Power brake booster

Claim 1

IN A POWER BOOSTER, A HOUSING HAVING A MOVABLE POWER WALL THEREIN DIVIDING SAID HOUSING INTO A VARIABLE PRESSURE CHAMBER AND A CONSTANT PRESSURE CHAMBER, A FIRST SOURCE OF CONSTANT FIRST PRESSURE AND A SECOND SOURCE OF A SECOND PRESSURE DIFFERENT FROM THE FIRST PRESSURE FROM THE FIRST SOURCE, VALVE MEANS FOR SELECTIVELY ADMITTING SAID FIRST AND SECOND PRESSURES INTO SAID VARIABLE PRESSURE CHAMBER TO CONTROL BOOSTER POWER AND INCLUDING A NORAMLLY SEATED FIRST PRESSURE FIRST CONTROL VALVE AND A NORMALLY UNSEATED SECOND PRESSURE SECOND CONTROL VALVE AND VALVE SEAT MEANS FOR SAID VALVES, MEANS FOR MOVING SAID FIRST VALVE AND SAID VALVE SEAT MEANS RELATIVE TO SAID SECOND VALVE TO SEAT SAID SECOND VALVE ON SAID VALVE SEAT MEANS AND FOR FURTHER MOVING SAID FIRST VALVE RELATIVE TO SAID SAID VALVE SEAT MEANS AND SAID SECOND VALVE TO UNSEAT SAID FIRST VALVE, SAID MOVING MEANS COMPRISING A MANUALLY MOVABLE MEMBER AND A COMPRESSION SPRING RECEIVED IN FORCE TRANSMITTING RELATION BETWEEN SAID MANUALLY MOVABLE MEMBER AND SAID FIRST VALVE.