Patent US3640240A successfully refreshed from Google Patents.
US3640240A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fin-propelled watercraft
Assignee: Individual
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Filing: 1969-10-23
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Granted: 1972-02-08
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Expires: 1989-10-23
Abstract
Abstract A floating body is operable to rock about a predetermined axis. A torsion-elastic fin stem is mounted on the floating body and substantially intersects the axis and has a free end portion extending from this body. A fin is secured to the free end portion and adapted to produce a thrust in response to a rocking motion of the body about the axis.
Inventors
- 👤 Erich Stein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:38
CPC Classifications
B; B63; B63H; B63H16/00; B63H16/02; B63H1/00; B63H1/30; B63H1/36
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
134 words
A watercraft comprising: a floating elongated body having a bow and a stern and adapted to rock about a longitudinal axis of the body extending from the bow to the stern; an elongated stem extending downwardly from said body substantially in the plane of and generally transverse to said axis at a location intermediate said bow and said stern, said stem being secured to said body but having a lower free end resiliently twistable relative to said body; and a fin attached to said free end at a forward portion of the said fin and with spacing below said body, said fin having an edge proximal to said body of lesser stiffness than the edge of said fin distal from said body, said fin having a trailing portion resiliently deflectable independently of said stem.
Claim 2
Dependent Claim
134 words
A watercraft comprising: a floating elongated body having a bow and a stern and adapted to rock about a longitudinal axis of the body extending from the bow to the stern; an elongated stem extending downwardly from said body substantially in the plane of and generally transverse to said axis at a location intermediate said bow and said stern, said stem being secured to said body but having a lower free end resiliently twistable relative to said body; and a fin attached to said free end at a forward portion of the said fin and with spacing below said body, said fin having an edge proximal to said body of lesser stiffness than the edge of said fin distal from said body, said fin having a trailing portion resiliently deflectable independently of said stem.
Claim 3
Dependent Claim
17 words
The watercraft defined in claim 1 further comprising means for mounting said stem movably on said body.
Claim 4
Dependent Claim
18 words
The watercraft defined in claim 1 wherein said stem is provided with an extension, runNing above said body.
Claim 5
Dependent Claim
19 words
The watercraft defined in claim 1 wherein said stem converges toward said axis in the direction of the bow.
Claim 6
Dependent Claim
17 words
The watercraft defined in claim 1 wherein said stem projects from said body perpendicularly to said axis.
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) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |