| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To improve ball hitting sound which a user feels, while minimizing the increase in weight of a golf club head. <P>SOLUTION: At least one rib which extends in a face back direction from a crown face is installed within a range of 15 mm each on the toe side and the heal side around a center upper part of the face surface of the inner surface of a metal hollow golf club head crown which the volume of the head is 420 cm<SP>3</SP>, the length from a head leading edge to the back part is 110 mm or longer and within the range of 10 to 30 mm in the face back direction from the crown face side end, and the curvature radius of the crown is 120 mm or longer. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
