Weft handling apparatus in a jet loom

Abstract

 The apparatus is preventing a broken weft piece (Y₁), which results from a weft break taking place adjacently to the outlet of the weft winding tube (1b) of the weft measuring and storage device (1) of winding type, from being inserted into a warp shed (W), and subsequently withdrawing the weft portion present at the cloth fell (W₁) of woven fabric by pulling its succeeding weft portion prevented from being inserted.
The winding amount of reserve weft on the weft winding surface (1a) of the weft measuring and storage device (1) is detected by the reserve weft sensor (8). The information from such detection is transmitted to the computer control (C), which activates the blow nozzle (15) to prevent weft insertion in response to "no reserve weft" signal from the reserve weft sensor (8).

Description

[0001] The present invention relates to a weft handling apparatus in a jet loom wherein a weft unwound from a weft supply cheese is measured by winding and stored temporarily as reserve weft on a weft measuring and storage device type and such reserve weft is then inserted into a warp shed by air jet injected from a main weft inserting nozzle.

[0002] Publication of Unexamined Japanese Patent Application No. 63-303148 (1988) discloses an apparatus for disposing of a weft piece resulting from a weft break which has taken place in between a weft supply cheese and a weft measuring and storage device of winding type of a jet loom. This apparatus has a weft break sensor disposed in a weft passage between the cheese and the weft measuring and storage device for detecting a weft break, if any occurs therebetween, and it is so arranged that insertion of a broken weft piece into a warp shed is prevented when the weft sensor generates a signal in response to the weft break. If a weft break occurs on the side upstream of a weft measuring and storage device in a jet loom, it will be properly detected as a long pick by a weft sensor located at the terminating end of the weft inserting passage, but the trailing end portion of the broken weft piece will enter into a warp shed. Though normal weft insertion may be accomplished even in the event of a weft break, in a jet loom of the type which uses breezing air to maintain the leading end of an inserted weft in a favorably extended position, the trailing end portion of a broke weft piece is also blown into a warp shed, which makes it very troublesome to remove afterward the weft piece from the cloth fell of a woven fabric. The above-cited prior art apparatus, which is intended to solve the above troublesomeness, facilitates the removal of the broken weft piece from the cloth fell by preventing part of the weft from being inserted into the warp shed.

[0003] However, in a jet loom having a weft measuring and storage device adapted to measure a predetermined length of weft by rotating its weft winding tube around a weft winding surface thereby to form and temporarily store windings of reserve weft round the surface, the weft break tends to occur most frequently adjacent to the outlet of the winding tube. The above-cited prior art apparatus is unable to perform its function of preventing the weft insertion in the event of such a weft break that takes place adjacent to the outlet of the winding tube of the weft measuring and storage device.

[0004] Therefore, an object of the present invention is to provide a weft handling apparatus which can make possible smooth disposal of a broken weft piece in view of typical situation where a weft break occurs most freguently in a jet loom.

[0005] In the apparatus according to the present invention, there is provided reserve weft detecting means adjacently to the weft winding surface of the weft measuring and storage device, weft insertion preventing means, and control means for activating the weft insertion preventing means in response to a signal from the reserve weft detecting means then detecting no reserve weft on the weft winding surface.

[0006] If a weft break occurs adjacently to the outlet of the weft winding tube of the weft measuring and storage device, the broken weft piece on the winding surface is released immediately and, accordingly, the reserve weft detecting means detects the absence of reserve weft on the weft winding surface. In response to a signal from the reserve weft detecting means representative of such absence, the control means activates the weft insertion preventing means. Therefore, a situation where the entire broken weft piece is inserted into a warp shed can be prevented

[0007] The following will describe an embodiment of the apparatus according to the present invention while referring to FIGS. 1 through 7.

