MULTITHREAD CHAIN STITCH SEWING MACHINE

PROBLEM TO BE SOLVED: To provide a multithread chain stitch sewing machine that easily removes a thread control cam even if a looper thread is cut and curled and then removes the curled thread while the thread control cam does not interfere with the operation of texture even during sewing. SOLUTION: The multithread chain stitch sewing machine has a bobbin thread delivery device comprising a looper that reciprocates left and right at he lower portion of a throat plate in linking with the rotation of a spindle that is arranged at a sewing machine bed, a thread control cam where the amount of projection from a thread delivery stand changes in linking with the reciprocating movement of the looper, and a passage of reeling thread having a thread hole where the looper string is inserted. The multithread chain stitch sewing machine controls the amount of delivery of the looper string by sliding the looper string on the peripheral surface of the thread control cam. In the sewing machine, the strong control cam is fixed to the end section of a rotary shaft that is arranged next to the spindle, at least one end of a bearing for supporting the rotary shaft forms one portion of an inner wall in the sewing machine bed, and the spindle and the rotary shaft are connected by a timing belt.