JPS5838544B2 - Shyokuki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a loom in which a weft yarn is passed through a shed by a fluid flow from a weft insertion blow nozzle.

In the known loom, a weft thread transport path is delimited by a plurality of approximately U-shaped vanes movable integrally with the shed, and the weft thread is passed through said transport path from one side of the shed to the other side. Directed by the flow of fluid from the weft insertion blow nozzle on one side of the shed, a tensioning device is provided on the other side of the shed to pull the weft thread after it has been inserted into the shed, and pull the weft thread of the bracket. is adapted to be held in tension during the reed reeling motion.

In conventional looms, the tensioning device on the other side of the shed was of the suction nozzle type that sucked and pulled the weft yarn using negative pressure, and the tensioning force was weak.

Furthermore, the position of the hollow weft yarn in the shed is spread over a wide range, and therefore the inlet opening of the suction nozzle must be enlarged, which increases the size of the tensioning device and the amount of air consumed.

An object of the present invention is to provide a loom that can obtain a large tensile force with a small-sized tension device.

To achieve this objective, according to the invention, the tensioning device consists of an air injector that tensions the weft thread by injecting compressed air in the direction of tension of the weft thread.

A tensioning device with a jet of compressed air can increase the flow rate of the air flow around the weft thread head compared to a tensioning device with negative pressure suction, so that the tensioning force is significantly increased.

Further, according to the present invention, the weft transport path is divided by a plurality of approximately U-shaped blades that can move integrally with the reed,
The weft yarn is guided along such a defined transport path, and the weft yarn is provided with a blade having an extension portion extending beyond the shed by a predetermined distance on the side remote from the weft yarn insertion blow nozzle. However, an air injector as a tensioning device is mounted longitudinally adjustable in the conveying channel in the reed extension.

If the tensioning device and the blowing nozzle for weft thread insertion are simply provided on both sides of the shed, the position of the tip of the weft thread passing through the shed will vary, and as a result, the weft thread inlet of the air injector as the tensioning device will be It is necessary to increase the size of the weft yarn in the shed, which causes problems such as increasing the size of the air injector and increasing the amount of compressed air injected to obtain the same tensile force. The transport route is defined by the grooves of the reed blades, thereby limiting the position of the tip of the weft yarn that has passed through the shed to an extremely narrow range, and the air injector is installed on the extension of such transport route. , the air injector can be made smaller and the consumption of compressed air can be reduced.

It should be noted that the cross-section of the tunnel-like transport path delimited by the U-shaped vanes is, for example, less than 8 mm, so that the inlet opening of the air injector can also be less than about 8Tt7IL.

Note that normally one or more auxiliary air blowing nozzles are provided along the width direction of the loom, and the auxiliary air blowing nozzles assist the transport of the weft yarn in the tunnel-like transport path.

Further, in the present invention, since the detection device for detecting that the weft yarn is inserted into the transport path is provided on the wall of the air injector, the detection accuracy of the detection device can be improved.

That is, the detection device is equipped with a light source and a photoelectric receiver that receives the light from the light source, and when the position of the weft yarn in the transportation path changes significantly, it regulates the movement of the weft yarn in a direction transverse to the transportation direction. Although it is necessary to ensure that the weft yarn intercepts the light beam from the light source, in the present invention the air injector automatically defines the transverse movement of the weft yarn.

Experiments have also shown that the air injector imparts a predetermined twist to the weft yarn, making it balloon-like.

Due to this small balloon shape, the weft thread tensioned in the relatively small cross-section of the air injector intercepts in any case the light beam directed in the diametrical direction of said cross-section;
The detection accuracy of the detection device is further improved.

Next, reference will be made to the accompanying drawings showing one embodiment of the present invention.

In FIG. 1, the tunnel-like transport path for feeding the weft yarn opens toward the reversing line 4 in a shed 3 formed by the upper and lower warp yarns 1 and 2, and is accommodated in the reversing beam 6. It is formed by a substantially U-shaped reed blade 5.

