Golf ball incorporating an innermost hollow portion

Abstract

Golf ball incorporating a hollow innermost portion that is spherical or aspherical, and a shell layer that is at least partially non-continuous, having a plurality of hollow spaces therein that extend from the inner surface to an outer surface of the shell layer and are symmetrically spaced within the shell layer, wherein the non-continuous shell layer has a first hardness gradient from shell layer inner surface to outer surface of up to about 7 Shore C. An outer core layer has a second hardness gradient and is formed about the outer surface and within the plurality of hollow spaces. The outer core layer has a second inner surface having a second inner surface hardness that differs from the inner surface hardness. Thus, the second inner surface hardness and inner surface hardness may alternate symmetrically and circumferentially about the innermost hollow portion.

What is claimed is: 
     
         1 . A golf ball comprising:
 a hollow core comprising: an innermost spherical hollow portion having a diameter of about 0.15 inches to about 1.1 inches; surrounded by a shell layer formed from a thermoplastic composition; and at least one outer core layer formed from a thermoset composition;
 wherein the shell layer is at least partially non-continuous, having a plurality of hollow spaces therein that extend from an inner surface to an outer surface of the shell layer and are symmetrically spaced within the shell layer; and 
 wherein the inner surface has an inner surface hardness and the outer surface has an outer surface hardness greater than the inner surface hardness by up to about 7 Shore C to define a first hardness gradient; and 
 wherein the outer core layer has a second hardness gradient and is formed about the outer surface and within the plurality of hollow spaces; and 
   at least one cover layer disposed about the core.   
     
     
         2 . The golf ball of  claim 1 , wherein the outer core layer has a second inner surface having a second inner surface hardness that differs from the inner surface hardness. 
     
     
         3 . The golf ball of  claim 1 , wherein the first hardness gradient is about 1 to 5 Shore C. 
     
     
         4 . The golf ball of  claim 1 , wherein the shell layer is perforated. 
     
     
         5 . The golf ball of  claim 1 , wherein the shell layer is a screen or a lattice. 
     
     
         6 . The golf ball of  claim 1 , wherein the second hardness gradient is a negative hardness gradient of about 3 to 25 Shore C. 
     
     
         7 . The golf ball of  claim 1 , wherein the second hardness gradient is a positive hardness gradient of about 3 to 25 Shore C. 
     
     
         8 . The golf ball of  claim 1 , wherein the cover comprises an inner cover layer disposed about the outer core layer and comprising an ionomeric material and having a first hardness; and
 an outer cover layer disposed about the inner cover layer and comprising a polyurea or a polyurethane and having a second hardness less than the first.   
     
     
         9 . A golf ball comprising:
 a core comprising:
 an innermost aspherical hollow portion having a volume V ahp ; 
 surrounded by a shell layer that is formed from a thermoplastic composition and has an inner surface comprising a plurality of symmetrically spaced extensions that border and define a shape of the innermost aspherical hollow portion;
 wherein the plurality of extensions and innermost aspherical hollow portion, combined, form a phantom sphere having a diameter of from about 0.15 inches to about 1.1 inches; and 
 wherein the plurality of extensions have a combined total volume E TV  such that V ahp ≧E TV >0.20 (E TV +V ahp ); and 
 wherein the shell layer is at least partially non-continuous, having a plurality of hollow spaces therein that extend from the inner surface to an outer surface of the shell layer and are symmetrically spaced within the shell layer; and 
 
 at least one outer core layer that is formed about the outer surface; 
 wherein the inner surface has an inner surface hardness and the outer surface has an outer surface hardness greater than the inner surface hardness by up to about 7 Shore C to define a first hardness gradient; and 
 wherein the outer core layer has a second hardness gradient; and 
   at least one cover layer disposed about the outer core layer.   
     
     
         10 . The golf ball of  claim 9 , wherein the aspherical hollow portion has a shape that is axially symmetric. 
     
     
         11 . The golf ball of  claim 10 , wherein the aspherical hollow portion is at least one of non-spherical or irregularly-shaped. 
     
     
         12 . The golf ball of  claim 9 , wherein the plurality of extensions and innermost aspherical hollow portion, combined, form a spherical phantom sphere having a diameter of from about 0.30 inches to about 0.90 inches. 
     
