Precision vacuum controller

Claim 1

A VACUUM CONTROL VALVE INCLUDING: (A) A HOUSING DEFINING A CHAMBER THEREIN; (B) A SUCTION CONDUIT HAVING A SEALED END COMMUNICATING WITH SAID CHAMBER AND HAVING A GENERALLY ARCUATE DIAMETRICALLY ALIGNED PASSAGE THROUGH THE WALLS THEREOF TO PROVIDE VALVE SEATS AND TO PROVIDE COMMUNICATION BETWEEN THE INTERIOR THEREOF AND SAID CHAMBER; (C) AN INLET COMMUNICATING WITH SAID CHAMBER; (D) A VALVE MEMBER ARRANGED FOR SEALING WITH SAID SEATS INCLUDING: (1) A PAIR OF LONGITUDINALLY SPACED GENERALLY ARCUATE SEALING PORTIONS RECEIVABLY INTO SAID SEATS FOR SEALING THEREWITH AGAINST THE OUTER PERIPHERY THEREOF; (2) AN OPENING PORTION ADJACENT EACH OF SAID SEALING PORTIONS BEING TAPERED TO PROVIDE PROGRESSIVELY INCREASING COMMUNICATION BETWEEN THE INLET AND SAID CHAMBER; (3) A PLURALITY OF SLOTS EXTENDING LONGITUDINALLY OF SAID VALVE MEMBER ARRANGED ON ONE OF SAID ARCUTE SEALING PORTIONS AND EXTENDING THEREFROM ONTO THE ADJACENT TAPERED PORTION, THE ENDS OF AT LEAST CERTAIN OF THE SLOTS ON THE ARCUATE PORTION BEING SPACED LONGITUDINALLY OF THE VALVE TO PROVIDE A PLURALITY OF PROGRESSIVELY INCREASING AND SUCCESSIVELY OPENING COMMUNICATION PASSAGES AS THE VALVE IS MOVED THROUGH SAID SEATS SUCH THAT THE ENDS OF THE SLOTS MAY BE ARRANGED RESPECTIVELY ON EITHER SIDE OF THE WALL OF THE SUCTION CONDUIT AFFORDING THE ONLY COMMUNICATION BETWEEN THE SUCTION CONDUIT AND THE CHAMBER; (E) A CONTROL CHAMBER DEFINED BY SAID HOUSING AND HAVING A PRESSURE RESPONSIVE DIAPHRAGM MEMBER THEREIN, SAID DIAPHHRAGM BEING CONNECTED TO SAID VALVE MEMBER FOR ACTUATION THEREBY; AND (F) MEANS FOR APPLYING VALVE POSITIONING PRESSURE TO SAID DIAPHRAGM FOR INITIALLY OPENING THE SAME.