Filter having a change indicator
First Claim
1. A filter for filtering particulate contaminants from an air stream, comprising:
- (a) a filter media for filtering the particulate contaminants from the air stream, said filter media having a first major surface and a second major surface for air flow through said filter media from said first major surface to said second major surface;
(b) an air impervious indicator patch having a first major surface and a second major surface, a periphery and a center; and
(c) means adapted to support said indicator patch at a desired location adjacent a portion of one of said first major surface or second major surface of said filter media;
(d) wherein said indicator patch is adapted to impede the air flow through said filter media and divert the air stream so that contaminants are progressively accumulated in said filter media from said periphery towards said center of said air impervious indicator patch as an indication of use of the filter.
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Accused Products
Abstract
Disclosed is a change indicator for a filter for use in a gaseous circulation system, such as a forced air heating and cooling system. The change indicator includes an air impervious patch that is secured to the filter. The portion of the filter media adjacent to the change indicator changes appearance in response to the accumulation of contaminants at a much slower rate than the remainder of the air filter. The accumulation of contaminants progresses inwardly from the region adjacent the periphery of the change indicator towards the region adjacent to the center. Once the appearance of the filter media beneath the change indicator fully changes from periphery to the center, that is an indication that the air filter is in need of cleaning or replacement.
173 Citations
14 Claims
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1. A filter for filtering particulate contaminants from an air stream, comprising:
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(a) a filter media for filtering the particulate contaminants from the air stream, said filter media having a first major surface and a second major surface for air flow through said filter media from said first major surface to said second major surface; (b) an air impervious indicator patch having a first major surface and a second major surface, a periphery and a center; and (c) means adapted to support said indicator patch at a desired location adjacent a portion of one of said first major surface or second major surface of said filter media; (d) wherein said indicator patch is adapted to impede the air flow through said filter media and divert the air stream so that contaminants are progressively accumulated in said filter media from said periphery towards said center of said air impervious indicator patch as an indication of use of the filter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A change indicator for use with a filter having a filter media for filtering particulate matter from a gaseous stream passing through the filter media from a first major surface to a second major surface of the filter media, comprising:
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(a) a gas impervious indicator patch; and (b) means adapted to support said indicator patch at a desired location adjacent to a portion of one of the first major surface or second major surface of the filter media; (c) wherein the flow of the gas through the filter is impeded and diverted adjacent said indicator patch so that contaminants in the gas are progressively accumulated in the filter media from said periphery towards said center of said gas impervious indicator patch. - View Dependent Claims (12, 13)
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14. A filter for filtering particulate contaminants from a gas stream, comprising:
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(a) a filter media for filtering the particulate contaminants from the gas stream, said filter media having a first major surface and a second major surface for gas flow through said filter media from said first major surface to said second major surface; (b) a gas impervious indicator patch having a first major surface and a second major surface, a periphery and a center; and (c) means adapted to support said indicator patch at a desired location adjacent a portion of one of said first major surface or second major surface of said filter media; (d) wherein said indicator patch is adapted to impede the gas flow through said filter media and divert the gas stream so that contaminants are progressively accumulated in said filter media from said periphery towards said center of said gas impervious indicator patch as an indication of use of the filter.
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Specification