Butt-mounted shaft extension device

Abstract

A device designed for modifying the length of a golf club shaft. The device is a three-piece mechanism with a bottom part bonded into the top end of a tubular golf club shaft, a top part provided within the grip, a threaded screw provided within the top part and threadably connected to the bottom part such that movement of the screw will adjust the distance between the top part and bottom part thereby adjusting the club length. The extension device is hidden within the shaft and grip and does not require a custom grip or shaft.

What is claimed is: 
     
         1 . An extension device for use on a butt-end of a golf club shaft, comprising:
 a grip secured to an upper end of a golf club shaft, the top end of the grip having a threaded cavity; and   a plurality of grip inserts having different lengths, the inserts having threaded protrusions,   wherein the grip insert having the desired length may be selected, whereby the threaded protrusion of the grip insert engages the threaded cavity of the grip such that the grip insert is secured to the grip resulting in a club that has a desired length.   
     
     
         2 . The extension device of  claim 1 , wherein the grip inserts have lengths such that the resulting club length may be varied by about 0 to about 5 inches. 
     
     
         3 . The extension device of  claim 2 , wherein the grip inserts have lengths such that the resulting club length may be varied by about 0 to about 2 inches. 
     
     
         4 . The extension device of  claim 3 , wherein the grip inserts have lengths such that the resulting club length may be varied by about 0 to about 1 inch. 
     
     
         5 . The extension device of  claim 1 , wherein at least three grip inserts are provided having different lengths. 
     
     
         6 . The extension device of  claim 5 , wherein one of the grip inserts results in a desired club length that is a standard club length. 
     
     
         7 . The extension device of  claim 5 , wherein one of the grip inserts results in a desired club length that is a shorter than standard club length by 0.5 to 2 inches. 
     
     
         8 . The extension device of  claim 5 , wherein one of the grip inserts results in a desired club length that is a longer than standard club length by 0.5 to 2 inches. 
     
     
         9 . The extension device of  claim 1 , wherein the grip inserts have different weights to alter the weight of the grip by 1 to 60 grams. 
     
     
         10 . The extension device of  claim 9 , wherein the grip inserts have different weights to alter the weight of the grip by 5 to 40 grams. 
     
     
         11 . An extension device for use on a butt-end of a golf club shaft, comprising:
 a grip secured to an upper end of a golf club shaft, the top end of the grip having an attachment mechanism; and   a plurality of grip inserts having different lengths, the inserts having a reciprocating attachment mechanism,   wherein the grip insert having the desired length may be selected, whereby the reciprocating attachment mechanism of the grip insert engages the attachment mechanism of the grip such that the grip insert is secured to the grip resulting in a club that has a desired length.   
     
     
         12 . The extension device of  claim 11 , wherein the attachment mechanism and reciprocating attachment mechanism include a snap-fit attachment mechanism for attaching the grip inserts to the top end of the grip.