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: An eyelet buttonhole sewing machine has a housing with a stand and an arm. A table for carrying an article being sewn is driven in two mutually perpendicular directions (x, y) on the housing. A clamp for the article being sewn is fastened on the table. A needle bar which is mounted in the arm, is driven so as to move up and down and has a needle at its lower end. The clamp for the article being sewn has two arms fastened on a pedestal connected to the table, each arm having a clamping plate provided to bear on the article being sewn. The fastening points of the two arms on the pedestal are substantially adjacent to one another, and both arms are angled in such a manner that their fastening points are offset to the same side of the longitudinal axis of the arm.

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 having a machine arm, a rest for the material being sewn and a device for producing buttonholes, which comprises a cutting knife and a plurality of cutting blocks of respectively different lengths which are arranged on a common carrier. The buttonhole device is acted upon by an actuating device that can be moved from an upper position into a lower position, the cutting knife is arranged in a stationary manner underneath the sewing material, and the cutting block is lowered by the actuating device onto the cutting knife.

Abstract: A thread-cutting mechanism for a sewing machine (2), especially an eyelet-buttonhole sewing machine with a moving blade (12 or 12") and a stationary blade (16). The moving blade travels back and forth in a groove (19) in a plate (1) with an aperture for the needle to pass through while it is producing a stitch. The needle-aperture plate comprises at least a top (11 or 11") and a bottom (10 or 10"). The moving blade is entirely accommodated between the top and the bottom of the plate. The stationary blade is part of the top.

Abstract: An eyelet buttonhole sewing machine has a suction device between the throat plate and the wedge-shaped knife of the buttonhole cutting device. The suction device includes a suction tube and is connected to a vacuum generator, for instance an ejector nozzle or a transvector nozzle. The looper thread is brought near the suction device by a thread puller. When the looper thread is cut by the thread cutting device at the end of the sewing process, suction is applied to the suction tube, pulling the end of the looper thread into the opening of the suction tube. In this way, the looper-thread end assumes a well defined position in which it is disposed for being completely covered by the corresponding welt of the following buttonhole to be sewn. With the suction device and thread puller operating as described, it is no longer necessary to clean the buttonhole by cutting off the end of the looper thread.

Abstract: The disclosure concerns a drive device for a double thread chain-stitch buttonhole sewing machine. The machine has a first drive shaft for driving the sewing needle and for moving the cloth support plate for sewing. It has a separate worm shaft for moving the cloth support plate to the sewing position and also for operating a knife for cutting the buttonhole. A first respective electromagnetic clutch operates the sewing needle drive shaft, and a second respective electromagnetic clutch operates an intermediate shaft which then operates the worm shaft for operating the cloth support plate and knife operating shaft are provided. A drive shaft is connected with the armature part of the first electromagnetic clutch on the sewing needle driving shaft. That armature part is gear connected with an armature part of the second clutch on the intermediate shaft.

Abstract: A thread-holding device is used with a standard buttonhole machine having a support head, a stitching needle for a needle thread displaceably mounted on the support head, and a blade for cutting the needle thread after a stitching operation and forming thereon a free end extending laterally from the needle. The thread-holding device comprises a support plate pivoted on the head, and a thread clip having a pair of jaws displaceable between a closed position engaging each other for holding the thread and an open position for releasing it. An actuator on the support plate and carrying the thread clip can move same vertically between an upper position spaced laterally relatively far from the needle and a lower position laterally relatively close to the needle.

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.