Composite sewing machine with single needle for lock and overlock stitches

Abstract

A composite sewing machine has a lock stitch mechanism and an over-lock stitch mechanism. A switching mechanism is connected to the stitching mechanisms for switching the operation of the sewing machine between a lock stitch operation and an over-lock stitch operation. The machine has a single needle carrying element, a needle position converter for changing the position of the needle carrying element laterally of the stitching direction and including a needle bar connecting stud engaging the needle carrying element and a fulcrum shaft on which the stud is rotatably mounted for pivotal movement to change the vertical orientation of the needle carrying element between a lock stitch position and an over-lock stitch position which are adjacent to each other and juxtaposed laterally on the sewing machine. The over-lock stitch mechanism has an upper looper and a lower looper at the over-lock stitch position, a looper driving mechanism connected to the loopers and including a clutch connecting the driving mechanism to the over-lock stitch mechanism, whereby one needle is adapted to be used for both lock stitching and over-lock stitching.

Dependencies are inferred from the claim text.