US2025269244A1PendingUtilityA1

Multi-piece solid golf ball

Assignee: BRIDGESTONE SPORTS CO LTDPriority: Mar 8, 2023Filed: May 14, 2025Published: Aug 28, 2025
Est. expiryMar 8, 2043(~16.6 yrs left)· nominal 20-yr term from priority
A63B 37/0063A63B 37/0065A63B 37/0089A63B 37/0096A63B 37/009A63B 37/0018A63B 37/0083A63B 37/0068A63B 37/0067A63B 37/0077A63B 37/0087A63B 37/0084A63B 37/00922A63B 37/0075A63B 37/00215A63B 37/0017
64
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Claims

Abstract

Provided is a golf ball including a core, an intermediate layer, and a cover. A relationship between surface hardnesses of an intermediate layer-encased sphere and the ball satisfies a predetermined relational expression. With a ball initial velocity and a deflection under a predetermined load applied to the ball optimized, and letting a value of (initial velocity of core×weight of core) be Ciw, a value of [(initial velocity of intermediate layer-encased sphere−initial velocity of core)×(weight of intermediate layer-encased sphere−weight of core)] be Miw, and a value of [(initial velocity of ball−initial velocity of intermediate layer-encased sphere)×(weight of ball−weight of intermediate layer-encased sphere)] be CViw, the following condition is satisfied: 2500 ≤ Ciw + Miw + CViw ≤ 2650 , wherein a total volume of the dimples is from 306 to 363 mm 3 .

Claims

exact text as granted — not AI-modified
1 . A multi-piece solid golf ball comprising a core, an intermediate layer, and a cover, a large number of dimples being formed on an outside surface of the cover, wherein a relationship between a surface hardness of an intermediate layer-encased sphere and a surface hardness of the ball satisfies the following condition:
   (surface hardness of ball)<(surface hardness of intermediate layer-encased sphere)   (where the surface hardnesses mean Shore C hardnesses),   wherein when an initial velocity of the ball is 76.5 to 77.724 m/s, a deflection is at least 2.7 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), and a value of (initial velocity of core×weight of core) is denoted by Ciw, a value of [(initial velocity of intermediate layer-encased sphere−initial velocity of core)×(weight of intermediate layer-encased sphere−weight of core)] is denoted by Miw, and a value of [(initial velocity of ball−initial velocity of intermediate layer-encased sphere)×(weight of ball−weight of intermediate layer-encased sphere)] is denoted by CViw, the following condition is satisfied:   
       
         
           
             
               
                 2500 
                 ≤ 
                 
                   Ciw 
                   + 
                   Miw 
                   + 
                   CViw 
                 
                 ≤ 
                 2560 
               
               , 
             
           
         
         wherein a total volume of the dimples is from 306 to 363 mm 3 . 
       
     
     
         2 . The multi-piece solid golf ball according to  claim 1 , wherein when a ratio CL1/CD1 of a lift coefficient CL1 at a Reynolds number of 218000 and a spin rate of 2800 rpm to a drag coefficient CD1 is denoted by A1, and a ratio CL2/CD2 of a lift coefficient CL2 at a Reynolds number of 158000 and a spin rate of 3100 rpm to a drag coefficient CD2 is denoted by A2, the following two conditions are satisfied: 
       
         
           
             
               0.59 
               ≤ 
               
                 A 
                 ⁢ 
                 1 
               
               ≤ 
               
                 0.655 
                     
                 and 
                 ⁢ 
                     
                 A 
                 ⁢ 
                 2 
               
               ≥ 
               
                 0.695 
                 . 
               
             
           
         
       
     
     
         3 . The multi-piece solid golf ball according to  claim 1 , wherein when an initial velocity of the core is denoted by Vc (m/s), and a deflection is denoted by C (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), the following condition is satisfied: 
       
         
           
             
               15 
               ≤ 
               
                 Vc 
                 / 
                 C 
               
               ≤ 
               25. 
             
           
         
       
     
     
         4 . The multi-piece solid golf ball according to  claim 1 , wherein a relationship between a surface hardness of the core and the surface hardness of the intermediate layer-encased sphere satisfies the following condition:
   (surface hardness of intermediate layer-encased sphere)≥(surface hardness of core)
   (where the hardnesses mean Shore C hardnesses).   
     
     
         5 . The multi-piece solid golf ball according to  claim 1 , wherein when each sphere of the core, the intermediate layer-encased sphere, and the ball is compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) and deflections (mm) are denoted by C (mm), M (mm), and B (mm) respectively, the following two conditions are satisfied: 
       
         
           
             
               
                 
                   
                     1. 
                     ≤ 
                     
                       C 
                       - 
                       B 
                     
                     ≤ 
                     1.5 
                   
                 
               
               
                 
                   
                     0.65 
                     ≤ 
                     
                       C 
                       - 
                       M 
                     
                     ≤ 
                     
                       1.15 
                       . 
                     
                   
                 
               
             
           
         
       
     
     
         6 . The multi-piece solid golf ball according to  claim 1 , wherein when a deflection (mm) is denoted by C (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), the following condition is satisfied: 
       
         
           
             
               400 
               ≤ 
               
                 Ciw 
                 / 
                 C 
               
               ≤ 
               850. 
             
           
         
       
     
     
         7 . The multi-piece solid golf ball according to  claim 1 , wherein the core has a hardness profile in which, letting the Shore C hardness at a core center be Cc, the Shore C hardness at a position 4 mm outward from the core center be Cc+4, the Shore C hardness at a midpoint M between the core center and a core surface be Cm, the Shore C hardness at a position 4 mm inward from the midpoint M be Cm−4, the Shore C hardness at a position 4 mm outward from the midpoint M be Cm+4, the Shore C hardness at the core surface be Cs, and the Shore C hardness at a position 4 mm inward from the core surface be Cs−4, and defining surface areas A to D as follows: 
       
         
           
             
               
                 
                   
                     surface 
                     ⁢ 
                         
                     area 
                     ⁢ 
                         
                     A 
                     : 
                     1 
                     / 
                     2 
                     × 
                     4 
                     × 
                     
                       ( 
                       
                         Cc 
                         + 
                         4 
                         - 
                         Cc 
                       
                       ) 
                     
                   
                 
               
               
                 
                   
                     surface 
                     ⁢ 
                         
                     area 
                     ⁢ 
                         
                     B 
                     : 
                     1 
                     / 
                     2 
                     × 
                     4 
                     × 
                     
                       ( 
                       
                         Cm 
                         - 
                         Cm 
                         - 
                         4 
                       
                       ) 
                     
                   
                 
               
               
                 
                   
                     surface 
                     ⁢ 
                         
                     area 
                     ⁢ 
                     
                         
                          
                     
                     ⁢ 
                     C 
                     : 
                     1 
                     / 
                     2 
                     × 
                     4 
                     × 
                     
                       ( 
                       
                         Cm 
                         + 
                         4 
                         - 
                         Cm 
                       
                       ) 
                     
                   
                 
               
               
                 
                   
                     surface 
                     ⁢ 
                         
                     area 
                     ⁢ 
                         
                     D 
                     : 
                     1 
                     / 
                     2 
                     × 
                     4 
                     × 
                     
                       ( 
                       
                         Cs 
                         - 
                         Cs 
                         - 
                         4 
                       
                       ) 
                     
                   
                 
               
             
           
         
         the following condition is satisfied: 
       
       
         
           
             
               
                 
                   ( 
                   
                     
                       surface 
                       ⁢ 
                           
                       area 
                       ⁢ 
                           
                       C 
                     
                     + 
                     
                       surface 
                       ⁢ 
                           
                       area 
                       ⁢ 
                           
                       D 
                     
                   
                   ) 
                 
                 - 
                 
                   ( 
                   
                     
                       surface 
                       ⁢ 
                           
                       area 
                       ⁢ 
                           
                       A 
                     
                     + 
                     
                       surface 
                       ⁢ 
                           
                       area 
                       ⁢ 
                           
                       B 
                     
                   
                   ) 
                 
               
               ≥ 
               
                 2. 
                 . 
               
             
           
         
       
     
     
         8 . The multi-piece solid golf ball according to  claim 7 , wherein the core has a hardness profile in which the following condition is satisfied: 
       
         
           
             
               
                 ( 
                 
                   Cs 
                   - 
                   Cc 
                 
                 ) 
               
               ≥ 
               22. 
             
           
         
       
     
     
         9 . The multi-piece solid golf ball according to  claim 6 , wherein the core has a hardness profile in which the following condition is satisfied: 
       
         
           
             
               
                 
                   ( 
                   
                     Cs 
                     - 
                     Cc 
                   
                   ) 
                 
                 / 
                 
                   ( 
                   
                     Cm 
                     - 
                     Cc 
                   
                   ) 
                 
               
               ≥ 
               
                 3. 
                 . 
               
             
           
         
       
     
     
         10 . The multi-piece solid golf ball according to  claim 6 , wherein the core has a hardness profile in which the following condition is satisfied: 
       
         
           
             
               
                 
                   ( 
                   
                     
                       surface 
                       ⁢ 
                           
                       area 
                       ⁢ 
                           
                       C 
                     
                     + 
                     
                       surface 
                       ⁢ 
                           
                       area 
                       ⁢ 
                           
                       D 
                     
                   
                   ) 
                 
                 / 
                 
                   ( 
                   
                     
                       surface 
                       ⁢ 
                           
                       area 
                       ⁢ 
                           
                       A 
                     
                     + 
                     
                       surface 
                       ⁢ 
                           
                       area 
                       ⁢ 
                           
                       B 
                     
                   
                   ) 
                 
               
               ≥ 
               
                 2. 
                 . 
               
             
           
         
       
     
     
         11 . The multi-piece solid golf ball according to  claim 6 , wherein the core has a hardness profile in which the following condition is satisfied:
   surface area D>surface area C>surface area B.   
     
     
         12 . The multi-piece solid golf ball according to  claim 1 , wherein a volume occupancy ratio VR of the dimples is from 0.75 to 0.89%. 
     
     
         13 . The multi-piece solid golf ball according to  claim 1 , wherein a value of A2 is from 0.695 to 0.815.

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