PERFECCIONAMIENTOS EN MECANISMOS DE PUNTADA FALSA PARA MA- QUINAS DE COSER

摘要

A gap stitch mechanism for a sewing machine containing a needle shaft which is oscillatingly driven by a crank assembly, wherein the crank assembly is provided with means for reducing the crank radius at predetermined intervals during the sewing operation, thereby determining the stroke of the needle shaft and making it impossible for the loop catcher to catch the needle thread.