US20050262673A1 - Device for removing needles from a fabric web - Google Patents

Abstract

At the outlet end (B) of a tentering frame (1), on the side of the tentering frame chains with needle plates (3) there are transport means (11) in the shape of conveyor belts (19) and clamping bands (23), whose runs (19′, 23′) intersect the plane (E) formed by the tentering frame chains (3) at an acute angle (alpha) at a point (X). The needles are removed from the fabric web (39) which is guided in a clamped way during the needle removal by the conveyor belts (19) and clamping bands (23).

Description

BACKGROUND
• The object of the invention is a device for removing needles from a fabric web carried on a tentering frame, with two tentering frame chains, which carry the fabric web by its longitudinal edges and which transport and hold the fabric web in tension perpendicular to a transport direction between a web receiving point and a web outlet point.
• For processing textile webs, especially knitted, double-ribbed, as well as stitched textiles, and also for nonwoven fabrics, the fabric web is fixed along its longitudinal edges by needles on a tentering frame. At the end of the tentering frame, the fabric web must be removed as carefully as possible from the needle setting, which is typically embodied on circular transport bands. The removal can be achieved by wedge-shaped rails, which lie at an acute angle to the fabric web, which extend parallel to the needled bands, and which successively lift the fabric web from the needle setting. In a tentering frame at the end of the run of the material web, because the latter is usually held in tension between the needles, removing the needles can damage the edges of the material web, as soon as the web is no longer completely held by the penetrating needles.
SUMMARY
• An object of the present invention is to create a device for removing needles from a fabric web, in which the fabric web is not damaged by the needles when the needles are removed.
• This objective is achieved by a device according to the features of the invention, in which at the web outlet point at the side of the tentering frame chains there is at least one conveyor belt having a first segment intersects the transport plane of the tentering frame chains at an angle.
• With the device according to the invention, the fabric web is held in a controlled way during the needle removal and, as much as desired, also afterwards. The tensile forces acting from the fabric web perpendicular to the transport direction can be temporarily assumed by the device during the needle removal. The device further enables a controlled transition to the subsequent transport means, whether it is a transport belt running at the same speed or a transport belt at a lower speed in order to flatten the fabric web and to give the web the opportunity to shrink (relax).
BRIEF DESCRIPTION OF THE DRAWINGS
• The invention will be explained in more detail with reference to an illustrated embodiment. Shown are:
• FIG. 1 is a view of a tentering frame with diverging needled bands,
• FIG. 2 is a longitudinal section view along line II-II inFIG. 1 through the device, and
• FIG. 3 is an enlarged cut-out of the longitudinal section inFIG. 2 in the transfer/transition region.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• InFIG. 1, illustrated by a trapezoid, atentering frame1 with two tentering frame chains withneedle plates3 designed for the web transport can be seen. The tentering frame chains withneedle plates3 run endlessly aroundguide rollers5,7 and are driven by a motor M. Between theguide rollers5,7, the upper ends of the tenteringframe chains3 are supported onsliding surfaces9. The two tenteringframe chains3 diverge in the illustrated example. Consequently, on the inlet side at the web receiving point A, the two tenteringframe chains3 lie closer to each other than at the web outlet point B. The formation of thetentering frame1, as shown schematically in the drawings, is not described in more detail, as it is known from the state of the art.
• In the region of the web outlet point B, corresponding transport means11 are arranged between the twotentering frame chains3 directly adjacent to each chain. The two transport means11 can be arranged parallel to the adjacenttentering frame chains3 or they can enclose an acute angle beta with these chains. The transport means are preferably endless conveyor belts orpulleys19 rotating around at least twoguide rollers13,15. Adeflection roller17, which divides the upper run of theconveyor belt19 rotating on theguide rollers13,15 into twosegments19′ and19″, is preferably inserted between the twoguide rollers13,15. Thelower run19′″ can likewise be deflected upwards by asupport roller21 as much as necessary for structural reasons. Theconveyor belts19 can be driven by a motor (not shown), preferably a servo motor. Anendless clamping band23 runs over eachconveyor belt19 over at least twoguide rollers25,27. Theirlower runs23′ contact both thesegment19′ and also thesegment19″ and in this way they are deflected. Theupper run23′ can be lifted by adeflection roller29, if necessary.
