Gripper-drive mechanism for a sewing machine

摘要

A gripper-drive mechanism for a sewing machine has the following: two grippers (2, 3); gripper-drive shafts (14, 17) for driving the grippers (2, 3); a main shaft (5) which runs in a plane relative to the gripper-drive shaft (14, 17); and torque-transmission units for transmitting the rotation of the main shaft (5) to the gripper-drive shafts (14, 17). The transmission units have the following: two oblique-groove cams (6, 7) which are arranged fixedly on the main shaft (5) and which have grooves which each extend over a full circumference and obliquely relative to the main shaft (5); U-shaped cam followers (21, 22), each with two rollers (25), each of which is supported by the gripper-drive shaft (14, 17) and rotates about its own axis in the groove of the oblique-groove cams (6, 7); and connecting pins (23) for the pivotable attachment of the U-shaped cam followers (21, 22) to the gripper-drive shafts (14, 17), so that the U-shaped cam followers are not rotatable in a direction parallel to a line connecting the two rollers (25) to one another, but are rotatable in a direction perpendicular to the line connecting the two rollers (25) to one another. <IMAGE>