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:
May. 22, 2001
Filed:
Sep. 23, 1996
Edward McKiernan, Big Prairie, OH (US);
James A. Sigler, Perrysville, OH (US);
William J. Friedman, Wooster, OH (US);
Sealand Technology, Inc., Big Prairie, OH (US);
Abstract
A plastic sewage holding tank in a boat, associated with a toilet, includes a vent check valve for providing vacuum relief. By mounting the vent check valve in the top of the tank, when the tank is being emptied by rapid pumpout implosion or other damage to the tank is prevented. The vent check valve may include a valve body with an interior surface mounting a quad sealing ring, with a valve element guided for reciprocal movement between a sealing position where an axially elongated substantially cylindrical peripheral surface of the valve element engages the quad ring, to an open position where the valve element is moved against spring bias away from the valve body. A spider, with a collar for guiding a shaft portion of the valve element, may mount a coil spring to provide a biasing action.