Picking apparatus in rapier loom

Abstract: The present invention relates to a picking apparatus (1) in a rapier loom. The apparatus has gripping bodies (2, 3) beween a weft selection device and a yarn cutter (14). The gripping bodies (2, 3) are movable up and down. The gripping bodies (2, 3) selectively grip a plurality of weft yarns (9a, 9b) in accordance with a color pattern. One yarn cutter (14) cuts the weft yarn (9a or 9b) gripped by the gripping bodies (2 or 3) and severs the cut weft yarn (9a or 9b) from a woven cloth (9) after the weft yarn (9a or 9b) is picked. According to the present invention, neither catch cords nor extra length fringe nor a selvage cutter is needed.

Description: The present invention relates to a picking apparatus in a rapier loom with the features of the pre-amble of claim 1, which apparatus is known from CH-A-520 217. In a rapier loom as known from JP-A-54-73967, catch cords are provided outside a selvage of a woven cloth which hold a picked weft yarn while the picked weft yarn is connected to a yarn package. The weft yarn is cut by a yarn cutter between the catch cords and a rapier at the start of the next picking operation of the weft yarn, then the weft yarn is picked. The weft yarn end held by the catch cords is cut from the selvage of the woven cloth by a selvage cutter and thrown away with the catch cords. The catch cords are necessitated for holding the weft yarn at the picking operation in the rapier loom, which entail in loss of the weft yarn held thereby, i.e., the extract length fringe. Furthermore, there are provided a yarn cutter and a selvage cutter which are liable to fail, a special attention is required to be paid for maintenance and inspection thereof. It is therefore an object of the present invention to provide a picking apparatus in a rapier loom capable of eliminating catch cords which entail in loss of the weft yarn and the selvage cutter. To achieve the above object, the picking apparatus in the rapier loom is provided with the features of claim 1. Preferred embodiments of the invention are subject matter of the subclaims. According to the present invention, the picked weft yarn is gripped by the first gripping body and the gripper of the slider or the second gripping body and the gripper of the slider outside the picking side selvage of the woven cloth and is cut by the yarn cutter provided between the gripping bodies and the woven cloth at an appropriate timing which results in eliminating the catch cords and generating no extra length fringe. Accordingly, the loss of the weft yarn can be saved to a great extent and no selvage cutter is necessitated due to non-existence of the extra length fringe. As a result, the weft yarn can be cut by only one yarn cutter which entails to omit the cutter which is troublesome in maintenance and inspection thereof and omit the time and labor involved in such maintenance and inspection. The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings. Fig. 1 is a side elevational view of a picking apparatus in a rapier loom according to a first embodiment of the present invention; Fig. 2 is a plane view of the picking apparatus in Fig. 1; Fig. 3 is a front elevational view of a part of the picking apparatus in Fig. 1; Fig. 4 is an exploded perspective view showing a principal portion of the picking apparataus in Fig. 1; Fig. 5 is a view showing a cam line relative to a turning angle of a main shaft of the rapier loom in Fig. 1; Fig. 6 is a perspective view showing a disposition of the principal portion of the picking apparatus in Fig. 4; Fig. 7 is a view of assistance in explaining operation of the picking apparatus in accordance with two color alternate pick weave (a colr pattern 1 x 1); Fig. 8 is a view of assitance in explaining an opertion of a picking apparatus in a rapier loom according to a second embodiment of the present invention; Fig. 9 is a view of assistance in explaining an operation of the picking operation in accordance with two color alternate two pick weave (a color pattern 2 x 2); Fig. 10 is a view of assistance in explaining an operation of the picking apparatus according to other color pattern; Fig. 11 is a view of assistance in explaining a driving means according to a third embodiment of the present invention; Fig. 12 is a view of assistance in explaining a gripper, a slider and a yarn cutter respectively constituting the driving means in Fig. 11; Figs. 13 and 14 are tables of assistance in exaplaining switching signals; Fig. 15 is a front elevational view of a driving means according to a fourth embodiment of the present ivnention; Fig. 16 is a block diagram showing a rotation control circuit in Fig. 15; and Fig. 17 is a perspective view of a yarn guide according to a modified embodiment of the present invention. First Embodiment (Figs. 1 to 7): A picking apparatus in a rapier loom according to a first embodiment of the present