Pressure differential operated brake booster device

Claim 1

IN A FLUID PRESSURE BOOSTER-TYPE MOTOR DEVICE COMPRISING A CYLINDRICAL CASING HAVING SPACED END WALLS PROVIDED WITH CENTRAL OPENINGS, RESPECTIVELY, AND A PRESSUREDIFFERENTIAL RESPONSIVE UNIT MOVABLE THEREIN FROM NORMAL POSITION AND WHICH DIVIDES THE INTERIOR OF SAID CASING INTO A CONSTANT PRESSURE CHAMBER AND A VARIABLE PRESSURE CHAMBER WITH RESPECT TO SAID END WALLS, THE FORMER CHAMBER BEING CONNECTED TO A SOURCE OF VACUUM PRODUCTION, THE IMPROVEMENT WHICH COMPRISES: FOLLOW-UP CONTROL VALVE MECHANISM MOUNTED IN PART ON SAID UNIT, SAID VALVE MECHANISM COMPRISING: AN OUTER VALVE ELEMENT CHARACTERIZED BY A TUBULAR WALL; AN ELONGATED VALVE ACTUATOR INCLUDING A CYLINDRICAL VALVULAR PORTION IN INTERFITTING RELATIONSHIP WITH RESPECT TO SAID TUBULAR VALVE ELEMENT; COMPLEMENTAL WORKING SURFACES BETWEEN SAID TUBULAR ELEMENT AND VALVULAR PORTION, SAID SURFACES BEING NORMALLY SPACED FROM EACH OTHER; AN INTERNAL ANNULAR VACUUM CHAMBER INDENTED IN THE WORKING SURFACE ON THE TUBULAR VALVE ELEMENT AND HAVING CONTINUOUS COMMUNICATION WITH SAID SOURCE OF VACUUM; CONDUIT MEANS INCORPORATED BETWEEN SAID PRESSURE-RESPONSIVE UNIT AND SAID TUBULAR VALVE ELEMENT FOR MAINTAINING COMMUNICATION BETWEEN SAID CONSTANT PRESSURE CHAMBER AND SAID VACUUM CHAMBER; AN AIRVACUUM CHANNEL TRANSVERSELY INCORPORATED THROUGH A PORTION OF THE WALL OF SAID TUBULAR VALVE LEMENT; AN AIR SLOT TRANSVERSELY INCORPORATED IN THE WORKING SURFACE ON SAID VALVULAR PORTION AND WHICH IS LONGITUDINALLY SPACED FROM THE SAID FIRST-NAMED WORKING SURFACE THEREON, SAID AIR SLOT BEING NORMALLY OUT OF REGISTRY WITH THE AFORESAID AIR-VACUUM CHANNEL WHEN SAID WORKING SURFACES ARE IN NORMALLY SPACED RELATIONSHIP AFORESAID; AN AIR PASSAGE SYSTEM INCORPORATED IN SAID VALVE ACTUATOR FOR CONVEYING AIR AT ATMOSPHERIC PRESSURE; LONGITUDINALLY DISPOSED BRACKET MEANS MOUNTED ON SAID PRESSURE-RESPONSIVE UNIT WHOLLY WITHIN SAID VARIABLE PRESSURE CHAMBER FOR STABILIZING THE SAID TUBULAR VALVE ELEMENT TO HAVE AXIAL UNITARY MOVEMENT WITH SAID PRESSU-RERESPONSIVE UNIT, AND TO ACCOMMODATE LIMITED RELATIVE AXIAL MOVEMENT OF SAID TUBULAR VALVE ELEMENT; A PAIR OF COOPERATING ABUTMENT-ENGAGING PORTIONS OF SAID BRACKET MEANS AND TUBULAR VALVE ELEMENT, RESPECTIVELY, FOR DEFINING THEIR RELATIVE NORMAL POSITIONS, WHEN ENGAGED; ANOTHER PAIR OF COOPERATING ABUTMENT-ENGAGING PORTIONS ON SAID BRACKET MEANS AND MOTOR CASING, RESPECTIVELY, FOR DEFINING THE NORMALY POSITION OF SAID PRESSURE-RESPONSIVE UNIT, WHEN ENGAGED; SPRING ACTIVATED SEALING MEANS INCORPORATED BETWEEN SAID MOTOR CASING AND VALVE ACTUATOR TO PREVENT LEAKAGE FROM SAID CONSTANT AND VARIABLE PRESSURE CHAMBVER TO THE EXTERIOR OF SAID MOTOR CASING, AND TO BIAS SAID VALVE ACTUATOR TOWARD NORMAL POSITION; AND OPERATOR-OPERATED MEANS OPERATABLE FROM NORMAL POSITION TO DISPLACE SAID VALVE ACTUATOR RELATIVELY, FROM ITS NORMAL POSITION, TO SAID TUBULAR VALVE ELEMENT TO SEQUENTIALLY CLOSE THE SPACE AFORESAID BETWEEN SAID WORKING SURFACES AS A FUNCTION OF FIRST DISPOSING THE LATTER IN OVERLAPPING RELATIONSHIP, AND THEN PLACING SAID AIR-VACUUM CHANNEL IN COMMUNICATION WITH THE ATMOSPHERE AS A FUNCTION OF DISPOSING SAID AIR SLOT IN COMMUNICATION WITH SAID AIR-VACUUM CHANNEL THEREBY CREATING DIFFERENTIAL PRESSURES WITHIN SAID CONSTANT AND VARIABLE PRESSURE CHAMBERS TO ACTIVATE SAID PRESSURE-RESPONSIVE UNIT TO PERFORM WORK.