Abstract: A sewing machine employing a stepper driven-stitch patterning mechanism including a stepper rotated cam with a spiral cam groove tracked by a follower formed with different cross sectional shape than the cam groove in order to provide only point contact with each side of the cam groove when spring biased therein. A spring arrangement biases the cam and follower together in a direction perpendicular to the axis of cam rotation, thus minimizing lost motion between cam and follower.

Abstract: The feeding length in a sewing machine depends on the difference between the positions of the feeder when it rises above the stitch plate and when it sinks again. In previous devices the feeder is controlled by the angular position of a guide which is kept constant during the feeding phase. According to the invention the angular position of the guide can be re-adjusted during the feeding movement. At the moment when the feeder rises above the stitch plate the angular position determines a portion of the feeding length, while the angular position at the moment when the feeder sinks again determines the rest of the feeding length.

Abstract: In a sewing machine, particularly an industrial sewing machine, with a needle which can be driven up and down by means of a needle bar, a feed dog for the forward transfer of the workpiece in co-ordination with the needle movement, an actual feed rate sensing device which supplies a corresponding electric signal and at least one sensor for detecting a workpiece edge, for the purpose of increasing the accuracy of the positioning of the corner stitch of a seam portion with acceptable constructional expenditure, a device is provided for displacing the longitudinal axis of the needle parallel to the sewing direction as a function of the actual feed rate sensing device on the one hand and the detection of a workpiece edge by the sensor on the other.

Abstract: An electronic control for a sewing machine, which electronically stores needle amplitude amounts and feed amounts as pattern signals, including a control motor having an output shaft with a center, an output arm affixed to the output shaft of the control motor and a guide pin connected with the output arm and a guide cam disposed at a predetermined distance to the control motor and having first and second grooves being arc-shaped and having different radii from the center of the output shaft of the control motor so as to provide both normal and reduced amounts of feed.

Abstract: An electronic control sewing machine for producing stitching patterns by storing as programs in a memory the pattern signals for the amount of needle bar amplitude and the amount of fabric feed, includes control motors having output shafts which have rotational outputs and are driven in response to the pattern signals per rotation of the sewing machine. The machine further includes pawl members having pawls, and cam bodies positioned on the output shafts of the control motors and each including a plurality of cam faces. The pawl members and the pawls are switched to different ones of the plurality of cam faces by the control motors in accordance with the programs stored in the memory of the sewing machine.