Patent ID: 7458429

Claim:
A pneumatic hand tool consisting essentially of: a hollow body having a space in a front portion thereof, a control knob mounting portion and a threaded bolt extension portion both defined in a closed rear end of the body; a cylinder assembly composed of a cylinder, a rotor, a front cover, a first bearing, a second bearing, wherein the cylinder is provided with a first leakproof portion, a second leakproof portion, a rotor receiving recess to receive therein the rotor and a rotor receiving chamber, the rotor has a front shaft extending through the front cover to have the first bearing mounted therearound and provided with a first coupling portion formed on the front shaft, a rear shaft oppositely extending relative to the front shaft and through the rear side of the cylinder to have the second bearing mounted therearound, the font cover is securely connected to the cylinder so as to allow the cylinder assembly to be received in the space of the body; a sealing pad mounted between the body and a front cap to allow the body to engage with the front cap in a airtight manner; a striking assembly having a central axle extending from a side thereof and a coupling portion formed oppositely relative to the central axle to correspond to and engage with the first coupling portion of the rotor; a front cap having a through hole defined in a front portion thereof to allow extension of the central axle of the striking assembly and apertures defined around a side face of the front cap such that when the front cap is connected to the body, threaded bolts are able to extend through threaded bolt extension portion of the body and the apertures of the front cap to secure engagement between the body and the front cap; a control knob, which is composed of an air plug and an adjustment knob, wherein the air plug is extended through the control knob mounting portion of the closed rear end of the body; the adjustment knob is coupled with the control knob mounting portion of the closed rear end, and the end of the air plug is also coupled with the adjustment knob tightly.