Patent US3800727A successfully refreshed from Google Patents.
US3800727A
Expired / Lapsed
US
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Automatic landing system for hydrofoil craft
Assignee: Boeing Co
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Filing: 1972-12-06
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Granted: 1974-04-02
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Expires: 1992-12-06
Abstract
Abstract A control system for a hydrofoil characterized in that a transition from the foil-borne to the hull-borne mode of operation is initiated and the craft caused to descend or land automatically before an unsafe foil-borne roll or yaw attitude can be developed. This is achieved by providing an auxiliary electronic power source and auxiliary servo feedbacks in parallel with the main feedbacks for the control surface servos of the hydrofoil. The auxiliary feedbacks provide means for positioning the control surfaces to automatically land the craft upon the occurrence of a failure in the primary power source for the hydrofoil or some other off-normal condition.
Inventors
- 👤 D Stark
- 👤 I Hirsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 16:35
CPC Classifications
B; B63; B63B; B63B1/00; B63B1/16; B63B1/24; B63B1/28; B63B1/30
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
117 words
In a control syStem for a hydrofoil craft of the type having at least one control surface, electrical circuit means including a primary servo system for controlling said surface during normal operation of the hydrofoil, and a primary source of electrical power for said electrical circuit means, the combination of: auxiliary electrical circuit means including a secondary servo feedback system preset to automatically vary the position of said surface to cause said hydrofoil craft to descend from a foil-borne to a hull-borne mode of operation upon the occurrence of a failure in said primary power source, and a secondary source of electrical power for said auxiliary electrical circuit means separate and apart from said primary power source.
Claim 2
Dependent Claim
117 words
In a control syStem for a hydrofoil craft of the type having at least one control surface, electrical circuit means including a primary servo system for controlling said surface during normal operation of the hydrofoil, and a primary source of electrical power for said electrical circuit means, the combination of: auxiliary electrical circuit means including a secondary servo feedback system preset to automatically vary the position of said surface to cause said hydrofoil craft to descend from a foil-borne to a hull-borne mode of operation upon the occurrence of a failure in said primary power source, and a secondary source of electrical power for said auxiliary electrical circuit means separate and apart from said primary power source.
Claim 3
Dependent Claim
31 words
The combination of claim 1 wherein said primary source of electrical power comprises a source of alternating current power; and said secondary source of power comprises a direct current power source.
Claim 4
Dependent Claim
13 words
The combination of claim 2 wherein said direct current power source comprises batteries.
Claim 5
Dependent Claim
32 words
The combination of claim 1 wherein said hydrofoil craft includes a plurality of foils and a plurality of control surfaces each provided with a primary servo system and a secondary servo system.
Claim 6
Dependent Claim
41 words
The combination of claim 1 wherein both the primary servo system and the secondary servo system are employed to control said surface during normal foil-borne operation of the craft with the primary servo system dominating and overriding the secondary servo system.
Claim 7
Dependent Claim
123 words
In a control system for a hydrofoil craft of the type having forward and aft control surfaces, electrical circuit means including a primary servo system for controlling said surfaces during normal operation of the hydrofoil, and a primary source of electrical power for said electrical circuit means, the combination of: auxiliary electrical circuit means including a secondary servo feedback system preset to automatically rotate said forward control surface upwardly and said aft control surface downwardly to cause said hydrofoil craft to descend from a foil-borne to a hull-borne mode of operation upon the occurrence of a failure in said primary power source, and a secondary source of electrical power for said auxiliary electrical circuit means separate and apart from said primary power source.
Claim 8
Dependent Claim
123 words
In a control system for a hydrofoil craft of the type having forward and aft control surfaces, electrical circuit means including a primary servo system for controlling said surfaces during normal operation of the hydrofoil, and a primary source of electrical power for said electrical circuit means, the combination of: auxiliary electrical circuit means including a secondary servo feedback system preset to automatically rotate said forward control surface upwardly and said aft control surface downwardly to cause said hydrofoil craft to descend from a foil-borne to a hull-borne mode of operation upon the occurrence of a failure in said primary power source, and a secondary source of electrical power for said auxiliary electrical circuit means separate and apart from said primary power source.
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) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |