US3589830A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of and apparatus for controlling a variable pitch steering propeller
Assignee: KARLSTAD MEKANISKA AB
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Filing: 1969-04-30
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Granted: 1971-06-29
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Expires: 1989-04-30
Abstract
Abstract A variable pitch steering propeller for a ship is controlled by continuously monitoring the power supplied to the propeller to drive it and producing a signal indicative thereof, generating a reference signal indicative of a desired propeller power output, comparing the two signals and producing a control signal representative of the difference between the actual power signal and the reference signal and adjusting the pitch of the propeller in accordance with the control signal.
Inventors
- 👤 Olof Rolf Gosta Mogren
- 👤 Tord Birger Svensson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:19
CPC Classifications
B; B63; B63H; B63H3/00; B63H3/10; B63H25/00; B63H25/46; G; G05; G05D; G05D1/00; G05D1/02; G05D1/0206
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
139 words
A method of controlling the load on an electric motor used to drive a variable pitch steering propeller of a ship comprising: generating a first electrical signal indicative of the current flow into the electric motor and therefore indicative of the actual load on the motor; generating a second electrical signal indicative of a load for the electric motor selected by the operator, this load not exceeding the maximum desirable load for the motor; comparing the first and second signals and generating a third electrical signal indicative of the difference therebetween, the third signal being indicative of the difference, if any, between the actual load and the selected load; and using the third signal to control the pitch of the steering propeller whereby the actual load on the motor is adjusted and made substantially equal to the selected load.
Claim 2
Independent Claim
139 words
A method of controlling the load on an electric motor used to drive a variable pitch steering propeller of a ship comprising: generating a first electrical signal indicative of the current flow into the electric motor and therefore indicative of the actual load on the motor; generating a second electrical signal indicative of a load for the electric motor selected by the operator, this load not exceeding the maximum desirable load for the motor; comparing the first and second signals and generating a third electrical signal indicative of the difference therebetween, the third signal being indicative of the difference, if any, between the actual load and the selected load; and using the third signal to control the pitch of the steering propeller whereby the actual load on the motor is adjusted and made substantially equal to the selected load.
Claim 3
Dependent Claim
31 words
The method according to claim 1 wherein the step of generating the first signal comprises passing at least a pOrtion of the current flowing into the motor through a current generator.
Claim 4
Dependent Claim
28 words
The method according to claim 1 wherein the step of generating the second signal includes the manipulation of a manually operable control on the bridge of the ship.
Claim 5
Dependent Claim
103 words
A ship having a steering propeller of variable pitch disposed within a tunnel extending athwart the hull of the ship and an electric motor for driving the steering propeller wherein the improvement comprises, a means for generating a first electrical signal indicative of the current flow into the motor, a means for generating a second electrical signal indicative of a selected load for the motor, a comparitor means arranged to receive said first and second electrical signals for generating a third electrical signal indicative of the difference therebetween, and means for adjusting the pitch of the propeller in response to the third signal.
Claim 6
Dependent Claim
103 words
A ship having a steering propeller of variable pitch disposed within a tunnel extending athwart the hull of the ship and an electric motor for driving the steering propeller wherein the improvement comprises, a means for generating a first electrical signal indicative of the current flow into the motor, a means for generating a second electrical signal indicative of a selected load for the motor, a comparitor means arranged to receive said first and second electrical signals for generating a third electrical signal indicative of the difference therebetween, and means for adjusting the pitch of the propeller in response to the third signal.
Claim 7
Dependent Claim
36 words
The apparatus of claim 4 wherein the means for generating the first electrical signal comprises a current generator arranged so that at least a portion of the current supplied to the electric motor flows through it.
Claim 8
Dependent Claim
31 words
The apparatus of claim 5 wherein the means for adjusting the pitch of the propeller includes a hydraulic valve the position of which is variable in response to the third signal.
Claim 9
Dependent Claim
66 words
The apparatus of claim 4 wherein the pitch of the blades of the propeller is reversible whereby the direction of the transverse thrust for steering the ship produced by the propeller can be reversed without reversing the direction of rotation of the propeller, said improvement further comprising means for causing said propeller to assume a position of neutral pitch when the steering system is turned off.
Claim 10
Dependent Claim
13 words
The apparatus of claim 4 wherein said electric motor is a synchronous motor.
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) | 1974-06-28 | 1974-12-28 | 1975-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-28 | 1978-12-28 | 1979-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-28 | 1982-12-28 | 1983-06-29 | $7700.00 | Window Closed / Lapsed |