US 12,134,010 B2
Multi-piece solid golf ball
Hideo Watanabe, Saitamaken (JP)
Assigned to BRIDGESTONE SPORTS CO., LTD., Tokyo (JP)
Filed by BRIDGESTONE SPORTS CO., LTD., Tokyo (JP)
Filed on Mar. 31, 2023, as Appl. No. 18/193,842.
Claims priority of application No. 2022-062202 (JP), filed on Apr. 4, 2022.
Prior Publication US 2023/0310947 A1, Oct. 5, 2023
Int. Cl. A63B 37/06 (2006.01); A63B 37/00 (2006.01)
CPC A63B 37/0039 (2013.01) [A63B 37/0033 (2013.01); A63B 37/0034 (2013.01); A63B 37/0043 (2013.01); A63B 37/0045 (2013.01); A63B 37/0046 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A multi-piece solid golf ball comprising a core, an envelope layer, an intermediate layer and a cover, wherein the core is formed of one or more layer of a rubber composition; the envelope layer, intermediate layer and cover are each formed of a single layer of resin material; the hardness relationship among the layers, in terms of Shore C hardness values, satisfies the following two conditions:
material hardness of cover>material hardness of intermediate layer, and
material hardness of envelope layer≥surface hardness of core;
the ball additionally satisfies the condition:
thickness (mm) of envelope layer×material hardness (Shore D hardness) of envelope layer≥thickness (mm) of cover×material hardness (Shore D hardness) of cover; and, letting C be the deflection of the core in millimeters when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) and B be the deflection of the ball in millimeters when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf), C-B has a value of 1.00 mm or more, and
the ball satisfies the condition:
0.80≤(E·vh+I·vh)/Core·vh≤2.00,
wherein Core vh is the value expressed as [core volume (mm3)×(Shore C hardness at core surface+Shore C hardness at core center)/2], E·vh is the value expressed as [volume (mm3) of envelope layer material portion×Shore C hardness of envelope layer material] and I·vh is the value expressed as [volume (mm3) of intermediate layer material portion×Shore C hardness of intermediate layer material].