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:
Jan. 10, 1989
Filed:
Mar. 15, 1988
Applicant:
Inventor:
Jay K Sofianek, Livonia, NY (US);
Assignee:
General Motors Corporation, Detroit, MI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16K / ;
U.S. Cl.
CPC ...
25112915 ; 25112921 ; 251368 ;
Abstract
The armature and active seat of an electromagnetic PWM valve are selectively case hardened at their contacting surfaces to a case depth of approximately 0.50 mm. The hardened areas provide hard contacting surfaces for superior durability, and moreover, create an effective air gap between the armature and the active seat to substantially prevent residual magnetism therebetween. The remaining surfaces of the armature and seat assembly are not hardened, and serve as a low reluctance magnetic flux path around the hardened areas.