YARN GUIDE DEVICE

Abstract: A new weft yarn shall be supplied to a predetermined position in case where the weft yarn in a control unit, particularly in a loom is broken. Conventionally, the supply of the new weft yarn is effected by a weaver. The present invention is to provide a yarn guide device for positioning, holding, transferring a yarn to a predetermined position, drawing the yarn inside of a guide tube located in a predetermined position, and thereafter automatically guiding the yarn to a required device such as a measured and storing device for the weft yarn.

Description: The present invention relates to a yarn guide device with the features of the first part of claim 1. Such yarn guide devices are known from US/A/3 452 910. In this known yarn guide device there arise such problems that firstly, the end of the yarn is unstably sucked into the guide tube, secondly a resistance generated to pull out the yarn from the outer periphery of the yarn package becomes greater than a force to hold the yarn by air friction generated by an air flow under suction inside the guide when the end of the yarn pulled out from the new yarn package is drawn into the guide tube and returned to the original position whereby the end of the yarn is come out from the guide tube. Accordingly, it is an object of the present invention to enable an automatic stable yarn guide. To achieve the object, the present invention is characterized by the features of the second part of claim 1. The above and other objects, features and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings. Fig. 1 is a plan view of a general constitution of a yarn guide device, of a first embodiment according to the present invention; Fig. 2 to 4 are cross sectional views of assistance in explaining various operations of the yarn guide device of Fig. 1 Fig. 5 is a perspective fragmentary view of a tip end of an inserter of the yarn guide device of Fig. 1; Figs. 6 to 8 are cross sectional fragmentary views of a yarn guide device of a second embodiment according to the present invention; Figs. 9 to 11 are views of assistance in explaining various operations of a yarn guide device of a third embodiment according to the present invention; Figs. 12 to 13 are views in explaining various operations of a yarn guide device of a fourth embodiment according to the present invention; Figs. 14 to 15 are cross sectional views of a yarn guide device of a fifth embodiment according to the present ivnention; Figs. 16 to 18 are cross sectional views of a yarn guide device of a sixth embodiment according to the present invention; and Fig. 19 is a cross sectional view of a yarn guide device of a seventh embodiment according to the present invention. In Figs. 1 to 19 illustrating first to seventh embodiments, same reference numerals designate same parts throughout the drawings. Figs. 1 to 5 show a fundamental yarn guide device in a first embodiment according to the present invention. A yarn guide device 1 comprises a guide member 3 fixedly provided at a waiting position of a yarn 2 to be guided in the manner to cross the yarn 2, and a guide tube 4 provided retractably relative to the guide member 3 in a position opposite to and with a predetermined distance from the guide member 3 for drawing the transferred yarn 2 inside thereof and guiding the yarn 2 into a predetermined position. The guide tube 4 has at its inlet portion an engaging member 5 which is provided with a nozzle 6 for jetting an air at the inside thereof and a pair of clamping members 7 at the outside thereof. According to the first embodiment, the yarn 2 are weft yarns which are supplied by two yarn packages and connected with each other at the beginning of winding around one package and at the end of winding around the other package, so called forming a transfer tail, and positioned at the tip end of the guide member 3 located between clampers 9 while the yarns 2 are clamped by the clampers 9. The yarn 2 led from the package 8 passes a larger hole of a yarn guide 10 and is guided into the guide tube 4 via the engaging member 5, and finally guided into a predetermined position, namely, into a measuring and storing device (not shown). The yarn 2 can be cut off by cutters 11 or cylinders 12 for driving the cutters 11 respectively provided at both sides of the guide member 3 at need. An existance of the yarn 2, namely, a state where the yarn is not broken is detected, for example, by a photoelectric sensor 13 while the yarn 2 passes between the yarn guide 10 and the engaging member 4. The guide member 3 is cylindrical as a whole as shown in Figs. 2 to 5. The guide member 3 includes a V-shaped holding groove 14 at the tip end thereof, a tapered hole 15 tapered increasingly from the holding groove 14 toward the inlet portion threof, and a chamber having a stopper 18, a tail stopper 20 and a spring 19. The guide member 3 houses a part of a hollow inserter 16 having a stopper 17 and