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. 14, 1993
Filed:
Oct. 04, 1991
Douglas G Calvin, Missouri City, TX (US);
Edward G Holtgraver, Spring, TX (US);
Keystone International Holdings Corp., Houston, TX (US);
Abstract
A sealing assembly, usable with a valve or the like, having a movable shaft within a main housing and controlling a product under a first pressure. A cartridge housing forms a continuation of the main housing. An extension of the shaft extends through the cartridge housing and forms an annulus therewith. Spaced first and second annular seals movably seal the annulus between the shaft extension and the cartridge housing, forming a central sealing chamber. An injector introduces sealing medium into the central sealing chamber under a pressure higher than the product pressure. An accumulator receives excess sealing medium from the central sealing chamber, and can also be associated with monitoring means. Additional annular seals may form additional chambers spaced along the shaft, and these chambers may likewise be used for injection of sealing media and/or monitoring and/or leak detection.