US4325154A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surfboard fin
Assignee: Individual
•
Filing: 1980-03-31
•
Granted: 1982-04-20
•
Expires: 2000-03-31
Abstract
Abstract A surfboard fin is disclosed which is formed of shaped plastic opposed members which are joined and sealed to form a hollow light-weight buoyant construction, which provides an external contour to reduce drag in surfboarding. The novel profiled plastic surfboard fin is readily mounted to conventional boards and replaces the present conventional fiberglass fins.
Inventors
- 👤 William E. Collum, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:51
CPC Classifications
B; B63; B63B; B63B41/00; B63B32/00; B63B32/60; B63B32/66
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
105 words
A surfboard fin consisting of a body formed of molded plastic being formed as a hollow cavity so as to be buoyant, and means connected to the body to join said body to a surfboard; said plastic extending outwardly from said means so as to provide an outwardly extending external contour and fin profile so as to reduce drag on said fin while imparting buoyancy to the surfboard, said outwardly extending plastic being formed with a pair of facingly disposed shoulders disposed on opposite sides of said means, and opposed side members curving downwardly from said shoulders to form said external contour and fin profile.
Claim 2
Dependent Claim
105 words
A surfboard fin consisting of a body formed of molded plastic being formed as a hollow cavity so as to be buoyant, and means connected to the body to join said body to a surfboard; said plastic extending outwardly from said means so as to provide an outwardly extending external contour and fin profile so as to reduce drag on said fin while imparting buoyancy to the surfboard, said outwardly extending plastic being formed with a pair of facingly disposed shoulders disposed on opposite sides of said means, and opposed side members curving downwardly from said shoulders to form said external contour and fin profile.
Claim 3
Dependent Claim
19 words
The surfboard fin of claim 1, said body comprising two opposed contoured members and means to join said members.
Claim 4
Dependent Claim
23 words
The surfboard fin of claim 2, said means to join said members comprising screw means disposed within said cavity and interconnecting said members.
Claim 5
Dependent Claim
21 words
The surfboard fin of claim 3, said members having opposed matching edges and further comprising a sealant disposed at said edges.
Claim 6
Dependent Claim
52 words
The surfboard fin of claim 2, said means to join said members comprising one of said members being formed with recessed internal screw threads and the other member being formed with a coaxial bore whereby a screw passes through said bore and into said recessed threads so as to join said members.
Claim 7
Dependent Claim
37 words
The surfboard fin of claim 2, said means to join said members further comprising a block connected to said body, said block comprising a tongue to be received in the recess on the underside of a surfboard.
Claim 8
Dependent Claim
20 words
The surfboard fin of claim 6, said block being formed so as to receive said means to join said members.
Claim 9
Dependent Claim
11 words
The surfboard fin of claim 1, said plastic comprising a polycarbonate.
Claim 10
Dependent Claim
11 words
The surfboard fin of claim 1, said body being fluid tight.
Claim 11
Dependent Claim
12 words
The surfboard fin of claim 1, wherein said members comprise translucent plastic.
Claim 12
Dependent Claim
28 words
The surfboard fin of claim 10, wherein the inside surface of said translucent plastic provides a decoration receiving surface, whereby the decoration is viewable through the translucent plastic.
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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) | 1985-04-19 | 1985-10-19 | 1986-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-19 | 1989-10-19 | 1990-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-19 | 1993-10-19 | 1994-04-20 | $7700.00 | Window Closed / Lapsed |