Feed drive for the work holder of a zig-zag sewing machine

A feed drive for the work holder of a zig-zag stitch group sewing machine comprises a rotatable cam plate and a work holder which is engaged with the plate and moved thereby within a rectilinear guide arranged adjacent the head portion of the sewing machine. The work holder is located adjacent the needle and it includes a driver plate which extends below the sewing machine arm portion and grips the workpiece from above. The cam plate is arranged in a standard of the machine and the work holder is driven by engagement of a sensing element in a groove of the cam plate which is connected to the work holder through a lever drive acting on a rotatable shaft arranged below the arm of the machine and connected with a crank and a link with a slide carrying the work holder which is disposed in a guide. The construction includes a seating for the workpiece which is movable parallel to the guide and is coupled with the driving plate. This comprises two endless belts which are disposed on freely rotatable guide rollers and which have a spacing corresponding to the maximum swinging amplitude of the needle.