DETAILED DESCRIPTION OF THE INVENTION
INDUSTRIAL FIELD OF UTILIZATION
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The present invention relates to a weft handling method and an apparatus for performing said method. More specifically, it relates to a method of feeding a new weft to a weft inserting main nozzle subsequent to occurrence of any weft break in a jet loom including a weft supply cheese and a weft measuring device adapted to receive weft from the cheese and to measure a predetermined length of weft which is to be inserted for each pick into a warp shed by the main nozzle, and also to an apparatus for performing the method.
PRIOR ART
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In a conventional jet loom disclosed, e.g. by Publication of Unexamined Japanese Patent Application 59-228047 (1984), if the leading end of an inserted weft fails to reach a position defined by a weft sensor located on opposite side of a warp shed, i.e. in the event of a failure in weft insertion throughout the shed, the faulty weft is cut at an appropriate position and portion of the weft woven to a fabric is pulled out thereof toward the weft inserting side for removal of the faulty weft by a suction nozzle located between a weft inserting main nozzle of the loom and the warp sheets.
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It is noted, however, that the above method is unable to cope with a failure in weft insertion due to a weft break taking place between a weft supply cheese and the main nozzle.
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In order to solve the above problem, an improved method is proposed by Publication of Unexamined Japanese Patent Application 2-112448 (1990), according to which the faulty weft in the warp shed is removed therefrom and subsequently a weft leading from its supply cheese is extended to the main nozzle along normal weft passage. In this method, if a weft break occurs at any position between a drum type weft measuring device and the main nozzle, the weft is cut by a cutter located at a position adjacent a weft withdrawing device provided just upstream of the weft measuring device and residual windings of reserve weft on the weft measuring device are removed by the weft withdrawing device while releasing the residual reserve weft from the measuring device by rotating its winding arm in reverse direction. In the event that a weft is broken at a position upstream of the weft measuring device, on the other hand, the residual reserve weft is released and then removed under the influence of strong suction created by activating the main nozzle. In either case, after disposing of the unnecessary weft, a new weft leading from a cheese is fed to the weft measuring device by air stream from a feed nozzle, guided through a weft guide and then introduced into the main nozzle by suction developed by air jet injected therefrom.
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Removal of the windings of residual weft on the weft measuring device, which is done subsequent to a weft break between the weft measuring device and the main nozzle and accomplished by rotating its winding arm in reverse direction according to the above method, has a disadvantage in that the apparatus for performing the method is complicated in construction because the rate of reversing the winding arm must be controlled in close relation to the weft pulling force by the weft withdrawing device. On the other hand, the process of allowing the residual windings of weft released from the weft measuring device to be discharged through the main nozzle in case of a weft break at a position upstream of the weft measuring device may cause the main nozzle to be clogged with weft because the free trailing end of the weft formed by the break may flutter without moving straight when entering into the main nozzle and also the trailing end portion of the weft may be released from the weft measuring device in a wound or coiled state. Thus, a weft cannot be passed through the main nozzle smoothly as during normal weaving operation, but causing the main nozzle to be blocked with the residual weft to be discharged.
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In the above method, the process of disposing of a residual weft differs depending on where the weft break has taken place. It is necessary, therefore, to recognize accurately the position of weft break and the use of various sensors is be required, which will make the apparatus more costly and complicate the controlling.
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An apparatus is proposed by Publication of Unexamined Japanese Patent Application 2-210043 (1990) which can permit smooth passing a new weft through the main nozzle without reversing the weft winding arm of the weft measuring device. In this apparatus, if a weft break takes place at a position between the weft measuring device and the main nozzle, the windings of residual weft on the weft measuring device are removed therefrom by air stream from a blow nozzle located upstream of the device and carried to a booster adjacent the main nozzle for disposal of the residual weft. Upon cutting the weft in the booster by a cutter, the cut-off portion of the weft is taken out from the booster by suction and the remaining portion of the weft is fed to the main nozzle by air stream generated by air jet from the main nozzle alone or in cooperation with a mechanical fork.
