Title of Invention

WEAVING MACHINE, PARTICULARLY A RIBBON WEAVING MACHINE

Abstract

A weaving machine, particularly a ribbon weaving machine, with a shedding device, with a weft insertion device, with a reed for beating up a weft thread at a beating-up edge of the cloth web, and with a cloth take-up, the cloth web being guided by at least one freewheel device which enables the take-up travel and blocks a return of the cloth web in the opposite direction, characterized in that the freewheel device is assigned to the beating-up edge, wherein said freewheel device has a deflecting roller with a nonreturn device and wherein said deflecting roller provided with the nonreturn device has a slip-inhibiting surface.

Full Text

Weaving machine, particularly a ribbon weaving machine Technical field The invention relates to a weaving machine, particularly a ribbon weaving machine according to the preamble of claim 1. Prior art A weaving machine of the type initially mentioned is known, for example, from GB 316400, and in this a freewheel device is arranged at the cloth take-up. This makes it possible to prevent the cloth web from slipping back at the cloth take-up, but not what may be referred to as preweaving. The stable position of the warp and weft threads in the fabric is not established directly when the last weft thread is beaten up at the beating-up edge, but only a few wefts later. The weft thread last inserted moves away from the stable fabric zone since it was nearest to the stable zone during the beating-up of the weft. However, even the weft thread last inserted in the stable zone executes, as a result of the elasticity of the warp and fabric, a movement in one direction during the beating-up of the weft and a movement again in the other direction after the beating-up of the weft has taken place. The overall displacement of the beaten-up weft thread is visible as a fabric edge movement and is designated as precloth or preweave. The preweave is greater in the case of high-density fabrics than in the case of light fabrics, since high-density fabrics require a higher weft beating-up force. This preweave also depends, however, on the distance of the cloth take-up from the beating-up edge, since, if the distance is relatively great, the elasticity of the woven cloth web has a pronounced effect on the size of the preweave. It is therefore difficult to produce high-density fabrics. Presentation of the invention The object of the invention is to improve a weaving machine, particularly a ribbon weaving machine, to the effect that the preweave is reduced and a higher-density fabric can be produced. The object is achieved, according to the invention, by means of the characterizing features of claim 1. Since the freewheel device is assigned to the beating-up edge, it takes effect directly at the beating-up edge and, although enabling the take-up travel, by contrast blocks a return of the cloth web in the opposite direction, and, as a result, the preweave can be reduced and a higher-density fabric can be produced. Advantageous embodiments of such a weaving machine are specified in claims 2 to 6. The freewheel device may have a highly diverse form of construction. According to claim 2, the freewheel device has a deflecting roller with a nonreturn device. According to claim 3, this freewheel device may be assigned, preferably preceded by, a second deflecting roller, in order to improve the guidance of the cloth web around the first deflecting roller and to avoid the cloth web slipping through. Expediently, according to claim 4, the second deflecting roller is likewise provided with a nonreturn device. The design as claimed in claim 5 is particularly expedient, whereby the deflecting roller provided with the nonreturn device has a slip-inhibiting surface which at least makes it difficult for the cloth web to slip through. According to claim 6, the freewheel device is preferably assigned to a cloth holder or spreader which is arranged downstream of the beating-up edge. Although the freewheel device may be suitable for weaving machines for the production of broad cloth webs, it exercises its advantageous action particularly in ribbon weaving machines for the production of narrow cloth webs, such as ribbons, in which the preweave is particularly pronounced and it is therefore difficult to produce high-density cloth webs. Brief description of the drawings Exemplary embodiments of the invention are described in more detail below by means of a drawing in which the single figure shows diagrammatically the set-up of a weaving machine in a side view. Ways of implementing the invention The weaving machine shown diagrammatically in the figure, which is preferably a ribbon weaving machine, has a shedding device 2, in which warp threads 6 controlled via heddles 4 are opened into a shed 8. A weft insertion device, not illustrated in any more detail, inserts a weft thread 10 into the shed 8. The weft thread 10 is beaten up by means of a reed 12 at the beating-up edge 14 of a cloth web 16 to be produced. The cloth web 16 is taken up by a cloth take-up 18. The weaving machine has at least one freewheel device 20, by which the cloth web 16 is guided and which enables the take-up travel and blocks a return of the cloth web in the opposite direction. This freewheel device is mounted on both sides of the cloth web on frame parts 21 and is arranged as near as possible to the beating-up edge 14. In the present example, the weaving machine has a cloth holder 22 which is arranged near the beating-up edge 14 and which is followed by the freewheel device 20. The freewheel device 20 contains a first deflecting roller 24 which is provided with a nonreturn device 26. This first deflecting roller 24 is assigned a second deflecting roller 28 which is arranged between the cloth holder 22 and the first deflecting roller 24 and via which the cloth web 16 is guided in a meander-shaped manner, in order to improve the looping of the cloth web on the first deflecting roller 24 and to prevent slipping through. For this purpose, it is advantageous, further, if the surface 30 of the first deflecting roller 24 is of slip-inhibiting design. For this purpose, the surface may be roughened or be provided with a slip-inhibiting coating. It is advantageous if the second deflecting roller 28 is likewise equipped with a nonreturn device. Large numbers of nonreturn devices are known, such as, for example, ratchet mechanisms, freewheel or overrun clutches, clamping pawls or the like. The nonreturn device 26 is preferably designed as a grip-roller freewheel and preferably has gripping rollers 32 which cooperate in a known way with gripping ramps, not illustrated in any more detail, on the inside of the running sleeve 34 of the deflecting roller 24. List of reference symbols 2 Shedding device 4 Heddle 6 Warp thread 8 Shed 10 Weft thread 12 Reed 14 Beating-up edge 16 Cloth web 18 Cloth take-up 20 Freewheel device 21 Frame part 22 Cloth holder 24 First deflecting roller 26 Nonreturn device 28 Second deflecting roller 30 Surface 32 Gripping rollers 34 Running sleeve Patent claims 1. A weaving machine, particularly a ribbon weaving machine, with a shedding device (2) , with a weft insertion device, with a reed (12) for beating up a weft thread (10) at a beating-up edge (14) of the cloth web (16), and with a cloth take-up (18), the cloth web (16) being guided by at least one freewheel device (20) which enables the take-up travel and blocks a return of the cloth web (16) in the opposite direction, characterized in that the freewheel device (20) is assigned to the beating-up edge (14). 2. The weaving machine as claimed in claim 1, characterized in that the freewheel device (20) has a deflecting roller (24) with a nonreturn device (26). 3. The weaving machine as claimed in claim 2, characterized in that the deflecting roller (24) is assigned, preferably preceded by, a second deflecting roller (28). 4. The weaving machine as claimed in claim 3, characterized in that the second deflecting roller (28) is likewise provided with a nonreturn device. 5. The weaving machine as claimed in one of claims 2 to 4, characterized in that the deflecting roller (24, 28) provided with the nonreturn device (26) has a slip-inhibiting surface (30) . 6. The weaving machine as claimed in one of claims 1 to 5, characterized in that, downstream of the beating-up edge (14), it has, for the cloth web (16), a cloth holder (22) or spreader to which the freewheel device (20) is assigned. , f\ 1

Documents:

2351-chenp-2005 abstract-duplicate.pdf

2351-chenp-2005 claims-duplicate.pdf

2351-chenp-2005 description (complete)-duplicate.pdf

2351-chenp-2005 drawings-duplicate.pdf

2351-chenp-2005-abstract.pdf

2351-chenp-2005-claims.pdf

2351-chenp-2005-correspondnece-others.pdf

2351-chenp-2005-correspondnece-po.pdf

2351-chenp-2005-description(complete).pdf

2351-chenp-2005-drawings.pdf

2351-chenp-2005-form 1.pdf

2351-chenp-2005-form 18.pdf

2351-chenp-2005-form 3.pdf

2351-chenp-2005-form 5.pdf

2351-chenp-2005-pct.pdf