Hydrodynamic swim fin
US4737127A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 7, 1986 |
| Grant date | Apr 12, 1988 |
| Priority date | — |
| Expiry date | Oct 7, 2006 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA63B31/11
- WIPO fieldFurniture, games
- WIPO sectorOther fields
Abstract
An improved hydrodynamic swim fin utilizes a wing and a tail that are overlapped normally to provide a two-stage propulsion system. Ribs support the wing and tail and define flow channels. These ribs are parallel to each other and to the longitudinal axis of the fin whereby the effective area through which flow proceeds is uniform throughout the length of the fin. No parts of the ribs form barriers to the leading edges of the side wing segments whereby laminar flow is achieved. The fin part is maintained essentially rigid; however, the fin part is allowed limited angular movement about a defined transverse axis to achieve proper attack angle. Since the fin part is rigid, it maintains that attack angle throughout the length of the fin part. Trailing ends of the wing are individually flexible to produce greater opening for two-stage propulsion during the power downstroke, and to produce substantial closure for one-stage propulsion during the upstroke. Leading ends of the side wing segments are individually flexible to permit a truer hdyrofoil shape in response to angular movement of the fin part about the transverse axis. Deflectors prevent obstructions such as kelp from reaching the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.