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According to this method, however, it requires a strong suction force to introduce the cut leading end of the weft into the main nozzle by suction alone created by air jet from the main nozzle. This will inevitably increase air consumption. The use of the mechanical fork in conjunction with the air suction is disadvantageous in terms of operational reliability because the fork is required to make accurate motion in order to permit the weft to be introduced properly into the main nozzle. Thus, this proposed method is difficult to be put into practical use.
[PROBLEMS THAT THE INVENTION IS TO SOLVE]
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It is an object of the present invention to solve the aforementioned disadvantages and drawbacks of the conventional methods and apparatuses in a jet loom for feeding a new weft subsequent to occurrence of a weft break. That is, the invention is intended to provide a method which can permit the new weft to be passed through the nozzle rapidly and safely without causing the nozzle to be clogged with the weft, as well as an apparatus for performing the method.
[MEANS SOLVING THE PROBLEMS]
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In order to achieve the above object, the invention provides a method of feeding a new weft through a weft inserting main nozzle in a jet loom subsequent to occurrence of any weft break, said loom having a weft supply cheese and a weft measuring device, wherein, in the event of occurrence of a weft break between the weft cheese and the main nozzle, a weft extending along its normal passage between a position upstream of the weft measuring device and the outlet end of the main nozzle is removed from the weft passage and thereafter a new weft from the cheese is passed through the weft measuring device and then through the main nozzle, and, in the event of occurrence of a weft break at any position between the weft measuring device and the main nozzle, the weft is cut at a position between the cheese and the weft measuring device and thereafter a weft piece resulting from the weft break and the cutting is removed at a position between the weft measuring device and the main nozzle.
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The invention further provides an apparatus of feeding a new weft through a weft inserting main nozzle in a jet loom subsequent to occurrence of any weft break wherein said loom includes a weft supply cheese and a weft measuring device and wherein a weft supplied from said cheese is passed through said weft measuring device for measurement and storage of a predetermined length of the weft for each pick and the weft is ejected through the main nozzle by an air jet injected therefrom, said apparatus including weft feeding means and weft cutting means both disposed between the weft supply cheese and weft measuring device and weft discarding means disposed between the weft measuring device and the main nozzle.
[OPERATION OF THE INVENTION]
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If a weft break has taken place between the weft cheese and the main nozzle, a weft extending along a normal weft passage between a position upstream of the weft measuring device and the outlet end of the main nozzle is removed from the weft passage and thereafter a new weft from the cheese is passed through the weft measuring device and then through the main nozzle and, therefore, the weft does not have to be passed through the main nozzle, so that the main nozzle is free from clogging with the weft.
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If a weft break has occurred at any position between the weft measuring device and the main nozzle, the weft is cut at a position between the cheese and the weft measuring device and thereafter a free weft piece is removed at a position between the weft measuring device and the main nozzle, with the result that weft removal can be performed in the same manner as in the above case. In addition, winding arm or any similar means of the weft measuring device does not have to be rotated reverse.
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In the latter case, because a new weft having its leading end formed by the cutting is released from its cheese and then fed by the aid of weft feeding means, it can be passed easily through the weft measuring device by using fluid under pressure. Additionally, provision of any means disposed adjacently to the weft measuring device for transferring the weft to the weft discarding means can help the weft to pass through the main nozzle safely and rapidly.
[EMBODIMENTS]
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The following will describe an embodiment of apparatus according to the present invention while making reference to the accompanying drawings.
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Referring to FIGS. 1 and 2, reference numeral 1 designates a weft cheese from which a weft W is released to be fed through a weft feed nozzle 4 toward a weft measuring device 12. The weft W passing through a weft winding arm 11 of the weft measuring device 12 is wound round a weft measuring surface 12a of the device to form windings of reserve weft of a predetermine length. The nozzle 4 has a weft sensor 3.
