US3946690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Steering large vessels
Assignee: Shell USA Inc
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Filing: 1975-03-05
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Granted: 1976-03-30
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Expires: 1995-03-05
Abstract
Abstract A process and apparatus for stabilizing the course angle of a large ship by producing a signal when the measured variation of the course angle with time reaches an extreme value and utilizing said signal to reset the rudder over a discrete angle towards starboard if the said extreme value is in the starboard direction and towards port in the opposite case.
Inventors
- 👤 Leopold C. van Holtz
- 👤 Wouter K. Wolters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:46
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/02; G05D1/0206
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
117 words
A process for stabilizing the course angle of a large ship comprising: measuring the variation of the course angle with time and producing a course angle signal: producing a maximum course angle signal when the measured variation related thereto of the course angle with time reaches an extreme value; comparing said maximum course angle signal with the instantaneous course angle signal and producing a course stabilizing signal; and utilizing said course stabilizing signal to move the ship's rudder through a predetermined discrete angle relative to a neutral position, the rudder being reset towards starboard if the said extreme value is in the starboard direction and towards port if the said extreme value is in the port direction.
Claim 2
Dependent Claim
117 words
A process for stabilizing the course angle of a large ship comprising: measuring the variation of the course angle with time and producing a course angle signal: producing a maximum course angle signal when the measured variation related thereto of the course angle with time reaches an extreme value; comparing said maximum course angle signal with the instantaneous course angle signal and producing a course stabilizing signal; and utilizing said course stabilizing signal to move the ship's rudder through a predetermined discrete angle relative to a neutral position, the rudder being reset towards starboard if the said extreme value is in the starboard direction and towards port if the said extreme value is in the port direction.
Claim 3
Dependent Claim
30 words
The process of claim 1 in which the movement of the rudder from a neutral position in response to said course stabilizing signal is limited to between 2° and 5°.
Claim 4
Dependent Claim
19 words
The process of claim 1 in which the movement of the rudder in starboard and port directions are unequal.
Claim 5
Dependent Claim
29 words
The process of claim 1 in which normal steering changes in the rudder position are added to the movement of the rudder in response to the course stabilization signal.
Claim 6
Independent Claim
144 words
An apparatus for stabilizing the course angle of a ship comprising: course measuring means disposed on the ship to measure the actual course of said vessel and supply a course signal related thereto; peak amplitude measuring means, said peak amplitude measuring means being coupled to said course measuring means to detect the peak amplitude of said course signal; a subtracting circuit, said subtracting circuit being coupled to both said peak amplitude measuring means and said course measuring means to supply a difference signal related to the difference between said peak amplitude and the actual course; and switch means coupled to said subtracting circuit and responsive to said difference signal to move the rudder a predetermined discrete angle towards starboard if the said peak amplitude is in the starboard direction and towards port in the opposite case whenever said difference signal exceeds a preset limit.
Claim 7
Independent Claim
144 words
An apparatus for stabilizing the course angle of a ship comprising: course measuring means disposed on the ship to measure the actual course of said vessel and supply a course signal related thereto; peak amplitude measuring means, said peak amplitude measuring means being coupled to said course measuring means to detect the peak amplitude of said course signal; a subtracting circuit, said subtracting circuit being coupled to both said peak amplitude measuring means and said course measuring means to supply a difference signal related to the difference between said peak amplitude and the actual course; and switch means coupled to said subtracting circuit and responsive to said difference signal to move the rudder a predetermined discrete angle towards starboard if the said peak amplitude is in the starboard direction and towards port in the opposite case whenever said difference signal exceeds a preset limit.
Claim 8
Dependent Claim
27 words
The apparatus of claim 5 wherein the peak amplitude measuring means consists of a hold amplifier having an output connected to one input of the subtracting circuit.
Claim 9
Dependent Claim
32 words
The apparatus of claim 6 and in addition an adjustable threshold circuit, said subtracting circuit being coupled to said adjustable threshold circuit, said adjustable threshold circuit being coupled to said switch means.
References Cited (Backward Citations)
US3140436A
Cited
US3741474A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |