Title of Invention

SPINNING MACHINE HAVING A PLURALITY OF ADJACENTLY ARRANGED SPINNING STATIONS.

Abstract

TITLE: SPINNING MACHINE HAVING A PLURALITY OF ADJACENTLY ARRANGED SPINNING STATIONS. The invention relates to a spinning machine having a plurality of spinning stations arranged adjacent to one another, which each comprise a drafting unit having a front roller pair which forms a front nipping line as well as a condensing zone arranged downstream hereof which condenses a drafted fibre strand, which condensign zone comprises an air-permeable transport belt which transports the fibre strand, and which transport belt is guided on a sliding surface comprising a suction slit, whereby the sliding surfaes for a plurality of transport belts are arranged on a suction tube extending over a plurality of spinning stations, and which project into the wedge-shaped gap formed by the respective front roller pair. The suction tube is arranged at a distance from the front roller pairs, and in that the sliding surfaces with the suction slits are arranged in single housings attachable to the suction tube, which single housings bridge the gap between the suction tube and the wedge-shaped gaps.

Full Text

Spinning machine having a plurality of adjacently arranged spinning stations The present invention relates to a spinning machine having a plurality of spinning stations arranged adjacent to one another, which each comprise a drafting unit having a front roller pair which forms a front nipping line as well as a condensing zone arranged downstream there of which condenses a drafted fibre strand, which condensing zone comprises an air- permeable transport belt which transports the fibre strand, and which transport belt is guided on a sliding surface comprising a suction slit, whereby the sliding surfaces for a plurality of transport belts are arranged on a suction tube extending over a plurality of spinning stations, and which project into the wedge-shaped gap formed by the respective front roller pair. The drafted fibre strand in a drafting unit of a spinning machine subsequently receives its spinning twist. If this spinning twist was applied directly after the drafting process, then a so- called spinning triangle would occur at the front roller pair of the drafting unit, which spinning triangle would comprise lateral fibres which were not properly bound into the twisted thread. In recent times, a so-called condensing zone has been arranged downstream of the drafting unit in order to avoid this disadvantage, in which condensing zone the drafted, but still twist- free fibre strand is bundled or condensed by means of lateral gathering of its single fibres, so that with the application of a further nipping line, the disadvantageous spinning triangle is no longer present. When the fibre strand, condensed in this way, then subsequently receives its spinning twist, a thread is produced which is less hairy, smoother and more tear-resistant. A spinning machine of the above mentioned type is prior art in German published patent application 199 03 113. The suction tube, extending over a plurality of spinning stations, for example one machine section, has a kidney-shaped cross section and extends into the wedge-shaped gap formed by the front roller pair. One reinforcement per spinning station is provided on the suction tube in the form of a thin metal foil measuring between 0.2 and 0.5 mm, whereby the suction slit of each spinning station located in the suction tube also extends through the metal foil. The surfaces of the metail foil thus form the sliding surfaces in the condensing zones, which sliding surfaces follow the outer contour of the suction tube, but at a very slight distance therefrom. It has been shown to be practical when the sliding surfaces of the individual condensing zones begin directly in the wedge-shaped gaps of the front roller pairs. In the known spinning machine, there is, however, the disadvantage that even between two spinning stations, where no reinforcement is present, the suction tube also extends directly to the respective front bottom cylinder due to the thinness of the metal foil. This results in fibres, which for some reason were not bound into the fibre strand during condensing, being able to collect especially between the individual spinning stations. These stray single fibres can get, unwanted, into the fiber strand and/or can block the perforations of the air-permeable transport belt, which in time impairs the condensing effect. It is an object of the present invention, in a spinning machine of the above mentioned type, to remove stray fibres located between two spinning stations in an easy way. This object has been achieved in accordance with the present invention in that the suction tube is arranged at a distance from the front roller pairs and that the sliding surfaces comprising the suction slits are housed in single housings attached to the suction tube, which single housings bridge over the gap between the suction tube and the wedge-shaped gaps. This embodiment now provides a sufficiently large intermediate space between the suction tube and the front bottom cylinder. As a result of the large cleaning gap which occurs, stray fibres can fall through and thus be removed from the critical area, for example, by a travelling cleaner This feature of the present invention results in a sufficiently large clearance between the spinning stations, which feature