Fastener driving tool

摘要

A fastener driving tool includes a cylinder and a drive piston reciprocally movable within the cylinder. A driver is connected to the drive piston and is operable to drive fasteners when the drive piston is moved in a driving direction. The drive piston defines a gas chamber in the cylinder for accommodating a gas. A drive mechanism is provided for moving the drive piston from a first position to a second position in a direction opposite to the driving direction for compressing the gas within the gas chamber. The drive mechanism is operable to permit movement of the drive piston in the driving direction by the pressure of the gas compressed within the gas chamber when the drive piston reaches the second position.