Abstract: A wrenching portion provided in an adjuster and employed for assembling is formed at a gripping portion for rotation. The gripping portion is formed in a polygonal shape. In this configuration, the adjuster is decreased in size and weight and its operability of adjusting a driving depth is improved. An undercut portion is removed in a vertical direction and a non-slip rugged portion is provided in only a longitudinal direction so that it can be manufactured in a simple tow-part mold, thereby reducing the production cost.

Abstract: A wrenching portion provided in an adjuster and employed for assembling is formed at a gripping portion for rotation. The gripping portion is formed in a polygonal shape. In this configuration, the adjuster is decreased in size and weight and its operability of adjusting a driving depth is improved. An undercut portion is removed in a vertical direction and a non-slip rugged portion is provided in only a longitudinal direction so that it can be manufactured in a simple tow-part mold, thereby reducing the production cost.

Abstract: A pneumatic fastener driving tool includes a main valve operable to cause compressed air to be alternately introduced into and discharged from the upper piston chamber, a first passage leading the compressed air into the main valve chamber, a repeat valve disposed in the first passage for opening and closing the same, and a second passage extending between the lower piston chamber and a repeat valve chamber in which the repeat valve is reciprocably received. With this construction, the repeat valve is reciprocally movable in response to a change of pressure in the lower piston chamber to cause the main valve to reciprocate, thereby reciprocating the piston repeatedly. Since the reciprocating fastener driving movement of the piston is directly related to the reciprocating movement of the repeat valve, the fastener driving work can be achieved reliably without causing any operational failure such as a non-load striking.

Abstract: A pneumatic fastener driving tool including a start valve adapted to be open for start a fastener driving operation by pneumatically driving a driving rod forwardly, and a vent hole for connecting to start valve to atmospheric air to let compressed air escape to atmosphere when compressed air is accidentally supplied through the start valve after one cycle of fastener driving operation is completed due to bouncing of the piston, for example.