Releasable spring-locking mechanism for rapid watercraft fin attachment

Abstract

The present invention provides fin attachment devices and methods based upon the concept of vertical, instead of horizontal, locking forces for fin attachment to watercraft. In some embodiments the spring force is employed as the actual locking mechanism, and insertion and desertion forces are designed into the spring. The spring may be designed so that the insertion force is less than the desertion force.

1 . A watercraft attachment system for releasably attaching a device to a watercraft, the system comprising:
 a receptacle attached to the watercraft dimensioned to releasably receive the device; and   a locking spring configured to lock the device into the receptacle;   wherein the locking spring is a canted coil spring.   
   
   
       2 . The system of  claim 1 , wherein the device comprises a fin. 
   
   
       3 . The system of  claim 1 , wherein the locking spring is disposed within an indention within the receptacle. 
   
   
       4 . The system of  claim 1 , wherein the locking spring is located on an indention in a post configured to be inserted into the receptacle. 
   
   
       5 . The system of  claim 1 , wherein the locking spring is located on a post attached to the device. 
   
   
       6 . The system of  claim 1 , wherein the locking spring is located on a post attached to the watercraft. 
   
   
       7 . The system of  claim 1 , wherein the locking spring is disposed within an groove. 
   
   
       8 . The system of  claim 7 , wherein the locking spring provides a locking force for securing the device in the groove. 
   
   
       9 . The system of  claim 8 , wherein the locking force provided by the spring is substantially parallel to an axis of the receptacle. 
   
   
       10 . A fin for a watercraft, comprising:
 a post having an groove; and   a canted-coil spring disposed within the groove.   
   
   
       11 . The fin of  claim 10 , wherein the groove is generally circular in shape. 
   
   
       12 . A fin box, comprising:
 a lower portion comprising an attachment device, the attachment device comprising an edge configured to attach the fin box to a fin cavity; and   an upper portion configured to attach the fin box to a fin.   
   
   
       13 . The fin box of  claim 12 , wherein the lower portion and the upper portion are coaxially aligned. 
   
   
       14 . The fin box of  claim 12 , wherein the edge comprises a cylindrical surface with a coarse pitched thread formed on the exterior of the cylindrical surface. 
   
   
       15 . The fin box of  claim 12 , wherein the fin box comprises an elongated box configuration with rounded distal ends. 
   
   
       16 . The fin box of  claim 12 , wherein the upper portion of the fin box further comprises a radially extending flange. 
   
   
       17 . The fin box of  claim 16 , wherein the radially extending flange further comprises a through hole configured to attach a fin to the fin box. 
   
   
       18 . The fin box of  claim 16 , further comprising a frusto-conical surface joining the radially extended flange and a base of the lower portion. 
   
   
       19 . The fin box of  claim 12 , wherein the attachment device comprises a wedge shaped lip configured to secure the fin box in the fin cavity. 
   
   
       20 . The fin box of  claim 12 , further comprising an annular groove on a top surface of the upper portion configured to couple the fin box to a fin. 
   
   
       21 . The fin box of  claim 12 , wherein the attachment device of the lower portion comprises a locking spring. 
   
   
       22 . The fin box of  claim 21 , wherein the locking spring is a canted coil spring. 
   
   
       23 . A releasable locking mechanism for a watercraft fin, comprising:
 an indention; and   a locking spring;   wherein the locking spring is for applying a spring force locking the fin into the indention.   
   
   
       24 . The releasable locking mechanism of  claim 23 , wherein the spring force on the locking spring is substantially vertical. 
   
   
       25 . A watercraft having a removable fin, the watercraft comprising:
 a watercraft body;   a fin box disposed in the watercraft body;   a removable fin disposed in the fin box; and   a releasable locking mechanism, comprising:
 an indention, and 
 a locking spring, 
 wherein the locking spring is for applying a engagement force locking the fin into the indention.