Abstract: A presser lifting arrangement for an industrial sewing machine having a knee shift device which manually elevates a presser foot to a height above the work fabric to permit free movement of the work fabric therebeneath. Further motion of the knee shift device actuates a snap action switch which operates to connect a solenoid to a source of power to elevate the presser foot to its maximum height. In a second embodiment, the knee shift device includes internal switch contacts which energize a first solenoid to raise the presser foot a distance sufficient to permit free movement therebeneath, and continued actuation of the knee shift pad actuates a snap action switch which energizes a second solenoid to raise the presser foot to its maximum height.

Abstract: A light sensing device for a sewing machine with a sensing circuit which automatically compensates for the work fabric being utilized so as to be able to detect a ply change event in any fabric without requiring an operator adjustment for the type of fabric being stitched upon. Being able to detect a ply change event without the necessity for adjustment also permits automatic operation of certain sewing machine components, further facilitating operation of the sewing machine.

Abstract: A sewing machine is described having a presser foot lifting arrangement actuated by a presser lifting rock shaft in the sewing machine arm and both a power operated presser lifting device such as a pneumatic cylinder, electric solenoid, or other actuator as well as an operator controlled presser lifter actuator such as a knee shift or the like wherein there is provided linkage means connecting the presser lifting rock shaft in the sewing machine arm with both the operator influenced and power driven actuator. The linkage means is formed with a pair of parallel lost motion slots each embracing a crank pin associated with a respective one of the actuators so that both actuators are connected for independent operation without influence on each other.