Title of Invention	METHOD AND DEVICE FOR THE PRODUCTION OF CORE YARN
Abstract	In a method for producing core yarn (1) from a core thread (2) and a sliver (3) which are joined together by twisting the sliver (3) around the core thread (2), the sliver (3) should be compacted before combining with the core thread (2). The sliver (3) is traversed during compacting.

Full Text

FORM 2 THE PATENTS ACT, 1970 (39 of 1970) COMPLETE SPECIFICATION (See Section 10; rule 13) TITLE METHOD AND DEVICE FOR THE PRODUCTION OF CORE YARN APPLICANT MASCHINENFABRIK RIETER AG Klosterstrasse 20 CH-8406 Winterthur Switzerland Nationality: a Swiss company The following speciflcation particularly describes the nature of this invention and the manner in which it is to be performed 02.02.2006 We/ps-3081A/E 1 METHOD AND DEVICE FOR THE PRODUCTION OF CORE YARN The invention relates to a method for the production of core yarn from a core thread and a sliver which are joined to one another by twisting the sliver around the core thread, as well as a device herefor. PRIOR ART In the case of core yarn, during the formation of the yarn, especially during its drafting to a desired fineness and its bonding, a core thread is laid into a sliver by twisting and the fibres are spun around it. This takes place until the core thread disappears in the sliver. The core thread substantially determines the strength and the elongation of the yarn produced whereas the sliver determines the feel and the appearance of the yarn. An endless synthetic thread can be used as the core thread, for example whereas staple fibres of cotton or wool are usually used as sliver. It is known from EP 0 635 590 B1 that a core thread is introduced directly into the pair of withdrawal rollers of a drafting device. This thread together with the sliver runs through the fibre bundling zone between the pair of withdrawal rollers and a pair of delivery rollers in which the fibres are already laid on the endless threads as a result of the amalgamation and then on leaving the pair of delivery rollers, are twisted together to form a thread of core yarn. This means that the core thread and the sliver are already brought together before the compacting device so that the compaction of the sliver is disturbed by the core thread. Furthermore traversing of the sliver to achieve uniform wear on the rollers is not possible. The problem of traversing is addressed in EP 0 986 659 B1 wherein a core-thread thread guide must be centred with respect to the roving inlet funnel of a drafting frame so that the core thread always runs centrally to the sliver. This position must be maintained during traversing of the sliver. For this purpose roving inlet funnel and core-thread thread guide are mechanically coupled. In this device however, the combination 02.02.2006 We/ps-3081A/E 2 of core thread and sliver likewise enters into the compaction device combined so that that no further traversing of the sliver can take place there and the compaction of the sliver is hindered by the core thread. It is known from DE-OS 102 36 450 to combine two compacted slivers running towards each other with at least one core yarn, where the core yarn can be traversed. In practice, the sliver is guided over a compaction device uniquely oriented in the direction of transport so that no lateral displacement takes place during compaction. The core thread is guided in the same plane as that in which the sliver runs. Good yarn values are achieved as a result of these conditions but increased wear can occur on the rollers with which the sliver comes in contact. OBJECT It is the object of the present invention to obviate the aforementioned disadvantage, SOLUTION OF THE OBJECT This object is solved by a method according to claim 1 and/or a device having the features of claim 7. This means that the sliver is supplied separately from the core thread to the compaction device with a traversing movement and is preferably only combined with the core thread at the end of the compaction process or thereafter. The sliver should preferably be traversed before the compaction. On the one hand, the compaction of the sliver is hereby improved and on the other hand, it is ensured that the sliver does not run into the surface of guide rollers which can otherwise result in 02.02.2006 We/ps-3081A/E 3 impermissible wear of the guide rollers. The lifetime of the guide rollers is considerably increased as a result. The core thread is preferably guided stationarily, wherein however a traversing of the core thread should also be covered by the invention. The sliver is guided approximately parallel next to the core thread in the compaction device and especially in the compacting zone formed in front of the compaction device, If, in a preferred exemplary embodiment, the compaction zone has a suction slit, the sliver is substantially guided over this suction slit and traversed over the width of the suction slit. The sliver and the core thread are preferably only combined with one another towards the end of the suction slit or thereafter. A device for carrying out the method according to the invention has a compaction device with a suction slit. This suction slit has edges or a gathering edge which runs at an inclination to the running direction of the core thread. In particular, the suction slit is constructed as a curved wedge shape and tapered in the running direction of the core thread. The method according to the invention and the corresponding device can be provided not only when setting up spinning machines from new but also already existing spinning machines can be fitted with the device according to the invention and operated using the method according to the invention. DESCRIPTION OF FIGURES The invention is described in detail with reference to the following drawing; this shows in Figure 1 a partial side view of a section from a device according to the invention for producing core yarn; Figure 2 is a schematic plan view of a part of the device according to Figure 1. 02.02.2006 We/ps-3081A/E 4 According to Figures 1 and 2, a core yarn 1 is produced from a core thread 2 and a sliver 3. The core thread 2 is supplied via a feed roller 4 to a compaction device which in the present exemplary embodiment is followed by a drafting frame or is part of this drafting frame. This substantially consists of a roller 5 with an evacuable interior 6, where a compacting zone 8 is formed on a casing 7. This compacting zone 8 has a suction slit 9 which is constructed as curved wedge-shaped, i.e. it has a decreasing width in the running direction x of the core thread 2, a gathering edge 10 also running in a curved fashion towards the core thread 2. The compacting zone 8 is delimited by a nip line 11 of an upper delivery roller 12 and a nip line 13 of an upper nip roller 14. Associated with the upper delivery roller 12, which also has the core thread 2 partly looped around it, is a pair of rollers 15 and 16 each having an apron guide 17 and 18. The sliver 3 is supplied to the compacting zone 8 between the corresponding aprons 19 and 20. The core thread 2 is preferably guided onto the sliver 2 via a guide 21, as shown by the dashed line, or directly via an upper nip roller 14. The mode of operation of the present invention is as follows: The perforated roller 5 and the interior 6 are designated as compaction device 24. The core thread 2 is, for example, supplied via the feed roller 4 and a stationary filament feed 21 to the compacting zone 8, said thread running through the intermediate space between the upper delivery roller 12 and roller 5. In the compacting zone 8 said thread runs at the edge of the suction slit 9 and towards the end of the suction slit 9 it can come close to its suction area. 02.02.2006 We/ps-3081A/E 5 The sliver 3 is supplied to the compacting zone 8 parallel to the core thread 2, where it likewise runs through the intermediate space between upper delivery roller 12 and roller 5. After the corresponding nip line 11 the sliver 3 lies over the broader beginning region of the suction slit 9 and then runs along the gathering edge 10 towards the core thread 2 as a result of the suction and compacting effect, where it is combined with the core thread 2 by twisting towards the end of the suction slit 9 or thereafter. This combining preferably takes place directly before the nip line 13. After the nip line 13 another twist can be imparted to the core thread/sliver so that the sliver winds around the core thread. According to the invention it is provided that the sliver 3 is traversed with the core thread 2 before the combining which is indicated by the double arrow 22. This ensures that the surface of the rollers 5, 12 or the aprons 19 and 20 do not undergo concentrated wear but are worn over a wider area which increases their life. Furthermore, the compacting of the fibre material is not disturbed by the separation of the core thread from the sliver in the compacting zone 8. A traversing device 22 for the sliver is preferably arranged before the inlet into a drafting frame 15, 16, that is before feed rollers into the drafting frame not shown in the diagram and this traversing device is used to move the sliver to and fro transverse to the plane of the drawing in Figure 1. The device for producing core yarn 1 from a core thread 2 and a sliver 3 which can be joined together by twisting the sliver 3 around the core thread 2, wherein a feed roller 4 for the core thread 2 and a pair of rollers 15, 16 are mounted in front of a compaction device comprising a suction slit 9, and a further pair of rollers 5, 12 is preferably mounted thereafter, is thus characterised in that the suction slit 9 runs at an inclination to the running direction x of the core thread 2 and that a traversing device is provided for the sliver 3. The sliver 3 is guided onto the core thread 2 during compaction and is only combined therewith after the compacting. 02.02.2006 We/ps-3081A/E 6 In the device for producing core yarn 1 from a core thread 2 and a sliver 3 which can be joined together by twisting the sliver 3 around the core thread 2, wherein a feed roller 4 for the core thread 2 and a pair of rollers 15, 16 are mounted in front of a compaction device comprising a suction slit 9, and a further pair of rollers 5, 12 is preferably mounted thereafter, the suction slit 9 runs at an inclination to the running direction x of the core thread 2 and a traversing device 22 is provided for the sliver 3.

Documents:

521-CHE-2006 AMENDED CLAIMS 20-10-2014.pdf

521-CHE-2006 AMENDED PAGES OF SPECIFICATION 20-10-2014.pdf

521-CHE-2006 FORM-1 20-10-2014.pdf

521-CHE-2006 POWER OF ATTORNEY 20-10-2014.pdf

521-CHE-2006 CORRESPONDENCE OTHERS 04-06-2014.pdf

521-CHE-2006 CORRESPONDENCE OTHERS 15-07-2014.pdf

521-CHE-2006 ENGLISH TRANSLATION 04-06-2014.pdf

521-CHE-2006 EXAMINATION REPORT REPLY RECIEVED 20-10-2014.pdf

521-CHE-2006 FORM-18.pdf

521-CHE-2006 FORM-3 15-07-2014.pdf

521-che-2006-abstract.pdf

521-che-2006-claim.pdf

521-che-2006-correspondance-others.pdf

521-che-2006-description(complete).pdf

521-che-2006-diagrams.pdf

521-che-2006-form 1.pdf

521-che-2006-form 26.pdf

521-che-2006-form 3.pdf

521-che-2006-form 5.pdf

521-CHE-2006_POR.pdf