Golf Balls Having Dual-Layered Cores With Metal-Containing Centers and Thermoset Outer Cores
AssigneeAcushnet Company
InventorsMichael J. Sullivan, Mark L. Binette
Life of this patent
Estimating the term…
Abstract
Multi-piece golf balls containing a dual-core structure are provided. The core structure includes a small, heavy inner core (center) having a relatively high specific gravity and a surrounding outer core layer having a relatively low specific gravity. The core structure may have different hardness gradients. In one preferred embodiment, the inner core and outer core each has a positive hardness gradient. The center of the core comprises a metal material such as copper, steel, brass, tungsten, titanium, aluminum, and alloys thereof. The outer core layer preferably is formed from a thermoset composition such as polybutadiene rubber. The resulting ball has high resiliency and good spin control.
Claims8
A golf ball having a multi-layered core, comprising:
- i) an inner core comprising a metal material, the inner core having a diameter in the range of about 0.100 to about 1.100 inches, a specific gravity (SGinner), and an outer surface hardness (Hcenter surface) and a center hardness (Hcenter material), the Hcenter surface being the same or less than the Hcenter material to provide a zero or negative hardness gradient;
- and
- ii) an outer core layer comprising a thermoset material, the outer core layer being disposed about the inner core and having a thickness in the range of about 0.200 to about 1.200 inches, a specific gravity (SGouter), and an outer surface hardness ((Houter surface of OC) of 40 to 85 Shore D and an inner surface hardness (Hinner surface of OC) of 42 to 87 Shore D, the Houter surface of OC being the same or less than the Hinner surface of OC to provide a zero or negative hardness gradient, wherein the SGinner is greater than the SGouter, and the diameter of the inner core layer is less than the thickness of the outer core layer;
- and
- iii) a cover having at least one layer disposed about the multi-layered core.
A golf ball having a multi-layered core, comprising:
- i) an inner core comprising a metal material, the inner core having a diameter in the range of about 0.100 to about 1.100 inches, a specific gravity (SGinner), and an outer surface hardness (Hcenter surface) and a center hardness (Hcenter material), the Hcenter surface being the same or less than the Hcenter material to provide a zero or negative hardness gradient;
- and
- ii) an outer core layer comprising a thermoset material, the outer core layer being disposed about the inner core and having a thickness in the range of about 0.200 to about 1.200 inches, a specific gravity (SGouter), and an outer surface hardness ((Houter surface of OC) of 43 to 88 Shore D and an inner surface hardness (Hinner surface of OC) of 40 to 85 Shore D, the Houter surface of OC being greater than the Hinner surface of OC to provide a positive hardness gradient, wherein the SGinner is greater than the SGouter, and the diameter of the inner core layer is less than the thickness of the outer core layer;
- and
- iii) a cover having at least one layer disposed about the multi-layered core.
Dependencies are inferred from the claim text.