GB2161504A

GB2161504A - Jet looms

Info

Publication number: GB2161504A
Application number: GB08514595A
Authority: GB
Inventors: Zdenek Horak; Jiri Vystrcil
Original assignee: VYZK VYVOJOVY USTAV
Current assignee: VYZK VYVOJOVY USTAV
Priority date: 1984-06-15
Filing date: 1985-06-10
Publication date: 1986-01-15
Also published as: IT8521150A0; CH668784A5; IT1185036B; FR2566008A1; GB8514595D0; DE3521244A1

Abstract

A jet loom has specially shaped reed dents 7 which form the weft guiding channel (Figs. 2 to 11 and 15 to 22), some dents not being so shaped (Figs. 12 to 14) to provide gaps for the auxiliary nozzles 12. <IMAGE>

Description

SPECIFICATION Device for forming fabrics in pneumatic weaving machines The present'invention relates to a device for forming fabrics in pneumatic weaving machines, in which the weft is guided upon insertion through a channel formed of the beat-up reed dents.

The devices for forming fabrics known hitherto use several types of guiding channels and, together therewith, also beat-up reeds. A device is known, in which the guiding channel is formed of guiding plates with orifices mounted in the slay carrier beam of the beatup mechanism. Behind this guiding channel, formed of guiding plates is fastened, in the direction from the beat-up in the slay carrier beam, a beat-up reed consisting of rectilinear dents fixed in the reed frame. Between each dent, one or several threads are drawn in, which are thus continuously distributed by the dents. The guiding plates of the guiding channel are thicker than the reed dents, and thus their number in the carrier beam of the slay is less than the number of dents.During weaving, upon opening the shed, when the reed moves back from the beat-up, the warp threads are distributed evenly thereby and the guiding plates of the guiding channel enter the shed from below. Because the guiding plates of the guiding channel are thicker, and their number along the length of the reed is less, the number of warp threads in the gap therebetween cannot be equal to that in the reed, and thus re-distribution and re-bundling has to take place. The warp threads are redistributed by the guiding plates and, into one gap therebetween, a higher number thereof is to be placed than between the reed dents.

This is disadvantageous, as just in that place, warp thread breakages or their damaging occur, due to their pinning up by the guiding plates of the guiding channel. This disadvantage is encountered particularly with twistless or low twisted yarns and, furthermore, with monofilament yarns, from which separate particles of the fibre are drawn out by the guiding channel. Upon movement of the reed into the beat-up position, the weft yarn is removed from the guiding channel through a riding over slot, and the guiding channel again leaves the warp threads. The weft yarn is caught up by the rectilinear reed dents and is beaten up into the binding point. A further disadvantage of that arrangement consists in the gap between the guiding channel and the beat-up reed, because the applicable inserting angle of the guiding channel is diminished for that size.

A further disadvantage of the channel formed in that manner consists in the necessity of providing a sufficiently large opening thereof, as the effort of reducing the diameter of said opening has an unfavourable effect of the riding over slot on the weft insertion. The pressure fluid escapes during weft insertion directly through the riding over slot, thus causing a disturbed advancement of the weft and short picks are caused thereby. This disadvantage is eliminated by various resilient latches provided in the guiding plates. These latches, intended for closing the riding over slots or gaps of the guiding plates are, however, difficult to manufacture and, moreover, each inserted weft yarn must overcome their spring resistance, upon riding over. Thus, the weft is rubbed and fibrillated.For that reason, guiding channel plates adapted in such manner can be used only with certain types of yarns. Another possibility of eliminating the sucking effect of the riding over slot consists in enlarging the actual opening of the guiding channel. In that manner, the percentage proportion of the riding over slot is reduced. The disadvantage of that emodiment consists in the necessity of a higher pressure fluid input, and further the impossibility of using the shed for insertion at its small angular opening, which makes it impossible to increase the speed of the machine, and thus also its output.

