Hydraulic impact hammer with overpressure and piston-overtravel protection

Abstract

The invention relates to a striking device (5) comprising a striking mechanism (8) which is driven by a pressure medium. Said device comprises a percussion piston (13) which can be displaced back and forth by means of a control device and a control valve which is embodied as a pressure shut-off valve (19) or as a stop valve, said control valve automatically stopping the striking mechanism if it exceeds a predetermined maximum value based on the working pressure controlling the inlet line, blocking the pressure line (3) or maintaining the control device in one of the and positions thereof. The inventive striking device also comprises a hydraulic catcher buffer which is used to brake the percussion piston when it exceeds a predetermined impact plane. According to the invention, the control valve must remain deactivated at least as long as the percussion piston is displaced on the hydraulic catcher buffer.

Dependencies are inferred from the claim text.