Chain stitch sewing machine with looper drive and lock arrangement

Abstract

In a chain stitch sewing machine which performs a required chain stitch sewing with respect to a cloth to be processed, by cooperation of a needle reciprocable up and down and a looper arranged under a needle plate, the chain stitch sewing machine comprises: (1) a large diameter drive gear rotatably provided in a base, (2) a looper support supported by the base so that it can slide in a lateral direction, (3) two or more loopers arranged on the looper support at intervals of a predetermined pitch along the lateral direction and freely rotatable on their own axes, (4) small diameter driven gears respectively provided in the two or more loopers and each engageable with the drive gear, and (5) a lock mechanism for non-rotatably locking the two or more loopers at a required timing. When all loopers are non-rotatably locked by the lock mechanism, the driven gears provided in the loopers will form a rack, and if the drive gear (serving as a pinion) is rotated and engaged by the driven gears forming the rack, the driven gears as a whole will be slid in a lateral direction. With this rack and pinion mechanism, a desired looper is selected. In addition, if the locking of the selected looper, positioned in a facing relationship with the drive gear by the looper selecting operation, is released and the drive gear is rotated, the rotation of the selected looper will be controlled.

Dependencies are inferred from the claim text.