# US 7,611,423 B2 · Golf club head

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- Number: US 7,611,423 B2
- Document ID: US7611423B2
- Status: Granted
- Kind: B2
- Application number: 11/434,191
- Filed: 2006-05-16
- Published: 2007-06-07
- Granted: 2009-11-03
- Earliest claimed: 2005-12-05
- Assignees: Bridgestone Sports Co., Ltd.
- Inventors: Hideo Matsunaga; Wataru Ban; Hideo Shimazaki
- Web page: https://patentgrep.com/patent/US7611423B2

## CPC

- A63B 53/04: Heads
- A63B 53/047: {iron-type}
- A63B 53/0475: {with one or more enclosed cavities}
- A63B 60/00: Details or accessories of golf clubs, bats, rackets or the like
- A63B 53/0416: {Heads having an impact surface provided by a face insert}
- A63B 60/54: with means for damping vibrations
- A63B 2053/0491: {with added weights, e.g. changeable, replaceable}
- A63B 2209/00: Characteristics of used materials
- A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H)

## Abstract

This invention provides a golf club head having a first viscoelastic body made of a first viscoelastic material and a second viscoelastic body made of a second viscoelastic material with a loss coefficient the temperature dependence of which is different from that of a loss coefficient of the first viscoelastic material.

## Claims

### Claim 1

An iron type golf club head comprising:
a head main body;
a face plate fixed to a front surface side of said head main body to form a face surface;
a cavity portion formed in said head main body, said cavity portion open to the front surface side; and
a plurality of viscoelastic bodies disposed within said cavity portion,
wherein said plurality of viscoelastic bodies are made of viscoelastic materials with loss coefficients the temperature dependences of which are different,
wherein said plurality of viscoelastic bodies are arranged along a rear surface of said face plate, and
wherein each viscoelastic body is in tight contact with the rear surface of said face plate.

### Claim 2 (depends on 1)

The head according to claim 1, wherein said plurality of viscoelastic bodies are arranged in a toe-heel direction.

### Claim 3 (depends on 1)

The head according to claim 1, wherein said plurality of viscoelastic bodies are arranged in a vertical direction.

### Claim 4 (depends on 1)

The head according to claim 1, wherein an axial edge on the front surface of a circumferential wall defining said cavity portion comprises:
a contacting portion that contacts the rear surface of said face plate; and
a non-contacting portion spaced apart from the rear surface of said face plate to form a gap between said non-contacting portion and the rear surface of said face plate.

### Claim 5 (depends on 1)

The head according to claim 1, further comprising a rear viscoelastic body disposed behind the plurality of viscoelastic bodies within said cavity portion.

### Claim 6

An iron type golf club head comprising:
a head main body;
a face plate fixed to a front surface side of said head main body to form a face surface;
a cavity portion formed in said head main body, said cavity portion open to the front surface side;
a first viscoelastic body disposed within said cavity portion; and
a second viscoelastic body disposed within said cavity portion,
wherein said first and second viscoelastic bodies are made of viscoelastic materials with loss coefficients the temperature dependences of which are different,
wherein said second viscoelastic body includes a portion covering a circumferential surface of said first viscoelastic body, and
wherein said first viscoelastic body and said portion of said second viscoelastic body are in tight contact with a rear surface of said face plate.

### Claim 7 (depends on 6)

The head according to claim 6, wherein said second viscoelastic body includes another portion covering a rear portion of said first viscoelastic body.

### Claim 8 (depends on 6)

The head according to claim 6, wherein an axial edge on the front surface of a circumferential wall defining said cavity portion comprises:
a contacting portion that contacts the rear surface of said face plate; and
a non-contacting portion spaced apart from the rear surface of said face plate to form a gap between said non-contacting portion and the rear surface of said face plate.

### Claim 9 (depends on 6)

The head according to claim 6, further comprising a rear viscoelastic body disposed behind said first and second viscoelastic bodies within said cavity portion.