Pressure responsive device

Claim 1

A PRESSURE RESPONSIVE DEVICE COMPRISING A CASING, A WALL DIVIDING SAID CASING INTO FIRST AND SECOND COMPARTMENTS, SAID WALL BEING PROVIDED WITH A PASSAGEWAY AND AN OPENING CONNECTING SAID FIRST AND SECOND COMPARTMENTS, A VALVE FOR VARYING THE EFFECTIVE SIZE OF SAID PASSAGEWAY, A DIAPHRAGM EXTENDING ACROSS SAID FIRST COMPARTMENT SPACED FROM SAID WALL AND DIVIDING SAID FIRST COMPARTMENT INTO FIRST AND SECOND CHAMBERS, SAID FIRST CHAMBER LYING BETWEEN SAID WALL AND SAID DIAPHRAGM, DAMPING LIQUID FILLING SAID FIRST CHAMBER AND SAID PASSAGEWAY, SAID SECOND CHAMBER BEING PROVIDED WITH AN OPENING COMMUNICATING WITH SAID SECOND CHAMBER TO ADMIT TO SAID SECOND CHAMBER A PRESSURE APPLYING FLUID TO CAUSE FLEXING OF SAID DIAPHRAGM, A SPINDLE MOUNTED IN SAID CASING AND EXTENDING SLIDABLY THROUGH SAID OPENING IN SAID WALL, SAID SPINDLE BEING FASTENED TO SAID DIAPHRAGM AND LONGITUDINALLY MOVABLE BY FLEXING OF SAID DIAPHRAGM, FIRST AND SECOND COLLARS FIXED TO SAID SPINDLE IN SAID SECOND COMPARTMENT AND SPACED ONE FROM THE OTHER, A MEMBER IN SAID SECOND COMPARTMENT HAVING AN ADJUSTABLE MOUNTING TO SAID CASING POSITIONING SAID MEMBER ADJACENT SAID SPINDLE BETWEEN SAID COLLARS, A FIRST AND A SECOND SPRING IN SAID SECOND COMPARTMENT POSITIONED WITH ONE END OF EACH SAID SPRING BEARING ON SAID MEMBER, SAID SPRINGS EXTENDING IN OPPOSITE DIRECTIONS FROM SAID MEMBER WITH THE OTHER ENDS OF SAID FIRST AND SECOND SPRINGS BEARING ON SAID FIRST AND SECOND COLLARS RESPECTIVELY TO EXERT OPPOSING FORCES ON SAID SPIN-