Abstract: The present invention relates to building and to mining, more particularly o an apparatus for impact action designed for trenchless laying of new underground communications and for reconstruction of existing communications, the apparatus comprising a body, a striker with a through central channel, the striker positioned inside the body with the possibility of performing reciprocal movement, a front chamber formed between the body and striker, a rear chamber formed between the body and the striker, an air distribution system comprising channels for the inlet of compressed air into the chambers and channels for the exhaust of spent air from the chambers, an air conduit, and in which in accordance with the invention the air distribution system is provided autonomously for each of the aforesaid chambers.

Abstract: The apparatus consists of a hollow body wherein there is contained a striker which divides the space inside the body into a forward operating chamber and a rear exit chamber. The striker is provided with ports for admitting compressed air into the forward operating chamber and for allowing the emission of spent air from the chamber. The striker is also provided with an interior space, the rear end face of said striker being left open. Said hollow body includes passages and a pipe for placing said interior space of said striker in communication with a source of compressed, the pipe being positioned for longitudinal travel relative to the body.

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.

Abstract: The machine has a braking arrangement for retaining it against rearward motion and rotation and includes a housing accommodating therein a hammer reciprocable in operation of the machine and adapted to strike the head part of the housing, the latter having a drilling tool rigidly connected thereto. The tail part of the housing supports a sleeve rigidly connected with the braking arrangement. The housing and the sleeve are connected so that the housing is rotatable and axially displaceable relative to the sleeve. The drilling tool rotating mechanism is positioned intermediate the sleeve and the housing and includes a helicoidal couple made up by a helicoidally threaded rod rigidly secured to the housing and a nut, the mechanism further including a freewheeling clutch of which the movable cage is made integral with the nut.

Abstract: A percussive machine having an impact mechanism accommodated to a housing with a hammer piston imparting blows to a rock-destroying member. There is provided an air-supply duct for supplying compressed air to the impact mechanism and to the hole face. In order to prevent the machine from moving away from the hole face during the operation, the housing is provided with an elastic tubular member having a space in constant communication with the air supply duct.