REACTION ABSORBING DEVICE FOR DRIVING MACHINE

PURPOSE:To absorb reaction in the case of rapidly stopping a piston of a driving machine. CONSTITUTION:A return bumper 15 for receiving a piston stopped, when the piston 4 for supporting a driving driver 3 is retracted in a cylinder 2, is longitudinally movably provided in a cylinder rear part. The return bumper is always energized to an advancing position by an elastic member 18. A reaction absorbing valve 56 is provided behind the cylinder 2, and when the return bumper 15 is retracted by compressed air in a piston rear part chamber 2a of the cylinder 2, the valve 56 is opened in accordance with retracting action, to release partly the compressed air into the atmosphere. Thus by absorbing reaction, a driving machine is prevented from floating.