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The reserve weft on the surface 12a is released therefrom and inserted into a warp shed then formed by warp sheets Y by air jet from a weft inserting main nozzle 20 connected to a solenoid valve V5. In this embodiment, a reserve weft cheese 1' is provided which has the free end of its weft received in a nozzle 2 located between the paired cheeses 1, 1'. The nozzle 2 connected to a solenoid valve V1 is activated to inject air for releasing the free end of its weft and directs it toward the weft feed nozzle 4 when the sensor 3 detects a weft break between the weft cheese 1 and the weft measuring device 12.
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A weft cutter 5 is disposed immediately below the weft feed nozzle 4 for cutting weft W extending between the weft cheese 1 and the weft measuring device 12 when a break takes place at any position between the weft measuring device 12 and the main nozzle 20, so that continuity of reserve weft on the weft winding surface 12a and the weft extending from the cheese 1 is cut off thereby to make possible removal of the residual reserve weft. The weft measuring device 12 includes a drum 10 having a motor 10a and a winding arm 11. The drum 10 further includes a weft inlet 6 for guiding the weft W into the winding arm 11 and a blow nozzle 7 for issuing air stream toward the inlet of the weft winding arm 11.
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On the weft measuring device 12 is provided a guide plate 9 having a trough shape and directed toward weft discarding means 14, which is to be described in detail hereinafter, for guiding a weft toward the weft discarding means 14 by air stream generated by a weft guide nozzle 8. That is, this guide plate 9 provides means for transferring a weft from the weft measuring device 12 to the weft discarding means 14. The nozzles 4, 7, 9 are connected to a common solenoid valve V2. The device 12 further includes a solenoid-operated stop pin 13 which can be moved into and away from engagement with the weft winding surface 12 for reserving and releasing windings of reserve weft of a predetermined length round the surface 12. The weft discarding means 14 includes an intermediate nozzle 18 which serves as an guide nozzle for guiding a weft toward the main nozzle 20 during passing of a weft therethrough subsequent to any weft break, as well as during normal weaving operation. The intermediate nozzle 18 is connected to a solenoid valve V4. The weft discarding means 14 further includes a blow nozzle 15 connected to a solenoid valve V3 for directing air stream toward a dust pipe 16 disposed in opposition to the blow nozzle 15. Below the dust pipe 16 is located a trash box 17 for receiving discarded weft pieces.
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Reference numeral 19 in FIG. 1 designates a well-known device disposed between the main nozzle 20 and the warp sheets Y. This device 19 has two functions of removing a faulty weft from the cloth fell of a woven fabric C and of preparing a new weft for insertion by cutting a weft passed through the main nozzle 20 with a cutter 20a located at the outlet of the main nozzle thereby to form a definite cut leading end of the new weft. This device 19, which is referred to as first weft removing device hereinafter, includes blow nozzle 22 connected to a solenoid valve V6 for issuing air stream to direct a weft coming out of the main nozzle 20 into a pipe disposed on opposite side of the main nozzle. The device 19 further includes a pair of rollers, i.e. a nip roller 19b rotatable by a motor 19a and an idle roller 19c movable by an air cylinder 19d into and away from contact engagement with the nip roller 19b. The air cylinder is connected to a solenoid valve V8. There is also provided a weft sensor 21 in the device 19. As shown in FIG. 2, there are provided a first weft sensor S1 on the opposite side of the warp sheets with respect to the weft insertion side for detecting the leading end of a properly inserted weft and a second weft sensor S2 located at a position beyond the first weft sensor S1 where a properly inserted weft will not reach. Though not shown in the drawing, a second weft removing device is disposed further beyond the second weft sensor S2 for removing a faulty weft from the cloth fell of a woven fabric C.