A further known embodiment of the device for forming fabrics has an open guiding channel formed of profiled dents of the beat-up reed. The guiding channel has the shape of an inclined open letter U, in which the missing outer wall of the channel is substituted during weft insertion by auxiliary nozzles distributed along its whole length. The warp threads are distributed between the profiled dents. Thus, during weaving, the separate warp threads are continuously evenly distributed. The weft is introduced by the main nozzle into the guiding channel, in which its advancement is performed by auxiliary nozzles. The pressure fluid flow delivered therefrom simultaneously closes the opened side of the guiding channel. Upon performing beatup, the weft does not leave the opened channel, but its beat-up is performed by the rear wall of the guiding channel.As the guiding channel is not closed, its missing wall is substituted by the pressure fluid flow, which must be reinforced. This is disadvantageous because of increased consumption of the pressure fluid, the weaving machine becoming thus more complicated from the viewpoint of its power consumption and its operation.

In a further embodiment of the device for forming fabrics hitherto known, the guiding channel is also made of profiled dents. The guiding channel has substantially a rotary shape with a semicircular front side, while its opposite side is vertical and their connecting line rectilinear and inclined downwards towards the arcuate part. The riding over slot is rectilinear, in the same manner as in the guiding plate channel embodiment. Thus, the same disadvantages are encountered there as those specified for the riding over slot of the guiding plate channel. The bodies of the auxiliary nozzles are inserted into the gap in the guiding channel from the front part. The gap in the channel is formed by that on a certain number of dents beside each other, the guiding channel is not closed by the arcuate part.

The symmetry of the channel, moreover, reduces the weft insertion angle, which shortens the time interval, during which the weft can be inserted into the shed. The dents of the beat-up reed are thus, except the point of the guiding channel, rectilinear. Therefore, the bodies of the auxiliary nozzles can be introduced into the channel only from the front side, as otherwise, within a very short section, a new distribution of the warp threads by the bodies of the auxiliary nozzles would take place.

The above mentioned disadvantages are mitigated by a device for forming fabrics in pneumatic weaving machines, according to the invention in which the dent is shaped out from the beat-up side in a direction away from the binding point.

In an embodiment of the invention by the outward shaping at least one part of a labyrinth-shaped riding over slot is formed.

The bodies of the auxiliary nozzles may be introduced into the lower part of the guiding channel from below in a direction towards the riding over slot.

The advantage of the device according to the present invention consists in that by shaping out a part of the dent, space for the bodies of the auxiliary nozzles, their mounting and control members is gained. Thus, the shed space is better used, particularly in proximity of the binding point. With such shaping of the dents, it is possible to use the space below the guiding channel for mounting the whole auziliary blowing nozzle mechanism, thus making free the actual space in front of the reed dents. This is advantageous particularly for the structure and arrangement of temples for the fabric being formed, which must be placed as near as possible to the binding point. A further advantage of the device according to the present invention consists in that by shaping out a part of the dents, this part gains a higher rigidity.This is important particularly when weaving closely woven fabrics.

An advantage of an embodiment according to the present invention consists in that by forming a labyrinthshaped riding over slot, the sucking effect from the channel is reduced.

Thus, the advancement of the weft during insertion becomes more smooth, waveless and loopless. Moreover, the possibility of overrunning of warp threads upon entering of the guiding channel into the lower branch of the warp threads is reduced. This causes a higher reliability of the machine during weaving and produces a higher quality of the fabric.

Embodiments of the present invention by way of example will now be described with reference to the accompanying drawings, in which: Figure 1 is an overall perspective view of a pneumatic weaving machine, Figures 2 to 11 are side views of various types of dents with guiding channels for the machine of Fig. 1, Figures 1 2 to 14 show various embodiments of reed dents without guiding channels, to which the bodies of auxiliary nozzles are attached, and Figures 1 5 to 22 show various embodiments of dents in which the bending forms a labyrinth-shaped riding over slot.

The pneumatic weaving machine as shown in Fig. 1 is provided with a supply bobbin 1 mounted on the machine frame 2, from which the weft 3 is withdrawn during weaving by the measuring mechanism 4. Therefrom, the weft 3 is guided via tongues (not shown) into the main inserting nozzle 5. The beat-up reed 6 is mounted on a slay carrier frame (not shown), the reed being formed of profiled dents 7. From the beat-up side 18, the separate dents 7 are formed in such manner, that they form a closed guiding channel 8 with a riding over slot 9. In front of the initial part of guiding channel 8, a cutter or scissors 10 are mounted from the side of the main inserting nozzle 5, and at the end of channel 8 a sucking device 11 is provided which may be of the ejector type.Along the length of guiding channel 8, the bodies of auxiliary nozzles 1 2 are mounted near the dents 7, and are directed into channel 8 by their outlet openings (not shown). Both the main and the auxiliary nozzles 5, 12, and possibly also the sucking device 11 are connected with their supplies 1 3 to an air conduit 14. Each supply 1 3 is provided in the proximity of both the main and the auxiliary nozzles 5, 1 2 and the sucking device 11 with an electromagnetic valve 1 5. For the purpose of sensing and controllong the operation of the weaving machine, the valves are provided with a checking device 1 6 with sensors (not shown). In Figs. 2 to 11, various emobidments of the shaping out of one or more parts of the dent 7 in various positions relative to the guiding channel 8 are shown.

Figs. 2, 3 and 4 show embodiments, in which the shaping of the dent 7 of the reed 6 is performed at the point of the riding over slot 9 of guiding channel 8. The difference of embodiments consists in that in Fig. 2, the adjacent wall of guiding channel 8 to the beat-up side 18 of dent 7 follows the shaping out along its whole length, while in Fig. 3 only up to the half of its length.

In Fig. 4, the adjacent wall of the channel 8 forms a continuous rectilinear continuation of the not shaped out part of the beat-up side 1 8 of dent 7.

In Figs. 5, 6 and 7 embodiments are shown, in which the shaping out of the dent 7 is made at the point of the guiding channel 8. The difference between Fig. 5 and 6 is that, in Fig. 5 the body of auxiliary nozzle 12 forms the continuation of the rectilinear beatup side 18 of dent 7, while in Fig. 6 the body of the auxiliary nozzle 1 2 is adjacent to the bent-out part of dents 7 which forms one wall of guiding channel 8.

In Fig. 7, the adjacent wall of channel 8 forms a continuous continuation of a not shaped out beat-up side 18 of dent 7.

Figs. 8, 9 and 10 show an embodiment, in which the shaping out of dent 7 is performed at the point of the lower foot of guiding channel 8.

Fig. 8 is a guiding channel 8 of trapezoidal shape with the body of the auxiliary nozzle 1 2 adjacent to its rear wall.

Fig. 9 has the guiding channel 8 of triangular shape, the bodies of auziliary nozzles 1 2 being adjacent to the rectilinear part of dents 7 at the point of the rear side of guiding channel 8.

In Fig. 10, a shaping out from the binding point 21 of substantially both parts of the dents in one point of the lower foot of the guiding channel 8 of triangular shape is performed.

Fig. 11 shows an embodiment, in which the dents 7 are shaped out at two points, i.e.

at the point of the riding over slot 9 and at the point of the lower foot of guiding channel 8.

The object of the present invention is not restricted to the above exemplary embodiments, but includes all possible embodiments within the scope of the present invention, as the shape of the guiding channel 8 on the shaped out dent 7 might be arbitrary. Also the shaping out of dents 7 need not be rectilinear, but can be formed by e.g. an arch or a curve. The rear part of dent 7 need not only follow the shaping out of the front side, but the thickness of dents 7 can be increased at the point of channel 8 and the beat-up part, or the rear part might be formed by a straight line between its insertion. The bodies of the auxiliary nozzles 1 2 might be formed either by a rectilinear stick or, as partially represented, a stick with a bending following at least at the point of guiding channel 8 the shaping out of dent 7.Furthermore, the bodies of the auxiliary nozzles 1 2 might be formed in the shape of the guiding channel 8 or, at one point of reed 6, two bodies of auxiliary nozzles 1 2 might be formed, one thereof attached to dent 7 and the other formed at the point of the front part of guiding channel 8. The bodies of auxiliary nozzles 1 2 can be formed also in the conventional manner, i.e. coming from the front part from the binding point 21 into the upper part of the guiding channel 8 towards the riding over slot 9.The bodies of auxiliary nozzles 1 2 might have one or several discharge openings 1 9. At the point of inserted bodies of auxiliary nozzles 12, the attached dents 7 of reed 6 have not formed a guiding channel 8, but are either congruent with their original shape or with their front outline at the point of the guiding channel 8 with its rear wall, as shown in Figs. 1 2 and 1 3. The dents 7 can also have a shape permitting an optimum insertion of the bodies of auxiliary nozzles 1 2 and their direction into the guiding channel 8. However, their beat-up side 1 8 must be identical with the beat-up side of the remaining dents 7 with the formed channel 8, as follows from Fig. 14.

