| 摘要 |
A sewing machine possessing multiple needles and a single looper for forming a double chain stitch without an upper covering thread capable of drawing out a thread chain reliably and smoothly. By using an auxiliary blade disposed parallel to a looper, the thread chain consecutive to the looper is supported, thereby preventing the thread chain from being pushed down beneath a throat plate by descending needles. On the throat plate, a stitch formation tongue composed of a movable slender plate is provided, and this tongue is withdrawn when making the thread chain. The sewing machine is provided with tension regulators for sewing and for forming a thread chain respectively. In the tension regulators for forming the thread chain, the tension of the right needle thread is set lower than the tension of the looper thread. By use of a rear feed dog, the thread chain is drawn out through a guide groove at the left rear end of a needle hole toward the middle of the rear feed dog.
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