# US 10,946,251 B2 · Multi-piece solid golf ball > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,946,251 B2 - Document ID: US10946251B2 - Status: Granted - Kind: B2 - Application number: 16/831,951 - Filed: 2020-03-27 - Published: 2020-08-06 - Granted: 2021-03-16 - Earliest claimed: 2014-12-17 - Assignees: Bridgestone Sports Co., Ltd. - Applicants: Bridgestone Sports Co., Ltd. - Inventors: Hideo Watanabe; Akira Kimura; Jun Shindo - Web page: https://patentgrep.com/patent/US10946251B2 ## CPC - A63B 37/0092: {Hardness distribution amongst different ball layers} - A63B 37/0031: {Hardness} - A63B 37/0033: {Thickness} - A63B 37/0045: {Thickness} - A63B 37/00621: {Centre hardness} - A63B 37/00622: {Surface hardness} - A63B 37/0063: {Hardness gradient} - A63B 37/0065: {Deflection or compression} - A63B 37/0068: {Initial velocity} - A63B 37/0084: {Initial velocity} - A63B 37/0039: {characterised by the material} - A63B 37/0075: {Three piece balls, i.e. cover, intermediate layer and core} - A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H) ## Abstract In a multi-piece solid golf ball having a core, a cover and an intermediate layer therebetween, the core, an intermediate layer-encased sphere and the ball have surface hardnesses which satisfy a specific relationship, and the intermediate layer and the cover have thicknesses which satisfy a specific relationship. Also, the core has a hardness profile in which the hardnesses at the core surface, core center, a position 5 mm from the core center, and a position midway between the surface and center of the core satisfy specific relationships. This golf ball, when used by mid- and high-level amateurs, enables the golfer to maintain an adequate distance on shots with a driver and achieve a good distance on iron shots, has a good spin performance on approach shots and has a good feel on impact. In addition, the ball has an excellent scuff resistance when struck with a grooved wedge. ## Claims ### Claim 1 A multi-piece solid golf ball comprising a core, a cover and an intermediate layer therebetween, wherein the core, a sphere composed of the core and the intermediate layer which peripherally encases the core (intermediate layer-encased sphere), and the ball have respective surface hardnesses, expressed in terms of Shore D hardness, which satisfy the relationship ball surface hardness≤surface hardness of intermediate layer-encased sphere≥core surface hardness; the thickness of the cover is not more than 1.2 mm, and the intermediate layer and the cover have respective thicknesses which satisfy the relationship (thickness of intermediate layer−thickness of cover)≥0; and the core has a hardness profile which, expressed in terms of JIS-C hardness, satisfies the following relationships: 5≥[hardness at a position 5 mm from core center (C5)−core center hardness (Cc)]>0, [core surface hardness (Cs)−core center hardness (Cc)]/[hardness at a position midway between core surface and core center (Cm)−core center hardness (Cc)]3.0, and 6≥[hardness at a position midway between core surface and core center (Cm)−core center hardness (Cc)]2. ### Claim 2 (depends on 1) The multi-piece solid golf ball of claim 1, wherein the [core surface hardness (Cs)−core center hardness (Cc)]/[hardness at a position 5 mm from core center (C5)−core center hardness (Cc)] value, is 4 or more. ### Claim 3 (depends on 1) The multi-piece solid golf ball of claim 1, wherein the (core surface hardness−ball surface hardness) value, expressed in terms of Shore D hardness, is in the range of −10 to 2. ### Claim 4 (depends on 1) The multi-piece solid golf ball of claim 1 which satisfies the relationship 0.7 mm≤E−B≤1.6 mm, wherein E is the deflection of the core when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) and B is the deflection of the ball when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf). ### Claim 5 (depends on 1) The multi-piece solid golf ball of claim 1, wherein the initial velocities of the core, the intermediate layer-encased sphere and the ball satisfy the relationships: −0.1 m/s≤ball initial velocity−core initial velocity≤1 m/s; and −1.3 m/s≤ball initial velocity−initial velocity of intermediate layer-encased sphere≤−0.1 m/s. ### Claim 6 (depends on 1) The multi-piece solid golf hall of claim 1, wherein the material of the intermediate layer includes an ionomer resin having a high acid content of at least 16 wt %. ### Claim 7 (depends on 1) The multi-piece solid golf ball of claim 1, wherein the [core surface hardness (Cs)−core center hardness (Cc)] value, is 22 or more. ### Claim 8 (depends on 1) The multi-piece solid golf hall of claim 1, wherein the (initial velocity of intermediate layer-encased sphere−initial velocity of core) value is −0.10 ins or above. ### Claim 9 A multi-piece solid golf ball comprising a core, a cover and an intermediate layer therebetween, wherein the core, a sphere composed of the core and the intermediate layer which peripherally encases the core (intermediate layer-encased sphere), and the ball have respective surface hardnesses, expressed in terms of Shore D hardness, which satisfy the relationship ball surface hardness surface hardness of intermediate layer-encased sphere≥core surface hardness; the thickness of the cover is not more than 1.2 mm, and the intermediate layer and the cover have respective thicknesses which satisfy the relationship (thickness of intermediate layer−thickness of cover)≥0; and the core has a hardness profile which, expressed in terms of JIS-C hardness, satisfies the following relationships: core center hardness (Cc)≤64, 5≥[hardness at a positions min from core center (C5)−core center hardness (Cc)]>0, and [core surface hardness (Cs)−core center hardness (Cc)]/[hardness at a position midway between core surface and core center (Cm)−core center hardness (Cc)]≥3.0.