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:
Feb. 17, 1987
Filed:
May. 29, 1985
Applicant:
Inventors:
Michael A Karr, Jr, Houston, TX (US);
John M Zwiegel, Houston, TX (US);
Assignee:
Gray Tool Company, Houston, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16K / ; F16K / ;
U.S. Cl.
CPC ...
251 636 ; 251337 ;
Abstract
A fail-safe valve actuator includes a hydraulic piston (17) and cylinder (15) for driving the valve stem (9) and gate member (35) of a gate valve into a first flow control state responsive to sufficient pressure delivered by a fluid or gas supply line (92). Upon failure or other loss of sufficient control line pressure, a volute spring (7) drives the cylinder (15), and hence the stem (9) and gate member (35), axially outward resulting in the valve being moved into a second flow control state.