SCHLAGEND ARBEITENDE REVERSIERBARE DRUCKLUFTEINRICHTUNG

The device has a hollow cylindrical housing pointed at the front end and accommodating a hammer piston, which defines with the housing a front end work chamber and, which has at a rear end portion a cylindrical space and an open-ended radial passage. The cylindrical space receives the large portion of a stepped pipe in order to define with the hammer piston a rear end work chamber. The small portion of the pipe is received in the rear end portion of the housing for rotation about its axis within limits defined by a locking member and is connected, by means of a flexible hose, to a source of compressed air for permanent supply to the rear end work chamber of compressed air. The large portion of the stepped pipe opens the radial passage of the hammer piston at regular intervals to establish communication between the front end work chamber and the rear end work chamber, thereby enabling forward movement of the device. For reversing the movement of the device, the large portion of the pipe is provided at a front end face with a recess and at a rear end face with a projection located in alignment with the recess. The lengths of the recess and projection are such that when they are located in alignment with the radial passage, which is achieved by rotating the pipe within the limits defined by the locking member, air escapes from the front end work chamber at the position of the hammer piston in which blows are imparted to the rear end portion of the housing, and compressed air is admitted to the front end work chamber at the position of the hammer piston in which it is decelerated so as to prevent blows from being imparted to the front end portion of the housing.