The machine is equipped with a hook-drving shaft-offset mechanism which places the hook-rotating shaft off-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 result,this machine is immune to sewing trouble,such as stitch skipping and thread breakage.Annoyances likely to occur with the conventional machine.E specially when the needle throws to the right.