Method and apparatus for maintaining temperature in an enclosure

Claim 1

APPARATUS FOR MAINTAINING IN AN ENCLOSED SPACE AN ATMOSPHERE OF A GAS GENERATED FROM A CRYOGENIC LIQUID WHICH COMPRISES AN ENCLOSED CONTAINER CONTAINING SAID CRYOGENIC LIQUID UNDER PRESSURE, A FIRST CONDUIT HAVING ITS INLET END COMMUNICATING WITH THE BODY OF CRYOGENIC LIQUID IN SAID CONTAINER, A DIAPHRAGM VALVE CONTROLLING THE DISCHARGE OF CRYOGENIC LIQUID FROM SAID FIRST CONDUIT, INCLUDING A VALVE HEAD CONTROLLING SAID DISCHARGE, SAID DIAPHRAGM VALVE INCLUDING MEANS DEFINING A CONTROL CHAMBER ON ONE SIDE OF ITS DIAPHRAGM AND ONE WALL OF WHICH IS FORMED BY SAID DIAPHRAGM, MEANS RESPONSIVE TO THE TEMPERATURE IN SAID ENCLOSED SPACE FOR PRESSURIZING AND VARYING THE PRESSURE IN SAID CONTROL CHAMBER, COMPRISING A CLOSED SENSOR TUBE IN SAID ENCLOSED SPACE CONTAINING A GAS THE PRESSURE OF WHICH VARIES IN RESPONSE TO TEMPERATURE CHANGES IN SAID ENCLOSED CHAMBER, AND MEANS PLACING THE INTERIOR OF SAID SENSOR TUBE IN COMMUNICATION WITH SAID CONTROL CHAMBER, AND A SECOND CONDUIT CONNECTING THE DISCHARGE FROM SAID DIAPHRAGM VALVE TO SAID ENCLOSED SPACE.