Abstract: A buttonhole sewing machine comprises a top arm (1) with a needle (6) movable in up and down reciprocation and a base plate (2). A buttonhole cutting device (13) is provided, having a knife (36) which is disposed on the base plate (2) and comprises a straight cutting edge (37) that extends in the y direction and an eye cutting edge (38). A cutting block (15) cooperates with the knife (36). The knife (36) and the cutting block (15) are motor-adjustable one in relation to the other in the y direction.

Abstract: A buttonhole sewing machine for producing buttonhole seams with seam end sections of various shapes in a work piece comprises an input equipment for feeding buttonhole parameters; and a computer for calculating, from the buttonhole parameters, sewing data that determine the respective buttonhole geometry. It further comprises a memory for storing the computed sewing data and a key to be shifted into two key statuses, by means of which to trigger conversion of a buttonhole seam from a position to the left to a position to the right or vice versa, and storage thereof.

Abstract: A CNC controlled buttonhole sewing machine comprises work piece clamps with sliding drives for displacement from an initial position of spread, by a length of spread, into a final position of spread. The sliding drive is an electric positioning motor that is allocated to a work piece clamp. Further provision is made for a control unit with data storage, in which to store data, for displacement of the work piece clamp by a given length of spread.

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 for the production of buttonholes on a work-piece comprises a thread feeding mechanism on the path of a needle thread which is fed in a direction of delivery. The thread feeding mechanism comprises a pivotal thread lever which has an opening for the needle thread to be led through. Further, the thread level is drivable by a triggerable positioning motor to pivot between a zero position and several positions of thread extraction.

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 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.