Patent ID: 7891307

Claim:
A method for forming single-thread locked handstitches, comprising the steps of (a) capturing a thread which is drawn out from a thread exit of a shuttle hook positioned under a throat plate, winding the thread and performing a half-turn reverse rotation, and which abuts circumferentially on an open eye needle and is tightened by a thread capturing open eye when the open eye needle which equips the thread capturing open eye laterally and performs a linear reciprocating motion vertically comes down from an upper dead center, pierces a fabric workpiece which is placed on the throat plate, and goes up from a lower dead center during a first stroke, (b) feeding one stitch length of said fabric workpiece, and tightening a thread by a rise of said open eye needle which captures said thread, and by performing a further reverse rotation of said shuttle hook while the open eye needle slips out from the fabric workpiece, goes up, and passes through the upper dead center during the first stroke, (c) scooping the thread which is captured by said thread capturing open eye by a loop-taker point of said shuttle hook which performs the half-turn normal rotation, and releasing the captured thread by the rotation of said shuttle hook from said thread capturing open eye when said open eye needle comes down from the upper dead center, pierces said fabric workpiece, and goes up from the lower dead center during a second stroke, (d) guiding in the thread which is scooped by the loop-taker point of said shuttle hook and released by the further rotation of said shuttle hook into said shuttle hook, interlacing the thread to the thread which is wound in said shuttle hook, and tightening the thread which guides out from said shuttle hook, (e) feeding one inter-stitch pitch of said fabric workpiece while the open eye needle slips out from the fabric workpiece, goes up, and passes through the upper dead center during the second stroke, and (f) forming a handstitch on a front surface and a locked stitch on a back surface of said fabric workpiece by repeating the steps from said (a) to said (e).