Title of Invention | AN IMPROVED TRANSPORT BELT FOR TRANSPORTING A FIBRE STRAND TO BE PNEUMATICALLY CONDENSED |
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Abstract | A transport belt for transporting a fibre strand to be pneumatically condensed comprises, at least in one area in which the fibre strand is guided, of an air-permeable woven material made of synthetic filaments. A percentage of these synthetic filaments is provided with an electroconductive surface, while a further percentage of the synthetic filaments is provided with a fat-repellent surface. The synthetic filaments having a fat-repellent surface and the synthetic filaments having an electroconductive surface can be arranged alternately. Equally possible is the arrangement of more synthetic filaments in the area in which the fibre strand is guided, while more synthetic filaments having an electroconductive surface are arranged adjacently to the fibre strand guiding area. |
Full Text | BACKGROUND AND SUMMARY OF THE INVENTION Transport belt for transporting a fibre strand The present invention relates to a transport belt for transporting a fibre strand to be pneumatically condensed , said transport belt consisting at least in an area which guides the fibre strand of an air-permeable woven material made of synthetic filaments, and whereby a percentage of the synthetic filaments is provided with an electroconductive surface. When a drafted fibre strand is imparted a spinning twist directly downstream of the front roller pair of the drafting unit, a so-called spinning triangle occurs at the nipping line of the front roller pair. This comes about because the drafted fibre strand leaves the drafting unit having a certain width and is twisted to a thread having a relatively small diameter. The spinning triangle comprises lateral fibres, which are not properly bound into the twisted thread and thus contribute little or nothing to the tensile strength of the spun thread. In recent times, a condensing zone has been arranged downstream of the drafting zone of the drafting unit, which condensing zone is in turn bordered by a nipping line. Only downstream thereof is the thread imparted its spinning twist. The fibres are bundled or condensed in the condensing zone, whereby the fibre strand is so narrow when it leaves the nipping line furthest down- stream that the feared spinning triangle is no longer noticeably disadvantageous. The spun thread is then more even, tear-resistant and less hairy. A wide range of arrangements for condensing a fibre strand are known. Many of these function with an air-permeable transport belt, which transports the fibre strand to be condensed slidingly over a suction slit. An arrangement of this type is disclosed in German published patent application 199 11 333. It should be mentioned here that in the terminology of this patent application the term "pneumatic condensing" also includes those arrangements in which, apart from the suction airstream, a further means, such as a transport component against a slantingly positioned suction slit, also acts in and has an effect on the condensing process. A transport belt of the above type is prior art in German published patent application 10 2004 005 953. By means of the electroconductive surface of the synthetic filaments, either the transport belt is prevented at the outset from being electrostatically charged, or such electrostatic charges are reduced by means of charge dissipation to a level harmless in practical application. The adherence of fibre fly on the transport belt caused by electrostatic charges ceases to a great extent. Contamination of such transport belts cannot, however, be completly prevented hereby, as the fibre materials to be processed also contain to a certain degree strongly adhering impurities, for example wool fat or honeydew. These strongly adhering impurities are deposited over time on the transport belt and reduce the condensing effect of the arrangement, as the air-permeability of the transport belt lessens. As this a slow process, it is particularly dangerous as the decline in the condensing effect is often only noticed at a late stage. It is an object of the present invention to create an improved transport belt for the pneumatic condensing process of a fibre strand which has a reduced tendency to become contaminated. This object has been achieved in accordance with the present invention in that a percentage of the synthetic filaments has a fat-repellent surface. This prevents the depositing of those strongly adhering impurities, which are not influenced by a reduced electrostatic charge. The air-permeability of the woven material is thus maintained for a significantly longer period of time. Synthetic filaments with a fat-repelling surface can be produced in a variety of ways. Particularly advantageous is a coating of the synthetic filaments with polytetrafluoroethylene (also known under the brand name of Teflon) or with a mixture of materials thereof. The synthetic filaments having an electrocondutive surface are advantageously metallized synthetic filaments, where the synthetic filaments are provided with a metal coating. Advantageously the synthetic filaments having a fat-repelling surface and the synthetic filaments having an electroconductive surface are alternately arranged. Both properties are thus optimally combined. It can be provided, however, that more synthetic filaments having a fat-repellent surface can be placed in the area guiding the fibre strand. Thus that area in particular, in which the largest deposits of these impurities occur, is protected against said impurities. The strongly adhering impurities impurities are namely, in the main, released from the fibre strand to be condensed and taken up by the transport belt. In order to guarantee a sufficient electrostatic dissipation of the entire transport belt, it can be advantageous to place the synthetic filaments having an electroconductive surface in greater numbers adjacent to the area which guides the fibre strand. The transport belt is particularly advantageous designed as a endless woven sieve belt. 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 shows an arrangement for condensing a drafted, still twist-free fibre strand, for which the transport belt of the present invention can be applied, Figure 2 is a view in the direction of the arrow II of Figure 1, whereby the individual rollers have been omitted for the purposes of greater clarity. Of a spinning machine, in particular a ring spinning machine, only the area of an arrangement 1 for condensing a drafted but still twist-free fibre strand 2 is shown in Figures 1 and 2. The arrangement 1 is located directly downstream of a drafting unit 3, of which only the front roller pair 4, as well as an apron roller pair having a lower apron 6 and a top apron 7 and being arranged upstream of the front roller pair 4, are shown. The front roller pair 4 comprises a driven front bottom roller 8 as well as a front pressure roller 9 flexibly pressed thereagainst. The front roller pair 4 defines a front nipping line 10, which forms the end of the drafting zone of the drafting unit 3. In the drafting unit 3, a sliver or a roving 11 is drafted in transport direction A to the desired degree of fineness in the known way. The drafting process ends at the front nipping line 10 and from this point on the drafted but still twist-free fibre fibre strand 2 is formed. In order to reduce the known and disadvantageous spinning triangle, the fibre strand 2 is condensed directly downstream of the front nipping line 10 in a condensing zone 12. The arrangement 1 provided for the condensing comprises an air-permeable transport belt 13, which transports the fibre strand 2 to be condensed through the condensing zone 12. The arrangement 1 comprises further a suction channel 14, which is designed as a hollow profile in which a vacuum prevails, and which can extend over a plurality of spinning positions. The suction channel 14 is designed on its side facing the condensing zone 12 as a sliding surface 15 for guiding the transport belt 13. In the sliding surface 15 a suction slit 16 is located, which is arranged slightly diagonally to the direction of motion of the transport belt 13, so that one lateral edge of the suction slit 16 is designed as a fibre guiding edge 17 in relation to the fibre strand 2 to be condensed. The fibre strand 2 travels along this fibre guiding edge 17 during the condensing process, whereby the fibres in the fibre strand 17 are bundled or condensed transversely to the direction of motion of the transport belt 13, during which the fibre strand 2 is rolled in somewhat. The suction channel 14 is connected via a vacuum conduit 18, which is located at a distance from the suction slit 16, to a vacuum source (not shown). Insofar as the suction channel 14 extends over a plurality of spinning positions, only one vacuum conduit 18 needs to be present per suction channel 14. The condensing zone 12 is bordered on its exit side by a nipping roller 19, which presses the fibre strand 2 and the transport belt 13 onto the sliding surface 15 and thereby defines a delivery nipping line 20, which functions as a twist block with regard to the spinning twist to be applied. The nipping roller 19 drives the transport belt 13 and is in turn driven by the front pressure roller 9 via a transfer wheel 21, for example, in the form of a toothed wheel. Downstream of the delivery nipping line 20 the forming thread 22 receives its spinning twist, in that it is fed in delivery direction B to a twist device (not shown), for example a ring spindle. The delivery nipping line 20 functions as a twist block in regard to the spinning twist, so that the spinning twist does not extend back into the condensing zone 12. On the side of the suction channel 14 facing away from the suction slit 16, the transport belt 13 is tensioned by means of a tensioning element 23, which can be designed as a stationary rod or also as a guiding roller. The tensioning element 23 is hereby so arranged that the transport belt 13 lies with a light pressure on the front bottom roller 8. As the transport belt 13 and the front bottom roller 8 travel in opposite directions to one another at the point of contact, the transport belt 13 is cleaned of any adhering fibre fly. As can be seen in Figure 2, the initial area 24 of the suction slit 16 comprises an extension which permits the fibre strand 2, traversing slightly in transverse direction to be reliably taken hold of by the suction slit 16. The traverse motion serves in particular to ensure that the front pressure roller 9 has a longer life. As already mentioned, the transport belt 13 consists, in its area which guides the fibre strand 2, of a woven material 25. A number of the synthetic filaments 26 are provided with an electroconductive surface in order to prevent the woven material 25 from becoming electrostatically charged and thus becoming clogged with fibre fly. The fibre material forming the fibre strand 2 can, depending on the mix, contain strongly adhering impurities such as wool fat or honey dew. These can be deposited in the woven material 25 in the area which guides the fibre strand 2. This cannot be