Oxygen supply systems

Claim 1

A LIQUID GAS CONVERTER SYSTEM INCLUDING AN INSULATED CONTAINER HAVING LIQUID AND GAS PHASE SECTIONS, A PRESSURE BUILD-UP CIRCUIT COMPRISING A BUILD-UP CONDUIT INTERCONNECTING SAID GAS AND SAID LIQUID PHASES AND CONTAINING IN SERIES A HEAT EXCHANGER AND A PRESSURE CLOSING VALVE HAVING A SEAT AND CO-OPERATING CLOSURE MEMBER, SAID BUILD-UP CONDUIT HAVING ITS LIQUID TAKE-OFF POINT POSITIONED IN SUCH A MANNER THAT A PREDETERMINED LIQUID GAS RESERVE REMAINS BELOW SAID LIQUID TAKE-OFF POINT UPON THE LIQUID LEVEL IN SAID CONVERTER RENDERING SAID BUILD-UP CIRCUIT INOPERATIVE, WHEREBY SAID LIQUID GAS REVERSE IS USED AT A LOWER PRESSURE THAN THE PRESSURE PREVIOUSLY MAINTAINED BY SAID BUILD-UP CIRCUIT, PASSAGE MEANS FOR CONVEYING OXYGEN FROM SAID CONTAINER TO AT LEAST TWO POINTS OF USE, AND MEANS FOR AUTOMATICALLY CLOSING THE PASSAGE MEANS TO ONE OF SAID POINTS OF USE WHEN SAID BUILD-UP CIRCUIT IS RENDERED INOPERATIVE DUE TO THE LIQUID LEVEL FALLING BELOW SAID TAKE-OFF POINT.