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If a weft break is detected by the weft sensor 3 or the second weft sensor S2, weaving operation of the loom is stopped. After a faulty weft between the warp sheets has been removed by the first weft removing device 19, the apparatus shown in FIG. 1 is operated according to the control program shown by way of a flow chart in FIG. 3 in response to control signals transmitted from a control unit (not shown). It is noted that a weft break detected by the sensor 3 represents a break between the weft cheese 1 and the weft measuring device 12, while a weft break detected by the sensor S2 represents a break taking place downstream of the weft measuring device 12. As shown in the flow chart of FIG. 3, firstly the solenoid valve V3 is opened thereby to activate the blow nozzle 15 of the weft discarding means 14. Simultaneously, the solenoid for the stop pin 13 is energized to disengage the latter pin from the weft winding surface 12a to release the windings of reserve weft and the solenoid valve V2 is opened to activate the weft feed nozzle 4, blow nozzle 7 and weft guide nozzle 8. Then, the weft cutter 5 is actuated to make a cut of the weft between the cheese 1 and the weft measuring device 12. Thus, the resulting free weft piece is blown by air stream form the blow nozzle 14 into the trash box 17 through the dust pipe 16. After elapse of a predetermined period of time, the solenoid valve V2 is closed to stop air injection from the nozzles 4, 7, 8. Then, the valve V3 is also closed to stop air injection from the blow nozzle 15.
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Subsequently, the solenoid valves V4, V5, V6, V7 are opened to activate the intermediate nozzle 18, main nozzle 20 and blow nozzles 22, 23, respectively. If the weft sensor 3 then detects no weft in the nozzle 4, the solenoid valves V2 and V1 are opened to carry the leading end of a new weft from the reserve cheese 1' to the first weft removing device 19. On the other hand, if the weft sensor 3 then detects the presence of a weft in the nozzle 4, only the valve V2 is opened to carry the leading end of the weft from the cheese 1 to the first weft removing device 19.
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After elapse of a predetermined period of time, the solenoid valves V1, V2, V4, V5, V6, V7 are all closed to stop air injection from their associated nozzles. If the sensor 21 of the second weft removing device 19 then detects no weft, the control goes back to the beginning of the control program of FIG. 3 to repeat the above steps of procedure. If the sensor 21 continues to detect no weft ever after a predetermined number of repetitions of the steps, an alarm, e.g. a warning lamp mounted on the loom, will be energized.
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If the weft sensor 21 detects a weft extending therethrough, the control proceeds to the program shown in FIG. 4. That is, upon detection of a weft by the sensor 21, the solenoid valves V7, V8 are opened to activate the nozzle 23 and the air cylinder 19d, thereby blowing air from the nozzle and moving the idle roller 19c into contact engagement with its associated nip roller 19b. Simultaneously, the stop pin 13 is moved into engagement with the weft winding surface 12a and the motor 10a is rotated for a predetermined number of turns to form a reserve weft on the surface 12a.
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Then, the motor 19a is started to drive the paired rollers 19b, 19c until the sensor 21 detects the weft no more. During rotation of the rollers 19b, 19c, the weft nipped therebetween is pulled and blown for disposal by air stream from the blow nozzle 23. The weft leading from the weft measuring device 12 is the subjected to tension by the pulling until it is cut by the weft cutter 20a. Thus, the leading end of a new weft to be inserted is formed by this cutting. When no weft is detected by the sensor 21, the motor 19a is stopped and the valves V7, V8 are closed to stop air injection from the blow nozzle 23 and to retract the idle roller 19c from the nip roller 19b. Thus, the operation of the first weft removing device 10 to remove a faulty weft from the cloth fell of woven fabric C and of preparing a new weft for insertion is completed.
