Abstract: A pneumatically operated fastener driving tool capable of avoiding accidental release of a head bumper from a housing. The head bumper is made from an elastic material and is compressedly fitted to the housing. The head bumper has a contacting portion deflectable upon application of compressed air. A discharge port is formed at one of the housing and the head bumper to discharge the applied compressed fluid to an atmosphere.

Abstract: A fastener driving tool includes a frame defining therein an accumulator that accumulates compressed air, a cylinder, a piston movable between a top dead center and a bottom dead center, a main valve section having a main valve movable between a top dead center and a bottom dead center to alternately open and block fluid communication between a piston upper chamber and the accumulator, a trigger valve section having a plunger movable between a top dead center and a bottom dead center so as to alternately open and block fluid communication from the accumulator to a main valve chamber, and fluid communication from the main valve chamber to atmosphere, and a trigger adapted to press the plunger when operated by a user. The piston moves from the top dead center to the bottom dead center within 11.3 msec when the plunger is pressed.

Abstract: An outer peripheral surface of a cam has an apex disposed of distance from a rotational axis, a first region adjacent the apex opposite to the direction of rotation that increases in distance from the rotational axis during rotation, and a second region adjacent the apex in the rotational direction that decreases in distance from the rotational axis of the cam with the rotation thereof. The apex is disposed where the phase ? thereof advances by 15 degrees and 55 degrees or less in the rotational direction from a position symmetrical to the rotational axis. The rate of change between the second region and the rotational axis is greater than the rate of change between the first region and the rotational axis. A retreat amount X when a saw blade reaches an uppermost point c from a foremost point is set to 0.8 mm.

Abstract: A pneumatically operated fastener driving tool capable of avoiding accidental release of a head bumper from a housing. The head bumper is made from an elastic material and is compressedly fitted to the housing. The head bumper has a contacting portion deflectable upon application of compressed air. A discharge port is formed at one of the housing and the head bumper to discharge the applied compressed fluid to an atmosphere.

Abstract: A fastener driving tool includes a frame defining therein an accumulator that accumulates compressed air, a cylinder, a piston movable between a top dead center and a bottom dead center, a main valve section having a main valve movable between a top dead center and a bottom dead center to alternately open and block fluid communication between a piston upper chamber and the accumulator, a trigger valve section having a plunger movable between a top dead center and a bottom dead center so as to alternately open and block fluid communication from the accumulator to a main valve chamber, and fluid communication from the main valve chamber to atmosphere, and a trigger adapted to press the plunger when operated by a user. The piston moves from the top dead center to the bottom dead center within 11.3 msec when the plunger is pressed.

Abstract: An outer peripheral surface of a cam has an apex having a greatest distance from a rotational axis, a first region located on the side of the apex opposite to the direction of rotation and having an increasing distance from the rotational axis with the rotation thereof, and a second region located on the side of the apex in the rotational direction and having a decreasing distance from the rotational axis of the cam with the rotation thereof. The apex is disposed in a position where the phase 0 thereof advances by 15 degrees or more and 55 degrees or less in the rotational direction from a position symmetrical to a center of the pin with respect to the rotational axis. The rate of change in the distance between the second region and the rotational axis is set to be greater than the rate of change in the distance between the first region and the rotational axis. A retreat amount X when a saw blade reaches an uppermost point c from a foremost point is set to be 0.8 mm or more at a lower end of the saw blade.

Abstract: A pneumatically operated fastener driving tool capable of reducing a time period from operation timing of a trigger to downward movement of a driver blade for fastener driving, and reducing a time period from the release timing of the trigger to a timing at which respective components are returned to their initial positions for a subsequent nail driving. As components a main valve and a trigger valve is provided. The main valve is movable within a main valve chamber connected to a main valve control channel. The trigger valve selectively provides fluid communication between the accumulator and a main valve chamber through the main valve control channel and between the main valve chamber and the atmosphere through the main valve control channel. A ratio of cross-sectional area of the main valve control channel to an internal volume of the main valve chamber is defined to a specified ratio.

Abstract: A pneumatically operated fastener driving tool capable of reducing a time period from operation timing of a trigger to downward movement of a driver blade for fastener driving, and reducing a time period from the release timing of the trigger to a timing at which respective components are returned to their initial positions for a subsequent nail driving. As components a main valve and a trigger valve is provided. The main valve is movable within a main valve chamber connected to a main valve control channel. The trigger valve selectively provides fluid communication between the accumulator and a main valve chamber through the main valve control channel and between the main valve chamber and the atmosphere through the main valve control channel. A ratio of cross-sectional area of the main valve control channel to an internal volume of the main valve chamber is defined to a specified ratio.

Abstract: The object of the present invention relates to reduction of noise during no-load running of a gear device and is to provide a gear shock absorbing mechanism, by which it is possible to damp collision force of tooth against tooth by simplified structure and to reduce gear noise. A driven gear is connected to a driven shaft via a radial gap, and a key connects the driven gear with the driven shaft in rotating direction via a peripheral gap, and an elastic member is compressed in axial direction and is placed between a stop washer connected with the driven shaft and the driven gear.