The present invention relates to a structure for fastening composite structures, and more particularly, to a sewing machine for stitching composite materials which is capable of automatically and continuously stitching the composite structures by using a high-rigidity fiber in order to laminate and join the composite materials. The sewing machine for stitching composite materials according to the present invention automatically and continuously performs a stitching operation for joining composite materials by using a high-rigidity composite fiber for joining the composite materials, and as a result, it is possible to reduce process time for joining the composite materials and improve productivity.

Apparatuses, methods, and computer program products for quilting webs without compressing the webs. A quilting machine includes a needle bar to which needles are attached, needle thread passing through each needle, a looper shaft to which loopers are attached, a looper corresponding to each needle and from which looper thread is provided to form stitches, and a retainer bar to which spreaders are attached to facilitate stitching. A drive pulley powered by a first servo motor rotates cranks to move the needles through a cycle and rotates a belt which rotates an indexer pulley. Rotation of the indexer pulley oscillates the looper shaft and reciprocates the retainer bar. Another drive pulley powered by a second servo motor operates to move an input web through the machine between chain stiches.

Apparatuses, methods, and computer program products for quilting webs without compressing the webs. A quilting machine includes a needle bar to which needles are attached, needle thread passing through each needle, a looper shaft to which loopers are attached, a looper corresponding to each needle and from which looper thread is provided to form stitches, and a retainer bar to which spreaders are attached to facilitate stitching. A drive pulley powered by a first servo motor rotates cranks to move the needles through a cycle and rotates a belt which rotates an indexer pulley. Rotation of the indexer pulley oscillates the looper shaft and reciprocates the retainer bar. Another drive pulley powered by a second servo motor operates to move an input web through the machine between chain stiches.

A sewing machine includes a thread cutter. The thread cutter includes a cutter blade having a blade edge configured to cut a thread, and a movable member. The movable member includes a guide having a guide surface adjacent to the cutter blade. The guide is configured to receive force from the thread at the guide surface during the course of cutting the thread with the cutter blade and to move in a moving direction which is a longitudinal direction of the blade edge.

An automatic thread trimming device of a sewing machine contains: a holding disc, a cutter assembly, a fixed cutter, and a protective sheet. The automatic thread trimming device further contains an abutting segment formed on a distal portion of a curved section of a front end of an elastic extension and corresponding to a contact zone of a movable cutter, such that the movable cutter moves to the fixed cutter horizontally to produce cutting force. In the meantime, a longitudinal thickness of a protrusion corresponding to a receiving orifice is 0.5 mm so that a short thread end is cut between a thread and a cut portion of the thread, and the short thread end retracts inward because of a woven fabric, thus obtaining a flatness of a sewing product. Preferably, the automatic thread trimming device is capable of being driven by drive elements of any sewing machines.

An automatic thread trimming device of a sewing machine contains: a holding disc, a cutter assembly, a fixed cutter, and a protective sheet. The automatic thread trimming device further contains an abutting segment formed on a distal portion of a curved section of a front end of an elastic extension and corresponding to a contact zone of a movable cutter, such that the movable cutter moves to the fixed cutter horizontally to produce cutting force. In the meantime, a longitudinal thickness of a protrusion corresponding to a receiving orifice is 0.5 mm so that a short thread end is cut between a thread and a cut portion of the thread, and the short thread end retracts inward because of a woven fabric, thus obtaining a flatness of a sewing product. Preferably, the automatic thread trimming device is capable of being driven by drive elements of any sewing machines.

In thread cutting mechanism portions of a lower thread winding device, two groove portions of an inner threading groove portion and an outer threading groove portion are formed on a holder. In the inner threading groove portion, one end portion is opened to one of an intersecting direction intersecting with a radial direction of the holder at an outer peripheral portion of the holder and another end portion is located at an inner side of a small-diameter bobbin in the radial direction. The outer threading groove portion is located at an outer side of the inner threading groove portion in the radial direction of the holder. In the outer threading groove portion, one end portion is communicated with the inner threading groove portion and located at the outer side of a large-diameter bobbin in the radial direction and another end portion is located at the inner side of the large-diameter bobbin in the radial direction.

A chain-off thread cutter for cutting a chain-off thread formed by a sewing machine. The chain-off thread cutter including: a fixed blade; a movable blade that moves toward and away from the fixed blade; a driving unit that drives the movable blade to move the movable blade; a foreign matter detector that detects foreign matter present in a track of the movable blade; and a control unit that stops the driving unit when the foreign matter is detected by the foreign matter detector.

A chain-off thread cutter for cutting a chain-off thread formed by a sewing machine. The chain-off thread cutter including: a fixed blade; a movable blade that moves toward and away from the fixed blade; a driving unit that drives the movable blade to move the movable blade; a foreign matter detector that detects foreign matter present in a track of the movable blade; and a control unit that stops the driving unit when the foreign matter is detected by the foreign matter detector.

A sewing machine including a detection portion that detects a movement amount of a workpiece, a sewing machine motor that serves as a driving source for vertical movement of a needle bar, and a control device that controls the sewing machine motor based on the detection result by the detection portion and performs control to maintain a constant stitch pitch. The control device lengthens a period for obtaining an output of the detection portion when the movement amount of the workpiece per unit time based on the detection result by the detection portion is decreased, and shortens the period for obtaining the output of the detection portion when the movement amount of the workpiece per unit time based on the detection result by the detection portion is increased.