Patent Number: 6,305,419

Title: Variable pilot pressure control for pilot valves

Abstract: A hydraulically operated industrial machine has hydraulic work components such as a boom, bucket or the like, and also uses hydraulic motors for propelling the machine. The motors and cylinders are controlled by pilot pressure valves to provide pressure to pilot operated valves. A pressure reducing valve is utilized for providing hydraulic fluid at a pilot pressure to the pilot valves. The reducing valve regulates the pilot pressure as a function of one or more parameters indicating the consumption of hydraulic power in the system, such as drive engine speed, or other signals including oil temperature, throttle position, and, if desired, feedback signals from the system.

Inventors: Krieger; Daniel J. (Bismarck, ND), Wetzel; Michael D. (Bismarck, ND)

Assignee: Clark Equipment Company

International Classification: E02F 9/22 (20060101); E02F 9/20 (20060101); F15B 11/00 (20060101); F15B 11/16 (20060101); F15B 21/00 (20060101); F15B 21/04 (20060101); F15B 013/00 ()

Expiration Date: 10/23/2018