JPH103U - A damping device for the oscillation and vibration of the weft of the weft supply device of the air-type loom - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent a weft vibration coming over a discharge port yarn guide in a cutting process without changing a weft insertion time of a loom. SOLUTION: A yarn guide 4 fixed to a downstream side of the yarn guide 3 and an intermediate yarn guide 5 located in the middle of the yarn guide 3 and cooperating with a yarn guide 3 fixed to a discharge port of a weft supply device 1 are provided. The first position AA where the intermediate yarn guide 5 does not engage with the weft f in the path between the fixed yarn guides 3 and 4, and the intermediate yarn guide 5 engages with the weft f without gripping the weft f in the path. In the weft oscillation and vibration damping device, which is movable between a second position BB and a second position BB that causes the weft to deviate from the route and follow a curved path PS between the fixed yarn guides 3 and 4. An actuator 6 which operates based on the operation of the loom by an electric circuit to control the position of the intermediate yarn guide 5 is provided.
At the first position AA during the supply of the weft,
When the yarn is cut after the completion of the supply of the weft, the yarn is positioned at the second position BB.

Description

[Detailed description of the invention]

[0001]

[Industrial applications]

 This invention relates to a device for damping the oscillation and vibration of a weft in a weft supply device of an air loom.

[0002]

[Prior art]

 It is known that some of the weft supply devices of looms, especially the jet supply devices of jet looms, measure the weft of a predetermined length by an optical unit (see "Measurement of length"). The device is also generally referred to as a "weft supply device"), the device also generally comprising a magnet means in which a core adapted to the conical end of the winding drum on which the spare yarn is wound is arranged to prevent movement of the weft yarn. Stops the measured weft. A particularly effective device of this type is described in Italian Patent Application No. 20307A / 83 by the present applicant, to which reference is made in the following description.

[0003] In a device of the type described above, in particular in the device of the cited Italian application, the magnet means is used to measure the length when the thread is under tension (although of course with very little tension). The present applicant's recent test results show that this tensioned state is not always realized, and in fact, the weaving machine, and thus the weft supply device provided there, are positively guaranteed. During operation, there are times or situations in which the slightest tension necessary to properly operate the device is also lost.

[0004] It is actually recognized that the weft is under slight tension while the jets from the primary and secondary nozzles provide the tension while the weft is being fed on the loom. It can be said that one extremely delicate process of weft insertion in a weaving loom occurs when weft is cut by the cutting device located at the outlet of the main nozzle.

[0005] As is apparent from Fig. 1 schematically showing the weft insertion process in the jet loom in the attached drawing, the weft is pulled by the length measuring weft supply device 1, and aligned with the reed. It is inserted into the shed by the main nozzle 2 arranged on a movable reed frame.

[0006] The insertion of the weft starts substantially at a position A where the reed is fully opened, and at a substantially center position between that position and a position B where the reed is fully closed (reed hitting position). finish. The end of the insertion is performed by the movement prevention of the yarn by the movable body of the energized magnet as described above, and thus corresponds to the length measurement of the unwound weft. After that, the weft is cut by a cutter F arranged between the main nozzle 2 and the reed P at a position close to the reed hitting position and movable together therewith.

As is apparent from FIG. 1, in order to shorten the insertion time, the yarn guide at the discharge port of the length measuring weft supply device avoids the generation of tension due to friction on the yarn guide. At position A (the reed is fully open), it should be approximately aligned with the reed. Also, at the time of cutting when the reed is located at the position B (the reed is fully closed), the weft is pulled under tension along the range between the discharge port of the length measuring weft supply device and the woven fabric. This is because the reed is prevented from moving at both ends of the area shortly before reaching the hitting position B.

[0008] In practice, the weft is prevented from moving by the weft supply device by the magnetic means, and is stopped by the loom by closing the shed.

[0009] Thus, the excess of the weft tension is determined by the length of the path taken from the moment when the movement of the two ends of the range is prevented to the moment when the movement is cut off. At the time of cutting, an instantaneous drop in tension causes oscillation along the stretched weft, and the vibration rises from the cut end of the weft to the thread guide at the discharge port of the weft supply device, and After entering the apparatus, it extends to the yarn wound on the winding drum.

[0010] Such vibrations are transformed into strong transverse and longitudinal waves, preventing the weft from being under slight tension in the above-described operation process, and instead exposing the weft under strong vibration, and After the stop, the weft can be easily torn under the pin.

[0011] This behavior also leads to errors in the length measurement of the inserted weft, which not only leads to different patterns, but is also dangerous in all respects.

That is, usually, after the weft is inserted, one thread of the thread (although there may be a larger number of turns in a special case) passes below the magnet pin. As a result, in the case of the above-mentioned vibration, in the case of a single-color loom, there is a thread that is too long for the next insertion, and in the case of a multi-color loom, a different color is used. Will face the simultaneous insertion of two turns of yarn.

This phenomenon occurs, in particular, in the case of yarns having little elasticity. This is because the above-mentioned effects caused by the sudden drop in tension cannot be alleviated by the elasticity of the yarn. This phenomenon occurs when changing colors when working with a multicolor loom, and as the insertion of one or more turns of the same color into the same reed at the same time. Although particularly harmful because of its appearance, it cannot be prevented by the weft control systems currently used in jet looms.

By the way, if the length measuring weft supply device is arranged with respect to the loom so that friction always occurs on the yarn guide of the discharge port, or the same friction occurs between the discharge port of the weft supply device and the main unit. It has been observed that the pull-back phenomenon described above is reduced to almost extinguishing if generated by guides or rods suitable for deflecting the yarn path, placed between the nozzle and the insertion opening. . However, such an arrangement is unacceptable because it results in an increase in the insertion time as described above, while preventing the weft oscillations coming over the spout guide in the cutting process without changing the insertion time of the loom. No solution has been found to date.

[0015]

[Problems to be solved by the invention]

 The idea departs from the idea that the friction of the weft on the yarn guide has, above all, the ability to stop the vibration of the weft, and that the vibration is directed to the weft supply device immediately after cutting. Furthermore, the insertion time must not be affected, and therefore the above problem is countered in a simple and effective way, taking into account the fact that the above-mentioned friction has to be generated only for a short time during cutting. This is a solution to this.

[0016]

[Means for Solving the Problems and Their Functions and Effects]

 In order to achieve such an object, the present invention is suitable for attenuating the oscillation and vibration of the weft supplied from the weft supply device at the discharge port of the weft supply device of the loom, particularly at the time of cutting the yarn in the loom. An apparatus, wherein the apparatus cooperates with a normal first yarn guide fixed to an outlet of a weft supply device, and is fixed to a downstream side of the first yarn guide in parallel with the first yarn guide. A second yarn guide and an intermediate yarn guide positioned therebetween, wherein the intermediate yarn guide does not engage with the weft in a path between the first and second two yarn guides. A first position and, without gripping the weft in the path, engaging with the weft to deflect the weft from the path and follow a curved path between the first and second guides. Movable to and from the second position The apparatus further includes an actuator that operates based on the operation of the loom by an electric circuit of the weft supply device to control the position of the intermediate yarn guide, and the actuator controls the position of the intermediate yarn during supply of the weft. While the yarn guide is located at the first position where it does not engage with the weft, the intermediate yarn guide is located at the second position where the intermediate yarn guide is deflected without gripping the weft when the yarn is cut after the supply of the weft is completed. It is characterized by the following.

The movable intermediate thread guide is preferably made of an eyelet, and it is likewise possible to constitute it with a rod. If the movable intermediate thread guide consists of eyelets, it is moved to a first position aligned with the two fixed thread guides and a second position offset with respect to the two fixed thread guides. It may be located at the position.

In such a device, the intermediate yarn guide controlled by the actuator is located at the first position where the intermediate yarn guide is not engaged with the weft during the supply of the weft, while the intermediate yarn guide is cut at the time of the yarn cutting after the supply of the weft is completed. 2 and deflects the weft to follow a curved path, whereby the frictional force generated on the weft greatly attenuates the oscillation and vibration of the weft caused by the cutting operation.

Thus, the objective is to release the weft (and thereby shorten the insertion time) and to re-route and friction the weft (and thereby dampen the oscillations and vibrations of the weft in special operating conditions of the loom. This can be achieved without compromising in terms of) and by properly operating the length measuring weft supply device.

[0020]

[Embodiment of the invention]

 Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings and embodiments.

FIG. 2 is a diagram showing an attenuating device based on the present invention provided at the end of the discharge port of the length measuring weft supply device. In this case, the type described in the introduction of this specification is used. A second yarn guide 4 is disposed near the yarn guide 3 fixed to the body of the length measuring weft supply device 1 of the first embodiment, and the second yarn guide 4 is also provided with the first yarn. It is fixed to the weft supply device 1 at a short distance from the guide.

A third thread guide 5 (eyelet-shaped or simply rod-shaped) is provided between the two thread guides 3 and 4 and is fixed to a movable part of an actuator 6. The actuator 6 comprises: a first position A A at which the intermediate thread guide 5 is aligned with the two thread guides 3 and 4; and a second position A A which is not aligned with the two thread guides 3, 4. And position BB.

The actuator 6 that operates electromechanically or electropneumatically is connected to an electric control circuit of the weft supply device 1, and the electric control circuit is a loom to which the weft supply device 1 is applied. According to the operation of, the actuator is operated accurately.

As is clear from FIG. 2, when the actuator 6 arranges the yarn guide 5 at the alignment position AA, the weft yarn f is not subjected to frictional force and path change.

On the other hand, when the intermediate guide 5 is arranged at the offset position BB by the actuator 6, the weft f is diverted so as to follow the bent path PS between the two yarn guides 3 and 4.

Since the actuator 6 is connected to the control circuit of the weft supply device 1, here, the position of the yarn guide 5 is limited only in the cutting process in which the weft is cut by the cutting device of the loom. BB.

In other words, the actuator 6 arranges the yarn guide 5 at the position AA during the insertion of the weft, moves the yarn guide 5 to the position BB after the insertion (during cutting), and then moves the yarn guide 5 to the position BB. Before starting insertion of the thread, the thread guide is moved to the position AA.

In such an apparatus, when the yarn guide 5 controlled by the actuator 6 is disposed at the position BB to deflect the yarn f and follow the bent path PS, the frictional force generated on the yarn f is reduced. The oscillations and vibrations caused by the cutting operation are greatly attenuated, thereby stopping the thread passing under the magnet pins.

Thus, the objective is to release the weft (and thereby shorten the insertion time) and to reroute and friction the weft (and thereby dampen the oscillations and vibrations of the weft in the special operating conditions of the loom. This can be achieved without compromising in terms of) and by properly operating the length measuring weft supply device.

FIG. 2 shows, of course, only the structural solution provided by one embodiment, wherein the movable thread guide 5 is not only an eyelet (as shown), but also a mere rod or It can also be composed of other elements of a shape that can deflect the weft and create friction there.

The same effect as described above is obtained by a device controlled in the same manner as described above, wherein instead of deflecting the weft, oscillation and vibration of the weft caused by cutting are attenuated. It can also be obtained by a device which provides a suitable slight braking action on the weft yarn as in the case of the device described above.

[Brief description of the drawings]

FIG. 1 is a diagram showing a weft insertion process of a jet loom.

FIG. 2 is provided at an end of a discharge port of a length measuring weft supply device;
FIG. 4 is a diagram showing a damping device based on the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Weft supply device 3, 4 Fixed first and second yarn guides 5 Movable third yarn guide 6 Actuator f Weft AA alignment position BB offset position PS Curved path

Claims (4)

[Utility model registration claims] 1. An attenuating device for greatly attenuating, at a discharge port of a weft supply device, oscillation and vibration of a weft supplied to the loom from the weft supply device, particularly when the loom is cut. A second thread guide fixed to the downstream side of the first thread guide parallel to it and cooperating with a normal first thread guide fixed to the discharge port of the device, and an intermediate position between them A first position in which the intermediate yarn guide does not engage with a weft in a path between the first and second two yarn guides, and the intermediate yarn guide does not grip the weft in the path. Oscillating and oscillating vibrations of the weft, which are movable between a first position and a second position which engages with the weft to deflect the weft from its path and follow a bent path between the first and second guides. In the damping device, the weft An actuator that operates based on the operation of the loom by an electric circuit of the yarn supply device and controls the position of the intermediate yarn guide, wherein the actuator does not engage the intermediate yarn guide with the weft while the weft is being supplied. In the air-type loom, the intermediate yarn guide is positioned at the second position where the intermediate yarn guide is deflected without grasping the weft when the yarn is cut after the supply of the weft is completed. A device for damping the oscillation and vibration of the weft of the weft supply device. 2. The apparatus according to claim 1, wherein said movable intermediate thread guide comprises an eyelet. 3. The apparatus according to claim 1, wherein said movable intermediate thread guide comprises a bar. 4. The eyelet as the movable intermediate thread guide is aligned with the two fixed thread guides in the first position and the two fixed thread guides in the second position. Device according to claim 2, characterized in that it is offset with respect to.