Patent ID: 7290691

Claim:
A pneumatic nail gun comprising: a gun body, which has a main air housing collecting a compressed high pressure air with a constant pressure, and a trigger at one end of the main air housing driving the high pressure air to shoot a nail; a cylinder fixed in the main air housing; a hitting piston slidably movable in the cylinder; a dish-shaped piston disposed at a top end portion of the cylinder, which is driven to move upward and guide the high pressure air into the cylinder for driving the hitting piston to rapidly move downward when the trigger is pressed, and is driven to move downward by the high pressure air in the main air house for closing the fluid communication into the cylinder when the trigger is released; an upper slidable sleeve valve disposed at a top portion of an outer peripheral surface of the cylinder, which is driven to move upward by the high pressure air in the main air housing when the trigger is released; a lower slidable sleeve valve disposed at a lower portion of an outer peripheral surface of the cylinder, which is driven to move downward for guiding the high pressure air into the cylinder for upward deposition of the hitting piston when the upper slidable sleeve valve moves upward, and is driven upward when the hitting piston moves to its upper dead center, the upper slidable sleeve valve being driven to downward reposite and closing the fluid communication to the lower slidable sleeve valve.