Automatic flow rate responsive shut-off valve

Claim 1

A VALVE COMPRISING A VALVE DISC CLOSING ONTO A VALVE SEAT IN THE DIRECTION OF THE FLUID FLOW, TWO SUPERPOSED MEMBRANES OF DIFFERENT AREAS BEING ENCLOSED IN A HOUSING MOUNTED ON THE VALVE, THE SMALLER MEMBRANE BEING IN COMMUNICATION WITH THE FLUID PRESSURE AT THE ENTRANCE (I.E. UPSTREAM) OF THE VALVE SEAT AT ALL TIMES, WHILE THE LARGER MEMBRANE IS IN COMMUNICATION WITH THE FLUID PRESSURE AT THE EXIT (I.E. DOWNSTREAM) OF THE VALVE SEAT BY MEANS OF A BY-PASS AND A THREE-WAY COCK IN SAID DOWNSTREAM SIDE, MEANS BEING PROVIDED ON THE VALVE STEM TO OPEN THE VALVE MANUALLY AGAINST THE FLUID PRESSURE AND AGAINST THE FORCE OF A SPRING SURROUNDING THE VALVE STEM, AND MEANS BEING FURTHER PROVIDED IN COMBINATION WITH THE MEMBRANES AND EXTENDING INTO THE PATH OF MOVEMENT OF THE VALVE DISC TO ENGAGE THE DISC AND MAINTAIN IT IN THE OPEN POSITION AGAINST THE ACTION OF SAID SPRING FORCE AS LONG AS THE PRESSURE IN THE UP-STREAM AND DOWN-STREAM SIDES OF THE VALVE SEAT IS SUBSTANTIALLY EQUAL, THE ACTUATION OF SAID THREE-WAY COCK BEING EFFECTED BY MEANS SENSITIVE TO THE RATE OF FLOW FIXEDLY ATTACHED TO SAID COCK, SAID LASTMENTIONED MEANS PERMITTING THE COMMUNICATION OF THE FLUID PRESSURE TO THE LARGER MEMBRANE WHEN PREDETERMINED FLOW CONDITIONS PREVAIL, WHILE WHEN THE RATE OF FLOW EXCEEDS THE PREDETERMINED RATE, SAID LAST-MENTIONED MEANS CAUSING THE COCK TO CLOSE COMMUNICATION BETWEEN THE INTERIOR OF THE VALVE AND THE LARGER MEMBRANE AND SIMULTANEOUSLY TO PROVIDE COMMUNICATION BETWEEN THE SPACE ABOVE THE LARGER MEMBRANE AND THE ATMOSPHERE, WHEREBY THE FLUID PRESSURE FROM ABOVE THE LARGER MEMBRANE IS RELEASED TO THE ATMOSPHERE.