An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure.
CONTRACTUAL ORIGIN OF THE INVENTION
The United States Government has rights in this invention disclosed under contract number DE-AC07-84ID12435 between the U.S. Department of Energy and Westinghouse Idaho Nuclear Company, now contract number DE-AC07-94ID13223 with Lockheed Idaho Technologies Company.