Patent ID: 6431209
Filing Date: 2002-08-13
Classification: B29C,C03B,F15B,F16K,Y10S,Y10T

Abstract:
A selector fluid control valve for selectively supplying at least two different working fluid pressures to a fluid-actuated device, said selector fluid control valve comprising: a high-pressure inlet in fluid communication with a source of working fluid at a relatively high pressure; a low-pressure inlet in fluid communication with a source of working fluid at a relatively low pressure; and a load fluid outlet passageway interconnected in fluid communication with the fluid-actuated device, said selector fluid control valve further having a normally closed high-pressure valve mechanism in fluid communication between said high-pressure inlet and said load fluid outlet passageway to selectively allow high-pressure fluid flow from said high-pressure inlet to said load fluid outlet passageway, and a normally open low-pressure valve mechanism in fluid communication between said low-pressure inlet and said load fluid outlet passageway to selectively allow low-pressure fluid flow from said low-pressure inlet to said load fluid outlet passageway, said selector fluid control valve further having a pilot actuator selectively operable to force said normally closed high-pressure valve mechanism into an open position and allow said high-pressure fluid flow from said high-pressure inlet to said load fluid outlet passageway, said high-pressure fluid in said load fluid outlet passageway forcing said normally open low-pressure valve mechanism into a closed position to prevent reverse fluid flow between said high-pressure inlet and said low-pressure inlet, wherein at least one of said high-pressure and low-pressure valve mechanisms includes a generally frusto-conical valve seat located in a valve fluid passageway in fluid communication with said load fluid outlet passageway, said valve seat having a smaller-diameter end and a larger-diameter end, and a generally spherical ball-poppet being selectively movable between said respective closed and open positions into and out of substantially ball-poppet line-contact for sealing with said smaller-diameter end of said supply valve seat, said generally spherical ball-poppet having a chord dimension at said line-contact with said smaller-diameter end of said valve seat that is smaller than said larger-diameter end of said valve seat, said generally frusto-conical valve seat having a seat angle relative to the centerline of said valve seat that is greater than an angle formed by the centerline of said valve seat and a line tangent to said spherical ball-poppet at said ball-poppet line-contact when said ball-poppet is in said closed position, an annular space formed between said valve seat and said spherical ball-poppet defining a restricted flow area adjacent said ball-poppet line-contact between said spherical ball-poppet and said smaller-diameter end of said valve seat as said spherical ball-poppet initially moves out of said line-contact to its open position and as said working fluid initially flows past said ball-poppet, any sonic flow erosion caused by said initial working fluid flow thereby being shifted substantially immediately to an upstream flow area that is adjacent said ball-poppet line contact and that is not sealingly contacted by said spherical ball-poppet thus substantially minimizing sonic damage to said smaller-diameter end of said valve seat.