| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method and device for preventing raveling of a double chain stitch seam which can surely and strongly prevent the occurrence of raveling of a single needle double chain stitch seam irrespective of the magnitude of tension applied to a needle thread and a looper thread. <P>SOLUTION: The method prevents raveling of a double chain stitch seam formed by catching a needle thread loop 20a, which is formed below a needle plate by a needle, through the advance of a looper operable to be advanced and retreated in a direction substantially orthogonal to the vertical movement path of the needle, and by interlooping the needle thread loop with a looper thread 10. The method includes: after a normal sewing is finished with the looper set in an advanced state, maintaining a state in which the needle thread loop caught by the looper is held at a position which is closer to the advanced end of the looper than a needle lowering position until the needle lowers through the needle thread loop caught by the looper; and intralooping the needle thread loop with a needle thread held by the needle by releasing the position holding of the needle thread loop and performing a sewing operation for at least one stitch. <P>COPYRIGHT: (C)2013,JPO&INPIT |
