Abstract: An electro-mechanical actuator for sewing machines which allows settings to be made electrically and then acts upon such settings mechanically using the power from the sewing machine drive. This electro-mechanical actuator utilizes the full cycle of a sewing operation for the setting and positioning of the controlled function.

Abstract: A presser device for a sewing machine having a rockable member pivotably carried by the sewing machine frame and connected to a presser bar to axially move the same up or down, a pivoted lever urged by a spring towards the rockable member, and, a drag link carrying a roller on one end, which roller extends between the pivoted lever and one of two surfaces above and below the pivot of the rockable member to urge the presser bar upwardly or downwardly, respectively. Presser bar pressure is varied by varying the spacing between the roller and the pivot of the rockable member. Two embodiments are disclosed, a first wherein the position of the roller is varied by means of a second pivoted lever connected to the drag link; and, a second wherein a pair of push buttons operate on a bell crank connected to the drag link, one of the push buttons incorporating a cam to control movement of the drag link.

Abstract: A feed regulator shaft lock for a sewing machine operative during the feed of a work material to insure retention of a selected feed against feed back of forces from the feed dogs. A radially functioning cam is supported on a feed shaft in timed relationship to a feed lift cam also supported thereon. A brake member is affixed to a feed regulator shaft, on which a feed regulator is also supported for selective variation thereof by a manual control or by a cam. A shiftable member extending between the cam on the feed shaft and the brake member on the feed regulator shaft may be urged by the cam into pressure contact with the brake member during that portion of the sewing cycle when feed of the work material is effected.

Abstract: A linear motor for use, for example, in sewing machines for controlling needle vibration as to amplitude and/or fabric feed both in magnitude and direction, said motor comprising a frame having an internal central pole piece spaced intermediate two permanent magnets of the high energy product type which are attached to the frame, the central pole piece providing supporting means for movable coil member integrally formed with connecting arms pivotally fastened to an actuator arm carried on a pivoted potentiometer shaft. The permanent magnets are secured through their own magnetism to the frame and are each locked in proper orientation by a non-metallic retainer which is locked to the magnet and additionally formed with a closure panel, said closure panels cooperating with the motor frame completely to enclose a compartment for the movable coil member effecting both a minimum external leakage field and a dust proof unit.

Abstract: A heat sink arrangement for a circuit board in a sewing machine which supports the circuit board for ready disassembly therefrom, and makes use of the sewing machine frame as an additional heat sink. The circuit board is riveted to an aluminum heat sink member which carrys the power transistors in a manner to provide good thermal conductivity thereto but electrically isolated therefrom by mica laminae. An aluminum bracket firmly affixed to the sewing machine frame for good thermal conductivity has a large area planar surface thereof contiguous a similar large area planar surface of the heat sink member. A clamp member which extends through a slot in the bracket has a pair of upstanding arms with reentrant angles which touch the surface of the heat sink member opposite the large planar surface. The surface of the bracket opposite the large planar surface is formed with a cylindrical surface at an angle to coact with a cone pointed screw carried by the clamp member.

Abstract: An automatic back-tack feed control mechanism for the work feed regulating system of a sewing machine which feed regulating system includes a rock shaft and a feed block adapted to influence movement imparted to a feed dog for transporting work fabric transversely of the work surface of the machine according to a selected stitch length. A stitch length selector dial located on the machine includes a reverse feed button connected through a rock arm ultimately to the rock shaft so as to tilt the feed block for reverse feed motion of the feed dog for back tacking. At one preselected stitch length, back tacking is automatic for a predetermined number of stitches since the depression of the reverse feed button actuates a latch lever which locks the rock arm in a reverse feed position until a ratchet mechanism also set in motion by depression of the reverse feed button causes disengagement of the latch lever and rock arm whereby the feed dog is again placed in a forward feed mode.