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:
Dec. 15, 1998
Filed:
Feb. 24, 1995
Charles Henry Berry, III, Cedar Falls, IA (US);
Engineered Products Co., Waterloo, IA (US);
Abstract
An air restriction indicating device for measuring very low ranges of filter restriction (e.g., on the order of 0.0 to 1.5 inches of H.sub.2 O or 0.0 to 0.54 psi) in a micronfilter used in vehicular heating/ventilation/air conditioning (HVAC) systems. The indicating device includes a housing that is separated into two sub-chambers by a flexible diaphragm. A indicating member is carried by the diaphragm so that the diaphragm and the indicating member move, within the housing, responsively to changes in the pressure of the air flowing in the HVAC system caused by restrictions in or clogging of the micronfilter. To facilitate reading, the indicating device also includes structure that progressively locks the diaphragm and indicating member in position.