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:
May. 20, 2008
Filed:
Dec. 09, 2005
Joseph Gerard Burgart, Des Moines, IA (US);
Mark David Evans, Grovetown, GA (US);
Joseph Gerard Burgart, Des Moines, IA (US);
Mark David Evans, Grovetown, GA (US);
Deere & Company, Moline, IL (US);
Abstract
A control apparatus is provided for a hydrostatic transmission to simulate a gear drive on a tractor. The hydrostatic transmission has a swashplate that is angularly movable to a plurality of positions, and a proportional valve that provides a control pressure to a servo piston to control the hydrostatic transmission swashplate position. A transmission control lever may be moved to a plurality of positions, each position providing a different voltage signal to a microcontroller. The microcontroller receives and converts a voltage signal to a coil current to actuate the proportional valve.