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:
Jul. 24, 2012
Filed:
May. 22, 2009
Neal A. Rakow, Woodbury, MN (US);
Thomas W. Holmquist-brown, St. Paul, MN (US);
Richard J. Poirier, White Bear Lake, MN (US);
Neal A. Rakow, Woodbury, MN (US);
Thomas W. Holmquist-Brown, St. Paul, MN (US);
Richard J. Poirier, White Bear Lake, MN (US);
3M Innovative Properties Company, St. Paul, MN (US);
Abstract
A filter cartridgethat includes a filter material, an end-of-service-life-indicator (ESLI), a housing, a cover, and a window. The filter materialhas first and second major surfacesand is disposed in the housing such that the second major surfaceof the filter material is located downstream to the first major surface. The housing has a sidewallthrough which the ESLIcan be seen. The coveris secured to the housingand has an opaque extensionthat masks at least a portion of the housing sidewall. The windowis positioned on the extensionat a registration position where the ESLIcan be seen through the windowsuch that a change in a certain color of the ESLIindicates that the cartridgeneeds to be replaced. The use of the cartridge cover to provide the ESLI registration position allows the filter cartridges to be mass assembled without risk of error in achieving proper window registration.