Golf ball

Abstract

The present invention is a golf ball with a spherical core and a cover with one or more than two layers which covers the core, wherein the core includes two layers including an inner core having a spherical shape with an area formed in the center thereof, and an outer core covering the inner core, wherein value A is equal to or larger than 10.5 and value C is equal to or smaller than 3.7, wherein the value A is the deformation amount (mm) of the ball when the initial load is 98 N (10 kgf) and the ending load is 5880 N (600 kgf), and the value C is the deformation amount (mm) of the ball when the initial load is 98 N (10 kgf) and the ending load is 1275 N (130 kgf). The area is filled with at least one substance being different from the material of the inner core.

What is claimed is: 
     
         1 . A golf ball comprising:
 a spherical core; and   a cover with one or more than two layers covering the core, wherein   the core including two layers, one of which is an inner core being spherical and having an area in the center thereof, and the other of which is an outer core covering the inner core, the area being filled with at least one substance being different from a material of the inner core,   value A is larger than or equal to 10.5,   value C is smaller than or equal to 3.7,   the value A is a deformation amount (mm) of the golf ball when an initial load is 98 N (10 kgf) and an ending load is 5880 N (600 kgf), and   the value C is a deformation amount (mm) of the golf ball when an initial load is 98 N (10 kgf) and an ending load is 1275 N (130 kgf).   
     
     
         2 . The golf ball according to  claim 1 , wherein
 at least one substance being selected from a group consisting air, water, polyvinyl alcoholic (PVA) gel, cellulosic gel, oil state fluid, solid paraffin, and a jelly state food is filled in the area of the inner core.   
     
     
         3 . The golf ball according to  claim 1 , wherein
 the area of the inner core is a spherical space having a diameter between 5 and 18 mm.   
     
     
         4 . The golf ball according to  claim 1 , wherein
 an outer diameter of the inner core is between 15 and 25 mm.   
     
     
         5 . The golf ball according to  claim 1 , wherein
 a diameter of the core is between 34 and 40 mm.   
     
     
         6 . The golf ball according to  claim 1 , wherein
 surface hardness (S) of the inner core is between 30 and 90 in HS-A Hardness.   
     
     
         7 . The golf ball according to  claim 1 , wherein
 the cover covers the core with two layers,   the two layers are, from inside, an intermediate layer, and an outer most layer.   
     
     
         8 . The golf ball according to  claim 1 , wherein
 the cover covers the core with three layers,   the three layers are, from inside, a surrounding layer, an intermediate layer, and an outermost layer.   
     
     
         9 . The golf ball according to  claim 8 , wherein
 material hardness (Shore D Hardness) of the outer most layer is larger than material hardness of the surrounding layer.