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:
Aug. 06, 1996
Filed:
Jan. 05, 1996
Wilbur D Hutchens, Marshalltown, IA (US);
Virgil W Pepper, Marshalltown, IA (US);
Frank E Jensen, Marshalltown, IA (US);
Fisher Controls International, Inc., Clayton, MO (US);
Abstract
A fluid valve graphite packing assembly with graphite packing rings and thin PTFE disc rings surrounding an operating valve member. Softer graphite packing rings on the interior are bounded by progressively harder graphite packing rings. A PTFE disc ring is inserted between the graphite packing rings. The packing is subjected to sufficient packing stress to cause the PTFE disc rings to extrude onto the operating valve member. A laminated packing ring formed of alternating sheets of flexible graphite and PTFE which is die cut to provide a crown shaped cross-section aiding in enabling PTFE extrusion to enhance valve operating member lubrication and sealing.