Dual passage thermostatic valve

Claim 1

IN A CONTROL DEVICE, THE COMBINATION COMPRISING A HOUSING HAVING AN INTERNAL CAVITY DEFINING A CHAMBER, OUTLET MEANS FOR SAID HOUSING COMMUNICATING WITH SAID CHAMBER, INLET MEANS FOR SAID HOUSING COMMUNICATING WITH A PNEUMATIC SOURCE AND INCLUDING A FIRST PASSAGEWAY LEADING TO SAID CHAMBER, A SECOND PASSAGEWAY IN SAID HOUSING HAVING ONE END LEADING TO SAID CHAMBER AND HAVING ANOTHER END COMMUNICATING WITH THE ATMOSPHERE, A SINGLE VALVE ELEMENT MOVABLY DISPOSED IN SAID CHAMBER FOR ALTERNATE CONTROL OF SAID FIRST AND SECOND PASSAGEWAYS, LEVER MEANS IN SAID HOUSING FOR EFFECTING MOVEMENT OF SAID VALVE ELEMENT BETWEEN ALTERNATE CONTROLLING POSITIONS, TEMPERATURE RESPONSIVE MEANS INCLUDING A MOVABLE PORTION ENGAGING SAID LEVER MEANS WHEREBY SAID VALVE ELEMENT IS MOVED IN RESPONSE TO TEMPERATURE VARIATIONS, AND CHECK VALVE MEANS IN SAID INLET MEANS PREVENTING COMMUNICATION BETWEEN SAID CHAMBER AND THE FIRST PNEUMATIC SOURCE IN RESPONSE TO VARIATIONS IN THE FIRST PNEUMATIC SOURCE, SAID LEVER MEANS COMPRISING A PIVOT BRACKET CARRYING SAID VALVE ELEMENT, SPRING MEANS BIASING SAID PIVOT BRACKET, A PIVOT LEVER FOR MOVING SAID BRACKET AGAINST SAID BIASING MEANS, RESILIENT MEANS FOR BIASING SAID PIVOT LEVER, AND MEANS ON SAID PIVOT LEVER ENGAGING THE MOVABLE PORTION OF SAID TEMPERATURE RESPONSIVE MEANS.