JP2005087510A - Looper driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a looper driving device which moves a looper smoothly by synchronizing a looper shaft with vertical movements of a needle even at a high-speed rotation of a main shaft without generating a noise and jouncing movements of the looper shaft during an operation of a sewing machine. <P>SOLUTION: The looper driving device is equipped with the looper shaft 11, which is disposed in the direction perpendicular to the direction of the vertical movements of the needle, has the center of the shaft in the direction for feeding an article to be sewn, and is provided throughout a sewing machine bed and a cylinder bed, and the looper 13 provided at the end of the looper shaft 11 through a looper base 12, oscillates the looper shaft 11 around the center of the shaft while synchronizing the looper shaft 11 with the needle making vertical movements by the rotations of a main shaft 15, and moves back and forth in the direction of the center of the shaft. The looper shaft 11 has the single center of the shaft throughout the length, and a looper oscillating arm 20 for oscillating the looper shaft 11 and a pair of looper shaft collars 26 which keep a looper back and front arm 24 for moving the looper shaft 11 back and forth between the looper shaft collars 26 from the back and front are connected with the looper shaft 11 in the sewing machine head. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a looper driving device for a cylindrical bed sewing machine that is suitably used for sewing work such as a tubular article to be sewn, such as a shirt sleeve and neck, a leg portion of a trouser, and the like.

  In general, a sewing machine for sewing a cylindrical sewing product, specifically, a flat stitch sewing machine or a double chain stitch sewing machine, has a needle drop position at the lower side of a needle plate that is a feeding surface of the sewing product. The advancing operation along the back side and the retreating operation along the front side of the needle drop position are performed in synchronization with the vertical movement of the needle, and the needle thread loop formed on the back side of the needle that moves up during the advancing is captured. While pulling out, the looper thread loop formed on the back side of itself and the needle moving downward between each needle thread is caught, and the seam with the needle thread and the looper thread rubbed on the back of the workpiece To form. That is, the looper moves along an elliptical trajectory having a predetermined width centered on the needle drop position, with the major axis in the direction substantially orthogonal to the feed direction of the sewing product in a plane substantially orthogonal to the vertical movement of the needle. It is like that.

  Sewing machines equipped with such a looper are described in Patent Document 1 and Patent Document 2, for example.

  First, such a sewing machine 100 will be described with reference to FIGS.

  The sewing machine 100 includes a sewing machine bed 102, a sewing machine arm 103 that extends laterally from the upper end of the sewing machine bed 102, and a lower part of the sewing machine arm 103 that extends from the sewing machine bed 102 in parallel with the sewing machine arm 103. The needle bar 106 provided with the needle 105 is provided at the tip of the sewing machine arm 103 so as to be movable up and down, and the presser shaft 108 provided with the presser 107 adjusts the presser pressure in the vertical direction. It is provided freely. A needle plate 109 is fixed to the tip of the cylinder bed 104 with a screw (not shown) corresponding to the needle 105 and the presser 107, and a cylinder cover 110 is detachably provided. Further, the cylinder bed 104 is provided with a looper shaft 111 between the sewing machine bed 102 and the cylinder bed 104, and although not shown in detail, the workpiece to be sewn is fed in the slit of the needle plate 109. A feed mechanism that feeds in the root direction of the cylinder bed 104 (in the direction of the arrow in FIG. 7) by teeth is also provided in parallel with the looper shaft 111.

  On the other hand, on the inner side of the cylinder cover 110, the tip of the looper shaft 111 protrudes through the tip of the cylinder bed 104, and the looper base 112 and the looper base 112 connected to the tip of the looper shaft 111 are provided. A looper 113 is disposed.

