| 摘要 |
<p>PURPOSE: To improve the hitting direction yet increasing the hitting speed by making the shaft to have an oval cross-section so that the direction of the major axis is parallel to the direction perpendicular to the hitting face at the center thereof. CONSTITUTION: Shaft 1 has an oval cross-section 10 defined by the major axis radius R and the minor axis radius (r) having a predetermined ratio therebetween, and head 2 is attached to shaft 1 so that the direction of the major axis radius R parallel to the direction perpendicular to the face 2a of head 2 at the center thereof. It is possible to swing the shaft at high speed in a predetermined direction and in a good direction due to the reduction of eddy currents 25 by the low air resistance 24 derived from the stream lined cross-section of shaft 1. When the ratio between the major axis radius and the minor axis radius falls within 1 < major axis radius/minor axis radius < 4, practical shaft is obtained and the air resistance and twisting of the shaft is effectively reduced.</p> |
