| 摘要 |
<p>PURPOSE:To make an attempt to increase the ball speed and to improve the ball direction by providing a shaft mounted on the neck portion of a head and by providing a means for improving an impact response to the end of the shaft that can be bent kinetically due to the impact to the head just at the time of hitting a ball and to the vicinity of the neck. CONSTITUTION:The end portion 14a of a shaft 14 is so formed that the portion differs from the upper portion in an impact response, namely the response to the impact at the end 14a of the shaft can be heightened. Furthermore the shaft is provided with a step 22, the upper portion of which is thick while the lower portion thereof is thin. The step 22 constitutes the upper limit of the end portion 14a, which heightens the response to the impact at the shaft 14 while the lower limit constitutes the end of the attachment part (mating part) to the neck portion 20. On the other hand, a core 24 with a high impact response is inserted into the end portion 14a of the shaft 14 so that the core closely adheres to the inside surface of the shaft 14. Thus the ball speed can be increased and the direction of the ball can be improved.</p> |