  In addition, a main shaft (not shown) connected to the pulley 114 is rotatably supported on the sewing machine bed 102, and the pulley 114 and the main shaft rotate via an electric motor and a belt (not shown). Torque is transmitted to the looper shaft 111 via a looper drive mechanism (not shown) housed in the sewing machine bed 102, and the looper 113 swings around the looper shaft 111 and moves back and forth along the looper shaft 111. It is something to be made. At this time, since the needle 105 moves up and down due to the rotation of the main shaft, the looper 113 eventually moves on an elliptical orbit by swinging around the needle drop position and moving back and forth in synchronization with the vertical movement of the needle 105. To do.

As shown in FIG. 9, the looper shaft 111 is formed of a shaft main body 111a and a U-shaped connecting member 111b integrally connected to the base end of the shaft main body 111a. The shaft 111a is transmitted through the member 111b.
Republic of China Exclusive Notification No. 158836 Republic of China exclusive notification No. 465596

  By the way, in the cylindrical bed sewing machine described above, the main shaft rotates about 3500 per minute, but further, high-speed rotation of 4500 rotations or more per minute is required. When performing such high-speed rotation, in the above-described looper drive mechanism, the looper shaft is formed of the shaft body and the U-shaped connecting member, and the rotational torque of the main shaft is transmitted via the U-shaped connecting member. Is transmitted to the shaft body. At this time, the U-shaped connecting member is slightly bent or twisted, which is unsuitable for high-speed rotation, such as generation of noise during operation of the sewing machine and occurrence of rattling of the looper shaft.

  Further, the forward and backward movement of the looper shaft is increased by the bending and deformation of the U-shaped connecting member, and therefore the elliptical motion of the looper swells in the front-rear direction. As a result, a delicate intersection gap at the time of intersection between the needle and the looper becomes large, and there is a possibility that skipping occurs.

  The present invention has been made in view of such problems, and is synchronized with the vertical movement of the needle without generating noise or shaking of the looper shaft even when the main shaft rotates at high speed. Thus, a looper driving device capable of smoothly operating the looper is provided.

  The present invention provides a looper shaft that is substantially orthogonal to the vertical movement direction of the needle and has an axis in the feed direction of the sewing product, and is provided across the sewing machine bed and the cylinder bed, and a looper base at the tip of the looper shaft. A looper drive device, wherein the looper shaft swings about an axis in synchronization with a needle that moves up and down by rotation of the main shaft, and moves forward and backward in the axial direction. The shaft has a single axis over the entire length, and a looper swing arm that swings the looper shaft is connected to the looper shaft in the sewing machine bed, and the looper front and rear arms that move the looper shaft back and forth in the front-rear direction. A pair of looper shaft collars to be sandwiched are connected.

  According to the present invention, the needle is moved up and down by rotating the main shaft, while the looper shaft is swung around the axis through the looper swinging arm in synchronization with the vertical movement of the needle, and the looper front and rear arms And it is advanced and retracted in the axial direction through the looper shaft collar. Accordingly, the looper is moved along an elliptical trajectory having a predetermined width centered on the needle drop position with the long axis in the direction substantially perpendicular to the feed direction of the sewing product in a plane substantially perpendicular to the vertical movement of the needle.

  Here, the looper shaft has a single axial center over the entire length, a looper swinging arm that swings the looper shaft is connected to the looper shaft in the sewing machine bed, and a looper that moves the looper shaft forward and backward. By connecting the pair of collars that sandwich the front and rear arms from the front and rear, the looper shaft can be swung and the shaft can be moved back and forth smoothly as the main shaft rotates.

  As a result, even when the main shaft rotates at high speed, the looper can be operated smoothly in synchronism with the vertical movement of the needle without generating noise or rattling of the looper shaft. Further, the forward / backward movement of the looper shaft is not increased by the bending and deformation of the U-shaped connecting member, and the elliptical motion of the looper does not swell in the front / rear direction. As a result, it is possible to prevent the occurrence of skipping without increasing the delicate gap between the needle and the looper.

  In the present invention, when a square piece abutting on the looper shaft collar is rotatably supported on the looper front and rear arms, the square piece always comes into surface contact with the looper shaft collar when the looper front and rear arms swing. The swinging motion of the front and rear arms of the looper can be reliably transmitted to the looper shaft collar, that is, the looper shaft.

  According to the present invention, even when the main shaft rotates at a high speed, the looper can be smoothly operated in synchronism with the vertical movement of the needle without generating noise or shaking the looper shaft during sewing operation. . In addition, the occurrence of skipping can be prevented and the durability of the looper shaft can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a cylindrical bed sewing machine 1 provided with the looper driving device of the present invention.

  As described above, the sewing machine 1 also includes the sewing machine bed 2, the sewing machine arm 3 extending laterally from the upper end of the sewing machine bed 2, and the sewing machine bed 2 positioned below the sewing machine arm 3 from the sewing machine bed 2. A cylinder bed 4 extending in parallel with the arm 3, and a needle bar 6 provided with a needle 5 is provided at the tip of the sewing machine arm 3 so as to be movable up and down, and a pressing shaft provided with a presser 7. 8 is provided so that the presser pressure can be adjusted in the vertical direction. A needle plate 9 is fixed to the tip of the cylinder bed 4 with a screw (not shown) corresponding to the needle 5 and the presser 7, and a cylinder cover 10 is detachably provided. Further, the cylinder bed 4 is provided with a looper shaft 11 (see FIG. 2) over the sewing machine bed 2, and although not shown in detail, an article to be sewn is interposed in the slit of the needle plate 9. A feed mechanism that feeds the cylinder bed 4 in the root direction (in the direction of the arrow in FIG. 1) by using the feed dog is also provided in parallel with the looper shaft 11.

  Inside the cylinder cover 10, the tip of the looper shaft 11 protrudes through the tip of the cylinder bed 4, and is provided on the looper base 12 and the looper base 12 connected to the tip of the looper shaft 11. A looper 13 is provided (see FIG. 2).

  Further, a main shaft 15 (see FIG. 2) to which the pulley 14 is connected is rotatably supported on the sewing bed 2, and rotational torque is applied to the pulley 14, that is, the main shaft 15 via an electric motor and a belt (not shown). Can be transmitted.

  Here, the directions of the looper shaft 11 and the main shaft 15 are orthogonal to each other.

  As shown in detail in FIGS. 2 and 3, a looper swinging eccentric ring 16 is screwed to the main shaft 15 in the sewing machine bed 2. A looper swinging member 17 is rotatably inserted into the looper swinging eccentric ring 16, and a looper swinging joint 19 is rotatably supported at the tip of the looper swinging member 17 via a connecting pin 18. Has been. Further, a looper swing arm 20 having a ball 20a is screwed to the looper shaft 11 in the sewing machine bed 2, and the ball 20a of the looper swing arm 20 forms a ball joint on the aforementioned looper swing joint 19. It is connected.

  Therefore, when the main shaft 15 rotates, the looper swinging member 17 fitted and inserted into the looper swinging eccentric ring 16 that rotates integrally with the main shaft 15 is used as an eccentric distance between the axis of the looper swinging eccentric ring 16 and the shaft center of the main shaft 15. Up and down in the vertical direction over twice the distance. When the looper swinging member 17 is moved up and down, the looper swing joint 19 is lifted and lowered, and the looper swing arm 20 is lifted and lowered via the looper swing joint 19. It can be swung around its axis.

  Further, a looper front / rear eccentric ring 21 is screwed to the main shaft 15 at a distance from the looper swing eccentric ring 16 in the axial direction in the sewing machine bed 2. A looper front / rear member 22 is rotatably inserted into the looper front / rear eccentric ring 21, and a looper front / rear arm 24 is connected to the tip of the looper front / rear member 22 via a connecting pin 23. That is, the other end portion of the connecting pin 23 rotatably supported by the looper front / rear member 22 is inserted into the elongated hole 24a of the looper front / rear arm 24, and a nut is screwed to the connecting pin 23, thereby the looper front / rear arm. The dropout of 24 is prevented. Further, a looper front / rear shaft 25 is rotatably supported on the sewing machine bed 2, and the looper front / rear arm 24 described above is rotatably inserted into the looper front / rear shaft 25. Further, a looper shaft collar 26 with which the operating portion 24b of the looper front / rear arm 24 can abut in the sewing machine bed 2 is fitted into the looper shaft 11 and screwed.

  In order to prevent the looper front / rear arm 24 from falling off from the looper front / rear shaft 25, the looper front / rear shaft collar 25 sandwiches the looper front / rear arm 24 positioned with respect to the looper front / rear shaft 25 from the left and right. 27 is inserted and screwed.

  Therefore, when the main shaft 15 rotates, the looper front / rear member 22 inserted into the looper front / rear eccentric ring 21 that rotates integrally with the main shaft 15 is displaced by the eccentric distance between the axis of the looper front / rear eccentric ring 21 and the axis of the main shaft 15. It is advanced and retracted in the front-rear direction over twice the distance. Then, when the looper front / rear member 22 is advanced and retracted, the looper front / rear arm 24 swings around the looper front / rear shaft 25 and the operating portion 24b pushes the looper shaft collar 26 connected to the looper shaft 11. Eventually, the looper shaft 11 can be advanced and retracted in the axial direction over the swing range of the looper front and rear arm 24.

  Here, the connecting pin 18 pivotally supported by the looper swinging member 17 and the connecting pin 23 pivotally supported by the looper front and rear member 22 are orthogonal to each other. Further, the looper shaft 11 and the connecting pin 18 pivotally supported by the looper swing member 17 are parallel to each other.

  On the other hand, as shown in FIG. 2, the looper shaft 11 is formed of a torque shaft having a single axis over its entire length, and supports the looper shaft 11 in the vicinity of the front end portion, the middle portion and the rear end portion thereof. Bushing 28 (three places in total) is provided.

  Next, the operation of the thus configured looper driving device will be described.

  When the rotational power is transmitted to the pulley 14 via an electric motor and a belt (not shown), the main shaft 15 rotates to move the needle 5 up and down, and at the same time, a looper swing connected to the main shaft 15 in the sewing machine bed 2. The eccentric ring 16 and the looper front / rear eccentric ring 21 are respectively rotated so that the looper swing member 17 fitted in the looper swing eccentric ring 16 has an eccentric distance of 2 between the axis of the looper swing eccentric ring 16 and the axis of the main shaft 15. The looper front / rear member 22 inserted into the looper front / rear eccentric ring 21 is moved up and down over a double distance, and is twice the eccentric distance between the axis of the looper front / rear eccentric ring 21 and the axis of the main shaft 15. Advancing in the front-rear direction.

  The raising and lowering of the looper swing member 17 raises and lowers the looper swing joint 19 connected to the looper swing member 17 and simultaneously lifts and lowers the looper swing arm 20 connected to the looper swing joint 19. In this case, since the looper swing arm 20 is integrally connected to the looper shaft 11, the looper shaft 11 can be swung about its axis over the range in which the looper swing arm 20 moves up and down.

  Further, the forward / backward movement of the looper front / rear member 22 causes the looper front / rear arm 24 connected to the looper front / rear member 22 to swing around the looper front / rear shaft 25, so that the operating portion 24 b pushes the looper shaft collar 26. In this case, since the looper shaft collar 26 is integrally connected to the looper shaft 11, the looper shaft 11 can be advanced and retracted in the axial direction over the swinging range of the operating portion 24 a of the looper front and rear arm 24.

  Thus, when the main shaft 15 rotates, the rotational torque is transmitted to the looper shaft 11, and the looper shaft 11 is swung around the axis and moved back and forth in the axial direction. Therefore, the looper 13 provided at the tip of the looper shaft 11 via the looper base 12 swings around the looper shaft 11, moves back and forth along the looper shaft 11, and synchronizes with the vertical movement of the needle 5. Then, it moves on an elliptical orbit by swinging around the needle drop position and moving back and forth.

