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
Andrzej M Pawlak, Troy, MI (US);
David W Graber, Millington, 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, a mechanically resilient element for generating a mechanical centering force in relation to the relative rotation of the spool and valve body which tends to restore the spool and valve body to a centered condition, and an integral electromagnetic mechanism which variably opposes the mechanical centering force to adjust the level of operator steering input required to produce a given level of power assist. The electromagnetic mechanism comprises an energized coil and a pair of flux conducting elements supported for rotation with the spool and valve body, respectively. The flux conducting elements have interleaved teeth which are magnetically coupled to the coil to define a magnetic circuit having an inter-tooth working air gap which varies with the relative rotation of the spool and valve body.