Abstract: A system and methods for stitching are disclosed. The system includes a first thread feeding mechanism configured to feed a continuous supply of a first thread, a second thread feeding mechanism configured to feed a continuous supply of a second thread, a plate separating the first thread feeding mechanism and the second thread feeding mechanism, and a knot tying mechanism configured to pass a bight of the first thread for at least one turn around a portion of the second thread and securing the bight around the second thread.

Abstract: Improved needle bar driving system for sewing machines, that comprises an armshaft rotating with a predetermined speed; a needle bar driving assembly driven by the armshaft and has a needle bar that performs a reciprocating guided linear movement along a substantially vertical axis; a counterweight driving assembly is driven by the armshaft; and a counterweight piston driven by the counterweight driving assembly, and the counterweight piston also performs a reciprocating linear guided movement along an axis parallel to the axis, wherein the movements of the counterweight driving assembly and of the counterweight piston are always opposite to the movement of the needle bar driving assembly and of the needle bar, wherein the combined torque of the counterweight piston and the counterweight driving assembly acting on the armshaft is substantially equal to the combined torque of the needle bar and needle bar driving assembly acting also on the armshaft, but the two torques have opposite direction, whereby the arm

Abstract: A method for preventing seam ravel of multi-thread chain stitches is provided. After normal sewing is terminated with a looper set in a forward movement state, a state in which a needle thread loop caught by the looper is subjected to position-holding at a position closer to a forward movement end of the looper than a descent position of a needle is maintained until the needle descends through the needle thread loop caught by the looper. Thereafter, the position-holding of the needle thread loop is released to permit a sewing action for at least one stitch, thereby allowing the needle thread loop to be self-looped with a needle thread held by the needle. This surely strongly prevents the seam ravel of multi-thread chain stitches formed by the single needle, irrespective of the dimension of tension applied to the needle thread and the looper thread.

Abstract: A thread hook and a looper thread holder are arranged on a rear side of a needle drop position of a sewing machine. When usual sewing is completed, the thread hook and the looper thread holder swing and move close to a looper. A hook part provided at a tip end of the thread hook holds a needle thread loop caught by the looper and positions it on an advance end side of the looper away from the needle drop position, and a thread receiving part provided at a tip end of the looper thread holder holds a looper thread extending from the looper to cloths and positions it on the front side away from the needle drop position. The sewing machine performs sewing for at least one stitch while maintaining positions of the needle thread loop and the looper thread.

Abstract: To provide a seam of attractive appearance in which tightening force is increased and raveling are prevented drastically. A seam (1) is formed by two needles (11, 12) juxtaposed in the direction at substantially right angles to the sewing direction (T), and consists of a chain seam (10) formed by a needle thread (12) passed through one needle (11), and a lock seam (20) formed by a needle thread (22) passed through the other needle (21). The loop (13) of a needle thread forming the chain seam (10) is passed through the loop (23) of a needle thread forming the lock seam (20) before tightening of stitch is performed, and a loop of the needle thread forming the chain seam located on a downstream side in the sewing direction is passed through the loop of the needle thread forming the upstream chain seam.

Abstract: A method for operating a chain stitch sewing machine and a chain stitch sewing machine, the chain stitch sewing machine having a pair of sewing members comprising a needle which pierces a sewing material and a gripper disposed below a sewing material rest, which can be moved along a movement path, where an upper thread is guided with the needle through the sewing material resting on the sewing material rest, which is linked to a lower thread. The lower thread is fed to a retaining element and is held in said element that is moved with regard to its direction of movement and/or speed of movement to the sewing material rest according to a movement path of a pivoting movement of the gripper in particular along a circular-arc-segment-shaped movement path.

Abstract: A flat seam construction made up of a number of sequentially formed stitches and formed on a portion of one or more stitchable materials is disclosed. Each stitch has two outer threads, formed into first and second outer thread loops, and at least one inner thread, formed into at least one inner thread loop. Each of the inner and outer thread loops transversely penetrate the one or more stitchable materials. Each of the inner and outer thread loops have a bight portion engaging a bottom surface of the one or more stitchable materials. At least one looper thread is formed on the bottom surface, and arranged such that, the at least one looper thread passes between the bottom surface and at least one of the bight portions. At least one decorative thread is visible on a top surface of the seam construction.

Abstract: A multiple needle sewing machine. The sewing machine includes a needle head, a first needle and a second needle both coupled to the head, a drive mechanism, a gripper shaft, and a first gripper hook and a second gripper hook both coupled to the gripper shaft. The drive mechanism is configured to translate the first needle together with the second needle, and to individually translate only one of the first needle or the second needle.

Abstract: In a sewing machine for covering chain stitch according to the present invention, a thread push member is mounted on a top cover shaft which drives a cover thread looper, and the thread push member is arranged on the cover thread guide. When swinging backward in association with a movement of the cover thread looper, the thread push member pushes the top cover thread passing through a guide hole of the cover thread guide, forcibly moves the top cover thread and keeps the top cover thread near a back end of the guide hole. The top cover thread is arranged at a predetermined position on a surface of a cloth without being affected by a force from the needle thread, and a covering chain stitch can stably be formed with the excellent appearance.

Abstract: A multi-needle chain-stitch quilting machine and method of operation thereof are provided that imparts relative motion between the needles and the material that is controlled so as to pull needle thread tails from the needle side of the quilted material. The feature of controlling thread tails may be optional to provide selection of either a high speed mode of operation without thread tail control or a quality mode of operation with reduction or removal of needle thread tails from the face of the quilted material. Thread trimmers may be included at each needle location on the looper side of the material to cut both needle and looper threads.

Abstract: A threading device of a sewing machine is provided. The threading device includes a threading hook which moves forward to enter an eye of a needle to catch a needle thread, and moves rearward with the needle thread being caught to insert the needle thread through the eye, a threading shaft which holds the threading hook, an operating member which is operated to move the threading shaft, a threading operation mechanism which transmits the movement of the threading shaft to the threading hook to move the threading hook back and forth, and a restricting device which makes the threading operation mechanism inoperable when the spreader mechanism is attached to the sewing machine main body, and makes the threading operation mechanism operable when the spreader mechanism is detached from the sewing machine main body.

Abstract: A sewing thread (20) can be captured certainly with a thread capturing open eye (13a) of an open eye needle (13) and the stitches are formed in the inner space of a sewing machine bed (3). A handstitch and a locked stitch are formed, respectively, on the front surface and the back surface of a fabric workpiece (21) as a skip stitch set through cooperation of the open eye needle (13), a shuttle hook (200) and a thread draw out actuator (401). A feed dog (601) feeds the fabric workpiece by a stitch length (P1) for handstitch during a first stroke of the open eye needle (13), and feeds the fabric workpiece by an inter-stitch pitch (P2) between the handstitches during a second stroke of the open eye needle (13).

Abstract: A chain stitch or a double chain stitch sewing machine or sewing element of a sewing machine comprising three elements: a needle; a looper; and a spreader improved in such a way that a collision of any two of the elements during the sewing operations will not cause serious damage to the sewing machine and stop periods as a consequence thereof. It is provided that the sewing elements are formed such that at least one sewing element, in particular the spreader, will dodge or break at the predetermined breaking point due to its design and/or material properties.

Abstract: In a sewing machine for covering chain stitch according to the present invention, a thread push member is mounted on a top cover shaft which drives a cover thread looper, and the thread push member is arranged on the cover thread guide. When swinging backward in association with a movement of the cover thread looper, the thread push member pushes the top cover thread passing through a guide hole of the cover thread guide, forcibly moves the top cover thread and keeps the top cover thread near a back end of the guide hole. The top cover thread is arranged at a predetermined position on a surface of a cloth without being affected by a force from the needle thread, and a covering chain stitch can stably be formed with the excellent appearance.

Abstract: Looper section provided under a needle plate includes: a plurality of loopers arranged in an array along a curved movement path; and a movement mechanism for moving the plurality of loopers along the curved movement path to selectively position one of the plurality of loopers in a predetermined needle drop position. Chain-stitch sewing is performed by cooperation between the one looper selectively positioned in the needle drop position and a hooked needle. The looper section projects at its one end portion including the predetermined needle drop position, and a cylindrical sewing workpiece can be taken to and from the needle drop position via the one projecting end portion. The curved movement path is, for example, a U-shaped path.

Abstract: A lower end of a thread guide lever, which is rockably attached to a lower looper and supports a thread pipe, and an air ejecting unit, which faces a thread inserting hole of the thread pipe and ejects air toward the thread inserting hole, are coupled via a coupling member so that they are interlocked with each other. The coupling member is moved such that a discharging port of an air nozzle is positioned at an ejecting position close to the thread inserting hole when a thread discharging hole is positioned at a threading position which is coincident with a thread hole of a lower looper, and such that the air nozzle is moved to a standby position when the thread discharging hole is moved to a retreating position.

Abstract: A stitch structure capable of effectively preventing the occurrence of raveling peculiar to double chain stitches irrespective of sewing conditions is provided by the stitch structure of double chain stitches including a plural number of needle threads forming rows of thread loops at the rear face of a cloth and one looper thread entwined with the rows of thread loops at the rear face of the cloth; wherein the looper thread is cut at one side of the positions at which it is entwined in the mode of interlacing with the preceding loops preceding to the final loops at the respective sewing termination ends of the respective rows of thread loops.

Abstract: The invention relates to a double chain stitch sewing machine comprising an upper machine section (10) and a lower machine section (12), which sections together define a sewing product plane (14) and can be displaced in a synchronous manner parallel to said plane. According to the invention, the upper machine section (10) comprises a needle rod (18), which can be displaced perpendicularly to the sewing product plane (14) by means of a drive (28) and which holds a needle (20), and the lower machine section (12) comprises a hook (40), which cooperates with the needle (20) to form the stitch and which can be displaced back and forth on a plane that runs parallel to the displacement direction of the needle rod (18). At least one needle stabilizer (42, 44) is located in the lower machine section (12).

Abstract: In a chain stitch sewing mechanism with a sewing head movable parallel to the sewn material plane, including a needle rod with a needle drive for reciprocating a thread carrying needle, a catcher drive for reciprocating a needle shaped thread catcher with an open catching hook. The needle and thread catcher have movement paths forming a sharp angle with one another whose apex lies beneath the sewn material plane and the needle and catcher being so controlled such that a loop formed by the withdrawal of the needle is caught by the thread catcher and pulled through the material. A thread puller on a movable thread arm is moved towards the thread catcher and cooperates with the thread catcher for deflecting the loop hanging off the thread catcher at an angle to the movement path of the thread catcher toward the side opposite to that of the hook opening.

Abstract: A chain stitch sewing machine comprises a needle for penetrating through a cloth on a throat plate to be vertically moved interlockingly with a main spindle of the sewing machine, thereby holding a needle thread, a cloth presser mounted on the throat plate and serving to press the cloth, a looper having a looper thread for reciprocating in such a direction as to cross a cloth feeding direction below the throat plate interlockingly with the main spindle of the sewing machine, a main feed dog for feeding a loop formed by the needle thread and the looper thread in cooperation of the needle and the looper rearward in the cloth feeding direction, and a loop engagement member for protruding from an upper surface of the throat plate and engaging the loop with the cloth presser when the main feed dog is descending from the upper surface of the throat plate.

Abstract: Disclosed is a chainstitch sewing machine having a plurality of needles having needle threads which are moved up and down through needle holes of a throat plate, a looper having a looper thread, which is reciprocatively moved in a direction orthogonal to a cloth feeding direction under the throat plate, guide holes provided in the throat plate for guiding loops formed by the needle threads and a looper thread by the cooperation of the needles and the looper, to a rear part in a cloth feeding direction, and a main feed dog, disposed at a part closer to a rear than the guide hole, for feeding the loops in the cloth feeding direction.

