Patent ID: 8479963
Filing Date: 2013-07-09
Classification: B25C

Abstract:
1. A pneumatic driving machine comprising: a housing; a cylinder provided in said housing; a piston reciprocating between a first position and a second position within said cylinder and dividing the interior of said cylinder into an above-the-piston chamber and a below-the-piston chamber; a driver blade fixed to said piston and hitting and driving a fastener into a workpiece; an accumulator accumulating compressed air for moving said piston from said first position to said second position; a main valve sending said compressed air accumulated in said accumulator to said above-the-piston chamber to move said piston from said first position to said second position upon operation of a trigger; a return air chamber communicating with said above-the-piston chamber while said piston is positioned at said second position, communicating with said below-the-piston chamber while said piston is positioned at said second position, and accumulating compressed air supplied from said above-the-piston chamber when said piston moves from said first position to said second position; and a pressure control means controlling the pressure in said return air chamber.