Breathing device for storage tanks

Claim 1

A BREATHING DEVICE COMPRISING IN COMBINATION; A HOUSING ADAPTED TO CONTAIN SEALING LIQUID HAVING A NORMAL LEVEL THEREIN; AN INVERTED OPEN SIDED VALVE MEMBER PIVOTALLY MOUNTED IN SAID HOUSING FOR OSCILLATING MOVEMENT FROM AN INTERMEDIATE POSITION IN OPPOSITE DIRECTIONS, SAID MEMBER BEING POSITIONED IN SAID HOUSING WHEN IT IS IN ITS INTERMEDIATE POSITION SO THAT BOTH EDGES ARE BELOW THE NORMAL LIQUID LEVEL AND THEREBY SUBMERGED IN THE SEALING LIQUID AND WHEN OSCILLATED IN ONE DIRECTION ONE EDGE IS BELOW THE NORMAL LIQUID LEVEL AND THE OTHER EDGE IS ABOVE THE NORMAL LIQUID LEVEL TO FORM A VACUUM RELIEF CHAMBER, AND WHEN OSCILLATED IN THE OTHER DIRECTION THE SAID EDGE IS RAISED ABOVE THE NORMAL LIQUID LEVEL TO PROVIDE A PRESSURE RELIEF PASSAGE, A CONDUIT EXTENDING FROM THE EXTERIOR OF SAID HOUSING THEREINTO AND TO A POINT ABOVE THE NORMAL LIQUID LEVEL AND WITHIN SAID VALVE MEMBER AND ADAPTED TO BE CONNECTED TO A SOURCE OF PRESSURE; AND A SEPARATE PIVOTALLY MOUNTED OSCILLATABLE OPERATING CHAMBER SECURED TO SAID VALVE MEMBER FOR OSCILLATING THE SAME IN THE DIRECTION, SAID OPERATING CHAMBER HAVING TWO ENDS, ONE OF WHICH IS SEALED TO THE ATMOSPHERE AND PROJECTS ABOVE THE NORMAL LIQUID LEVEL AT ALL TIMES DURING ITS OCILLATING MOVEMENTS AND THE OTHER BEING OPEN AND POSITIONED BELOW THE NORMAL LIQUID LEVEL AT ALL TIMES DURING ITS OSCILLATING MOVEMENTS; AND A SECOND CONDUIT BEING ADAPTED TO BE CONNECTED TO THE SAME SOURCE OF PRESSURE AS SAID FIRST CONDUIT AND EXTENDING INTO SAID OPERATING CHAMBER.