Patent US3715571A successfully refreshed from Google Patents.
US3715571A
Expired / Lapsed
US
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Ship's turn rate control system
Assignee: Litton Marine Systems Inc
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Filing: 1971-06-07
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Granted: 1973-02-06
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Expires: 1991-06-07
Abstract
Abstract A conventional ship''s steering system is modified to limit the degree of heeling during turns by limiting the centrifugal force developed during such turns. The present invention utilizes the fact that centrifugal force is proportional to the product of a ship''s speed and turning rate. The ship''s speed and rate-of-turn are measured and multiplied in a computer. Rudder command signals are applied to the steering mechanism through a summing amplifier. The output of the computer is used to modify the characteristics of the amplifier to a value that maintains the computer output within the acceptable limits. Thus heel control is achieved by automatically regulating the rudder positioning control.
Inventors
- 👤 F Braddon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:26
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/02; G05D1/0206; B; B63; B63H; B63H25/00; B63H25/06; B63H25/08; B63H25/14; B63H25/18; B63H25/24; G06; G06G; G06G7/00; G06G7/48; G06G7/70
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
98 words
A ship''s turn rate limiting system for use with marine craft of a type in which the steering apparatus produces an electrical command signal that controls rudder angle through an electrical network, said limiting system including means to produce a first electrical signal indicative of the ship''s speed, means to produce a second electrical signal indicative of the ship''s turning rate, means to produce an electrical limiting signal proportional to the mathematical product of said first and second electrical signals and means to restrict the magnitude of said command signal as an inverse function of said limiting signal.
Claim 2
Dependent Claim
98 words
A ship''s turn rate limiting system for use with marine craft of a type in which the steering apparatus produces an electrical command signal that controls rudder angle through an electrical network, said limiting system including means to produce a first electrical signal indicative of the ship''s speed, means to produce a second electrical signal indicative of the ship''s turning rate, means to produce an electrical limiting signal proportional to the mathematical product of said first and second electrical signals and means to restrict the magnitude of said command signal as an inverse function of said limiting signal.
Claim 3
Dependent Claim
98 words
A ship''s turn rate limiting system for use with marine craft of a type in which the steering apparatus produces an electrical command signal that controls rudder angle through an electrical network, said limiting system including means to produce a first electrical signal indicative of the ship''s speed, means to produce a second electrical signal indicative of the ship''s turning rate, means to produce an electrical limiting signal proportional to the mathematical product of said first and second electrical signals and means to restrict the magnitude of said command signal as an inverse function of said limiting signal.
Claim 4
Dependent Claim
98 words
A ship''s turn rate limiting system for use with marine craft of a type in which the steering apparatus produces an electrical command signal that controls rudder angle through an electrical network, said limiting system including means to produce a first electrical signal indicative of the ship''s speed, means to produce a second electrical signal indicative of the ship''s turning rate, means to produce an electrical limiting signal proportional to the mathematical product of said first and second electrical signals and means to restrict the magnitude of said command signal as an inverse function of said limiting signal.
Claim 5
Dependent Claim
47 words
The system of claim 1 wherein the means to restrict the magnitude of the command signal includes a variable gain amplifier connected to provide the command signal, said amplifier being further connected and arranged so that its gain is decreased by an increase in said limiting signal.
References Cited (Backward Citations)
US2766952A
Cited
US3140436A
Cited
US3111105A
Cited
US3133520A
Cited
US3237107A
Cited
US3488427A
Cited
US3428788A
Cited
US3545398A
Cited
US3604907A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |