GB2123445A

GB2123445A - Circular looms

Info

Publication number: GB2123445A
Application number: GB08316368A
Authority: GB
Inventors: Franz Xaver Hueme
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-06-21
Filing date: 1983-06-16
Publication date: 1984-02-01
Also published as: CS452983A2; PT76906B; IT1194278B; FR2528881A1; AT375098B; CS245786B2; FR2528881B1; JPS599240A; ATA323382A; GB2123445B; CH657163A5; KR840005180A; BR8303275A; PT76906A; IT8321666A0; DE3321850C2; GB8316368D0; IN160082B; KR910002113B1; JPH0375652B2

Abstract

A shedding mechanism for a circular loom comprises a plurality of endless bands (20), arranged circularly round a main shaft, having a plurality of inner and outer yarn guiding eyes (26, 26%) for shedding the warp yarn (7), each yarn guiding eye being situated opposite a vertical slit (27 resp. 27%) in the band. The bands (20) are arranged around rollers (22), (23) and are reciprocated by a cam and roller mechanism (32), (31). The edges of the guide eyes and slits may be reinforced. <IMAGE>

Description

SPECIFICATION Circular loom The present invention relates to a circular loom by which a plurality of partial healds being arranged circularly round a main shaft of the loom, and each having a plurality of inner and outer yarn guiding eyes for the guidance of a part of the two systems of warp yarn distributed all round, which, for the formation of the weaving shed resp.

travelling shed, are given by way of the main shaft a countercurrent up-and-down alternating motion.

Hitherto known circular looms by which the inner and outer partial healds are arranged circularly in two rows round a main shaft of the loom, whereby a centrally revolving cam disc interacting driving mechanism engages directly on the partial healds to attain a countercurrent lifting motion between the inner and the outer partial healds. Each partial heald having thereby a number of rigid healds each with one yarn guiding eye, guiding in each case one warp thread.

Such driving mechanisms have always been very susceptible to wear and tear, and have been the cause of considerable disturbance on the weaving looms in question. Furthermore, such structures are very expensive in respect of maintenance and construction, and, furthermore, they cause considerable noise.

In order to attain a reduction of the moved elements of the change of shed device, a circular loom with only one row of fixed partial healds has already been proposed, each of which comprises a plurality of inner and outer yarn guiding eyes for the warp threads, which are fastened in pairs on the strands by endless strings. The endless strings of the respective groups on each partial heald are separately guided round two rollers that are spaced apart from each other and that constitute a double heald, whereby the warp threads guided through the inner resp. outer eyelets extend in each case between two opposite outer resp. inner stand of the strings.Further, all inner strands of the strings are fastened at their lower regions onto a vertical slide, which is moved up and down by way of the movement control means from the main shaft, whereby a countercurrent up-anddown alternating motion is conveyed onto the endless strings and hence onto the yarn guiding eyes, whereby the travelling shed is formed.

By means of these measures, it has been possible to substantially reduce the amount of moved control components on the change of web device, whereby a great number of new difficulties have come to stand. One disadvantage is the necessity to arrange the partial healds at a relatively wide angle and not tangential to the circular reed of the loom to permit a passing through of the warp yarns between neighbouring strings, which complicates the driving means for the change of web. Not eliminated is thereby that, at change of web, the warp threads are knocked against the neighbouring yarn guiding eyes that rise substantially above the respective strings, which is detrimental to the quality of the warp threads.Moreover, the production and maintenance of the partial healds with the required plurality of strings and the yarn guiding eyes arranged thereon, as well as the fastening of the strings on the vertical slide, is very complicated and expensive. Moreover, the drawing-in of the warp ends is very complicated and prone to fault.

It is therefore an object of the present invention to provide a circular loom of the previously mentioned type in such a manner that guarantees the advantages of the simplification of the driving means for the change of web, and, in addition to this, that the previously mentioned drawbacks of the prior art are avoided.

This is accomplished according to invention in that the inner resp. outer yarn guiding eyes of each partial heald permeate the respective strand of the endless guided band, extending over the width of the partial healds, over each of the rotatingly supported guide rollers on the upper resp. lower part of the frame of the partial healds, whereby each yarn guiding eye in the one said strand of the band is opposite to a vertical slit in the other said strand, and whereby, preferably on the inner strand of the band, the movement control means engage, preferably below said yarn guiding eyes and vertical slits, to create the countercurrent upand-down alternating motion of the strands of the band, forming thereby the travelling shed.

By means of these measures, it is now possible to produce an extremely reliable, simple and robust circular loom, which meets all the present requirements. In particular, the arrangement of the yarn guiding eyes and the associated vertical slits permits, according to invention, an easy and faultfree drawing-in of the warp threads, as well as their safe and protected straight pass through both strands of the partial heald band. The band itself is extremely wear resistant and practical, in comparison simple to produce as well as simple to assemble on the respective partial healds. Owing to the fact that the partial healds no longer need to be arranged tilted towards the circular reed, a very simple and unproblematic change of shed actuator is developed.In addition, it is possible to conduct substantially more warp threads per partial heald unit, than is possible with the conventional string arrangement, whereby considerably more-closely woven fabrics can be produced than was hitherto possible with such a circular loom.

From the foregoing, a further essential feature is attained in that the partial healds are arranged fixed on the loom in a tangential extension to the circular reed.

A very simple movement control means can be developed, moreover, for creating the alternating motion of the strands of the band, comprising a guided vertical slide, being situated preferably on the frame of the loom; the vertical slide being attached preferably to the inner strand of the band and that, over guide rollers, engages a cam of the plate cam, which is central revolving with the main shaft of the loom.

Furthermore, an advantageous development of the arrangement according to invention is that the band consists of high-quality polyamide or of steel or of a reinforced textile fabric of the like, whereby it is in addition to this advisable for the yarn guiding eyes in the band to consist of inserted eyelet elements of ceramics, sinter ceramics, steel or the like; and, in addition, for the vertical slits in the band to be defined by steel edgings vulcanized into the band.

By means of the latter measures, the resistance against wear and tear can be increased quite considerably under the greatest possible protection of the warp threads, which are guided and moved through the partial healds.

An example of a practical construction form according to the invention, described in more detail with reference to the accompanying drawings follows, wherein: Fig. 1 is a schematic representation in side view of a circular loom; Fig. 2 is a plan view of the circular loom shown in Fig. 1; and Fig. 3 is a diagrammatic representation of a partial heald of the circular loom shown in Figs. 1 and 2 on a larger scale.

The circular loom according to Figs. 1 and 2 is mounted in the conventional way on a loom base 1, and comprises a circular frame carrier 2, which carries a circular reed 3, a stop-start means 4 for the loom, and further frame members 5 for supporting the partial healds 6. These partial healds 6 are arranged here circularly round the main shaft 8 of the loom, as the following description describes in more detail.

In addition, the support 9 for the textile drawing-off device is supported on the loom base.

Amongst other things, this support comprises the drive 10 for the cloth removal as well as the cloth drawing-off rollers 11 and 12 and the bale of cloth. A cloth expander 14 is also disposed in the drawing-off area. Further, in the circular loom illustrated, it is also possible to see the feed roller 1 5 for the warp threads on the left-hand side and the feed roller 16 for the warp threads on the right-hand side. These warp threads 7 are divided into two warp thread gatherings, and are drawn off by groups of warp thread spools, which are not illustrated more closely here. For the formation of the weaving shed, one of these thread gatherings is lifted up while the other is guided down from the level of the weaving plane through the socalled change of shed motion, so that a warp thread upper shed and a warp thread lower shed result. In this so-called weaving-resp.travelling shed, a shuttle 30 with a bobbin of weft yarn is passed through on a horizontal circular path.

Owing to the circular motion of the shuttle, the pick wound off from the bobbin of weft yarn is transferred onto the edge of the tubular fabric so that this bobbin thread can be woven into the fabric. The tubular fabric can then be drawn off and laid together as a flat tubular fabric.

To the extent described above, the construction of the circular loom corresponds to the known technical stand so that further explanation of such a loom is unnecessary.

The problem that is to be taken into consideration here on such a circular loom as previously described, has its existence in the arrangement of the means for the formation of the change of shed motion on both of the warp thread gatherings.

As can be inferred from Fig. 1 and in particular Fig. 2, each partial heald 6 comprises an endless band 20 extending over the width of the partial healds and over each of the rotatingly supported guide rollers 22 resp. 23 on the upper resp. lower part of the frame 21 of the partial healds.

The inner strand 24 and the outer strand 25 of the band 20 are each permeated by a horizontally extending row of yarn guiding eyes 26 resp. 26', whereby those in one strand face the interstices of those in the other strand. Hereby the arrangement is further designed so that each yarn guiding eyes 26 resp. 26' in the one strand 24 resp. 25 is situated opposite to a vertical slit 27' resp. 27 in the other strand 25 resp. 24.

As can be seen from the illustration of Fig. 3, one warp yarn 7 of one or the other warp yarn systems is pulled alternately through a yarn guiding eye-26 in the inner strand 24 and the accompanying vertical slit 27' in the outer strand 25 resp. a yarn guiding eye 26' in the outer strand 25 and the accompanying vertical slit 27 in the inner strand 24 respectively. The generation of a countercurrent up-and-down alternating motion of the strands 24 and 25 of the band 20 permits the accomplishment of the previously mentioned change of shed motion on both of the warp yarn sheets.

It can already be seen here that for the production of the previously mentioned countercurrent up-and-down alternating motion of the strands 24 and 25 of the band 20, only the simplest movement control means and actuating means are required.

A suitable arrangement for this can comprise, by way of example, a vertical slide, preferably travelling on the loom frame 28, which is preferably connected with the inner strand 24 below its yarn guiding eyes 26 and vertical slits 27. From this vertical slide 29, guide rollers 31 project down, which are supported by a rotating plate cam 33 on a corresponding curved guide profile 32, being central revolving with the main shaft 8 of the circular loom.

It is evident that this arrangement is very robust, simple and resistant to wear. This is attained in particular in that it is here possible to arrange the partial healds 6 in an exact tangential extension to the circular reed 3, permitting a straight and lateral tension-free passing of the warp yarn 7 through the eyelets 26 resp. 26' and the vertical slits 27 resp. 27' of the strands sides 24 and 25 of the partial heald band 20.

The band 20 itself, the holes and slits of which can be punched out in the simplest manner, can consist of various materials, for example highquality polyamide or steel or reinforced textile fabric and the like.

In addition, the yarn guiding eyes 26 resp. 26' in the band 20 can consist of inserted eyelet elements of ceramics, sinter ceramics, steel or the like. Equally, the vertical slits 27 resp. 27' in the band 20 can be formed of wear-resistant and thread protecting steel edgings that are vulcanized into the belt. Should the warp be composed of narrow tapes of relatively large cross section, which would require correspondingly large yarn guiding eyes resp. thread eyelets and vertical slits, can the respective ribs 35 (Fig. 3) between neighbouring thread eyelets and vertical slits be very small. To prevent a tearing into the band here, it is of advantage to strengthen the band in this area, for instance by fastening flaps, which can protrude from the here longish eyelet elements to be inserted for the warp tapes.

From the foregoing description, there results a circular loom, the conception of which permits, according to invention, a simple, robust, precise and unproblematic change of shed.

Claims

1. A circular loom having a plurality of partial healds, being arranged circularly round a main shaft of the loom, and each having a plurality of inner and outer yarn guiding eyes for the guidance of a part of the two systems of warp yarn distributed all round, which, for the formation of the wearing shed resp. travelling shed, are given by way of the main shaft a countercurrent up-anddown alternating motion; characterized in that said inner resp. outer yarn guiding eyes (26 resp.

26') of each said partial heald (6) permeate the respective strand (24 resp. 25) of the endless guided band (20) extending over the width of said partial healds and over each of the rotatingly supported guide rollers (22, 23) on the upper resp.

lower part of the frame of said partial healds, whereby each yarn guiding eye in the one said strand of the band is situated opposite to a vertical slit (27' resp. 27) in the other strand, and whereby, preferably on said inner strand (24) of said band (20), said movement control means (31, 32, 33) engage, preferably below said yarn guiding eyes (26) and vertical slits (27), to create said countercurrent up-and-down alternating motion of said strands (24 and 25) of said band (20), forming thereby said travelling shed.

2. A circular loom as in Claim 1, characterized in that said partial healds (6) are arranged attached to the loom in a tangential extension of the circular reed (3).

3. A circular loom as in Claim 1, characterized in that said movement control means (31, 32, 33), for creating the alternating motion of said strands (24, 25) of said band (20), comprising a guided vertical slide (29), being situated preferably on said frame of the loom; said vertical slide being attached preferably to said inner strand (24) and that, over said guide rollers (31), engages a cam (32) of a plate cam (33), which is central revolving with said main shaft (8) of the loom.

4. A circular loom as in Claim 1, characterized in that said band (20) consists of high-quality polyamide or of steel or of a reinforced textile fabric or the like.

5. A circular loom as in one or severai of the preceding Claims 1 to 4, characterized in that said yarn guiding eyes (26 resp. 26') in said band (20) consist of inserted eyelet elements of ceramics, sinter ceramics, steel or the like.

6. A circular loom as in one or several of the preceding Claims 1 to 5, characterized in that said vertical slits (27 resp. 27') in said band (20) are defined by steel edgings vulcanized into said band.

7. A circular loom as in Claims 5 and 6, characterized in that said band (20) is reinforced in the area of the ribs (35) of said neighbouring yarn guiding eyes (26 resp. 26') and said vertical slits (27 resp. 27').