Patent ID: 7445567

Claim:
A multi-piece solid golf ball comprising a core, an envelope layer which encases the core and comprises an inside layer and an outside layer, 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, wherein the core is formed primarily of a rubber material, the envelope layer, intermediate layer and cover are each formed primarily of the same or different resin materials; the envelope layer, intermediate layer and cover have thicknesses which satisfy the relationship: cover thickness<intermediate layer thickness<envelope layer total thickness; the envelope layer, intermediate layer and cover have material hardnesses (Durometer D hardness) which satisfy the relationship: hardness of envelope inside layer material<hardness of envelope outside layer material<hardness of intermediate layer material>hardness of cover material; the envelope outside layer material has a Durometer D hardness of at least 53; the surface hardness of the golf ball is made softer than the surface hardness of the intermediate layer by an amount within a Durometer D hardness range of 1 to 10; and the value V 0 obtained by dividing the spatial volume of each dimple below the flat plane circumscribed by the edge of that dimple by the volume of a cylinder whose base is the flat plane and whose height from the base to the maximum depth of the dimple is at least 0.35 but not more than 0.80.