Patent ID: 7866151

Claim:
In a hydraulic system comprising a source ( 11 ) of pressurized fluid, a priority load circuit ( 17 ) receiving pressurized fluid from said source ( 11 ) and providing a priority load signal ( 19 ), and an auxiliary load circuit ( 25 ) receiving pressurized fluid from said source ( 11 ); said auxiliary load circuit ( 25 ) including a pilot-operated main control valve ( 27 ) biased in a first direction by a first pilot signal ( 33 ), in opposition to the force of a first biasing spring ( 37 ), said first pilot signal ( 33 ) being provided by a first pilot valve ( 35 ) having an inlet ( 35 I) in fluid communication with a source ( 45 ) of pilot pressure; said hydraulic system being characterized by: (a) an anti-saturation valve assembly ( 51 ) having an inlet ( 55 ) in fluid communication with said source ( 45 ) of pilot pressure, and an outlet ( 57 ) in fluid communication with said inlet ( 35 I) of said first pilot valve ( 35 ); (b) said anti-saturation valve assembly ( 51 ) including a pressure reducing valve ( 63 ) normally biased toward a first position ( FIG. 5 ) communicating substantially said full pilot pressure from said inlet ( 55 ) of said anti-saturation valve assembly ( 51 ) to said inlet ( 35 I) of said first pilot valve ( 35 ); (c) said anti-saturation valve assembly ( 51 ) further including means ( 61 ) for sensing the pressure difference between said source ( 11 ) of pressurized fluid, and said priority load signal ( 19 ); and (d) means ( 83 , 79 ) operable to convert said pressure difference into a biasing force, when said pressure difference begins to decrease, said biasing force biasing said pressure reducing valve ( 63 ) toward a second position communicating only a reduced pilot pressure to said inlet ( 35 I) of said first pilot valve ( 35 ).