Pressure sensitive device with sealed motion transmitting lever

Claim 1

IN A PRESSURE MEASURING DEVICE: A CASING; A FLEXIBLE DIAPHRAGM DISPOSED IN SAID CASING AND FORMING WITH SAID CASING SEPARATE CHAMBERS ON OPPOSITE SIDES OF DIAPHRAGM; SAID DIAPHRAGM HAVING A ANNULAR GENERALLY U-SECTION FORMED INWARDLY OF THE PERIPHERY THEREOF OPENING INTO THE ONE OF SAID CHAMBERS NORMALLY CONTAINING FLUID UNDER HIGHER PRESSURE THAN THE OTHER CHAMBER; A DIAPHRAGM THRUST MEMBER SECURED TO SAID DIAPHRAGM INWARDLY OF SAID ANNULAR U-SECTION FREELY FLOATING WITHIN SAID CASING FOR MOVEMENT WITH THE DIAPHRAGM IN RESPONSE TO PRESSURE DIFFERENTIALS BETWEEN THE CHAMBERS AT OPPOSITE SIDES THEREOF; RESILIENT MEANS EFFECTIVELY OPPOSING MOVEMENT OF SAID DIAPHRAGM FROM ZERO POSITION; MEANS IN THE WALL OF SAID CASING PROVIDING A CIRCUMFERENTIAL KNIFE EDGE FORMING AN APERTURE THROUGH SAID WALL; A LEVER MEMBER PROJECTING THROUGH SAID APERTURE WITH A CLOSE FREE FIT; PIVOT MEANS FIXED TO SAID LEVER MEMBER ON ONE SIDE OF SAID WALL; POVIT RETAINING MEANS COOPERATING BETWEEN SAID WALL AND SAID PIVOT MEANS TO MAINTAIN SAID LEVER MEMBER IN POSITION; SEAL MEANS PROVIDING A PRESSURE SEAL BETWEEN SAID LEVER MEMBER AND SAID WALL; AND MEANS WITHIN SAID CAUSING COUPLING SAID LEVER MEMBER AND SAID DIAPHRAGM THRUST MEMBER FOR CONJOINT MOVEMENT.