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:
Oct. 30, 1990
Filed:
Jun. 08, 1989
Ricky R Ruschke, McHenry, IL (US);
Filtertek, Inc., Hebron, IL (US);
Abstract
A center flow check valve of the diaphragm type is inexpensive to manufacture and has reliably great sensitivity in both forward and reverse flow. The valve includes an imperforate diaphragm that is loose, e.g., is not affirmatively held in place by a pin or the like, and the center portion of the diaphragm as well as the periphery move axially in various modes of operation. Various elements help to keep the diaphragm centered. A reverse flow path directs back flow to the center of the downstream surface of the diaphragm. The back flow lifts the diaphragm from support edges about which it flexes during forward flow and seals it against a concave sealing surface. The diaphragm is protected against strong pressure in the forward direction by a flow deflector and against strong back flow pressure by the concave sealing surface. In the absence of forward or backward fluid pressure, the diaphragm assumes a neutral configuration in which it seals against back flow by making line contact with a convex curved surface disposed on the upstream side of the diaphragm.