Circular stitcher for sewing machine and sewing machine

摘要

A circular stitcher for a sewing machine having a bed and a needle plate, and a feed dog includes a base attachable to an upper surface of the bed or the needle plate; a pin support seized movably in a predetermined direction by the base and having an engagement subject; a pin having an engagement engagable with the engagement subject of the pin support and a needle that pierces a workpiece cloth from an underside of the workpiece cloth at a laterally spaced position from a needle drop point, the needle assuming a center of rotational cloth feed executed by the feed dog during circular stitching; and a lock mechanism provided in the pin support and releasably locking the engagement and the engagement subject together.