| 摘要 |
PURPOSE:To remove a screw left in a chuck unit due to protruding action of a driver bit, by performing a lift of the first stage with air and the second stage with resetting of a spring in a two-stage cylinder mechanism built in a driver main unit. CONSTITUTION:If air is supplied from the second supply discharge port 20 and discharged from the first supply discharge port 19, a stepped cylinder 18 is lifted simultaneously also a chuck unit 22 is integrally lifted. On the contrary, because a piston 23 is reset lifting at a resetting speed of the second spring 29, a driver bit 30, during the time of its lift resetting, is once protruded from the unit 22, and improper screw tightening is caused to remove a screw left in the unit 22 and prevent duplication of the screw in the unit 22. |
