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, 1997
Filed:
Feb. 12, 1996
John J Wordin, Shelley, ID (US);
Other;
Abstract
A retrofit valve stem seal assembly, which can be retrofitted to existing quarter-turn valves already in service, is provided. The retrofit valve stem seal assembly is added to the valve stem by inserting a valve stem adaptor onto the valve stem and firmly attaching the adaptor to the valve stem. The inner surface of the valve stem adaptor fits on the valve stem. To prevent leaks between the valve stem adaptor and the valve stem, 'O' rings are installed in the valve stem adaptor to bear against the valve stem. A rotatable valve stem adaptor includes a sliding tractrix surface for sliding contact with a stem packing. The stem packing includes a complementary tractrix surface for contacting the sliding tractrix surface on the valve stem. Wear between the contacting surfaces is uniform at all points of contact between the sliding tractrix surface and the complementary tractrix surface, creating and maintaining a dynamic seal. The stem packing also includes an outer cylindrical surface for contacting a complementary cylindrical surface of the valve bonnet creating and maintaining a static seal.