Multi-piece solid golf ball

Patent metadata

Field	Value
Publication number	US-9764200-B2
Application number	US-201514924000-A
Country	US
Kind code	B2
Filing date	Oct 27, 2015
Priority date	Dec 19, 2014
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

Multi-piece solid golf ball having a core, an envelope layer encasing the core, an intermediate layer encasing the envelope layer, and an outermost layer encasing the intermediate layer, the envelope layer-encased sphere, the intermediate layer-encased sphere and the ball have surface hardnesses which satisfy a specific relationship, the intermediate layer and the cover have thicknesses which satisfy a specific relationship, and 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 core surface and center satisfy specific relationships.

First claim

The invention claimed is:

1. A multi-piece solid golf ball comprising a core, an envelope layer encasing the core, an intermediate layer encasing the envelope layer, and an outermost layer encasing the intermediate layer,
wherein the sphere obtained by peripherally encasing the core with the envelope layer (envelope layer-encased sphere), the sphere obtained by peripherally encasing the envelope layer with the intermediate layer (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>surface hardness of envelope layer-encased sphere;

the intermediate layer and the outermost layer have respective thicknesses which satisfy the relationship
outermost layer thickness <intermediate layer thickness;

the core, the envelope layer-encased sphere, the intermediate layer-encased sphere and the ball have respective initial velocities which satisfy the relationship
ball initial velocity <initial velocity of intermediate layer-encased sphere>initial velocity of envelope layer-encased sphere >core initial velocity; and

the core has a hardness profile which, expressed in terms of JIS-C hardness, satisfies the following relationships:
22≦core surface hardness (Cs)−core center hardness (Cc),

7≧[hardness at a position 5 mm 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.

2. The golf ball of claim 1 , wherein the [hardness at a position midway between core surface and core center (Cm)−core center hardness (Cc)] value, expressed in terms of JIS-C hardness, is 10 or less.

3. The golf ball of claim 1 , wherein the [hardness at a position 5 mm from core center (C5)−core center hardness (Cc)] value, expressed in terms of JIS-C hardness, is 5 or less.

4. The 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, expressed in terms of JIS-C hardness, is 4 or more.

5. The golf ball of claim 1 , wherein the initial velocity of the intermediate layer-encased sphere is larger than the core initial velocity.

6. The 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 from −3 to 3.

7. The golf ball of claim 1 , wherein the initial velocities of the core, the intermediate layer-encased sphere and the ball satisfy the relationships:
(ball initial velocity−core initial velocity)≧−1.0 m/s; and

(ball initial velocity−initial velocity of envelope layer-encased sphere)≧−1.0 m/s.

Assignees

• Bridgestone Sports Co Ltd

Inventors

• Watanabe Hideo
• Kimura Akira

Classifications

• A63B37/0084

  Initial velocity · CPC title

• A63B37/0068

  Initial velocity · CPC title

• A63B37/0045

  Thickness · CPC title

• A63B37/0033

  Thickness · CPC title

• A63B37/0076

  Multi-piece balls, i.e. having two or more intermediate layers · CPC title