Method and apparatus for preventing seam from raveling in double chain stitch sewing machine

Abstract

The method and apparatus for preventing seam from raveling in a double chain stitch sewing machine of the invention are applied mainly in sewing of cloth by a double chain stitch sewing machine with multiple needles, and when nearing the end of sewing for forming a double chain stitch S by collaboration of a plurality of needles 5, 6 and a looper 3, a looper thread 10 consecutive from the cloth W to the looper 3 is engaged with a hook 15, and in this state, consequently, needle threads 8, 9 consecutive to the needles 5, 6 from the cloth W through the looper 3, and the looper thread 10 consecutive to the looper 3 from the cloth W are cut off, and the looper thread 10 engaged with the hook 15 is also cut off simultaneously or before or after this cutting, and therefore the looper thread 10 consecutive to the sewing end of the cloth W is set in discontinuous state, and raveling of sewing thread is securely prevented, while the length of the thread end consecutive to the sewing end is shortened, so that a sewn product of an attractive appearance may be obtained.

Dependencies are inferred from the claim text.