Patent ID: 7655172

Claim:
A method of manufacturing a golf ball composed of a rubber core having a two-layer construction made up of an inner layer and an outer layer and a cover of at least one layer that encloses the rubber core using at least two vertically separating two-part molds of differing size cavities, each mold being composed of a top half and a bottom half, which are installed in such a way that the top mold halves are horizontally rotatable together and the bottom mold halves are horizontally rotatable together, said method comprising the steps of: (1) injecting an inner core layer-forming rubber composition into the cavities of a first top mold half and a first bottom mold half and vulcanizing the composition so as to form the inner core layer; and (2) rotating to a predetermined position a second top mold half or second bottom mold half having a cavity that is larger than the cavity of the first top mold half or first bottom mold half, placing the inner core layer formed in step (1) within the second top mold half or second bottom mold half, and injecting and vulcanizing an outer core layer-forming rubber composition so as to form the outer core layer over the inner core layer one hemisphere at a time, wherein the releasability between the core and mold halves is increased thus enabling injection molding of the inner and outer core layers to be consecutively carried out.