US2025303238A1PendingUtilityA1

Golf ball

Assignee: BRIDGESTONE SPORTS CO LTDPriority: Mar 27, 2024Filed: Mar 18, 2025Published: Oct 2, 2025
Est. expiryMar 27, 2044(~17.7 yrs left)· nominal 20-yr term from priority
Inventors:Hideo Watanabe
A63B 37/0092A63B 37/0076A63B 37/0075A63B 37/0039A63B 37/0084A63B 37/0066A63B 37/0035A63B 37/0063A63B 37/00622A63B 37/00922A63B 37/0047
62
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0
Cited by
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References
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Claims

Abstract

A golf ball includes a core and a cover, in which the core is formed of a rubber composition in a single layer, the cover is formed of a resin composition, a hardness profile of the core has a specific cross-sectional hardness profile, and letting a deflection (mm) when the core is compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) be C (mm), a Shore C hardness at a core center be H0, and a Shore C hardness at a core surface be H100, the following condition is satisfied:C×(H100-H0)≥1⁢2⁢5.0.

Claims

exact text as granted — not AI-modified
1 . A golf ball comprising a core and a cover, the core being formed of a rubber composition in a single layer, and the cover being formed of a resin composition, wherein in a hardness profile of the core, letting a Shore C hardness at a core center be H 0 , a Shore C hardness at a position where a distance from the core center is 12.5% of a core radius be H 12.5 , a Shore C hardness at a position where the distance from the core center is 25% of the core radius be H 25 , a Shore C hardness at a position where the distance from the core center is 37.5% of the core radius be H 37.5 , a Shore C hardness at a position where the distance from the core center is 50% of the core radius be H 50 , a Shore C hardness at a position where the distance from the core center is 62.5% of the core radius be H 62.5 , a Shore C hardness at a position where the distance from the core center is 75% of the core radius be H 75 , a Shore C hardness at a position where the distance from the core center is 87.5% of the core radius be H 87.5 , and a shore C hardness at a core surface be H 100 , and defining differences in hardness between the respective positions as follows:
 A: H 100 −H 87.5      B: H 87.5 −H 75      C: H 75 −H 62.5      D: H 62.5 −H 50      E: H 50 −H 37.5      F: H 37.5 −H 25      G: H 25 −H 12.5      H: H 12.5 −H 0      the following two conditions (I) and (II) are satisfied:   
       
         
           
             
               
                 
                   
                     
                       ( 
                       
                         E 
                         + 
                         F 
                         + 
                         G 
                         + 
                         H 
                       
                       ) 
                     
                     < 
                     
                       ( 
                       
                         C 
                         + 
                         D 
                       
                       ) 
                     
                   
                 
                 
                   
                     ( 
                     I 
                     ) 
                   
                 
               
             
           
         
         
           
             
               
                 
                   
                     
                       ( 
                       
                         
                           H 
                           100 
                         
                         - 
                         
                           H 
                           0 
                         
                       
                       ) 
                     
                     ≥ 
                     
                       3 
                       ⁢ 
                       
                         0 
                         . 
                         0 
                       
                     
                   
                 
                 
                   
                     ( 
                     II 
                     ) 
                   
                 
               
             
           
         
         and letting a deflection (mm) when the core is compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) be C (mm), the following condition is satisfied: 
       
       
         
           
             
               
                 
                   
                     
                       C 
                       × 
                       
                         ( 
                         
                           
                             H 
                             100 
                           
                           - 
                           
                             H 
                             0 
                           
                         
                         ) 
                       
                     
                     ≥ 
                     
                       1 
                       ⁢ 
                       2 
                       ⁢ 
                       
                         5. 
                         . 
                       
                     
                   
                 
                 
                   
                     ( 
                     III 
                     ) 
                   
                 
               
             
           
         
       
     
     
         2 . The golf ball of  claim 1 , wherein the following condition (IV) is satisfied: 
       
         
           
             
               
                 
                   
                     
                       
                         ( 
                         
                           E 
                           + 
                           F 
                           + 
                           G 
                           + 
                           H 
                         
                         ) 
                       
                       < 
                       
                         ( 
                         
                           A 
                           + 
                           B 
                         
                         ) 
                       
                     
                     . 
                   
                 
                 
                   
                     ( 
                     IV 
                     ) 
                   
                 
               
             
           
         
       
     
     
         3 . The golf ball of  claim 1 , wherein the following condition (V) is satisfied: 
       
         
           
             
               
                 
                   
                     
                       
                         ( 
                         
                           E 
                           + 
                           F 
                           + 
                           G 
                           + 
                           H 
                         
                         ) 
                       
                       < 
                       
                         ( 
                         
                           C 
                           + 
                           D 
                         
                         ) 
                       
                       < 
                       
                         ( 
                         
                           A 
                           + 
                           B 
                         
                         ) 
                       
                     
                     . 
                   
                 
                 
                   
                     ( 
                     V 
                     ) 
                   
                 
               
             
           
         
       
     
     
         4 . The golf ball of  claim 1 , wherein the following condition (VI) is satisfied: 
       
         
           
             
               
                 
                   
                     
                       
                         { 
                         
                           
                             ( 
                             
                               C 
                               + 
                               D 
                             
                             ) 
                           
                           - 
                           
                             ( 
                             
                               E 
                               + 
                               F 
                               + 
                               G 
                               + 
                               H 
                             
                             ) 
                           
                         
                         } 
                       
                       ≥ 
                       
                         3 
                         . 
                         0 
                       
                     
                     . 
                   
