US5325892A
Expired / Lapsed
US
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Unidirectional fluid valve
Assignee: 3M Innovative Properties Co
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Filing: 1992-11-25
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Granted: 1994-07-05
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Expires: 2012-11-25
Abstract
Abstract An exhalation valve 14 for a filtering face mask 10 has a flexible flap 24 that makes contact with a curved seal ridge 30 of a valve seat 26 when the valve 14 is in the closed position. The curvature of the seal ridge 30 corresponds to a deformation curve exhibited by the flexible flap 24 when secured as a cantilever at one end and exposed at its free portion to a uniform force and/or a force of at least the weight of the free portion of the flexible flap. A seal ridge curvature corresponding to a flexible flap exposed to uniform force allows the flexible flap 24 to exert a generally uniform pressure on the seal ridge to provide a good seal. A seal ridge curvature corresponding to a flexible flap exposed to a force of at least the weight of the flap's free portion allows the flexible flap 24 to be held in an abutting relationship to the seal ridge 30 under any static orientation by a minimum amount of force, thereby providing a face mask 10 with an extraordinary low pressure drop during an exhalation.
Inventors
- 👤 Daniel A. Japuntich
- 👤 Vaughn B. Grannis
- 👤 Harold J. Seppala
- 👤 Anthony B. Ferguson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:06
CPC Classifications
A; A62; A62B; A62B18/00; A62B18/08; A62B18/10; A62B18/02; A62B18/025; A62B18/084; A62B23/00; A62B23/02; A62B23/025; F; F16; F16K; F16K15/00; F16K15/14; F16K15/16; Y; Y10; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0402; Y10T137/0491; Y10T137/7722; Y10T137/7837; Y10T137/7879; Y10T137/7888; Y10T137/7891
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
173 words
A unidirectional fluid valve that comprises: a flexible flap having a first portion and a second portion, the first portion being attached to a valve seat, the valve seat having an orifice and a seal ridge that has a concave curvature when viewed from a side elevation, the flexible flap making contact with the concave curvature of the seal ridge when a fluid is not passing through the orifice, the second portion of the flexible flap being free to be lifted from the seal ridge when a fluid is passing through the orifice, wherein the concave curvature of the seal ridge corresponds to a deformation curve exhibited by the second portion of the flexible flap when exposed to (i) a uniform force that acts along the length of the deformation curve normal thereto, (ii) a force acting in the direction of gravity having a magnitude equal to a mass of the second portion of the flexible flap multiplied by at least one gravitational unit of acceleration, or a combination of (i) and (ii).
Claim 2
Dependent Claim
173 words
A unidirectional fluid valve that comprises: a flexible flap having a first portion and a second portion, the first portion being attached to a valve seat, the valve seat having an orifice and a seal ridge that has a concave curvature when viewed from a side elevation, the flexible flap making contact with the concave curvature of the seal ridge when a fluid is not passing through the orifice, the second portion of the flexible flap being free to be lifted from the seal ridge when a fluid is passing through the orifice, wherein the concave curvature of the seal ridge corresponds to a deformation curve exhibited by the second portion of the flexible flap when exposed to (i) a uniform force that acts along the length of the deformation curve normal thereto, (ii) a force acting in the direction of gravity having a magnitude equal to a mass of the second portion of the flexible flap multiplied by at least one gravitational unit of acceleration, or a combination of (i) and (ii).
Claim 3
Dependent Claim
51 words
The unidirectional fluid valve of claim 2, wherein the concave curvature corresponds to a deformation curve exhibited by the flexible flap when exposed to a uniform force that is not less than the mass of the second portion of the flexible flap multiplied by at least one gravitational unit of acceleration.
Claim 4
Dependent Claim
49 words
The unidirectional fluid valve of claim 2, wherein the concave curvature corresponds to a deformation curve exhibited by the flexible flap when exposed to a uniform force in the range of the mass of the second portion of the flexible flap multiplied by 1.1 to 1.5 g of acceleration.
Claim 5
Dependent Claim
51 words
The unidirectional fluid valve of claim 1, wherein the flexible flap has a stress relaxation sufficient to keep the second portion of the flexible flap in leak-free contact to the seal ridge under any static orientation for twenty-four hours at 70° C. when a fluid is not passing through the orifice.
Claim 6
Dependent Claim
30 words
The undirectional fluid valve of claim 1, wherein the flexible flap comprises crosslinked polyisoprene, is 0.35 to 0.45 millimeters thick, and has a Shore A hardness of 30 to 50.
Claim 7
Dependent Claim
28 words
The unidirectional fluid valve of claim 1, wherein the first portion of the flexible flap is attached to the valve seat beyond the area encompassed by the orifice.
Claim 8
Dependent Claim
28 words
The unidirectional fluid valve of claim 1, wherein the concave curvature of the seal ridge is defined by a polynomial mathematical equation of at least the third order.
Claim 9
Dependent Claim
35 words
The unidirectional fluid valve of claim 1, wherein the orifice has a cross-sectional area in the range of 2 to 6 cm 2 when viewed from a plane perpendicular to the direction of fluid flow.
Claim 10
Dependent Claim
18 words
The unidirectional fluid valve of claim 8, wherein the orifice is 3 to 4 cm 2 in size.
Claim 11
Dependent Claim
50 words
The unidirectional fluid valve of claim 1, wherein the first portion of the flexible flap is attached to a flap-retaining surface located on the exterior of the orifice beyond an outer extremity of the curved seal ridge, the point attachment being 1 to 3.5 mm from the curved seal ridge.
Claim 12
Dependent Claim
48 words
The unidirectional fluid valve of claim 10, wherein the flap-retaining surface traverses the valve seat over a distance at least as great as the width of the orifice, and the flap-retaining surface extends in a straight line in the direction to which the surface traverses the valve seat.
Claim 13
Dependent Claim
59 words
The unidirectional fluid valve of claim 1, wherein the concave curvature corresponds to the deformation curve exhibited by the second portion of the flexible flap when exposed to a force acting in the direction of gravity and having magnitude equal to a mass of the second portion of the flexible flap multiplied by 1.1 to 2 g of acceleration.
Claim 14
Dependent Claim
53 words
The unidirectional fluid valve of claim 12, wherein the concave curvature corresponds to the deformation curve exhibited by the second portion of the flexible flap when exposed to a force having a magnitude equal to a mass of the second portion of the flexible flap multiplied by 1.2 to 1.5 g of acceleration.
Claim 15
Dependent Claim
47 words
The unidirectional fluid valve of claim 13, wherein the concave curvature corresponds to the deformation curve exhibited by the flexible flap when exposed to a force having a magnitude equal to a mass of the second portion of the flexible flap multiplied by 1.3 g of acceleration.
Claim 16
Dependent Claim
46 words
The unidirectional fluid valve of claim 12, wherein the deformation curve corresponds to the deformation curve exhibited by the second portion of the flexible flap when secured at the first portion at an angle θ to the horizontal in the range of 25 to 65 degrees.
Claim 17
Dependent Claim
14 words
The undirectional fluid valve of claim 15, wherein the angle θ is about 45°.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-07-04 | 1998-01-03 | 1998-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-07-04 | 2002-01-03 | 2002-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-07-04 | 2006-01-03 | 2006-07-05 | $7700.00 | Window Closed / Lapsed |