Abstract: A buttonhole sewing machine comprises work piece clamps with a pneumatically actuated displacement drive for displacement relative to each other of the work piece clamps from an initial position of spread by a length of spread into a final position of spread. Only the first work piece clamp is displaceable relative to the x-y table. The displacement of the first work piece clamp is defined between two stop positions. A control unit stores data for triggering an x drive for reversed displacement of the x-y table by half the given length of spread.

Abstract: A buttonhole sewing machine comprises work piece clamps with displacement drives for displacement from an initial position of spread by a length of spread into a final position of spread. The work piece clamp comprises a supporting plate for accommodation of a work piece and a clamping plate mounted on the supporting plate. A clamping drive for actuation of the clamping plate supports itself on the supporting plate.

Abstract: In a buttonhole sewing machine, a sewing mechanism and a feed bracket are controlled to form a buttonhole defined by settings, such as zigzag stitch length, zigzag pitch, bar-tack length, bar-tack pitch, and cutter space. The buttonhole can be set on the operation panel and changed to various shapes by changing the above settings. In particular, the left and right zigzag stitch widths can be set differently, and the front and rear bar-tack lengths can be also set differently. Thus, the balance of the buttonhole can be finely adjusted.

Abstract: A buttonhole sewing machine comprises a needle thread feeding mechanism, in which the needle thread is guided over a cam disk, which performs a rotation during two stitches of the needle. Along its periphery, the cam disk has such a curvature that tensioning and releasing the needle thread complies with the requirements of alternately sewing a single thread chain stitch and a double thread chain stitch during the sewing of a zigzag buttonhole seam.

Abstract: A cloth cutting knife 16 is structured such that the length of the cutting edge thereof is set shorter than the length of the side sewing portions of a buttonhole to be formed, and a buttonhole having a length corresponding to the length of the right and left side sewing portions can be formed by moving up and down the cloth cutting knife 16 two or more times. The cloth cutting knife 16 is moved up and down at least once during formation of the stitches of the right and left side sewing portions. Also, the cloth cutting knife 16 is moved up and down once each time a given number of stitches of the right and left side sewing portions are formed. The given number of stitches is set in accordance with both of the length of the cutting edge of the cloth cutting knife 16 and the length of the buttonhole to be formed.

Abstract: A sewing machine having a table, driven in two directions by two motors and accommodating material to be sewn, sewing tools, and a cutting device for producing a buttonhole in the material to be sewn. The buttonhole is provided with an incision and is bounded by zigzag stitches of a buttonhole bead, running around the incision. The incision is produced either before or after the sewing of the buttonhole bead. The sewing tools include a needle bar, which is driven up and down and also oscillates in the horizontal direction, and a needle, which is provided at the bottom end of the needle bar and interacts with a looper mounted in the base plate. The sewing tools are drivable in a rotatable manner by a third motor. The sewing machine has a control device, from which various buttonhole shapes stored therein can be retrieved, a device for switching from the pre-cutting mode to the post-cutting mode, and a needle-oscillating device driven by a fourth motor and producing the zigzag stitches.

Abstract: A sewing machine with a table (9) driven by two motors (60, 80) in two directions (x, y) and receiving sewing material (36), with sewing implements and with a cutting device (34) for producing, in the sewing material (36), a buttonhole (28) which is provided with an incision (32) and which is delimited by zigzag stitches of a buttonhole bead (26, 27; 26', 27') which run around the incision (32), the incision (32) being produced before or after sewing the zigzag stitches. The sewing implements include a needle bar (4), driven up and down, and oscillating in the horizontal direction to form the zigzag stitches, and a needle (6), which is provided at the lower end of the needle bar (4) and which cooperates with a looper (11) mounted in the baseplate (12). The sewing implements are further driven in rotation by a third motor (13). The sewing machine also includes a control unit (90), which can store various buttonhole shapes and control the other components.

Abstract: A sewing machine has a table, driven in one plane and carrying the material to be sewn, a stitch-forming device and a cutting device for producing a buttonhole in the material to be sewn. The buttonhole is provided with an incision, is produced in the pre-cutting or post-cutting mode and is bounded by zigzag stitches, running around the incision, of a buttonhole bead. The sewing machine has sewing tools comprising a needle bar, which is driven up and down and oscillates in the horizontal direction, and a needle, which is provided at the bottom end of the needle bar and interacts with a looper mounted in a base plate. An adjusting device sets the position of the zigzag stitches being provided in order to provide intermediate material (b) within the buttonhole bead in the post-cutting mode for allowing the material to be cut, without cutting the already-formed buttonhole bead.