invention will be described with reference to Figs. 1 to 7. A picking apparatus 1 in a rapier loom comprises, as illustrated in Figs. 1 to 4, first and second gripping bodies 2, 3, a block shaped slider 4 and a driving means 5. These elements 2, 3, 4 and 5 are incorporated in first and second brackets 6, 7. That is, the first bracket 6 is attached to a loom frame, not shown, between fingers 8a, 8b of a weft selection device and a woven cloth 9. The bracket 6 has a slider shaft provided vertically at an open end of the front portion thereof and supports the slider 4 vertically movably along the slider shaft 10. The slider 4 has a gripper 11 incorporated therewith at the front central portion thereof. The gripper 11 has a movable blade 12 at the side of a woven cloth 9. The movable blade 12 and a fixed blade 13 described later constitute a yarn cutter 14. The slider 4 is connected to one end of a cam lever 17 via a slide piece 15 horizontally movable in a groove formed in horizontal direction at the side of the weft selection device and a connecting pin 16 inserted into the slide piece 15. The cam lever 17 is substantially L shaped and rotatably supported by the first bracket 6 about a lever shaft 18 at the base end thereof. The cam lever 17 is urged clockwise in Fig. 1 by a drawing spring 19 and is positioned by a contour of a rotatable plate like cam 22 together with cam shaft 21 via a cam ball 20 provided at the central portion of the lever 17. The contour curve line of the cam 22 is determined as illustrated in Fig. 5 relative to the turning angle of the main shaft of the loom. The cam shaft 21 corresponds to a color pattern 1 x 1 in which two yarns are successively picked one after the other according to the first embodiment of the present invention. The cam shaft 21 rotates in synchronous with the main shaft of the loom and the reduction gear ratio of the cam shaft 21 relative to the main shaft of the loom is set to be 1 : 2. The cam lever 17 and the cam 22 constitute the driving means 5. The second bracket 7 is attached to the front end surface and holds the two gripping bodies 2, 3 so that the two gripping bodies 2, 3 are movable up and down toward guide holes 27, 28 of the second bracket 7. The gripping bodies 2, 3 are integrated with guide shafts 23, 24 and confronted vertically with each other with interposing the gripper 11 of the slider 4 at the middle portion thereof. Compressed springs 25, 26 are wound around the guide shafts 23, 24 to urge the gripping bodies 2, 3 toward the gripper 11 so that the gripping bodies 2, 3 always contact the gripper 11 of the middle position. The upper guide shaft 23 is restricted to move downward by a stop ring 29 attached to the upper end thereof and the lower guide shaft 24 is restricted to move upward by a stop ring 30 attached to the lower end thereof. There is attached a yarn guide 32 to the side surface of the second bracket 7, i.e., at the side of the fingers 8a, 8b of the weft selection device. The yarn guide 32 has a yarn introduction slit 33 at the side of a let-off motion of the loom. The yarn guide 32 is attached to the second bracket 7 so that the yarn introduction slit 33 is horizontally flush with the open portion defined between the gripping bodies 2, 3 and the gripper 11 of the slider 4. The second bracket 7 is opened at the front side thereof in the same size as the open end of the first bracket 6 and integrated with the fixed blade bracket 31 at the opend end thereof. The fixed blade bracket 31 has the fixed blade 13 having a V-shaped opening at the inside front portion thereof and attached to the side surface of the bracket 7 at the side of the woven cloth 9. The fixed blade 13 contacts the movable blade 12 so as to bring about the shear forth to affect the weft yarn. The first bracket 6 is positioned, as illustrated in Fig. 6, in the manner that the yarn cutter 14 is close to the selvage of the woven cloth 9 so that the yarn introduction slit 33 is flush with the extension line of the cloth fell of the woven cloth 9. Consequently, the first and the second gripping bodies 2, 3 are movable up and down at the position where they cross the extension line of the cloth fell. The picking apparatus 1 confronts a reed 35 on a slay 34 and the part of the picking apparatus 1 between the yarn guide 32 and the fixed blade bracket 31 confronts the opening of the reed 35. When the cam shaft 21 is rotated while it interlocks with the main shaft of the loom, the cam lever 17 swings in proportion to the contour of the cam 22 to thereby move the slider 4 up and down whereby the gripper 11 of the slider 4 moves up and down between the first and the second gripping bodies 2, 3. The gripping bodies 2, 3 moves up and down against the resilience force of the compressed springs 25, 26 while following the vertical motion of the gripper 11. When the slider 4 is positioned uppermost, the first gripping body 2 keeps contact with the the gripper 11 while there is defined an open portion beween the second gripping body 3 and the gripper 11. When the slider 4 is positioned lowest, the second gripping body 3 keeps contact with the the gripper 11 while there is defined an open portion beween the first gripping body 2 and the gripper 11. When the slider 4 is not brought into contact with one of the gripping bodies 2, 3, the open portion defined therebetween is positioned on the extension line of the cloth fell. When the slider is positioned at middle, the gripper 11 is brought into contact with both the first and the second gripping bodies 2, 3. When the slider 4 moves from the middle position to the uppermost position or to the lowest position, the yarn cutter 14 can cut the weft yarn gripped by the gripper 11 and the first gripping body 2 or by the gripper 11 and the second gripping body 3. The slider 4 is, at the middle position thereof, in the state where the gripper 11 is brought inro contact with the first and the second gripping bodies 2, 3 and two weft yarns 9a, 9b can be gripped therebetween as illustrated in Fig. 6. Figs. 7 (1) to (12) show a series of picking operations of the picking apparatus relative to an crank angle in accordance with the color pattern 1 x 1. Figs. 7 (1) to (12) correspond to operating stages (1) to (12). (1) When the slider 4 is positioned lowest, a weft yarn 9b has been gripped between the gripping body 3 and the gripper 11. The weft yarn 9b has been cut by the yarn cutter 14 and severed from the woven cloth 9. A next picked weft yarn 9a is beaten and guided into the open portion defined between the gripping body 2 and the gripper 11. The guiding operation for the weft yarn 9a is effected by a reed blade adjacent to the opening of the reed 35 or L-shaped yarn guide hook 36 attched to the slay 34 instead of the reed blade so as not to interfere with picking operation. At this time, the weft yarn 9a is still extended to a yarn package 38 and introduced into the yarn introduction slit 33 along the yarng guide 32. (2) After the weft yarn 9a is beaten, the slider 4 returns to the middle position so that the weft yarn 9a is gripped between the gripper 11 and the gripping body 2. At this state, the weft yarn 9a is extended to the woven cloth 9 and the weft yarn 9b is still gripped between the gripper 11 and the gripping body 3. (3) (4) The finger 8b of the weft yarn selection device lowers to select the weft yarn 9b. The rapier 37 holds the weft yarn 9b at the position close to the crank angle 80 o and draws the weft yarn 9b which is kept held and starts the picking operation. It is of course that the fingers 8a, 8b of the weft yarn selection device are selected in accodance with the color pattern 1 x 1. (5) The slider 4 moves uppermost at the position close to the crank angle 165 o . At this time, the yarn cutter 14 cuts the weft yarn 9a at the side of the woven cloth 9. At the same time, there is defined an open portion under the gripper 11 of the slider 4. (6) (7) The weft yarn 9b is guided to the open portion while it is beaten. (8) The slider 4 moves to its middle position after the weft yarn 9b is beaten so that the weft yarn 9a is still gripped between the first gripping body 2 and the gripper 11 and the weft yarn 9b is gripped between the second gripping body 3 and the gripper 11. The weft yarn 9b is still extended to the woven cloth 9. (9) (10) The weft yarn 9a is drawn by the rapier 37 when the finger 8a of the weft yarn selection device is positioned at the position close to the crank angle 80 o , whereby the picking operation is started. (11) (12) The slider 4 moves lowest. The yarn cutter 14 cuts the weft yarn 9b between the movable blade 12 and the fixed blade 13. At this time, an open portion is defined over the gripper 11. Thereafter, the operation returns to (1) at the time near the time when the weft yarn is beaten. In the series of picking operation, the weft yarns 9a, 9b are picked one after the other to form 1 x 1 weaving texture. Second Embodiment (Figs. 8 to 10): A second embodiment of the picking apparatus in a rapier loom according to a second embodiment will be described with reference to Figs. 8 to 10. In the second embodiment, the two color alternate two pick weave (a color pattern 2 x 2) or the two color alternate pick weave (a color pattern 2 x 1) is carried out, namely, one of the at least two weft yarns 9a, 9b is successively picked. The two color alternate two pick weave means that the weft yarn 9a is successively picked two times and then the weft yarn 9b is successively picked two times in one cycle of the picking operation. The yarn cutter 14 is composed of the movable blade 12 fixed to the gripper 11 of the slider 4 and the fixed blade 13 fixed to the fixed blade bracket 31. Figs. 8 (1) to (5) show a series of picking operations according to the second embodiment of the picking