Golf ball

Abstract

A golf ball is provided that has a hard sphere core or layer that exhibits a controlled vibrational response. The vibrational response may be controlled by tailoring the stiffness or damping of the sphere with at least one element, such as a groove(s) or any other type of indentation in the hard sphere core. The groove (or grooves) serves to locally reduce the wall thickness of the hollow metal sphere core, thereby reducing the stiffness of the core by allowing larger deformations under a load without significantly reducing the total mass of the core. This results in a golf ball that is legal for play and capable of drive distances essentially equivalent to those of currently available high performance golf balls, but that also maintains a high moment of inertia, allowing less hooks and slices during play.

1 . A golf ball comprising: 
 a cover layer having an outer surface defining a dimpled pattern and an inner surface defining with the outer surface a cover thickness; and    a non-perforated hard sphere layer or core disposed within the cover layer, the hard sphere having an outer surface and an inner surface together with the outer surface defining a sphere thickness, wherein the hard sphere comprises at least one feature for controlling a vibrational response of the hard sphere.    
   
   
       2 . A golf ball according to  claim 1 , wherein the at least one feature for controlling the vibrational response of the hard sphere comprises at least one indentation for controlling a stiffness of the hard sphere.  
   
   
       3 . A golf ball according to  claim 1 , wherein the at least one indentation comprises a groove.  
   
   
       4 . A golf ball according to  claim 3 , wherein at least one of the outer sphere surface individually, the inner sphere surface individually, and both the outer sphere surface and the inner sphere surface further comprises a plurality of grooves.  
   
   
       5 . A golf ball according to  claim 4 , wherein the plurality of grooves further comprise a plurality of regularly spaced horizontal grooves and a plurality of regularly spaced vertical grooves, the plurality of vertical grooves being essentially perpendicular to the plurality of horizontal grooves.  
   
   
       6 . A golf ball according to  claim 4 , wherein the plurality of grooves further comprise a plurality of regularly spaced angled grooves that intersect a plurality of regularly spaced vertical grooves and a plurality of horizontal grooves.  
   
   
       7 . A golf ball according to  claim 3 , wherein at least one of the outer sphere surface individually, the inner sphere surface individually, and both the outer sphere surface and the inner sphere surface further comprises a plurality of regularly spaced grooves.  
   
   
       8 . A golf ball according to  claim 3 , wherein the groove defines a groove width and a groove depth, wherein the groove width is between about 1 nm to about 5 mm and the groove depth is between about 1 nm and about 5 mm.  
   
   
       9 . A golf ball according to  claim 1 , further comprising a resilient intermediate layer disposed between the hard sphere and the cover.  
   
   
       10 . A golf ball according to  claim 1 , wherein the hard sphere is a metal sphere of a metal selected from the group consisting of titanium and titanium alloys.  
   
   
       11 . A golf ball according to  claim 1 , wherein the at least one feature for controlling the vibrational response of the hard sphere comprises a plurality of indentations disposed randomly on at least one of the outer sphere surface and the inner sphere surface.  
   
   
       12 . A golf ball according to  claim 1 , wherein the thickness of the hard sphere core is between about 0.5 mm to about 6.4 mm.  
   
   
       13 . A golf ball according to  claim 1 , wherein the hard sphere is a hollow core.  
   
   
       14 . A golf ball according to  claim 13 , wherein the hollow sphere comprises a material disposed within the hollow sphere to at least one of dampen impact vibrations and prestress the hollow sphere.  
   
   
       15 . A golf ball according to  claim 1 , further comprising a resilient intermediate layer disposed between the hard sphere and the cover to prestress the hard sphere.  
   
   
       16 . A golf ball comprising: 
 a cover layer having an outer surface defining a dimpled pattern and an inner surface defining with the outer surface a cover thickness;    a hard sphere layer or core disposed within the cover layer, the hard sphere having an outer surface and an inner surface together with the outer surface defining a sphere thickness, wherein the hard sphere comprises at least one feature for controlling a vibrational response of the hard sphere; and    a resilient intermediate layer disposed between the hard sphere and the cover.    
   
   
       17 . A golf ball comprising: 
 a cover layer having an outer surface defining a dimpled pattern and an inner surface defining with the outer surface a cover thickness;    a metal sphere layer or core disposed within the cover layer, the metal sphere having an outer surface and an inner surface together with the outer surface defining a sphere thickness, wherein the metal sphere comprises at least one indentation for reducing a stiffness of the metal sphere; and    a resilient intermediate layer disposed between the metal sphere and the cover.    
   
   
       18 . A metal sphere core for use in a modern golf ball, the metal sphere core having an outer surface and an inner surface, together defining a core thickness, wherein the outer core surface individually, the inner core surface individually, or both the outer core surface and the inner core surface have at least one grove for controlling the stiffness of the metal sphere core.  
   
   
       19 . A metal sphere core according to  claim 18 , comprising a plurality of grooves, and wherein the outer core surface individually, the inner core surface individually, or both the outer core surface and the inner core surface comprise the plurality of grooves.  
   
   
       20 . A metal sphere core according to  claim 18 , comprising a plurality of grooves, and wherein the outer core surface individually, the inner core surface individually, or both the outer core surface and the inner core surface comprise the plurality of regularly spaced grooves.  
   
   
       21 . A metal sphere core according to  claim 18 , comprising a plurality of grooves, and wherein the outer core surface individually, the inner core surface individually, or both the outer core surface and the inner core surface includes a plurality of regularly spaced angled grooves that intersect the plurality of regularly spaced vertical grooves and the plurality of horizontal grooves.  
   
   
       22 . A metal sphere core according to  claim 18 , wherein the metal is selected from the group consisting of titanium and titanium alloys.  
   
   
       23 . A method of constructing a metal sphere core with controlled stiffness for use in a modern golf ball, the metal sphere core having an outer surface and an inner surface defining with the outer surface a core thickness, the method comprising: 
 forming at least one indentation in the outer core surface individually, the inner core surface individually, or both the outer core surface and the inner core surface for controlling the stiffness of the metal sphere core.    
   
   
       24 . A method for constructing a golf ball comprising forming an intermediate layer over a hard sphere layer or core, and forming a cover layer having an outer surface defining a dimpled pattern over the intermediate layer, wherein at least one of the cover layer, intermediate layer, and sphere layer or core comprise at least one of a material selected to achieve a desired vibrational response from the ball and a property associated with a shape, size, and damping of the sphere or layer to achieve the desired vibrational response from the ball.  
   
   
       25 . A method for constructing a golf ball according to  claim 24 , wherein a plurality of the cover layer, intermediate layer, and sphere layer or core, comprise a material set tailored to achieve the desired vibrational response.