Title of Invention

A DEVICE IN A SPINNING MACHINE FOR CONDENSING A FIBRE STRAND

Abstract

A device in a spinning machine for condensing a fibre strand comprising a condensing zone arranged downstream of a drafting zone of a drafting unit, comprising an air-permeable transport belt which transports the fibre strand through the condensing zone, a suction channel arranged to the condensing zone, a reinforced sliding surface for guiding the transport belt arranged to the suction channel, a suction slit arranged in the sliding surface, a nipping roller having a nipping line at the end of the suction slit, which nipping roller presses the fibre strand to the transport belt and the transport belt on the sliding surface, characterized in that the sliding surface (17) is formed partly by the outer contour (23) of an exchangeable insert inserted into the suction channel (15), said outer contour (23) extending flush with the outer surface (22) of the suction channel (15), said insert (21) surrounding the suction slit (18) completely and extending at least in the area of the nipping line (13) over the entire effective width of the nipping roller (19).

Full Text

BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates to a device in a spinning machine for condensing in fibre strand comprising condensing zone arranged downstream of a drafting zone of a drafting unit, also comprising an air-permeable transport belt which transports the fibre strand through the condensing zone, also comprising a suction channel arranged to the condensing zone, comprising a reinforced sliding surface for guiding the transport belt arranged to the suction channel) comprising a suction slit arranged in the sliding surfaces also comprising a nipping roller having a nipping line at the end of the suction slit, which nipping roller presses the fibre strand to the transport belt and the transport belt to the sliding 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 contributes little or nothing to the tensile strength of the spun thread. In recent times, a condensing zon« has arranged downstream of the drafting zone of a 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 downstream that the feared spinning triangle does not occur. The spun thread is then more even, tear-resistant and less hairy. A device of the above mentioned type for condensing a fibre strand is prior art in German published Patent applicat- ion 199 03 113. In this device, the sliding surface of the suction channel is formed by a thin metal foil« which has a frame-like recess adapted to the contours of the suction slit, which recess is somewhat smaller than the suction slit. The metal foil can be designed as an open metal sheet having two points of impact which are located outside of the sliding surface. Tha width of the metal foil corresponds to the width of the transport belt. The known suction channel extands along a plurality of spinning stations and comprises one metal foil as described above per spinning station. These metal foils have to be replaced from time to time due to wear. When a metal foil is to be replaced in the known device, the suction channel has to be removed from the machine, and all metal foils subsequently The transport belt, drivsn from the outsid, by the nipping rollers should be permitted to slide on the sliding surface of the suction channel or the insert with as little friction as possible. It is therefore provided that the outer contour of the insert is provided with a structure which lessens the friction between the insert and the transport belt. This can be a very slight ribbing in travel direction of the transport belt, or a waffle-type structure or an orange peel effect. BRIEF DESCRIIPTION OF THE ACCOMPANYING 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 whereim Figure 1 is a partly intersectional side view of a device of the present inventioni Figure 2 is a view in the direction of the arrow II of Figure 1 in the area of the insert. DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS The device 1 for condensing a fibre strand 2 according to Figures 1 and 2 is a component part of a spinning machine, preferably a ring spinning machine. These spinning machines comprise per spinning station a drafting unit 3 (only partly shown) of which only a front roller pair 4 and an apron pair 5,6 arranged upstream thereof are shown. The front roller pair 4 comprises a bottom roller 7 designed as a continuous) driven bottom cylinder extending in machine longitudinal direction, to which bottom roller 7 a pressure roller 8 per spinning station is arranged. The bottom roller 7 and the pressure roller 8 form together a front nipping line 9f which ends the drafting zone of the drafting unit 3. A sliver or a roving 10 is fed in transport direction A to the drafting unit 3 and is drafted to the desired degree of fineness in the drafting unit 3 in the known way. A condensing zone 11 is arranged downstream of the front roller pair 4 of the drafting unit 3, in which condensing zone 11 the drafted, but still twist- free fibre strand 2 is bundled or condensed. The device 1 for this purpose comprises an air-permeable transport belt 12, which transports the fibre strand 2 through the condensing zone 11. The transport belt 12 is advantageously a thin, closed-meshed woven belt made of polyamide threads. The exit end of the condensing zone 11 is bordered by a nipping line 13, which also serves as a twist block, so that the fibre strand 2 remains twist-free in the condensing zone 11. Directly downstream of the nipping line 13 a thread 14 is produced which is fed in delivery WE CLAIM: 1. A device in a spinning machine for condensing a fibre strand comprising a condensing zone arranged downstream of a drafting zone of a drafting unit, comprising an air-permeable transport belt which transports the fibre strand through the condensing zone, a suction channel arranged to the condensing zone, a reinforced sliding surface for guiding the transport belt arranged to the suction channel, a suction slit arranged in the sliding surface, a nipping roller having a nipping line at the end of the suction slit, which nipping roller presses the fibre strand to the transport belt and the transport belt on the sliding surface, characterized in that the sliding surface (17) is formed partly by the outer contour (23) of an exchangeable insert inserted into the suction channel (15), said outer contour (23) extending flush with the outer surface (22) of the suction channel (15), said insert (21) surrounding the suction slit (18) completely and extending at least in the area of the nipping line (13) over the entire effective width of the nipping roller (19). 2. Device as claimed in claim 1, wherein the outer contour (23) of the insert (21) belonging to the sliding surface (17) surrounds a deflecting guide (24) of the suction channel (15) in the area of the front roller pair (4). 3. Device as claimed in claims 1 or 2, wherein the insert (21) extends the length of the suction slit (18) towards the inside of the suction channel (15) by means of the shaft [25). 4. Device as claimed in claim 3, wherein the shaft (25) is more defined in the area of the nipping line (13) than in the area of the deflecting guide (24). 5. Device as claimed in any one of the claims 1 to 4, wherein the outer contour (23) of the insert (21) is provided with a surface structure (26) which reduces the friction between the insert (21) and the transport belt (12). A device in a spinning machine for condensing a fibre strand comprising a condensing zone arranged downstream of a drafting zone of a drafting unit, comprising an air-permeable transport belt which transports the fibre strand through the condensing zone, a suction channel arranged to the condensing zone, a reinforced sliding surface for guiding the transport belt arranged to the suction channel, a suction slit arranged in the sliding surface, a nipping roller having a nipping line at the end of the suction slit, which nipping roller presses the fibre strand to the transport belt and the transport belt on the sliding surface, characterized in that the sliding surface (17) is formed partly by the outer contour (23) of an exchangeable insert inserted into the suction channel (15), said outer contour (23) extending flush with the outer surface (22) of the suction channel (15), said insert (21) surrounding the suction slit (18) completely and extending at least in the area of the nipping line (13) over the entire effective width of the nipping roller (19).

Documents:

IN-PCT-2002-710-KOL-(10-10-2011)-FORM 15.pdf

IN-PCT-2002-710-KOL-(10-10-2011)-OTHER PATENT DOCUMENTS.pdf

IN-PCT-2002-710-KOL-FORM-27.pdf

in-pct-2002-710-kol-granted-abstract.pdf

in-pct-2002-710-kol-granted-assignment.pdf

in-pct-2002-710-kol-granted-claims.pdf

in-pct-2002-710-kol-granted-correspondence.pdf

in-pct-2002-710-kol-granted-description (complete).pdf

in-pct-2002-710-kol-granted-drawings.pdf

in-pct-2002-710-kol-granted-examination report.pdf

in-pct-2002-710-kol-granted-form 1.pdf

in-pct-2002-710-kol-granted-form 18.pdf

in-pct-2002-710-kol-granted-form 2.pdf

in-pct-2002-710-kol-granted-form 3.pdf

in-pct-2002-710-kol-granted-form 5.pdf

in-pct-2002-710-kol-granted-pa.pdf

in-pct-2002-710-kol-granted-reply to examination report.pdf

in-pct-2002-710-kol-granted-specification.pdf

in-pct-2002-710-kol-granted-translated copy of priority document.pdf