The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 09, 2010
Filed:
Dec. 03, 2007
Edward C. Messerlie, Platteville, WI (US);
Neil V. Harber, Holy Cross, IA (US);
Joshua D. Graeve, Peosta, IA (US);
Edward C. Messerlie, Platteville, WI (US);
Neil V. Harber, Holy Cross, IA (US);
Joshua D. Graeve, Peosta, IA (US);
Deere & Company, Moline, IL (US);
Abstract
A hydraulic control system in which a pump for pressurized hydraulic fluid connects with a valve assembly having a valve element displaceable in a chamber to selectively direct fluid to a load driven by the hydraulic system. Surfaces on the end faces of the valve element are exposed to hydraulic pressure from a controller via electro-hydraulic solenoid valves. The surfaces of the valve element adjacent the end faces are undercut to establish a leakage flow path and the solenoid valves are selectively actuated to pressurize the end faces to a level below normal actuation of the valve element but high enough to cause fluid to return to a drain and thus increase the temperature of the hydraulic fluid in the system.