JPH10212642A - Weft gripping apparatus for water jet type weaving machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a timing for gripping an inserted weft most suitable and to optimize and uniform the tension of the weft during beating, by installing a weft gripping means, a yarn sensor, a flying speed calculating means, a gripping timing calculating means and a driving means. SOLUTION: In length measurement, a weft 12 is wound in fixed length required for inserting for once on the outer peripheral face of a drum and stored by rotating a yarn guide of a length measuring storage apparatus 16 in the state of the weft 12 being prevented by a holding pin 22 of the length measuring apparatus 16 from unreeling from a drum 20. In weft inserting, the weft 12 is jetted together with a fluid from a weft inserting nozzle 18 in the state of being unwound from the drum 20 by the release of the holding point 22 and inserted into an opening of warps 24. When the tip of the weft is reached to the opposite side of yarn supply, the tip of the weft is gripped by a gripping mechanism 30, brought back by a returning mechanism 28 and the weft is provided with tension.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for gripping a weft of a fluid jet loom.

[0002]

2. Description of the Related Art In a jet loom in which weft is inserted by a fluid ejected from a nozzle, that is, a fluid jet loom, the weft yarn is stored in a length measuring storage device with its leading end passed through a weft insertion nozzle. . At the time of weft insertion, the weft yarn is unwound from the locking pin of the length measuring and storing device, and is inserted into the warp opening by the fluid ejected from the weft insertion nozzle. When the weft insertion is completed, the injection of the weft insertion fluid is stopped, and the conveying force of the injected fluid to the weft disappears.

[0003] In such a fluid jet loom, the weft inserted into the weft is locked at the yarn feeding side at the end of the weft insertion. Have a tendency. Such loosening is caused by the fact that the portion on the leading end side (opposite to the yarn supply side) of the weft is in an unrestricted state. When the weft yarns relax, quality defects occur in the woven fabric.

[0004] In this type of fluid jet loom, at the end of weft insertion, the leading end of the inserted weft is grasped to prevent the weft from loosening. Also in such a loom, controlling the timing of weft gripping is very important for improving the quality of the woven fabric. That is, in view of the quality of the woven fabric, it is desired that the tension of the weft to be woven is uniform, and the gripping timing of the weft is set at the time when the weft is fully stretched in order to make the tension of the weft uniform. It is considered the best.

However, in general, the timing of arrival of the inserted weft on the non-supply side occurs every time the weft is inserted. Therefore, if the gripping timing is set to be constant, the weft at the time of gripping is set. There is a possibility that a poor texture or the like may occur, and that the weft may be gripped in a loose state, which may cause a loose weft or a loose ear of the woven fabric.

[0006] As one of the weft holding devices of the above-mentioned fluid jet loom, there is an apparatus described in Japanese Patent Application Laid-Open No. 3-241038. This device detects the passage of the leading end of the weft by a sensor provided on the non-supply side (the weft arrival side),
After a lapse of a predetermined time from the detection, the operation device of the weft gripper is driven.

However, in general, the flight state of a weft inserted weft, particularly the flight speed, changes due to a change in the state of the weft due to a change in unwinding resistance of the weft from the yarn supplying body.
A device that operates the gripper at a fixed timing after the detection of the weft as in the above-described conventional technology cannot cope with a change in the flight speed of the weft. As a result, in the above-mentioned prior art, the weft tension at the time of beating changes with a change in the flight speed of the weft, and the tension is not uniform over the entire woven fabric to be woven, resulting in a deterioration in quality.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to optimize the timing of gripping a weft inserted weft and to optimize and uniform the tension of the weft during beating.

[0009]

A weft holding device according to the present invention comprises a holding means for holding an end of a weft on a side opposite to a yarn feeding side, and an unwinding device provided facing a passage of the weft to detect the presence or absence of a weft. A yarn sensor such as a sensor, a flight speed calculation unit that receives a detection signal from the yarn sensor and calculates a flight speed of the weft;
The gripping timing calculating means calculates the timing of the maximum elongation of the weft based on the calculated flight speed and the measured length of the weft, and a driving means for driving the weft gripping means at the calculated timing.

The weft flight speed can be calculated, for example, from the signal from the unwinding sensor (yarn sensor) and the weft length per one turn of the weft to the drum of the length measuring and storing device.
Also, the length measurement amount of the weft can be the distance from the weft launch position to the maximum extension point of the weft, that is, the maximum extension length of the weft. The timing of weft grasping can be obtained from the flight speed of the weft and the measured length of the weft.

According to the present invention, the timing at which the weft elongates most is calculated from the flight speed of the weft and the length measurement amount,
Since the weft holding means is driven at the calculated timing,
The weft can be gripped when it is most stretched, and beating can be performed in that state.As a result, the timing for gripping the weft is optimized, and the tension of the weft during beating is optimized and uniform. Become.

In a preferred embodiment, the means for applying tension to the weft is disposed on the weft supply side. In this case, the tension applying unit is driven by another driving unit different from the driving unit for the weft holding unit at a predetermined timing calculated based on the detection signal of the yarn sensor.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a fluid jet loom 10 is an air jet loom. Weft 12
Extends from the yarn supplying body 14 and is measured and stored in a drum type length measuring and storing device 16 by a length necessary for one weft insertion. The leading end of the weft yarn 12 is passed through a main nozzle, that is, a weft insertion nozzle 18.

The length measuring and storing device 16 winds a weft 12 having a length necessary for one weft insertion around a length measuring and storing drum 20 and locks the weft with a locking pin 22 operated by an electromagnetic solenoid. It is locked by. The length measuring storage device 16 unwinds the locking of the weft 12 by the locking pin 22 at the time of weft insertion.

The nozzle 18 is connected to a compressed air supply. Air from the compressed air supply is supplied to the nozzle 18 via a valve mechanism. Thereby, the weft 12 is inserted into the opening of the warp 24. The weft insertion nozzle 18 is fixed to a sley (not shown) in the illustrated example, and thus is moved together with the reed 26 to the front side of the weaving during the beating process.

Between the length measuring and storing device 16 and the weft insertion nozzle 18, a retraction device 28 for retracting the inserted weft is arranged. On the other hand, a gripping mechanism 30 that grips the leading end of the inserted weft is disposed on the non-yarn supply side. The retraction mechanism 28 bends the weft 12 to pull back the weft portion inserted into the opening of the warp 24 to the yarn supply side. The gripping mechanism 30 grips the leading end of the weft in a state where the weft is bent.

In the illustrated example, a pull-back mechanism 28 is additionally provided so that a higher tension can be applied to the weft 12. However, the pullback mechanism 28 is not always necessary, and may not be provided, for example, when it is not necessary to increase the tension applied to the weft 12 so much.

At the time of length measurement, the yarn guide of the length measuring and storing device 16 is rotated by a predetermined number of times in a state where the weft is prevented from being unwound from the drum 20 by the locking pin 22 of the length measuring and storing device 16. By being rotated, the drum 20 is wound around the outer peripheral surface by a predetermined length necessary for one weft insertion and stored.

At the time of weft insertion, the weft 12 is unwound from the drum 20 by releasing the locking pin 22 and is ejected from the weft insertion nozzle 18 together with the weft insertion fluid, so that the weft 12 enters the opening of the warp 24. After the weft is inserted and the tip reaches the non-yarn supply side, the tip is gripped by the gripping mechanism 30 and pulled back by the pullback mechanism 28 to apply a predetermined tension.

A portion of the weft 12 inserted into the opening of the warp 24 (hereinafter referred to as "weft portion") is a reed 2.
It is moved toward the weaving together with 6, and finally struck before the weaving. At an appropriate time between the start of the insertion of the weft and the beating, the weft portion is moved by the gripping mechanism 30 to the weft 1.
2 is gripped and simultaneously or subsequently pulled back to the yarn supplying side by the pull-back mechanism 28.

Therefore, the weft portion is moved by the pullback mechanism 2
By pulling back by 8 and bending by the gripping mechanism 30, it is hit before weaving in a tensioned state.
After beating, the weft 12 is cut by a cutter (not shown), and the weft portion is cut off from the portion connected to the length measuring and storing device 16. As a result, the weft portion is pulled back by the pullback mechanism 28.
Is also released from.

In the illustrated example, the gripping mechanism 30 grips the weft 12 in a bent state outside the end of the woven fabric on the non-yarn feeding side. Accordingly, the gripping mechanism 30 exerts a force on the weft portion to draw the weft portion toward the non-supply side by this bending. As a result, the pullback mechanism 28 and the gripping mechanism 30
Applies a traction force to the weft portion from both sides thereof, and cooperates with each other to positively act on the weft portion.

When tension is applied to the weft portion by pulling the weft from both sides as described above, the operation of applying tension to the weft is shared by the pullback mechanism 28 and the gripping mechanism 30, so that an appropriate tension is applied to the weft. It can be applied uniformly over the entire effective length range of the part. Further, since the time required for applying the tension can be shortened and the time for one weft insertion can be shortened, the invention can be applied to a high-speed loom and the consumption of the weft insertion fluid can be reduced. Further, since the amount of traction per unit time increases, the present invention can be applied to a wide loom. The total effective length range is at least the range between the edges of the fabric and at least the range of the width of the finished fabric.

As a result, an appropriate tension is uniformly, quickly and reliably applied over the entire effective length range of the weft-inserted weft. Therefore, even in a high-speed loom or a wide-width loom, looseness or looseness of ears does not occur in the weft, and there is no possibility that the weft is woven into the woven fabric in a state where the weft has a difference in tension between the yarn supply side and the non-yarn supply side.

The timing of unwinding of the weft yarn 12 from the length measuring and storing device 16 by the locking pin 22 is controlled by a timing signal output from a timing signal generator 32 in synchronization with the rotation of the main shaft 34 of the loom. Therefore, the fluid jet loom 10 includes an encoder 36 that generates a pulse signal every time the main shaft 32 rotates by a predetermined angle. The timing signal generator 32, based on the output signal of the encoder 36,
Each time the rotation angle of the main shaft 32 reaches a predetermined value, a timing signal (unwinding signal) is generated.

The operation timing of the pull-back mechanism 28 and the gripping mechanism 30 is calculated based on the flight speed of the weft 12 and the length measurement amount. To calculate the weft flight speed, the fluid jet loom 10 uses the unwinding sensor 40 that detects the loop of the weft unwound from the drum 20 of the length measuring and storing device 16 as a yarn sensor.

The unwinding sensor, that is, the yarn sensor 40, is arranged facing the path of the loop of the weft unwound from the length measuring storage device 16, and detects the presence or absence of the weft unwound from the drum 22. Each time a weft is detected, a yarn detection signal indicating that fact is output to the amplifier circuit 42. Amplifier circuit 42
Amplifies the yarn detection signal of the yarn sensor 40 and supplies it to the traveling speed calculator 44.

The flight speed calculator 44 determines that a yarn detection signal is generated each time one weft of the weft is unwound from the drum 20 and that the length of the weft wound around the drum 20 is equal to one turn. Is known, the weft traveling speed is calculated from the yarn detection signal supplied from the amplifier circuit 42 and the weft length per one turn of the weft to the drum 20.

The weft running speed V _L is shown by the solid line 4 in FIG.
6 and the two-dot chain line 48, the time interval between the two yarn detection signals is ΔT,
Assuming that the length per one winding of the weft to 0 is ΔL, it can be obtained by calculating the following equation (1).

V _L = ΔL / ΔT (1)

Instead of the above, the weft flight speed V _L is detected by a weft sensor provided on the opposite side of the weft supply side or in the warp area and facing the weft flight path to detect the passage of the leading end of the weft. It may be calculated from the signal and the flight length of the weft to the position of the weft sensor.

In FIG. 2, the vertical axis is the distance L from the weft arrival position, that is, the launching position, and the horizontal axis is the time, that is, the elapsed time T from the launching start.
Indicates a curve for a low flight speed, a two-dot chain line 48 indicates a curve for a high flight speed, and Ln indicates a maximum elongation point of the weft. La, Lb, Lc, and Ld respectively indicate the timing at which a yarn detection signal is output from the yarn sensor 40 in relation to the arrival position of the weft.

The time interval ΔT between the two yarn detection signals can be calculated by the flight speed calculator 44 using the output signal of the amplifier circuit 32. Further, the length ΔL per one turn of the weft to the drum 20 can be set in the flight speed calculator 44 in advance because the length itself is known. Running weft velocity V _L calculated in Hihashi velocity calculator 44 is output to the gripping start timing calculator 46.

The grip timing calculator 46 determines the timing at which the pullback mechanism 28 and the grip mechanism 30 are operated.
It is calculated from the measured length L of the weft yarn 12 and the timing signal output from the timing signal generator 32.

As shown in FIG. 2, the length measurement amount L of the weft 12 can be the distance from the weft launch position to the maximum extension point of the weft, that is, the maximum extension length Ln of the weft. In addition, since the length measurement amount L of the weft 12 is itself known, it can be set in the gripping timing calculator 46 in advance. The timing signal is a signal that specifies the timing of the calculation in the gripping timing calculator 46.

The timing T ₀ for operating the pull-back mechanism 28 and the gripping mechanism 30 can be obtained by calculating the following equation (2).

