Power brake booster

Claim 1

IN A VACUUM SUSPENDED POWER BRAKE BOOSTER UNIT, THE COMBINATION OF, A POWER CHAMBER, A MOVABLE WALL IN SAID POWER CHAMBER DIVIDING THE SAME INTO TWO COMPARTMENTS THE FIRST OF WHICH IS CONTINUOUSLY MAINTAINED AT SUBATMOSPHERIC PRESSURE AND THE SECOND OF WHICH IS SUBJECT TO SUBATMOSPHERIC PRESSURE VARIABLE TO ATMOSPHERIC PRESSURE, VALVE MEANS CONTROLLING ADMISSION OF ATMOSPHERIC PRESSURE TO SAID SECOND COMPARTMENT TO EFFECT PRESSURE VARIATION THEREIN TO MOVE SAID MOVABLE WALL THEREBY, ATMOSPHERE PASSAGE MEANS CONDUCTING AIR TO SAID VALVE MEANS, A MASTER CYLINDER ON A WALL OF SAID FIRST COMPARTMENT AND HAVING AN OPEN END SUBJECT TO THE SUBATMOSPHERE PRESSURE IN SAID FIRST COMPARTMENT, A MASTER CYLINDER PISTON RECIPROCABLE IN SAID CYLINDER AND HAVING ONE END SUBJECT TO THE SUBATMOSPHERIC PRESSURE IN SAID FIRST COMPARTMENT, MEANS BETWEEN SAID PISTON AND SAID MOVABLE WALL TO EFFECT MOVEMENT OF SAID PISTON IN SAID CYLINDER, FIRST AND SECOND SEAL MEMBERS BETWEEN SAID CYLINDER AND SAID PISTON AT SAID ONE END THEREOF SPACED AXIALLY OF THE PISTON, ATMOSPHERE PASSAGE MEANS IN SAID PISTON TERMINATING AT THE PERIPHERY OF SAID PISTON BETWEEN SAID FIRST AND SECOND SEAL MEMBERS, AND ADDITIONAL PASSAGE MEANS CONNECTING SAID LAST-MENTIONED PASSAGE MEANS WITH SAID FIRST-MENTIONED PASSAGE MEANS TO PROVIDE A COMMON SOURCE FROM WHICH ATMOSPHERIC AIR IS SUPPLIED TO SAID VALVE MEANS AND SECOND-MENTIONED PASSAGE MEANS.