GB2182361A

GB2182361A - Weft guide for jet loom

Info

Publication number: GB2182361A
Application number: GB08625379A
Authority: GB
Inventors: Josef Joch; Vladimir Kuda; Vaclav Jadrny; Karel Vystrcil; Jiri Cernocky; Josef Martinec
Original assignee: VYZK VYVOJOVY USTAV
Current assignee: VYZK VYVOJOVY USTAV
Priority date: 1985-10-23
Filing date: 1986-10-23
Publication date: 1987-05-13
Also published as: CS886487A1; GB8625379D0; CS267133B1; GB2182361B; CS265842B1; CS641187A1; IT1218920B; FR2593526B1; CS757785A1; CS256450B1; IT8622113A0; JPS62177256A; FR2593526A1; CH672336A5; ES2002880A6; DE3636103A1

Abstract

A weft inserting mechanism for jet weaving machines, in which the weft 20 is inserted into the open warp shed 3 from a main nozzle and has a system of auxiliary nozzles 23 arranged along the path of the weft to be inserted and pointed in the direction of its insertion, comprises a weft inserting channel having a cross-sectional profile which has an opening pointed in the direction of the fell 9 and being defined by on the one hand, the picking channel 17 on the shaped teeth 7 of a beat-up reed 6 and on the other hand by lower warp threads 2 of an opened shed 3. Below the lower warp threads 2 along the path of the weft to be inserted, a takeup bar 22 is arranged on a slay 14 adjacent the teeth 7 of the beat-up reed 6 and adapted to engage the lower warp threads 2. Several embodiments are described. <IMAGE>

Description

SPECIFICATION Weft inserting mechanism for jet weaving machine The present invention relates to a weft inserting mechanism for jet weaving machines, in which the weft is inserted into the warp shed by a jet of weft inserting fluid.

In the jet weaving machines hitherto known the weft is inserted into the space between the upper and lower warp threads of the open warp shed and 'beaten-up' by the teeth of the beat-up reed to the interlacing point at the edge of the newly forming cloth. The inserting fluid jet, usually air is introduced by a main nozzle and also by auxiliary nozzles which are arranged along the path of the inserted weft and pointed in the direction of its insertion. This arrangement while simple, is characterised by an abundently high consumption of weft inserting fluid together with a considerable number of short picks which result in looping of the weft and similar defects in the fabric.

As an improvement on this system, several known jet weaving machines are provided with a beat-up reed on which the teeth are shaped with an open picking channel, eg. in the form of a horizontally disposed U-shape, with the open end of the 'U' pointing towards the face of the fabric being produced. The beat-up of the inserted weft towards the front of the fabric is performed by the rear wall of the U-shaped picking channel of the reed teeth.

This type of weft inserting arrangement consumes considerable amounts of inserting fluid and does not prevent the aforementioned failures in the fabric. A further disadvantage lies in the requirement for higher accuracy in producing the channelled teeth of the reed and the reed itself.

Afurther known type of weft inserting arrangement has, for the purpose of preventing the weft inserting fluid passing through the gaps between both the upper and lower warp threads in the open shed, mounted on both the upper and lower reed hull, inclined shielding gliders which are parallel with the upper and lower warp threads on maximum opening of the shed. Between the reed and the first heald shaft further screens are mounted which may be rotated about a vertical axis and cover the open shed. Each of the said screens is mounted on a rod which may be angularly displaced by a lever mechanism. Further short shielding gliders are provided. The main disadvantage of this type of arrangement is its complexity which puts high requirements on manufacturing technology, assembly, adjustment, operation and maintenance.

The disadvantages and shortcomings of the abovementioned weft inserting arrangements are eliminated to a substantiai extent by a weft inserting mechanism for a jet weaving machine in accordance with the present invention wherein the weft is inserted by means of a jet of inserting fluid from a main nozzle and also from a system of auxiliary nozzles which are arranged along the path of weft insertion and pointed in the direction of weft insertion, the mechanism being so dimensioned and arranged to provide a weft inserting channel having an opening and being defined by on the one hand a picking channel on the shaped teeth of a beat-up reed and on the other hand by lower warp threads of an opened shed, characterised in that below the lower warp threads of the open shed, a take-up bar is arranged adjacent the teeth of the beat-up reed along the path of the inserted weft, in that the upper surface of said bar is adapted to engage the lower warp threads, and in that the auxiliary nozzles are positioned within the open shed above the upper surface of the bar.

The cross-section of the weft inserting channel is shaped to have an opening pointing in the direction towards the interlacing point.

A weft inserting mechanism in accordance with the invention has the advantage that the efficiency of weft insertion is increased by simultaneously increasing the weft insertion velocity and reducing the consumption of weft insertion fluid for example by minimising fluid loss through the lower warp threads. Furthermore, the invention is simple in its construction, easy to manufacture and easily adjustable during operation.

The invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a weaving machine in accordance with the present invention, displaying the weaving mechanism, Figure 2 is a side cross-section view of the machine of Figure 1 as taken through the weft inserting channel as defined by the take-up bar in the position at the beginning or the end of weft insertion, Figure 3 is a side cross-section view of the machine of Figure 1 as taken through the weft inserting channel as defined by the take-up bar with the reed at its furthest position from the interlacing point, Figures 4to 10 are side cross-section views of alternative embodiments of weft insertion channels as defined by take-up bars, with the take-up bars in a stationary position, and Figures 11 to 15 are side cross-section views of further embodiments of weft insertion channels in which take-up bars controllably change their position in the course of weaving.

In the weaving machine shown in Figure 1, both the upper and lower warp threads 1 and 2 forming the shed 3 are fed from a warp beam (not shown).

The warp threads 1 and 2 pass through the healds 6 on the heald shafts 5 and 8, the position of which is controlled by a heald mechanism (not shown). The warp threads 1 and 2 also pass through the beat-up reed 6, said reed having teeth 7 which are so shaped to provide a picking channel 17 by which the weft is pushed to the interlacing point 9 where the face of the fabric 10 is formed. From the interlacing point the warp threads that now form part of the fabric 10 are guided by temple 11 and a ductile beam (not shown) to the cloth beam.

The beat-up reed 6 is mounted in groove 12 which is formed in the slay 14 and is fastened there by means of screws 13. Slay 14togetherwith beat-up reed 6 is fastened to slay swords 15 which are arranged on swing shaft 16, performing together therewith a swinging motion from the beat-up position (shown dashed position in Figure 3) into the weft inserting position shown in Figures 2 and 3.

In the various embodiments shown in Figures 2 to 15, the teeth 7 on the beat-up reed 6 are shaped to have a picking channel 17, formed by nose-shaped projections 18 on the teeth 7, and rectilinear vertical parts 19, also on the teeth 7 or beat-up reed 6. The opening of the picking channel 17 is directed towards the interlacing point 9 and forms part of the wall of the weft inserting channel through which the weft 20 is inserted and this defines part of its crosssectioned profile. The cross-section of the weft inserting channel is further defined by the lower warp threads 2 of the open shed 3. The main inserting nozzle 21 on slay 14 is mounted at the inlet to the weft inserting channel, said nozzle being connected to a pressurized fluid distributor (not shown).Below the lower warp threads 2, a take-up bar 22 is situated along the path of the inserted weft 20, on the slay 14 adjacent the rectilinear vertical part 19 of the teeth on the beat-up reed. Above the upper surface of said take-up bar 22, which is adjacent the lower warp threads 2 of the open shed 3, the auxiliary nozzles 23 are positioned within the open shed.

In the various examples shown in Figures 2 to 15, the auxiliary nozzles 23 are fitted directly into the Tshaped groove 24 of slay 14 and are adjustable along the path of the weft 20 to be inserted. The nozzles are connected by pressure hose 25 to a pressurised fluid distributor (not shown).

In Figures 2,3,4 and 5, a weft inserting mechanism is shown where the take-up bar 22 is Ushaped in cross-section. One arm 26 is adapted to engage the lower warp threads 2 of the open shed 3.

The central connecting part 27 is positioned adjacent the teeth of the beat-up reed 6 and the second arm 28 of the take-up bar 22 is removably attached to the slay 14 of the weaving machine by means, for example of screws, through intermediate replaceable distance washers. By means of the replaceable distance washers 29, it is possible to adjust the take-up bar towards and away from the shaped picking channel 17 on the teeth 7 of the beatup reed 6 and therefore to establish the most suitable cross-sectioned profile of the weft channel for a given kind of inserted weft 20 and warp threads 1 and 2. For the majority of weft yarns 20 it is best, for at least part of the time weft is being inserted, to have the take-up bar 22 in supporting engagement with the lower warp threads 2 of the open shed 3.

For each kind of weft 20, the optimum position of the take-up bar 22 depends on the pressure valve and the quantity of entraining pressure fluid, fed by the main inserting nozzle 21 and the auxiliary nozzles 23.

In Figures 2,3 and 4 the planar upper surface of the take-up bar 22 is directed away from the lower warp threads 2 of the open shed 3 and makes an angle a with the plane through the rectilinear parts 19 of the teeth of the reed, which is in the range 75105. In Figures 2 and 3 the angle a = 90" and in Figure 4 a = 75 . In Figure 5 the upper surface of the take-up bar 22 is adapted to engage to the lower warp threads 2 and made in the form of a semicylinder, the axis of which is parallel to the path of the weft being inserted.

