Patent US4005732A successfully refreshed from Google Patents.
US4005732A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flapper valve with independent spring action
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1975-08-25
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Granted: 1977-02-01
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Expires: 1995-08-25
Abstract
Abstract An improvement in multi-flapper check valves wherein each flapper is urged toward closure by an independent spring or springs, thereby improving the valve response for closure.
Inventors
- 👤 Spencer P. Buckner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:00
CPC Classifications
F; F16; F16K; F16K15/00; F16K15/02; F16K15/03; F16K15/035; F16K15/036; F16K15/038; F16K15/033; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7837; Y10T137/7838; Y10T137/7839
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
115 words
An improved valve of the type having a body with a fluid flow conduit therethrough, a valve seat surrounding said flow conduit, valve members for sealing said fluid flow conduit, stationary shaft means extending diametrically across said flow conduit for pivotally supporting said valve members within said body, and hinges for supporting said valve members on said shaft means, wherein the improvement comprises at least one separate helical torsion spring encircling a portion of said shaft means for each valve member for biasing said valve member toward its closed position, one leg of which is in contact with said valve member and the other leg of which is in contact with a stationary stop means.
Claim 2
Dependent Claim
115 words
An improved valve of the type having a body with a fluid flow conduit therethrough, a valve seat surrounding said flow conduit, valve members for sealing said fluid flow conduit, stationary shaft means extending diametrically across said flow conduit for pivotally supporting said valve members within said body, and hinges for supporting said valve members on said shaft means, wherein the improvement comprises at least one separate helical torsion spring encircling a portion of said shaft means for each valve member for biasing said valve member toward its closed position, one leg of which is in contact with said valve member and the other leg of which is in contact with a stationary stop means.
Claim 3
Dependent Claim
21 words
The improved valve of claim 1 in which at least two of said helical torsion springs have different torsional spring constants.
Claim 4
Dependent Claim
94 words
An improved valve of the type having a body with a fluid flow conduit therethrough, a valve seat surrounding said flow conduit, valve members for sealing said fluid flow conduit, a shaft for pivotally supporting said valve members within said body, and hinges for supporting said valve members on said shaft, wherein the improvement comprises at least one separate helical torsion spring wound about said shaft for each valve member, one leg of said spring being in contact with said valve member and the other leg being in contact with a stationary stop shaft.
Claim 5
Dependent Claim
94 words
An improved valve of the type having a body with a fluid flow conduit therethrough, a valve seat surrounding said flow conduit, valve members for sealing said fluid flow conduit, a shaft for pivotally supporting said valve members within said body, and hinges for supporting said valve members on said shaft, wherein the improvement comprises at least one separate helical torsion spring wound about said shaft for each valve member, one leg of said spring being in contact with said valve member and the other leg being in contact with a stationary stop shaft.
Claim 6
Dependent Claim
25 words
The improved valve of claim 3 in which at least two of said helical torsion springs exert different amounts of force per degree of deflection.
Claim 7
Dependent Claim
115 words
An improved valve of the type having a body with a fluid flow conduit therethrough, a valve seat surrounding said flow conduit, valve members for sealing said flow conduit, a single stationary shaft extending diametrically across said flow conduit for pivotally supporting said valve members within said body, and hinges for supporting said valve members on said stationary shaft, wherein the improvement comprises at least one separate helical torsion spring encircling a portion of said stationary shaft for each valve member for biasing said valve member toward its closed position, one leg of which is in contact with said valve member and the other leg of which is in contact with a stationary stop means.
Claim 8
Dependent Claim
115 words
An improved valve of the type having a body with a fluid flow conduit therethrough, a valve seat surrounding said flow conduit, valve members for sealing said flow conduit, a single stationary shaft extending diametrically across said flow conduit for pivotally supporting said valve members within said body, and hinges for supporting said valve members on said stationary shaft, wherein the improvement comprises at least one separate helical torsion spring encircling a portion of said stationary shaft for each valve member for biasing said valve member toward its closed position, one leg of which is in contact with said valve member and the other leg of which is in contact with a stationary stop means.
Claim 9
Dependent Claim
124 words
An improved valve of the type having a body with a fluid flow conduit therethrough, a valve seat surrounding said flow conduit, valve members for sealing said fluid flow conduit, a first single stationary shaft extending diametrically across said flow conduit for pivotally supporting said valve members within said body, and hinges for supporting said valve members on said first stationary shaft, wherein the improvement comprises at least one separate helical torsion spring encircling a portion of said first stationary shaft for each valve member for biasing said valve member toward its closed position, one leg of which is in contact with said valve member and the other leg of which is in contact with a second shaft parallel to said first stationary shaft.
Claim 10
Dependent Claim
124 words
An improved valve of the type having a body with a fluid flow conduit therethrough, a valve seat surrounding said flow conduit, valve members for sealing said fluid flow conduit, a first single stationary shaft extending diametrically across said flow conduit for pivotally supporting said valve members within said body, and hinges for supporting said valve members on said first stationary shaft, wherein the improvement comprises at least one separate helical torsion spring encircling a portion of said first stationary shaft for each valve member for biasing said valve member toward its closed position, one leg of which is in contact with said valve member and the other leg of which is in contact with a second shaft parallel to said first stationary shaft.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-01 | 1980-08-02 | 1981-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-01 | 1984-08-02 | 1985-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-01 | 1988-08-02 | 1989-02-01 | $7700.00 | Window Closed / Lapsed |