US3661111A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aerofoilboat
Assignee: Individual
•
Filing: 1969-10-24
•
Granted: 1972-05-09
•
Expires: 1989-10-24
Abstract
Abstract An aerofoilboat shaped with a concavity extending back from the bow, open at the front in the direction of forward motion and generally bounded at the sides and around the rear between the sides by the water surface, and with sufficient forward speed the aerofoilboat being raised and supported above the water surface primarily through an air cushion thereunder built up due to surface ground effect with forward motion of the aerofoilboat. It has a longitudinally shifting center of lift that moved toward the rear in a self adjusting trimming action as the boat moves higher and ground effects lift is lessened.
Inventors
- 👤 Alexander M Lippisch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:23
CPC Classifications
B; B63; B63B; B63B1/00; B63B1/16; B63B1/32; B63B1/322; Y; Y02; Y02T; Y02T70/00; Y02T70/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
163 words
An aerofoilboat, supported above the water by utilizing an air cushion forming due to the ground effect phenomenon: having, a concavity open from the bow in the direction of forward motion of the aerofoilboat, and with the concavity, bounded below, generally, by the water surface; a propulsion unit with at least one propeller positioned for turning in water during operation; with aerofoilboat forward section designed to produce relatively low lift in flight outside of ground effect and provide a ground effect center of lift forward from an aerodynamic component center of lift; with an aerodynamic lift airFoil section of the airfoilboat located toward the rear, producing an increasing portion of the total aerofoilboat lift as the boat moves progressively higher in the ground effect zone of operation, and producing higher lift in flight outside of ground effect; and with said propulsion unit a powerplant positioned in a center cut-out area of the boat close to the center of gravity in the boat''s body.
Claim 2
Dependent Claim
163 words
An aerofoilboat, supported above the water by utilizing an air cushion forming due to the ground effect phenomenon: having, a concavity open from the bow in the direction of forward motion of the aerofoilboat, and with the concavity, bounded below, generally, by the water surface; a propulsion unit with at least one propeller positioned for turning in water during operation; with aerofoilboat forward section designed to produce relatively low lift in flight outside of ground effect and provide a ground effect center of lift forward from an aerodynamic component center of lift; with an aerodynamic lift airFoil section of the airfoilboat located toward the rear, producing an increasing portion of the total aerofoilboat lift as the boat moves progressively higher in the ground effect zone of operation, and producing higher lift in flight outside of ground effect; and with said propulsion unit a powerplant positioned in a center cut-out area of the boat close to the center of gravity in the boat''s body.
Claim 3
Dependent Claim
22 words
The aerofoiboat of claim 1, including airfoils, with convex top surfaces and concave bottom surfaces, attached to the sides of the boat.
Claim 4
Dependent Claim
27 words
The aerofoil boat of claim 2, in a high speed configuration including, tail booms extended to the rear; and a stabilizer plane attached to the tail booms.
Claim 5
Dependent Claim
181 words
An aerofoilboat, supported above the water by utilizing an air cushion forming due to the ground effect phenomenon; having, a concavity open from the bow in the direction of forward motion of the aerofoilboat, and with the concavity, bounded below, generally, by the water surface; a propulsion unit with at least one propeller positioned for turning in water during operation; with aerofoilboat forward section designed to produce relatively low lift in flight outside of ground effect and provide a ground effect center of lift forward from an aerodynamic component center of lift; with an aerodynamic lift airfoil section of the aerofoilboat located toward the rear, producing an increasing portion of the total aerofoilboat lift as the boat moves progressively higher in the ground effect zone of operation, and producing higher lift in flight outside of ground effect; including airfoils with convex top surfaces and concave bottom surfaces, attached to the sides of the boat; and with said airfoils with lateral and rear edges generally at substantially the level of a common plane with the bottom of the body of the aerofoilboat.
Claim 6
Dependent Claim
181 words
An aerofoilboat, supported above the water by utilizing an air cushion forming due to the ground effect phenomenon; having, a concavity open from the bow in the direction of forward motion of the aerofoilboat, and with the concavity, bounded below, generally, by the water surface; a propulsion unit with at least one propeller positioned for turning in water during operation; with aerofoilboat forward section designed to produce relatively low lift in flight outside of ground effect and provide a ground effect center of lift forward from an aerodynamic component center of lift; with an aerodynamic lift airfoil section of the aerofoilboat located toward the rear, producing an increasing portion of the total aerofoilboat lift as the boat moves progressively higher in the ground effect zone of operation, and producing higher lift in flight outside of ground effect; including airfoils with convex top surfaces and concave bottom surfaces, attached to the sides of the boat; and with said airfoils with lateral and rear edges generally at substantially the level of a common plane with the bottom of the body of the aerofoilboat.
Claim 7
Dependent Claim
26 words
The aerofoilboat of claim 4, in a high speed congifuration including, tail booms extended to the rear; and a stabilizer plane attached to the tail booms.
Claim 8
Dependent Claim
26 words
The aerofoilboat of claim 1, in a high speed configuration including, tail booms extended to the rear; and a stabilizer plane attached to the tail booms.
Claim 9
Dependent Claim
158 words
An aerofoilboat, supported above the water by utilizing an air cushion forming due to the ground effect phenomenon: having, a concavity open from the bow in the direction of forward motion of the aerofoilboat, and with the concavity, bounded below, generally, by the water surface; a propulsion unit with at least one propeller positioned for turning in water during operation; with aerofoilboat forward section designed to produce relatively low lift in flight outside of ground effect and provide a ground effect center of lift forward from an aerodynamic component center of lift; with an aerodynamic lift airfoil section of the aerofoilboat located toward the rear, producing an increasing portion of the total aerofoilboat lift as the boat moves progressively higher in the ground effect zone of operation, and producing higher lift in flight outside of ground effect; in a high speed configuration including, tail booms extended to the rear; and a stabilizer plane attached to the tail booms.
Claim 10
Dependent Claim
158 words
An aerofoilboat, supported above the water by utilizing an air cushion forming due to the ground effect phenomenon: having, a concavity open from the bow in the direction of forward motion of the aerofoilboat, and with the concavity, bounded below, generally, by the water surface; a propulsion unit with at least one propeller positioned for turning in water during operation; with aerofoilboat forward section designed to produce relatively low lift in flight outside of ground effect and provide a ground effect center of lift forward from an aerodynamic component center of lift; with an aerodynamic lift airfoil section of the aerofoilboat located toward the rear, producing an increasing portion of the total aerofoilboat lift as the boat moves progressively higher in the ground effect zone of operation, and producing higher lift in flight outside of ground effect; in a high speed configuration including, tail booms extended to the rear; and a stabilizer plane attached to the tail booms.
References Cited (Backward Citations)
US1469796A
Cited
US3117545A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |