GB2187766A

GB2187766A - Marking woven fabrics

Info

Publication number: GB2187766A
Application number: GB08703550A
Authority: GB
Inventors: Franz Xaver Starlinger-Huemer
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-02-28
Filing date: 1987-02-16
Publication date: 1987-09-16
Also published as: DE3704664A1; GB8703550D0; AT388401B; CH669801A5; ATA42287A; IT8719466A0; IN167263B; GB2187766B; JPS62206050A; KR870008066A; IT1203345B; BR8700977A

Abstract

A punching or perforating device (50) for producing register marks (15) in the form of perforations in the transverse bands formed by the weft thread thickenings (9) is arranged on the circular loom. Such perforations (15) permit a subsequent reliable scanning for producing the cut lengths on a cutting machine, which are specified by the weft thread thickenings. <IMAGE>

Description

SPECIFICATION Method and device for the manufacture of a tubular fabric, for the manufacture of sacks, on a circular loom The present invention relates to a method for the manufacture of a tubular fabric, for the manufacture of sacks, on a circular loom, in which, in the tubular fabric, weft yarn thickenings ensue periodically and with predetermined spacings forming transverse bands, at which places a subsequent cutting of the fabric web takes place, for which a readable or scannable register marking is applied to the fabric, the individual marks thereof corresponding to the longitudinal spacings of the transverse bands in order to render a subsequent registrationstable advance of the fabric web, which is to be cut, possible.

Methods of the kind specified for manufacturing, for example, sacks, have the basic disadvantage that it is difficult to always cut the web precisely at The weft thread thickenings so as to obtain suitable proportions of the bands for both the sack end and the sack bottom. Hitherto, therefore, a cutting machine had to be used and a particular cutting place selected and monitored by the operative in a way which cannot meet present-day demands for rational manufacture.

Accordingly, attempts have already been made to apply reference marks, in form of black spots or the like and disposed at predetermined spacings, to the endless fabric web, so as to scan them by means of beams of light and to actuate the cutting machine with the obtained output signal.

Here, however, this has proved to be in no way sufficient since such markings are in many cases covered over by deposits of fibers resp. fluff to such an extent that the scanner disposed on the cutting machine can no longer recognize them.

It is thus the object of the present invention to apply a register mark, the individual marks of which permitting of detection clearly and without error by means of a suitable scanner.

This is achieved according to the invention thereby, that, at a location of the circular loom, between the zone where the tubular fabric is laid flat and the textile beam, the register marking, in form of at least one perforation, is in each case applied to the transverse bands formed by the weft thread thickenings.

These steps therefore enable the perforations for a subsequent registration-stable advance of the fabric which is to be cut to be scanned absolutely reliably as a complete covering-over of the register marks through fluff or the like is impossible. If scanning takes place by air, even a thick covering of fluff cannot be impeding since the jet of air would blow away the fluff, which would here also result in a perfect signal.

Further, the present invention relates to a circular loom for executing the method according to the invention, which is provided with a device to so control the sequence of warp thread insertion as to effect periodic production of weft thread thickenings formed at predetermined spacings.

The special features of the circular loom according to the invention are that at least one punching or perforating device for producing the register marks in the form of perforations in the transverse bands, formed in each case by the weft thread thickenings, is disposed on the circular loom in the zone of the fabric web and which is operable synchronously with the control device for the sequence of warp thread insertion and which is disposed in the zone between the place where the tubular fabric web is laid flat and the textile beam.

An embodiment of a circular loom for carrying out the method according to the invention will now be more particularly described by way of example with reference to the accompanying drawing, the single figure of which is a schematic view of a device for manufacturing the register marks according to the invention on a circular loom.

In Fig. 1, there is shown part of a circular loom indicated by a woven fabric 1 with a shed formed by the upper warp yarns 2 and the lower warp yarns 3. A weft yarn is inserted into the shed by means of a shuttle 20 which is guided along a horizontal circular path. The weft yarn is inserted in known manner in the zone of upper and lower guide rings 21 and 22 of the loom, into the proximation zone of which a weft yarn positioning ring 23 on the shuttle 20 extends. The shed of the upper and lower warp yarns 2 and 3 is opened in known manner by healds 24.

