Patent ID: 8690702
Filing Date: 2014-04-08
Classification: A63B

Abstract:
1. A golf club comprising: a shaft; and a golf club head with a hollow structure fixed to a tip end of the shaft and including a face portion having a face for hitting a ball, wherein the golf club has a reverse flex of 110 to 160 mm, and the face portion comprises a central thick part provided in a central region of the face portion, a toe-crown-side thin part provided on a crown-side and on a toe-side of the central thick part, and a heel-sole-side thin part provided on a sole-side and on a heel-side of the central thick part, wherein the central thick part has a substantially constant thickness largest in the face portion, the toe-crown-side thin part has a substantially constant thickness smallest in the face portion, the heel-sole-side thin part has a substantially constant thickness smallest in the face portion, the central thick part has an area of not less than 10% and not more than 30% of the overall area of the back surface of the face portion, the toe-crown-side thin part has an area of 8% to 20% of the overall area of the back surface of the face portion, the heel-sole-side thin part has an area of 3% to 10% of the overall area of the back surface of the face portion, in a front view of the golf club under its standard state in which the golf club is put on a horizontal plane at a lie angle and a loft angle which are specified for the golf club, a first straight line passing an area centroid of the toe-crown-side thin part and an area centroid of a back surface of the face portion has an angle θA of 10 to 30 degrees with respect to the horizontal plane, and a second straight line passing an area centroid of the heel-sole-side thin part and the area centroid of the back surface of the face portion has an angle θB of 36 to 40 degrees with respect to the horizontal plane, the toe-crown-side thin part is formed in a region between two straight lines intersecting at an area centroid SG at an angle αA of not less than 60 degrees and not more than 120 degrees, and the heel-sole-side thin part is formed in a region between two straight lines intersecting at the area centroid SG at an angle αB of not less than 60 degrees and not more than 120 degrees, wherein the area centroid SG is that of the back surface of the face portion.