| 摘要 |
PROBLEM TO BE SOLVED: To maintain continuously constant tightness of a tread (balance between needle and bobbin threads forming a seam) irrespective of changes in the sewing speed of a sewing machine in sewing operation. SOLUTION: This device for constant tightness of a sewing machine thread comprises an operating pedal 2 for control of the rotating speed of a sewing machine, an operating member 9 movably supported on a sewing machine arm 1, a regulating member 6A for varying a needle thread lift according to the movement of the operating member, and a coupling member 10 coupling the operating pedal 2 and the operating member 9.
|
