Multi-layer golf ball

Abstract

A multi-layer golf ball includes a core, and intermediate layer, and a cover. The core has an outer surface that includes a plurality of protrusions extending from a spherical land portion. Each protrusion has a maximum height relative to the spherical land portion of between 0.15 mm and 2.0 mm. The intermediate layer surrounds the core and has a radially outward surface that is flush with the outer surface of the core. The cover layer surrounds the intermediate layer and defines an outermost portion of ball.

What is claimed is: 
     
         1 . A multi-layer golf ball comprising:
 a core having an outer surface that includes a plurality of protrusions extending radially outward from a spherical land portion;   an intermediate layer surrounding the core and having a radially outward surface that is bonded to the outer surface of the core across the entire outer surface;   a cover layer surrounding the intermediate layer and defining an outermost portion of ball; and   wherein each protrusion has a maximum height relative to the spherical land portion of between 0.15 mm and 2.0 mm.   
     
     
         2 . The golf ball of  claim 1 , wherein the plurality of protrusions includes between 50 and 80 protrusions that are symmetrically disposed about the core. 
     
     
         3 . The golf ball of  claim 1 , wherein the intermediate layer is bonded to the core through an adhesive layer. 
     
     
         4 . The golf ball of  claim 1 , wherein each protrusion has a maximum height relative to the spherical land portion of between 0.15 mm and 1.0 mm. 
     
     
         5 . The golf ball of  claim 1 , wherein each protrusion has a maximum height relative to the spherical land portion that is substantially the same. 
     
     
         6 . The golf ball of  claim 1 , wherein each protrusion has a circular outer profile that is defined by the intersection of the respective protrusion and the spherical land portion. 
     
     
         7 . The golf ball of  claim 6 , wherein the circular outer profile of each protrusion has a diameter of greater than 5 mm. 
     
     
         8 . The golf ball of  claim 1 , wherein each protrusion includes a central portion that is planar. 
     
     
         9 . The golf ball of  claim 1 , wherein the spherical land portion is aligned on a first sphere; and
 wherein each protrusion includes a central portion that is aligned on a second sphere; and   wherein the first sphere and the second sphere are concentric.   
     
     
         10 . The golf ball of  claim 1 , wherein the plurality of protrusions are uniform in dimension. 
     
     
         11 . The golf ball of  claim 1 , wherein each of the plurality of protrusions has a sidewall that includes a sloped portion at an angle of between about 40° and about 70° relative to a radial axis. 
     
     
         12 . The golf ball of  claim 11 , wherein each of the plurality of protrusions includes a radius of curvature that transitions from the sidewall of the protrusion to at least one of a central portion of the protrusion and an adjacent polygonal land portion; and
 wherein the radius of curvature is between about 0.25 mm and about 2.0 mm.   
     
     
         13 . The golf ball of  claim 1 , wherein each protrusion has a height measured in a radial direction relative to the spherical land portion, and a width measured at the spherical land portion; and
 wherein each protrusion has a width/height ratio of between 2 and 8.   
     
     
         14 . The golf ball of  claim 1 , wherein the spherical land portion of the core has a diameter of between 24 mm and 32 mm. 
     
     
         15 . The golf ball of  claim 14 , wherein the intermediate layer has a minimum radial thickness of between 4.0 mm and 9.0 mm. 
     
     
         16 . The golf ball of  claim 1 , wherein the intermediate layer is a first intermediate layer; and 
       further comprising a second intermediate layer disposed between the first intermediate layer and the cover layer. 
     
     
         17 . The golf ball of  claim 16  wherein the second intermediate layer and the cover layer have a total minimum radial thickness of up to about 2.5 mm. 
     
     
         18 . A multi-layer golf ball comprising:
 a core having an outer surface that includes a plurality of protrusions extending radially outward from a spherical land portion, the spherical land portion having a diameter between about 24 mm and about 32 mm;   an intermediate layer surrounding the core and having a radially inward surface that is bonded to the outer surface of the core across the entire outer surface, the intermediate layer having a minimum radial thickness of between about 4 mm and about 9 mm;   a cover layer surrounding the intermediate layer and defining an outermost portion of ball;   wherein the plurality of protrusions includes from about 50 to about 80 protrusions that are symmetrically disposed about the surface, each protrusion having a maximum height relative to the spherical land portion of between about 0.15 mm and about 2.0 mm.   
     
     
         19 . The golf ball of  claim 18 , wherein the intermediate layer is bonded to the core through an adhesive layer. 
     
     
         20 . The golf ball of  claim 18 , wherein each protrusion has a maximum height relative to the spherical land portion of between about 0.15 mm and about 1.0 mm. 
     
     
         21 . The golf ball of  claim 18 , wherein each protrusion has a circular outer profile that is defined by the intersection of the respective protrusion and the spherical land portion. 
     
     
         22 . The golf ball of  claim 21 , wherein the circular outer profile of each protrusion has a diameter of greater than 5 mm. 
     
     
         23 . The golf ball of  claim 18 , wherein each protrusion includes a central portion that is substantially planar. 
     
     
         24 . The golf ball of  claim 18 , wherein the spherical land portion is aligned on a first sphere; and
 wherein each protrusion includes a central portion that is aligned on a second sphere; and   wherein the first sphere and the second sphere are concentric.   
     
     
         25 . The golf ball of  claim 18 , wherein the intermediate layer is a first intermediate layer; and 
       further comprising a second intermediate layer disposed between the first intermediate layer and the cover layer. 
     
     
         26 . The golf ball of  claim 18 , wherein each of the plurality of protrusions has a sidewall that includes a sloped portion at an angle of between about 40° and about 70° relative to a radial axis. 
     
     
         27 . The golf ball of  claim 26 , wherein each of the plurality of protrusions includes a radius of curvature that transitions from the sidewall of the groove to at least one of a central portion of the protrusion and an adjacent polygonal land portion; and
 wherein the radius of curvature is between about 0.25 mm and about 2.0 mm.   
     
     
         28 . The golf ball of  claim 18 , wherein each protrusion has a maximum height relative to the spherical land portion, and a width measured at the spherical land portion; and
 wherein each protrusion has a width/height ratio of between 2 and 8.