Abstract: Two workpiece portions (30, 32) that are to be stitched together along a stitching path (28) each have a stitching region (24, 26) which corresponds to the stitching path (28), but which is so shaped that the regions do not overlap when the workpieces (30, 32) are in a substantially flat condition. Thus some three-dimensional shaping is imparted to the portions during stitching. Each of the workpiece portions (30, 32) is clamped between two rollers (10, 12, 24) one of which is driven and the other freely rotatable, the driven rollers (10, 12) serving to distort the stitching regions into a desired overlapping position progressively in preparation for each successive stitching operation. The rollers are also bodily movable to advance the workpiece portions (30, 32) step-by-step through the operating locality (4) of the sewing machine. For sensing when the stitching regions are in the desired overlapping relationship suitable edge sensing means (40, 42, 44) is provided.

Abstract: A workpiece is supported by work support means (40; 40'; 40"; 44'; 142, 144) for movement in a first direction by co-operating workpiece clamping and feeding means (46; 142, 144), both said means being supported on a carriage (16) for movement in a second direction normal to the first to move a workpiece relative to a sewing machine head. Both of said means are arranged on both sides of an elongated aperture (42) extending in the second direction in alignment with a needle penetration point (N). Stepping motors (24; 60) are provided for moving the carriage (16) and operating the workpiece clamping and feeding means (46; 142, 144) under programmed control. A camera (70) is also provided aligned with the aperture 42, for detecting the peripheral outline of a workpiece fed therebeneath.