| 摘要 |
PROBLEM TO BE SOLVED: To provide a multi-thread chain stitch seam structure which can reliably and strongly prevent the occurrence of raveling in a multi-thread chain stitch seam irrespective of the magnitude of tension applied to a needle thread and a looper thread.SOLUTION: A multi-thread chain stitch seam structure is formed on a sewing fabric by: catching a needle thread loop which is formed below a needle plate by a needle vertically moving while holding a needle thread, by the advance of a looper capable of advancing and retreating in a direction substantially orthogonal to the vertical movement path of the needle; and interlooping the needle thread loop with a looper thread held by the looper. A needle thread loop located at a terminal end in a sewing advance direction among needle thread loops on the back side of the sewing fabric in a seam formed on the sewing fabric is self-looped with the needle thread subsequently passing through the sewing fabric. |
