Abstract: 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.

Abstract: The apparatus has a pointed-nose hollow cylindrical body with a closed rear portion. Disposed inside the body, so as to enable reciprocation and rotation about the axis of the body, is a stepped striker which can be locked against rotation about the axis of the body in two positions, the positions corresponding to forward and reverse movement of the apparatus.For the purpose of admitting compressed air into a forward working chamber, the striker is provided with a central passage permanently connected to a rear working chamber and at least two radial passages which provide communication between the central passage and an outer cylindrical surface of a large step of the striker. The radial passages are displaced relative to each other both circumferentially and longitudinally along the axis of the body.

Abstract: The present invention relates to pneumatic impact devices and can be used to the best advantage for making holes in compacted soils.The device is provided with a hollow casing which accommodates a stepped ram with the maximum-diameter step in its front part. This step has longitudinal channels which open at one end into a working chamber defined by the maximum-diameter step and the side walls of the casing and serving for receiving compressed air from the compressed air line, with the air moving the striker to impart a blow after which it is discharged through holes in the casing.

Abstract: A device has a cylindrical housing with a pointed front portion, which accommodates a striker separating the inner space of the housing to form a front and rear active chambers. The striker is provided with an open space at the rear end face thereof which mounts an air distributing branch connection threaded in the housing to be axially displaceable therein for reversing the device motion and adapted to admit compressed air to the active chambers and discharge it to the atmosphere therefrom thus reciprocating the striker which applies impacts to the housing. The air distributing branch connection has pipes arranged coaxially and forming longitudinal passages, of which the central passage serves to admit compressed air to the active chambers, while the annular passage between the pipes is used to discharge spent air from the active chambers.