Filter restriction indicator
First Claim
1. An indicator device, for indicating when a pressure difference has been exceeded, comprising:
- (i) a casing bounding an internal chamber and having a first port and a second port communicating with said chamber, said casing including an at least translucent portion,(ii) a resiliently-deformable diaphragm positioned in said chamber and secured to said casing in fluid-tight manner, said diaphragm having an aperture bounded by an internal margin,(iii) a member disposed in said casing and movable towards and through said aperture, said member including a margin-contacting portion in sealing relation to said margin whereby said diaphragm and said movable member together serve to divide said chamber into a first chamber portion communicating with said first port and a second chamber portion communicating with said second port, said margin-contacting portion being shaped to progressively pass through said aperture responsive to a progressively increasing pressure difference between said first port and said second port, said margin-contacting portion including retaining means which, upon movement through and beyond said margin as a result of exceeding of a predetermined pressure differential, cooperates with said margin to retain the movable member in a retained condition and prevent return movement thereof, said movable member in said retained condition being positioned within said at least translucent portion such that its retained condition can be observed.
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Accused Products
Abstract
An indicator device for indicating when a prechosen pressure difference has been exceeded comprises a casing having two ports separated by a resilient diaphragm with an aperture therein, and a movable member urged into sealing relation with said aperture so as to prevent leakage therethrough, the configuration of the member and the aperture being selected so that, in use, the application of a prechosen pressure differential between said ports will cause the member to partly pass through the aperture to a position whereat it is retained by the diaphragm, said member being provided with means for indicating that it has been so retained.
51 Citations
7 Claims
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1. An indicator device, for indicating when a pressure difference has been exceeded, comprising:
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(i) a casing bounding an internal chamber and having a first port and a second port communicating with said chamber, said casing including an at least translucent portion, (ii) a resiliently-deformable diaphragm positioned in said chamber and secured to said casing in fluid-tight manner, said diaphragm having an aperture bounded by an internal margin, (iii) a member disposed in said casing and movable towards and through said aperture, said member including a margin-contacting portion in sealing relation to said margin whereby said diaphragm and said movable member together serve to divide said chamber into a first chamber portion communicating with said first port and a second chamber portion communicating with said second port, said margin-contacting portion being shaped to progressively pass through said aperture responsive to a progressively increasing pressure difference between said first port and said second port, said margin-contacting portion including retaining means which, upon movement through and beyond said margin as a result of exceeding of a predetermined pressure differential, cooperates with said margin to retain the movable member in a retained condition and prevent return movement thereof, said movable member in said retained condition being positioned within said at least translucent portion such that its retained condition can be observed. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification