| 摘要 |
PURPOSE: A buttonhole stitch sewing machine is provided to expand a swing angle of a swing stand and a looper by rotating a swing motor over 360°, and to return the swing motor to an original location conveniently. CONSTITUTION: A buttonhole stitch sewing machine includes a looper and a swing device(60) in a bed part with a needle stand inside an arm part of a sewing machine frame. The swing device includes a swing motor(61), a driving pulley(62) connected to the swing motor, a transfer shaft(64) transferring torque to the needle stand, a second driven pulley(65) connected to the transfer shaft; and a timing belt(66) offering torque to each driven pulley from the driving pulley. A zero-point detecting unit(68,69) is installed to detect an origin location of the swing motor. |
