Compensating needle bar connecting linkage for a sewing machine

摘要

A zig-zag sewing machine is provided with a compensating link and slide which engage on curved surfaces extending in a circular arc that has its center in line with the link. The compensating link and slide are situated between a crank and needle bar and move relative to each other during zig-zag operations to modify the operating effect of the crank and cause a needle to be similarly positioned relative to a vertical axis hook for loop taking in alternate zig-zag positions of the needle bar.