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. 25, 2009
Filed:
Feb. 18, 2003
Mark Kowalak, Troy, OH (US);
Kirk Neer, Sidney, OH (US);
Stephen Pasley, Springboro, OH (US);
Crane Pumps & Systems, Inc., Piqua, OH (US);
Abstract
An arrangement () for controlling the liquid level in a basin () by selectively actuating a pump () has an environmentally-sealed enclosure () with an internal volume subject to thermal and pressure effects. A first () and a second () pressure sensing means are positioned in the enclosure and a barrier fluid () fills a balance of the internal volume. The first sensing means () is in a first chamber () of the enclosure () and the second sensing means () is in a second chamber (). The barrier fluid () has a first portion () in the first chamber () and a second portion in the second chamber (). The first pressure sensing means () communicates an 'on/off' signal to the pump (). Diaphragms () in the respective chambers () allow the device to adjust to changes in atmospheric pressures. The barrier fluid () is electrically non-conductive, chemically non-reactive with any materials comprising the pressure sensing means and, preferably, an oil.