Patent ID: 6095188
Filing Date: 2000-08-01
Classification: F16K,Y10S,Y10T

Abstract:
Normally closed, three-way valve structure comprisinga valve housing,said housing having a supply passage for fluid under pressure entering said housing, a control passage, and an exhaust passage,a valve assembly for controlling communication between said supply passage and said control passage and between said control passage and said exhaust passage,said valve assembly comprising a first valve in said supply passage movable between open and closed positions to open and close communication between said supply and control passages,said valve assembly comprising a second valve movable between open and closed positions to open and close communication between said control and exhaust passages,said first valve normally being held in a closed position by the pressure of fluid in said supply passage,control means operative, when activated, to move said second valve to the closed position thereof, anda pintle between said first and second valves,said pintle being shifted in one direction by said second valve, when the latter is moved to the closed position thereof in response to activation of said control means, to move said first valve to the open position thereof against the pressure of fluid in said supply passage,said pintle being shifted in the opposite direction by said first valve when said control means is de-activated, to move said second valve to the open position thereof,said valve assembly further comprising spring means applying force on said first valve in the open position thereof and during an initial portion only of its movement toward the closed position thereof to assist the fluid pressure in said supply passage in causing the initial movement of said first valve toward the closed position thereof,a stop in said supply passage,said spring means comprising a compression coil spring loosely captured between said first valve and said stop,said first valve, when in the closed position thereof, being spaced from said stop a distance which exceeds the length of the coil spring in the uncompressed natural, free-state condition of the latter, whereby said first valve is completely relieved of the force of said spring means when said first valve is in the closed position thereof.