Golf balls and methods of manufacturing the same
AssigneeCallaway Golf Company
InventorsPijush K. Dewanjee, David L. Felker, Gary G. Marshall
Life of this patent
Estimating the term…
Abstract
A golf ball made by a process that prevents the cover from cracking due to thermal expansion of the core during the cover formation process. The method includes the forming a core. One or more optional boundary layers can be applied to the surface of the core. The core and any boundary layers are pre-heated such that the core and any boundary layer undergo volumetric thermal expansion. After the pre-heating, the cover of the ball is formed over the core and any boundary layer. The method of the present invention also decreases cover molding cycle times for golf balls.
Claims3
A golf ball having reduced susceptibility of cracking of a cover, the golf ball produced in accordance with the method comprising:
- forming a golf ball precursor product having a first volume, the golf ball precursor product comprising a core and a boundary layer, the core comprising a polybutadiene material, the core having a diameter ranging from 1.35 inches to 1.64 inches, the core having a mass ranging from 32 grams to 40 grams, the core having a PGA compression ranging from 55 to 70, the boundary layer comprising a blend of ionomer materials, the boundary layer having a thickness ranging from 0.025 inch to 0.075 inch;
- heating the golf ball precursor product at a temperature ranging from 120° F. to 175° F. and for at least one hour to achieve a volumetric thermal expansion of the golf ball precursor product of at least 1.2% the golf ball precursor product increasing from the first volume to a heated volume;
- and
- applying a cover over the golf ball precursor product with the heated volume, the cover applied through an exothermic reaction, the cover comprising a thermoset material with a resin selected from the group consisting of diallyl pthalates and diallyl iso pthalates.
A golf ball having reduced susceptibility of cracking of a cover, the golf ball produced in accordance with the method comprising:
- forming a core comprising a polybutadiene material, the core having a diameter ranging 1.35 inches to 1.64 inches, a mass ranging from 32 grams to 40 grams, and a PGA compression ranging from 55 to 70;
- forming a boundary layer over the core, the boundary layer composed of a blend of ionomer materials, the boundary layer having thickness ranging from 0.025 inch to 0.075 inch, the boundary layer and core having a first volume;
- microwave heating the boundary layer and core at a power of 700 Watts for two minutes to achieve at least a 1.2% volumetric thermal expansion of the boundary layer and core to a heated volume;
- and
- casting a polyurethane cover over the golf ball precursor product with the heated volume, the polyurethane cover applied through an exothermic reaction;
- wherein the golf ball has a PGA compression ranging from 103 to 110.
A golf ball having reduced susceptibility of cracking of a cover, the golf ball produced in accordance with the method comprising:
- compression molding a core comprising polybutadiene material, the core having a diameter ranging from 1.35 inches to 1.64 inches, a mass ranging from 32 grams to 40 grams, and a PGA compression ranging from 55 to 70;
- injection molding a boundary layer composed of an ionomer blend material around the core to form a golf ball precursor product, the boundary layer having a thickness ranging from 0.025 inch to 0.075 inch, the golf ball precursor product having a diameter ranging from 1.630 inches to 1.644 inches;
- heating the golf ball precursor product to cause volumetric thermal expansion of the golf ball precursor product to create a thermally expanded golf ball precursor product having at least a 1.29% volume increase of the golf ball precursor product;
- and
- applying a thermosetting polyurethane cover to the thermally expanded golf ball precursor product through an exothermic reaction involving a polyurethane prepolymer and a curing agent;
- wherein the golf ball has a PGA compression ranging from 103 to 110.
Dependencies are inferred from the claim text.