Abstract: Since a solenoid device generates the maximum drawing force at the final position of the retracting stroke of a plunger when it retracts into the solenoid device, the drawing force becomes so large at a position close to a pressing end position of a pressing member that energy is consumed than necessity, and the solenoid device is made large-sized. Accordingly, an arch clamp foot lifting apparatus of the present invention solved this problem by connecting a wedge-shaped block member to a plunger of the solenoid device and retaining an upper portion of the pressing member on a cam surface of a block member through a driven portion.

Abstract: When arch clamp feet are replaced with other, set screws fastening a retaining plate are all removed, and the same set screws are fastened again to the retaining plates after the replacement of the arch clamp feet, which takes time and labor. Accordingly, the replacement of the arch clamp feet involved in the change of working process in a sewing mill, causes the deterioration of the rate of operation. A arch clamp foot pressing device is provided with a carrying unit which moves arch clamp foot lifting levers substantially horizontally along axes connecting between tip end portions and base end portions of the arch clamp foot lifting levers while it is guided by a pin, wherein the arch clamp foot lifting levers are moved in the direction of the base end portions by the carrying unit so that the tip end portions of the arch clamp foot lifting levers are disengaged from slots of arch clamp feet.

Abstract: A clamp for a buttonhole sewing machine includes two curved cantilevered arms which arch forward and downward to parallel feet portion. The clamp is supported on an extension of a movable clamping plate and moves with the clamping plate. A lever compresses a spring, pushing the clamp into firm engagement with the workpiece on the movable clamping plate. A detent holds the spring compressed and the clamp engaged until the end of the cycle, when the detent is released and the spring pushes the clamp upward so that the workpiece may be moved.

Abstract: A feed mechanism for a buttonhole sewing machine has a movable plate with a clamped piece of cloth. A rack is formed on a rearward extension of the plate. A pinion engages the rack, and a large gear is fixed to the pinion. An upper driving gear drives the large gear and is fixed to a vertical stub shaft which extends through the base of the sewing machine. A lower driving gear is mounted on the lower end of the vertical stub shaft beneath the work-supporting surface. A longitudinally shiftable horizontal shaft is mounted beneath the vertical stub shaft. A left bevel gear and a right bevel gear are keyed to the shiftable shaft. The shaft may be shifted so that either one or the other bevel gear engages the gear on the vertical stub shaft, or to an intermediate position in which the bevel gears are disengaged. The horizontal shaft is driven by a ratchet mechanism.

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: At a work clamp for buttonhole sewing machines, comprising a support plate and a clamping frame arranged at a pivotable carrying lever, spaced from the clamping frame, a hold-down device with a clamping plate resiliently pressed against the work is fastened at the carrying lever. The clamping frame, when raised is pressed into a slanting position by a spring. During the descending movement of the clamping frame and hold-down device, the hold-down device precedes the clamping frame and clamps the work to the support plate. As a next step, the edge of the clamping plate of the clamping frame which is spaced from the hold-down device impinges on the work. A clamping surface of the clamping plate forms an acute angle with the support plate. As the descending movement of the clamping plate continues, the clamping frame swings out about its bearing pin on the carrying lever. At this time the edge engaging the work moves away from the hold-down device.

Abstract: The cloth clamp comprises a pivot arm provided with a clamp foot, which arm can automatically assume a closed position through a toggle lever drive, a setting lever connected therewith, and an extension spring acting on the setting lever counter to the force of a leaf spring packet acting on the toggle lever drive. An actuating mechanism is needed only for opening the cloth clamp.

Abstract: A low inertia drive mechanism for imparting movement to a fabric clamp with respect to the needle of a sewing machine. The drive mechanism comprises a first table mounted for translation in a first straight path, a second table mounted for translation independent of said first table in a second straight path perpendicular to said first straight path, and a third table to which the fabric clamp is attached is slidably mounted on transverse rods carried in the second table. Drive means comprising separate motors for the first and second tables is provided for imparting movements, whereby the third table may partake of translation movement in any direction.Also disclosed is a fabric clamp for supporting and guiding fabric to be sewn in cooperative disposition with respect to the needle of a sewing machine, for use with a variable translation fabric feeding mechanism. The clamp includes upper and lower supporting structures.

Abstract: A sewing machine for sewing buttonholes in a workpiece comprises a stationary lower part and an arm having one end pivotally mounted on the lower part and having an opposite end which carries a rotary hook which cooperates with a reciprocating needle carried in the lower part. The arm is pivotal relative to the base part to move the arm from a fixable sewing position with said hook spaced by a predetermined distance from the needle at a stitch-forming area to a rest position in which it is spaced away from the stitch-forming area. A thread-monitoring device is located adjacent the needle for monitoring the thread and detecting any breakage thereof. The machine includes a buttonhole cutting mechanism which is connected to the drive means so as to periodically cut the workpiece. A clamp is carried by the upper arm and it has a lower portion which rests on a resilient support which is biased upwardly by a spring.

Abstract: A finger mounted on the work engaging plate that interlocks with the work engaging presser foot of a buttonhole sewing presser device to effectively prevent travel of the work engaging shoe when the presser foot is raised for work insertion. In addition the finger will prevent accidental disengagement when the buttonhole sewing presser device tilts after the presser foot has been raised.

Abstract: This invention relates to a device for selectively actuating the workpiece clamp of an automatically controlled bar tacker sewing machine utilizing electrically operated pneumatic cylinders operatively connected to the upper clamping element to cause release of the workpiece. The clamp feet are releasably independent of other sewing operations. The upper clamping plate and the feed plate are secured to the clamp assembly by quick change fittings.