Pneumatic measuring apparatus

Claim 1

PNEUMATIC MEASURING APPARATUS COMPRISING A CONNECTION TO A PROCESS VARIABLE WHOSE PEAK PRESSURE IS TO BE MEASURED, A CONNECTION TO A SOURCE OF FLUID UNDER PRESSURE, A NORMALLY CLOSED FLUID OUTLET CONNECTION, A FLUID PRESSURE RESPONSIVE MEMBER CONNECTED TO SAID OUTLET CONNECTION, A RELAY COMPRISING A FIRST HOUSING SECTION, A SECOND HOUSING SECTION, AND DIAPHRAGM ASSEMBLY INTERPOSED BETWEEN SAID SECTIONS AND HAVING OPPOSITE FACE PORTIONS, EACH OF SAID HOUSING SECTIONS HAVING A CHAMBER THEREIN BOUNDED BY ONE OF SAID FACE PORTIONS, ONE OF SAID CHAMBERS HAVING SAID PROCESS VARIABLE CONNECTION IN COMMUNICATION THEREWITH, AND THE OTHER OF SAID CHAMBERS HAVING SAID OUTLET CONNECTION IN COMMUNICATION THEREWITH, THE OTHER OF SAID CHAMBERS HAVING A FLUID CONNECTION WITH WHICH SAID CONNECTION TO SAID SOURCE IS CONNECTED, A VALVE MEMBER INTERPOSED BETWEEN SAID CONNECTION TO SAID SOURCE AND SAID OTHER CHAMBER AND CONTROLLED BY THE POSITIONING OF SAID DIAPHRAGM ASSEMBLY, SAID VALVE MEMBER BEING MOVABLE TO CLOSED POSITION, AND AN ADJUSTABLE MOTION LIMITING MEMBER FOR LIMITING THE MOTION OF SAID DIAPHRAGM ASSEMBLY BEYOND A POSITION TO CLOSE SAID VALVE MEMBER THEREBY TO LIMIT THE EXPANSION OF PRESSURE FLUID DELIVERED BY SAID VALVE TO SAID OUTLET CONNECTION.