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:
Aug. 14, 1990
Filed:
Feb. 05, 1990
Ellsworth S Miller, Rochester Hills, MI (US);
Michael Slavin, Caseville, MI (US);
Ching C Ling, Plymouth, MI (US);
Lectron Products, Inc., Rochester Hills, MI (US);
Abstract
A variable force solenoid valve assembly is provided for use in an automatic transmission controller for controllably reducing a fluid inlet pressure to a desired outlet control pressure. The invention includes a variable force solenoid assembly secured to a valve body assembly. The valve body assembly includes a spool valve having three radially extending lands which translates within a valve body central bore in response to movement of an armature assembly provided in the solenoid assembly. Movement of the spool valve generates first and second flow restriction for controllably regulating the reduction of inlet pressure to control pressure. In addition, various improvements in spool valve design are described including a design which provides positive damping of the spool valve so as to attenuate 'self-excited' oscillation thereof.