Multi-piece solid golf ball
US7329194B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 2006 |
| Grant date | Feb 12, 2008 |
| Priority date | — |
| Expiry date | Dec 27, 2026 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA63B37/0031
- WIPO fieldFurniture, games
- WIPO sectorOther fields
Abstract
The invention provides a multi-piece solid golf ball comprising a core, an envelope layer encasing the core, an intermediate layer encasing the envelope layer, and a cover which encases the intermediate layer and has formed on a surface thereof a plurality of dimples. The core is formed primarily of a rubber material, has a diameter of at least 31 mm, and has a hardness which gradually increases from a center to a surface thereof, the hardness difference in JIS-C hardness units between the core center and the core surface being at least 15 and, letting (I) be the average value for cross-sectional hardnesses at a position 15 mm from the core center and at the core center and letting (II) be the cross-sectional hardness at a position 7.5 mm from the core center, the hardness difference (I)−(II) therebetween in JIS-C units being not more than ±2. The envelope layer and the intermediate layer are each formed primarily of the same or different resin materials. The cover is formed primarily of a thermoplastic resin or a thermoplastic elastomer. The envelope layer, intermediate layer and cover have thicknesses which satisfy the relationship cover thickness<intermediate layer thickness<env…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.