Golf ball having a hollow center

• US 10,668,328 B2
• Filed: 12/31/2013
• Issued: 06/02/2020
• Est. Priority Date: 01/09/2013
• Status: Active Grant

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Sullivan, Michael J., Bulpett, David A., Blink, Robert, Binette, Mark L., Comeau, Brian
• Primary Examiner(s): Kim, Eugene L
• Assistant Examiner(s): Stanczak, Matthew B
• Application Number:
  US14/145,633
• Publication Number:
  US 20140194227A1
• Time in Patent Office: 2,345 Days
• Field of Search: 473375
• CPC Class Codes: A63B 37/0039 characterised by the material
• CPC Class Codes: A63B 37/0041 Coefficient of restitution
• CPC Class Codes: A63B 37/0045 Thickness
• CPC Class Codes: A63B 37/0056 Hollow; Gas-filled
• CPC Class Codes: A63B 37/0061 Coefficient of restitution
• CPC Class Codes: A63B 37/00622 Surface hardness
• CPC Class Codes: A63B 37/0064 Diameter
• CPC Class Codes: A63B 37/0076 Multi-piece balls, i.e. having two or more intermediate layers
• CPC Class Codes: A63B 37/0077 Physical properties
• CPC Class Codes: A63B 37/0092 Hardness distribution amongst different ball layers

Abstract

Golf balls including a spherical inner core shell layer formed from a thermoset or thermoplastic composition are provided. The shell layer has an outer surface, an inner surface, and an inner diameter to define a hollow center. A thermoset or thermoplastic outer core layer is formed about the shell layer and optional intermediate layer(s) disposed between the shell layer and the outer core layer. A cover is formed about the outer core layer.

Claims

1. A golf ball comprising a core and a cover, the core comprising:

a spherical shell layer enclosing a spherical hollow interior portion, the shell layer being formed from a thermoset rubber composition and having an outer surface and an inner surface; and

an outer core layer formed from a thermoplastic composition;

wherein the hollow interior portion enclosed by the shell layer has a diameter of from 0.5 inches to 1.1 inches, the shell layer has a thickness of from 0.125 inches to 0.4 inches, and the difference in Shore C surface hardness between the outer surface of the shell layer and the inner surface of the shell layer is from 3 Shore C to 25 Shore C;

wherein the volume of the hollow interior portion enclosed by the shell layer is from 5% to 30% of the total golf ball volume; and

wherein the thermoplastic composition of the outer core layer is a highly neutralized polymer composition having a solid sphere Atti compression of 50 or less and comprising;

an acid copolymer of ethylene and an α

,β

-unsaturated carboxylic acid, optionally including a softening monomer selected from the group consisting of alkyl acrylates and methacrylates;

a non-acid polymer selected from the group consisting of ethylene-alkyl acrylate rubber and ethylene-alkyl methacrylate rubber, present in an amount of from 15 wt % to 50 wt %, based on the combined weight of the acid copolymer and the non-acid polymer;

an organic acid or salt thereof; and

a cation source present in an amount sufficient to neutralize greater than 80% of all acid groups present in the composition.

2. The golf ball of claim 1, wherein the acid copolymer of ethylene and an α

,β

-unsaturated carboxylic acid does not include a softening monomer, and the organic acid salt is magnesium oleate present in an amount of 20 parts or greater per 100 parts of acid copolymer and non-acid copolymer combined.

3. The golf ball of claim 1, wherein the cation source is present in an amount sufficient to neutralize 110% or greater of all acid groups present in the composition.