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:
Apr. 04, 1989
Filed:
Feb. 16, 1988
Applicant:
Inventor:
David C Winter, Johnston, IA (US);
Assignee:
Deere & Company, Moline, IL (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
A01B / ;
U.S. Cl.
CPC ...
172328 ; 172445 ; 172448 ;
Abstract
An improved hydraulic circuit for raising and lowering a three-point hitch-mounted implement having a lift assist assembly and for selectively lowering the lower draft links of the three-point hitch to transfer implement weight to the rear wheels of the tractor without affecting the normal operation of the tractor operator control valve. A shuttle valve connects the rockshaft control valve, which otherwise would be disabled, to the rockshaft cylinder which controls the lower draft links. The ball-check valve also connects the rockshaft cylinder to the operator control valve while isolating the rockshaft control valve from the operator control valve.