| US 7,591,736 B2 | ||
| Golf club head | ||
| Wataru Ban, Saitama (Japan) | ||
| Assigned to Bridgestone Sports Co., Ltd., Tokyo (Japan) | ||
| Filed on Dec. 22, 2006, as Appl. No. 11/643,763. | ||
| Claims priority of application No. 2005-378100 (JP), filed on Dec. 28, 2005. | ||
| Prior Publication US 2007/0149314 A1, Jun. 28, 2007 | ||
| Int. Cl. A63B 53/04 (2006.01) | ||
| U.S. Cl. 473—329 [473/332; 473/342; 473/345] | 12 Claims |
| 1. A hollow golf club head comprising:
a face portion;
a crown portion; and
a sole portion,
wherein assuming that a primary deflection mode frequency of the face portion is Ff, a primary deflection mode frequency of
the crown portion is Fc, and a primary deflection mode frequency of the sole portion is Fs, the Ff, Fc and Fs satisfy the
following expressions (1), (2) and (3),
3000 Hz<Ff<4000 Hz (1)
3000 Hz<Fc<4000 Hz (2)
Fs>4000 Hz (3)
and the face portion, the crown portion and the sole portion have no mode frequency of 3000 Hz or less,
wherein the face portion is a front portion of the golf club head for hitting a ball, the sole portion is a portion of the
golf club head extending from a lower part of the face portion backward and forming a bottom part of the golf club head, and
the crown portion is a portion of the golf club head extending backward from an upper part of the face portion and forming
an upper part of the golf club head, and
the golf club head has a hallow cavity defined therein.
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