T ₀ = Ln / V _L = Ln · ΔT / ΔL (2)

The timing T ₀ calculated by the grip timing calculator 46 is supplied to a timing output unit 48. The timing output device 48 outputs the first drive signal to the first drive means 50 for the gripping mechanism 30 when the input timing T ₀ is reached, and at the same time or thereafter, pulls back the second drive signal. Output to the second drive means 52 for the mechanism 28.

The first driving means 50 drives the gripping mechanism 30 so as to grip the leading end side of the weft inserted weft portion. The second driving means 52 drives the pullback mechanism 28 so as to be drawn toward the rear end side (yarn supply side) of the weft-inserted weft portion. Grasping mechanism 30 and pullback mechanism 2
8 releases the weft portion until the beating is completed or at an appropriate time after the beating.

The operation start timing of the retraction mechanism 28 may be substantially the same as that of the gripping mechanism 30, or may be operated after the retraction mechanism 28 than the gripping mechanism 30. That is, the retraction mechanism 28 may start the retraction after the weft is caught by the gripping mechanism 30 on the non-supply side, or conversely, the retraction mechanism 2
8 may be operated before the gripping mechanism 30.

The first driving signal for gripping mechanism 30, the gripping mechanism from the timing T ₀ of elongation of the weft is up to 30
Can be generated on the basis of the elapsed time from the start of launching or an appropriate time thereafter, as long as the operation starts and the weft is gripped.

At the end of the operation of the pull-back mechanism 28 and the gripping mechanism 30, the timing relating to the rotation angle of the main shaft of the loom is set in accordance with the weft insertion period and beating timing set according to the type of yarn to be used and the weaving pattern. It is set in advance. The amount of weft pulled back by the pullback mechanism 28 and the amount of weft bending by the gripping mechanism 30 are also set in advance according to the type of yarn to be used and the weaving pattern. Any of these values can be determined from preliminary test weaving, experience, and the like.

As described above, when the weft holding mechanism 30 is driven at the timing when the weft elongates most at the timing calculated from the flight speed of the weft and the length measurement amount, the weft 12
Is gripped when stretched most, and is beaten in that state. As a result, the timing for gripping the weft 12 is optimized and the tension of the weft during beating is optimized and uniform.

In a multicolor loom that selectively uses a plurality of wefts, the same number of measuring and storing devices 1 as the number of wefts to be used are used.
6. A retraction mechanism 28 and a weft insertion nozzle 18 are provided. However, the gripping mechanism 30 is commonly used. In this case, it is preferable to change the amount of bending by the gripping mechanism 30 according to the type of yarn and the like.

One embodiment of the gripping mechanism 30 is shown in FIGS.
Shown in The gripping mechanism 30 is held by a lead holder 60 on which the reed 26 is supported. In addition to the reed 26 and the gripping mechanism 30, the lead holder 60 holds a weft detecting device 62 that detects the leading end of the weft inserted into the opening of the warp. The weft detecting device 62 is driven by a screw member 68 such as a bolt so that the detecting portion is located between the fabric end on the non-yarn feeding side, that is, the woven fabric end 64 and the discarded ear portion 66.
It is attached to 0.

The lower end of the gripping mechanism 30 is connected to the lead holder 6.
And a pair of first bending means or arms 74 spaced in the flight direction of the weft 12, that is, the weft insertion direction.
And a second bending means or arm 76 disposed above both first arms 74, and a drive source 78 for rotating the second arm 76 angularly within a predetermined range.

In the illustrated example, the bracket 72 is
0, and one or more screw members 82 such as bolts penetrating through the lead gripper and screwed to the lead holder 60.
It is immovably assembled so as to extend upward.
However, the bracket 72 may be directly attached to the lead holder 60 by one or more screw members, or may be attached to a frame of a loom via a bracket or the like.

The bracket 72 has, at the top, a hole that penetrates the weft 12 in the flight direction, and a notch that connects the hole to the top. The drive source 78 is immovably supported in the hole. I have. The drive source 78 is a pulse motor, and is inserted into a hole of the bracket 72 so that its rotation shaft, that is, the output shaft 84 extends in the weft insertion direction, and is moved to the bracket 72 by one or more screw members 86 such as bolts. It is improperly assembled.

