GB2092193A

GB2092193A - Shearing a pile fabric

Info

Publication number: GB2092193A
Application number: GB8136788A
Authority: GB
Original assignee: Mueller Franz & Co GmbH
Current assignee: Mueller Franz & Co GmbH
Priority date: 1981-01-30
Filing date: 1981-12-07
Publication date: 1982-08-11
Also published as: FR2499111A1; ES507693A0; IT8219134A0; IT1149464B; GB2092193B; DE3103079A1; CH653392A5; JPS57183466A; DE3103079C2; ES8300152A1

Abstract

A plurality of rotary circular shearing wheels 3 are disposed adjacent to each other transversely with respect to the fabric web feed direction opposite to a cutting table or cylinder 1 with the shortest possible distance between the cutting edges which will just prevent mutual contact between the wheels. As a result, the cutting zone in the feed direction is shortened to a minimum, without increasing the machine width. An extraction system 5 removes cut off pile fibres and erects the fibres to be cut. A device 8 for grinding the wheels 3 in situ is provided. <IMAGE>

Description

SPECIFICATION Apparatus for cutting a textile fabric web provided with a nap The invention relates to apparatus for shearing a textile fabric web with a pile.

German Patent Specification AS 23 14557 discloses a pile shearing apparatus with'a cutting table for supporting the fabric web in the shearing zone and in which a cutting blade, situated opposite the cutting table and operating without a mating blade, is constructed as a circular shearing wheel adapted to rotate about an axis extending substantially perpendicularly to the fabric web and with a cutting edge on the circumference.

The shearing wheel has a diameter larger than the width of the fabric web as measured transversely to the feed direction. The circumference of the shearing wheel can be constructed as a single, smooth cutting ring.

Whereas the fibres shown off by conventional shearing machines with shearing cylinders and bottom knives would be practically pulverized owing to the number of shearing spirals and because of the rotational speeds, it should be possible with the system of AS 2314557 to cut off the fibres without sub-dividing them and to re-use them, for example as filler material or as an addition in the production of slivers.

The system disclosed in German AS 23 14 557 has however not proved itself, because shearing is performed over a circular arc the depth of which in the fabric feed direction can increase almost to half the shearing wheel diameter. In the cutting region defined by this circular arc, the fabric web to be sheared must be held, for example tensioned between two cylinders, precisely parallel with the plane defined by the circular arc. However, this cannot be achieved in practice, inter alia because the shearing wheel of large surface area produces a substantial air flow which urges the fabric web to be sheared out of the required position in the shearing zone. The cutting zone depth defined by the shearing part of the circular arc and measured in the feed direction can be reduced only by increasing the diameter of the shearing wheel.

This however results in corresponding lateral overhang of a substantial portion of the shearing wheel beyond the working width of the machine.

It is the object of the present invention to shorten the cutting zone in the feed direction to a minimum without increasing the width of the machine. According to the invention, a plurality of shearing wheels are arranged side by side on a line extending transversely to the fabric web feed direction, opposite to the cutting table, the distance between adjacent shearing wheels being the smallest possible which will just preclude mutual contact between them.

In apparatus according to the invention it is possible, completely unexpectedly, to obtain smooth, line-free shearing by means of individual shearing wheels which are arranged at a (slight) distance from each other. Such a result could not be expected, because it was not possible to predict the reaction to shearing of the pile fibres disposed in the region between or at the boundary between two shearing wheels. It was also not possible to allow the cutting edges to overlap to a small extent because this would have resulted in the appearance of lines in the shearing pattern.

Finally, the cutting edges of adjacent shearing wheels must not be in contact with each other for reasons which are readily understood.

Further details of the invention are explained by reference to the accompanying drawings which are a diagrammatic illustration of one exemplary embodiment of the invention and in which: Fig. 1 is a cutting apparatus shown in section parallel with the fabric web feed direction, and Fig. 2 is a plan view of the shearing wheels of the apparatus and of the fabric web seen perpendicularly to the plane of the fabric web.

