The machine is equipped with a hook-driving shaft-offset mechanism which places the hook-rotating shaft off-center from the center of Zigzag stroke of the needle.This mechanism allows the blade point of the hook to catch the needle thread every time regardless of the needle throwing direction. As a rusult,the machine is immune to sewing troubles,such as titch skiping and thread breakage,regarding stretched material,flosting presser foot will be lifted accordingly so that sewing smoothly and beautiful stitching.