Patent ID: 8220485

Claim:
A pneumatic pilot valve comprising: a valve body having an inlet, an outlet, and a flow passage extending between the inlet and the outlet; a first valve arranged to control flow through a first part of the flow passage; a second valve arranged to control flow through a second part of the flow passage, the second valve including a tapered valve seat, the tapered valve seat comprising a tapered seating surface opening into a cylindrical seating surface; a thrust pin disposed in the flow passage and having a first part and a tapered second part, the thrust pin including an annular recess adjacent the tapered second part, the thrust pin movable between a first position, a second position, and an intermediate position; a resilient seal sized to fit in the annular recess; the first part of the thrust pin arranged to permit the closing of the first valve in the first position or the intermediate position and arranged to permit the opening of the first valve in the second position; the tapered second part of the thrust pin arranged to permit the opening of the second valve in the first position and arranged to permit the closing of the second valve in the second position; and the annular recess arranged to permit the resilient seal to sealingly engage the cylindrical seating surface to close the second valve when the thrust pin is in the intermediate position or the second position to provide non-simultaneous actuation of the first and second valves thereby defining a pilot valve deadband to eliminate a transition flow through the flow passage in the intermediate position.