Abstract: An articulated arm having a first arm member and a second arm member flexibly coupled mutually by a ball joint. From a plurality of through-holes provided in the first arm member 2 to a plurality of holding holes provided in the second arm member, compression coil springs 8 are inserted. Support shafts are inserted, movably back and forth freely, in the through-holes behind the rear end portion of the compression coil springs. A certain support shaft is moved forward by actuator or the like to push the compression coil spring while other support shaft are moved backward. As a result, the second arm member can be moved to a specified position by the ball joint. Stopping state of the second arm member at the specified position is maintained by the balance of position of support shaft and repulsive force of compression coil spring.

Abstract: A sheet package body P has a first package body 1 and a second package body 2. The first package body 1 is disposed on the second package body 2 by overlapping in part, said overlapped portion L is set in a double chain stitch sewing machine and is sewn. A stitching D of chain stitch is formed said portion L. By pulling the sewing end portion 4a of the looper thread 4 forming the stitching D of chain stitch, the stitching D of chain stitch gradually unravels from the sewing end portion, and the both package bodies 1, 2 are separated from each other.

Abstract: The invention comprises a first arm member 2 and a second arm member 3 flexibly coupled mutually by a ball joint 4. From a plurality of through-holes 5 provided in the first arm member 2 to a plurality of holding holes 6 provided in the second arm member 3, compression coil springs 8 are inserted. Support shafts 10 are inserted, movably back and forth freely, in the through-holes 5 behind the rear end portion of the compression coil springs 8. A certain support shaft 10 is moved forward by actuator or the like to push the compression coil spring 8 while other support shaft 10 are moved backward. As a result, the second arm member 3 can be moved to a specified position by the ball joint 4. Stopping state of the second arm member 3 at the specified position is maintained by the balance of position of support shaft 10 and repulsive force of compression coil spring 8.

Abstract: A sheet package body P has a first package body 1 and a second package body 2. The first package body 1 is disposed on the second package body 2 by overlapping in part, said overlapped portion L is set in a double chain stitch sewing machine and is sewn. A stitching D of chain stitch is formed said portion L. By pulling the sewing end portion 4a of the looper thread 4 forming the stitching D of chain stitch, the stitching D of chain stitch gradually unravels from the sewing end portion, and the both package bodies 1, 2 are separated from each other.

Abstract: In an upper looper holder guide 7 through which an upper looper holder 12 penetrates, a first oil discharge hole 27 is opened in the edge at the upper end of a through-hole 11 and a second oil discharge hole 28 opened in the groove 26 and are branched off, the opening of the first oil discharge hole 27 contacts with the upper looper holder 12, and the opening of the second oil discharge hole 28 and groove 26 are exposed from a longitudinal hole 6 of an upper looper base 4 when the upper looper holder 12 reaches the top dead center or the bottom dead center. The oil discharge device is composed of a two-layer trochoid pump.

Abstract: A push-up lever is rotatably supported on a sewing machine frame, and a coupling lever is coupled to the push-up lever. An oscillating shaft is rotatably supported on a bush, and the coupling lever is engaged with a part of the oscillating shaft. A presser base is coupled to a crank piece of the oscillating shaft, and a presser foot is fixed at its leading end. An elastic member engaged with the presser base. A bracket changeable in fixing position is supported on the back side of the sewing machine frame, and the bush is fixed in the bracket. The crank piece of the oscillating shaft is separable in two pieces, and the engaging faces of the two separated crank pieces are fixed anew when changing the fixing position of the bracket. Therefore, the circular track of the presser foot near the platform of the sewing machine bed can be changed easily, and an eccentric portion of the crank piece is not changed from an initial setting position.

Abstract: A main needle holder is disposed above a needle plate, and has a screw portion for fitting a needle bar. A sub needle holder is fitted to the main needle holder by a set screw so as to be adjustable in position. Fitting position of the sub needle holder to the main needle holder is changed when loosening the screw, so that the interval of the plural needle is widened or narrowed in the longitudinal direction. Plural needles are individually fitted to the needle holders, and penetrate through a needle hole of the needle plate when descending. The fitting position of the sub needle holder to the main needle holder is changed by a longitudinal slit formed linearly on the main needle holder, and the cloth penetration lines by at least two needles of plural needles can be mutually set along in a narrow width.

Abstract: A main needle holder is disposed above a needle plate, and has a screw portion for fitting a needle bar. A sub needle holder is fitted to the main needle holder by a set screw so as to be adjustable in position. Fitting position of the sub needle holder to the main needle holder is changed when loosening the screw, so that the interval of the plural needle is widened or narrowed in the longitudinal direction. Plural needles are individually fitted to the needle holders, and penetrate through a needle hole of the needle plate when descending. The fitting position of the sub needle holder to the main needle holder is changed by a longitudinal slit formed linearly on the main needle holder, and the cloth penetration lines by at least two needles of plural needles can be mutually set along in a narrow width.

Abstract: A push-up lever is rotatably supported on a sewing machine frame, and a coupling lever is coupled to the push-up lever. An oscillating shaft is rotatably supported on a bush, and the coupling lever is engaged with a part of the oscillating shaft. A presser base is coupled to a crank piece of the oscillating shaft, and a presser foot is fixed at its leading end. An elastic member engaged with the presser base. A bracket changeable in fixing position is supported on the back side of the sewing machine frame, and the bush is fixed in the bracket. The crank piece of the oscillating shaft is separable in two pieces, and the engaging faces of the two separated crank pieces are fixed anew when changing the fixing position of the bracket. Therefore, the circular track of the presser foot near the platform of the sewing machine bed can be changed easily, and an eccentric portion of the crank piece is not changed from an initial setting position.

Abstract: A thread taking-up tool is attached to a needle bar sticking out of a sewing machine head, and its leading end has a plurality of thread holes. The thread holes of the thread taking-up tool are arranged in the lateral direction. A thread handling body has a cam face in the vertical direction. Needle threads from a tension device to needles are controlled by the vertical motion of the thread taking-up tool and the action of the cam face of the thread handling body. When the needles ascend from the lowest position, an endless hook attached to the thread taking-up tool is engaged with the left needle thread between the cam face lower end and the thread hole of the thread taking-up tool. Each thread is handled in with the left needle thread staying at the cam face lower end, so that the needle thread loop at the remotest end is absorbed surely.

Abstract: A fabric guide device for a sewing machine has an upper plate and a middle plate, and is disposed at the fabric feed side of the presser foot of the sewing machine. The upper plate is disposed on the sewing machine bed in a state of keeping a certain clearance from the sewing machine bed, and its fabric feed side portion is warped upward. The middle plate is disposed beneath said warped portion of the upper plate, and is free to project and retreat from and into the sewing machine bed. The middle plate has upper and lower surfaces for guiding the upper and lower bodies. When sewing said bodies together, first the middle plate projects from the sewing machine bed to insert between the bodies. Then the bodies are pulled forward, and the over-edge chain stitching portions are engaged with the middle plate to be tilted to the fabric feed side.

Abstract: A two-needle overlock sewing machine comprises a throat plate and a middle tongue. The throat plate has an opening needle hole and an outer tongue. The middle tongue is disposed parallel to the outer tongue, a thread chain is formed so as to envelop both tongues. The presser foot is disposed so as to press the cloth to the throat plate by a spring. A push-up lever lifts up the presser foot by handling. The push-up lever and the middle tongue are coupled together by a transmission mechanism. By raising the presser foot by manipulation of the push-up lever at the finish of sewing operation, the middle tongue draws back simultaneously and retreats from the needle hole. As a result, the manipulation for drawing back the middle tongue during the process of thread chain handling is not needed, and the operation is simplified.

Abstract: A pair of tension discs is disposed on a tension stud fixed in part of a sewing machine main body. A pneumatic cylinder has a drive rod. The drive rod moves at least one of the tension discs to other tension disc so that one tension disc is pressed to other tension disc. An air regulator is interposed between the pneumatic cylinder and an air supply source, being composed in an electropneumatic system for converting between voltage and air pressure. By controlling the applied voltage to the electropneumatic air regulator on the basis of an instruction from a microcomputer, the set pressure of the air supplied to the pneumatic cylinder is adjusted. Thereby the pressure to the thread held between the pair of tension discs, that is, the thread tension is controlled. As a result, without having to stop the operation of the sewing machine, the thread tension can be adjusted promptly and appropriately.

Abstract: A pair of tension discs is disposed on a tension stud fixed in part of a sewing machine main body. A pneumatic cylinder has a drive rod. The drive rod moves at least one of the tension discs to other tension disc so that one tension disc is pressed to other tension disc. An air regulator is interposed between the pneumatic cylinder and an air supply source, being composed in an electropneumatic system for converting between voltage and air pressure. By controlling the applied voltage to the electropneumatic air regulator on the basis of an instruction from a microcomputer, the set pressure of the air supplied to the pneumatic cylinder is adjusted. Thereby the pressure to the thread held between the pair of tension discs, that is, the thread tension is controlled. As a result, without having to stop the operation of the sewing machine, the thread tension can be adjusted promptly and appropriately.

Abstract: In a double chainstitch sewing machine, a movable thread guide 37 is fixed to the lower end of a needle bar 1. A fixed thread guide 41 and a thread take-up cam 39 are fixed to a jaw 43a of a sewing machine arm 43. The thread take-up cam 39 has a cam section to be engaged with needle threads 51a, 51b from the fixed thread guide 41 to the movable thread guide 37, and takes up the needle threads oscillating up and down by vertical motion of the movable thread guide 37. Thread take-up members such as movable thread guide 37, fixed thread guide 41, and thread take-up cam 39 are disposed centrally at the lower end of the needle bar near the needle and in the jaw 43a of the sewing machine arm 43. As a result, there is no member for thread take-up moving at the upper side and front side of the sewing machine arm, and dangerous positions for the operator can be decreased.

Abstract: A sewing machine related to the present invention comprises a needle plate and feed dogs. A second feed dog slot provided at the cloth send-in side of a portal shaped needle hole of the needle plate is shifted to the right side from the center of the portal shaped needle hole. The left side first feed dog slot is extending toward the second feed dog slot side in the cloth send-in side of the portal shaped needle hole, so as to be formed a wide breadth portion from side to side. A first cross-piece of the needle plate is disposed between the wide breadth portion and a needle drop portion of the portal shaped needle hole, and a second cross-piece of the needle plate is disposed between the second feed dog slot and said needle drop portion. The first cross-piece is formed wider in the cloth feed direction than the second cross-piece. A differential feed dog disposed in the cloth send-in side of the needle drop portion is composed in a shape combining each feed dog slots.

Abstract: A sewing machine related to the present invention comprises a needle plate and feed dogs. A second feed dog slot provided at the cloth send-in side of a portal shaped needle hole of the needle plate is shifted to the right side from the center of the portal shaped needle hole. The left side first feed dog slot is extending toward the second feed dog slot side in the cloth send-in side of the portal shaped needle hole, so as to be formed a wide breadth portion from side to side. A first cross-piece of the needle plate is disposed between the wide breadth portion and a needle drop portion of the portal shaped needle hole, and a second cross-piece of the needle plate is disposed between the second feed dog slot and said needle drop portion. The first cross-piece is formed wider in the cloth feed direction than the second cross-piece. A differential feed dog disposed in the cloth send-in side of the needle drop portion is composed in a shape combining each feed dog slots.

Abstract: The present invention relates to an apparatus for preventing a double chain stitching from raveling. Looper thread engaging structure engages with the looper thread consecutive to the looper from the cloth by moving when the looper is at the forward position and forms a looper thread loop consecutive from the cloth at the engaged portion by driving a sewing machine in the engaged state. A looper thread cutter cuts the looper thread loop at the engaged portion and a thread cutter cuts the loop-shaped needle thread consecutive to the needle via the looper from the cloth and the looper thread consecutive to the looper from the cloth between the cloth and the looper. Therefore, it is able to prevent a double chain stitching from raveling from the stitching end side. Further, defining structure is provided to define the moving distance of the looper thread engaging structure.

Abstract: An apparatus for detecting thread breakage in a sewing machine. The sewing machine comprises a looper reciprocating laterally across a leading end of a needle, a thread-controlling cam fixed on a rotary shaft interlocked with the reciprocal motion of the looper and varying in the extent of projection from the thread take-up stand along with rotation of the shaft, and thread guides disposed on the thread take-up stand at both sides of the thread-controlling cam. Said thread guides have thread eyelets for inserting the looper thread. Other thread guides having thread pass eyelets for inserting the looper thread are fixed and disposed on the looper thread route between the thread-controlling cam and the looper. A thread breakage-detecting member detects presence or absence of vibration of looper thread inserted in the thread pass eyelets of other thread guides between the other thread guides.

Abstract: A method and apparatus for preventing a seam from raveling in a double chain stitch sewing machine according to the present invention are applied to sewing of cloth by a double chain stitch sewing machine. Near the sewing end point for forming a double chain stitch by collaboration of a plurality of needles and a looper, the looper thread consecutive to the looper from the cloth is hooked and engaged on the hook at the left side of the needles. After driving the sewing machine for a half stitch or one stitch in this state, the looper thread hooked on the hook is cut off. Simultaneously with this cutting or before or after the cutting, the needle thread loop consecutive to the needles from the sewing end of the cloth through the looper is cut off between the looper and the cloth. Further, capturing the cut looper thread consecutive to the looper from the cloth, the end of the cut looper thread is pulled out from the final needle thread loop at the end of sewing.