Recovery of uncontaminated cores

Claim 1

AN IMPROVED CORING APPARATUS FOR OBTAINING AN UNCONTAMINATED CORE SAMPLE FROM THE EARTH SUBSTRATA WHICH COMPRISES IN COMBINATION A STRING OF DRILL PIPE, AN OUTER BARREL MEMBER ATTACHED TO THE LOWER END OF THE DRILL STRING AND PROVIDED WITH A CORING BIT, AN INNER CORE RECEIVING BARREL CONCENTRICALLY DISPOSED WITHIN SAID OUTER BARREL, MEANS PERMITING ROTATION OF SAID OUTER BARREL RELATIVE TO SAID INNER BARREL, A COOLING CHAMBER DISPOSED WITHIN SAID OUTER BARREL, A SPIRAL COIL CONDUIT WITHIN SAID COOLING CHAMBER AND SURROUNDING SAID INNER BARREL, FIRST CONDUIT MEANS ARRANGED TO TRANSMIT A VAPORIZABLE LIQUID REFRIGERANT FROM THE DRILL STRING TO ONE END OF SAID COIL, EXPANSION VALVE MEANS AT THE OPPOSITE END OF SAID COIL ARRANGED TO VAPORIZE SAID REFRIGERANT AND TO DISCHARGE THE VAPORS INTO SAID COOLING CHAMBER, SECOND CONDUIT MEANS FOR CONVEYING SAID VAPORS FROM SAID COOLING CHAMBER TO THE ANNULAR SPACE BETWEEN THE DRILL STRING AND THE SURROUNDING EARTH STRATA, AN AUGER ATTACHED TO THE OUTER PERIPHERY OF THE OUTER BARREL AND ARRANGED TO TRANSPORT DRILL CUTTING UPWARD FROM THE CORING BIT.