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:
Sep. 08, 1987
Filed:
Jan. 28, 1987
Neil H Akkerman, Houston, TX (US);
Gonzalo Vazquez, Houston, TX (US);
AVA International Corporation, Houston, TX (US);
Abstract
There are disclosed several embodiments of a fail safe gate valve and actuator having means for yieldably urging the gate from one position to which it is moved under one or more controlled conditions to its other position upon failure of one such condition, means including a handwheel mounted on the actuator for moving the gate to its one position, and means automatically responsive to a control signal for rendering the handwheel inoperative to move the gate to its one position upon reestablishment of said one controlled condition. In certain embodiments, the control signal is automatically responsive to the reestablishment of said one controlled condition; and, in another embodiment, it is automatically responsive to the failure of said one controlled condition. The controlled conditions are disclosed as being one or both of a predetermined fluid pressure condition, and or a predetermined environmental temperature condition.