Patent ID: 6725790
Filing Date: 2004-04-27
Classification: D05B

Abstract:
A cloth cutting knife driving device in a sewing machine, the device comprising:a drive shaft, able to swing rotatably, by interlocking with a main shaft; a rocking arm rotatably supported on the drive shaft at the distal end for rocking motion; and a cloth cutting knife supported at the distal end of the rocking arm, to be rigidly held in a cloth cutting position and an inactive position, and able to move up and down through the rocking motion of the rocking arm; wherein the device has a coupled state and a released state between the drive shaft and the rocking arm, both states being brought about by an engaging part of the drive shaft and a movable member, that is movable with respect to the rocking arm in a direction perpendicular to an axial direction of the drive shaft; and wherein the coupled state is achieved by engaging the movable member with the engaging part, with the movement of the movable member in the axial direction toward one side, and the released state by releasing the movable member from the engaging part with the movement of the movable member toward the opposite side.