Patent ID: 7156012
Filing Date: 2007-01-02
Classification: B25C

Abstract:
1. A fastener driving tool comprising: a frame defining therein an accumulator that accumulates a compressed air; a cylinder disposed within the frame; a piston reciprocally slidably disposed within the cylinder, a piston upper chamber being defined by an inner peripheral surface of the cylinder and an upper surface of the piston; a main valve which alternately opens and blocks a fluid communication between the piston upper chamber and the accumulator; a main valve chamber section defining therein a main valve chamber in which the main valve is movably disposed, the main valve chamber providing a maximum internal volume; a trigger valve which alternately opens and blocks a fluid communication from the accumulator to the main valve chamber, and a fluid communication from the main valve chamber to an atmosphere; and a main valve control channel section defining therein a main valve control channel that provides a fluid connection between the main valve chamber and the trigger valve, the main valve control channel having a cross-sectional area, a ratio obtained from dividing the maximum internal volume of the main valve chamber measured in m