                 
                 
                   
                     ( 
                     VI 
                     ) 
                   
                 
               
             
           
         
       
     
     
         5 . The golf ball of  claim 1 , wherein the following condition (VII) is satisfied: 
       
         
           
             
               
                 
                   
                     
                       { 
                       
                         
                           ( 
                           
                             
                               H 
                               100 
                             
                             - 
                             
                               H 
                               0 
                             
                           
                           ) 
                         
                         / 
                         
                           ( 
                           
                             
                               H 
                               
                                 5 
                                 ⁢ 
                                 0 
                               
                             
                             - 
                             
                               H 
                               0 
                             
                           
                           ) 
                         
                       
                       } 
                     
                     ≥ 
                     
                       5. 
                       . 
                     
                   
                 
                 
                   
                     ( 
                     VII 
                     ) 
                   
                 
               
             
           
         
       
     
     
         6 . The golf ball of  claim 1 , wherein the following condition (VIII) is satisfied: 
       
         
           
             
               
                 
                   
                     
                       { 
                       
                         
                           ( 
                           
                             
                               H 
                               87.5 
                             
                             - 
                             
                               H 
                               0 
                             
                           
                           ) 
                         
                         / 
                         
                           ( 
                           
                             
                               H 
                               
                                 5 
                                 ⁢ 
                                 0 
                               
                             
                             - 
                             
                               H 
                               0 
                             
                           
                           ) 
                         
                       
                       } 
                     
                     ≥ 
                     
                       3. 
                       . 
                     
                   
                 
                 
                   
                     ( 
                     VIII 
                     ) 
                   
                 
               
             
           
         
       
     
     
         7 . The golf ball of  claim 1 , wherein the core is formed of a rubber composition containing the following components (A) to (D):
 (A) a base rubber,   (B) an organic peroxide,   (C) water or a monocarboxylic acid metal salt,   (D) sulfur.   
     
     
         8 . The golf ball of  claim 7 , wherein a content ratio of the components (D) and (C) is from 0.005 to 0.100 in a weight ratio of (D)/(C). 
     
     
         9 . The golf ball of  claim 1 , wherein an intermediate layer is formed between the core and the cover. 
     
     
         10 . The golf ball of  claim 9 , wherein the intermediate layer contains an inorganic particulate filler. 
     
     
         11 . The golf ball of  claim 9 , wherein a specific gravity of the intermediate layer is at least 1.05. 
     
     
         12 . The golf ball of  claim 1 , wherein, letting a deflection (mm) when the ball is compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) be B (mm), the following two conditions are satisfied:
     B≥ 2.80       C - B≥ 1.00.   
     
     
         13 . The golf ball of  claim 9 , wherein a relationship between a core surface hardness, a surface hardness of a sphere (intermediate layer-encased sphere) in which the core is encased with the intermediate layer, and a surface hardness of a sphere (ball) in which the intermediate layer-encased sphere is encased with the cover satisfies the following condition:
   ball surface hardness<surface hardness of intermediate layer-encased sphere>core surface hardness   where the surface hardness of each sphere means Shore C hardness.   
     
     
         14 . The golf ball of  claim 9 , wherein a difference between a specific gravity of the cover and a specific gravity of the intermediate layer is not more than 0.15, and a difference between the specific gravity of the intermediate layer and a specific gravity of the core is not more than 0.15. 
     
     
         15 . The golf ball of  claim 9 , wherein a relationship between an initial velocity of the entire core, an initial velocity of a sphere (intermediate layer-encased sphere) in which the core is encased with the intermediate layer, and an initial velocity of a sphere (ball) in which the intermediate layer-encased sphere is encased with the cover satisfies the following two conditions: 
       
         
           
             
               
                 ( 
                 
                   initial 
                   ⁢ 
                       
                   velocity 
                   ⁢ 
                       
                   of 
                   ⁢ 
                       
                   ball 
                 
                 ) 
               
               < 
               
                 
                   ( 
                   
                     initial 
                     ⁢ 
                         
                     velocity 
                     ⁢ 
                         
                     of 
                     ⁢ 
                         
                     intermediate 
                     ⁢ 
                         
                     layer 
                     - 
                     encased 
                     ⁢ 
                         
                     sphere 
                   
                   ) 
                 
                     
                 0.65 
               
               ≤ 
               
                 
                   ( 
                   
                     initial 
                     ⁢ 
                         
                     velocity 
                     ⁢ 
                         
                     of 
                     ⁢ 
                         
                     intermediate 
                     ⁢ 
                         
                     layer 
                     - 
                     encased 
                     ⁢ 
                         
                     sphere 
                   
                   ) 
                 
                 - 
                 
                   ( 
                   
                     initial 
                     ⁢ 
                         
                     velocity 
                     ⁢ 
                         
                     of 
                     ⁢ 
                         
                     entire 
                     ⁢ 
                         
                     core 
                   
                   ) 
                 
               
               ≤ 
               
                 0.98 
                     
                 
                   
                     ( 
                     
                       m 
                       / 
                       s 
                     
                     ) 
                   
                   .

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