Golf ball

• US 20040192473A1
• Filed: 03/25/2004
• Published: 09/30/2004
• Est. Priority Date: 03/28/2003
• Status: Active Grant

• Current Assignee: Bridgestone Sports Co Limited (Bridgestone Corporation)
• Original Assignee: Bridgestone Sports Co Limited (Bridgestone Corporation)
• Inventors: Ichikawa, Yasushi, Kasashima, Atsuki
• Granted Patent: US 7,029,406 B2
• Time in Patent Office: Days
• US Class Current: 473/371
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0017 Specified total dimple volume
• CPC Class Codes: A63B 37/0033 Thickness
• CPC Class Codes: A63B 37/0075 Three piece balls, i.e. cover, intermediate layer and core
• CPC Class Codes: A63B 37/0082 Density; Specific gravity
• CPC Class Codes: A63B 37/0096 Spin rate

Abstract

In a golf ball comprising an elastic core, an intermediate layer of at least one layer, and a cover which is provided on its surface with a plurality of dimples, wherein the cover has a gage of 1.0-1.5 mm, the intermediate layer has a gage of 1.0-2.0 mm per layer, the golf ball in its entirety has a specific gravity of 1.128-1.145 g/cm³. On account of an optimum specific gravity in a relatively high range, the ball is improved in flight performance.

Claims

1. A golf ball comprising an elastic core, an intermediate layer of at least one layer enclosing the elastic core, and a cover which is provided on its surface with a plurality of dimples, wherein

the cover has a gage of 1.0 to 1.5 mm,

the intermediate layer has a gage of 1.0 to 2.0 mm per layer,

the golf ball in its entirety has a specific gravity of at least 1.128 g/cm³.

2. The golf ball of claim 1 wherein the specific gravity of the golf ball is up to 1.145 g/cm³.

3. The golf ball of claim 1 wherein a phantom sphere is given on the assumption that the cover surface is free of dimples, the total of the volumes of dimple spaces each delimited by a concave wall of a dimple and the surface of the phantom sphere is 1.1 to 1.6% of the volume of the phantom sphere.

4. The golf ball of claim 1 wherein the golf ball in flight has a coefficient of lift CL and a coefficient of drag CD, and the ratio CL/CD is 0.676 to 0.796 under a set of conditions:

Reynolds number 200,000 and spin rate 2,700 rpm, 0.813 to 0.933 under a set of conditions;

Reynolds number 120,000 and spin rate 2,400 rpm, and 0.856 to 0.976 under a set of conditions;

Reynolds number 80,000 and spin rate 2,000 rpm.

5. The golf ball of claim 1 wherein the cover is formed by injection molding.