Shaft for golf club with overlapped joint

Abstract

The present invention provides a shaft for a golf club which is constructed such that overlapped joints are formed therein, thus providing effects of increasing the distance that a golf ball is driven, and of preventing the shaft of the golf club from momentarily twisting. To achieve the above-mentioned purpose, the shaft of the present invention includes an inner layer ( 110 ), which is provided at an innermost position, a middle layer ( 120 ), which is laminated around the circumferential outer surface of the inner layer, and an outer layer ( 130 ), which is laminated around the circumferential outer surface of the middle layer. The middle layer comprises a plurality of middle layer sheets, which are arranged in a longitudinal direction of the golf shaft such that the middle layer sheets partially overlap each other to form overlapped joints.

1 . A shaft for a golf club having an overlapped joint, comprising an inner layer provided at an innermost position, a middle layer laminated around a circumferential outer surface of the inner layer, and an outer layer laminated around a circumferential outer surface of the middle layer, wherein 
     the middle layer comprises a plurality of middle layer sheets arranged in a longitudinal direction of the golf shaft such that the middle layer sheets partially overlap each other to form an overlapped joint. 
   
   
       2 . The shaft for the golf club according to  claim 1 , wherein a joint protrusion is formed on a circumferential outer surface of the shaft of the golf club by the overlapped joint. 
   
   
       3 . The shaft for the golf club according to  claim 1 , wherein each of the middle layer sheets differs from an adjacent middle layer sheet in one or more of strength, elasticity and tonnage applied thereto. 
   
   
       4 . The shaft for the golf club according to  claim 1 , wherein the overlapped joint is formed in a direction perpendicular to the longitudinal direction of the golf shaft. 
   
   
       5 . The shaft for the golf club according to  claim 1 , wherein the overlapped joint is formed in a direction inclined with respect to the longitudinal direction of the golf shaft. 
   
   
       6 . The shaft for the golf club according to  claim 5 , wherein the middle layer comprises a first middle layer having an overlapped joint inclined upwards with respect to the longitudinal direction of the golf shaft, and a second middle layer having an overlapped joint inclined downwards with respect to the longitudinal direction of the golf shaft. 
   
   
       7 . The shaft for the golf club according to  claim 1 , wherein the inner layer is formed by laminating double-layered sheets, each of which has grains angled at a predetermined bias. 
   
   
       8 . The shaft for the golf club according to  claim 1 , wherein a triangular subsidiary sheet is wound between the inner layer and the middle layer to reinforce a shaft tip, the triangular subsidiary sheet being made of carbon fiber prepreg. 
   
   
       9 . The shaft for the golf club according to  claim 1 , wherein the middle layer is formed by laminating at least one sheet of carbon fiber prepreg having grains oriented in a longitudinal direction. 
   
   
       10 . The shaft for the golf club according to  claim 1 , wherein heat-shrink tape is wound around a circumferential outer surface of the outer layer.