GB2161503A

GB2161503A - Confusor for a jet loom

Info

Publication number: GB2161503A
Application number: GB08514276A
Authority: GB
Inventors: Zdenek Horak; Jiri Vystrcil
Original assignee: VYZK VYVOJOVY USTAV
Current assignee: VYZK VYVOJOVY USTAV
Priority date: 1984-06-06
Filing date: 1985-06-06
Publication date: 1986-01-15
Also published as: GB8514276D0; FR2565606A1; IT1186734B; DE3520468A1; IT8521052A0; CS427984A1; CS253056B1; GB2161503B; JPS6147850A

Abstract

In a jet loom the guide channel or confusor for the weft is formed with a section having at least three planar walls. Several embodiments are shown. <IMAGE>

Description

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

The devices for forming fabrics hitherto known use various types of guiding channels and, together therewith, also beat-up mechanism reeds. A device is known, in which the guiding channel consists of guiding plates with orifices, which are fixed on the carrier beam of the beat-up mechanism batten. Behind the channel a beat-up reed, consisting of linear dents mounted in a reed frame, is fixed in the direction from the beat-up in a batten carrier beam. Between each dent, either one or a plurality of threads are guided on the weaving machine, which are thus continuously distributed by the dents. The guiding plates with orifices are thicker than the reed dents, and therefore there are fewer of these than the reed dents.During weaving, when the shed is opened and the reed moves back from the beat-up, the warp threads are by that means evenly distributed and the guiding plates with orifices enter the shed from below.

Because the guiding plates with orifices of the guiding channel are thicker and less in number along the reed length, the number of warp threads in the gap therebetween cannot be the same as in the reed. Thus, they are again distributed and bundled. The warp threads are re-distributed by the guiding plates with orifices and into one gap therebetween there must be more warp threads than between the reed dents. This is disadvantageous as just here warp thread breakages or their damaging is encountered due to their pinning up by guiding plates with orifices of the guiding channel. This disadvantage appears particularly with twistless or low twist yarns, and also monofilament yarns, from which the separate particles are drawn out from the fibre by the guiding plate.Upon moving the reed into the beat-up position, the weft yarn is removed from the guiding channel with its guiding plates against leaves the warp threads. The weft is then caught up by the linear reed dents and beaten up into the binding point.

A further disadvantage of the above arrangement is the gap between the guiding channel and the beat-up reed is diminished because of the applicable inserting angle of the guiding channel.

Another known embodiment of the fabric forming device has an open guiding channel, which is constituted by profiled dents of the beat-up reed. The guiding channel has the shape of an inclined opened letter U, in which the missing outer channel wall is substituted during weft insertion by auxiliary nozzles distributed along the whole length thereof. The warp threads are distributed between the profiled dents. During weaving, the separate warp threads are thus continuously and evenly distributed. The weft is introduced into the guiding channel by the main nozzle, and transported further by means of auxiliary nozzles. The pressure fluid flow leaving the nozzles simultaneously closes the open side of the guiding channel. Upon beating-up, the weft does not leave the open channel, as 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, this requiring a stronger pressure fluid flow. This is disadvantageous because of increased consumption of the pressure fluid, the weaving machines thus taking more power and becoming more com placated.

In another known embodiment of a device for forming fabrics, the guiding channel is also formed of profiled dents. The guiding channel is substantially of rotary shape with a semicircular front side, the opposite side being vertical and their connecting line is rectilinear and inclined downwards to the arcuate part. As a whole, the guiding channel is offset in front of the dents and is formed as far as on their projection. Thus, the rear vertical wall of the guiding channel does not pass through theplane formed by the vertical beat-up front wall of the reed dents. The bodies of the auxiliary nozzles are introduced into the gap in the guiding channel from the front side. The gap is formed in the channel in such manner, that on a defined number of dents beside each other, the guiding channel is not closed by an arcuate part.Because the guiding channel is offset from the beat-up reed in front of it, the usable insertion angle of the channel is diminished. Moreover, by reason of the symmetry of the channel, the insertion angle of the weft is diminished, whereby the time, during which the weft can be inserted into the shed, is reduced.

The above mentioned disadvantages are mitigated by a device according to the invention in which, the guiding channel is formed by at least three planar walls.

The advantage of the device according to the present invention consists in the constantly even distribution of the warp threads by the dents of the beat-up reed, and an increased extent of movement of the channel inside the shed, which can be used for weft insertion. The advantageous shape of the channel increases, on the other hand, the weft insertion angle, and this together prolongs the time of the actual weft insertion. Moreover, this can be also used for increasing the speed of the weft machine operation, in which also by increasing the rpm the usable weft insertion time remains without change relative to the known embodiments. By closing the guiding channel in the dents, the power requirements of the weaving machine are reduced.

