Snap acting relief valve

Claim 1

A RELIEF COMPRISING A BODY ADAPTED TO BE MOUNTED IN THE WALL OF PRESSURIZED EQUIPMENT, A DIAPHRAGM HELD IN THE BODY PORTION WITH OPPOSITE FACES OF SAID DIAPHRAGM ARRANGED TO BE EXPOSED RESPECTIVELY TO AMBIENT ATMOSPHERIC PRESSURE AND TO THE INTERNAL PRESSURE OF THE PRESSURIZED EQUIPMENT, A VALVE OPERATING MEMBER SECURED TO SAID DIAPHRAGM, A RESILIENT MEMBER MOUNTED IN THE VALVE BODY IN A SLIGHTLY BOWED CONDITION AND SUBSTANTIALLY PARALLEL WITH SAID DIAPHRAGM AND ENGAGED BY SAID VALVE OPERATING MEMBER, SO AS TO BE SNAPPED OVER-CENTER BETWEEN ALTERNATIVE POSITIONS BY ACTION OF THE VALVE OPERATING MEMBER, A GAS OUTLET PASSAGE IN THE BODY PORTION, A TILT VALVE MOUNTED IN SAID OUTLET PASSAGE, AN ACTUATING MEMBER FOR SAID TILT VALVE AND AN OPERATIVE CONNECTION BETWEEN SAID ACTUATING MEMBER AND SAID RESILIENT MEMBER, WHEREBY IN ONE OF SAID ALTERNATIVE POSITIONS OF THE RESILIENT MEMBER THE TILT VALVE IS CAUSED TO OPEN BY SAID ACTUATING MEMBER AND IN THE OTHER POSITION, THE TILT VALVE REMAINS CLOSED AND RESILIENT MEANS FOR APPLYING A RESTORING FORCE TO BE BOWED RESILIENT MEMBER AFTER A PREDETERMINED REDUCTION OF THE PRESSURE DIFFERENCE ACROSS THE DIAPHRAGM.