| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a hollow golf club head which increases the yardage by achieving a larger ball striking angle. <P>SOLUTION: In the hollow golf club head, the ratio of the rigidity of the sole part 32 to that of the crown part 34 is set to be 1:0.1-0.8. A crown lower-rigidity area (crown thin area 34a) is formed on the face side of the crown part and a crown high-rigidity area (crown thick area 34b) on its back side and the ratio of the rigidity of the crown high-rigidity area to that of the crown low-rigidity area is set to be 1:0.2-0.6. Otherwise, a sole high-rigidity area (sole thick area 32a) is formed on the face side of the sole part and a sole low rigidity area (sole thin area 32b) on its back side and the ratio of the rigidity of the sole high-rigidity area to that of the sole low-rigidity area should be 1:0.2-0.5. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