slides an outer periphery of the stopper 17 of the inserter 16 while urged by the spring 19 arranged between the stopper 17 of the inserter 16 and the stopper 18 of the guide member 3 in the forward movement direction. A forward and backward movement of the guide member 3 are respectively restricted by contacting the stopper 17 with a tail stopper provided inside the guide member 3 and the stopper 17 with a step 21 of the guide member 3. The inserter 16 is decreasngly tapered at its tip end and has a slit 26 on the tapered portion 25 in the direction of generatrix. A bottom portion of the slit 26 is in parallel with a tapered portion 25. A rear end of the inserter 16 is fixedly mounted on a frame of the loom, etc. and connected to a source of air under pressure 24 via a pipe 22, an electromagnetic closing valve. The engaging member 5 is also cylindrical as a whole same as a guide member 3 and pressedly fixed to a tip end of the guide tube 4 at the fit portion 27, and has a cylindrical nozzle 28 inner diameter of which is decreasingly tapered from the guide member 3 toward the guide tube, and a nozzle 6 coaxially arranged with the needle 28. The nozzle 6 has a gap relative to the tip end opening of the needle 28, and connected to a source of air under pressure 24 via a port 29 defined in the engaging member 5, a pipe 30, and an electromagnetic closing valve 31. A pair of clamping members 7 are respectively rotatably supported by supporting pins 33 relative to the engaging member 5, and urged by a coil spring 35 at the rear end piece 24 thereof in the direction to close the tip end thereof. The clamping members 7 are inserted into the engaging member 5 from a longitudinal hole 36 defined in the tip end of the engaging member 5 and the clamping members 7 contact with each other at the holding tongues 32 of the tip end of the clamping members 7 at their center. The rear end pieces 34 of the clamping members 7 is arranged oppositely to hit wedged cams 37 fixed to the frame of the loom at the retracted position or backward movement position of the engaging member 5. The yarn 2 is pulled out from one of the yarn package 8 as shown in solid line in Fig. 1, passes inside the guide tube 4, and is measured by the measruing and storing device, thereafter inserted into a shed of a warp yarn by a picking nozzle, etc. Provided that the yarn 2 is not broken during the sequential operation mentioned just above, the sensor 13 does not issue a stop signal while confirming an existence of the yarn 2. However, provided that the yarn 2 is broken between the yarn package 8 and the yarn guide 10, the sensor issues a stop signal for automatically stop the loom while detecting the breakage of the yarn, whereby the loom is automatically stopped. After stopping of the loom, a remaining yarn is subjected to a disposal by a device, for example the device as disclosed in U.S. Serial No. 903,816 and European Patent Application No. 86112239.8 at the side of the measuring and storing device and the picking device. The yarn guide device 1, after disposal of the yarn 2, starts a sequential operation necessary to pull out a yarn from a new package 8 as shown in imaginary line or two dotted lines. The guide tube 4 is moved in the direction of an arrow shown in Fig. 1 from a retracted position by an air cylinder or a winding unit such as a belt and a chain, to thereby cause the engaging member 5 to pass through the larger hole of the yarn guide 10 and move toward the guide member 3. With the movement of the engaging member 5, a pair of clamping memebers 7 are moved away from the cams 37 so that the clamping members are closed at the end thereof while biassed by a coil spring 35. The engaging member 5 is inserted inside the tapered hole 15 of the guide member 3 as shown in Fig. 2, and moved along the inner surface of the guide member. The engaging member 5 is inserted until it is engaged satisfactorily with the tapered inner surface of the guide member because of elasticity of the guide tube 4. With the engagement of the engaging member 5 and the guide member 3, the guide member 3 and the engaging member 5 are coaxially arranged with each other and a relative positional relation between the pair of holding membes and the guide member 3 are determined. After completion of the engagement, the engaging member 5 moves forward or advances while causing the guide member 3 to be retracted against the resiliency of the spring 19. While the guide member 3 is retracted, a pair of clamping members 7 moves forward and hit the tapered surface 25 of the inseter 16 and opened at the tip end thereof. While the guide member 3 is retracted, the yarn 2 kept in the holding slit 14 is inserted into the slit 26 of the inserter 16, and guided to the portion adjacent to the opening of the needle 28. A part of the slit 26 of the inserter 16 is covered by the holding tongue 32 of the clamping members 7, but not coverted at the root thereof