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:
Dec. 12, 1989
Filed:
Dec. 22, 1988
David W Graber, Millington, MI (US);
Andrzej M Pawlak, Troy, MI (US);
Jeffery A Zuraski, Saginaw, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A hydraulic power steering system having conventional relatively rotatable spool and valve body elements for flow regulation, and an integral electromagnetic mechanism which effectively varies the centering force between the spool and valve body to adjust the level of steering assist provided for a given operator steering input. The electromagnetic mechanism comprises a rotary multipole permanent magnet supported for rotation with one of the spool and valve body elements, a rotary flux conducting element supported for rotation with the other of the spool and valve body elements, and a stationary exciting coil magnetically coupled thereto. The exciting coil is energized so as to produce a variable centering force between the spool and valve body with vehicle speed, which produces a corresponding variation in the driver steering effort.