Patent US3911845A successfully refreshed from Google Patents.
US3911845A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sailing hydrofoil craft
Assignee: Individual
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Filing: 1972-05-17
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Granted: 1975-10-14
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Expires: 1992-05-17
Abstract
Abstract A monohull sailing hydrofoil craft having one or more foils on either side of the craft arranged so that the heel of the craft caused by the wind whilst sailing causes the windward foil or foils to lift clear of the water without any action by the helmsman, the foils being designed so that the righting force they apply by virtue of their shape and without the action of any buoyancy in the foils is such as to counteract the heeling forces.
Inventors
- 👤 Gerald Herbert Holtom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:35
CPC Classifications
B; B63; B63B; B63B1/00; B63B1/16; B63B1/24; B63B35/00; B63B2035/009
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
199 words
A sailing craft comprising: a monohull with accommodation for a helmsman, outrigger means extending in an athwartship''s direction either side of the monohull, at least one port and starboard hydrofoil having a negative buoyancy characteristic mounted rigidly on the outboard end of the outrigger means, the leading edge of the port and starboard hydrofoils being shaped so as to be parallel with the fore and aft line of the craft, the entire lower surface of at least the trailing portion of each hydrofoil being disposed at an angle outwardly turned with respect to a fore and aft line, divergent in plan and downwardly convergent in an athwartships vertical plane to exert a righting moment on the craft when submerged during forward movement having a horizontal component acting in opposition to the horizontal component of the force of the wind on the sail, said hydrofoils being slightly dished between said leading edge said trailing portion, and said hydrofoils being mounted to position the lowermost extremities of both said hydrofoils substantially no lower than the designed water level, wheReby the heel of the craft when sailing raises the windward hydrofoil above the water and at least partially submerges the leeward hydrofoil.
Claim 2
Dependent Claim
199 words
A sailing craft comprising: a monohull with accommodation for a helmsman, outrigger means extending in an athwartship''s direction either side of the monohull, at least one port and starboard hydrofoil having a negative buoyancy characteristic mounted rigidly on the outboard end of the outrigger means, the leading edge of the port and starboard hydrofoils being shaped so as to be parallel with the fore and aft line of the craft, the entire lower surface of at least the trailing portion of each hydrofoil being disposed at an angle outwardly turned with respect to a fore and aft line, divergent in plan and downwardly convergent in an athwartships vertical plane to exert a righting moment on the craft when submerged during forward movement having a horizontal component acting in opposition to the horizontal component of the force of the wind on the sail, said hydrofoils being slightly dished between said leading edge said trailing portion, and said hydrofoils being mounted to position the lowermost extremities of both said hydrofoils substantially no lower than the designed water level, wheReby the heel of the craft when sailing raises the windward hydrofoil above the water and at least partially submerges the leeward hydrofoil.
Claim 3
Dependent Claim
36 words
The sailing craft of claim 1 wherein the hydrofoils are mounted to position the centre of pressure of the hydrofoils in substantially the same vertical plane as the centre of effort of the sail or sails.
Claim 4
Dependent Claim
64 words
The sailing craft of claim 1 wherein the port and starboard hydrofoils are of a substantially triangular shape mounted so that the apex of the triangle downward, the side of the triangle opposite the apex being substantially parallel with the fore and aft designed water line, the two remaining sides being equal and the apex angle being between 90* and 110* and preferably 100*.
Claim 5
Dependent Claim
21 words
The sailing craft of claim 1 wherein the hull has a semi-circular cross-section at least amidships and below the water line.
Claim 6
Dependent Claim
28 words
The sailing craft of claim 1 wherein the trailing edge is turned outboard at an angle of 5* to 2 1/2 * to the fore and aft line.
Claim 7
Dependent Claim
38 words
The sailing craft of claim 1 wherein the outrigger means comprise port and starboard outriggers slidably mounted in the hull of the craft, whereby the beam of the craft can be reduced when the craft is not sailing.
Claim 8
Dependent Claim
28 words
The sailing craft of claim 1 wherein the area of the hydrofoil or hydrofoils on each side is between 4 1/2 % and 10% of the sails area.
Claim 9
Dependent Claim
18 words
The sailing craft of claim 1 wherein further hydrofoils are provided at or near the bow and stern.
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) | 1978-10-13 | 1979-04-14 | 1979-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-13 | 1983-04-14 | 1983-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-13 | 1987-04-14 | 1987-10-14 | $7700.00 | Window Closed / Lapsed |