 and 30, so that the compressor component 18 is in one piece. In contrast to the cited prior art, the web 38 is no longer involved in the compression of the fiber structure 13. The compressor component 18 can therefore no longer be lifted off the lower roller 6 by a thick point in the fiber structure 13 and pressed against the upper roller 16. The height H of the guide surface 30, and of course in a manner not shown also the guide surface 29, is therefore preferably greater than the width E of the compressed fiber structure thirteenth

It should be noted that, for manufacturing reasons, the guide surface 29 can also be continued by the dashed contour 32 of the compressor component 18. Although between the contour 32 and the guide surface 30 is formed with the web 38 a kind of channel, but this channel is not involved in the compression effect of the compressor component 18. First, the guide surface 29 ends in any case at the deflection edge 33, whereby the fiber structure 13 does not come into contact with the contour 32 at all. Second, the distance D and the height H are much too large to cause compaction of the fiber structure 13.

Depending on the hardness of the elastic covers of the pressure rollers 7 and 16 and the pressure forces of the pressure roller 7 and 16 to the lower roller 6, the tensile stress acting on the fiber structure 13 in the compression zone 14 can be influenced. By a softer relation on the pressure roller 16 than on the pressure roller 7, a slight tensioning distortion in the fiber structure 13 can be produced, which can improve the compression. By a slight tension in the fiber structure 13, this has the endeavor in the compression zone 14 to take the shortest possible route. The fiber structure 13 applies under slight tension to the deflection edge 33 of the guide surface 29 and the deflection edge 34 of the guide surface 30 and is optimally compressed. Preferably, the distance between the two clamping lines 12 and 15 is as small as possible, in particular smaller than the mean fiber length of the staple fibers in the fiber structure 13. To reduce the distance of the nip 15 of the nip 12, the diameter of the pressure roller 16 can be reduced. Thus, the service life of the pressure roller 16 is not too small with a smaller diameter and thus also prevents the Fiber wrap 13 wrapped around the pressure roller 16, the pressure roller 16 as in FIG. 1 indicated to be associated with a protective apron 35. The protective apron 35 wraps around the pressure roller 16 and is guided above the pressure roller via a guiding and / or tensioning device 36, which can likewise be attached to the pressure roller assembly 21.

In an unillustrated embodiment of the invention, it may be advantageous to use more than the illustrated two guide surfaces 29 and 30. By additional guide surfaces, the zigzag deflection of the fiber structure 13 can be extended and thereby the compression can be improved. Depending on the fiber material and in particular with low tensioning distortion in the compression zone 14, it may also be sufficient to use only one guide surface 30 with the deflection edge 34 for compacting the fiber structure 13. In particular, with only one guide surface 30, a curl occurring in the deflection of the fiber structure from its transport direction A can be utilized to densify the fiber structure 13. The slight rolling movement about the longitudinal axis of the fiber structure 13 occurs because the transport means 19 continues to move exactly in the transport direction A, even if the fiber structure 13 is displaced transversely to the transport direction A by the inclined guide surface 30.

In FIG. 5 a variant of a compressor component 18 is shown, which can be used for the production of false twist 37. In the production of false twist 37 two fiber assemblies 13 are warped separately from each other in a drafting 1 and performed separately through the compression zone 14. After the nip line 15, the two fiber composites 13 are fed to a common twist element and spun into a dummy thread 37. The means 28 for compressing the apparent component compressor component 18 are basically constructed in the same way as described above for a single fiber assembly 13. Like reference numerals designate like parts. A renewed description of all details can therefore be dispensed with at this point. Preferably, the compactor component 18 for false twist 37 has at least two guide surfaces 29, 30 for each fiber strand 13. The guide surfaces 29, 30 for the two fiber composites 13 are advantageously arranged mirror-symmetrically in a manner such that the distance of the two fiber composites 13 from the nip line 12 to the nip 15 is reduced. The two fiber composites 13 should have at the nip 15 only a very small distance from each other, which is sufficient to keep the two compacted fiber composites 13 separated.

Claims (13)

Drafting device (1) for warping staple fibers with a drivable lower roller (6), the lower roller (6) being associated with two pressure rollers (7, 16), mechanical means being provided in a compression zone (14) between the two pressure rollers (7, 16) (28), for compressing a distorted in the drafting (1) fiber structure (13) are provided, and wherein in the compression zone (14) transport means (19) for supporting the fiber structure to be compacted (13) between the nip lines (12, 15) both, pressure rollers (7, 16) are provided, characterized in that the means (28) for compressing at least one guide surface (29, 30), with which the fiber structure (13) in the axial direction of the lower roller (6) around at least the Amount of its width (F) from its transport direction (A) is deflected. Drawframe according to Claim 1, characterized in that the means (28) for compacting contain at least two guide surfaces (29, 30) whose smallest distance (D) from one another is greater than the width (E) of the compacted fiber structure (13). Drawframes according to claim 1 or 2, characterized in that a respective guide surface (29, 30) on opposite sides of the fiber structure (13) is arranged, and that the fiber structure (13) of the guide surfaces (29, 30) successively in different axial directions the lower roller (6) from its transport direction (A) is deflected. Drawframe according to one of claims 1 to 3, characterized in that the means (28) for compression with a traversing device (24) of the drafting system (1) are coupled. Drawframe according to one of claims 1 to 4, characterized in that at least one pressure roller (7; 16) is looped around by a protective strap (35). Compressor component (18) for a drafting machine (1) with a concave cylindrical jacket-shaped bearing surface (20) for a lower roller (6) of the drafting system (1), and with mechanical means (28) for compressing a fiber structure distorted in the drafting system (1) ( 13), wherein the means (28) for compressing at least two spaced guide surfaces (29, 30) adjacent to the support surface (20) directly adjacent, characterized in that the two guide surfaces (29, 30) - Viewed circumferential direction of the cylinder jacket-shaped bearing surface (20) - a distance (C) to each other. Compressor component according to claim 6, characterized in that on the cylinder jacket-shaped bearing surface (20) an imaginary circumferential line (31) exists, which is cut by the two guide surfaces (29, 30). Compressor component according to claim 7, characterized in that the peripheral line (31) of the two guide surface (29, 30) is cut from opposite sides. Compressor component according to one of claims 6 to 8, characterized in that the smallest distance (D) of the two guide surfaces (29, 30) is greater than the width (E) of the compressed with the compressor component (18) compressed fiber structure (13). Compressor component according to one of claims 6 to 9, characterized in that the height (H) of the two guide surfaces (29, 30) is greater than the width (E) of the compressed with the compressor component (18) compressed fiber structure (13). Compressor component for the production of a false twist of several fiber composites according to one of claims 6 to 10, characterized in that at least two guide surfaces (29, 30) are provided for each fiber strand (13). Compressor component according to one of claims 6 to 11, characterized in that at least the cylinder jacket-shaped bearing surface (20) consists of a composite material. Compressor component according to claim 12, characterized in that the composite material contains plastic and / or glass fibers.

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