The tubular fabric web 1 thus woven from the warp and weft yarns is drawn off upwards and laid flat in the zone of drawing-off rollers 25 (only one of which is shown) and is then conveyed onwards, in the direction indicated by arrow 26, in the flattened form and wound onto a textile beam 40 in known manner.

For the production of transverse bands 9, which are formed from weft yarn thickenings and which follow one another periodically at a given distance, in order to form reinforced edges in subsequent finished products, the loom is provided with an appropriate control device 10 for controlling the sequence of weft yarn introduction. In the illustrated embodiment the control device is merely indicated by a camshaft.

Subsequently, the endless tubular fabric web 1 is then conveyed to a cutting machine (not shown) which severs the individual sacks accordingly by means of a cut along the weft thread thickenings 9. In order then to enable the web to be cut precisely in relation to the transverse band-shaped weft thread thickenings 9, steps are taken to provide the fabric web 1 with register markings 15.These register markings 15 are perforations in the bands of the transverse weft thread thickenings 9 in order to render a subsequent registration-stable advance of the fabric web 1, which is to be cut, possible Such perforations 15 according to the invention give register markings which are easily and absolutely disturbance-freely scannable resp. readable by light or air barriers, which are far superior to the hitherto-known electromagnetic strip markings and printed coloured marks, since the latter may easily become covered over with fibers or fluff and are then no longer readable, which can lead to great disturbances upon a subsequent advancing to the cutting machine by means of the scanning ring of the register markings. This is now impossible.

For this, at least one suitable punching or perforating device 50 with an orifice plate 51, with a wiper 52 situated near the edge, and a punch 53, which is operable by an electro magnet 54 or also hydraulically or pneumati cally operable, is disposed on the circular loom between the drawing-off roller 25, thus in the zone where the tubular fabric web 1 is laid flat, and the textile beam 40.

It is to be mentioned here that such a device 50 can be arranged on the one or the other fold edge of the web, or on both of them or anywhere between them. Similarly, rows of perforations can be provided as register marks.

The marking device 50 is actuated accord tingly by the control device 10 for the sequence of weft thread insertion, which, in the illustrated embodiment, is indicated by the chain-dotted line 16, and which places the register marks 15 along one fold edge of the web or along both of its fold edges.

Claims

1. A method for the manufacture of a tu bular fabric, for the manufacture of sacks, on a circular loom, in which, in the tubular fabric, weft yarn thickenings ensue periodically and with pedetermined spacings forming transverse bands, at which places a subse quent cutting of the fabric web takes place, for which a readable or scannable register marking is applied to the fabric, the individual -marks-thereof corresponding to the longitudi nal spacings of the transverse bands in order to render a subsequent registration-stable advance of the fabric web, which is to be cut, possible, characterized thereby, that, at a location of the circular loom, between the zone where the tubular fabric web is laid flat and the textile beam, the register marking, in form of at least one perforation, is in each case applied to the transverse bands formed by the weft thread thickenings.

2. A circular loom for executing the method as claimed in claim 1, provided with a device to so control the sequence of warp thread insertion asto effect periodic pro duction of weft thread thickenings formed at predetermined spacings, characterized thereby, that at least one punching or perforating de vice for producing the register marks in the form of perforations in the transverse bands, formed in each case by the weft thread thick enings, is disposed on the circular loom in the zone of the fabric web and which is operable synchronously with the control device for the sequence of warp thread insertion and whidh is disposed in the zone between the drawing off roller, thus in the zone where the tubular fabric web is laid flat, and the textile beam.

3. A circular loom substantially as -herein- before described with reference to the accom panying drawing.

4. Any novel integer or step, or combina tion of integers or steps, hereinbefore de scribed and/or shown in the accompanying drawings irrespective of whether the present claim is within the scope of, or relates to the same or a different invention from that of, the preceding claims.

5. A method for the manufacture of a tu bular fabric, for the manufacture of sacks, on a circular loom substantially as hereinbefore described with reference to the accompanying drawings.