US4798547A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel efficient propulsor for outboard motors
Assignee: United States Department of the Navy
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Filing: 1987-06-29
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Granted: 1989-01-17
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Expires: 2007-06-29
Abstract
Abstract Vanes are mounted to an assembly affixed upstream of propeller blades of anutboard motor, creating a counterswirl in the fluid flow to counter the swirl produced by the propeller rotation, enabling on essentially axial discharge jet. The vanes are applied to only a 180 degree sector of the inflow to the propeller.
Inventors
- 👤 Walter S. Gearhart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:47
CPC Classifications
B; B63; B63H; B63H5/00; B63H5/07; B63H5/16; B63H20/00; F; F02; F02B; F02B61/00; F02B61/04; F02B61/045
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
81 words
A fuel efficient propulsor for a motorboat moving in a fluid, comprising: an outboard motor including a horizontal shaft having a propeller mounted thereon; and a vane assembly mounted forward of said propeller, said assembly comprising a plurality of stationary vanes applied to only one half of the fluid inflow to the propeller covering the inflow to the left hand side of the propeller looking forward, to produce a swirl in the fluid counter to the swirl generated at said propeller.
Claim 2
Dependent Claim
81 words
A fuel efficient propulsor for a motorboat moving in a fluid, comprising: an outboard motor including a horizontal shaft having a propeller mounted thereon; and a vane assembly mounted forward of said propeller, said assembly comprising a plurality of stationary vanes applied to only one half of the fluid inflow to the propeller covering the inflow to the left hand side of the propeller looking forward, to produce a swirl in the fluid counter to the swirl generated at said propeller.
Claim 3
Dependent Claim
25 words
A propulsor as recited in claim 1 wherein said plurality of vanes comprises five vanes unsymmetrically located about the axis of rotation of said propeller.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-01-17 | 1992-07-18 | 1993-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-17 | 1996-07-18 | 1997-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-17 | 2000-07-18 | 2001-01-17 | $7700.00 | Window Closed / Lapsed |