illustrated a sewing machine 1 the base plate 2 of which is received by a plate 3 fastened by posts 4 to a stand 5 above the base plate 2 there is displaceably supported a workpiece receiving device 7 via a linkage 6 for moving a workpiece 8 along the needle 9 of the sewing machine 1 according to a predetermined seam contour the workpiece receiving device 7 substantially consists of a pressure plate 10 acting upon workpiece 8 reference may be made to u s pat no 4 223 617 for this purpose the pressure plate 10 is formed with a slot 11 corresponding to the u shaped seam contour and allows the passage of the needle 9 the linkage 6 is journaled at a pivot 12 located at the stand 5 which also receives a reduction gear unit 14 secured thereto by screws 13 the gear unit 14 is provided with a vertical shaft 15 to which is mounted a control disc 16 by means of a nut 17 the sewing machine 1 is drivingly connected to an intermediate shaft 19 via a belt drive 18 and a clutch 18 39 the intermediate shaft 19 is rotatable in the stand 5 and is on one hand connected to the gear 14 via a belt drive 20 and on the other hand it is connected via a belt drive 21 to a motor 22 arranged at the stand 5.