FIG. 1 is a schematic diagram showing the combination of weft insertion preventing means the control circuit;

FIG. 2 is a schematic diagram similar to that of FIG.1, but showing a condition where a weft break has occurred;

FIG. 3 is a schematic diagram similar to that of FIG.1, but showing a condition where the weft is nipped by the paired rollers;

FIG. 4 is a schematic diagram similar to that of FIG.1, but showing a condition where a faulty weft is being withdrawn;

FIG. 5 is first part of flow chart showing the program for disposing of a broken weft piece;

FIG. 6 is second part of the flow chart showing theprogram; and

FIG. 7 is third part of the flow chart showing the program.

[0008] Reference numeral 1 designates a weft measuring and storage device of winding type adapted for use in a jet loom. This device is of a known structure having a weft winding surface 1a and a weft winding tube 1b. A weft Y fed from a cheese 2 is passed through the weft winding tube 1b rotatable around the weft winding surface 1a and a predetermined length of weft is wound round the weft winding surface 1a to be temporarily stored thereround as the windings of reserve weft Y₁. The weft winding tube 1b is driven to rotate by a motor 4 which is provided independently from a main motor 3 for driving the loom.

[0009] Releasing of the windings of reserve weft Y₁ on the winding surface 1a is controlled by a stop pin 5a which is movable into and out of engagement with the winding surface 1a by operation of an electromagnetic solenoid 5. There is provided a photoelectric weft release sensor 6 of reflection type adjacently to the weft winding surface 1a. An output signal of the weft release sensor 6 representing that a reserve weft Y₁ has been released from the winding surface 1a is transmitted to a computer control C which, responding to such signal from the weft release sensor 6 and also to the information of current rotational angle of the loom detected by a rotary encoder 7, controls the on/off operation of the electromagnetic solenoid 5. Such on/off operation of the solenoid 5 causes the stop pin 5a to move into and away from engagement with the weft winding surface 1a for alternatively forming windings of a reserve weft Y1 and then releasing such reserve weft.

[0010] Adjacently to the weft winding surface 1a is arranged a reserve weft sensor 8 for detecting the winding amount of the reserve weft

on the weft winding surface 1a. The information of the winding amount is transmitted from the reserve weft sensor 8 to the computer control C. According to the information from the reserve weft sensor 8, the control C controls the operational speed of the weft winding motor 4 so that a reserve weft with a predetermined amount is wound at all times round the weft winding surface 1a.

[0011] The reserve weft Y₁ on the winding surface 1a is inserted into a warp shed by air jet injected from a main weft inserting nozzle 9. The nozzle 9 has connected thereto a tube 10 for supplying air under pressure and another tube 11 for supplying breezing air. Supply and stop of the air to the main weft inserting nozzle 9 through the tube 10 is controlled by a solenoid-operated valve

. The breezing air is supplied constantly to the nozzle 9 for maintaining the leading end of an inserted weft in a favorably extended position.

[0012] A pair of weft sensors 12, 13 is disposed at the terminating end of the weft inserting passage for detecting the leading end of an inserted weft Y. In response to signals from the weft sensors 12, 13, the computer control C commands the weaving loom either to continue or to interrupt its operation. That is, if weft insertion is done properly, the leading end of the inserted weft Y only reaches the weft sensor 12 to be detected thereby, but the weft sensor 13 is not reached by the inserted weft. Thus, all situations except the one where the leading end of the inserted weft is detected only by the weft sensor 12, are considered by the computer control C that a failure in weft insertion has occurred. Accordingly, the control C renders the solenoid for the valve

, a weft cutter 14 and the solenoid 5 for stop pin 5a inoperative and, simultaneously, causes the main drive motor 3 and the weft winding motor 4 to be stopped.

[0013] A blow nozzle 15 is disposed immediately below the main weft inserting nozzle 9 such that an air jet from the blow nozzle 15 intersects the air jet from the weft inserting nozzle 9. There is provided a weft introducing duct 16 having its inlet positioned in facing relation to the exit of the blow nozzle 15. The weft introducing duct 16 has its exit directed oppositely to the direction of weft insertion by the nozzle 9. An air guide 17 and its associated suction pipe 19 are located adjacently to the exit of the weft introducing duct 16 and a weft sensor 18 of photoelectric transmission type is mounted within the air guide 17. The suction pipe 19 is bent and its exit is directed toward a dust box (not shown). The suction pipe 19 has at its bent portion a blow nozzle 20 which produces air flow toward the dust box (not shown).

[0014] The main weft inserting nozzle 9, blow nozzle 15, weft introducing duct 16, air guide 17 and suction pipe 19 are all mounted on a slay of the weaving loom for swinging movement therewith. Behind the swinging area of these parts 9, 15, 16, 17, 19 are located a motor 21 and an air cylinder 22. A drive roller 23 is operatively connected to the motor 21 to be driven thereby and its associated follower roller 24 is mounted to the drive rod of the air cylinder 22 so that extending motion of the cylinder 22 causes the follower roller 24 to be brought into contact engagement with the drive roller 23. The blow nozzles 15, 20 are connected to air supply source (not shown) through solenoid-operated two-way valves V₂, V₃, respectively. The air cylinder 22 is connected to the air supply source (not shown) through a solenoid-operated three-way valve V₄. Like the motors 3, 4, the solenoid 5, the cutter 14 and the solenoid for the valve V₁, operation of the solenoids for the valves V₂ through V₄ and the motor 21 are controlled from commands by the computer control C. The computer control C is operable according to a program shown in FIGS. 5 through 7 for disposing of a weft piece in the event of occurrence of a weft break.

[0015] As mentioned earlier, a weft break between the cheese 2 and the main weft inserting nozzle 9 occurs most frequently at a position adjacent to the outlet of the weft winding tube 1b. In the event of such a weft break, the reserve weft Y₁ on the winding surface 1a is released therefrom immediately when the stop pin 5a is moved away from engagement with the winding surface. This abnormal release of the reserve weft Y₁ is detected by the reserve weft sensor 8, which then generates a "no weft" signal to the computer control C. In response to this signal, the control C generates commands to render the solenoid for the valve V₁ and the weft cutter 14 inoperative and, simultaneously, cause the solenoid for the valve V₂ to be energized for a predetermined period of time to activate the blow nozzle 15 for the same period of time. Air jet is issued from the blow nozzle 15 to divert part of the weft into the weft introducing duct 16, as shown in FIG. 2, thus preventing the entire weft from being inserted into a shed. The portion of the weft Y₁ blown into the duct 16 is moved past the region between the paired rollers 23, 24. As the weft reaches the air guide 17, it is detected by the weft sensor 18.

[0016] If no weft is detected by the weft sensor 18, the computer control C actuates an alarm device 26.

[0017] Substantially simultaneously with generation of the above command to energize the solenoid for the valve V₂ for the predetermined period of time, the control C provides commands to stop the motors 3, 4 and to make the solenoid 5 inoperative. Actuation of the blow nozzle 15 to divert the weft into the weft introducing duct 16 is completed before the loom is coasted to a complete stop at a position just before the beating-up position is reached. Thereafter, the motor 3 is rotated reverse at a slow rate for a predetermined amount so as to form a wide-open shed by upper and lower sheets of warp yarn T. Thus, the faulty weft Y₂ inserted halfway through the shed and beaten up to the cloth fell W₁ of a woven fabric W is freed from the fabric.

[0018] If the control C receives a "weft detected" signal from the weft sensor 18, the solenoids for valves V₃, V₄ are energized to activate the blow nozzle 20 and to extend the air cylinder 22, respectively. Air under pressure is blown from the blow nozzle 20 into the weft guide 19 and the roller 24 is moved into contact engagement with its associated roller 23 to nip therebetween the weft, as shown in FIG. 3. Subsequently, the motor 21 is started to drive the roller 23. The paired rollers 23, 24 pull the weft Y₁ while withdrawing the faulty weft Y₂ from the cloth fell W₁.

[0019] As the entire weft Y₂ moves past the air guide 17, the weft sensor 18 then responding to the absence of a weft transmits a signal to the control C, which in response to this signal causes the motor 21 to be stopped and the solenoids for valves V₃, V₄ to be deenergized.

