Handheld pneumatic power tool apparatus

A handheld pneumatic power tool apparatus for use with a supply of pressurized air, the apparatus comprising:

• a handpiece including a cylinder having first and second ends, an anvil positioned at the first end of the cylinder, a piston received in the cylinder for bi-directional movement between the ends, and a pneumatic oscillating means for oscillating the piston back and forth within the cylinder into and out of engagement with the anvil,
• the pneumatic oscillating means including an air inlet for introducing pressurized air to the cylinder to bias the piston toward one of the ends of the cylinder, an exhaust means for exhausting air from the cylinder after the air has moved the piston toward the one end, and a piston biasing means for biasing the piston away from the one end such that the piston is moved away from the one end as air is exhausted from the cylinder;
• and
• a pressure regulating means connected between the supply of pressurized air and the handpiece for regulating the pressure of air supplied to the handpiece, the pressure regulating means including a valve for controlling air flow to the handpiece, a pressure sensing element for sensing the pressure of the air supplied to the handpiece and for automatically controlling the valve to regulate the pressure of the supplied air, an element biasing means for biasing the pressure sensing element against the pressure of the supplied air, and a foot pedal operatively connected to the element biasing means for adjusting the force exerted by the element biasing means on the pressure sensing element in order to adjust the regulated pressure of the supplied air.