Patent ID: 7914399

Claim:
A method of making a golf ball comprising a core having a center and at least one intermediate layer formed on the center, and a cover covering the core, and having many dimples on the surface thereof, the method comprising the steps of: (a) forming a spherical center, (b) forming an intermediate layer on the center by using two core half molds having a semi-spherical cavity to form a spherical core, (c) (i) molding a cover composition, formed from polyurethane-based thermoplastic elastomer, into a semi-spherical half-shell for the cover, (ii) covering the core with two of the half-shells and placing the covered core in a golf ball half mold having a semi-spherical cavity and many projections corresponding to the shape of the dimples in the cavity, (iii) press molding the covered core under heating to mold a golf ball with a cover having (1) a thickness of 0.1 to 0.8 mm in land portion having no dimple and (2) a thickness at the bottom of each dimple that differs from the thickness in land portions by no more than 0.2 mm and simultaneously form depressions in the surface of the intermediate layer at positions corresponding to the dimples through the cover, and (d) after cooling, opening the mold to take out a molded golf ball.