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. 03, 2002
Filed:
Dec. 28, 2000
Douglas H. Powell, Sacramento, CA (US);
Hunter Innovations, Inc., Sacramento, CA (US);
Abstract
A check valve apparatus, usable in a double check valve backflow preventer apparatus, comprising a valve seat, a clapper pivotally coupled to the valve seat, a seal positioned to sealingly engage the clapper and valve seat when the clapper is closed against the seat, and a closure mechanism. The closure mechanism includes a first linkage element pivotally associated with the valve seat at a first pivot point located upstream from the seal, a second linkage element which is pivotally coupled to the first linkage element at a second pivot point, and which is pivotally associated with the clapper at a third pivot point, and a bias element associated with at least one of the linkage elements and configured to exert a closure force on the clapper.