JPS63774Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for relieving the tension of the weft yarn at the end of weft insertion.

BACKGROUND ART Conventionally, in a fluid injection type loom, it is necessary to separate the weft yarns for one weft insertion prior to the end of weft insertion, and various devices have been proposed and put into practical use for this purpose.

What is shown in Figures 1 to 3 is JP-A-57-
This is an example of the device described in Publication No. 29640.

However, in the above device, the weft wound and stored on the weft storage drum is inserted at the weft insertion time, and at the end of the weft insertion, the weft is locked in the locking body. Since the weft insertion is carried out at different times, the impact causes abnormal tension in the weft yarn at the end of weft insertion, resulting in a problem of weft yarn breakage.

There is also a weft storage device that stores the measured weft by placing it on an air flow, but even with this method,
Changing from free running to length measurement flight, and finishing weft insertion from length measurement flight, that is, with the weft gripper,
When the weft yarns were gripped, abnormal tension was also generated in the weft yarns, resulting in the above-mentioned problems.

For example, a device described in Japanese Utility Model Application Laid-open No. 56-60789 is known as a device for solving such problems.

This can be done by disposing a picktensor that holds the weft near the thread guiding hole of the weft insertion nozzle, and using this picktensor to hold the weft under a constant slight pressure at all times, or when inserting the weft. By not pinching the inserted weft yarn, it is possible to prevent yarn trouble due to the reaction energy of the spring back generated when cutting the inserted weft yarn.

However, with the above-mentioned devices, especially those of the type in which the weft is held under constant slight pressure by the pick tensor, it is possible to prevent abnormal tension of the weft at the end of weft insertion, but the weft cannot be held at all times. Since the weft is held under a slight pressure, the flying speed of the weft yarn, that is, the weft insertion speed is reduced, which is an obstacle to increasing the speed of the loom, which is inconvenient.

The present invention was developed in view of these problems with conventional devices, and aims to reduce the abnormal tension that occurs by gradually providing flying resistance in the latter half of the weft insertion period. .

An example in which the present invention is implemented in an air injection loom equipped with a drum type weft storage device will be described below with reference to the drawings.

In addition, the weft storage device is disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 57-29640.
Since it is described in the above publication, a detailed explanation will be omitted and only the parts necessary for explaining the present invention will be explained.

In the figure, 1 is a frame of a loom, and 2 is an air injection nozzle for weft insertion held in a nozzle holder 3 that stands up on the frame 1. Reference numeral 4 denotes a bracket which is fixed to the outer surface of the frame 1 with bolts 5 and arranged horizontally, and 6 is a bracket whose upper end is formed as a bearing portion 6a, which is fixed to the bracket 4 with bolts 7. A rotary shaft 8 is rotatably supported by the bearing portion 6a, and a toothed pulley 9 is fixed to the rear end of the rotary shaft 8 and a toothed pulley 9 is connected to a drive pulley (not shown) of the loom. A belt 10 is wrapped around the belt 10 so that the rotating shaft 8 is rotated in relation to the loom.

A holder 11 is supported at the front end of the rotating shaft 8 so as to be relatively rotatable. A drum 13 is fixed to the holder 11 with bolts 12, and the drum 13 is held stationary by a magnet or weight (not shown). I try to keep it at that. On the circumferential surface of the drum 13, there is formed a tapered part 13a whose outer diameter gradually decreases from the rear end side to the front end side, and a straight part 13b continuous to the minimum diameter part with the same diameter.

Further, a thread guiding hole 14 that opens to the rear end surface is formed in the axis of the rotating shaft 8, and a winding guide 15 whose tip end faces the tapered part 13a of the drum 13 is fixed near the tip of the rotating shaft 8. A guide hole 16 is provided at the tip of this winding guide 15. 17 is an air injection nozzle for drawing the weft;
8 is a bracket of the same nozzle and is fixed to the bracket 6.

