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:
Feb. 12, 2002
Filed:
Aug. 23, 2000
David Joseph Easton, Cedar Falls, IA (US);
Deere & Company, Moline, IL (US);
Abstract
A tracked vehicle has an electrohydraulic drive/steering system having an engine driven variable displacement hydraulic steering pump which drives a hydraulic steering motor which is coupled to a differential track drive mechanism via a transmission with multiple gear ratios. A steering wheel is coupled to a variable friction device which produces a variable friction force which resists rotation of the steering wheel. A control system is responsive to a position of the steering wheel and controls the steering pump displacement and controls the friction device. The control system sets the variable friction device to its high friction level when a limit of the steering pump displacement is reached when the transmission is in a higher one of its gear ratios.