Fins

Abstract

A fin includes a foot pocket and a web extended directly from the front end of the foot pocket, and a web flipper of the fin includes at least one pair of resistance reducing devices having at least one pair of window holes disposed on the web flipper; and a pair of vanes separately and pivotally coupled onto a side of the window hole by its plate and capable of swinging up and sown on a side of the window hole, and the web flipper is divided into left and right hard plates, and a soft material at the middle integrate the two hard plates as a whole.

1 . A fin, comprising a web directly extended from the front end of a foot pocket, wherein a web flipper of said fin comprises at least one pair of resistance reducing devices, each having at least one pair of window holes disposed on said web flipper and a pair of vanes separately and pivotally coupled onto a side of said window hole by its plate and capable of swinging up and down on a side of said window hole.  
   
   
       2 . The fin of  claim 1 , wherein said web flipper is divided into left and right hard boards and a soft material at the middle integrates said two hard boards.  
   
   
       3 . The fin of  claim 1 , wherein said resistance reducing device further comprises: 
 two axle barrels, disposed on both sides of said window hole on said web flipper respectively; and    an axle rod, installed on one side of said plate of said vane of said resistance reducing device;    such that said vane is pivotally coupled into said two axle barrels on a side of said window hole by said axle rod on a side of its plate, and upward and downward swinging motion are performed by using said axle barrel as a fulcrum.    
   
   
       4 . The fin of  claim 1 , wherein said resistance reducing device further comprises: 
 at least one bracket, installed on an upper side of said window hole of said web flipper; and    a flange, disposed at a lower edge of said window hole of said web flipper.