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:
Jul. 02, 1991
Filed:
Jun. 04, 1990
Applicant:
Inventor:
Michael D McNeely, Katy, TX (US);
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G05D / ;
U.S. Cl.
CPC ...
137488 ; 1376275 ; 13759618 ;
Abstract
A pilot valve (40) for a control valve (14) has a separate auxiliary source of high pressure fluid (106) for the operation of the pilot valve (40). The dome chamber (36) of the control valve (14), the inlet fluid chamber (72), and the intermediate fluid chamber (104) are exposed only to the auxiliary source of fluid (106). Thus, process fluid from the sensing line (62) does not contaminate the spool valve (76) or the dome chamber (36).