Abstract: A sewing machine is provided with an X-correction value input unit that corrects, in an X-direction, seam position with respect to a position of an opening, e.g., a circular hole, formed in a workpiece cloth by an opening forming mechanism, and an X-direction seam data correction unit that corrects seam data based on an X correction value inputted from the X-correction value input unit. The sewing machine can also be provided with an Y-correction input unit and a Y-direction seam data correction unit for correcting Y-direction information in the seam data. With the seam data corrected by the seam data correction units, a seam position can be corrected with respect to the position of the opening formed by the opening forming mechanism.

Abstract: In a sewing machine for creating buttonholes, a selection switch is used to designate whether the hole will be cut first or the buttonhole will be defined by stitching first. In both cases, stitch width remains constant. Where the buttonhole is outlined by stitches first, a needle bar bight line is offset by a distance .DELTA.X from the bight line followed when the buttonhole is cut first. The result of the .DELTA.X offset is a spacing equal to 2.DELTA.X between the inner edges of the stitched buttonhole providing space in which to cut the buttonhole.

Abstract: An automatic cloth feeding device in a cycle sewing machine is provided with first and a second cloth pressers which are placed on a working table and respectively hold and release both ends of the cloth in the lateral direction. Rotary motion of a first rotary shaft is changed to a linear motion by a first converting mechanism to cause the first cloth presser to move laterally while rotary motion of a second rotary shaft is changed to a linear motion by a second converting mechanism to cause the second cloth presser to move laterally. The first rotary shaft and the second rotary shaft are connected with or disconnected from each other by a clutch so that the first rotary shaft is driven by or released from a drive unit.

Abstract: Disclosed is a button-hole sewing machine which includes an electric motor for driving the sewing machine; a machine body including a bed for holding a workpiece in cooperation with a workpiece clamping means; a stitch forming device for working button-holes in the workpiece and including a mechanism for driving a needle bar which supports a needle, a looper-spreader mechanism for driving a looper and a spreader, and a turning mechanism for turning the needle bar, the looper and the spreader. The needle bar driving mechanism includes a vertical reciprocation mechanism and a needle lateral vibrating mechanism; and an arm shaft for driving the up/down moving mechanism.

Abstract: Disclosed is a button-hole sewing machine which includes an electric motor for driving the sewing machine; a machine body including a bed for holding a workpiece in cooperation with a piece clamping means; a stitch forming device for working button-holes in the work piece and including mechanism for driving a needle bar which supports a needle, a looper-spreader mechanism for driving a looper and a spreader, and a turning mechanism for turning the needle bar, the looper and the spreader. The needle bar driving mechanism includes a vertical reciprocation mechanism and a needle lateral and an arm shaft for driving the up/down moving mechanism.

Abstract: A feed drive for a stitch group sewing machine includes a cam plate serving to drive a work clamp. The cam plate is connected to a controllable clutch driven from the drive motor of the sewing machine. In order to keep the stitch length constant at varying lengths of the stitch group, the output speed of the clutch is controllable by a control device as a function of the rotational speed of the sewing machine of the transmission ratio of a gearing between the cam plate and the work clamp which determines the length of the stitch group, and of the adjusted stitch length. The stitch group to be sewn may be divided into two sections having their stitch lengths variable independently of each other, by providing that a switch responsive to a partial revolution of the cam plate corresponding to the length of the first section, alternately connects one of two potentiometers which determine the stitch length, to the control circuit of the clutch.

Abstract: A feed drive for a stitch group sewing machine includes a cam plate serving to drive a cloth clamp and it is connected with a separate motor. In order to keep the stitch length constant at varying length of the stitch group, the motor speed is controllable by a control device as a function of the rotational speed of the sewing machine, of the transmission ratio of a gearing between cam plate and cloth clamp which determines the length of the stitch group, and of the adjusted stitch length. The stitch group to be sewn can be divided into two sections with a stitch length variable independently of each other, in that a path-dependent switch operable after a partial revolution of the cam plate corresponding to the length of the first section alternately connects one of two potentiometers which determine the stitch length, with the motor control circuit.

Abstract: In a zig zag sewing machine, an arm shaft is rotatably supported on an arm thereof and carries at one end a handwheel member. The arm shaft performs a clockwise rotation simultaneous with the clockwise rotation of the handwheel member end. Due to such rotation of the arm shaft, a needle bar is given a reciprocating motion, and also a lateral movement in a plane perpendicular to the axis of the arm shaft. A bed shaft is rotatably supported on a bed parallel to the arm shaft and extending from a position corresponding to the reciprocating path of the needle, in the opposite direction from the arm shaft. A loop taker having a thread seizing rotary hook is mounted to the bed shaft at the corresponding position and rotated synchronously with and in an opposite direction to the rotation of the arm shaft. The thread seizing rotary hook of the loop taker and the bed shaft are positioned on opposite sides of the reciprocating path of the needle.