Sliding pressure control valve for pneumatic hammer drill

United States Patent

August 30, 2011
View the Complete Patent at the US Patent & Trademark Office
Sliding Pressure Control Valve for Pneumatic Hammer Drill
A pneumatic device control apparatus and method comprising a ported valve slidably fitted over a feed tube of the pneumatic device, and using a compliant biasing device to constrain motion of the valve to provide asymmetric timing for extended pressurization of a power chamber and reduced pressurization of a return chamber of the pneumatic device. The pneumatic device can be a pneumatic hammer drill.
February 3, 2009
173/1 ; 173/13; 173/135; 173/136; 173/14; 173/15; 173/16; 173/17; 173/178; 173/78; 173/80; 173/91; 251/344; 251/348; 91/22; 91/325;
E21B 4/14 (20060101);
173/13-17,91,178,78,80,135-136,1 91/222,325 251/344,348
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT The Government has rights to this invention pursuant to Contract No. DE-AC04-94AL85000 awarded by the U.S. Department of Energy.