Patent ID: 6520872
Filing Date: 2003-02-18
Classification: A63B

Abstract:
A three-piece solid golf ball comprising a center, an intermediate layer formed on the center and a cover covering the intermediate layer, of which the surface of the cover has many dimples, whereinthe center has a deformation amount of 4.0 to 6.0 mm, when applying from an initial load of 98 N to a final load of 1275 N, a central point hardness in Shore D hardness (HC) of 17 to 40, a surface hardness in Shore D hardness (HS) of 30 to 55 and a difference (HSâˆ’HC) between the surface hardness and central point hardness of 10 to 20, assuming that Shore D hardness at the distance of 5, 10 and 15 mm from the central point of the center is represented by H5, H10 and H15, respectively, the H5, H10 and H15 satisfy a correlation represented by the following formula: HC51015&lE;HS, and assuming that a distance from the central point of the center is represented by X (mm) and Shore D hardness at the distance X is represented by Y, the X and Y satisfy a correlation represented by the following formula: 0.7X+17&lE;Y&lE;0.8X+40 the intermediate layer is mainly formed from thermoplastic resin, and has a hardness in Shore D hardness (HM) of 48 to 62 and thickness of 1.0 to 1.8 mm, the cover is mainly formed from thermoplastic resin, and has a hardness in Shore D hardness (HL) of 58 to 72 and thickness of 1.0 to 2.5 mm, the HS, HM and HL satisfy a correlation represented by the following formula: HSMLand a hardness difference (HLâˆ’HM) is within the range of 5 to 15 and a hardness difference (HMâˆ’HS) is within the range of 10 to 20, and a number of the dimple having an angle between a radial tangent line (A) at the dimple edge and a tangent line (B) at the dimple edge of a circle drawn through the dimple edge and the deepest point of the dimple is within the range of 8 to 25Â° is not less than 50%, based on total number of the dimples in the golf ball.