since the slit 26 extends axially in long distance as shown in Fig. 5. The yarn 2 inserted by the inserter 16 between the holding tongue 32 is not restricted by the holding tongue but in a free state. At this state, the closing valves 23, 31 are opened to generate the air flow in the direction to insert the yarn from the inside of the inserter 16 toward the hole of the needle 28, at the same time the air flow in the direction to insert the yarn toward the inside of the guide tube is generated by the nozzle 6. With the generation of the air flows, the cutter at the side where the yarn is broken is actuated to cut off the yarn 2 between the guide member 3 and the clamper 9. Thereafter, the tip end of the yarn 2 is drawn into the inside of the guide tube 4 with the air flow via the inside of the needle 28, and the inside of the nozzle 6. At this time, inasmuch as the guide member 3 and the engaging member 5 are connected with each other, the air flow is not likely to be turbulent so that the yarn 2 is transferred from the guide member 3 to the guide tube 4 with certainty. As shown in Fig. 3, the guide tube 4 is retracted with the engaging member 5 by the feeding device. In the course of retraction of the engaging member 5, a pair of clamping members 7 are moved away from the tapered surface of the inserter 16, and urged by the coil spring 35 to approach to each other to clamp mechanically the yarn 2 extending from the guide member 3 to the guide tube 4 by the holding tongues 32. Thereafter, the closing valves 23, 31 are closed to stop the air flow from the nozzle 6 and the inserter 16. The closing motion of the closing valves 23, 31 may be effected just before the retraction of the engaging member 5. The guide tube 4 and the engaging member 5 are returned to the original waiting position as shown in Fig. 4. At this time, the rear end piece 34 hit again the cams 37 of the pair of clamping members 7 to cause the holding members to be opened so that the yarn 2 is free from the clamping members 7 and drawn by the guide tube 4. That is, at the state in Fig. 4 where the the air under pressure is supplied again from the port 29 to the nozzle 6, the yarn passes inside of the guide tube 4 with the air flow and guided to the inside of the rotative yarn guide automatically provided at the side of the measuring and storing device. After completion of a series of operation mentioned above, preliminary winding on the measuring and storing device and the insertion of yarn into the picking nozzle, the loom is ready to start. The series of operation is sequntially effected by a sequencer which monitors each step of completion of the operation. This is applicable to other embodiments described hereafter. The air flow in the inserter 16 may be generated as a secondary air flow caused by a suction air like the nozzle 6. Although the nozzle 6 is provided at the guide tube 4, but may be provided at the guide member 3. With this arrangement of the nozzle 6, the air flow can be transferred from the nozzle 6 to the inside of the guide tube 4 during the satisfactory time when the yarn 2 reaches the measuring and storing device while the guide member 3 and the engaging member 5 of the guide tube 4 are connected with each other. A second embodiment of the present invention is described with reference to Figs. 6 to 8. The tip end of the inserter 16 is not decreasingly tapered but provided with a V-shaped groove 38, and closing motion of the holding members 7 is controlled by a cylinder 39. The V-shaped groove 38 is defined to be directed in the same direction as the holding groove 14 of the guide member 3, and the yarn 2 is positioned inside the holding groove 14 at the first stage of operation. A cylinder 39 is provided at the side of the engaging means 5 and moved with the engaging means 5 to cause the pair of clamping members 7 to open at the advanced position and to close at the time of retraction to hold the yarn 2 between the clamping members 7. At the position of the retraction position, the clamping members release the yarn 2 which is then drawn into the inside of the guide tube 4 and guided to the predetermined position. Inasmuch as no air flow is generated from the inserter 16 according to the second embodiment, the yarn 2 is drawn only by the secondary air flow generated by the nozzle 6 at the side of the engaging member 5. A third embodiment of the present invention will be described with reference to Figs. 9 to 11. Closing motion of a pair of clamping members 7 according to the third embodiment is effected by permanent magnets 40, 41, 42. Magnetic force of the permanent magnet 42 is greater than that of the permanent magnet 41. The permanent magnet 40 provided at the guide member 3 attracts the tip ends of the clamping members 7 to open the tip ends when the engaging member 5 moves toward the guide member 3. When the engaging member 5 is moved backward or retracted, the permanent magnets 41 provided oppositely with each other at inner surfaces of the holding tongue 32 attracts each other to close the clamping members 7 to clamp the yarn 2. The force to clamp the yarn 2 is increased by intervening the rubber and the like having greater frictional coefficient at the clamping surfaces of the holding tongues 32. The clamping members are released from their holding state in the manner that the clamping members are attracted by the pemanent magnets 42 provided at the cams 37, and the yarn 2 is drawn by the suction nozzle provided at the engaging member 5 via the needle 28. A fourth embodiment of the present invention will be described with reference to Figs. 12 and 13. The guide member 3 is movable toward and away from the fixed guide tube 4 according to the fourth embodiment which is different from the first to third embodiments. A pair of clamping members 7 are provided at both sides of the movable guide member 3 and the cams 37 are provided at the portion adjacent to a retracted position of the guide member 3 where the cams 37 hit the rear end piece 34 of the clamping members 7, to open the holding tongues 32. When the guide member 3 is moved forward or advanced to hit the tapered end surface 43 of the engaging member 5 a pair of clamping members 7 hit the slant surfaces of a pair of cams 44 to open the holding tongue 32 and release the yarn 2. A fifth embodiment of the present invention will be described with reference to Figs. 14 and 15. The guide tube 4 is fixed same as that in fourth embodiment. The engaging member 5 is omitted according to the fifth embodiment as evident from the comparison with the third embodiment of Fig. 10. The guide member 3 defines a cylinder 45 in which a slider 46 fixed to the inserter 16 is housed. The slider 46 is urged by a spring 19 in the direction to retract from the bottom portion of the cylinder 45 and the retraction limit is restricted by a tail stopper 20. Two supporting pins 33 for a pair of clamping members 7 are respectively fixed to the slider 46 through the elongate slit 47. A pair of clamping members 7 release at the waiting position the yarn 2 while striding over the yarn 2 restricted by the holding groove 14. Upon the advancement of the guide member 3, a pair of clamping members are moved away from the cams 37 to hold the yarn. Upon further advancement of the guide member 3 to cause the end surfce 48 to contact with the end surface of the guide tube 4, the slider 46 slides inside the cylinder 45 of the guide tube 3 against the urging force of the spring 19 with the movement of the inserter 16, at the same time the clamping members 7 are inserted into the guide tube 4. At this time, inasmuch as the clamping members 7 release the yarn by the cam 47, the yarn 2 is drawn into the guide tube 4 by the suction force of the nozzle 6. According to the fifth embodiment, inasmuch as the yarn 2 is sealed by the complete connection of the guide member 3 and the engaging member 5 and then the yarn 2 is released by the clamping members 7, there is such an advantage that the yarn 2 is drawn into the guide tube 4 more easily than that of fourth embodiment. As evident from the first embodiment to fifth embodiment, the guide member 3 and the guide tube 4 may move to the position to pass the yarn to each other, hence any of or both of the guide member 3 and the guide tube 4 can move solely or respectively. A sixth embodiment of the present invention will be described with reference to Figs. 16 to 18. The yarn 2 is transferred positively to the engaging member 5 by the forward or backward movement of an auxiliary inserter 51 without use of the air flow in the inserter 16. The inserter 16 has a rear end fixed to a tip end of a cylindrical holder 49. The holder 49 has a rear end fixed to a bracket 50 and inserted into the cyindrical guide member 3. The inserter 16 and the holder 49 retain therein the auxiliary inserter 51 in a retractable state. The auxiliary inserter 51 has a tip end provided with a holding groove 52 and a rear end connected with a piston rod 56 of an air cylinder 55 via a flexible coupling 53 such as a coil spring, and a connecting rod 54. The air cylinder 55 is fixed to a side surface of the bracket 50 by a guide member 57 for guiding the connecting rod 54. The engaging member 5 is substantially same as that in the first embodiment as shown in Fig. 1. When the guide tube 4 is moved to the advanced limit, the air under pressure is introduced from the port 29 and simultaneously the piston rod 56 of the air cylinder 55 is forwardly moved by the air cylinder 55 to thereby cause the tip end of the auxiliary inserter 51 to move toward a throat of the tapered portion of the needle 28. With the movement of the arrangement, the yarn 2 engaged by the slit 26 of the inserter 16 and being in a positioning state is engaged by a holding groove 52 of the auxiliary inserter 51 with certainty as shown in Fig. 17, whereby the yarn 2 is