Filter change indicator
First Claim
1. An air filter monitoring system for indicating when to clean or replace a flexible air filter, the air filter monitoring system comprising:
- (a) a pleated flat-panel air filter having a peripheral frame and an interior filtering region;
(b) a fixed support structure for receiving the air filter and maintaining the perimeter of the filter frame in a generally fixed position while allowing the interior filtering region to flex in response to air flow through the filter; and
(c) a filter change indicator having a predetermined bias force, the filter change indicator including a housing, a position sensitive electrical switch arranged in the housing, a filter engagement member arranged to actuate the switch, and a biasing member arranged to resist a force applied to the filter engagement member by the interior filtering region upon flexing of the filter, wherein as the interior filtering region flexes in response to air flow through the filter, the interior filtering region exerts a force on the filter engagement member that increases with the degree of clogging of the filter and, when the predetermined bias force is reached, the filter engagement member triggers the switch to notify a user to clean or replace the filter.
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Accused Products
Abstract
An air filter monitoring system for indicating when to clean or replace a flexible air filter includes an air filter having a peripheral frame and an interior filtering region, a fixed support structure for receiving the air filter and maintaining the perimeter of the filter frame in a generally fixed position while allowing the interior filtering region to flex in response to air flow through the filter, and a filter change indicator having a predetermined bias force. The filter change indicator is arranged to contact the interior filtering region of the filter, wherein when the predetermined bias force is reached, the filter change indicator is activated to notify a user to clean or replace the filter.
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Citations
13 Claims
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1. An air filter monitoring system for indicating when to clean or replace a flexible air filter, the air filter monitoring system comprising:
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(a) a pleated flat-panel air filter having a peripheral frame and an interior filtering region; (b) a fixed support structure for receiving the air filter and maintaining the perimeter of the filter frame in a generally fixed position while allowing the interior filtering region to flex in response to air flow through the filter; and (c) a filter change indicator having a predetermined bias force, the filter change indicator including a housing, a position sensitive electrical switch arranged in the housing, a filter engagement member arranged to actuate the switch, and a biasing member arranged to resist a force applied to the filter engagement member by the interior filtering region upon flexing of the filter, wherein as the interior filtering region flexes in response to air flow through the filter, the interior filtering region exerts a force on the filter engagement member that increases with the degree of clogging of the filter and, when the predetermined bias force is reached, the filter engagement member triggers the switch to notify a user to clean or replace the filter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A portable room air purifying device, comprising:
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(a) a chassis including an air filtering chamber having an air inlet opening and an air discharge opening; (b) a pleated flat-panel filter mounted in the filtering chamber between the inlet and the discharge openings, the filter including a peripheral frame mounted in a fixed position relative to the chassis and including a flexible interior filtering region comprising fibrous filter media that bows outwardly with respect to the frame when air flows through the filter; and (c) a filter change indicator arranged at a predetermined stationary location relative to the chassis, the filter change indicator having a predetermined bias force, the filter change indicator including a housing, a position sensitive electrical switch arranged in the housing, a filter engagement member arranged to actuate the switch, and a biasing member arranged to resist a force applied to the filter engagement member by the interior filtering region upon flexing of the filter, wherein as the interior filtering region flexes in response to air flow through the filter, the interior filtering region exerts a force on the filter engagement member that increases with the degree of clogging of the filter and, when the predetermined bias force is reached, the filter engagement member triggers the switch to notify a user to clean or replace the filter.
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Specification