Golf ball core having medium positive hardness gradient and high surface hardness
AssigneeAcushnet Company
InventorsMichael J. Sullivan, Brian Comeau, Dennis Britton
Life of this patent
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Abstract
A golf ball includes a single solid core having a surface hardness and a geometric center hardness. The core has an outer diameter of about 1.5 to 1.62 inches. An outer cover layer formed from a polyurea or polyurethane has a first hardness, and an inner cover layer, disposed between the core and the outer cover, has a second hardness greater than the first hardness and within 5 Shore C of the core surface hardness. The geometric center hardness is about 64 to 85 Shore C, and the core surface hardness is greater than 85 Shore C and harder than the geometric center hardness by about 5 to 22 Shore C to define a positive hardness gradient.
Claims20
A golf ball comprising:
- a single, unitary, homogeneous core having a surface hardness and a geometric center hardness, the core having an outer diameter of about 1.5 to about 1.62 inches;
- an outer cover layer comprising a polyurea, a polyurethane, or a hybrid thereof, and having a first hardness;
- and
- an inner cover layer disposed between the core and the outer cover layer, the inner cover layer having a second hardness greater than the first hardness and within 5 Shore C of the core surface hardness;
- wherein the geometric center hardness is about 64 Shore C to about 85 Shore C, and the core surface hardness is greater than 85 Shore C and harder than the geometric center hardness by about 5 to 22 Shore C to define a medium positive hardness gradient.
A golf ball comprising:
- a core comprising an inner core layer and an outer core layer, the inner core layer having a geometric center hardness of 66 to 80 Shore C and a surface hardness of 65 to 80 Shore C and being 0 to 5 Shore C harder than the center hardness to define a shallow positive hardness gradient;
- an outer cover layer having a Vicker's hardness of about 0.18 to 0.40 as measured on the ball at 0.49 N with a 10-s hold time;
- and
- an inner cover layer comprising an ionomer and being disposed between the core and the outer cover layer;
- wherein the outer core layer has a surface hardness of 86 to 96 Shore C and is harder than the geometric center by about 10 to 20 Shore C to define a positive hardness gradient.
A golf ball comprising:
- a core comprising an inner core layer and an outer core layer, the inner core layer having a geometric center hardness of about 66 to 82 Shore C and a surface hardness of 62 to 78 Shore C and being softer than the center hardness to define a negative hardness gradient;
- an outer cover layer comprising a polyurea, a polyurethane, or a hybrid thereof, the outer cover layer having a Vicker's hardness of about 0.18 to 0.40 as measured on the ball at 0.49 N with a 10-s hold time;
- and
- an inner cover layer comprising ionomer and being disposed between the core and the outer cover layer;
- wherein the outer core layer comprises a stiffening thermoplastic polymer, has a surface hardness of 86 to 96 Shore C, and is harder than the geometric center by about 10 to 20 Shore C to define a positive hardness gradient.
Dependencies are inferred from the claim text.