Patent ID: 7841841

Claim:
A flow prioritizing system, comprising: a pump configured to be driven at a drive speed and operable, upon being driven, to supply fluid at a pump discharge pressure; a regulating valve in fluid communication with the pump to receive a first portion of the fluid supplied therefrom, the regulating valve including a valve body and a valve element, the valve body comprising a first section, a second section, a secondary flow inlet port, a secondary flow outlet port, a reference pressure port, and a control pressure inlet port, the first section having a first cross sectional area and having the secondary flow inlet port and the secondary flow outlet port formed therein, the second section having a second cross sectional area that is greater than the first cross sectional area and having the reference pressure port and the control pressure inlet port formed therein, the secondary flow inlet port in fluid communication with the pump to receive the first portion of the fluid supplied therefrom, the reference pressure port adapted to be coupled to a reference pressure source, the valve element disposed within the valve body and comprising a first spool and a second spool, the first spool coupled to, and fluidly isolated from, the second spool and having a first diameter, the second spool having a second diameter that is greater than the first diameter, the valve element second spool disposed in the second section and dividing the second section into first and second chambers, the first chamber in fluid communication with the control pressure inlet port, the second chamber in fluid communication with the reference pressure port, the valve element movable, in response to priority control fluid pressure at the control pressure inlet port to move between a closed position, in which the secondary flow inlet port is not in fluid communication with the secondary flow outlet port the first portion of the fluid does not flow through the regulating valve, and a plurality of open positions, in which the secondary flow inlet port is in fluid communication with the secondary flow outlet port the first portion of the fluid does flow through the regulating valve; and a flow prioritizing control valve including a pump capacity control pressure inlet port, and a prioritizing control pressure outlet port, the pump capacity control pressure inlet port adapted to receive fluid at a pressure representative of the pump discharge pressure, the prioritizing control pressure outlet port in fluid communication with the regulating valve control pressure inlet port, the flow prioritizing control valve responsive to the pressure at the pump capacity fluid pressure inlet port to selectively supply fluid to the regulating valve control pressure inlet port at a control fluid pressure that moves the regulating valve at least toward the closed position.