| 摘要 |
<p>A pneumatic system applicable for pneumatically powered tools or the like comprises a pair of reciprocating slidable pistons arranged in tandem-like fashion within respective forward and rear chambers of a main cylinder. A two position valve means is selectively operable to divert the incoming pneumatic fluid to either of the two chambers while simultaneously diverting the exhaust therefrom to an auxiliary output. Pressurization of the forward chamber in the forward stroke is accomplished by providing a passageway through the rear piston for channeling the pressurized fluid into the forward chamber to employ the composite thrust of both pistons during the work cycle. On the back stroke, the rear piston is returned to its initial position by engagement with the rearwardly moving front piston upon selective pressurization of the front chamber. An auxiliary cylinder may be coupled to the auxiliary output for selective pressurization thereof whereby the auxiliary cylinder may further comprise a feed mechanism selectively sequenced by the pressure developed in the auxiliary output. The system may also include a pressure reducer for further selectively pressurizing the auxiliary output to provide a selectively cycled low level pressure in the auxiliary cylinder.</p> |
