Abstract: A thread cutting mechanism is mounted on a sewing machine which includes a sewing platform. The thread cutting mechanism includes a driver assembly and a thread cutting assembly. The driver assembly includes a stepping motor, a swing lever pivotally connected to the stepping motor, and a pushing rod connected to the stepping motor and swing lever and driven jointly with the swing lever by the stepping motor to perform a back-and-forth process. The thread cutting mechanism is disposed on the sewing platform, and includes a thread hooking blade connected to and driven by the swing lever to move back-and-forth along a thread hooking path and to hook back a sewing thread, and a thread cutting blade disposed on the thread hooking path and for cutting the sewing thread when the thread hooking blade hooks back the sewing 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: A method for cutting the lower and at least one upper thread for lead-in embroidering or lead-in sewing is performed with a device including thread catchers (19a-19c) connected with each other in a fixed manner and layered over top of each other, formed of sheet metal, as well as spring and thread tightening plates (31 and 41) arranged above and below the thread catchers, which move back and forth against a blade (29), and a thread wiper unit. The device is exclusively operated by a drive moving back and forth and driving the thread cutting and lead-in stitching unit (5).

Abstract: A thread cutter for a sewing machine includes a first thread seizing assembly reciprocally movable and having a distal end with a first thread seizing portion, a second thread seizing assembly seizing needle and bobbin threads both having been seized by the first assembly during a backward movement of reciprocation of the first assembly, cutting the needle and bobbin threads in cooperation with a cutting blade, and a thread cutting frame supporting the first assembly and formed with a single elongated groove supporting the first assembly so that the first assembly is movable. The elongated groove includes a linear proximal end groove, an oblique portion, and a main groove and being shaped such that the proximal end groove is translated slightly forward through the oblique portion. When moved backward in the reciprocation, the first assembly is swung so that the first thread seizing portion comes close to the second assembly.

Abstract: A thread cutter for a sewing machine includes a first thread seizing assembly reciprocally movable and having a distal end with a first thread seizing portion, a second thread seizing assembly seizing needle and bobbin threads both having been seized by the first assembly during a backward movement of reciprocation of the first assembly, cutting the needle and bobbin threads in cooperation with a cutting blade, and a thread cutting frame supporting the first assembly and formed with a single elongated groove supporting the first assembly so that the first assembly is movable. The elongated groove includes a linear proximal end groove, an oblique portion, and a main groove and being shaped such that the proximal end groove is translated slightly forward through the oblique portion. When moved backward in the reciprocation, the first assembly is swung so that the first thread seizing portion comes close to the second assembly.

Abstract: A thread cutter for a sewing machine includes a first thread seizing assembly reciprocally movable and seizing a needle thread having passed a bobbin case and a bobbin thread by a first thread seizing portion, a cutting blade located nearer to the needle hole side than a movement locus of the first assembly, and a second thread seizing assembly seizing both threads having been seized by the first assembly during backward movement of reciprocation of the first assembly, cutting both threads in cooperation with the cutting blade. When moved backward in the reciprocation, the first assembly is swung so that the first thread seizing portion comes close to the second thread seizing assembly. The second assembly has a distal end on which a second thread seizing portion is located. The second thread seizing portion is two-forked so that the cutting blade is interposed between the two-forked portions.

Abstract: A thread cutting device for a sewing machine with a hook rotatable in a vertical plane includes a drive motor, a fixed knife which has a working-side wall extending towards a thread fetching zone of the sewing machine to terminate at a first cutting edge, and a movable knife which is driven by the drive motor to angularly move between fetching and thread cutting positions in a vertical plane. The movable knife has a lateral edge surface defining a cavity in an intermediate segment thereof to engage lower and upper threads when the movable knife reaches the fetching position. The movable knife has a second cutting edge disposed to press the first cutting edge so as to complete a cutting action.

Abstract: A thread cutting device of a sewing machine is provided. The thread cutting device cuts a thread extending between a horizontal shuttle and a throat plate of the sewing machine. The thread cutting device includes a fixed blade, a first thread catcher, a second thread catcher, a driving assembly which moves the first and second thread catchers such that the first thread catcher catches the thread before the second thread catcher catches the thread and pulls the thread toward the fixed blade to cut the thread, and a guide member disposed between the first thread catcher and the driving assembly. The guide member guides the first thread catcher from an advanced position to a thread catching position to catch the thread, and further guides the first thread catcher from the thread catching position to a standby position to turn the first thread catcher toward the fixed blade.

Abstract: A thread cutting device of a sewing machine cuts a thread below a throat plate through which a needle is inserted. The thread cutting device includes a first thread catcher operable to catch the thread, a second thread catcher operable to catch the thread caught by the first thread catcher, a fixed blade operable to cut the thread caught by the second thread catcher, a driving portion which drives the first thread catcher and the second thread catcher such that the second thread catcher catches the thread caught by the first thread catcher and guides the thread toward the fixed blade, an attaching member to which the fixed blade is fixed and into which the second thread catcher is slidably inserted from above over the fixed blade, and a cover which covers the second thread catcher from above to restrict an upward movement of the second thread catcher.

Abstract: A thread cutting device for a sewing machine with a hook rotatable in a vertical plane includes a drive motor, a fixed knife which has a working-side wall extending towards a thread fetching zone of the sewing machine to terminate at a first cutting edge, and a movable knife which is driven by the drive motor to angularly move between fetching and thread cutting positions in a vertical plane. The movable knife has a lateral edge surface defining a cavity in an intermediate segment thereof to engage lower and upper threads when the movable knife reaches the fetching position. The movable knife has a second cutting edge disposed to press the first cutting edge so as to complete a cutting action.

Abstract: One embodiment of the present invention relates to a system for thread handling (e.g., separating) and/or cutting. Another embodiment of the present invention relates to a method for thread handling (e.g., separating) and/or cutting. In one example, the present invention may be used in connection with sewing machines, embroidery machines, quilting machines and the like.

Abstract: A thread cutting device of a sewing machine is provided. The thread cutting device cuts a thread extending between a horizontal shuttle and a throat plate of the sewing machine. The thread cutting device includes a fixed blade, a first thread catcher, a second thread catcher, a driving assembly which moves the first and second thread catchers such that the first thread catcher catches the thread before the second thread catcher catches the thread and pulls the thread toward the fixed blade to cut the thread, and a guide member disposed between the first thread catcher and the driving assembly. The guide member guides the first thread catcher from an advanced position to a thread catching position to catch the thread, and further guides the first thread catcher from the thread catching position to a standby position to turn the first thread catcher toward the fixed blade.

Abstract: A thread cutter for a sewing machine includes a first thread seizing assembly reciprocally movable and including two unit thread seizing members having distal ends formed with first thread seizing portions respectively, a cutting blade located nearer to the needle hole side than a movement locus of the first assembly, and a second thread seizing assembly seizing the needle and bobbin threads both seized by the first assembly during backward movement of the first assembly, cutting the threads in cooperation with the cutting blade. When the threads seized by the first assembly are further seized by the second assembly, the first assembly is moved so that the distal ends of the unit thread seizing members are spaced from each other by a predetermined distance in a direction intersecting a movement direction of the first assembly.

Abstract: A thread cutter for a sewing machine includes a first thread seizing assembly which is reciprocally movable and has a distal end formed with a first thread seizing portion, the first thread seizing assembly seizing a needle thread passing a bobbin case and a bobbin thread by the first thread seizing portion, the needle thread passing the bobbin case, a cutting blade located at a position nearer to the needle hole than a movement locus of the first thread seizing assembly, a second thread seizing assembly seizing the needle and bobbin threads both seized by the first thread seizing assembly during a backward movement of reciprocation of the first thread seizing assembly, cutting the needle and bobbin threads in cooperation with the cutting blade. When moved backward, the first thread seizing assembly is swung so that the first thread seizing portion comes close to the second thread seizing assembly.

Abstract: One embodiment of the present invention relates to a system for thread handling (e.g., separating) and/or cutting. Another embodiment of the present invention relates to a method for thread handling (e.g., separating) and/or cutting. In one example, the present invention may be used in connection with sewing machines, embroidery machines, quilting machines and the like.

