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:
May. 26, 1998
Filed:
Feb. 21, 1996
Edward H Phillips, Troy, MI (US);
Techco Corporation, Southfield, MI (US);
Abstract
Methods and apparatus for improving control of pressurized fluid flow through bootstrap power steering systems are disclosed. In particular, the methods include differentially measuring control pressure across internal flow control orifices as directly as possible. Differential control pressure measurements are made between Kelvin supply, or return, pressure values and a control pressure port of a control valve. In addition, methods and apparatus for improved speed sensitive control of steering assist and/or driver selectable steering effort are also disclosed. One of the methods comprises an extension of the method of differentially measuring control pressure across the internal flow control orifices wherein a range of control pressures are enabled. In addition, a method of improving low speed tactile steering feel wherein an electronically variable orifice is activated in order to provide additional fluid flow thereby increasing 'on-center' hydraulic pressure gain is disclosed.