| abstract |
The present invention is directed to golf balls having a resilient inner core and outer core made of a material substantially free of fillers. The invention also encompasses golf balls wherein the inner and outer cores are not made of a thermoplastic material. The invention encompasses golf balls having an inner core, an outer core, an inner cover, and an outer cover wherein the inner core is encased by an outer core wherein the inner core has a volume greater than the outer core, inner cover, or outer cover and the inner core is made of a material substantially free of fillers. The volume relationship of the inner core (V 12 ), outer core (V 14 ), inner cover (V 16 ), and outer cover (V 18 ) is represented by the mathematical relationship: V 12 >2.5(V 14 +V 16 +V 18 ), wherein V 14 ≧V 18 ≧V 16 . Also, the inner core has a specific gravity ρ 12 , the outer core has a specific gravity ρ 14 , the inner cover has a specific gravity ρ 16 , and the outer cover has a specific gravity ρ 18 , wherein the relationship between the specific gravities is expressed by the mathematical expression: ρ 16 ≧ρ 18 ≧ρ 14 ≧ρ 12 . |