     
         13 . The golf ball of  claim 9 , wherein the outer core layer has a second inner surface having a second inner surface hardness that differs from the inner surface hardness. 
     
     
         14 . The golf ball of  claim 9 , wherein the first hardness gradient is about 1 to 5 Shore C. 
     
     
         15 . The golf ball of  claim 9 , wherein the shell layer is a screen or a lattice. 
     
     
         16 . The golf ball of  claim 9 , wherein the at least one cover layer comprises an inner cover layer disposed about the outer core layer, and an outer cover layer disposed about the inner cover layer, wherein the inner cover layer comprises an ionomeric material and has a first hardness and the outer cover layer comprises a polyurea or a polyurethane and has a second hardness less than the first. 
     
     
         17 . The golf ball of  claim 9 , wherein the innermost aspherical hollow portion, shell layer and outer core layer, combined, have an outer diameter of from about 0.75 inches to about 1.62 inches. 
     
     
         18 . The golf ball of  claim 9 , wherein the second hardness gradient is a negative hardness gradient of about 3 to 25 Shore C. 
     
     
         19 . The golf ball of  claim 9 , wherein the second hardness gradient is a positive hardness gradient of about 3 to 25 Shore C. 
     
     
         20 . The golf ball of  claim 9 , wherein the outer core layer is formed from a thermoset composition. 
     
     
         21 . The golf ball of  claim 9 , wherein at least one outer core layer is formed from a thermoplastic composition. 
     
     
         22 . A golf ball comprising:
 a core comprising:
 a shell layer that is formed from a thermoplastic composition and has an inner surface comprising a plurality of symmetrically spaced extensions that border and define a shape of an innermost aspherical hollow portion;
 wherein the innermost aspherical hollow portion comprise from about 2% to about 30% of a total volume of the golf ball; and 
 wherein the shell layer is at least partially non-continuous, having a plurality of hollow spaces therein that extend from the inner surface to an outer surface of the shell layer and are symmetrically spaced within in the shell layer; and 
 
 at least one outer core layer that is formed about the outer surface; 
 wherein the inner surface has an inner surface hardness and the outer surface has an outer surface hardness greater than the inner surface hardness by up to about 7 Shore C to define a first hardness gradient; and 
 wherein the outer core layer has a second hardness gradient; and 
   at least one cover layer disposed about the core.   
     
     
         23 . The golf ball of  claim 22 , wherein the innermost aspherical hollow portion has a shape that is axially symmetric. 
     
     
         24 . The golf ball of  claim 23 , wherein the innermost aspherical hollow portion is at least one of non-spherical or irregularly-shaped. 
     
     
         25 . The golf ball of  claim 22 , wherein the plurality of extensions and innermost aspherical hollow portion, combined, form a phantom sphere having a diameter of from about 0.15 inches to about 1.1 inches. 
     
     
         26 . The golf ball of  claim 22 , wherein the outer core layer has a second inner surface having a second inner surface hardness that differs from the inner surface hardness. 
     
     
         27 . The golf ball of  claim 22 , wherein the first hardness gradient is about 1 to 5 Shore C. 
     
     
         28 . The golf ball of  claim 22 , wherein the shell layer is perforated. 
     
     
         29 . The golf ball of  claim 22 , wherein the shell layer is a screen or a lattice. 
     
     
         30 . The golf ball of  claim 22 , wherein the at least one cover layer comprises an inner cover layer disposed about the outer core layer, and an outer cover layer disposed about the inner cover layer, wherein the inner cover layer comprises an ionomeric material and has a first hardness, and the outer cover layer comprises a polyurea or a polyurethane and has a second hardness less than the first. 
     
     
         31 . The golf ball of  claim 22 , wherein the innermost aspherical hollow portion, shell layer and outer core layer, combined, have an outer diameter of from about 0.75 inches to about 1.62 inches. 
     
     
         32 . The golf ball of  claim 22 , wherein the second hardness gradient is a negative hardness gradient of about 3 to 25 Shore C. 
     
     
         33 . The golf ball of  claim 22 , wherein the second hardness gradient is a positive hardness gradient of about 3 to 25 Shore C. 
     
     
         34 . The golf ball of  claim 22 , wherein at least one outer core layer is formed from a thermoset composition. 
     
     
         35 . The golf ball of  claim 22 , wherein at least one outer core layer is formed from a thermoplastic composition.