aids the cleaning function. The single housings can be made compeletly from plastics and slid onto the suction tube, which is designed as a basic round tube. The housings must, however, be secured against lateral movement and rotation. Lateral guiding surfaces are applied to each individual housing for the respective transport belt. This has the advantage that the transport belt is exactly laterally guided in the actual condensing area. The suction tube is advantageously provided with relatively large suction openings in the individual spinning stations, which suction openings are covered after the single housings have been assembled and which act with the suction slits applied in the single housings. No great tolerances are required for the suction openings in the suction tube, while the technically significant suction slits located in the sliding surfaces can be applied to the single housings in a simple way during manufacture. The single housings can be designed as hollow profiles which are provided with lateral covers. The bore holes, with which the single housings are slid onto the suction tube, are then located in the covers. In this way the necessary sealing between the suction tube and the single housings is achieved. In an embodiment of the present invention an idler pulley can be arranged to each single housing, which idler pulley is driven by a friction roller. This type of drive transfefs sufficient friction to the transport belt, without the transport belt being subjected to unusually great wear. A nipping roller, bordering the condensing zone on its exit side, which drives the transport belt as in the above mentioned prior art, no longer serves the drive function, but rather only the twist block between the condensing zone and the twisting element. BRIEF DESCRIPTION OF THE DRAWINGS These and further objects, features and advantages of the present invention will become more readily apparent from the following detailed description thereof when taken in conjunction with the accompanying drawings wherein: Figure 1 is a partly intersectional side view of a spinning station of a spinning machine in the area of a condensing zone, Figure 2 is a view in the direction of the arrow II of Figure 1 of the area of the condensing zone, whereby several components, in particular pressure rollers located above the condensing zone, have been omitted. DETAILED DESCRIPTION OF THE DRAWINGS In the case of the sections of the spinning machine shown in Figures 1 and 2, a ring spinning machine is preferably involved. The spinning machine comprises in the usual way a plurality of spinning stations arranged adjacently in machine longitudinal direction, of which three spinning stations 1, 2 and 3 can be seen in Figure 2. Each spinning station 1,2,3 comprises a drafting unit 4, of which only the end area is shown in Figure 1, and also comprises a condensing zone 6 which bundles a drafted, but still twist- free fibre strand 5, and which condensing zone 6 is located downstream of the drafting unit 4. The remaining components of the spinning stations 1,2, 3 are not shown. Each drafting unit 4 comprises a front roller pair 7, as well as an apron roller pair 10, arranged upstream therefrom, which guides a bottom apon 8 and an upper apron 9. The remaining roller pairs of the drafting unit 4 are not shown. The front roller pair 7 comprises a driven bottom cylinder 11, which extends along a plurality of spinning stations 1,2 3......which driven bottom cylinder 11 has, in the known way, a corrugated area 12. At each spinning station 1, 2, 3 .... a pressure roller 13 is arranged to the corrugated area 12 of the bottom cylinder 11. The front roller pair 7 defines a front nipping line 14, at which the drafting zone of the drafting unit 4 comes to an end. In the drafting unit 4, fed fibre material 15, for example a sliver or a roving, is drafted in the known way in transport direction A to the desired degree of fineness. The drafting process is essentially finished at the front nipping line 14. For the reasons mentioned above, a condensing zone 6 is arranged downstream of the drafting unit 4, in which condensing zone 6 the still twist-free fibre strand 5 is bundled or condensed by means of lateral gathering of its single fibres. Each condensing zone 6 comprises an air-permeable transport belt 16, which transports the fibre strand 5 to be condensed through the condensing zone 6. In the case of the transport belt 16, a thin, close-meshed woven belt is preferably involved here, which gives rise for obvious reasons to the air-permeability. Each transport belt 16 is guided over a sliding surface 17, which, in detail to be described below, is formed by the outer contour of a single housing 18, which single housing 18, together with further single housings 18, are arranged on a suction tube 19 which extends along a plurality of spinning stations 1,2,3. Low pressure prevails in the suction tube 19, which is connected via a low pressure conduit 20 to a low pressure source (not shown). A suction slit 21 is located in the sliding surface 17 of each spinning station 1,2, 3......which suction slit 21 is arranged slightly transversely to the direction of motion of the respective transport belt 16 and as a result of which is provided with a lateral fibre guiding edge 22, along which the fibre strand 5 to be condensed travels. On this fibre guiding edge 22, the fibre strand 5 is condensed by means of lateral gathering of its single fibres, whereby in addition a very slight false twist is applied which increases the condensing effect. The transport belt 16 is guided at a distance from the suction slit 21 over a deflecting guide 23 in the form of a tension roller. At the end of each condensing zone 6, a nipping roller 24 is arranged, which, together with the respective sliding surface 17, forms a delivery nipping line 25, to which the suction slit 21 extends and which forms a twist block in relation to the spinning twist. Directly downstream of the delivery nipping line 25, the thread 26 is produced, whereby it is fed in delivery direction B to a twist element (not shown), for example a ring spindle. The nipping roller 24 prevents the spinning twist in the thread 26 retroacting back into the condensing zone 6. The driven bottom cylinder 11 as well as the remaining bottom cylinders (not shown or denoted) of the drafting unit 4 extend in the usual way in longitudinal direction of the spinning machine and are supported in drafting unit stands (not shown) which are arranged at practical intervals. The deflecting roller 23 is arranged in direct proximity to the bottom roller 11 and forms with same a wedge-shaped gap 27. A friction roller 28 is located in this wedge-shaped gap 27, which friction roller 28 is also supported in the drafting unit stands, thus being disposed, spring-mounted, at both the bottom roller 11 and the deflecting roller 23. The friction roller 28 is driven hereby by the bottom cylinder 11 and drives in turn by means of friction the deflecting guide 23 and simultaneously the transport belt 16. For this purpose, the friction roller 28 is provided with a suitable coating. As can be seen in particular in Figure 1, there are two components moving simultaneously at the point of the friction drive, namely the friction roller 28 and the deflecting roller 23. For this reason, the transport belt 16 shows practically no wear, despite the heavy pressure required for the friction drive. The nipping roller 24, which is turn driven by the transport belt 16, need only be pressed against the sliding surface 17 in the area of the delivery nipping line 25 with enough force to ensure the desired twist block effect. As can be seen in particular in Figure 1, the front roller pair 7 forms, on its side facing the condensing zone 6, a wedge-shaped gap 29, into which the individual sliding surfaces 17 project. Each sliding surface 17 should be positioned as near as is technically possible to the front nipping line 14 and to the bottom cylinder 11 without actually touching the latter and without deflecting to any great degree the fibre strand 5 to be condensed in the area of the wedge-shaped gap 29. It has been shown, that a placement of the parts of this kind results in a particularly good quality of the thread 26. The close positioning should be such that between the respective sliding surface 17 and the relevant front nipping line 14 and the bottom cylinder 11 only a very slight gap remains . Positioning the sliding surface 17 to the front roller pair 7 helps prevent stray fibres occuring, which then leave the fibre strand 5. Should any stray fibres occur, they must be prevented from reaching the fibre strand 5 again in an undesired way. For this reason, a feature of the present invention provides that between any two spinning stations 1,2,3..... there is a sufficiently large gap 30 between the bottom cylinder 11 and the suction tube 19. This gap 30 is large enough for any stray fibres to fall through easily, and to thus be removed from the critical area between two spinning stations 1,2,3. The cleaning effect can be increased when the bottom cylinder 11 come into contact with the transport belt 16 at a point 31, where the bottom cylinder 11 and the transport belt 16 travel in opposite directions to one another. This provides an additional mechanical cleaning means for cleaning the transport belt 16. As already mentioned, the suction tube, extending along a plurality of spinning stations 1,2 3 in the machine according to the prior art, is designed in such a way that it extends to the wedge-shaped gap 29. This is not the case in the embodiment of the present invention. According to the Figures 1 and 2 a single housing 18 is provided for each spinning station 1,2,3 ..., which single housing 18 comprises the respective sliding surface 17 having a suction slit 21, and which single housing 18 is slid onto the suction tube 19 extending along a plurality of spinning stations 1,2,3......The single housings 18 are designed as hollow profiles 32 having lateral covers 33,34. Bore holes are located in these covers 33,34, the diameter of said bore holes being adapted to the diameter of the suction tube 19. Thus a sealing can be achieved at the same time between the suction tube 19 and the respective single housing 18. Because the individual sliding surfaces 17 are arranged to single housings 18, the suction tube 19 can be arranged at a distance from the front roller pairs 7. The single housings 18, containing the sliding surfaces 17 with the suction slits 21, bridge the gap between the suction tube 19 and the wedge-shaped gaps 29, which is not the case in prior art. This results in a relativing large gap 30 between two respective spinning stations 1,2,3......which gap 30 is bordered by the bottom cylinder 11 on the one side and on the other by the suction tube 19. This large gap 30 serves to keep the spinning machine clean between the spinning stations 1,2,3 ..... so that stray fibres cannot get into the condensed fibre strand 5 in an undesired way. The single housings 18 are advantageously made of plastic and can therefore be provided in a simple way with lateral guiding edges 35 and 36 for guiding the transport belt 16, in particular in the area of the condensing zone 6. The suction tube 19 is provided in the area of the individual spinning stations 1,2,3 with relatively wide suction openings 37, which in their dimensions have wide tolerances. These suction openings 37 are covered in a sealed way by the respective single housings 18 during assembly onto the suction tube 19 and act together with the individual suction slits 21 located in the single housings 18. The suction slits 21 located in the sliding surfaces 17 are more closely tolerated and are adapted to the special requirements of the condensing process. ME CLAIM: 1. A spinning machine having a plurality of spinning stations arranged adjacent to one another, which each comprise a drafting unit having a front roller pair which forms a front nipping line as well as a condensing zone arranged downstream thereof which condenses a drafted fibre strand, which condensing zone comprises an air - permeable transport belt which transports the fibre strand, and which transport belt is guided on a sliding surface comprising a suction slit, whereby the sliding surfaces for a plurality of transport belts are arranged on a suction tube extending over a plurality of spinning stations* and which project into the wedge-shaped gap formed by the respective front roller pair, characterized in that the suction tube (19) is arranged at a distance from the front roller pairs (7), and in that the sliding surfaces (17) with the suction slits (21) are arranged in single housings (13) attachable to the suction tube (19), which single housings (18) bridge the gap between the suction tube (19) and the wedge-shaped gaps (29). 2. A spinning machine as claimed in claim 1, wherein the single housings (18) are provided with lateral guiding surfaces (35,36) for the respective transport belt (16). 3. A spinning machine as claimed in claims 1 or 2, wherein the suction tube (19) is provided at the individual spinning stations (1, 2,3....) with suction openings (37), which are covered by the single housings (18) and which act together with the individual suction slits (21). 4. A spinning machine as claimed in any of the claims 1 to 3, wherein the single housings (13) are designed as hollow profiles (32) having lateral covers (33, 34). 5. A spinning machine as claimed in any of the claims 1 to 4, wherein a deflecting roller (23) which guides the transport belt (16) is arranged to each single housing (18), which deflecting roller (23) is driven by a friction roller (28). 6. Condensing apparatus for a spinning machine having a plurality of spinning positions (1,2,3....) arranged adjacent to each other and each having a drafting unit (4) comprising a front roller pair (7) may be arranged downstream from the front roller pair (7) of a spinning position (1,2,3) for forming a condensing zone (6), said condens- ing apparatus comprising a sliding surface (17) provided with a suction slit (21) for slidingly supporting an air-permeable transport belt (16) for transporting a drafted fibre strand (5) leaving the front roller pair (7) of said drafting unit (4), characterized by comprising : a suction tube (19) having a length sufficient for extending over several spinning positions (1,2,3) and which suction tube (19) is provided with individual housings (18) for individual spinning positions (1,2,3) which housings (18) extend from the suction tube (21) toward the front roller pair (7) of a spinning position (1), which housings (18) form the sliding surface (17) for the transport belt (16) and which housings (18) are provided with the suction slit (21). The invention relates to a spinning machine having a plurality of spinning stations arranged adjacent to one another, which each comprise a drafting unit having a front roller pair which forms a front nipping line as well as a condensing zone arranged downstream thereof which condenses a drafted fibre strand, which condensing zone comprises an air - permeable transport belt which transports the fibre strand, and which transport belt is guided on a sliding surface comprising a suction slit, whereby the sliding surfaces for a plurality of transport belts are arranged on a suction tube extending over a plurality of spinning stations, and which project into the wedge- shaped gap formed by the respective front roller pair. The suction tube (19) is arranged at a distance from the front roller pairs (7), and in that the sliding surfaces (17) with the suction slits (21) are arranged in single housings (18) attachable to the suction tube (19), which single housings (18) bridge the gap between the suction tube (19) and the wedge—shaped gaps (29).

Documents:

00035-cal-2002-abstract.pdf

00035-cal-2002-assignment.pdf

00035-cal-2002-claims.pdf

00035-cal-2002-correspondence.pdf

00035-cal-2002-description (complete).pdf

00035-cal-2002-drawings.pdf

00035-cal-2002-form 1.pdf

00035-cal-2002-form 18.pdf

00035-cal-2002-form 2.pdf

00035-cal-2002-form 26.pdf

00035-cal-2002-form 3.pdf

00035-cal-2002-form 5.pdf

00035-cal-2002-letter patent.pdf

00035-cal-2002-priority document others.pdf

00035-cal-2002-reply f.e.r.pdf