A mackerel with a reed beam 6 having reed blades 5 is shown in the retracted position of the reel in FIG. The weft thread insertion (air blowing) nozzle 1 is arranged opposite to the weft thread insertion (air blowing) nozzle 1 which introduces the weft thread into the tunnel.

Since the loom should normally be capable of weaving fabrics of different widths, the side of the loom that is far from the weft blowing nozzle 7 generally has the corresponding edges of the fabric at various distances. extends beyond.

At the end of the reed extending beyond the side edges of the fabric, an air injector 8 is attached to the reed beam 6 by means of a coupling bracket 9 and is adjustable across the width of the fabric.

The air injector 8 has a known construction, as shown in longitudinal section in FIG. 2, and corresponds to the construction of the weft yarn blowing nozzle 7.

This air injector 8 receives the weft thread ejected from the weft thread insertion nozzle 7 and holds it under tension during the beating movement of the reed.

For this reason, the air injector 8 is supplied with air at the same time as or immediately after supplying air to the blower nozzle 7 until at least the end of the reed reed beating operation.

The flexible air hose connection to this air injector 8 is shown at 9'.

When retracting the reed, the end of the weft thread inserted into the cloth is pulled out of the air jet 8, and this end can be received in a suction nozzle in a known manner or subsequently cut with a cutting tool. good.

It is essential that the length of the end of the weft thread extending beyond the edge of the fabric in this case is short and therefore not longer than the distance that the air injector 8 travels between the reversing position and the retraction position. .

This ensures that the end of the weft thread is released from the air injector 8.

The air injector 8 further forms an element of a weft thread detection device consisting of a light source 10 and a light source receiver 11.

The light source 10 may be a small light source, such as a miniature light bulb, Ga-A, S diode, etc., and may be attached directly to the tube wall of the air discharge tube 8' of the air injector 8, or installed in a radial hole in the tube wall. It may also be optically connected to the inserted optical fiber.

The photoelectric receiver 11 is, for example, a light emitting diode placed opposite a light source 10 in the wall of the air outlet pipe 8'.

Even if the light beam emitted diametrically from the light source 10 and passing through the air discharge tube 8' passes through only a very narrow part of the cross section (approximately 3 mm) of this discharge tube, it is ensured that the weft thread captured by the air injector 8 still remains in the light beam. As a result of this interruption of the light flux, the light emitting diode 11 generates a signal indicating that the weft thread has indeed been inserted from the other side of the loom.

This signal may be converted by an amplifier 12, as shown in FIG. 2, into a signal that energizes the electrical circuitry that drives the loom.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the reed of an air loom equipped with a weft thread tensioning device according to the present invention, and Fig. 2 is a longitudinal sectional view of the weft thread tensioning device according to the invention, also showing the electric circuit of the weft thread detection device. be. 1...Upper warp thread, 2...Lower warp thread, 3...Hole, 4...Reel striking line, 5
...Osa feather, 6...Osa beam, 7
...Weft thread insertion nozzle, 8 ... Air injector, 10 ... Light source, 11 ... Photoelectric receiver.

Claims (1)

[Claims] 1. A transport path for the weft yarn is defined by a plurality of approximately U-shaped vanes movable integrally with the reed, and the weft yarn passes through said transport path from one side of the shed to the other side of the shed. guided by a fluid flow by a weft thread insertion blow nozzle on one side of the shed, and a tensioning device is provided on the other side of the shed;
In a loom which is designed to pull the weft thread after it has been inserted into the shed and to hold the weft thread in tension during the beating movement of the reed, the reed thread provided with vanes is an extension extending beyond the shed by a predetermined distance on the side remote from the insertion blow nozzle;
The air injector, which pulls the weft thread by injecting compressed air in the direction of the weft tension, is longitudinally adjustable in the transport channel within the reed extension and is equipped with a light source and a photoelectric receiver. A loom, characterized in that a detection device for detecting insertion of the weft yarn into the transport path is provided on the wall of the air injector.