GB1263205A - Improvements in or relating to double-chain-stitch sewing machines - Google Patents

Abstract

1,263,205. Sewing machines. G. M. PFAFF A.G. 24 April, 1970 [26 April, 1969], No. 19746/70. Heading D1G. A double-chain-stitch sewing machine includes a thread-carrying oscillating looper movable in a straight or elliptical path and having a support 3 with a thread guide bore 7 therein and a beak 4, preferably with a thread guide bore 5 and thread guide groove 6; extending therefrom, a thread catcher 16 forming part of a cutting device and operable from a rest position to a cutting position, when the catcher 16 engages a cutting edge, for drawing out of the looper thread, a spring urged thread clamping plate 17 pivoted at 10 to the support 3 about an axis which is parallel to the axis of the bore 7 and having a thread guide bore 11 registering with the bore 7 during normal operation of the machine but being displaced relative thereto to clamp the thread 20 between the plate 17 and the support 3 when the plate is deflected, as by the action of the camming edge 15 on the abutment 14, as the thread catcher is displaced from its rest to its cutting position. The end positions of the plate 17 are determined by a slot 12 in the plate through which passes a screw 19 for adjusting the tension of the spring 18. In operation after the thread 20 has been cut a length of thread is retained on the looper of a sufficient length to sew a number of starting stitches after which the tension in the thread 20, between the plate 17 and a thread take up before the bore 11, pivots the plate 17 to its position with the bores 7 and 11 aligned.