Abstract: The over lock sewing machine for forming seams of an over-edge chain stitch and a double-thread chain stitch on a work cloth is provided with a needle bar holding a plurality of needles for forming a seam by a vertical reciprocating movement a plurality of loopers and a needle bar transmitting mechanism moving the needle bar in approximately orthogonal direction relative to a cloth feeding direction of the work cloth and the vertical reciprocating direction of the needle bar. Accordingly, the over lock sewing machine can make various decorative stitches with an over-edge chain stitch function and a zigzag stitch function. Moreover, the over lock sewing machine is capable with operation at a low cost.

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.

Abstract: A needle plate of a cover stitch sewing machine, adapted to introduce double chain stitch chain-off's, which are formed below a needle plate by the intertwining of threads on three needles and a thread on a looper in accordance with actions of the needles and looper occurring when fabrics to be sewn are not fed, onto the portion of an upper surface of the needle plate which is behind needle points, and feed out the chain-off's continuously with the chain-off's held between rear feed dogs on the rear side of the needle points and a chain-off thread gripper, is provided with a thread positioning spreader formed of retainers 10A, 10B having inclined portions indexed to the needle points and provided between recesses of the needle plate so that the chain-off stitches can be sewn continuously in a stable condition by a simple structure.

Abstract: An auxiliary device (6) for sewing up the starting end of a thread chain (F) in a chain stitch sewing machine (1) having a platform (2), a needle plate (3) and an edge cutter (4) comprises a suction and separating device (5) disposed subsequent to the needle plate (3) in sewing direction (N) for taking in and cutting off the thread chain (F) upon sewing a workpiece, a returning device for turning round the remaining end piece of the thread chain against the sewing direction (N), and a clamping and deflecting device disposed before the needle plate (3) in sewing direction for retaining the end piece of the thread chain turned round, and for laterally deflecting the same into the cutting area of the edge cutter (4).

Abstract: A method is disclosed where a knot is formed in chain-stitching, and a first loop formed by a stitch to an article to be sewn, two stitches ahead of a final stitch, is drawn through a second loop which is formed by a stitch one stitch ahead of the final stitch, whereby a knot where the first loop is fastened by the second loop is formed, such that a third loop is inserted through the second loop and is then cut.

Abstract: A knot is formed in chain-stitching, and a first loop, formed by a stitch to an article to be sewn two stitches ahead of a final stitch, is drawn through a second loop which is formed by a stitch one stitch ahead of the final stitch, whereby a knot is formed where the first loop is fastened by the second loop, such that a third loop is inserted through the second loop and is then cut.

Abstract: A thread chain back-tacker for an overlock sewing machine eliminates defective back-tacking. The back-tacker includes a thread chain cutter, an adjuster for adjusting the length of free thread chain after the end of back-tacking, a presser foot, an air nozzle, a thread drawing nozzle, a thread clamp cylinder, a nozzle swing cylinder, a nozzle pulling cylinder, a cylinder retainer coupling the nozzle swing cylinder and nozzle pulling cylinder together, a position adjuster bolt provided on the cylinder retainer for adjusting a stop position of the thread drawing nozzle, a speed setting/releasing unit, a venturi unit, an air breaking valve, and a solenoid for on-off operating the air breaking valve. The presser foot includes a presser body, a presser foot chain shield secured to the rear end of the presser body, and a presser foot stitch tongue secured to a central portion of the presser body.

Abstract: Upper and lower loopers 2 and 3 are annular loopers. A pump 4 for supplying pressurized air is connected to thread introduction portions 7, which are connected to thread inlets of the loopers through annular conduits 5 and 6 and conduits 5' and 6'. The conduits 5' and 6' are slidable relatively to the conduits 5 and 6, and are connected to thread inlets of the loopers in the threading operation. In this state, the pressurized air is supplied from the pump 4 to the thread introduction portion 7, whereby the thread is transferred by the flow of the air and is fed to an outlet of the annular looper. A connecting portion moving plate 10 for connecting the conduits 5' and 6' is positioned in a disengaged position during the operation of the sewing machine by a stopper 18 and is positioned in an engaged position during a threading operation.

Abstract: An apparatus and method for maintaining the continuity of a free thread chain between successively sewn fabric parts by tensioning the free thread chain with a puller roller activated by drive means responsive to the sensing of the edges of the fabric parts.

Abstract: Apparatus and method for detecting skipped stitches for chainstitch sewing machines having a looper assembly using a needle thread movement sensor and/or a looper thread movement sensor in combination with a shaft rotation sensor. Needle thread movement is correlated with needle shaft rotation per stitch cycle to detect instances when there is no needle thread movement during a stitch cycle. Similarly, looper thread movement may be correlated with needle shaft rotation per stitch cycle to detect instances when there is no looper thread movement during a stitch cycle. The invention includes methods for detecting needle loop and triangle skips by detecting instances of substantially no needle thread or looper thread movement during certain respective portions of the stitch cycle.

Abstract: A length of a flexible material such as a monofilament nylon is folded back on itself to form a loop and an elongated guide portion. The ends and portions of the flexible material adjacent the ends are fastened together. The trailing end portion of the loop is crimped so that when the loop is flattened, it folds at the crimp. A sewing thread that has been introduced into the loop is retained as it is drawn through the narrow passages of a serger sewing machine.

Abstract: An automatic sewing machine for sewing chain stitch seams is suitable both for forward sewing and for reverse sewing. For forming chaining loops, a chaining tongue is to be disposed in the region of the needle. During forward sewing, the chaining tongue disposed on the needle plate is directed in the feeding direction. This chaining tongue (32) for forward sewing, just as a chaining tongue (34) for reverse sewing, is formed on a disk-shaped tongue carrier (30) which is embedded in the needle plate (22). The disk-shaped tongue carrier (30) is brought, via an adjusting mechanism (40 to 57), into one of two defined operational positions corresponding to forward sewing and reverse sewing, respectively. A sewing material feeder is formed as a gripper-type feeder having upper a lower gripping structures (60, 62). The lower gripping structure (60) is guided in a guide way (36) of the needle plate across the tongue carrier (30).

Abstract: A device for forming a thread chain on a multiple-needle chainstitch sewing machine having at least two sewing needles, a looper, a needle plate having at least two needle hole slots and a stitch formation tongue disposed between the needle hole slots, and a feed device comprising a feed dog and a presser foot, and a sewing thread brake device disposed beneath the stitch formation tongue beyond the sewing needles in the direction of sewing. The device brakes the sewing threads, and deflects them in such a way that a thread chain is formed.

Abstract: A method and apparatus for detecting an improper stitch for a Class 400 chainstitch sewing machine. A monitor assembly determines the consumption per stitch of the looper thread during the formation of the chainstitches. A processor identifies times when the monitored consumption is indicative of looper thread consumption per stitch below a predetermined threshold value. Since the consumption per stitch for looper thread is nominally a predetermined multiple of the stitch length, those identified times correspond to times when improper stitches have occurred.

Abstract: In a needle plate used in a sewing machine for forming double chain stitches, a recess is formed at a looper heel side of a needle hole behind a needle drop point. During the sewing of a fabric, the loop of the looper thread expands by tensioning of the needle thread and settles within the recess, so that balloon stitches are formed on the under side of the fabric.

Abstract: A method and an apparatus for changing the sewing direction of a multiple needle flat sewing machine for sewing elbow pads of sports wear, jumpers, etc. and patchworks of various shapes. Needles are stopped at the needle upper dead center position; a throat plate is moved in a direction contrary to the sewing direction; a needle thread or looper thread caught on tongues of the throat plate is released from the tongues; and the sewing direction can be changed at any desired angle in relation to the sewing direction at the start, such as a right angle, an acute angle or an obtuse angle. The present invention also makes it possible to carry out fancy stitching with thick thread by a multiple needle flat sewing machine.

Abstract: A walking needle chain stitch sewing machine having multi sewing heads laterally spaced apart from one-another, that includes upper primary drive shaft and secondary lower first and second drive shafts and mechanisms thereof for driving first and second needle-drive mechanisms, and that further includes other secondary lower third and fourth drive shafts and mechanisms thereof for driving first and second feed-dogs and mechanisms thereof, with the first and second drive shafts being connected to the primary drive shaft by respectively spaced-apart drive-belts each mounted between driving and driven gears, and with the third and fourth drive shafts likewise being connected to the primary drive shaft by respectively spaced-apart other drive-belts each mounted between other driving and driven gears.

Abstract: A device for a two-needle overedge sewing machines for sewing in a thread chain. The device has a pair of needles, and a pair of slots in a needle plate for the needles. The device further has a pair of stitch formation tongues, and a directing mechanism in order to guide the thread chain into a needle hole slot between one of the stitch formation tongues.

Abstract: The surgical suturing machine comprises a housing (10) on whose head piece (14) a needle holder (16) holding a needle (30), a thread catcher (18), a rotatable cylindrical body (20), a fixed foot with a plate (70) and a stretcher (22) are releasably mounted. The projecting tissue edges to be sutured together are clamped between plates (70) and cylindrical body (20). When the surgical suturing machine advances, the shaped circumferential surface (78) of cylindrical body (20) rolls along the outside of one edge of the tissue. The circumferential surface (78) of the rotating cylindrical body "grips" the outer surface of one tissue edge and guides the two tissue edges into a clamping zone which is located in the vicinity of the shortest distance between plate (70) and circumference (78) of the cylindrical body (20). The projecting tissue edges are pierced by needle (30) in the clamping zone and sutured together with the aid of thread catcher (18) and needle (30 ).

Abstract: A reciprocally driven needle guide movable in timed relation with sewing machine needles above the work support of a sewing machine along a substantially horizontal path. The needle guide is provided with an extended guiding surface which is positioned adjacent the vertical path of the sewing machine needles to steady the needles while they are above the work supporting surface of the machine.

Abstract: A thread chain sewing method and device for use in a two-needle overlock sewing machine. An inner chaining-off finger is held in an advanced position during sewing directly on fabric material. The inner finger is also advanced during the period at which thread chains are formed right after the sewing process passes the trailing edge of fabric material. The inner chaining-off finger is retracted from its advanced position alongside an outer chaining-off finger, in a direction opposite to a fabric material feeding direction, during other periods. The thread chains formed are wrapped only around the outer chaining-off finger before the leading edge of fabric but bridge over the inner and outer chaining-off fingers right after the trailing edge. The needle threads are automatically tightly tensioned during the sewing of fabric, the tension of the needle threads being automatically changed over to slightly tensioned for production of extensible thread chains.

Abstract: A chainstitch thread guide is formed with a thread guiding trough which extends into a channel on one side of a partitioning wall in a sewing machine to receive needle thread extending upwardly from a tensioning device to a take-up lever and further receives such needle thread extending downwardly from the take-up lever on the way to a sewing needle.

Abstract: Apparatus for making a seam from two threads, each thread being formed into bridging loops and prone loops, each prone loop of one thread embracing a doubled portion between two bridging loops of the other thread, such doubled portions forming the prone loops. The apparatus has opposed sewing-machine-type needles which move together and apart, crossing a reference plane between the needles in a pattern whereby a loop between the eye of one needle and the previously made seam, is penetrated when the first needle starts to retreat from its furthermost excursion past the reference plane, by the other needle during its approach to the reference plane. The needles of a pair are slightly staggered laterally so that they pass one another, preferably with light contact, during loop penetration.The example relates to a seam which is made upon a base fabric and in which the bridging loops of both threads are held slack to form pile loops by means of loopers.

Abstract: A multi-needle chain-stitch quilting machine and method of operation thereof are provided that imparts relative motion between the needles and the material that is controlled so as to pull needle thread tails from the needle side of the quilted material. The feature of controlling thread tails may be optional to provide selection of either a high speed mode of operation without thread tail control or a quality mode of operation with reduction or removal of needle thread tails from the face of the quilted material. Thread trimmers may be included at each needle location on the looper side of the material to cut both needle and looper threads.