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:
Jul. 28, 1987
Filed:
Jul. 18, 1986
William S Shelton, Houston, TX (US);
Joy Manufacturing Company, Pittsburgh, PA (US);
Abstract
A rising stem expanding gate valve including an improved metal-to-metal stem backseat seal assembly. An axially slidable seal ring is press fit onto the valve stem and is adapted to seal against a counterbored bonnet seat portion to provide a secondary metal-to-metal stem to bonnet seal. The seal ring is allowed to move a limited axial distance on the valve stem such that upon upward axial movement of the valve stem. The seal ring is repositioned in an axially downward direction about the valve stem and, consequently, is firmly sealed against the bonnet seat portion. Upon subsequent downward movement of the valve stem, the seal ring is repositioned in an axial upward direction about the valve stem such that the seal ring is in its original position about the valve by a repositioning means.