Patent US3631828A successfully refreshed from Google Patents.
US3631828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sailboat hydrofoils
Assignee: Individual
•
Filing: 1970-01-19
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Granted: 1972-01-04
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Expires: 1990-01-19
Abstract
Abstract A hydrofoil craft having curved buoyant hydrofoils supporting a light frame which is driven by sail. During high winds the curved hydrofoils prevent the craft from ''''jumping'''' out of the water by creating a reverse or negative lift and in effect ''''hooking'''' the water.
Inventors
- 👤 Bernard Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:59
CPC Classifications
B; B63; B63B; B63B1/00; B63B1/02; B63B1/10; B63B1/14; B63B39/00; B63B39/06; B63B39/062
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
86 words
A hull-less boat comprising: a frame for carrying a load; a plurality of buoyant hydrofoils secured to said frame for supporting said frame above and out of contact with the water when said hydrofoils are immersed; each of said hydrofoils being concavo-convex in vertical section to yield high positive lift at low speeds when the foils are substantially fully immersed and negative lift at high speeds when only the lower extremities of the foils are still immersed; and means carried by the boat for propelling it.
Claim 2
Dependent Claim
86 words
A hull-less boat comprising: a frame for carrying a load; a plurality of buoyant hydrofoils secured to said frame for supporting said frame above and out of contact with the water when said hydrofoils are immersed; each of said hydrofoils being concavo-convex in vertical section to yield high positive lift at low speeds when the foils are substantially fully immersed and negative lift at high speeds when only the lower extremities of the foils are still immersed; and means carried by the boat for propelling it.
Claim 3
Dependent Claim
16 words
A hull-less boat as defined in claim 1 wherein said propelling means comprises a fixed sail.
Claim 4
Dependent Claim
43 words
A boat in accordance with claim 1 wherein said hydrofoils are three in number; two of said hydrofoils being secured to the boat for pivotal movement about a vertical axis and the other one of said hydrofoils is rigidly affixed to the boat.
Claim 5
Dependent Claim
34 words
A boat in accordance with claim 3 wherein each of said hydrofoils have a symmetrical foil-shaped end cross section whereby the foils may move in either of opposite directions and produce the same lift.
Claim 6
Dependent Claim
47 words
A boat in accordance with claim 4 wherein two of said hydrofoils each have an inner flat surface and an outer curved surface and each disposed with said flat side in substantially the same plane whereby movement of the foils in said plane produces a lift force.
Claim 7
Dependent Claim
92 words
A hydrofoil having a concavo-convex in vertical section along its vertical cross section arranged below the frame of a watercraft and comprising an upper and lower curved portion constructed and arranged in such a manner that as the speed of the craft increases, the craft rises and the foil emerges until at top speeds the craft rides only on the lower curve portion of the foil which is adapted to ''''hook'''' the water and prevent the craft from ''''jumping'''' out of the water by the creation of a negative or reverse lift.
Claim 8
Dependent Claim
92 words
A hydrofoil having a concavo-convex in vertical section along its vertical cross section arranged below the frame of a watercraft and comprising an upper and lower curved portion constructed and arranged in such a manner that as the speed of the craft increases, the craft rises and the foil emerges until at top speeds the craft rides only on the lower curve portion of the foil which is adapted to ''''hook'''' the water and prevent the craft from ''''jumping'''' out of the water by the creation of a negative or reverse lift.
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) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |