Patent ID: 6926569
Filing Date: 2005-08-09
Classification: A63B

Abstract:
1. A fin with a blade having adjustable closed area, comprising: a blade being lengthwise split into a plurality of sub-blades, so that said sub-blades are separated from one another from an outer end of said blade to a near central point of said blade; and at least one zipper being located between two said sub-blades that are adjacent to each other, said zipper being adapted to zip up for said adjacent sub-blades to provide a closed area, and said closed area being adjustable by zipping up said zipper by different length to thereby regulate a propulsive force that may be produced by said blade of said fin, wherein said zipper includes; two toothed zipper tapes that may be closed or separated from each other; a pull tab connected to said toothed zipper tapes for closing or separating said two zipper tapes; and a plastic frame connected to two lateral sides and an inner end of said zipper tapes with an outer periphery of said plastic frame connected to two adjacent edges of said two adjacent sub-blades, and wherein said plastic frame is provided along the outer periphery with a flange, and said adjacent sub-blades are provided along the adjacent edges with a groove corresponding to said flange.