The weft W pulled out from the yarn supplying body (not shown) passes through the nozzle 17 and the yarn guide hole 14, and then passes through the winding guide 16.
The weft is wound around the drum 13 by the first and second locking bodies 21 and 22 and stored prior to weft insertion. At this time, for example, the length of the weft wound around the drum 13 three times is sufficient for one weft insertion. The locking bodies 21 and 22 are configured to enter and exit holes 23 and 24 formed in the drum 13 in association with the loom by a control mechanism 19 such as a cam.

Reference numeral 25 denotes a guide provided at the tip of a bracket 26 fixed to the frame 1 with screws 27, and is aligned with the axis of the rotating shaft 8.

Reference numeral 28 denotes a guide provided on a U-shaped bracket 30 fixed to the frame 1 with bolts 29, and the weft W drawn out from the drum 13 is passed through the guide 25 and then also passed through the guide 28. and passed through the nozzle 2.

Reference numeral 31 is a rod that bends the weft yarn W between the guides 28 and 28 and provides flying resistance. A bracket 3 fixed to the frame 1 with a bolt 34 is attached to a cam 33 fixed to a rotating shaft 32 that rotates in synchronization with the loom.
A cam follower 38 provided at the tip of a cam lever 37 is fixed to one end of a rotating shaft 36 which is rotatably supported by a bearing portion of the rotating shaft 36, and a cam follower 38 provided at the tip of a cam lever 37 is in contact with the other end of the rotating shaft 36. is fixed,
The cam 33 is designed to oscillate depending on the height of the cam ridge. These rods 31, cams 33, cam levers 37, and cam followers 38 form a weft bending means 40.
Configure.

Next, the action will be explained.

The weft W stored in the drum 13 prior to weft insertion is inserted into a warp opening (not shown) by the nozzle 2 at the same time as the locking body 22 leaves the hole 24 of the drum 13, and the weft W is stored in the locking body 21. collide and weft insertion is completed.

The cam 33 is rotating to the left in FIG. 3, and in the latter half of the weft insertion period, the cam follower 38 starts to come into contact with the crest, and the rod 31 cuts the axis of the guide 28 horizontally, thereby cutting the weft. W is bent between the guides 28 to give flying resistance to the weft W. This resistance is gradually increased, that is, the amount of bending is gradually increased, and the resistance is set to be maximum before the weft insertion is completed. The weft is then returned to the position shown by the solid line in FIG. 3 before the next weft insertion. The timing is shown in FIG.

According to the present invention, by gradually applying flying resistance to the weft in the latter half of weft insertion, the weft tension increases rapidly due to the collision between the locking body 21 and the weft W at the end of flying. This makes it possible to reduce the difference in weft tension just before the end of flight, prevent excessive tension, and prevent troubles such as weft breakage.

In the above explanation, the case where a drum type was used as the weft storage device was described, but as mentioned above, it goes without saying that it is also effective to use other weft storage devices. It can also be used in jet looms.

[Brief explanation of the drawing]

Fig. 1 is a front view of a fluid jet loom equipped with the weft tension relaxation device of the present invention, Fig. 2 is a plan view of Fig. 1,
Figure 3 is a front view of the weft tension relaxation device of the present invention;
The figure is an operation timing diagram. 1...Frame, 2...Weft insertion nozzle, 13
. . . Weft length measuring and storage device, 40 . . . Weft bending means.

Claims (1)

[Scope of utility model registration request] In a fluid jet loom equipped with a weft length measuring and storage device 13 that separates the wefts W corresponding to one weft insertion prior to the end of weft insertion, the weft length measurement and storage device 13 leads to the weft insertion nozzle 2. A weft bending means 40 for bending the weft by contacting the weft is provided in the middle of the weft path, and the fluid jet is set to bend the weft in the latter half of the weft insertion period and gradually provide resistance to the weft flying. Weft tension relaxation device for type looms.