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Now referring to FIGS. 5-8, the following will describe the manner of preparing a new weft subsequent to occurrence of a weft break between the weft measuring device 12 and the main nozzle 20. This weft break can be detected by the second weft detector S2. In response to such detection, the loom is stopped and then rotated reverse to release the last inserted weft from the warp sheets. This weft piece is removed by the first and/or second weft removing devices. Then, windings of residual weft remain on the weft winding surface 12a of the weft measuring device 12, as shown in FIG. 5. With the nozzles 4, 7, 8 opened and the stop pin 13 disengaged, the leading end of the residual weft is introduced toward the intermediate nozzle 14 and then withdrawn toward the trash box 17 by air stream from the nozzle 15, as shown in FIG. 6. The weft is cut by the cutter 5 to allow the residual weft to be discarded into the trash box 17, as shown in FIG. 7.
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After such removal of the residual weft, the blow nozzle 15 is closed and then weft removal and preparation of a new weft are performed by the first weft removing device 19 in the manner as described above. It is noted that FIG. 8 shows a state where the leading end portion of the weft has been already cut off by the weft cutter 20a.
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Now reference is made to FIG. 9 showing a case in which a weft break has taken place between the weft cheese 1 and the weft measuring device 12. In this case, disposal of the residual weft on the weft winding surface 12a is done in the same manner as in the above case of a weft break between the weft measuring device 12 and the main nozzle 20, except that the weft break is detected by the weft sensor 3 and no weft cutting is effected by the cutting stroke of the weft cutter 5 (FIG. 10). It could be now understood that, because the same steps of procedure can be used to cope with weft breaks occurring at different positions, the method of controlling the apparatus can be simplified.
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Prior to transferring the weft to the first weft removing device 19 for preparation of a new weft for insertion, the solenoid valve V1 is opened to inject air for introducing the leading end of a weft from the reserve cheese 1' into the weft feed nozzle 4, as shown in FIG. 11. The preparation of a new weft for insertion by the weft removing device 19 is done in the same manner as in the above case described with reference to FIGS 5-8. Incidentally, FIG. 12 shows a state in which the weft from the reserve weft cheese 1' has been transferred to the weft removing device 19.
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FIGS. 13 and 14 illustrate another embodiment of the present invention. This embodiment differs from the above-described first embodiment in that the weft discarding means 14 of the latter embodiment is substituted with means 24. That is, the weft discarding means 24 includes a groove 12b formed in the weft winding surface 12a, a weft guide 26 having an inclined end, an air cylinder 25 operable to move the weft guide 26 into and away from the groove 12b, and a suction pipe 27 having its suction port 27a located adjacent the weft guide 26 and directed toward the weft winding surface 12a.
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In the event of a weft break between the weft measuring device 12 and the main nozzle 20, the loom is stopped, the stop pin 13 is disengaged, and the cutter 5 is actuated to make a weft cut. Then, the air cylinder 25 is actuated to move weft guide 26 down into the groove 12b so that the residual reserve weft on the winding surface 12a is pushed out therefrom by the inclined end of the weft guide 26 and withdrawn through the suction pipe 27 for disposal of the weft piece. In this embodiment, preparation of a new weft by the first weft removing device 19 is done in the manner as in the first embodiment, except that the weft from the weft measuring device 12 is directly introduced into the main nozzle 20 without passing through the weft discarding means 24. Reference symbol W' in FIG. 13 designates the passage of a weft transferred to the main nozzle 20 for preparation of a new weft.
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In the event of a weft break between the cheese 1 and the weft measuring device 12 in the second embodiment, disposal of the residual weft is done in the same manner as in the above case of a weft break taking place between the weft measuring device 12 and the main nozzle 20, except that no weft cutting is effected by the cutting stroke of the weft cutter 5. Transferring of a weft to the first weft removing device 19 is started with activating the nozzle 2' for the reserve weft cheese 1' to direct a weft therefrom toward the weft inlet 6 of the winding arm 11. The manner of the subsequent transferring of a weft to the device 19 is substantially the same as in the first embodiment, except that no intermediate nozzle such as 18 is used.
[EFFECT OF THE INVENTION]
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As it would be now apparent to those skilled in the art, the method of controlling the apparatus can be simplified because disposal of residual weft piece can be done in the same manner regardless of the position where the weft break takes place. Furthermore, because the residual weft is not removed by passing it through the main nozzle, the nozzle will not be clogged with residual weft. Additionally, leading the weft through the weft measuring device can make possible safe and rapid passing of the weft through the main nozzle.
