Abstract: A sewing machine includes a cutting mechanism, a picker, and a drive portion. The cutting mechanism, which cuts an upper thread and a lower thread, is provided close to a shuttle that supplies the lower thread. The picker is provided such that it is able to move between an operating position and a non-operating position. The operating position is a position of the picker where the picker is proximate to the shuttle. The non-operating position is a position of the picker farther away from the shuttle than the operating position. The picker holds the upper thread in the operating position. The drive portion is provided as a common drive source for a cutting operation by the cutting mechanism and for movement of the picker.

Abstract: A cutting device for a sewing machine includes an upper-blade positioning device and a lower-blade positioning device. The upper-blade positioning device includes an upper blade upper blade fixed at a head portion of the upper-blade holder, and a spring and a restricting member sleeved on a body portion of the upper-blade holder. A restricting pin is engaged between an upper-blade drive member and the restricting member. A guide member includes a guide hole for insertion of a rod portion of the upper-blade drive member and is fixed to the base. The upper-blade drive member is inserted through a guide member of the base and moved by a connecting rod. The lower-blade positioning device includes a lower-blade holder, an adjustment member. A lower-blade shaft has one end fixed to the base and another end extended out of the base, rotating the adjustment member can adjust the position of the lower-blade holder.

Abstract: A thread cutting device is adapted to be mounted under a bed of a sewing machine, and includes a mount having a marginal region which confronts a thread fetching zone, and a guide slot which is elongated parallel to a stroke path, a fixed knife disposed on the marginal region and having a blade aligned with the stroke path, a movable knife having a shank body which extends along the stroke path to terminate at actuated and hook ends, a drive unit disposed under the mount and having a rotatable output shaft to deliver a rotational force, and a rotation/translation conversion mechanism disposed to convert the rotational force into a translational force that is transmitted through the guide slot to actuate a translation of the actuated end of the shank body to thereby move the shank body between fetching and thread cutting positions.

Abstract: A thread cutting device is adapted to be mounted under a bed of a sewing machine, and includes a mount having a marginal region which confronts a thread fetching zone, and a guide slot which is elongated parallel to a stroke path, a fixed knife disposed on the marginal region and having a blade aligned with the stroke path, a movable knife having a shank body which extends along the stroke path to terminate at actuated and hook ends, a drive unit disposed under the mount and having a rotatable output shaft to deliver a rotational force, and a rotation/translation conversion mechanism disposed to convert the rotational force into a translational force that is transmitted through the guide slot to actuate a translation of the actuated end of the shank body to thereby move the shank body between fetching and thread cutting positions.

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: 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: In a sewing machine, a control device is configured to execute a needle thread cutting operation including driving a movable cutting blade to a predetermined pivot location, driving a wiper driving mechanism for protruding a wiper by a predetermined stroke, driving the thread take-up driving mechanism to lower the thread take-up by a predetermined distance, driving a wiper driving mechanism to draw back the wiper by a predetermined amount corresponding to the lowering of the thread take-up, driving the movable cutting blade to a standby position, driving the thread tension adjusting mechanism to release a thread tension adjusting mechanism, and driving the thread take-up driving mechanism to move the thread take-up to an original uppermost position.

Abstract: In a sewing machine having an automatic thread cutting mechanism, a situation of a thread cutting operation is detected in power-OFF to continuously carry out a proper operation when a power supply is turned ON again after sudden power-OFF. In a sewing machine having an automatic thread cutting mechanism, there is provided means for detecting an operation situation of the automatic thread cutting mechanism when a power supply is turned ON. Based on a signal for the detection, the automatic thread cutting mechanism is operated to complete a thread cutting operation and to carry out a control to return into an initial state when a stop is performed with the thread cutting mechanism in power-ON executing the thread cutting work.

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 sewing thread spool having thread locking and cutting functions is disclosed. The sewing thread spool comprises a winding core having an outer rim at one end and a bobbin at one end of the core, with a thread cutting plate arranged on an end plane of the bobbin. The bobbin comprises a thread-passing notch arranged at the end with the thread cutting plate. The thread cutting plate comprises a first and a second bayonet sockets separated from each other, the first bayonet socket cooperating with the thread-passing notch to produce a tension in a thread, and the second bayonet socket being used for cutting the thread and fixing the thread end. The thread spool is beneficial in that it cuts the thread and locks it to the spool.

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: Disclosed is an automatic thread cutting device for a sewing machine which is provided with a horizontal loop taker, wherein a thread catching member (4) is operated in response to a thread cutting instruction to reciprocatingly move with a movable blade (5) along a predetermined course, the thread catching member (4) normally catching the upper thread when moving in the return-way of reciprocation to guide the upper thread to a fixed blade (14) which is provided to cut the upper thread in cooperation with the movable blade (5), and wherein a thread regulating means is provided to cut the lower thread (29d) together with the upper thread, the thread regulating means being operated to press down the lower thread (29d) to a position where the lower thread (29d) is caught by the thread catching member (4) in addition to the upper thread when the thread catching member (4) is moving in the return-way of reciprocation.

Abstract: A two-thread lock-stitch sewing machine with a thread cutter comprises a shaft which is parallel to the vertical axis of a shuttle and has a lever arm with a thread pulling knife disposed on it. The bobbin case in the shuttle has a holding finger which is directed toward a stitch hole and is held between two cams that are arranged on a rib. Formed between the cams and the workpiece bearing plate is an interspace which the lever arm passes through, together with the thread pulling knife projecting into a space between the motion travel of the sewing needle and the cams so that a thread cutting operation is enabled to be performed with very short thread tail pieces remaining on the lower side of the workpiece. The thread cutting operation excels by simple design and reliable operation.

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: Thread-cutting device for an eyelet buttonhole sewing machine, having a looper support (70) which can rotate about a vertical axis (22) and is fitted with mutually independently operable thread-cutting tools (42, 53) for a looper thread (60) and a needle thread. Provided on the looper support (70) are drive devices in the form of pneumatic cylinders (29, 30) for the thread-cutting tools (42, 53), which drive devices can be fed compressed air from a stationary compressed air source via a device (69) in the form of elastic hoses (33, 37) or of a rotary bushing. The thread-cutting device according to the invention permits the thread-cutting tools (42, 53) to be operated irrespective of the rotary position of the looper support (70).

Abstract: A holing sewing machine including a workpiece-presser elevating and lowering mechanism which elevates and lowers a workpiece presser, a needle-thread cutting mechanism which cuts a needle thread conveyed by a sewing needle; a bobbin-thread cutting mechanism which draws a bobbin thread from a bobbin and cuts the bobbin thread, an interlocking mechanism which mechanically interlocks the elevating and lowering mechanism, the needle-thread cutting mechanism, and the bobbin-thread cutting mechanism, with one another, such that the elevating and lowering mechanism elevates the workpiece presser after the needle-thread cutting mechanism cuts the needle thread and the bobbin-thread cutting mechanism cuts the bobbin thread, a drive source which drives the interlocking mechanism to operate the workpiece-presser elevating and lowering mechanism, the needle-thread cutting mechanism, and the bobbin-thread cutting mechanism, the drive source being controllable with respect to a speed of operation thereof to drive the inter

Abstract: An automatic thread cutting device for cutting upper and lower threads in motorized and/or computer-operated embroidery and sewing machines. The thread cutting device includes a fixed knife for the upper thread and a movable knife for the lower thread. The movable knife includes a deflector for making the upper thread taut and cutting surface for actually cutting the lower thread. After the lower thread is cut, the movable knife is withdrawn and the upper thread is relaxed so that it can be cut by the fixed knife.

Abstract: The device includes cutting of the needle and hook thread while forming short fabric-side thread ends in a double-thread lockstitch sewing machine with a hook rotating in a horizontal plane under a needle plate. A thread catch device with a cutting edge is provided. A knife is provided cooperating with the cutting edge and with a thread clamp for the hook thread.

Abstract: A sewing machine, in particular a buttonhole sewing machine, is equipped with needle-thread-clamping scissors which have a lower half provided with a cutting edge at its tip portion. They further have an upper half pivotal relative to the lower half and having a cutting edge at its tip portion. Further, they have a clamping jaw to be pressed elastically on the tip portion of the upper half for clamping and holding a tail piece of a needle thread. The upper half can be pivoted in such a way that a receiving opening for the needle thread is formed in an opened position of the scissors, whereas, in a closed position, the needle thread is cut and the tail piece of the needle thread is clamped and retained between the upper half and the clamping jaw. The upper half can further take a third position in which the tip portion of the upper half is free from the clamping jaw and the tail piece of the needle thread is released.

Abstract: A sewing machine comprises a holding device, by means of which the front end of the needle thread can be clamped and held. Further, a cutter is available, by means of which the front end of the needle thread can be cut off directly over the workpiece.

Abstract: An embroidery machine having a spindle, a sewing machine motor driving the spindle, and a thread cutting device including a thread cutting motor and a thread cutting mechanism provided with a movable blade driven by the thread cutting motor. The thread cutting motor is provided independently of the sewing machine motor and is driven so that the movable blade is moved in synchronism with the spindle. The movable blade is movable between a maximum pivot positioned farthest from a stationary blade and a stand-by position close to the stationary blade.

Abstract: An apparatus for automatically cutting off thread formations in sewing machines having a longitudinal direction and a transverse direction. The apparatus includes: a needle plate having a surface defining a support plane; a transport plate disposed adjacent the needle plate, the transport plate being displaceable in a plane parallel to the support plane in both the longitudinal direction and the transverse direction; a cutting device disposed adjacent the needle plate for cutting off a thread formation from the sewn item, the cutting device including a stationary lower blade connected to the needle plate and an upper blade connected to the transport plate, the upper blade defining a first recess therein; and a hold-down device disposed adjacent the needle plate and defining a second recess therein and being configured for holding down a sewn item on the needle plate.

Abstract: A thread cutting apparatus including a pair of blades one movable relative to the other to cut a thread, an actuating device including a cam rotatable about an axis line, and a cam follower which is movable to an operative position where the cam follower follows the cam to move the movable blade to cut the thread, and an inoperative position where the cam follower does not follow the cam, a biasing device which provides a biasing force to bias the cam follower toward the inoperative position, a first movable member which is operatively engaged with the cam follower and which is movable to a first position, and a second position to move the cam follower to the operative position against the biasing force of the biasing device, a second movable member which is movable between a third and a fourth position and which engages, when being moved from the third position to the fourth position, the first movable member to move the first movable member to the second position, and a rotary member which is rotatable with

Abstract: The method and apparatus for preventing seam from raveling in a double chain stitch sewing machine of the invention are applied mainly in sewing of cloth by a double chain stitch sewing machine with multiple needles, and when nearing the end of sewing for forming a double chain stitch S by collaboration of a plurality of needles 5, 6 and a looper 3, a looper thread 10 consecutive from the cloth W to the looper 3 is engaged with a hook 15, and in this state, consequently, needle threads 8, 9 consecutive to the needles 5, 6 from the cloth W through the looper 3, and the looper thread 10 consecutive to the looper 3 from the cloth W are cut off, and the looper thread 10 engaged with the hook 15 is also cut off simultaneously or before or after this cutting, and therefore the looper thread 10 consecutive to the sewing end of the cloth W is set in discontinuous state, and raveling of sewing thread is securely prevented, while the length of the thread end consecutive to the sewing end is shortened, so that a sewn pr

Abstract: A thread cutting device in a sewing machine includes a movable knife which is movable across a space between a throat plate and a shuttle positioned below the throat plate so as to perform a thread cutting operation. A lower thread retreating lever is movable from a waiting position to an operative position for retreating a lower thread taken out from the shuttle to a position out of a thread cutting orbit of the movable knife. The thread cutting device is operable in either a thread cutting mode for cutting both an upper thread and a lower thread or a thread cutting mode for cutting only the upper thread by selectively positioning the lower thread retreating lever at either the waiting position or the operative position during the operation of the movable knife. An actuator and an interlocking mechanism between the actuator and the lower thread retreating lever are provided for driving the lower thread retreating lever. The actuator and the interlocking mechanism are positioned rearwardly of the shuttle.

Abstract: A thread trimming device for a lockstitch bar tacking sewing machine is equipped with a thread trimming unit comprising a detecting member which is rotatably supported by a sewing machine body and has a detecting portion, a first position detecting means which is fixedly mounted on said sewing machine body in such a way as to be capable of facing the detecting portion of the detecting member and which produces a thread trimming signal for starting thread trimming when the detecting portion approaches thereto and a driving unit for driving a thread trimming cam link in such a way as to bring the contact portion of a thread cam link in contact with the cam surface of a thread trimming cam for trimming a needle and a bobbin threads based on the thread trimming signal. As a result, the mechanical components thereof becomes simple in structure and easy in adjustment, and those relating to the thread trimming operation are improved in durability.

Abstract: When needle threads that move vertically together with a plurality of needles which move vertically to pass through a throat plate positioned on a cylinder bed, and a looper thread that is caused to intertwist with the needle threads by a looper which reciprocates in accordance with the vertical motion of the needles are to be cut, the needles are stopped at the bottom dead point or in the vicinity thereof and the looper thread is cut, and then the needles are stopped at the top dead point or in the vicinity thereof and the needle threads are collectively cut.

Abstract: A thread trimming device for a sewing machine in which a movable knife coupled to a thread trimmer lever by way of a link mechanism is turned to cut sewing threads in cooperation with a fixed knife, the first projection of the thread trimmer lever engaging in the cam groove of a thread trimmer cam, comprises a thread trimmer positive motion bracket having a second projection capable of engaging in the positive motion cam groove of a thread trimmer positive motion cam so as to keep the engagement of the first projection with the cam groove after the second projection thereof engages the positive motion cam groove until it is disengaged therefrom. Since the time of completing the thread trimming can be set by the positive motion cam groove of the thread trimmer positive motion cam, the timing of the thread trimming can be adjusted with certainty. Furthermore, the operating time of the driving means can be remarkably reduced.

Abstract: A movable blade unit in an automatic thread cutting device comprises a plate-like arresting member having an arresting portion for arresting the needle thread and the bobbin thread. A plate-like movable blade provided with a cutting edge cuts the needle thread and the bobbin thread in cooperation with a fixed blade and is disposed under the arresting member. A plate-like guide member is disposed under the movable blade and provided with a guide portion for guiding the needle thread and the bobbin thread arrested by the arresting member into a slit formed in the arresting member. A spacer interposed between the movable blade and the guide member forms a gap for receiving the fixed blade between the movable blade and the guide member. These members of the movable blade unit are easy to form; hence, the movable blade unit can be fabricated at a reduced cost and surely holds and cuts the needle thread and the bobbin thread.

Abstract: A thread-pulling device is fastened on the arm of a sewing machine. The thread-pulling device has a thread clamp that can be opened and closed on the thread, and can be moved toward and away from the sewing machine arm. In operation, the needle thread, which has been pulled off the spool and extends to the sewing needle, is conducted through the thread clamp. After an initial seam has been completed, the thread clamp is closed on the thread and moved to an extended position which is remote from the arm. In this way, a given length of the needle thread is pulled off the spool, thus providing the proper length of needle thread for dependable formation of the first stitch of the following seam. Then, shortly after the start of the following sewing process, the thread clamp is moved back over an intermediate distance toward the sewing machine arm so as to pull back the initial piece of the needle thread that is now hanging down from the back of the material at the start of the seam.

Abstract: A thread cutting mechanism is added to a chainstitch sewing machine, including a trimming plate, fitted on the machine in alignment with the needle and looper and associated mechanism. A guideway in the bottom of the plate, extends along a path crossing the loops of the upper and lower threads. A slide moves in the guideway, and has an arm with a pointed free end extendable from the slide to move in and out of the guideway. Pockets formed along a side of the arm capture portions of the upper and lower threads in the sewing head, preparatory to forming a stitch. The slide is reciprocated when a stitching operation ends, extending the arm out of the guideway, pushing aside the upper thread and adjacent lower thread. The arm at its forward extension aligns the pockets with the upper and lower threads, so they engage within the pockets. When the slide retracts the arm draws the threads between the plate and arm.