apparatus in which each figure shows location of the gripper 11 and the gripping bodies 2, 3 on each operating stage. The slider 4 moves, as illustrated in Figs. 8(1) to 8(5), up and down in five stages by the cam 22 having the contour different from the cam in Fig. 5 at the given timing. Assume that the stages (2) to (4) are a middle position. At the stages of (1) and (5), there is defined an open portion over the griper 11 or lower the gripper 11. During the stage of (2) to (4), the weft yarns 9a, 9b are gripped by the gripper 11 and the first and the second gripping bodies 2, 3. At the stage except the stage (3), any of the weft yarns 9a, 9b can be cut. That is, the weft yarn 9b is cut when the operation moves from the stages (1) to (3) to the stage (4) or (5) and the weft yarn 9a is cut when the operation moves from the stages (5) to (3) to the stage (2) or (1). The positional relation between the opening of the fixed blade 13 and the open portions defined between the gripper 11 and the fist and the second gripping bodies 2, 3 are illustrated in Figs. 8 (1′) and (5′). Inasmuch as the yarn guide surfaces 2′, 3′ of the gripping bodies 2, 3 are curved at the fronts of the gripping bodies 2, 3, the weft yarns 9a, 9b are guided into the open portions with assurance. The yarn introduction slit 33 of the yarn guide 32 has the same size as the opening of the fixed blade 13. Figs. 9 (1) to (17) show a series of picking operations according to a color pattern 2 x 2 in which each figure shows each operating stage. In the color pattern 2 x 2, the reduction gear ratio of the cam shaft 21 relative to the main shaft of the loom is set to be 1 : 4. During the stages (1) to (9), the weft yarn 9b is picked successively two times and beaten. After beaten, the weft yarn yarn 9b is cut at the stages (5) and (11). During the stages (10) to (17), the weft yarn 9a is picked successively two times and beaten and cut at the stages (13) and (3). Figs. 10 (1) to (13) show a series of picking operations in accordance with two color alternate two pick x one pick weave (a color pattern 2 x 1) in which each figure shows location of the gripper 11, the gripping bodies 2, 3 and the weft yarns 9a, 9b on each operating stage. In the color pattern 2 x 1, the reduction gear ratio of the cam shaft 21 relative to the main shaft of the loom is set to be 1 : 3. The two color alternate two pick x one pick weave (the color pattern 2 x 1) means that the weft yarn 9b is successively picked two times then the weft yarn 9a is picked one time in one cycle of the picking operation. In the embodiment as illustrated in Fig. 10, after the weft yarn 9b is picked two times during stages (1) to (5) and (6) to (8), the weft yarn 9a is picked one time during stages (9) to (13) to complete one cycle of picking operation. During the stages (1) to (13), the picking apparatus 1 repeates the operation successively so as to grip the weft yarn yarns 9a, 9b, guide the weft yarns 9a, 9b to the open portions in response to the cutting operation and the beating operation. The picking operation according to the second embodiment differs from the first embodiment in that when one of the weft yarns 9b, e.g. is picked successively two times, the first picked weft yarn 9b is cut by the gripper 11's moving to the stage (2) at crank angle about 30° for next picking while the other weft yarn 9a is gripped. After this, the slider 4 moves to its middle position before the weft yarn 9b is picked at second time. Whereupon, the slider 4 is positioned at its middle position at the stage (3) but may be positioned at the stage of (2) or (4). Third Embodiment (Figs. 11 to 14): A picking apparatus of a rapier loom according to a third embodiment of the present invention will be described with reference to Figs. 11 to 14. The driving means 5 is composed of, as illustrated in Fig. 11, first and second solenoids 41, 42 and the like. The yarn cutter 14 is, as illustrated in Fig. 12, provided separately from the picking apparatus 1 whereby the weft yarns can be picked in accordance with two color free pick weave (a color pattern AT WILL), namely, the weft yarns 9a, 9b can be picked at will. The yarn cutter 14 is disposed at the portion adjacent to the woven cloth 9 and opposed to the picking apparatus 1. The yarn cutter 14 is connected to a driving portion 39 so as to cut the weft yarn one time before the weft yarn is picked, i.e. during the period after the beating operation and before the picking operation. The slider 4 is in its middle position at the start of the picking opeation to grip both the weft yarns 9a, 9b and moves uppermost or lowest at the beating operation to thereby form the open portion for receiving the picked weft yarn 9a or 9b. For example, the slider 4 is set to be positioned at its middle position at cranks angle between 6 o to 126 o . The slider 4 is positioned at the upper or the lower position except