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. 05, 1980
Filed:
Jul. 11, 1978
Erich Jablonsky, Boebingen, DE;
Zahnradfabrik Friedrichshafen AG, Friedrichshafen, DE;
Abstract
A dual hydraulic system comprising two independent power steering hydraulic circuits is provided wherein a first hydraulic circuit is used primarily for normal steering and a second hydraulic circuit is used where increased steering power is needed as in rough terrain driving or in parking a vehicle. The arrangement provides for each circuit carrying about half the increased load. Respective valve mechanisms under operator control via a steering wheel controls pressure and exhaust of the double acting power cylinders of the respective circuits. Actuation of the two valve mechanisms is effected in a sequential order so that ordinarily the first hydraulic circuit is operative, followed by the operation of the second hydraulic circuit responsive to increase in steering load as would be occasioned in cross country rough terrain driving or in a vehicle parking situation.