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: A characteristic feature of the present invention is that a damping unit is rovided between the casing, impact tool and elements of a pneumatic hammer. The damping unit may have a different design.