• Alternatively, at the point where conveyor belts are deflected by deflection rollers, conveyor belts, which are offset relative to each other and which have a segment that assumes the desired angle, can be used.
• At the position x, theupper run19′ of thetransport belt19 intersects the plane E, in which the upper segments of thetentering frame chains3 run at an acute angle alpha in the illustrated example. The intersecting angle between the plane E and theupper run19′ can equal up to 90°.
• The transport means11, including thetransport belt19 and theclamping belt23, extend past the web transfer region A and also extend past aconveyor system33 cooperating with the tenteringframe1. This system can be a band, lattice, orscreen37, which extends around theguide rollers35 and on which afabric web39 passing through the tenteringframe1 is carried away.
• In the following, the method of operation of the device is explained in more detail. In the figures, thefabric web39 is guided from the left in a known way to thetentering frame1 and connected to thetentering frame chains3 along its edges. Thematerial web39 in the example of adivergent tentering frame1 is successively pulled apart perpendicular to the transport direction T by the twotentering frame chains3, which are driven in sync. Shortly before reaching the web outlet point B, the edge regions of thefabric web39 are brought into contact with thetransport bands19 of the transport means11. Due to thesegment19′ of thetransport bands19 running upwards at the acute angle alpha, the edges of thefabric web39 are successively lifted and led out of the needles of thetentering frame chains3 and thus the connection to theneedle bands3 is broken. During the run-out of the web edges, thefabric web39 is pressed by thelower run23′ of theclamping band23 to thesegment19′ of thetransport band19 and thus held or clamped tight. The clamping of thefabric web39 during the needle removal cancels the tensile forces, which have been generated by the expansion of thefabric web39 in thetentering frame1 and prevents the needles from pulling threads out of the surface of the lower side of thefabric web39.
• The guidance of theconveyor belts19 andclamping bands23 at an acute angle beta to the transport direction of thetentering frame chains3 has proven to be especially advantageous. Through these measures, thefabric web39 is stretched further perpendicular to the transport direction T by the mentioned bands during the needle removal and thus the tensile forces on the needles at the tenteringframe chains3 are completely canceled.
• The controlled needle removal of theweb39 from the tenteringframe1 enables the releasedweb39 to be deposited on asubsequent conveyor system33, whose conveyor speed v₂, e.g., can be less than the conveyor speed v₁of the tenteringframe chains3 in order to give thematerial web39 the opportunity to shrink/relax. The conveyor speed of theconveyor band19 and theclamping band23 can likewise be different with reference to the speed v₁of the tenteringframe chains3 in order to aid the needle removal.

Claims (5)

1. Device for removing needles from a fabric web (39) in a tentering frame (1), comprising two tentering frame chains (3), which carry the fabric web (39) on longitudinal edges thereof and which transport and hold the fabric web (39) in tension perpendicular to a transport direction (T) between a web receiving point (A) and a web outlet point (B), at the web outlet point (B) at a side of the tentering frame chains (3) there is at least one conveyor belt (19) having a first segment (19′) that intersects the transport plane (E) of the tentering frame chains (3) at an angle (alpha).

2. Device according toclaim 1, wherein a second segment (19″) of the at least one conveyor belt (19) lies at an acute angle to the first segment (19′) and extends past the web outlet point (B).

3. Device according toclaim 1, wherein over the at least one conveyor belt (19) there is a clamping band (23) having a lower run (23′) that lies opposite the first segment (19′) of the conveyor belt (19), which forms an upper run.

4. Device according toclaim 1, wherein there are at least two of the conveyor belts (19) that are arranged at an acute angle (beta) to the tentering frame chains (3).

5. Device according toclaim 1, wherein the tentering frame chains (3) and the at least one conveyor belt (19) can be driven independently and at the same and different speeds.

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