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. 10, 1991
Filed:
Oct. 09, 1990
Andrzej M Pawlak, Troy, MI (US);
David W Graber, Millington, 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 to a centered condition, and an integral electromagnetic mechanism which variably assists 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 are radially spaced annular elements with opposed teeth, which elements are magnetically coupled to the coil to define a magnetic circuit having an intertooth working air gap which varies the magnetic reluctance of the circuit with the relative rotation of the spool and valve body such that the teeth are aligned and the reluctance minimized when the spool and valve body are centered.