IMPROVEMENTS IN OR RELATING TO LENGTHS OF SLIDING CLASP FASTENER CHAIN

摘要

A coupling coil is lockstitched to the longitudinal edge of a support tape with a transparent synthetic-resin mono-filamentary thread overlying the individual coil turns. The coil and the tape are dyed and the thread is left transparent. In this manner the color of the coil is visible through the attachment thread and there is no color contrast apparent between this thread and the rest of the stringer. Heat treatment of the dyed and assembled stringer flattens the monofilament over the coil to attach the coil securely to the tape and to make the thread blend in as much as possible. A single needle Type 401 or a double-needle Type 402 double locked stitch may be used.