Valve system for percussion drill motor

Claim 1

IN A PERCUSSION DRILL MOTOR INCLUDING A HOUSING, AN AXIALLY HOLLOW HAMMER SLIDEABLY DISPOSED WITHIN AND CLOSELY FITTING SAID HOUSING, AN AXIALLY HOLLOW ANVIL SLIDEABLY DISPOSED WITHIN AND CLOSELY FITTING SAID HOUSING ADJACENT ONE END OF SAID HAMMER, SAID HAMMER BEING RECIPROCATED BY VALVE ACTION ON A STREAM OF PRESSURE FLUID FLOWING IN THE AXIAL HOLLOW PORTIONS OF SAID HAMMER AND SAID ANVIL, THE IMPROVEMENT COMPRISING: (1) AN AXIALLY SYMMETRIC POPPET VALVE COAXIALLY AND SLIDEABLY MOUNTED WITHIN SAID HOUSING ADJACENT SAID ANVIL WITH AN AXIALLY SHORT SECTION OF MAXIMUM DIAMETER AND A LOWER BEVELED FACE EXTENDING INWARDLY FROM SAID SECTION OF MAXIMUM DIAMETER, (2) A RECESSED VALVE SEAT IN THE HOLLOW PORTION OF SAID ANVIL ADJACENT SAID HAMMER, SAID VALVE SEAT BEING BEVELED TO CORRESPOND TO SAID LOWER BEVELED FACE OF SAID VALVE AND AXIALLY ALIGNED THEREWITH, SAID SEAT BEING LOCATED BELOW THE TOP OF SAID ANVIL BY A SUBSTANTIAL AXIAL DISTANCE SUCH THAT WHEN SAID VALVE TOUCHES SAID SEAT SAID SHORT SECTION IS BELOW THE TOP OF SAID ANVIL, THE RECESS ABOVE SAID SEAT BEING SUBSTANTIALLY A RIGHT CIRCULAR CYLINDER THE DIAMETER OF WHICH IS OF ONLY SLIGHTLY GREATER DIAMETER THAN THE MAXIMUM DIAMETER OF SAID VALVE, AND (3) A RECESSED VALVE SEAT IN THE HOLLOW PORTION OF SAID HAMMER ADJACENT SAID ANVIL, SAID VALVE SEAT BEING BEVELED TO CORRESPOND TO THE UPPER SURFACE OF SAID VALVE AND AXIALLY ALIGNED THEREWITH, SAID SEAT BEING LOCATED ABOVE THE BOTTOM OF SAID HAMMER BY A SUBSTANTIAL AXIAL DISTANCE, THE RECESS BELOW SAID SEAT IN SAID HAMMER BEING SUBSTANTIALLY A RIGHT CIRCULAR CYLINDER THE DIAMETER OF WHICH IS OF ONLY SLIGHTLY GREATER DIAMETER THAN THE MAXIMUM DIAMETER OF SAID VALVE.