PURPOSE: To accurately stop a tool at its resting position, by engaging input and output shafts through irreversible one-way clutch which can rotate these shafts at a constant phase upon coupling even after engaging and disengaging actions thereof are repeated.

CONSTITUTION: When a starting switch 51 is turned on, a switch 54 of a solenoid 41 is turned on so that an output shaft 32 initiates to rotate and a clutch of an electromagnetic clutch brake 27 engages at each displacement thereof to intermittently operate a deliver roller 28. AND signals generated at a first main shaft synchronous switch 48 and the starting switch 51 are transmitted to a first cycle counter 52, as well as an input side of the solenoid switch 54, to start the first cycle counter 52 which counts the member of cycles of a reciprocating toll 18. When the counter 52 counts a preset cycles, a count-up signal is generated to turn off the switch 54 of the solenoid 41. A stepped part 39 of a stop collar 36 engages a claw 40 to stop the output shaft. Consequently, input and output shafts are engaged in a constant phase so that the stopping position is consistent with a waiting rest position of the tool.