| 摘要 |
Disclosed is a three-stage valve switch structure, having a specifically designed main switch and an auxiliary switch, and is operated in cooperation with a forward rotation air passageway, and a reverse rotation air passageway, so that air of an air pump enters into a pneumatic device from said air passageway in driving an oil piston into forward rotation, pulling action, and reverse rotation; and said auxiliary switch is utilized in a condition that, in case that retrieving from a rivet nut done by a pneumatic machine tool is not complete, then said auxiliary switch can be pressed down for driving said pneumatic device into rotating its blades in a reverse manner, hereby reversely rotating said oil piston to make said retrieval from rivet nut more complete. The application of the present invention is not restricted to rivet-nut-riveter, it can also be utilized in pneumatic machine tools requiring forward rotation, pulling action, and reverse rotation functions. |
