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. 16, 1993
Filed:
Nov. 02, 1992
Jon R Patton, Coffeyville, KS (US);
Robert W Harris, Coffeyville, KS (US);
Deere & Company, Moline, IL (US);
Abstract
A transmission control system includes a plurality of hydraulic pressure operated control elements for engaging a gear of the transmission in response to actuation of a shift control lever having neutral and non-neutral positions, a plurality of control valves for controlling pressurization of the control elements and a pump for supplying pressurized fluid to the control valves. An engagement override system includes a switch which is coupled to the shift lever and which energizes a solenoid when the shift lever is in its neutral position and de-energizes the solenoid when the shift lever is in its non-neutral position. In a preferred embodiment, an engagement override valve includes a pilot operated valve which controls communication between the pump, a reservoir and the pressure operated control elements. The solenoid controls the pilot operated valve. The valve also includes a pilot chamber which is pressurized to move the valve to and hold the valve in a position wherein the pump is communicated with the pressure operated control elements.