Abstract: Stitch quality monitoring system for use in combination with a sewing machine having one or more stitch threads and comprising sensor means for at least one of said one or more stitch threads for detecting thread motion during each sewing stitch cycle. Encoder means is operatively associated with the sewing machine for creating a predetermined constant number of sensor means sampling signals for each stitch cycle of the sewing machine, and circuit means is electrically connected to the sensor means and encoder means for detecting stitch defects during the formation of potentially defective stitches.

Abstract: A sewn seam monitoring system for evaluating selected characteristics of seam formed from a plurality of fabric plies is disclosed comprising a vertically displaceable wheel for compressing and monitoring the thickness of a seam being sewn as the seam passes therebeneath and a transducer operatively connected to the wheel to measure vertical movement and generate a signal corresponding to the vertical displacement of the wheel. Computer means is electrically connected to the transducer for analyzing the seam being sewn to detect any defects therein sensed by the wheel when in compressing contact with the seam passing therebeneath.