Patent ID: 6330798
Filing Date: 2001-12-18
Classification: F15B

Abstract:
A hydraulic valve assembly comprising:a main control valve for connection to a first hydraulic operator and having a main valve poppet slidably located within a first bore to control flow of fluid between a first inlet and a first outlet and defining a first control chamber on a side of the main valve poppet that is remote from the first outlet, and a selectively moveable pilot poppet engaging and controlling movement of the main valve poppet; anda shadow valve for connection to a second hydraulic operator and having a shadow poppet slidably located within a second bore to control flow of fluid between a second inlet and a second outlet, a second control chamber formed on a side of the shadow poppet that is remote from the second outlet and the second control chamber being in fluid communication with the first control chamber;wherein movement of the pilot poppet affects pressure in the first control chamber and in the second control chamber thus producing corresponding movement of the shadow poppet and the main valve poppet.