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. 11, 1986
Filed:
Feb. 26, 1985
Applicant:
Inventor:
Michael A Karr, Jr, Houston, TX (US);
Assignee:
Gray Tool Company, Houston, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16K / ;
U.S. Cl.
CPC ...
251 14 ; 251327 ; 1375563 ; 74625 ; 7442 / ; 192 95 ;
Abstract
An actuator for moving the stem (9) of a gate valve or the like is provided with hydraulic means (15,17) for driving the stem (9) axially inward and a volute spring (7) for returning the stem axially outward upon loss or other removal of the control hydraulic pressure. A ball screw (49) and ball nut (54) assembly rotatable by a disengageable drive shaft (63) is operable to manually drive the stem (9) inward during periods of insufficient control pressure.