Patent ID: 8206245
Filing Date: 2012-06-26
Classification: A63B

Abstract:
1. A golf ball comprising a core, an envelope layer positioned outside the core, a mid layer positioned outside the envelope layer and a cover positioned outside the mid layer, wherein, a thickness Tm of the mid layer is less than 1.2 mm, a thickness Tc of the cover is less than 0.6 mm, the sum of the thickness Tm and the thickness Tc is equal to or less than 1.7 mm, a Shore D hardness Hc of the cover is less than 40, and the Shore D hardness Hs of the envelope layer, the Shore D hardness Hm of the mid layer, and the Shore D hardness He of the cover satisfy the following formula (2): wherein the base material of the cover is polyurethane; wherein the base material of the mid layer is polyurethane; wherein the base material of the envelope layer is ionomer resin; wherein a difference between the hardness Hs of the envelope layer and the hardness Hm of the mid layer is equal to or greater than 10 and equal to or less than 29; wherein a difference between the hardness Hs of the envelope layer and the hardness Hc of the cover is equal to or greater than 19 and equal to or less than 41; and wherein a difference between the hardness Hm of the mid layer and the hardness Hc of the cover is equal to or greater than 9 and equal to or less than 21.