Abstract: A double-stitch sewing machine is provided which, in a preferred embodiment, includes a throat plate and feed dog with a needle opening for supporting a material to be sewn, a reciprocating needle to penetrate the material, the needle having an eyelet for insertion of a needle thread, the needle being able to penetrate through the sewn material and carry the needle thread through the needle opening, a rotating hook for pulling on the needle thread after insertion of the needle thread through the needle opening, forming a loop in the needle thread with a first leg of the loop being joined with the sewn material and the needle and a second leg of the loop being joined only with the sewn material, a bobbin carrier mounted within the rotating hook having an adjacent clearance with the rotating hook, allowing the rotating hook to cause the needle thread to be brought underneath the bobbin carrier, the bobbin carrier dispensing bobbin thread in cooperation with the rotating hook pulling of the needle thread, a firs

Abstract: A thread holding device having a thread holding member and a holding force imparting member selectively engageable therewith for holding a leading end portion of a needle thread. The thread holding member and the holding force imparting member are pivotally movable by drive means through linking means. The thread holding member has a first angular rotational position at a position below a sewing needle for trapping the leading end portion of the needle thread, a second angular rotational position at a position beside the sewing needle for holding the thread in cooperating with the holding force imparting member, and a third angular rotational position or a retracted position. When the thread holding member is moved from its second to third angular positions, the needle thread leading end is released from the thread holding member.

Abstract: In a thread supply device used in a sewing apparatus having a plurality of needles and a looper mechanism, needle threads guided to the needles and a looper thread guided to the looper are cut by a thread cutting unit at a cutting position, which is off a thread supply path, after a sewing operation is finished but before the following sewing operation starts. The thread supply device comprises a supply mechanism, a stopping mechanism, a memory and a control unit. The supply mechanism forcibly supplies the needle threads and the looper thread. The stopping mechanism stops the threads from being supplied. The memory stores an extra length of each thread, which is required for a cutting operation. The control unit reads out the extra length from the memory and controls the supply mechanism and the stopping mechanism so that each thread is supplied in the extra length.

Abstract: A sewing machine incorporates a needle bar disconnecting mechanism (3) and a thread cutting mechanism (9). The needle bar disconnecting mechanism (3) is interposed between an arm spindle (2) and a needle bar (4), which normally transmits rotations of the arm spindle (2) to the needle bar (4) to vertically move the latter up and down but disconnects the needle bar (4) from the arm spindle (2) to stop the vertical movement of the needle bar (4) when actuated. The thread cutting mechanism (9) cuts threads at the termination of stitching. A rotational phase detecting mechanism (11) is provided for detecting a rotational phase of the arm spindle (2). An electronic control circuit (12) actuates the needle bar disconnecting mechanism (3) when the rotational phase detecting mechanism (11) detects that the arm spindle (2) has reached a predetermined rotational phase after the thread cutting mechanism (9) is actuated.

Abstract: A pattern sewing machine provided with a thread trimmer and a thread delivery unit. After a series of patterns is completed and the thread trimmer trims thread, the thread delivery unit is prohibited from delivering thread until the next sewing operation starts to form another pattern. When the patterns are distant from each other, a needle bar is disconnected and fabric is fed a distance in a non sewing operation. No excess thread is delivered corresponding to the feeding distance of the fabric, thus preventing thread from being wasted. Furthermore, an operator can avoid the cutting of excess thread with scissors. The sewing efficiency is thus enhanced. In the pattern sewing machine the crossover thread connecting the patterns is automatically cut regardless of the distance between the patterns.

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 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: Apparatus and method for severing the needle and looper threads of a chain stitch formed by a sewing machine having an in-line looper system. The 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 stationary knife, a spring positioned below the stationary knife and biased in a direction toward the stationary knife, and a movable knife slidably mounted between the stationary knife and the spring which yieldingly urges 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. These three elements cooperate to hook and sever the needle side of the needle loop and the looper thread below the needle plate and prepare the looper thread for the next stitch.

Abstract: A thread cutting mechanism for a lock stitch sewing machine which comprises a stationary blade, a reciprocally movable blade, operation means for moving the movable blade reciprocally and adjusting means for adjusting the reciprocal movement distance of the movable blade so as to vary the operative position with the initial position maintained constant. The movable blade includes a thread handling portion, a thread cutting knife portion, a thread arresting portion and a thread guide portion.

Abstract: A mechanism for trimming the thread on a sewing machine with a laterally oscillating needle has devices for shifting the amplitude of needle oscillation to a center or zero position and for cutting both needle and bobbin threads. Thread connected to a workpiece is easily cut by actuation of the shift device to move the needle to the center position at which time the thread cutting device is actuated to cut the sewing machine needle and bobbin threads.

Abstract: A device is disclosed for pulling out and cutting off the needle and looper threads in a sewing machine with a delivery roller for delivering material to the machine sewing station. The delivery roller is driven over a first drive, which is dependent on the sewing machine main drive and over a second drive, which is independent of the sewing machine main drive. On the looper of the sewing machine is secured a cutting blade for the needle thread. Furthermore, a needle thread clamp is provided. In order to manage, with a single means for pulling out the needle and looper threads by different lengths, a cutting device for the looper thread is arranged between the cutting blade and the delivery roller, with a guide which is traversed by a thread inlet groove and with a counterknife for a thread severing knife that moves transverse to the material feeding direction. The delivery roller is driven over the second drive for pulling out the threads.

Abstract: A buttonhole machine has a vertically reciprocal needle, a horizontally displaceable material support plate, a rotary stitch plate below the needle, mechanism for feeding a lower thread up through the stitch plate, clamps for holding material on the material plate at the stitch plate, and a drive for rotating the stitch plate in one rotational sense, simultaneously displacing the material plate, and reciprocating the needle to form a buttonhole in the fabric and for rotating it in an opposite return rotational sense after formation of the buttonhole. Such a machine also feeds an upper thread down through the needle to the stitching location and also normally lays a thick cording thread into the buttonhole to reinforce it. This machine is equipped with a feed arm carried by and jointly rotatable with the stitch plate, engaging the lower thread, and pivotal for freeing a length of the lower thread and feeding same to the stitch plate.

Abstract: A horizontal axis loop taker is actuated by a loop taker shaft supported in an eccentric opening in a rotatable bearing located immediately adjacent the loop taker. In a first position of the rotatable bearing, a sewing needle may extend through an orifice in a throat plate to cooperate with the loop taker in the formation of stitches. In a second position of the rotatable bearing achieved by rotating the bearing in a direction to locate the eccentric opening, and thereby the loop taker, further from the throat plate, the sewing needle will not cooperate with the loop taker. The increased clearance thus provided between the loop taker and throat plate will more readily accommodate thread severing devices.

Abstract: A thread cutting device for a sewing machine that will cut threads in a scissor-like action. The device is mounted on a sewing machine pressure arm and can be manually operated. The device comprises a stationary horizontal cutting blade; a pivoting cutting blade is attached to the stationary blade so as to form a cutting field and a finger pressure assembly, having a tensioning means, creates a scissor-like action in the cutting field.

Abstract: A single-operation cam mechanism includes a cam body with a cam surface extending along the body from an entrance location to an exit location. A cam follower is retained in a waiting position adjacent a part of the cam body at which the exit location is found. When the cam follower is moved free of the retainer, a spring forces the cam follower to the part of the cam where the entrance location is found. Then, as the cam rotates, the cam surface engages the follower and forces it back through the exit location and past a resilient trap to the waiting position. The trap snaps shut after the follower has been forced past it, and the surface of the trap then prevents the follower from moving back into engagement with the cam surface except by way of the entrance location. In an underbed thread trimmer, a support member for the cam follower engages a pin connected to blade-like members, some of which have hooks, to carry one set of such members to a position in which their hooks engage looptaker thread.

Abstract: A sewing machine is provided with a needle thread cutting device for severing the free end of the needle thread extending through the eye of the needle at the beginning of a sewing operation to prevent entanglement of the free end with the stitches being formed. A cutter element is mounted for oscillating movement in conjunction with the raising and lowering of the presser foot. The lower end of the cutter element is provided with a transverse leg extending across the upper surface of the presser foot in close proximity thereto rearwardly of the needle. The transverse leg portion is provided with a cutting edge on the side thereof remote from the needle.

Abstract: The sewing machine includes a reciprocating needle bar with a thread-engaging needle which cooperates with a rotatable looper carrying the looper thread which is driven by a rotatable looper drive shaft. The construction includes a thread knife and a thread clamp mounted adjacent the looper and a catcher mounted on a catcher shaft for rotation therewith selectively in the same direction of movement as the looper toward engagement with the knife and in an opposite return direction. The construction includes an improved control member for operating the catcher which is freely rotatable on the looper shaft and is axially displaceable therealong between an operative position and an inoperative position spaced axially from the operative position. A coupler is provided between the control member and the looper shaft which includes a driver having a rod portion which extends in a groove of the control member. A biasing spring biases the control member into an operative position.