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:
Nov. 03, 1992
Filed:
Jun. 20, 1991
Applicant:
Inventor:
Nam V Le, Lewisville, TX (US);
Assignee:
Otis Engineering Corporation, Dallas, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ; F16K / ;
U.S. Cl.
CPC ...
166325 ; 137515 ; 137527 ;
Abstract
A flapper valve assembly when closed permits flow through in one direction and prevents flow in the opposite direction. When open, two way flow may occur and the flapper valve member is biased toward closed position, to sealingly engage an annular seat, by one or more springs in the wall of the flapper valve housing. This structure provides a greater closing force applied to the flapper valve through a tension member connected to the flapper valve hinge. Three forms of tension members are disclosed.