In Figure 6 a weft inserting mechanism is shown where the cross-sectional profile of the take-up bar 22 is L-shaped, and arm 30 is adapted to engage the lower warp threads 2 of the open shed 3, while the other arm 31 is fastened to the beat-up reed 6 on replaceable distance washers 32 in groove 12 of the slay 14 by means of fastening screw 13.

In Figure 7 a weft inserting mechanism is shown which is similar to previous described embodiments but in this case the take-up bar 22 is adapted to engage to the lower warp threads and has, on at least part of its upper surface, an antiabrasive packing piece 33, for example of sintered corundum.

Similarly, it is possible to provide at least a part of the upper surface ofthetake-up bar 22 with an antiabrasive layer.

Figure 8 shows a weft inserting mechanism in accordance with Figures 2 and 3. However, the takeup bar is wider and is provided with through holes 34 for the auxiliary nozzles 23. Afurther embodiment of the weft inserting mechanism is shown in Figure 9. The take-up bar is mounted on support members 35 which in turn are mounted displaceably in the guideway 36 made in slay 14 of the weaving machine. The take-up bar is fixed in its adjusted position by detent screws 37. A similar embodiment is shown in Figure 10. The take-up bar 22 is mounted on supporting members 35 and is displaceable in guideway 36 under the action of a compression spring 38. The support member 35 meets, at its lower end, a bearing with adjustable stops, comprising for example adjusting nuts 39 on the supporting members 35 and guideway faces 40 of the displaceable guideway 36.

In Figures 10 to 14, further embodiments of weft inserting mechanism are shown, the take-up bars 22 thereof being adapted to adjust away from the weft insertion position so that opening of the weft inserting channel is reduced and then extended when the reed is in the beat-up position. Such embodiments are particularly advantageous when, for a given kind of weft, the take-up bar is, at least for part of the insertion time, in supporting engagement with the lower warp threads 2 of the opened shed 3. By reducing the supporting engagement to a minimum, the lower warp threads are advantageously saved from abrasion.

In Figures 11,12,13and 14thetake-upbaris mounted on supporting members 35 which are displaceably mounted in guideway 36 as previously described but their movement is controlled differently. In the embodiment in Figure 11 at least two of supporting members 35 are provided with a roller 41 and are spring loaded by a spring 42 into engagement with a cam surface 43 which can be adjusted in height in order to adjust the weft insertion position of the take-up bar 22.

In Figure 12 the supporting members 35 are spring loaded by spring 46 into the beat-up position of the take-up bar 22, at least two of the supporting members having at their lower end a piston 44 which is displaceable in cylinder 45, the cylinder being connected to the means for controlling the distribution of pressurised fluid, for example the distribution of the fluid carrying weft 20.

In Figure 13 at least two of the supporting members 35 are provided with a double acting piston 47 which is displaceable inside cylinder 48, the space above and below piston 47 being connected independently to the means for the controlled distribution of pressurised fluid. The weft inserting position of take-up bar 22 can be adjusted by changing its position on the supporting member 35.

The example in Figure 14 is in accordance with that shown in Figure 12 except that the auxiliary nozzles 23 are mounted directly on the take-up bar 22 by means of a carrier 50 and thus may change their position with the take-up bar.

In Figure 15 the take-up bar 22 is mounted on the slay 14 of the weaving machine by means of swing support pins 49 which allow it to swing from the inserting position to the beat-up position, the swinging motion being coupled to the weaving motion of the slay 14. The take-up bar 22 assumes the inserting position by change of position of the pins 49. During weaving the slay 14 is swung out firstly towards the inserting position. At the point of weft insertion when the weft 20 is projected from the main nozzle 21 into the weft insertion channel, the take-up bar 22 approaches the position shown in Figure 2 or may, according to the way in which it is adjusted, be in supporting engagement with the lower warp threads 2. In the next phase of weft insertion the slay 14 moves as shown in Figure 3 to its extreme back position. In the final phase of weft insertion the slay 14 swings back to the beat-up position and as shown in Figure 2, the take-up bar 22 moves away from the lower warp threads 2. The inserted weft 20 is then beaten up by the beat-up reed 6 into the interlacing point 9 and interlaced by the warp threads 1 and 2. The whole cycle is then repeated.

Claims

1. A weft inserting mechanism for a jet weaving machine wherein the weft is inserted by means of a jet of inserting fluid from a main nozzle and also from a system of auxiliary nozzles which are arranged along the path of weft insertion and pointed in the direction of weft insertion the mechanism being so dimensioned and arranged to provide a weft inserting channel having an opening and being defined by on the one hand a picking channel on the shaped teeth of a beat-up reed and on the other hand by lower warp threads of an opened shed, characterised in that below the warp threads of the open shed, a take-up bar is arranged adjacent the teeth of the beat-up reed along the path of the inserted weft, in that the upper surface of the bar is adapted to engage the lower warp threads, and in that the auxiliary nozzles are positioned within the open shed above the upper surface of the bar.