  Here, since the looper shaft 11 has a single axis over the entire length, the swinging motion of the looper shaft 11 by the looper swing arm 20 and the forward / backward motion of the looper shaft 11 by the looper front / rear arm 24 are noise. Is performed smoothly without causing the looper shaft 11 to rattle.

  As a result, even when the main shaft 15 is rotated at a high speed, the looper 13 can be smoothly operated in synchronism with the vertical movement of the needle 5 without generating noise or rattling of the looper shaft 11. .

  Further, the forward / backward movement of the looper shaft is not increased by the bending and deformation of the U-shaped connecting member, and the elliptical motion of the looper does not swell in the front / rear direction. As a result, it is possible to prevent the occurrence of skipping without increasing the delicate gap between the needle and the looper.

  In the above-described embodiment, the operating portion 24 b of the looper front / rear arm 24 is directly brought into contact with the looper shaft collar 26 connected to the looper shaft 11, and the swinging motion of the looper front / rear arm 24 is moved forward and backward. 5 and 6, as shown in FIGS. 5 and 6, the square piece 30 is pivotally supported via the square piece pin 29 on the operating portion 24b of the looper front and rear arm 24 so that the square piece 30 is You may make it contact | abut to the looper axis | shaft collar 26. FIG.

  When such a square piece 30 is employed, the square piece 30 can always be brought into surface contact with the looper shaft collar 26 during the swinging movement of the looper front / rear arm 24, so that the swinging movement of the looper front / rear arm 24 is ensured. It can be transmitted to the looper shaft 11 via the looper shaft collar 26.

  As described above, according to the present invention, even when the main shaft rotates at high speed, the looper can be smoothly moved in synchronism with the vertical movement of the needle without generating noise during the operation of the sewing machine or rattling of the looper shaft. Since it can be operated, it is possible to provide a cylindrical bed sewing machine with high working efficiency by rotating the main shaft at a high speed.

It is a perspective view which shows the cylindrical bed sewing machine provided with the looper drive device of this invention. It is a perspective view of the looper drive device of FIG. It is a disassembled perspective view of the looper drive device of FIG. It is a side view which abbreviate | omits and shows a part of looper drive device of FIG. It is a disassembled perspective view which abbreviate | omits and partially shows other embodiment of a looper drive device. It is a side view which shows the looper drive device of FIG. It is a perspective view which shows an example of the conventional cylindrical bed sewing machine. It is sectional drawing of the cylinder bed of FIG. It is a disassembled perspective view which abbreviate | omits and shows a part of looper drive device of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical bed sewing machine 2 Sewing machine bed 3 Sewing machine arm 4 Cylinder bed 5 Needle 7 Presser 11 Looper shaft 13 Looper 15 Main shaft 16 Looper swing eccentric ring 17 Looper swing member 19 Looper swing joint 20 Looper swing arm
21 Looper front / rear eccentric ring 22 Looper front / rear member 24 Looper front / rear arm 26 Looper shaft collar 30 Square piece

Claims (2)

  A looper shaft that is substantially perpendicular to the vertical movement direction of the needle and has an axis in the feed direction of the sewing product, and is provided across the machine bed and the cylinder bed, and is provided at the tip of the looper shaft via a looper base. In the looper drive device, wherein the looper shaft is swung around the axis in synchronism with a needle that moves up and down by the rotation of the main shaft, and moves forward and backward in the axial direction. A pair of loopers having a single shaft center and having a looper swinging arm for swinging the looper shaft connected to the looper shaft in the sewing machine bed and sandwiching the looper front and rear arms for moving the looper shaft back and forth in the front-rear direction A looper drive device characterized in that the shaft collar is connected. 2. The looper driving device according to claim 1, wherein a square piece abutting on a looper shaft collar is rotatably supported on the front and rear arms of the looper.

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