Golf clubs and golf club sets

Abstract

A golf club set in which the attenuation rate of torque oscillation of club shafts is optimized for every individual club. The attenuation rate of torque oscillation of club shafts is controlled so as to be larger as the corresponding loft angles of the clubs increase.

What is claimed:  
     
         1 . A golf club set comprising a plurality of individual golf clubs having progressively increasing loft angles, wherein each golf club comprises a grip for grasping, a head for hitting a ball and a shaft connected between the grip and head; and 
 the attenuation rate of torque oscillation of the shaft of each of the individual golf clubs increases as the corresponding loft angles of each of the individual golf clubs increase.    
     
     
         2 . A golf club set according to    claim 1   , wherein a torque angle of the shaft of each of the individual golf clubs is proportional to the progression of the loft angles.  
     
     
         3 . A golf club set according to    claim 1   , wherein attenuation rate of torque oscillation of the shaft of the individual golf clubs increases by a unit of about ten percent for each five-degree increase of the loft angle.  
     
     
         4 . A golf club set according to    claim 1   , wherein the attenuation rate of torque oscillation of the shafts is controlled by surrounding at least a portion of a core of each shaft by a material having a predetermined attenuation rate of torque oscillation.  
     
     
         5 . A golf club set according to    claim 4   , wherein said material having a predetermined attenuation rate of torque oscillation comprises composite fibers mainly including carbon.  
     
     
         6 . A golf club set according to    claim 4   , wherein said material having a predetermined attenuation rate of torque oscillation comprises boron fibers.  
     
     
         7 . A golf club set according to    claim 4   , wherein said material having a predetermined attenuation rate of torque oscillation is provided along less than a full length of the shaft.  
     
     
         8 . A golf club set comprising a plurality of individual golf clubs having progressively increasing loft angles, wherein each golf club comprises a grip for grasping, a head for hitting a ball and a shaft connected between the grip and head; and 
 the attenuation rate of torque oscillation of the shaft of each of the individual golf clubs is substantially constant for each of the individual golf clubs.    
     
     
         9 . A golf club set according to    claim 8   , wherein a torque angle of the shaft of each of the individual golf clubs is proportional to the progression of the loft angles.  
     
     
         10 . A golf club comprising: 
 a grip for grasping;    a head for hitting a ball; and    a shaft connected between the grip and head, wherein the shaft has an attenuation rate of torque oscillation which is maintained between about 0.044 to about 0.076.    
     
     
         11 . A golf club according to    claim 10   , wherein the attenuation rate of torque oscillation is calculated by the following formula:  
       δ=({fraction (1/10)})  ln  ( A 1/ A 10)  
       where “A1” indicates the peak of an initial oscillation, and “A10” indicates the peak of the following 10th oscillation.