Pneumatic tooth for earth excavator

Claim 1

IN A PNEUMATIC TOOL, AN ELONGATED HOLLOW BODY, A TOOTH ASSEMBLY SLIDABLY MOUNTED WITHIN THE FORWARD END PORTION OF THE BODY AND AXIALLY EXTENSIBLE AND RETRACTIBLE RELATIVE THERETO, AN IMPACT RECEIVING SURFACE ON THE INNER END OF SAID TOOTH ASSEMBLY, PLUNGER MEANS SLIDABLE WITHIN SAID BODY AND SELECTIVELY ENGAGEABLE WITH SAID IMPACT RECEIVING SURFACE, AN EXPANSION CHAMBER REARWARD OF SAID PLUNGER MEANS, MEANS FOR CONVEYING COMPRESSED AIR INTO SAID EXPANSION CHAMBER, SUPPLY VALVE MEANS FOR SELECTIVELY ALLOWING PASSAGE OF THE COMPRESSED AIR INTO THE EXPANSION CHAMBER, MEANS OPERATIVELY CONNECTING THE TOOTH ASSEMBLY WITH THE SUPPLY VALVE MEANS FOR CONTROLLING THE OPENING AND CLOSING OF SAID SUPPLY VALVE MEANS ON MOVEMENT OF THE TOOTH ASSEMBLY BEYOND PREDETERMINED POINTS, AND CONTROL VALVE MEANS OPERATIVE IN RESPONSE TO A FORWARD MOVEMENT OF SAID PLUNGER MEANS FOR SEALING SAID EXPANSION CHAMBER AND TRAPPING COMPRESSED AIR THEREIN FOR A SUBSEQUENT EXPANSION THEREOF AND A CORRESPONDING FORWARD DRIVING OF SAID PLUNGER MEANS.