prevented solely by synthetic fibres 26 having an electroconductive surface. It is therefore provided according to the present invention that a further number of synthetic filaments 27 have a fat-repellent surface. Clogging of the perforations naturally occuring in the woven material 25 by strongly adhering impurities is thus greatly reduced. In the embodiment shown in Figure 2, the synthetic fibres having an electro- conductive surface 26 are arranged transversely to the direction of transport A of the fibre strand 2. Those synthetic filaments having a fat-repelling surface 27 are arranged parallel to the transport direction A and interlace in the woven material with the synthetic filaments 26 having an electroconductive surface. In an embodiment of the present invention it can, however, be provided that the synthetic filaments 27 having a fat-repelling surface and the synthetic filaments 26 having an electroconductive surface can be arranged alternately adjacent to one another, for example parallel to the direction of transport A. It is also advantageous to arrange numbers of identical synthetic filaments adjacently in groups. For example, in the area which guides the fibres strand 2, synthetic filaments 27 having a fat-repelling surface can be used in increased numbers. The largest amount of strongly adhering impurities occur in this particular area above the suction slit 16, and it is therefore advantageous when the fat-repelling surface is fortified by increased numbers of fat- repelling filaments. In order to ensure the electroconductivity of the transport belt 13, it can be advantageous to place the synthetic filaments 26 having an electroconductive surface in greater numbers adjacent to the area guiding the fib/e strand. CLAIMS: 1. A transport belt (13) for transporting a fibre strand (2) to be pneumatically condensed, said transport belt consisting at least in an area which guides the fibre strand (2) of an air-permeable woven material (25) made of synthetic filaments (26, 27), and whereby a percentage of the synthetic filaments (26) is provided with an electroconductive surface, characterized in that a further percentage of the synthetic filaments (27) have a fat-repelling surface. 2. A transport belt according to claim 1, characterized in that the synthetic filaments (27) having a fat-repelling surface are arranged in increased numbers in the area which guides the fibre strand (2). 3. A transport belt according to claim 1 or 2, characterized in that the synthetic filaments (26) having an electroconductive surface are arranged in increased numbers adjacent to the area which guides the fibre strand (2). 4. A transport belt according to any of the claims 1 to 3, characterized in that the synthetic filaments (27) having a fat-repelling surface and the synthetic filaments (26) having an electroconductive surface are arranged alternately. 5. A transport belt according to any of the claims 1 to 4, characterized in that the synthetic filaments (26) having an electroconductive surface are designed as metallized synthetic filaments. A transport belt for transporting a fibre strand to be pneumatically condensed comprises, at least in one area in which the fibre strand is guided, of an air-permeable woven material made of synthetic filaments. A percentage of these synthetic filaments is provided with an electroconductive surface, while a further percentage of the synthetic filaments is provided with a fat-repellent surface. The synthetic filaments having a fat-repellent surface and the synthetic filaments having an electroconductive surface can be arranged alternately. Equally possible is the arrangement of more synthetic filaments in the area in which the fibre strand is guided, while more synthetic filaments having an electroconductive surface are arranged adjacently to the fibre strand guiding area. |
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170-KOL-2006-AMENDED CLAIMS.pdf
170-KOL-2006-ASSIGNMENT.1.3.pdf
170-KOL-2006-CORRESPONDENCE-1.1.pdf
170-KOL-2006-CORRESPONDENCE-1.2.pdf
170-KOL-2006-CORRESPONDENCE.1.3.pdf
170-kol-2006-correspondence.pdf
170-KOL-2006-DESCRIPTION (COMPLETE).1.1.pdf
170-kol-2006-description (complete).pdf
170-KOL-2006-EXAMINATION REPORT REPLY RECIEVED.pdf
170-KOL-2006-EXAMINATION REPORT.1.3.pdf
170-KOL-2006-EXAMINATION REPORT.pdf
170-KOL-2006-GRANTED-ABSTRACT.pdf
170-KOL-2006-GRANTED-CLAIMS.pdf
170-KOL-2006-GRANTED-DESCRIPTION (COMPLETE).pdf
170-KOL-2006-GRANTED-DRAWINGS.pdf
170-KOL-2006-GRANTED-FORM 1.pdf
170-KOL-2006-GRANTED-FORM 2.pdf
170-KOL-2006-GRANTED-LETTER PATENT.pdf
170-KOL-2006-GRANTED-SPECIFICATION.pdf
170-KOL-2006-OTHERS DOCUMENTS.pdf
170-KOL-2006-PETITION UNDER RULE 137.pdf
170-kol-2006-priority document.pdf
170-KOL-2006-REPLY TO EXAMINATION REPORT.1.3.pdf
170-KOL-2006-REPLY TO EXAMINATION REPORT.pdf
170-kol-2006-specification.pdf
170-kol-2006-translated copy of priority document.pdf
Patent Number | 247839 | ||||||||
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Indian Patent Application Number | 170/KOL/2006 | ||||||||
PG Journal Number | 21/2011 | ||||||||
Publication Date | 27-May-2011 | ||||||||
Grant Date | 25-May-2011 | ||||||||
Date of Filing | 24-Feb-2006 | ||||||||
Name of Patentee | MASCHINENFABRIK RIETER AG | ||||||||
Applicant Address | KLOSTERSTRASSE 20, 8406 WINTERTHUR | ||||||||
Inventors:
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PCT International Classification Number | N/A | ||||||||
PCT International Application Number | N/A | ||||||||
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PCT Conventions:
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