Patent US3789874A successfully refreshed from Google Patents.
US3789874A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Changing bias check valve
Assignee: Hersey Products Inc
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Filing: 1972-07-13
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Granted: 1974-02-05
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Expires: 1992-07-13
Abstract
Abstract A check valve in which clapper bias torque diminishes as the clapper opens, a clapper support carrying pivotally mounted thereon a clapper assembly and (pivotally mounted intermediately thereof) a cam arm, a compression spring extending between the clapper support and one end of the cam arm causing the other end of the cam arm to impose a bias force on the clapper assembly, the bias force being imposed along a plane defined by a transverse line near said other end of the cam arm and a transverse line on the clapper assembly. In a preferred embodiment the force is imposed from a stainless steel roller rotatably mounted in said other end of the cam arm to a plastic roller rotatably mounted at the downstream end of the clapper assembly.
Inventors
- 👤 D Hills
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:57
CPC Classifications
F; F16; F16K; F16K15/00; F16K15/02; F16K15/03; F16K15/033; F16K1/00; F16K1/24; F16K31/00; F16K31/44; F16K31/52; F16K31/524; F16K31/52408; F16K31/52441; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7837; Y10T137/7898; Y10T137/7904; Y10T137/7907
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
133 words
A check valve comprising: a clapper support, a clapper assembly rotatably mounted on said clapper support, a cam arm rotatably mounted intermediately thereof on said clapper support, a compression spring extending between said clapper support and a first end of said cam arm, and means securing said cam arm toward the other end thereof to said clapper assembly so that force is applied from said cam arm to said clapper assembly through a plane passing through an axis transverse of said cam arm toward said other end thereof and through an axis transverse of said clapper assembly wherein a cylindrical cam surface at said other end of said cam arm is urged against a cylindrical surface carried by said clapper assembly owing to the force on said cam arm from said compression spring.
Claim 2
Dependent Claim
133 words
A check valve comprising: a clapper support, a clapper assembly rotatably mounted on said clapper support, a cam arm rotatably mounted intermediately thereof on said clapper support, a compression spring extending between said clapper support and a first end of said cam arm, and means securing said cam arm toward the other end thereof to said clapper assembly so that force is applied from said cam arm to said clapper assembly through a plane passing through an axis transverse of said cam arm toward said other end thereof and through an axis transverse of said clapper assembly wherein a cylindrical cam surface at said other end of said cam arm is urged against a cylindrical surface carried by said clapper assembly owing to the force on said cam arm from said compression spring.
Claim 3
Dependent Claim
24 words
The check valve of claim 1 in which said cylindrical cam surface is the surface of a cylindrical element carried by said cam arm.
Claim 4
Dependent Claim
28 words
The check valve of claim 2 in which said cylindrical element is rotatably mounted on said cam arm for rotation about said axis transverse of said cam arm.
Claim 5
Dependent Claim
25 words
The check valve of claim 1 in which said cylindrical surface is the surface of a cylindrical clapper assembly element carried by said clapper assembly.
Claim 6
Dependent Claim
30 words
The check valve of claim 4 in which said cylindrical clapper assembly element is rotatably mounted on said clapper assembly for rotation about said axis transverse of said clapper assembly.
Claim 7
Dependent Claim
78 words
The check valve of claim 1 in which said cylindrical cam surface is the surface of a cylindrical element rotatably mounted on said cam arm for rotation about said axis transverse of said cam arm, said cylindrical surface is the surface of a cylindrical clapper assembly element rotatably mounted on said clapper asSembly for rotation about said axis transverse of said clapper assembly, and one of said cylindrical elements is plastic and the other thereof is stainless steel.
Claim 8
Dependent Claim
15 words
The check valve of claim 6 in which said clapper assembly cylindrical element is plastic.
Claim 9
Dependent Claim
42 words
The check valve of claim 6 in which said cam arm carries at said first end a spring engaging bushing engaging said compression spring, said spring engaging bushing being pivotally mounted on said cam arm to pivot about an axis transverse thereof.
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) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |