| 摘要 |
<p>The sewing machine includes respective setting members for adjusting the overstitch width and the stitch length, with the setting members being adjusted by an actuating mechanism responsive to control signals of a program control system, the control signals corresponding to the stitches to be made. The power for driving the actuating mechanism is derived from the continuously operating main shaft of the sewing machine, through a clutch or clutches whose moment to be transmitted is controllable, such as electromagnetic clutches. In one embodiment of the invention, a single electromagnetic clutch is provided for each setting member and includes a first clutch disk connected to the respective setting member to rotate therewith and a second clutch disk secured to a shaft continuously rotated by the main shaft of the machine. A spiral spring is provided to act to rotate the respective setting member in a direction opposite to the direction of rotation thereof by the associated clutch. In a second embodiment of the invention, two clutches are provided to rotate each setting member, each clutch including a first clutch disk. One clutch includes a second disk rotated by a shaft continuously driven by the main shaft, and the other clutch includes a second disk rotated directly by the main shaft, the two second clutch disks rotating in respective opposite angular directions. Thereby, the setting member is adjusted in accordance with the relative moments exerted by the two clutches.</p> |
