Dual core golf ball having negative-hardness-gradient thermoplastic inner core and steep negative-hardness-gradient outer core layer
US7762910B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 2008 |
| Grant date | Jul 27, 2010 |
| Priority date | — |
| Expiry date | Mar 26, 2029 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA63B37/0058
- WIPO fieldFurniture, games
- WIPO sectorOther fields
Abstract
A golf ball comprising a thermoplastic inner core layer that has a geometric center hardness greater than its surface hardness to define a first “negative” hardness gradient. An outer core layer is disposed about the inner core and is formed from a substantially homogenous thermoset composition, typically rubber, and has an inner surface hardness greater than its outer surface hardness to also define a “negative” hardness gradient. An inner cover layer is disposed about the outer core layer and an outer cover layer is disposed about the inner cover layer. The “negative” hardness gradient of the inner core is typically −1 to −5 Shore C and the “negative” hardness gradient of the core layer is typically at least −7 Shore C. The difference between the inner core surface hardness and the outer core inner surface hardness, Δh, should be at least −3 Shore C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.