[0020] As it is now apparent, if a weft break occurs adjacently to the outlet of the weft winding tube 1b, it can be ascertained immediately by the reserve weft sensor 8 adapted to detect the presence or absence of windings of reserve weft Y₁ on the winding surface 1a. Because the blow nozzle 15 is activated immediately after the weft break to divert the broken weft piece into the weft introducing duct 16, insertion of the entire weft piece can be prevented successfully no matter when the weft break occurs. Such rapid prevention of weft insertion after a weft break can make possible easy removal and disposal of the faulty weft left at the cloth fell of the fabric.

[0021] As an incidental matter in connection with the present invention, the apparatus described in the above can perform its intended function of preventing weft insertion and withdrawal of a faulty weft at the cloth fell also in the event of an ordinary failure in weft insertion. The weft portion succeeding the inserted weft portion, when pulled by the paired rollers 23, 24 and tensioned, is cut off from the latter weft portion by a stationary cutter 25 located at the top of the outlet of the main weft inserting nozzle 9.

[0022] Furthermore, even if a weft break occurs on the side up- stream of the weft measuring and storage device 1, the windings of reserve weft on the winding surface 1a can be released immediately and, therefore, prevention of weft insertion can be performed in the same manner as described in the above.

[0023] The apparatus is preventing a broken weft piece Y₁, which results from a weft break taking place adjacently to the outlet of the weft winding tube 1b of the weft measuring and storage device 1 of winding type, from being inserted into a warp shed W, and subsequently withdrawing the weft portion present at the cloth fell W1 of woven fabric by pulling its succeeding weft portion prevented from being inserted.

[0024] The winding amount of reserve weft on the weft winding surface 1a of the weft measuring and storage device 1 is detected by the reserve weft sensor 8. The information from such detection is transmitted to the computer control C, which activates the blow nozzle 15 to prevent weft insertion in response to "no reserve weft" signal from the reserve weft sensor 8.

[0025] In the apparatus according to the present invention, wherein detection of a weft break at a position where the weft break tends to occur most frequently is accomplished by detecting the presence or absence of reserve weft on the weft winding surface of the weft measuring and storage device, prevention of weft insertion subsequent to the weft break can be done rapidly and the subsequent withdrawal of a faulty weft beaten up to the cloth fell of a woven fabric can be carried out merely by pulling the weft portion prevented from being inserted.

DESIGNATION OF REFERENCE NUMERALS

[0026] 1 ... Weft measuring and storage device; 1a ... Weft winding surface; 1b ... Weft winding tube; 8 ... Reserve weft detector; 15 ... Blow nozzle as the means for preventing weft insertion; C ... Computer control as the control means; Y₁ ... Windings of reserve weft.

Claims

1. Weft handling apparatus in a jet loom wherein a reserve weft on a weft measuring and storage device (1) of winding type is released therefrom and inserted into a warp shed (W) by air jet from a main weft inserting nozzle (9), said apparatus comprising:
   means (15, 16) for preventing a weft fly (Y₂) injected from said main inserting nozzle (9) from being inserted into the warp shed (W);
   reserve weft detecting means (8,) for detecting the winding amount of reserve weft on said weft measuring and storage device (1, 1a); and
   control means (C) for controlling the operation of said preventing means (15, 16) according to the information of winding amount of reserve weft from said reserve weft detecting means (8);
   said control means (C) having a function of activating said preventing means (15) when there exists no reserve weft (Y) on the weft measuring and storage device (1).

2. Weft handling apparatus as claimed in claim 1, said means for preventing a weft fly including an air blow nozzle (15), intersecting the air jet from the weft inserting nozzle (9).

3. Weft handling apparatus as claimed in claim 1, said means for preventing a weft fly including an air suction nozzle (15), intersecting the air jet from the weft inserting nozzle (9).

4. Weft handling apparatus as claimed in any of claims 1 to claim 3, said means for preventing a weft fly further including roller means (23, 24) for removing a faulty weft (Y₂).

5. An air jet loom with a weft handling apparatus as claimed in any of claims 1 to 4.

Drawing