Patent ID: 6769249
Filing Date: 2004-08-03
Classification: B62D,Y10T

Abstract:
A fluid controller operable to control the flow of fluid from a source of pressurized fluid to a fluid pressure operated device having an inlet and an outlet and defining a fluid leakage path therebetween; said fluid controller being of the type including a housing defining an inlet port for connection to the source of pressurized fluid, a return port for connection to a system reservoir, and a control port for connection to said inlet of said fluid pressure operated device, valving disposed in said housing and defining a neutral position, a normal operating position and a maximum displacement position, said housing and said valving cooperating to define a main fluid path providing fluid communication between said inlet port and said control port when said valving is in said normal operating position; fluid actuated means for imparting follow-up movement to said valving, tending to return said valving from said normal operating position toward said neutral position, said follow-up movement being proportional to the volume of fluid flow through said main fluid path, said main fluid path including a first variable flow control orifice, having a minimum flow area when said valving is in said neutral position, and an increasing flow area as said valving is displaced through said normal operating position toward said maximum displacement position; characterized by:(a) said valving defining a fluid bleed passage having an upstream portion in fluid communication with said main fluid path at a location upstream of said first variable flow control orifice, and a downstream portion in fluid communication with said main fluid path downstream of said fluid actuated means; and (b) said fluid bleed passage including a variable bleed orifice having a substantially zero flow area when said valving is in said neutral position and in said normal operating position, said variable bleed orifice beginning to open as said valving approaches said maximum displacement position.