# US 5,704,852 A · Thread wound golf ball

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- Number: US 5,704,852 A
- Document ID: US5704852A
- Status: Granted
- Kind: A
- Application number: 08/505,005
- Filed: 1995-07-21
- Granted: 1998-01-06
- Earliest claimed: 1994-03-31
- Assignees: Sumitomo Rubber Industries, Ltd.
- Inventors: Akira Kato; Tadahiro Ebisuno
- Web page: https://patentgrep.com/patent/US5704852A

## CPC

- A63B 37/0003: {Golf balls}
- A63B 37/0004: {Surface depressions or protrusions}
- A63B 37/0053: {Thread wound}
- A63B 37/0054: {Substantially rigid, e.g. metal}
- A63B 37/0064: {Diameter}
- A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H)

## Abstract

The present invention provides a thread wound golf ball which keeps good hit feeling inherently holding in thread wound golf balls and attains long flying distance which is equal to that attained by the two-piece solid golf ball. The thread wound golf ball comprises a center composed of a vulcanized molded article of a rubber composition, a thread rubber layer formed on said center and a cover covering on said thread rubber layer, wherein said center has a diameter of 30 to 35 mm and a strain amount formed between an initial loading of 10 kg and a final loading of 30 kg is 1.2 to 2.5 mm. The cover of the thread rubber layer has many dimples thereon and the product of total volume of the dimples and the diameter of the center is 8,500 to 11,000 mm.sup.3.mm.

## Claims

### Claim 1

A thread wound golf ball comprising a center composed of a vulcanized molded article of a rubber composition, a thread rubber layer formed on said center and a cover covering said thread rubber layer, wherein (a) said center has a diameter of 30 to 35 mm and a strain amount formed between an initial loading of 10 Kg and a final loading of 30 Kg is 1.2 to 2.5 mm and (b) the cover has many dimples thereon, and the product of total volume of the dimples and the diameter of the center is 8,500 to 11,000 mm.sup.3.mm.

### Claim 2 (depends on 1)

The thread wound golf ball according to claim 1, wherein the center is a vulcanized molded article of a rubber composition comprising 100 parts by weight of a rubber and 5 to 80 parts by weight of a thermoplastic resin.

### Claim 3 (depends on 1)

The thread wound golf ball according to claim 1, wherein the center is a vulcanized molded article of a rubber composition comprising 100 parts by weight of a rubber, 5 to 80 parts by weight of a thermoplastic resin, 2 to 12 parts by weight of sulfur, 1 to 4 parts by weight of a vulcanization accelerator and 10 to 150 parts by weight of a weight adjustor.

### Claim 4 (depends on 1)

The thread wound golf ball according to claim 1, wherein the center is a vulcanized molded article of a rubber composition comprising 100 parts by weight of a rubber and 4 to 18 parts by weight of metal salts of .alpha.,.beta.-unsaturated carboxylic acid.

### Claim 5 (depends on 1)

The thread wound golf ball according to claim 1, wherein the center is a vulcanized molded article of a rubber composition comprising 100 parts by weight of a rubber, 4 to 18 parts by weight of metal salts of .alpha.,.beta.-unsaturated carboxylic acid, 0.5 to 3 parts by weight of an initiator and 20 to 100 parts by weight of a weight adjustor.

### Claim 6 (depends on 1, 2, 3)

The thread wound golf ball according to any one of claims 1 to 3, wherein the rubber of the center is a high-cis polybutadiene or mainly contains high-cis polybutadiene.

### Claim 7 (depends on 2, 3)

The thread wound golf ball according to any one of claim 2 or 3, wherein the thermoplastic resin is a high-styrene resin or a high-molecular weight polyolefin or a mixture thereof.

### Claim 8 (depends on 1)

The thread wound golf ball according to claim 1, wherein the height of rebound of the center is 120 cm or more when dropping the center on concrete from the height of 254 cm.