2. A weft inserting mechanism as claimed in Claim 1, characterised in that the take-up bar may be moved towards the picking channel of the teeth of the reed in order to reduce the opening of the crosssectional profile.

3. Aweft inserting mechanism as claimed in Claim 2, characterised in that the take-up bar is mounted on the slay of the weaving machine on replaceable distance washers such that its height may be adjusted.

4. A weft inserting mechanism as claimed in Claim 3, characterised in that the cross-sectional profile of the take-up bar is U-shaped, having one arm adapted to engage the lower warp threads of the open shed, a central connecting part disposed adjacent the teeth of the beat-up reed and the other arm removably mounted by replaceable distance washers on the slay of the weaving machine.

5. A weft inserting mechanism as claimed in Claim 3, characterised in that the cross-section profile of the take-up bar is L-shaped, and one arm thereof is adapted to engage the lower warp threads of the open shed while the other arm is fixed on replaceable distance washers on the beat-up reed which is mounted in the groove of the slay of the weaving machine.

6. A weft inserting mechanism as claimed in Claim 3, characterised in that the take-up bar is mounted on supporting members which in turn are displaceably mounted in guideways on the slay of the weaving machine and held in the adjusted position by, for example, detent screws.

7. A weft inserting mechanism as claimed in Claim 3, characterised in that the take-up bar is mounted on supporting members which are in turn displaceably mounted in guideways on the slay of the weaving machine under the action of springs, said supporting members being displaceable by engaging with stops formed, for example, by adjusting nuts on supporting members and the faces of the displaceable guideways.

8. Aweft inserting mechanism as claimed in any preceding claim characterised in that thetake-up bar is adapted to be positively displaceable from the weft inserting position, in which it reduces the opening of the channel, to the beat-up position, in which the opening of the channel is extended.

9. A weft inserting mechanism as claimed in Claims 2 and 8, characterised in that the take-up bar is mounted on supporting members, displaceably mounted in a guideway on the slay of the weaving machine, of which at least two are provided with a roller and are spring loaded into engagement with a cam surface.

10. A weft inserting mechanism as claimed in Claims 2 and 8, characterised in that the take-up bar is mounted on supporting members which are displaceably mounted in the guideway on the slay of the weaving machine, the supporting members being spring loaded into the beat-up position, at least two of said supporting members having at their lower end a piston, which is guided inside a cylinder, the cylinder being connected to controlled pressure fluid distribution means.

11. A weft inserting mechanism as claimed in Claims 2 and 8, characterised in that the take-up bar is mounted on supporting members which are in turn mounted in the guideway on the slay of the weaving machine and of which at least two supporting members having provided at their lower end a double acting piston guided inside a cylinder, in which both the space above and below the piston are connected to controlled pressure fluid distribution means.

12. Aweft inserting mechanism as claimed in Claims 2 and 8, characterised in that the take-up bar is mounted on the slay of the weaving machine such that it is swingable from the insertion position to the beat-up position and is drive-coupled with the weaving motion of the slay.

13. A weft inserting mechanism as claimed in Claims 1 to 12, characterised in that the auxiliary nozzles are mounted on the take-up bar.

14. A weft inserting mechanism as claimed in Claims 1 to 13, characterised in that the take-up bar is, at least for a part of the time of weft insertion, in supporting engagement with the lower warp threads of the open shed.

15. A weft inserting mechanism as claimed in Claims 1 to 14, characterised in that the upper surface of the take-up bar which is adapted to engage the lower warp threads on the open shed, is flat and makes a, in the range 75 to 105'with a plane laid through the rectilinear part of the teeth of the reed.

16. A weft inserting mechanism as claimed in Claims 1 to 14, characterised in that the upper surface of the take-up bar, which is adapted to engage the lower warp threads of the open shed, has the shape of a semi-cylinder of which the axis is parallel to the path of the inserted weft.

17. A weft inserting mechanism as claimed in Claims 15 and 16, characterised in that the take-up bar is provided with through holes for the auxiliary nozzles.

18. A weft inserting mechanism as claimed in Claims 1 to 17,characterised in that at least a part of the upper surface of the take-up bar, which is adapted to engage the lower warp threads of the open shed, is provided with a non-abrasive layer.

19. A weft inserting mechanism as claimed in 1 to 17, characterised in that the take-up bar, which is conversely directed to the lower warp threads of the open shed, is on at least a part of its upper surface provided with a packing of anti-abrasive material.