The first arm 74 includes two first arms 74.
A pair of collars 88 disposed therebetween, and both first arms 7
4 and a pair of screw members 90 such as bolts which are screwed into the screw holes of the bracket 72 through the collar 88 are immovably attached to the bracket 72 at two lower positions. Both first arms 74 are formed by plate members and extend in parallel with each other. Each first
The arm 74 has a first contact portion 92 at the upper portion extending below the flight path of the weft 12 in a direction intersecting the weft insertion direction. The first contact portions 92 extend in parallel with each other with an interval in the weft insertion direction.

The second arm 76 is formed by a plate member. The second arm 76 is connected to the output shaft 84 of the drive source 78 so as to extend in parallel with the first arms 74 in a direction intersecting the weft insertion direction between the two first arms 74 in a plan view. It is immovably assembled. Second arm 7
No. 6 has a second contact portion 94 at the tip end thereof extending above the flight path of the weft 12 in a direction intersecting the weft insertion direction.

The second arm 76 is normally maintained at a position where the second contact portion 94 is above the flight path of the weft 12 as shown in FIG.

At the time of weft insertion, the weft 12 is
4 is displaced as shown in FIG. 4, the weft 12 is inserted into the warp opening so that the leading end of the weft 12 reaches between the first contact portion 92 and the second contact portion 94.

When the weft insertion is completed, the leading end of the weft 12 is
When the second contact portion 94 reaches between the first contact portion 92 and the second contact portion 94, the second contact portion 94 traverses the flight path of the weft 12 and reaches between the first contact portions 92. The arm 76 is rotated clockwise (in the direction indicated by the arrow 96) in FIG. As a result, the leading end of the weft 12 is grasped or caught by the first contact portion 92 and the second contact portion 94, and is bent in a substantially U shape by the contact portions 92 and 94.

The bending of the weft 12 by the gripping mechanism 30 acts on the weft 12 as a force for pulling the weft 12 toward the gripping mechanism 30. As described above, the weft 12 is gripped and bent by the pullback mechanism 28 on the weft insertion side, that is, on the yarn supply side, so that the pulling force and the tension to be applied to the weft 12 together with the pullback force by the pullback mechanism 28. Become.

Next, the weft 12 is moved toward the weaving side along with the forward movement of the reed 26, and the weft portion of the weft 12 inserted into the opening of the warp is hit by the reed 26 before weaving. The yarn is cut from the yarn on the yarn supply side by a cutter (not shown). Immediately before the beating, at the same time as the beating, or at an appropriate time after the beating, the gripping mechanism 30 reverses the driving source 78 by a predetermined angle and causes the second contact portion 9 to rotate.
The weft 12 is released by returning the weft 4 above the flight path of the weft 12.

As described above, the second arm is connected to the pair of first arms.
Instead of being placed above the arm of this, it may be placed in reverse. That is, the pair of first arms may be arranged above the weft flight path, and the second arm may be arranged below the weft flight path. In this case, the rotation direction of the second arm is opposite to the direction of the arrow 96 in FIG.
Also, instead of displacing the second arm with respect to the first arm, the first arm may be displaced with respect to the second arm, or both the first and second arms may be displaced. Is also good.

One embodiment of the pullback mechanism 28 is shown in FIGS. The pullback mechanism 28 includes a drive source 100 capable of controlling the angular rotation position of a rotor like a pulse motor.
And a fixed arm 1 made of a linear member bent in a U-shape
02 and a movable arm 104 that is displaced by the drive source 100 to bend the weft 12 in cooperation with the fixed arm 102.

The drive source 100 has an elongated plate member attached to an L-shaped curved bracket 106 by a plurality of screw members. The output shaft of the drive source 100, that is, the rotation shaft 108, penetrates the bracket 106 rotatably. The fixed arm 102 is fixed to a plate-shaped mounting member 110, and the movable arm 104 is fixed to a rotating shaft 108 via a mounting member 112.

The mounting member 112 is mounted on the rotating shaft 108 such that the movable arm 104 extends in a direction perpendicular to the rotating axis of the driving source 100 and swings across a line parallel to the rotating axis of the driving source 100. Drive source 1
00 provides an angular reciprocating rotational movement about the rotational axis of the drive source 100. The movable arm 104 is formed of a linear member bent in a U-shape, and is attached to the mounting member 112 such that two portions of the linear member are spaced from each other in the direction of the rotation axis of the drive source 100.

In the bracket 106, the rotation axis of the drive source 100 is in the flight direction of the weft 12, and the movable arm 104 swings across the flight path of the weft 12,
Are indirectly assembled to the frame of the loom with a plurality of screw members or the like so that the two portions of the linear member are spaced apart in the flight direction of the weft 12. The attachment member 110 is mounted on a frame of a loom via a bracket or the like so that the fixed arm 102 extends between the two members of the movable arm 104 and the weft 12 travels between the two members of the fixed arm 102. Indirectly fixed.