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To provide an apparatus and a method of feeding a new weft through a weft inserting main nozzle in a jet loom subsequent to occurrence of any weft break, which apparatus and method can prevent the main nozzle from being clogged with a weft to be discarded and also permit the new weft to be passed through the main nozzle rapidly and safely.
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The method is characterized in that, in the event of occurrence of a weft break between a weft supply cheese and the main nozzle, a weft extending along the normal weft passage between a position just upstream of a weft measuring device and the outlet end of the main nozzle is taken out from the weft passage and, thereafter, a new weft extending from the cheese is passed through the weft measuring device and then through the main nozzle. The apparatus is characterized in that it includes a weft feeding means and a weft cutter between the weft cheese and the weft measuring device, and weft discarding means between the weft measuring device and the main nozzle.
[BRIEF EXPLANATION OF THE DRAWINGS]
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- FIG. 1 is a schematic illustrative view showing the first embodiment of weft handling apparatus of the invention as seen on the side of weft insertion in a jet loom;
- FIG. 2 is a schematic plan view showing the apparatus of FIG. 1 as seen on the opposite side of the jet loom;
- FIG. 3 is a diagram showing part of the flow chart of control program for weft handling by the apparatus;
- FIG. 4 is a diagram showing part of the flow chart of the control program;
- FIG. 5 is an illustrative view showing a state in which a weft break has occurred between a weft measuring device and a main nozzle of the jet loom;
- FIG. 6 is an illustrative view showing a state in which residual weft has been removed from the weft measuring device and introduced into a weft discarding means;
- FIG. 7 is an illustrative view showing a state in which the weft has been cut off between a weft supply cheese of the jet loom and the weft measuring device;
- FIG. 8 is an illustrative view showing a state in which a weft from the cheese has been transferred through the main nozzle to a weft preparation device of the apparatus;
- FIG. 9 is an illustrative view showing a state in which a weft break has occurred between the weft cheese and the weft measuring device;
- FIG. 10 is an illustrative view showing a state in which residual weft has been removed from the weft measuring device and then discarded;
- FIG. 11 is an illustrative view showing a state in which a weft from a reserve weft cheese of the jet loom has been released therefrom and passed through a weft feed nozzle for transferring of the weft through the main nozzle to the weft preparation device;
- FIG. 12 is an illustrative view showing a state in which the weft from the cheese has been transferred through the main nozzle to the weft preparation device;
- FIG. 13 is a schematic illustrative view showing the second embodiment of weft handling apparatus in a jet loom according to the present invention;
- FIG. 14 is an enlarged view showing part of the apparatus of FIG. 13.
[DESIGNATION OF REFERENCE NUMERALS]
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- 1
- Weft supply cheese
- 1'
- Reserve weft supply cheese
- 2, 2'
- Nozzles for releasing weft from reserve cheese
- 3
- Weft sensor
- 4
- Weft feed nozzle
- 5
- Weft cutter
- 6
- Weft inlet
- 7
- Blow nozzle
- 8
- Weft guide nozzle
- 9
- Guide plate
- 10
- Drum
- 11
- Winding arm
- 12
- Weft measuring device
- 12a
- Weft winding surface
- 13
- Stop pin
- 14
- Weft discarding means
- 15
- Blow nozzle
- 17
- Trash box
- 18
- Intermediate nozzle
- 19
- First weft removing device
- 20
- Weft inserting main nozzle
- 21
- Weft sensor
- 22, 23
- Blow nozzles
- 24
- Weft discarding means
- 25
- Air cylinder
- 26
- Weft guide
- 27
- Suction pipe
- Y
- Warp sheets
- W
- Weft
- S1
- First weft sensor
- S2
- Second weft sensor
- C
- Woven fabric
