Pressure responsive diaphragm operated device

Claim 1

A PRESSURE-RESPONSIVE DEVICE COMPRISING FIRST AND SECOND CASING MEMBERS; SAID FIRST CASING MEMBER PROVIDING A FIRST CAVITY AND A SECOND CASING MEMBER PROVIDING A SECOND CAVITY; A SNAP-ACTING DIAPHRAGM MEMBER POSITIONED INTERMEDIATE SAID FIRST AND SECOND CASING MEMBERS; EACH OF SAID FIRST AND SECOND CASING MEMBERS BEING SECURED TO SAID DIAPHRAGM MEMBER SEPARATES AND PERIPHERY THEREOF SO THAT SAID MEMBER SEPARATES AND SEALS SAID FIRST CAVITY FROM SAID SECOND CAVITY; SAID DIAPHRAGM MEMBER HAVING A DEFORMED PORTION THEREIN RESPONSIBLE FOR ITS SNAP ACTION; SAID FIRST CASING MEMBER PROVIDING AN ORIFICE COMMUNICATING WITH SAID FIRST CAVITY TO ADMIT FLUID UNDER PRESSURE AGAINST ONE SIDE OF SAID DIAPHRAGM TO EFFECT SNAP ACTION OF SAID DIAPHRAGM IN RESPONSE TO SAID PRESSURE IN A DIRECTION TOWARD SAID SECOND CASING MEMBER; SAID FIRST CASING MEMBER INCLUDING A FIRST CALIBRATION STOP MEMBER PROJECTING INTO SAID FIRST CAVITY FOR CALIBRATING SAID SNAP-ACTING DIAPHRAGM MEMBER, SAID FIRST CALIBRATION STOP MEMBER BEING ENGAGEABLE WITH THE DEFORMED PORTION OF SAID SNAP-ACTING DIAPHRAGM MEMBER IN ONE POSITION THEREOF FOR VARYING THE PRESSURES REQUIRED TO EFFECT SNAP ACTION THEREOF IN AT LEAST ONE DIRECTION WITHOUT DELETERIOUSLY AFFECTING THE SNAP ACTION OF THE DIAPHRAGM MEMBER; AND A SECOND CALIBRATION STOP MEMBER ADJUSTABLY MOUNTED ON THE SECOND CASING MEMBER AND ENGAGING THE DEFORMED PORTION OF THE SNAPACTING DIAPHRAGM IN A SECOND POSITION THEREOF.