Automatic diaphragm actuated valve

Claim 1

IN A COMBINATION COMPRISING A SUPPLY LINE PRESSURE ACTUATED MAIN VALVE CONTROLLED BY A SECONDARY VALVE IN WHICH THE MAIN VALVE EMBODIES A BOWL DIVIDED BY A PARTITION INTO A HIGH PRESSURE INTAKE SIDE AND A LOW PRESSURE OUTLET SIDE, THE PARTITION INCLUDING A DISC VALVE SEAT ENCOMPASSING A FLUID PASSAGE FROM THE INTAKE SIDE TO THE OUTLET SIDE, AND A DISC VALVE HEAD IN COOPERATING ASSOCIATION WITH THE VALVE SEAT TO CLOSE OR OPEN THE PASSAGE, ACTUATING AND CONTROL MEANS COMPRISING A HOUSING AXIALLY ADJACENT THE VALVE SEAT AND SUBSTANTIALLY HERMETICALLY COUPLED WITH THE BOWL, A DIAPHRAGM MEMBER OF GREATER AREA THAN THE AREA OF THE VALVE HEAD AXIALLY ALIGNED WITH THE VALVE SEAT AND TRANSVERSELY SUBSTANTIALLY HERMETICALLY BRIDGING SAID HOUSING AND DIVIDING THE LATTER TO FORM UPPER AND LOWER CHAMBERS, A RECIPROCABLE HOLLOW RIGID VALVE STEM MOUNTING THE VALVE HEAD AND EXTENDING IN AXIAL ALIGNMENT THEREWITH FROM THE INTAKE SIDE THROUGH THE LOWER CHAMBER AND DIAPHRAGM MEMBER AND INTO THE UPPER CHAMBER AND PROVIDING A RELATIVELY SMALL CONTINUOUSLY OPEN FLUID COMMUNICATION FROM THE INTAKE SIDE TO THE UPPER CHAMBER, A THRUST COLLAR ON THE DIAPHRAGM MEMBER AND A SHOULDER ON THE VALVE STEM SAID COLLAR AND SHOULDER BEING INTERENGAGEABLE FOR TRANSMITTING DOWNWARD THRUST OF THE DIAPHRAGM MEMBER TO THE VALVE STEM FOR CLOSING THE MAIN VALVE, SAID UPPER CHAMBER BEING PROVIDED WITH RELATIVELY LARGE FLUID COMMUNICATION MEANS EXTENDING FROM THE UPPER CHAMBER TO THE LOWER CHAMBER, THE UPPER CHAMBER BEING OTHERWISE SUBSTANTIALLY FLUID TIGHT, A SECONDARY SOLENOID OPERATED SHUT OFF VALVE IN THE LATTER FLUID COMMUNICATION MEANS, THE HOUSING INCLUDING A CIRCULAR GUIDE BORE FOR THE VALVE STEM EXTENDING FROM THE LOWER CHAMBER TO THE OUTLET SIDE, THE VALVE STEM EMBODYING A LENGTH OF POLYGONAL CROSS SECTION SLIDABLE IN THE BORE WITH ANGULAR EDGES OF THE STEM ENGAGING THE BORE AND THE SPACE BETWEEN FLAT PLANE SURFACES OF THE STEM AND THE CIRCULAR SURFACE OF THE BORE AFFORDING RELATIVELY LARGE FLUID COMMUNICATION FROM THE LOWER CHAMBER TO THE OUTLET SIDE AND THE LOWER CHAMBER BEING OTHERWISE SUBSTANTIALLY FLUID TIGHT, WHEREBY WHEN THE SECONDARY VALVE IS CLOSED SUPPLY LINE PRESSURE FROM THE INTAKE SIDE IS COMMUNICATED THROUGH THE VALVE STEM INTO THE UPPER CHAMBER AND ACTS UPON THE DIAPHRAGM MEMBER TO THRUST THE SAME DOWNWARDLY AND THROUGH THE VALVE STEM TO HOLD THE VALVE HEAD CLOSED UPON THE VALVE SEAT, AND WHEN THE SECONDARY VALVE IS OPENED FLUID BLEEDS FROM THE UPPER CHAMBER TO THE LOWER CHAMBER AND FROM THE LOWER CHAMBER TO THE OUTLET SIDE FASTER THAN FLUID CAN ENTER THE UPPER CHAMBER THROUGH THE VALVE STEM AND SUPPLY LINE PRESSURE IS THUS REDUCED IN THE UPPER CHAMBER SO THAT SUPPLY LINE PRESSURE ACTING UPON THE VALVE HEAD LIFTS IT TO OPEN POSITION.