Shaft for golf club

Abstract

A golf club, includes a golf club head; a shaft including a tip end, an opposite butt end, and a reinforced section extending in a tip-to-butt direction from the tip end to 550 mm from the tip end, the golf club head being coupled to the shaft at the tip end, and including a pitch-based carbon fiber ply that is in only the reinforced section; and a grip being coupled to the shaft at the butt end.

What is claimed is: 
     
         1 . A golf club, comprising:
 a golf club head;   a shaft comprising a tip end, an opposite butt end, and a reinforced section extending in a tip-to-butt direction from the tip end to 550 mm from the tip end, the golf club head being coupled to the shaft at the tip end, and comprising a pitch-based carbon fiber ply that is in only the reinforced section; and   a grip being coupled to the shaft at the butt end.   
     
     
         2 . The golf club of  claim 1 , wherein an average bending stiffness of a butt end portion of the shaft is at least 3.70 times an average bending stiffness of a tip end portion of the shaft, the butt end portion extending in a butt-to-tip direction from the butt end to 150 mm from the butt end, and the tip end portion extending in a tip-to-butt direction from the tip end to 300 mm from the tip end. 
     
     
         3 . The golf club of  claim 1 , wherein a smallest diameter of the shaft is less than 0.310 inches. 
     
     
         4 . The golf club of  claim 1 , wherein the pitch-based carbon fiber ply is a substantially 0 degree ply. 
     
     
         5 . The golf club of  claim 1 , wherein the pitch-based carbon fiber ply is a substantially 45 degree ply, and the shaft further comprises another pitch-based carbon fiber ply that is a substantially negative 45 degree ply. 
     
     
         6 . The golf club of  claim 1 , wherein the shaft further comprises another pitch-based carbon fiber ply that extends substantially along the full length of the shaft. 
     
     
         7 . The golf club of  claim 1 , wherein a mass of the shaft is less than 50 g, a mass of the grip is less than 40 g, and a mass ratio of the mass of the shaft to the mass of the grip is within a range of 1.1 to 1.3. 
     
     
         8 . A golf club shaft, the shaft comprising:
 a tip end;   an opposite butt end;   a tip end portion extending in a tip-to-butt direction from the tip end to 300 mm from the tip end;   a butt end portion extending in a butt-to-tip direction from the butt end to 150 mm from the butt end; and   a pitch-based carbon fiber ply,   wherein an average bending stiffness of the butt end portion of the shaft is at least 3.70 times an average bending stiffness of the tip end portion of the shaft.   
     
     
         9 . The golf club shaft of  claim 8 , wherein the average bending stiffness of the butt end portion of the shaft is at least 4.20 times the average bending stiffness of the tip end portion of the shaft. 
     
     
         10 . The golf club shaft of  claim 8 , wherein the pitch-based carbon fiber ply is in only the tip end portion of the shaft. 
     
     
         11 . The golf club shaft of  claim 10 , wherein a smallest diameter of the shaft along the tip end portion is less than 0.315 inches. 
     
     
         12 . The golf club shaft of  claim 8 , wherein a maximum rate of change of bending stiffness in the tip-to-butt direction in the shaft between the tip end portion and the butt end portion is at least 2.0 kg/(in*mm). 
     
     
         13 . A golf club shaft, the shaft comprising:
 a tip end;   an opposite butt end;   a tip end portion extending in a tip-to-butt direction from the tip end to 300 mm from the tip end;   a butt end portion extending in a butt-to-tip direction from the butt end to 150 mm from the butt end; and   a pitch-based carbon fiber ply that is at least partially in the tip end portion,   wherein a smallest diameter of the shaft in the tip end portion is less than 0.330 inches.   
     
     
         14 . The golf club shaft of  claim 13 , wherein the tip end portion is less than 0.315 inches. 
     
     
         15 . The golf club shaft of  claim 14 , wherein the tip end portion is less than 0.300 inches. 
     
     
         16 . The golf club shaft of  claim 15 , wherein the tip end portion is less than 0.290 inches. 
     
     
         17 . The golf club shaft of  claim 13 , wherein the pitch-based carbon fiber ply is in only the tip end portion of the shaft. 
     
     
         18 . The golf club shaft of  claim 13 , wherein the pitch-based carbon fiber ply is a substantially 45 degree ply. 
     
     
         19 . The golf club shaft of  claim 13 , wherein the pitch-based carbon fiber ply is a substantially 0 degree ply. 
     
     
         20 . The golf club shaft of  claim 13 , wherein an average bending stiffness in the tip end portion is greater than 150 kg/in.