Abstract: In order to permit a reliable alignment, in the direction transverse to the direction of rotation, of the edge 5 of the opening of a tubular workpiece 4 of medium-heavy to heavy sewing material which is drawn with considerable pre-tension over a tensioning device 3, each of the tensioning rollers 6, 7, 8 belonging to the tensioning device 3 has at least three alignment members 15 distributed uniformly over its circumference. Each alignment member 15 has an engagement side with a gripping surface. After optically scanning the edge 5 of the opening of the workpiece 4, one or more of the alignment members are displaced by a pulsating action of a pressure fluid, radially and axially, in the tensioning roller 6, 7, 8. In this way, the gripping surfaces of the alignment members 15 grip the inner side of the tubular workpiece 4 and displace it transversely to its direction of rotation.

Abstract: A cutting device for cutting the thread chain, or the like, between successive sewn parts moving along a path through a sewing machine. The sewing machine includes a needle. A holder downstream of the needle includes a horizontal cutout. A hook for lifting the thread chain between adjacent sewn parts on the path is movable up through the cutout for raising the thread chain. A scissors moves across the sewn part path and cuts the upraised thread chain. The holder holds the upstream sewn part from shifting while permitting the downstream sewn part to shift slightly upstream as the hook rises and prior to the cutting, whereby a single cut cuts the thread chain adjacent both sewn parts. A sensor senses the trailing edge of a sewn part and activates a stitch counter to cause the needle to apply a predetermined number of stitches before halting sewing so that the cutting can thereafter take place.