Abstract: A looper is brought into an advance state at the end of sewing, and a looper thread hanging hook arranged on the right rear side of a needle drop position is forced to advance and retreat to catch a looper thread running to the rear side of the looper and hold it on the rear side of the needle drop position. After performing sewing for one stitch in this state, the thread cutting hook arranged on the right side of the needle drop position is forced to advance and retreat to catch the looper thread running to the rear side of the looper with a first hold section and catch needle threads and the looper thread held by the looper thread hanging hook with a second hook section, and then these threads are collectively cut by bringing them into slide-contact with a thread cutting knife.

Abstract: The present invention relates to a method and an apparatus for operating a thread-processing machine having a thread-cutting device. In order to provide a method and a corresponding apparatus for operating a thread-processing machine having a thread-cutting device, which achieves improved results with increased operational reliability in comparison with known apparatuses and methods, it is proposed that the processed product (3) is covered with an articulated or flexible protective element to protect the surface of the sewn product in a region around a thread (2) which is to be severed only after the thread-processing operation is ended, and the thread-cutting device (4) is moved onto a cutting point and is positioned for cutting relative to the protective element.

Abstract: A transverse longitudinal-cylinder sewing machine includes an automatic thread loosening device, a tension adjustment mechanism, an automatic thread cutting bi-directional solenoid device and a differential fabric driving teeth displacement control device. The differential fabric driving teeth displacement control device consists of a primary transmission mechanism, first and second push mechanisms, a rocking mechanism, first and second adjustment mechanisms that are co-axle, and first and second fabric driving mechanisms located inside a cylinder normal to the co-axle. The axial direction of the cylinder is directed towards the operator so that the axis of the cylinder is normal to the entire transverse work station of the sewing machine.

Abstract: An automatic thread cutting apparatus for sewing machines to cut off a thread and hold the remaining portion of bottom yarns after sewing operation is completed includes a thread cutter, a linkage mechanism and a driver. The thread cutter includes a cutting blade and an upper and a lower fixed blade. The cutting blade has a first cutting section and a second cutting section. When the driver provides power to drive the linkage mechanism, the cutting blade is swung between the upper and lower fixed blades. The thread is cut off by the first cutting section and the bottom yarns are cut off by the second cutting section and held for use in the successive sewing operation without the need of redoing yarn threading.

Abstract: A sewing machine includes a needle plate having a needle hole through which a sewing needle is allowed to pass, a thread catcher reciprocally moved forward and backward below the needle plate and being elongated in a moving direction, the thread catcher having a frontward end with respect to a direction of forward movement of the thread catcher and including first and second generally hook-shaped catching portions, and a cutting blade located between the first and second catching portions at least during backward movement of the thread catcher to cut a thread caught between the first and second catching portions. The first catching portion is located nearer to the frontward end of the thread catcher than the second catching portion with respect to the moving direction of the thread catcher during forward movement of the thread catcher.

Abstract: A device for cutting of one or more sewing threads in a sewing machine, which operates with one under thread (15) and at least one upper thread (17), including a thread fetcher (18) which is displaceable to catch and bring with at least one of the threads to a cutting position, and a knife (26), which cooperates with the thread fetcher (18) to cut the thread or the threads. The thread fetcher is movable between the cutting position and at least one thread catching position to selectively catch the upper and/or the under thread. The device cooperates with the knot forming mechanism of the sewing device, whose gripper (12) brings the upper thread (17) in catching position. The device also enables the pulling down of the free end of the upper thread under the fabric before the sewing starts.

Abstract: A thread cutting device is provided in a sewing machine that is operable to form stitches on a fabric using an upper thread and a lower thread. The thread cutting device may include a fixed knife and a movable knife cooperating with each other to cut either one or both of the upper and lower threads. The movable knife may be operable to cut the upper thread at a first timing and to cut the lower thread at a second timing that is different from the first timing.

Abstract: The fabric-side hook thread end (GN), which was previously longer than the fabric-side needle thread end (NN) by the amount corresponding to a stitch length, is to be shortened in sewing machines with a thread-cutting device. This object is accomplished by the feed device of the sewing machine, of which there is at least one, performing a partial feed step in the reverse feed direction during the performance of the thread-cutting process.

Abstract: A thread cutting device of a sewing machine comprises: a movable knife having a thread pickup portion and being movable between a standby position and a thread pickup position; a fixed knife being movable between a standby position and an operating position close to a needle locating point and cutting sewing threads in cooperation with the movable knife at the operating position; a front stopper for holding the fixed knife at the standby position, wherein the front stopper is released from the fixed knife in the course of the movable knife making a forward movement; and a rear stopper for holding the fixed knife at the operating position, wherein the rear stopper is released from the fixed knife in the course of the movable knife making a backward movement and after the sewing threads have been cut.

Abstract: A thread cutting device for a sewing machine of chain sewing includes a fixing plate, a combine plate on the fixing plate, a slide guider movably combined with the combine plate by a swing arm located between the fixing plate and the combine plate. A main knife is fixed on a front end of combine plate, and a movable knife is fixed on the slide guider to be moved moved back and forth by the slide guider so that the movable knife may hook and retract threads for the main knife to cut off when the swing arm is swung by an air pressure cylinder having its piston rod connected with an second end of the swing arm, while a first end of the swing arm is connected with the slide guider.

Abstract: A needle thread restraining device in a thread cutting sewing machine comprising a needle thread restraining device 18 which is disposed on a needle thread path between a needle take-up mechanism (5) and a needle thread supplying source (6) for setting the tension of the needle thread 4 to substantially zero when the thread cutting mechanism (9) does not operate and to a given value when the thread cutting mechanism (9) operates, and a tension nullification means 31 for setting the tension applied by a tension regulator (10) to a given value when the thread cutting mechanism (9) does not operate and for nullifying the tension applied by the tension regulator when the thread cutting mechanism operates. The amount of the needle thread to be drawn under the work can be set properly and independently, nullifying of the tension set by the tension discs when the sewing thread is cut by the thread cutting mechanism.

Abstract: An under trimming device with inclinedly movable catchers for a multi-needle sewing machine with multiple longitudinally extended loopers comprises a cutting and clamping part, a fixed cutter, a plurality of looper assemblies and a thread push plate, characterized in that: the movable catcher of the cutting and clamping part and the looper form an angle of inclination such that when performing the thread cutting, the movable catcher extends toward the looper at an angle of inclination, and extends into the needle thread loop and the looper thread loop, and when the movable catcher returns to its initial position, the looper thread and the needle thread are cut off sequentially when they pass the fixed cutter, and the free end of the looper thread after being cut is still clamped between the leaf spring and the movable catcher, and the free ends of the cut needle threads are blown sideward in the opposite direction by an air blower to facilitate a next sewing.

Abstract: A thread cutting device in a sewing machine includes a fixed knife and a movable knife cooperating with each other to cut a thread. The movable knife is movable to bring a part of the thread to extend below the fixed knife for the cutting operation. A thread protection member is operable to support the thread so as to prevent the thread from breakage prior to the cutting operation through cooperation between the fixed knife and the movable knife. The thread protection member is formed separately from the fixed knife.

Abstract: A thread cutter for a chain stitch sewing machine which performs chain stitch sewing by cooperation of a needle driven up and down and a looper arranged under a needle plate, including: a movable knife arranged so that it can advance into or retract from a gap between a top surface of the looper and an under surface of the needle plate; a knife driving mechanism for advancing and retracting the movable knife; a stationary knife arranged under the needle plate for cutting a sewing thread in cooperation with the movable knife when the movable knife is retracted; and a thread holding plate for holding a cut end of the sewing thread on the side of the looper in a predetermined position by a further retracting operation of the movable knife after the sewing thread is cut and a drive unit for a multi-sewing machine.

Abstract: A bobbin thread end holding device in a sewing machine in which an upper thread and a bobbin thread are used holds an end portion of the bobbin thread after cut. The bobbin thread end holding device has a cutter for cutting the upper thread and the bobbin thread, and a bobbin thread control member. The bobbin thread control member includes: a thread control hole into which the upper thread and the bobbin thread are led; and a prolongation extending from the control hole, for outwardly introducing the end portion of the bobbin thread cut by the cutter from the control hole.

Abstract: A thread-cutting mechanism for a sewing machine (2), especially an eyelet-buttonhole sewing machine with a moving blade (12 or 12") and a stationary blade (16). The moving blade travels back and forth in a groove (19) in a plate (1) with an aperture for the needle to pass through while it is producing a stitch. The needle-aperture plate comprises at least a top (11 or 11") and a bottom (10 or 10"). The moving blade is entirely accommodated between the top and the bottom of the plate. The stationary blade is part of the top.

Abstract: An under trimming device for a multi-needle sewing machine with multiple longitudinally extended loopers mainly including a cutting part and a clamping part. Both the cutting and the clamping parts are longitudinally and reciprocatingly movable, so that multiple looper threads may be pulled by multiple movable catchers of the cutting part into the clamping part before they and corresponding needle threads are simultaneously cut by a fixed cutter of the cutting part, permitting free ends of the cut threads to have uniform length and being held at the same position.

Abstract: In a process and a device for shortening the needle thread end at the beginning of sewing and at the end of sewing in two-thread lockstitch sewing machines, the catch thread device (23) of an already existing thread-cutting device (22; 60; 90) is moved into its thread-catching position during the first stitch formation cycle, and it is ensured, either by the selection of a suitable point in time for moving the catch thread device (23) or by a compressed air flow discharged from a compressed air line (81), that at least the reserve-side leg of the needle thread loop will be caught by the catch thread device (23). Part of the needle thread end is cut off during the return movement of the catch thread device (23) into its starting position. Furthermore, the needle thread is clamped either under a leaf spring (44), or is pushed by a sufficiently large feed step under the pressure foot, and is thus held in a frictionally engaged manner.

Abstract: A thread cutting device for a sewing machine includes a stationary blade which is disposed downwardly of a needle plate and a movable blade. The stationary blade is provided at its one end with a cutting edge. The movable blade which is formed with a cutout in the surface opposite to the stationary blade, is adapted to rotate about a shaft and pass over the needle plate and the stationary blade. The cutout is adapted to catch and guide a thread along a path for the thread and provided with a cutting edge to cooperate with the cutting edge of the stationary blade to cut the thread. A through hole is formed between the cutout and the cutting edge of the movable blade to meander the thread through the hole.

Abstract: A looper is rotated under a throat plate, a stitching needle moves up and down through a needle hole formed in the throat plate and thus a cloth on the throat plate is stitched. After the cloth has been stitched, the thread between the needle hole and the looper is brought to a thread holding means disposed aside by thread drawing pieces and is maintained at its position by the thread holding means. Accordingly, even when the thread at this position is cut over the thread holding means, the thread can remain extending from the looper.

Abstract: The bobbin case which is received by the looper has an upstanding generally cylindrical wall which surrounds the looper-thread bobbin. Forming part of the wall is a free-standing finger against which an end of a leaf spring rests. The looper thread, which has been withdrawn from the looper-thread bobbin and wrapped around the finger, is pulled through the constricted place between the leaf spring and the finger and then conducted through a threading slot provided by a radially-extending cam on the outer surface of the wall. The looper thread then comes against an inclined, downward-facing shoulder provided on the outside of the wall, slides down the shoulder, and passes finally into a long horizontal slot in the wall. The looper thread exits the bobbin case at an end point of the horizontal slot for being dependably caught by a thread catcher of a thread-cutting device.

Abstract: An automatic thread trimming method and apparatus are provided for tack and jump sewing of fabrics. In a preferred embodiment, a quilting apparatus having a plurality of sets of, preferably, double lock chain stitch forming elements, is disposed on a mechanically linked mechanism in a reconfigurable array corresponding to an array of discrete patterns to be sewn. Each set of the array is equipped with a thread trimming element. In a preferred embodiment, a thread trimming cutting edge is formed on one surface of a thread stitch forming element, preferably on a revolving retainer element that is mechanically linked to the mechanism. When operated in a forward direction, a chain stitched pattern is sewn with the stitches formed in cooperation with the retainer revolving in a forward direction.

Abstract: A thread trimmer for a pattern sewing machine is disclosed. When the pattern sewing machine forms patterns, a pattern is connected to a next pattern by a crossover thread. The thread trimmer automatically cuts a specified portion of the crossover thread. Therefore, the operator can avoid the troublesome and time-consuming cutting of the crossover thread manually with scissors. Furthermore, the sewing efficiency of the pattern sewing machine is enhanced.

Abstract: A thread cutting device includes a movable knife positioned below a throat plate and movable from a first position to a thread cutting position via a second position for separating the upper fabric thread and the upper needle thread from each other within the range where the movable knife may engage the upper fabric thread and the upper needle thread but may not engage or cut the lower thread. The movable knife includes an engaging portion for engagement with the upper needle thread on the side toward the second position and a cutting edge on the opposite side. The movable knife also includes a thread separating portion for separation of the upper fabric thread and the upper needle thread between the needle hole and the bobbin holder from each other toward the cutting edge and the engaging portion, respectively, when the movable knife moves from the first position to the second position.

Abstract: Apparatus and method for severing the needle and looper threads of a chain stitch formed by a cylinder bed sewing machine having an in-line looper system is disclosed. The cylinder bed sewing machine has a needle plate and a needle carrying the needle thread through the material and the needle plate to form a needle loop of needle thread therebelow that has a needle side running to the needle. The apparatus comprises a device operating as a dual needle plate holder and knife slide base, a stationary knife positioned below the needle plate, a spring positioned below said stationary knife, a movable knife positioned on the knife slide base and slidably mounted between the stationary knife and the spring for yieldingly urging the movable knife thereagainst. The movable knife has one penetrating end with a pair of axially offset barbs, a lagging barb and a leading barb closer to the penetrating end of the movable knife than the lagging barb.

Abstract: A thread cutting arrangement for sewing machines including an arrangement in which the tension of the thread is released in both directions of movement of an axially moveable drive mechanism such that the thread tensioning mechanism is opened when the needle thread is caught. The movement of the drive mechanism is transmitted via a one-way coupling so that the opening of the thread tensioning mechanism is limited to the duration of the after pawal of the needle thread.

Abstract: In a thread trimmer mechanism on a sewing machine, a movable knife for catching and cutting thread and a bobbin pressing member for pressing and applying frictional resistance to a bobbin are operated synchronously with a rotary hook assembly. After needle thread caught by a hook of the rotary hook assembly has passed the end surface of the bobbin, the bobbin pressing member presses the end surface of the bobbin. Therefore, the needle thread is prevented from being caught in the bobbin pressing member and from being excessively supplied. Almost at the same time as the bobbin pressing member presses the end surface of the bobbin, the movable knife catches and cuts the thread. Consequently, even when the movable knife pulls bobbin thread from the bobbin, the bobbin is prevented from spinning freely. As a result, only a short thread extends from the last stitch on cloth, thus enhancing the appearance of the cloth and possibly eliminating a separate trimming operation.

Abstract: A sewing machine provided with a thread cutting mechanism and a needle thread tension release mechanism. Normally, the needle thread is subjected to a proper tension by a thread tension regulating mechanism. However, at an initial start-up period of the sewing operation, the needle thread tension is released by the tension release mechanism for a first predetermined period during which a needle thread loop is trapped by a loop taker. Further, the sewing machine is provided with a thread holding member for holding a leading end portion of the needle thread. The holding member is movable to its thread release position after elapse of a second predetermined period at the initial start-up period of the sewing operation. The first predetermined period is within the second predetermined period.

Abstract: A thread cutting knife device in a sewing machine having a bed has a lower shaft rotatably supported at the bed and a throat plate mounted thereon. A hook is attached to the lower shaft and extends beyond a throat plate. A thread cutting knife and a loop spreading plate are adapted to cross between the hook and the throat plate to cut a needle thread looping portion at a cloth side and a bobbin thread. The knife and the plate are respectively rotatably supported by the lower shaft. The knife has a blade at an upper edge of the tip end thereof. The loop spreading plate has a thread dividing portion extending into the needle thread looping portion at the cloth side and a thread looping portion at the side of the needle. A thread drawing portion is formed at one edge of a base of the dividing portion for holding the needle thread looping portion at the cloth side and the bobbin thread. A blade positioned at the side of the throat plate and is opposed to and crosses the blade of the thread cutting knife.

Abstract: A slackened needle thread assuring unit includes a thread tension member mounted on a side wall of a frame secured to the bed of a sewing machine. A thread takeup is positioned above the thread tension member. A needle/bobbin thread cutter is positioned apart from and under the frame for cutting a needle thread. A thread end holder holds an end of the thread to be cut by the needle/bobbin thread cutter. A thread guide extending across the front portion of the frame has one end supported by a support plate and the other free end defining a hook. A drive mechanism supported by the support plate reciprocally moves the hook in the direction substantially perpendicular to the threading direction of the needle thread.

Abstract: A thread cutting unit cooperating with the bed of a sewing machine includes a lower shaft, a cutting knife and a loop spreading plate respectively fixed to the lower shaft and positioned adjacent to the hook. The thread cutting knife and the loop spreading plate cross each other in a space between the hook and the throat plate. The thread cutting unit is provided with a thread cutting driving unit which comprises a thread cutting knife driving shaft, a loop spreading plate driving shaft, a rotational motion transmission device, a thread cutting supporting member carrying thread cutting knife, a first turnable interlocking mechanism and a second turnable interlocking mechanism. The thread cutting supporting member is rotatably supported on the bed.

Abstract: A thread-cutting device for zigzag sewing machines for forming uniformly short thread ends regardless of the top stitch position of the last stitch. The thread cutter 28 is movable in a plane that is parallel to the thread catcher 33 and is connected by a drive unit 45 through 58 having stop sections 54, 55 to the drive of the thread catcher 33 such that the thread catcher can be moved, together with the cutter, into the cutting position located below the center of the stitch hole. While the thread cutter 28 stops in the cutting position, the thread catcher completes the thread separation process. The thread cutter 28 is moved back during the return movement of the thread catcher 33 only after the threads have been cut. The drive unit 45 through 58 for the thread cutter 28 is of positive-locking design, as a result of which even thick threads are cut reliably. The thread cutting device is particularly suitabloe for installation (even subsequent installation) in stitch group zigzag sewing machines.

Abstract: A bobbin thread holding device for a lockstitch sewing machine adapted to temporarily form an entrapping hole under a throat plate wherein a bobbin thread is captured. A recess provided at the sidewall of the throat plate and a hook with a crooked portion at one end form the entrapping hole. A movable blade, provided underneath the throat plate, moves to cut the bobbin thread. In cooperation with the motion of the movable blade, the hook picks up the bobbin thread and, as the bobbin thread is held in the entrapping hole, the bobbin thread is crossed with a needle thread loop.

Abstract: A thread undercut attachment for use on multi-needle sewing machines uses a single piston actuated cutting blade which passes through the sewing area beneath the workpiece and above the loopers. To prevent the needles and loopers from becoming unthreaded or to prevent undue lengths of thread after cutting, apparatus is provided for creating a measured amount of slack in the threads leading to the needles and loopers, and then holding the threads firmly to prevent further payout of thread when the workpiece is pulled toward the operator.

Abstract: A thread cutter for an interlock sewing machine wherein the sewing machine has a small diameter cylindrical arm and the cloth being sewn is fed along the axis of the arm. A plurality of needles are disposed along a line orthogonal to the axis of the arm and an arcuated, movable member having a hook at its tip is pivotably supported ahead of feed dogs on the sewing machine relative to the line of feed. The arcuated, movable member is turned by means of an operative plate disposed along the axis of the arm and, in cooperation with a fixed blade, cuts threads after the cloth has been sewn.