Ground burrowing device

Claim 1

A GROUND BURROWING DEVICE HAVING ALL MOVABLE DRIVING ELEMENTS ENCLOSED THEREIN, SAID DEVICE COMPRISING IN COMBINATION: (A) AN ELONGATED OUTER CASING HAVING A TAPERING FORWARD END TO FACILITATE DRIVING THROUGH THE GROUND, SAID CASING HOUSING AN ELONGATED CHAMBER; (B) A PISTON RECIPROCABLE IN SAID CHAMBER AND DIVIDING THE SAID CHAMBER INTO A REAR CHAMBER, AND A FRONT CHAMBER, OF CHANGEABLE VOLUME; (C) AN ANVIL POSITIONED AT ONE END OF THE SAID ELONGATED CHAMBER AND ADAPTED TO BE STRUCK BY SAID PISTON; (D) A COMPRESSED AIR CONDUIT LEADING FROM THE REAR END OF SAID DEVICE AND ADAPTED TO BE CONNECTED TO AN EXTRANEOUS SOURCE OF COMPRESSED AIR; (E) A COMPRESSED AIR DUCT CONNECTING THE COMPRESSED AIR CONDUIT WITH THE CHAMBER OF CHANGEABLE VOLUME IN THE SAID ONE END OF THE DEVICE; (F) A COMPRESSED AIR PASSAGEWAY CONNECTING THE COMPRESSED AIR CONDUIT WITH THE CHAMBER OF CHANGEABLE VOLUME IN THE OTHER END OF SAID DEVICE; (G) VALVE MEANS WITHIN THE SAID PASSAGEWAY ADAPTED TO OPEN AND CLOSE THE PASSAGEWAY AUTOMATICALLY RESPONSIVE TO CHANGES IN THE PRESSURE IN THE LAST SAID CHAMBER OF CHANGEABLE VOLUME, THE VALVE BEING OPENED BY INCREASED PRESSURE IN SAID CHAMBER; (H) AN EXHAUST CONDUIT LEADING FROM THE REAR END OF SAID DEVICE TO THE ATMOSPHERE; AND (I) A PORT CONNECTING SAID EXHAUST CONDUIT WITH THE LAST SAID CHAMBER OF CHANGEABLE VOLUME AND ADAPTED TO BE OPENED BY THE PISTON AS THE PISTON APPROACHES THE ANVIL AND TO BE CLOSED THEREBY AS IT MOVES AWAY FROM THE ANVIL.