When the power of the loom is not turned on, the movable arm 104 is attached to the mounting member 11 by its own weight.
The pull-back mechanism 28 is rotated by its own weight so as to extend downward from the position 2 in accordance with the mounting position of the retraction mechanism 28 (in the illustrated example, the position indicated by the symbol a). When the power of the loom is turned on, the driving source 100 moves the movable arm 104 to the mounting member 1.
After the normal rotation to the initial position (the position indicated by the symbol b) which comes into contact with 10, the rotation is reversed by a certain angle α. This allows
The movable arm 104 is rotatably moved to a reference position (a position indicated by reference numeral c) where the movable arm is above the weft 12 and is maintained at the reference position.

While the power of the loom is turned on, the driving source 1
00 is reversed by the angle θ each time a reverse rotation command is issued, and is rotated forward by the same angle θ each time a forward rotation command is issued. As a result, the movable arm 104 is moved from the reference position (the position indicated by the symbol c) to the fixed arm 1.
It is moved to an operating position (position indicated by reference numeral d) for bending the weft yarn 12 in cooperation with 02 and vice versa. The weft 12 is
When the movable arm 104 is rotated from the reference position to the actuated position, the arms 102, 104 cooperate to bend back into a U-shape and thereby receive tension.

As the driving sources 86 and 100, a rotary actuator such as a pulse motor, a servomotor, and a rotary solenoid can be used.

If a pulse motor is used as a drive source, the number of pulses supplied to the pulse motor can be changed to
Because the stroke of the arm changes, the adjustment of the stroke of the arm is easy, the adjustment of the gripping force of the weft is easy, and it can be applied to weak yarns. No delicate parts or multi-core cables are required. There are advantages such as being less likely to break down even when attached to a movable part.

Instead of the gripping mechanism 30 shown in FIGS. 3 and 4, the gripping means may be a pair of adjacent reed wings and a pair of reeds, as in a weft end catching device described in Japanese Patent Publication No. 43903/1990. It is also possible to use one in which the weft is gripped in a bent state by the catching plate that enters and exits between the wings. Further, instead of the above-described device that holds the weft in a bent state, a device having only a holding function, such as a clamper including a pair of holding bodies, may be used.

Instead of rotating the arm as in the gripping mechanism 30, the arm may be moved linearly. Also,
Instead of using a rotary drive source as the arm driving means, a reciprocating drive source in which the mover moves linearly like a linear motor may be used. Furthermore, instead of assembling the gripping mechanism to the lead holder with a bracket,
It may be assembled to the lead holder or other parts of the loom such as the frame by other means.

Instead of the gripping mechanism 30 shown in FIGS. 3 and 4, a pullback mechanism 28 shown in FIGS. 5 and 6 may be used as a gripping mechanism. Similarly, instead of the retraction mechanism 28 shown in FIGS. 5 and 6, the gripping mechanism 3 shown in FIGS.
0 may be used as the pullback mechanism.

The present invention is not limited to the above embodiment. For example, a suction device that sucks the leading end of the weft until the gripping mechanism 30 completes gripping the weft leading end may be arranged downstream of the gripping mechanism 30.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a fluid jet loom equipped with a weft gripping mechanism of the present invention.

FIG. 2 is a diagram for explaining a timing of gripping a weft in the loom of FIG. 1;

FIG. 3 is a front view showing an embodiment of a traction device and a gripping mechanism in the loom of FIG. 1;

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a perspective view showing one embodiment of a pullback mechanism in the loom of FIG. 1;

FIG. 6 is a left side view of the pullback mechanism of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 10 loom 12 weft 14 yarn feeder 16 measuring and storing device 18 weft insertion nozzle 20 measuring and storing drum 22 locking pin 24 warp 26 reed 28 retraction mechanism 30 gripping mechanism 40 unwinding sensor (yarn sensor)

Claims (1)

[Claims] 1. A gripping means for gripping an end of a weft on a side opposite to a yarn feeding side, a yarn sensor provided facing a passage of the weft to detect the presence or absence of a weft, and a detection signal based on a signal from the yarn sensor. Receiving speed calculating means for calculating the running speed of the weft upon receipt, gripping timing calculating means for calculating the timing of the maximum elongation of the weft based on the calculated running speed and the measured length of the weft, And a driving means for driving the weft holding means at the right timing.