Brake booster control valve mechanism

Claim 1

A BRAKE BOOSTER MECHANISM COMPRISING, A FLUID PRESSURE OPERATED MOTOR INCLUDING A CASING HAVING A PRESSURE DIFFERENTIAL RESPONSIVE MOVABLE WALL OPERABLE THEREIN CARRYING A FOLLOW-UP CONTROL VALVE MECHANISM CONTROLLING FLUID PRESSURE AT OPPOSITE SIDES OF THE WALL, SAID WALL HAVING AN AXIALLY DISPOSED COMPARTMENT THEREIN, A CARRIER MEMBER DIVIDING SAID COMPARTMENT INTO FIRST AND SECOND CHAMBERS AND INCLUDING AN AXIAL EXTENSION COOPERATING WITH A WALL OF SAID COMPARTMENT FORMING A THIRD CHAMBER, AN ANNULAR VALVE ELEMENT SUPPORTED ON A FLEXIBLE DIAPHRAGM MEMBER AND ENGAGEABLE WITH AN ANNULAR VALVE SEAT ON SAID EXTENSION TO SEPARATE FROM SAID THIRD CHAMBER A FOURTH CHAMBER, SAID CARRIER MEMBER HAVING AN AXIAL OPENING THERETHROUGH, A VALVE SEAT MEMBER RECIPROCABLY SLIDABLE IN SAID OPENING HAVING ONE END IN SAID THIRD CHAMBER AND PROVIDED WITH AN ANNULAR VALVE SEAT ENGAGEABLE WITH SAID VALVE ELEMENT AND THE OPPOSITE END IN SAID FIRST CHAMBER, A REACTION TRANSMISSION MEANS IN SAID FIRST CHAMBER, SPRING MEANS BETWEEN SAID REACTION TRANSMISSION MEANS AND SAID VALVE SEAT MEMBER URGING THE SAME OUT OF ENGAGEMENT THEREWITH AND TOWARD SAID VALVE ELEMENT FOR ENGAGEMENT THEREWITH, AND ADDITIONAL SPRING MEANS URGING SAID VALVE ELEMENT TOWARD SAID ANNULAR VALVE SEATS FOR ENGAGEMENT THEREWITH, PASSAGE MEANS CONNECTING SAID SECOND AND THIRD CHAMBER, AND OTHER PASSAGE MEANS CONNECTING SAID THIRD CHAMBER WITH ATMOSPHERE.