Vacuum modulator

Claim 1

A VACUUM MODULATOR ASSEMBLY COMPOSED OF AN ASSEMBLY OF FIVE SUBASSEMBLIES INCLUDING LOWER CASE, YOKE, BELLOWS, DIAPHRAGM AND UPPER CASE SUBASSEMBLIES, RESPECTIVELY, SAID LOWER CASE SUBASSEMBLY COMPRISING A LOWER CASE OF GENERALLY CYLINDRICAL CONFIGURATION HAVING AN ADAPTER SECURED TO AN END WALL OF SAID LOWER CASE, AN OPENING THROUGH SAID ADAPTER FOR RECEIVING MECHANISM TO BE CONTROLLED BY SAID MODULATOR, SAID YOKE ASSEMBLY COMPRISING A GENERALLY U-SHAPED YOKE HAVING A BASE AND A PAIR OF SPACED ARMS EXTENDING FROM SAID BASE, A GUIDE SECURED TO SAID BASE, SAID MECHANISM TO BE CONTROLLED INCLUDING AXIALLY MOVABLE MEANS EXTENDING THROUGH SAID ADAPTER OPENING INTO CONTACT WITH SAID GUIDE, SAID YOKE ASSEMBLY COMPRISING A BELLOWS AND FIRST AND SECOND END PLATES SECURED TO SAID BELLOWS AND FORMING WITH SAID BELLOWS AND EVACUATED CHAMBER WITHIN SAID BELLOWS, SAID DIAPHRAGM SUBASSEMBLY COMPRISING A DIAPHRAGM PROTECTOR, A DIAPHRAGM AND A DIAPHRAGM CONNECTOR ASSEMBLED TO EACH OTHER, SAID UPPER CASE SUBASSEMBLY INCLUDING A GENERALLY CYLINDRICAL SHAPED UPPER CASE AND A HOLLOW NIPPLE SECURED TO ONE END OF SAID CASE, MEANS ON SAID LOWER CASE COACTING WITH SAID FIRST BELLOWS END PLATE FOR PREVENTING AXIAL MOVEMENT OF SAID FIRST END PLATE RELATIVE TO SAID LOWER CASE, SAID YOKE ARMS EXTENDING PARALLEL TO SAID BELLOWS AND GRIPPING SAID SECOND END PLATE, SAID DIAPHRAGM CONNECTOR INCLUDING A FLANGE GRIPPING SAID SECOND END PLATE, SAID UPPER CASE BEING SECURED TO SAID LOWER CASE AND GRIPPING THE PERIPHERY OF SAID DIAPHRAGM BETWEEN SAID LOWER AND UPPER CASES SUCH THAT SAID DIAPHRAGM AND UPPER CASE FORM A SECOND CHAMBER ADAPTED TO BE CONNECTED TO A SOURCE OF VARIABLE VACUUM, SAID DIAPHRAGM ASSEMBLY, SAID YOKE AND SAID SECOND BELLOWS END PLATE BEING MOVABLE AS A UNIT, A SPRING SEAT DISPOSED IN SAID SECOND CHAMBER, A CALIBRATING SPRING ACTING UPON SAID DIAPHRAGM PROTECTOR, ADJUSTABLE MECHANISM IN SAID HOLLOW NIPPLE AND CONTACTING SAID SPRING SEAT FOR VARYING THE EFFECTIVE FORCE OF SAID CALIBRATING SPRING, AND A PASSAGE THROUGH SAID ADJUSTABLE MECHANISM FOR ADMITTING VACUUM FROM SAID VACUUM SOURCE TO SAID SECOND CHAMBER.