Patent ID: 9017187
Filing Date: 2015-04-28
Classification: A63B

Abstract:
1. A hollow golf club head comprising: a face for hitting a ball having a periphery and a face centroid, and a face peripheral portion extending rearward of the head from the periphery of the face and provided with only two reduced-rigidity portions, said each of the reduced-rigidity portions provided on the side of the hollow of the club head and consisting of a concave portion extending along the periphery of the face, said each of the reduced-rigidity portions having a depth in a range of from 0.2 to 1.0 mm and a width in a range of from 0.2 to 3.0 mm in a cross section perpendicular to a longitudinal direction of the concave portion, wherein in a standard state in which the head is placed on a horizontal plane so that a centerline of a shaft axis of the head is inclined at its lie angle within a vertical plane and the face is held at its loft angle, the reduced-rigidity portions consist of one toe-side reduced-rigidity portion provided on the toe side of the face centroid and one heel-side reduced-rigidity portion provided on the heel side of the face centroid, and when the head in the standard state is viewed from a direction of a normal of the face centroid, said toe-side reduced-rigidity portion has a center point P the heel-side reduced-rigidity portion has a center point P