As shown in Fig. 1, the textile fabric web 2 is guided over a cutting table, in this case formed by a cylinder 1, associated with a plurality of rotating circular blades or cutting wheels3 arranged in a line perpendicular to the web feed direction F. The blades lie in a plane parallel to the web and facing the cutting table or cylinder 1. The cutting length of the pile fibres 9 in the fabric web 2 can be preset by adjusting the distance between the shearing wheels 3 and the cutting table or cylinder 1. As indicated in Fig. 2, the shearing wheels 3 can all counter-rotate in the directions indicated by the arrows. This ensures perfect cutting even of the fibres and filaments situated along the line defined by the very small gap between two adjacent shearing wheels 3.The shearing wheels or cutting blades can be arranged horizontally as illustrated or vertically (and in all other angular positions). According to the exemplified embodiment, the rotating cutting wheels 3 are supported by a cutting beam 4 which is also associated with a suction extraction system 5 and carries a bearing 6 and a drive 7 for each cutting wheel 3. By means of the extraction system 5, which at least partially surrounds the cutting zone, the cut-off fibre ends can be extracted and fed to a corresponding container. By means of the airstream in the extraction system 5 as indicated by the arrow, the fibres 9 can also be erected in the cutting region (and drawn against the cutting edges).

Since cutting is performed without a mating blade, it follows that the cutting edges of the shearing wheels must be particularly sharp. It is therefore advantageous to associate a grinding device 8 with the cutting wheels 3, which grinding device is movable towards the cutting edges in the direction of the arrow. In this way it is possible for the circular blades to be ground in situ.

Cutting the fibres with circular wheels or circular knives according to the invention is performed over a relatively short cutting zone the maximum length of which in the feed direction.

indicated by an arrow F, is equal to half the diameter D of the individual circular wheels 3.

If the diameter D is of the order of magnitude of 100 mm, it follows that the cutting zone has a length of approximately 50 mm in the feed direction. It is therefore perfectly feasible to use a cutting table constructed as a roller table, edge table or hollow table. The roller 1 in the exemplified embodiment illustrates a roller table.

The distance d between adjacent blades is as small as possible, but the blades do not touch.

Advantageously, the distance d between the shearing wheels should correspond to the order of magnitude of the thickness of the individual threads or fibres of the pile which is to be cut, and should be more particularly approximately 0.01 mm. Furthermore, it can be advantageous to select the diameter D of the shearing wheels to be more particularly of the order of magnitude of 100 mm, which is small in relation to the width of the fabric web which is to be sheared.

Claims

1. Apparatus for shearing a textile fabric web with a pile, comprising a cutting table for supporting the fabric web in the shearing zone, and a plurality of cutting blades, facing the cutting table and each operating without a mating blade, each blade being a circular shearing wheel adapted to rotate about an axis substantially perpendicular to the fabric web and with a smooth cutting edge on the circumference of the wheel, the cutting wheels being adjacent to each other in a line extending transversely to the running direction of the fabric web adjacent to the cutting table with the shortest possible distance between the cutting edges which will just prevent mutual contact between said wheels.

2. Apparatus according to claim 1, in which the distance between the cutting edges'is of the order of magnitude of the thickness of the individual filaments of the pile which is to be cut.

3. Apparatus as claimed in claim 1 or 2 in which the distance between the cutting edges is approximately 0.01 mm.

4. Apparatus according to claim 1,2, or 3 in which the diameter of the cutting wheels is small with respect to the width of the fabric web which is to be sheared.

5. Apparatus as claimed in claim 4 in which the cutting wheel diameter is of the order of 100 mm.

6. Apparatus according to any of claims 1 to 5 including extraction means for drawing off the fibre particles cut off from the pile and serving simultaneously for erecting the fibres of the pile which are to be cut.

7. Apparatus for shearing the pile of a textile web, substantially as herein described with reference to the accompanying drawings.