US3747138A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrofoil surfboards
Assignee: Individual
•
Filing: 1970-10-26
•
Granted: 1973-07-24
•
Expires: 1990-10-26
Abstract
Abstract A wave riding, wave-propelled free body surfboard when underway along the surface of a wave is supported above the wave by hydrofoils having sufficient area, angle of attack and lift to support at least a portion of the surfboard above a surface of the water. The force diagram shown below is a diagram coplanar with the wave surface.
Inventors
- 👤 D Morgan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:07
CPC Classifications
B; B63; B63B; B63B32/00; B63B32/60; B63B32/64
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
155 words
A wave-propelled and wave-riding surfboard vehicle, comprising a long, narrow buoyant planing hull, devoid of towing and foot connections, for supporting a rider out of the water, to the bottom of which hull are attached and extend downward therefrom, a plurality of positively lifting hydrofoils having a size, configuration and angle of attack sufficient to lift at least portions of said wave-riding surfboard completely free from the water, so as to allow a rider thereupon to maneuver such wave-riding surfboard upon the forward face of water waves, as gravity induces such a wave-riding surfboard to slide down the incline presented by the wave''s face, and thereby to pass swiftly and efficiently over the surface of the water, the hydrofoils having leading and trailing edges angularly swept with respect to an elongated direction of the surfboard, an apex of roots of the hydrofoils falling in a normal plane bisecting the planing hull along a longitudinal axis.
Claim 2
Dependent Claim
155 words
A wave-propelled and wave-riding surfboard vehicle, comprising a long, narrow buoyant planing hull, devoid of towing and foot connections, for supporting a rider out of the water, to the bottom of which hull are attached and extend downward therefrom, a plurality of positively lifting hydrofoils having a size, configuration and angle of attack sufficient to lift at least portions of said wave-riding surfboard completely free from the water, so as to allow a rider thereupon to maneuver such wave-riding surfboard upon the forward face of water waves, as gravity induces such a wave-riding surfboard to slide down the incline presented by the wave''s face, and thereby to pass swiftly and efficiently over the surface of the water, the hydrofoils having leading and trailing edges angularly swept with respect to an elongated direction of the surfboard, an apex of roots of the hydrofoils falling in a normal plane bisecting the planing hull along a longitudinal axis.
Claim 3
Dependent Claim
23 words
A wave riding vehicle or surfboard as claimed in claim 1, which utilizes surface-piercing type hydrofoils which are directly connected to the hull.
Claim 4
Dependent Claim
36 words
A wave riding vehicle or surfboard as claimed in claim 1, which utilizes hydrofoils which have one part which is of the fully submerged type, and another part thereof which is of the surface piercing type.
Claim 5
Dependent Claim
39 words
A wave riding vehicle or surfboard as claimed in claim 1, which utilizes a hydrofoil assembly at the rear or tail end thereof, and a plain or ventilated type of Ramus step within the forward one-third of said surfboard.
Claim 6
Dependent Claim
40 words
A wave riding vehicle or surfboard as defined in claim 1, such that at least one hydrofoil is located within the front one-third of the board, and at least one hydrofoil is located within the rear one-third of said surfboard.
Claim 7
Dependent Claim
40 words
The invention as defined in claim 5, with at least one Ramus step located such as to assist the vehicle to attain foil borne operation, with the at least one step running generally transversely across the bottom of the board.
Claim 8
Dependent Claim
47 words
A wave riding vehicle or surfboard as claimed in claim 1, such that there being only one hydrofoil assembly, with that one hydrofoil located in the nose area such that the lift produced by that hydrofoil resists any tendency for the nose of the surfboard to submerge.
Claim 9
Dependent Claim
77 words
A wave riding vehicle or surfboard as claimed in claim 1, with means for attaching the hydrofoils to the bottom surface of the surfboard, such that the positions of the hydrofoils may be varied along the long axis of said board, and which also allows the interchangeability of different foils, which may vary as to number, size, shape, section, outline form, chord, twist, taper, angle of attack, sweep, type (surface piercing, fully submerged, ladder) and particularly area.
Claim 10
Dependent Claim
124 words
A wave riding vehicle or surfboard as claimed in claim 8, such that the aforementioned means for attachment shall consist of a channel or channels imbedded within the body of the surfboard along the longitudinal axis, and being of suitable durable material, with a dove-tail shaped recess running the length of the channel, and with tapped holes spaced periodically and uniformly along the length of such dove-tail recess, with such tapped holes being able to receive a suitable non-corrosive screw which passes freely, excluding head, through the hydrofoil strut or main body and into said tapped holes, to secure the hydrofoils rigidly to the surfboard body, and with the aforementioned channel having a wide spot which allows insertion and removal of such interchangeable hydrofoils.
Claim 11
Dependent Claim
39 words
Wave riding vehicle or surfboard as claimed in claim 1, equipped with hydrofoils which have wings in an assymetrical arrangement, such that the wings on each foil assembly are staggered or displaced along the long axis of said surfboard.
Claim 12
Dependent Claim
19 words
The wave-propelled surfboard of claim 1 in which the leading and trailing edges of the hydrofoils are swept backwards.
Claim 13
Dependent Claim
17 words
The wave-propelled surfboard of claim 1 in which the hydrofoils have leading and trailing edges swept forward.
References Cited (Backward Citations)
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Cited
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Cited
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Cited
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Cited
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |