Abstract: Disclosed is a sewing machine which evaluates sewing quality using a stitch tightness index. During sewing operation, a used length of an upper thread per stitch is detected, and a stitch tightness index per sewn stitch is calculated on the basis of a stitch length per stitch defined by sewing pattern data, a fabric thickness of a sewing workpiece, and detected data of the used length of the upper thread. Then, notification is made which corresponds to the calculated stitch tightness index per sewn stitch (such as a visual display of the stitch tightness index). After that, acceptability/non-acceptability of the thread tightness per sewn stitch can be determined by comparing the calculated stitch tightness index per sewn stitch against a reference value, and a result of the determination can be notified.

Abstract: A needle bar case has a plurality of needle bars. As a main shaft is rotated by a main shaft motor (first drive source), the needle bars are driven in an up-down direction so that a sewing operation is carried out in a conventionally-known manner. Ascending/descending bars are supported on the needle bar case in corresponding relation to the needle bars, and each of the ascending/descending bars is driven in the up-down direction by a motor (second drive source). A cord guide member for guiding a cord material onto a workpiece is mounted to the lower end of any of the ascending/descending bars, in place of a conventional presser foot. Cord sewing or loop sewing of cord material can be performed selectively by changing an ascending/descending stroke of the ascending/descending bar. Thus, cord sewing and loop sewing of the chord material can be performed selectively with a simple construction.

Abstract: A single bead-shaped piece fed from a storage pipe storing therein a large number of bead-shaped pieces is carried not on a bearing plate but on a support member provided independently from the bearing plate. The support member is arranged movable on the bearing plate in conjunction with forward and backward movement of a feeding member, and also arranged to be moved relative to the feeding member at the time of the forward or backward movement thereof. The support member is provided with a clamping section for clamping the bead-shaped piece, which is adapted to clamp the bead-shaped piece in conjunction with the relative movement of the feeding member and the support member. This permits the bead-shaped piece to be delivered properly from the storage pipe to the sewing position in a stable manner, and hence a sewing machine can reliably sew the bead-shaped piece on a sewing material.

Abstract: A guide is mounted to a rotary member which is freely rotatable about the axis of a needle bar, and guides a sewing material to a needle drop position of the sewing needle. A cutter device is mounted to a side of the rotary member opposed to the guide in such a manner that the cutter device is rotatable together with the rotary member for cutting the sewing material, having been paid out from the guide, at a predetermined cutting position. A retention mechanism is incorporated in the cutter device for retaining an end portion of the sewing material, at a position closer to the guide than the predetermined cutting position and in interlocked relation to cutting, by the cutter device, of the sewing material. Thus, upon restart of sewing of the sewing material, the retention mechanism retains an end portion of the sewing material.

Abstract: Sewing machine includes, in association with each thread take-up levers: a thread take-up member provided on the front surface of a support member cover and having a thread take-up spring; a prevention member for preventing a thread, put on the thread take-up spring, from flowing rearward; a cover member provided in front of the thread take-up member and independently detachable in a forward direction; and a guide section having a valley portion formed therein for receiving therein a distal end portion of the thread take-up spring and movably guiding the received distal end portion. The cover member has a lower end portion opened to permit insertion therein of a thread and is constructed to guide the thread from the lower end portion to the thread take-up spring. The cover member may further include a guide wall for guiding the thread from the lower end portion to the thread take-up spring.

Abstract: An inner rotary hook has a needle drop hole, and side wall portions formed over the drop hole and defining a space for passage therethrough of a sewing needle. The side wall portions are located adjacent to opposite sides of the needle passing through the space and extend from a region in front of the needle to a region behind the needle. The side wall portions can abut against an upper thread, passed through a hole of the needle, near a bottom dead point of the needle. If any of two portions of the thread located forward and rearward of the needle has strayed laterally, it can abut against one of the wall portions. Consequently, it is possible to prevent the front-side upper thread portion from circling around behind the needle, but also prevent the rear-side upper thread portion from straying laterally to form a laterally-protruding loop.

Abstract: A cutting mechanism for cutting off a leading sequin from a continuous sequin strip in response to sewing operation is constructed to cut off the sequin at substantially the same time as a sewing needle pierces a sewing workpiece. For example, the cutting mechanism includes a movable cutter blade, and an abutting member that, in response to sewing operation, abuts against the movable cutter blade to move the movable cutter blade in a predetermined direction so that the sequin is cut off by the movable cutter blade. The abutting member is provided in a presser foot that presses down the sewing workpiece in interlocked relation to the sewing needle during the sewing operation.

Abstract: A holding frame includes upper and lower frame members having substantially the same thicknesses, and an inner frame member detachably attachable to the inner peripheries of the upper and lower frame members. The upper and lower frame members are fixed together in vertically superposed relation to each other with a workpiece sandwiched therebetween. The workpiece can be set on the frame in any desired of a first stretched-taut state where the workpiece is stretched taut and generally flush with the upper surface of the upper frame member by being pressed upward via the inner frame member, and a second stretched-taut state where the workpiece is stretched taut and generally flush with the lower surface of the lower frame member by being pressed downward via the inner frame member. The workpiece can be held on the frame with substantially the same degrees of tautness in the first and second stretched-taut states.

Abstract: A pulling device is configured to grip, after cutting of a sewing material, a suitable portion of the sewing material by means of a grip member, where a leading end portion of the sewing material having been pulled out from a guide device, and pull back the sewing material by movement of the grip member having the sewing material gripped thereby. Thus, the leading end portion of the sewing material, pulled out and extending from the guide device more than necessary, can be minimized to a length necessary for the sewing material to be reliably sewn onto a sewing object at an initial stage of a next sewing operation. In this way, it is possible to minimize a length of a portion of the sewing material that was heretofore wasted without being sewn onto the sewing object.

Abstract: A guide member is moved in interlocked relation to a rotary member rotating about the axis of a needle bar, so that a string-shaped material paid out from a bobbin is guided to a needle drop position of a sewing needle. The bobbin having the string-shaped material wound thereon is supported by a support member that is rotatable generally about the axis of the needle bar and disposed over a machine table in such a manner as to not hamper movement of an embroidery frame. The bobbin can be positioned at a distance from a machine head; thus, bobbins of increased sizes can be used. The support member is controlled in orientation, by means of a drive source, in accordance with rotation of the rotary member. The bobbin itself revolves around the machine head, which allows the string-shaped material to be constantly appropriately guided to the needle drop position.

Abstract: Distal end section of a heat cutter is movable among a processing position where the heating distal end section is kept pressed against a workpiece, a standby position located away from the workpiece, and a refracted position located farther away from the workpiece than the standby position. Pressing member is movable between an operating position where the pressing member presses down the workpiece and a non-operating position where the pressing member does not press down the workpiece. The distal end section is moved between the standby position and the retracted position in interlocked relation to the movement of the pressing member, and, while the pressing member is in the operating position, the distal end section is moved between the standby position and the processing position. Thus, appropriate processing can be performed even at start and end points of the processing.

Abstract: Decorative elements are sewn, with a first-type sewing thread, to a base member in accordance with a first pattern. One surface of the base member is covered with a see-through cover member, and an embroidery sewing operation is performed on the superposed base member and cover member. Then, the sewing thread, sewing the decorative elements on the base member, is removed from the base member. The embroidery sewing operation is performed in accordance with a second pattern surrounding the decorative elements sewn on the base member in accordance with the first pattern. Thus, the decorative elements are freely movably accommodated in a space defined between the base member and the cover member, so that they can freely move within the space in response to movement of the base member. Such a decorative design with the movable decorative elements can be made on the base member easily and efficiently.

Abstract: Pattern data of an embroidery pattern includes data of given points for defining plural positions associated with the embroidery pattern as reference positions for pre-movement of the embroidery frame and distance data that indicates respective distances between the respective given points and a predetermined starting point. Before embroidering or trace is started, any one of the given points is specified or selected, and the embroidery frame is moved to the reference position associated with the selected given point through manual operation of a switch. When the embroidering or the trace starts, the embroidery frame is automatically moved from the selected reference position to a position corresponding to the starting point of the embroidery pattern on the basis of the distance data between the specified given point and the starting point, and then the embroidering or the trace is started from the position corresponding to the starting point.

Abstract: A single bead-shaped piece fed from a storage pipe storing therein a large number of bead-shaped pieces is carried not on a bearing plate but on a support member provided independently from the bearing plate. The support member is arranged movable on the bearing plate in conjunction with forward and backward movement of a feeding member, and also arranged to be moved relative to the feeding member at the time of the forward or backward movement thereof. The support member is provided with a clamping section for clamping the bead-shaped piece, which is adapted to clamp the bead-shaped piece in conjunction with the relative movement of the feeding member and the support member. This permits the bead-shaped piece to be delivered properly from the storage pipe to the sewing position in a stable manner, and hence a sewing machine can reliably sew the bead-shaped piece on a sewing material.

Abstract: First calculation section calculates, on the basis of sewing data, a sewing-progressing direction angle for rotating a rotary cylinder to orient an embroidering material, guided by a guide lever of a zigzag sewing head, in a sewing-progressing direction. Second calculation section adds or subtracts a zigzag-swinging angle to or from the sewing-progressing direction angle to thereby calculate a target rotational angle of the rotary cylinder. Swinging mechanism may be provided for swinging the guide lever relative to the rotary cylinder, and a swinging amount corresponding to the swinging angle of the rotary cylinder may be added to a width of zigzag-swinging by the swinging mechanism. Alternatively, every swinging movement necessary for zigzagging the embroidering material may be set by the swinging angle without the guide lever being caused to swing relative to the rotary cylinder.

Abstract: Rotary hook drive device for a sewing machine includes: a rotary hook rotatably provided on a rotary hook support; a cylindrical grooved cam provided on a drive shaft drivable to rotate in one direction; a cam follower engaged in a cam groove of the cylindrical grooved cam and capable of making reciprocative movement about a support shaft in response to rotation of the cylindrical grooved cam; and a transmission mechanism that transmits the reciprocative movement of the cam follower to the rotary hook to cause the rotary hook to make reciprocative pivoting movement. Such arrangements can prevent deviation in driving timing of the rotary hook and simplify the construction of the rotary hook drive device.

Abstract: A balancer is fixedly attached to a rotary input shaft of a crank mechanism that converts rotary drive of a needle bar drive source to up-and-down motion of a needle bar. The balancer is caused to rotate at substantially an opposite phase with respect to up-and-down motion of the needle bar with the rotary drive of the needle bar drive source. When the balancer is driven at substantially the opposite phase with respect to the up-and-down motion of the needle bar, inertia force in an up-and-down direction of the needle bar, generated due to the up-and-down motion of the needle bar is negated, whereby it is possible to reduce vibration generated in the up-and-down direction. Sewing heads paired with each other by being arbitrarily combined are controlled so as to be rotationally driven to cause rotational directions of the needle bar drive sources to become opposite directions to each other.