In Figs. 15 to 22, embodiments of riding over slots 9 of the guiding channels 8 formed at the shaping out point on the dents 7 are shown.

Fig. 1 5 shows an embodiment, in which the rear wall 20 of guiding channel 8, which is most remote from the binding point 21, is offset from the beat-up side 1 8 to the binding point 21, its connection line and the front.end of the beatup side 1 8 forming together with the end of the upper side of guiding channel 8 a labyrinth-shaped riding over slot 9 by shaping out.

Fig. 1 6 shows an alternative embodiment of the labyrinth-shaped riding over slot 9.

Fig. 1 7 is an embodiment having an arcuate shaped labyrinthine riding over slot 9 with a partial shaping out of dent 7.

In Fig. 18, a labyrinth-shpaed riding over slot 9 is formed by an arcuate shaped dent 7.

In Fig. 19, in the lower part a once shaped out dent 7 is situated, where the rear wall 20 of channel 8, which is most remote from the binding point 21, is offset from the rectilinear beat-up side 1 8 outwards towards the binding point 21, while their connecting line forms by a further shaped one side of the inclined labyrinthine riding over slot 9.

In Fig. 20, an alternative embodiment is shown, in which the inclined connecting line of the rectilinear beat-up side 1 8 and the rear wall 20 of the channel 8, forming one side of the labyrinthine riding over slot 9 is extended, thus forming a partial shaping out of the beatup side 18 of dent 7.

Fig. 21 shows an embodiment with an inclined shaped out beat-up side 1 8 of dent 7, where the rear wall 29 of the guiding channel 8 is offset ahead towards the projecting part of guiding channel 8. The connecting line of the beat-up side 1 8 and the rear wall 20 of channel 8 forms one part and the front end of the shaping out of dent 7 the other part of one side of the labyrinthine riding slot 9. The second part of slot 9 is formed by the free end of the projecting part of channel 8.

Embodiments of the present invention can be used in pneumatic or jet weaving machines.

Claims

1. A device for forming fabric in a pneumatic or jet weaving machine, comprising a beatup reed having profiled dents forming a substantially closed guiding channel for the weft with a riding over slot or gap, a main nozzle mounted in proximity of the front end of the guiding channel and auxiliary nozzles distributed in the reed at predetermined distances, their exit openings being directed in the direction of weft insertion inclined into the channel, wherein from the beat-up side of the reed at least one dent is shaped out in a direction away from the binding point in at least a part of its length.

2. A device as claimed in Claim 1, wherein the dents are shaped out at the point of the guiding channel.

3. A device as claimed in Claim 1, wherein the shaping out is performed at the point of the riding out slot or gap.

4. A device as claimed in Claims 1 and 3, wherein the shaping out of the dent forms at least a part of a labyrinth-shaped riding out slot or gap.

5. A device as claimed in Claims 1, 3 and 4 wherein one wall of the labyrinth-shaped riding out slot is formed by a partial shaping out between the beat-up side and an offset rear wall of the guiding channel.

6. A device as claimed in Claims 1 and 2 wherein bodies of auxiliary nozzles are introduced into a lower part of the guiding channel from downside in the direction towards the riding out slot.

7. A device as claimed in Claims 1, 2 and 3 wherein to at least a part of a length of a rear side of the guiding channel in at least one dent there is attached an auxiliary nozzle.

8. A dent for a pneumatic or jet weaving machine substantially as described with reference to any one of Figures 2 to 22 of the accompanying drawings.

9. A pneumatic or jet weaving machine substantially as described with reference to Fig. 1 of the accompanying drawings.