US3640071A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ducted propeller systems for marine vessels
Assignee: Hydroconic Ltd
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Filing: 1970-09-29
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Granted: 1972-02-08
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Expires: 1990-09-29
Abstract
Abstract In a ducted propeller system for ship propulsion, comprising a propeller working in a fixed propulsion nozzle and rudder blades or shutters disposed at the nozzle entry on either side of the central vertical fore-and-aft plane of the nozzle, the rudder blades are toed out and the angle of the toeing is varied up the height of each blade to correspond to the different nozzle flow entry conditions that obtain at different regions of the nozzle entry due to the effect of propeller rotation.
Inventors
- 👤 Ewan Christian Brew Corlett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:08
CPC Classifications
B; B63; B63H; B63H5/00; B63H5/07; B63H5/14
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
69 words
A ship''s ducted propeller system comprising a fixed propulsion nozzle and a propeller working therein, and nominally toed out rudder blades disposed at the nozzle entry on either side of the central vertical fore-and-aft plane of the nozzle, characterized in that the toeing angle of each rudder blade is different at different positions up its height to match the differing flow conditions at different regions of the nozzle entry.
Claim 2
Dependent Claim
69 words
A ship''s ducted propeller system comprising a fixed propulsion nozzle and a propeller working therein, and nominally toed out rudder blades disposed at the nozzle entry on either side of the central vertical fore-and-aft plane of the nozzle, characterized in that the toeing angle of each rudder blade is different at different positions up its height to match the differing flow conditions at different regions of the nozzle entry.
Claim 3
Dependent Claim
22 words
A system according to claim 1, wherein each rudder blade is twisted so that the toeing angle changes progressively up its height.
Claim 4
Dependent Claim
38 words
A system according to claim 1, wherein each rudder blade is divided at the horizontal diametral plane of the nozzle entry, the portion of the blade above this plane having a different toeing angle to the portion below.
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) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |