Patent ID: 6119613
Filing Date: 2000-09-19
Classification: D05B

Abstract:
A method for preventing a seam from raveling in a double chain stitch sewing machine, having at least one needle moving vertically through which a needle thread is passed, and a looper through which a looper thread is passed, for forming a double chain stitch by collaboration of the looper thread and the needle thread, while the looper moves forward and backward between a forward position and a backward position across the needle, said method comprising the steps of:hooking and engaging a looper thread consecutive to the looper from a cloth by an engaging means when the looper is in an advanced state relative to the forward position near the sewing end point;cutting off the looper thread hooked and engaged on the engaging means at its engaging portion;cutting off a needle thread loop consecutive to the needle from the cloth through the looper at a position between the cloth and the looper in a state when the looper is advanced again from the backward position to the forward position as the sewing machine is driven; andpulling out an end of a cut looper thread left over at the looper side from a final needle thread loop formed in the cloth.