Patent ID: 6173730
Filing Date: 2001-01-16
Classification: B60T,Y10T

Abstract:
A valve for use in a brake system through which a source of fluid charges an accumulator to a desired fluid pressure level and through which fluid pressure present in a conduit is communicated to a reservoir in the absence of the flow of fluid from said source, said valve comprising:a housing having a first bore therein with an entrance port connected to said source of fluid, an exit port connected to said accumulator and an exhaust port connected to said reservoir;a sleeve located in said first bore, said sleeve having a second bore that extends from a first end to a second end, said second bore having a central diameter section separated from a first end diameter section by a first shoulder and from a second end diameter section by a second shoulder;a first ball located in said first end diameter section,a first spring for urging said first ball toward said first shoulder;a second ball located in said second diameter section and retained in said second diameter section by a flange on said second end of said sleeve;linkage located in said central diameter section having a first end and a second end, said first end engaging said first ball and said second end engaging said second ball; anda second spring located in said first bore for urging said sleeve toward said entrance port to allow said first spring to seat said first ball on said first shoulder and prevent communication between said central diameter section and said entrance port while permitting communication free communication between said between said exit port and said exhaust port to allow fluid in said conduit to flow to said reservoir, said second spring being compressed by a charging force developed by pressurized fluid from said source acting on said first end of said sleeve, said charging force initially moving said sleeve toward said exit port to bring said second ball into engagement with an exhaust seat surrounding said exhaust port to interrupt communication from said first bore to said reservoir and with further movement compress said first spring to allow said first ball to move off an communication seat defined by said first shoulder and allow fluid to flow to said accumulator by way of said second bore and exhaust port.