Various embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is an overall perspective view of a pneumatic weaving machine, and Figures 2 to 16 show various embodiments of the guiding channel shape formed by reed dents for the machine of Fig. 1 The pneumatic weaving machine is provided with a thread supply 1, which is hung from the machine frame 2, wherefrom upon weaving, the weft 3 is withdrawn by a measuring mechanism 4. From this mechanism weft 3 is fed via tongs (not shown) into the main inserting nozzle 5. On the not shown carrier frame of the batten, there is mounted a beat-up reed 6 formed of profiled dents 7. On the beat-up side the separate dents 7 are shaped in such a manner, that they form a closed guiding channel 8 with an unthreading slot 9 (see Figs. 2 to 16).In front of the initial part of the guiding channel 8, on the side of the main inserting nozzle 5, a cutter 10 is mounted, and at the end of channel 8 there is a sucking device 11, e.g. of the ejector type.

Along the guiding channel 8, the bodies of auxiliary nozzles 1 2 are mounted, which open into the channel 8 with their exit openings (not shown). Both the main and the auxiliary nozzles 5, 12, and possibly also the sucking device 11 are connected through their suplies 1 3 to an air conduit 14. Each supply 1 3 in the proximity of the main and the auxiliary nozzles 5, 1 2 and also the sucking device 11 is provided with an electromagnetic valve 1 5.

For controlling and tracing the operation of the weaving machine, the valves are provided with a checking device 1 6 having sensors (not shown).

In Fig. 2 to 16, the separate and various embodiments of dents 7 of reed 6 are shown at the point forming the guiding channel 8 for the weft 3.

Fig. 2, 3 and 4 show embodiments in which channel 8 is formed of three planar walls. Figs. 5, 6 and 7 show a guiding channel 8 of the trapezoidal shape having four substantially planar walls, which is advantageous from the viewpoint of using the shed formed by warp threads 1 7. Fig. 8, 9 and 10 show embodiments derived from the trapoezoidal shape of Figs. 5 to 7, wherein there are three planar walls but one curved wall, that is one wall on the inner side forming a boundary of the channel 8 is concave. In Fig. 11 the guiding channel 8 in the dents is formed by rectilinear walls of an irregular pentagon but where five of the walls are planar. Fig. 1 2 shows an embodiment with two sides perpendicular to the rectilinear beat-up side 1 8 of the dent 7 forming continuously one side of the guiding channel 8.A connection between the two perpendicular sides is formed by an arch so that there are three sides and a curved side. In Figs. 1 3 to 16, embodiments are shown in which the guiding channel 8 is formed by the walls of an irregular hexagon at least three sides of which are planar, and in the case of Figs. 14 to 1 6 one or two sides of the projecting part of the channel is or are concave. The non-projecting side of the guiding channel 8 also need not be formed with the beat-up side 1 8 of dent 7 by a continuous straight line.

Upon weaving, the warp threads 1 7 are continuously evenly distributed by dents 7 of the beat-up reed 6. Upon opening the warp threads 1 7 of the shed, reed 6 moves in a direction away from the binding point, and the guiding channel 8 enters the shed. As the channel 8 is formed directly by dents 7, neither pinning up, nor rubbing of the warp threads 1 7 takes place. When the guiding channel 8 enters the shed, it is possible to start the insertion of weft 3. This is performed during the whole time of the backward movement of the reed towards shafts (not shown) and the following back movement to the beatup position. All that is performed, until the guiding channel 8 starts to leave the closing shed. The weft 3 is removed through the slot 9 and is beaten up by the beating-up side 1 8 of dent 7 into the binding point.

The present invention is particularly applicable to pneumatic or jet weaving machines.

Claims

1. A device for forming fabric in a pneumatic or jet weaving machine, comprising a shedding mechanism for warp threads, a beatup mechanism reed, profiled dents of which form a closed weft guiding channel with a removing gap, a main nozzle mounted in the proximity of the entrance part of the guiding channel, and auziliary nozzles distributed in the reed at predetermined distances, the exit openings of which are located in the direction of weft insertion inclined into the channel, wherein the guiding channel is formed of at least three substantially planar walls.

2. A device as claimed in Claim 1, wherein at least one of the planar beat-up walls of the dents of the reed is formed continuously as a single wall of the guiding channel.

3. A device for forming fabrics as claimed in Claim 1, wherein at least one part of at least one wall of a projecting part of the guiding channel is concave.

4. A device for forming fabric having a guiding channel formed from dents substantially as described and in accordance with any one of Figs. 2 to 1 6 of the accompanying drawings.

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