released from the slit 26, inserted from the suction port of the needle 28 and reaches the throat of the tapered portion of the needle 28. Inasmuch as the air under pressure is introduced into the air inlet port 29 the air flow in the direction for drawing yarn is generated inside the guide tube 4, and at the same time the air flow in the direction for drawing yarn is generated inside the needle 28 due to the suction in the restriction portion of the needle 28. A speed of the air flow under suction in the throat of the needle is greater than the suction port, and the yarn 2 is exposed to the air under suction for a longer length so that the yarn 2 with the high air stream is moved away from the holding groove 52 of the auxiliary inserter 51, passes inside the needle 28, and reaches the inside of the guide tube 4 with ease. A seventh embodiment of the present invention will be described with refeence to Fig. 19. Although the yarn guide device in the sixth embodiment has the inserter 16 fixed to the bracket 50 by the holder 49 and the auxiliary inserter 14 is movable by the air cylinder 55, the forward movement of the auxiliary inserter 14 can be achived by utilizing the retractable movement of the guide tube 4 as shown in Fig. 19. According to the seventh embodiment, the auxiliary inserter 51 is fixed to the bracket 50 and the inseter 16 is integrated with the holder 49 so that the inserter 16 and the holder 49 are slidable relative to the auxiliary inserter 51 by the tail stopper 20 which guides and slidable over the holder 49. The engaging member 5 hits the guide member 3, then retracts the guide member against the resiliency of the spring 19. Thereafter, inasmuch as the step 21 hits the stopper 17, then moves further forwardly against the resiliency of the coil spring 58, the fixed auxiliary inserter 51 moves in the forward direction relative to the inserter 16 for thereby guiding the yarn 2 to the inside of the needle 28.

Claims: A yarn guide comprising: a guide member (3) for positioning and holding a yarn (2) to be inserted; a guide tube (4) for drawing the yarn (2) inside said guide tube (4) and guiding the yarn (2) in a predetermined position; said guide member (3) and said guide tube (4) being retractable relative to each other in the direction to approach to each other; at least one of said guide member (3) and said guide tube (4) having a nozzle (6) for generating an air flow for transferring the yarn to said guide tube (4); characterised in that a pair of clamping means (7) are provided on said guide member (3) or guide tube (4) for mechanically clamping the positioned yarn (2) and releasing the yarn (2) after the yarn (2) is transferred toward said guide tube (4). A yarn guide device (1) according to claim 1, characterised in that said guide member (3) having inside thereof an inserter (16) for transferring the yarn (2) to said guide tube (4). A yarn guide device (1) according to claim 2 wherein said inserter (16) has a slit for holding the yarn (2) at the tapered tip end thereof. A yarn guide device (1) according to claim 2 or 3 wherein said inserter (16) is hollow and has an auxiliary inserter (51) therein, said auxiliary inserter being retractable in the direction of transferring the yarn (2). A yarn guide device (1) according to claim 4, wherein said auxiliary inserter (51) is connected to a source (55) for driving said auxiliary inserter (51). A yarn guide device (1) according to claim 4, wherein said inserter (16) is biased by a coil spring (58) relative to said auxiliary inserter (51) in the direction of forward movement of said inserter (16). A yarn guide device (1) according to one of the preceding claims, wherein said pair of clamping means (7) are urged by a spring (35) in the direction to clamp the yarn (2), releasing the yarn (2) upon hitting cams (37) at the position for transferring the yarn (2). A yarn guide device (1) according to one of the claims 1 - 7, wherein closing motion of said pair of clamping means (7) is effected by a plunger (39) connected thereto. A yarn guide device (1) according to one of the claims 1 - 7, wherein said pair of clamping means (7) are attracted to each other by first permanent magnets disposed therein to close said clamping means for clamping the yarn (2), and attracted to said cams (37) by second permanent magnets magnetic force of which are greater than that of said first permanent magnets and dispose on said cams (37) to open said clamping means (7) for releasing the yarn (2). A yarn guide device (1) according to one of the preceding claims wherein a portion of said guide member (3) opposed to said guide tube (4) is composed of a cylinder having an axis in the direction to draw the yarn (2) and a holding groove (14) provided at the end thereof for holding the yarn (2).

Inventors: MATSUDA, FUMIO, TAKEHANA, TATSUO
Applicants: TSUDAKOMA CORPORATION
Application year: 1988
Main classification: D03D47
IPC codes: D03D47