Patent US3556142A successfully refreshed from Google Patents.
US3556142A
Expired / Lapsed
US
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Fan protection valve
Assignee: United Aircraft Products Inc
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Filing: 1969-05-13
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Granted: 1971-01-19
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Expires: 1989-05-13
Abstract
Abstract Apparatus in a heat transfer system or the like. The open end of a duct normally supplied with air at high flow rates is controlled by a valve biased to a position of minimum restriction. Under conditions of high airflows, a created pressure difference moves the valve toward a position of maximum restriction. A fan, located in the duct to induce air flow in the absence of the normal supply, is protected thereby from damage caused by excessive windmilling.
Inventors
- 👤 Le Roy J Sabin
- 👤 Paul R Hughes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:42
CPC Classifications
F; F16; F16K; F16K17/00; F16K17/20; F16K17/22; F16K17/24; F16K17/28; F16K17/30; F04; F04D; F04D29/00; F04D29/40; F04D29/42; F04D29/44; F04D29/46; F04D29/462; F04D29/464; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7837; Y10T137/7869; Y10T137/8593; Y10T137/85978; Y10T137/85986; Y10T137/86002; Y10T137/86019
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
94 words
Apparatus interposed in an current of high flow including a duct having an entrance end admitting said air current, a normally inactive fan in said duct selectively operable in the absence of said high flow air current to create an induced lower flow air current into said entrance end of said duct, and flow restriction means positioned at said entrance end of said duct for protecting said fan from windmilling damage during high air flows by automatically restricting airflow through said duct in response to said higher airflows while fully accommodating said induced airflows.
Claim 2
Dependent Claim
94 words
Apparatus interposed in an current of high flow including a duct having an entrance end admitting said air current, a normally inactive fan in said duct selectively operable in the absence of said high flow air current to create an induced lower flow air current into said entrance end of said duct, and flow restriction means positioned at said entrance end of said duct for protecting said fan from windmilling damage during high air flows by automatically restricting airflow through said duct in response to said higher airflows while fully accommodating said induced airflows.
Claim 3
Dependent Claim
50 words
Apparatus according to claim 1, wherein said flow restricting means includes a poppet type valve controlling airflow into the entrance end of said duct and responding to an air pressure difference to move toward a position of maximum flow restriction, said valve being biased to a position of minimum restriction.
Claim 4
Dependent Claim
42 words
Apparatus according to claim 2, characterized by spring means means means acting as a biasing agent upon said valve and constructed by said high flow air current and to be relatively superior ro pressure differences created by the lower flow air current.
Claim 5
Dependent Claim
67 words
Apparatus according to claim 1, wherein said flow restricting means is a valve controlling airflow into the entrance end of said duct and settable to positions of minimum and maximum restriction, said valve responding to the high flows of the first mentioned air current to move toward a position of minimum restriction, said biasing means being relatively unyielding to the lower flows of the inducted air current.
Claim 6
Dependent Claim
138 words
Apparatus according to claim 1, wherein said flow restricting means is a valve adapted to move toward a seat on the entrance end of said duct to reduce the presented flow area through which air may enter said duct and movable in the opposite direction to increase such flow area, said valve being mounted to be responsive to high airflows to reduce the flow area and being biased in the opposite direction. 6, Apparatus according to claim 5, wherein said entrance end of said duct is formed as an open end thereof in the axis of said fan, said valve being a poppet type valve mounted in said open end of said duct to reciprocate relatively thereto, further characterized by a compression spring based to urge said valve outwardly away from the said open end of said duct.
Claim 7
Dependent Claim
56 words
Apparatus according to claim 5, characterized by a manifold receiving the airflow and into which said entrance end of said ducts opens, said manifold having a relief valve controlled outlet in bypassing relation to said duct to accommodate air flows supplied to the entrance end of said duct in excess of flows permitted by said valve.
References Cited (Backward Citations)
US3255963A
Cited
US3406904A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-18 | 1974-07-20 | 1975-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-18 | 1978-07-20 | 1979-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-18 | 1982-07-20 | 1983-01-19 | $7700.00 | Window Closed / Lapsed |