that period mentioned just above so that the slider 4 is ready for receiving the weft yarns 9a or 9b to be beaten. The yarn cutter 14 operates at crank angle about 30 o to cut any of the weft yarns 9a or 9b. As illustrated in Fig. 11, the solenoids 41, 42 are connected to the lever 40 at the distal ends of the rods thereof. A connecting pin 16 is fixed on the lever 40 at the position displaced from the center of the lever 40. Positions 1, 2, 3 of the connecting pin 16 as illustrated in Fig. 11 correspond to positions 1, 2, 3 of the gripper 11 of the slider 4. The slider 4 can move to three stages as illustrated in Fig. 13 on the basis of the on or off control of the two solenoids 41, 42. When the two color free pick weave is effected according to a color pattern such as 9a→9b→9a→9b→9b as illustrated in Fig. 14, output patterns of switching signals K1 to K3 is previously input and stored in a switching signal output circuit 43. The switching signal output circuit 43 receives a crank angle signal during weaving operation from an encoder connected to a main shaft 44 of the loom and provides the corresponding switching signals successively to an on-off control circuit 46 during the output period of the switching signals. The on-off control circuit 46 selectively turns on or off the solenoid 41 or 42 in response to the switching signals K1 to K3 to thereby place the the lever 40 horizontally or incline the lever 40 in any direction so that the hight of the connecting pin 16 is adjusted to three stages. Fourth Embodiment (Figs. 15 to 16): A picking apparatus of a rapier loom according to a fourth embodiment will be described with reference to Figs. 15 and 16. In the fourth embodiment, the slider 4 is electrically and directly driven so that the weft yarns 9a, 9b can be picked at will. in accodance with the two color free pick weave. The switching output circuit 43 operates in the same way as that of the third embodiment. A switching circuit 48 in a rotation control circuit 47 receives driving signals S1 to S3 corresponding to the switching signals K1 to K3 from a setting circuit 49 upon reception of the switching signals K1 to K3 from the switching signal output circuit 43 and provides the driving signals S1 to S3 to a driving circuit 50. The drivng cirucit 50 drives a pulse motor 51 which moves the slider 4 up and down in correspondence with the three positions 1, 2 or 3 as illustrated in Fig. 12. The rotary motion of the pulse motor 51 is changed to the vertical motion of the connecting pin 16 of a slider 54 along a rail 55 by a rack 52 and a pinion 53. Modified Embodiment (Fig. 17): The picking apparatuses of the rapier loom according to the first to fourth embodiments set forth above relate to the two-color yarns but may be utilized for the four-color weft yarns. In case of picking operation of four-color weft yarns, two picking apparatuses are disposed in two stages at upper and lower positions and the two picking apparatuses per se are moved up and down in response to the selected weft yarn so that the picking apparatuses are positioned for picking operation. It is a matter of course that the driving means for driving the apparatuses comprises the cam, the lever mechanism and the rotation control device of the motor as employed in the first to fourth embodiments. In each picking apparatus, the open portions defined between the gripper 11 and the first and the second gripping bodies 2, 3 are positioned at the extension line of the cloth fell so that each picking apparatus can carry out the necessary operation. Although the gripping bodies 2, 3 are movable linearly up and down according to the first to the fourth embodiments, the gripping bodies may be movable circularly up and down. For example, the gripping bodies 2, 3 may be provided at the distal ends of the two levers which swing about one point. It is preferable that the gripper 11 of the slider 4 and the gripping bodies 2, 3 are positioned to cross the extension line of the cloth fell at the gripping surfaces thereof to minimize the loss of the weft yarn. However, the gripping surfaces of the grippe 11 of the slider 4 and the gripping bodies 2, 3 may be positioned slightly closer to the winding side or the let off side than the extension line of the cloth fell. When the gripping surfaces are positioned close to the winding side, a yarn pusher 36 is provided at the slay 34 so that the weft yarn end is forcibly guided to the open portion defined between the gripper and the girpping bodes 2, 3. The yarn introduction slit 33 of the yarn guide 32 may form a hook shaped groove 33a as illustrated in Fig. 17 so that the weft yarn 9a or 9b enters the groove 33a when they are gripped. When the weft yarn 9a or 9b enters the groove 33a, the weft yarn 9a or ob can not slip out thereof even if the forward force is applied thereto so that the weft yarn 9a or 9b is gripped and cut with assuracne.

Claims: A picking apparatus (1) in a rapier loom comprising a yarn cutter (14) operative to cut a weft yarn (9a or 9b) before the weft yarn (9a or 9b) is picked, a slider (4) and driving means (5), characterized in that first and second opposed gripping bodies (2, 3) are respectively disposed between first and second fingers (8a, 8b) of a weft yarn selection device and a yarn cutter (14), the first and the second gripping bodies (2, 3) movable up and down and urged in the direction of the middle position thereof to confront with each other; the slider has a gripper (11) movable up and down between the first and the second gripping bodies (2, 3), the gripper (11) being capable of contacting both the first and the second gripping bodies (2, 3) when positioned at the middle position between the first and the second gripping bodies (2, 3), and capable of contacting one of the gripping bodies (2, 3) so that an open portion is defined between the gripper (11) of the slider (4) and the other gripping body (3 or 2) when positioned at one of the gripping bodies (2, 3); and said driving means (5) are capable of moving the slider (4) toward one of the gripping bodies (2 or 3) in accordance with a color pattern at the beating operation of the weft yarns (9a, 9b) and capable of moving the slider (4) at the middle position between the first and the second gripping bodies (2, 3) at start of the picking operation of the weft yarn (9a, 9b). A picking apparatus (1) of a rapier loom according to claim 1, wherein the yarn cutter (14) comprises a movable blade (12) provided at the side surface of the slider (4) and a fixed blade (13) provided at a fixed blade bracket (31) for holding the gripping bodies (2, 3). A picking apparatus (1) of a rapier loom according to claim 1, further comprising a yarn guide (32) provided at the side of the first and the second gripping bodies (2, 3), the yarn guide (32) having a yarn introduction slit (33) positioned adjacent to the gripper (11) of the slider (4). A picking apparatus (1) of a rapier loom according to claim 1, wherein the driving means (5) comprises a cam (22) which drives the slider (4) and which is rotatable in synchronism with a rotary motion of the rapier loom and a lever (17) capable of moving the slider (4) up and down. A picking apparatus (1) of a rapier loom according to claim 1, wherein the driving means (5) comprises a switching signal generating circuit (43) for generating switching signals in synchronism with a rotation of a main shaft (44) of the rapier loom, first and second solenoids (41, 42) which are driven on the reception of the switching signals, and a lever (40) having both ends each connected to the first and the second solenoids (41, 42) and capable of interlocking with the slider (4) between both ends. A picking apparatus (1) of a rapier loom according to claim 1, wherein the driving means (5) comprises a switching signal generating circuit (43) for generating switching signals in synchronism with a rotation of a main shaft (44) of the rapier loom, a pulse motor (51) which are driven upon reception of the switching signals, and a rack (52) and a pinion (53) which are respectively reciprocally moved by the pulse motor (51). A picking apparatus (1) of a rapier loom according to claim 1, wherein the first and the second gripping bodies (2, 3), the slider (4) and the driving means (5) are disposed in several stages in response to the picking of the even number of two or more color wefts.

Inventors: KASAHARA JUNYA, KASAHARA, JUNYA
Applicants: TSUDAKOMA IND CO LTD, TSUDAKOMA CORP.
Application year: 1990
Main classification: D03D49
IPC codes: D03D47, D03D49