Solid golf ball

• US 6,527,652 B1
• Filed: 07/17/2000
• Issued: 03/04/2003
• Est. Priority Date: 07/28/1999
• Status: Expired due to Term

• Current Assignee: Bridgestone Sports Co Limited (Bridgestone Corporation)
• Original Assignee: Bridgestone Sports Co Limited (Bridgestone Corporation)
• Inventors: Yamagishi, Hisashi, Masutani, Yutaka, Maruko, Takashi
• Primary Examiner(s): Graham, Mark S.
• Assistant Examiner(s): Gorden, Raeann
• Application Number:
  US09/618,160
• Time in Patent Office: 960 Days
• Field of Search: 473/376, 473/373, 473/374, 473/377, 473/378, 473/367, 473/368, 473/371
• US Class Current: 473/371
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0031 Hardness
• CPC Class Codes: A63B 37/0033 Thickness
• CPC Class Codes: A63B 37/0043 Hardness
• CPC Class Codes: A63B 37/0045 Thickness
• CPC Class Codes: A63B 37/00622 Surface hardness
• CPC Class Codes: A63B 37/0064 Diameter
• CPC Class Codes: A63B 37/0065 Deflection or compression
• CPC Class Codes: A63B 37/0076 Multi-piece balls, i.e. having two or more intermediate layers
• CPC Class Codes: A63B 37/12 Special coverings , i.e. outer layer material balls with finger holes A63B37/0001, golf ball covers A63B37/0023

Abstract

A multilayer solid golf ball comprising a core and a cover of four layers is characterized in that the core undergoes a deflection of 2.5-5.5 mm under an applied load of 100 kg, the difference in hardness between a first layer of the cover enclosing the core and a second layer of the cover enclosing the first layer is at least 5 Shore D hardness units, the second layer has a Shore D hardness of up to 52, a third layer of the cover enclosing the second layer is harder than the second layer and a fourth layer of the cover enclosing the third layer.

Claims

1. A multilayer solid golf ball comprising a core and a cover of four layers, characterized in that the core undergoes a deflection of 2.5 to 5.5 mm under an applied load of 100 kg, the difference in hardness between a first layer of the cover enclosing the core and a second layer of the cover enclosing the first layer is at least 5 Shore D hardness units, the second layer has a Shore D hardness of up to 52, a third layer of the cover enclosing the second layer is harder than the second layer and a fourth layer of the cover enclosing the third layer, and the second layer of the cover is softer than the first layer of the cover.

2. The solid golf ball of claim 1 wherein the core has a diameter of 26 to 35 mm, the core at its surface has a Shore D hardness of at least 40, and the fourth layer of the cover has a thickness of 0.5 to 3.0 mm.

3. The solid golf ball of claim 1 wherein the second layer of the cover is formed of at least one member selected from the group consisting of polyester resins, polyurethane resins, and thermoplastic polyamide elastomers.

4. The multilayer solid golf ball of claim 1 wherein the forth layer of the cover is formed of polyurethane resins.

5. The multilayer solid golf ball of claim 1 wherein the second layer of the cover has a Shore D hardness of up to 47.

6. The multilayer solid golf ball of claim 1 wherein at least one of a first layer, a second layer and a third layer of the covers is formed of thermoplastic resin.