Patent ID: 7270615

Claim:
A golf ball which comprises a spherical core, a mid layer positioned outside of the core, a reinforcing layer positioned outside of the mid layer and a cover positioned outside of the reinforcing layer, wherein the principal component of the base polymer of said mid layer is an ionomer resin, said mid layer having a hardness Hm as measured with a Shore D type hardness scale of equal to or greater than 55, the principal component of the base polymer of said cover is a thermoplastic polyurethane elastomer, said cover having a nominal thickness Tc of equal to or less than 0.6 mm, said cover having a hardness Hc as measured with a Shore D type hardness scale of equal to or less than 54, the ratio (Tr/Tc) of the thickness Tr of said reinforcing layer to the nominal thickness Tc of said cover is 0.005 or greater and 3.0 or less, said goff ball comprising dimples having a depth Dp on the surface thereof, and the thickness Td of the cover immediately below the deepest site of one or more of the dimples is greater than (Tc−Dp).