| 摘要 |
<p>PURPOSE: To decide the flying angle of a golf ball accurately at the time of driving and heighten the ball flying speed by changing the shape of the cross-section of the shaft over the length of the shaft. CONSTITUTION: A cross-section of a shaft 1 changes from the flex point F as going toward each side, and the resistance moment of the contour cross-section decreases continuously about the axis z-z passing the vertical axis M-M of the shaft 1 and positioned perpendicularly to the driving direction (s) of the golf club. This decrease in the resistance moment generated by decrease of the cross-section area starts at the flex point F, decreases continuously toward the club head 3 till the bottom 2, and reaches finally the minimum resistance moment Wmin. Meantime on the side opposite the flex point F, the resistance moment decreases continuously till the point 21 as the position of distance (d) from the bottom of the top part 4, and on the side nearer the person concerned than the flex point F, this gives the minimum resistance moment Wmin.</p> |
