Patent ID: 7373992

Claim:
A pressure regulating valve assembly for a pneumatic hand tool having an air inlet channel, the pressure regulating valve assembly comprising: an inlet fitting having an inlet aperture adapted to receive an air line providing a source of pressurized air, the inlet fitting including a tubular portion having an inside diameter; a valve member slideably disposed in the inlet fitting, the valve member including a square centering portion having a diagonal dimension slightly smaller that the inside diameter of the inlet fitting tubular portion; a collar retained in the inlet fitting, the collar having a piston aperture; a piston having a tubular proximal end that slidably engages the piston aperture in the collar, and an annular head portion, the piston defining an axial channel therethrough, the piston being movable between an open position and a closed position; a biasing member that biases the piston toward the open position; wherein, when the piston is in the open position a fluid flow path through the inlet aperture and through the axial channel in the piston is open, and when the piston is in the closed position the piston abuts the valve member such that the fluid flow path is closed.