# US 8,783,086 B2 · Method for producing golf club head

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- Number: US 8,783,086 B2
- Document ID: US8783086B2
- Status: Granted
- Kind: B2
- Application number: 13/301,218
- Filed: 2011-11-21
- Published: 2012-05-24
- Granted: 2014-07-22
- Earliest claimed: 2010-11-22
- Assignees: SRI Sports Limited
- Applicants: Tomoya Hirano
- Inventors: Tomoya Hirano
- Web page: https://patentgrep.com/patent/US8783086B2

## CPC

- A63B 53/0466: {wood-type}
- A63B 53/0408: {characterised by specific dimensions, e.g. thickness}
- A63B 53/0437: {with special crown configurations}
- A63B 2209/02: with reinforcing fibres, e.g. carbon, polyamide fibres
- A63B 2209/023: Long, oriented fibres, e.g. wound filaments, woven fabrics, mats
- A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H)

## Abstract

A golf club head has a hollow structure comprising a head main body provided with a opening and a cover covering the opening. The head main body is made of a metal material and provided in the opening with a supporting part for supporting a peripheral edge part of the cover fitted in the opening. The cover is made of a low specific gravity material. A method for producing the golf club head comprises a step of preparing a first workpiece having an opening, which step comprises forming the supporting part through a press working of a sheet metal having a uniform thickness.

## Claims

### Claim 1

A method for producing a golf club head having a hollow structure and including:
a head main body that is made of a metal material and has an opening; and
a cover that is provided to cover the opening of the head main body and is made of a low-specific-gravity material having a lower specific gravity than the metal material,
the method comprising a step of preparing a first workpiece having the opening,
the step of preparing a first workpiece including pressing a sheet material having a uniform thickness to form a supporting part around the opening, the supporting part being recessed stepwise from a head finished surface for supporting a peripheral edge portion of the cover, wherein
a rigidity index GA of the cover which is defined as a product of a tensile strength σ1 of the cover and the thickness t1 of the cover measured in the peripheral edge part supported by the supporting part is 0.45 to 0.80 times
a rigidity index GB of the supporting part of the head main body which is defined as a product of a tensile strength σ2 of the supporting part and the thickness t2 of the supporting part.

### Claim 2 (depends on 1)

The method according to claim 1, wherein
the first workpiece is a crown member that forms a crown portion defining the upper surface of the golf club head and has an opening in the crown portion, and
the cover is made of a fiber-reinforced resin material.

### Claim 3

A method for producing a golf club head having a hollow structure and including:
a head main body that is made of a metal material and has an opening; and
a cover that is provided to cover the opening of the head main body and is made of a low-specific-gravity material having a lower specific gravity than the metal material,
the method comprising a step of preparing a first workpiece having the opening,
the step of preparing a first workpiece including pressing a sheet material having a uniform thickness to form a supporting part around the opening, the supporting part being recessed stepwise from a head finished surface for supporting a peripheral edge portion of the cover, wherein
the supporting part of the head main body has:
a supporting face denting from and being parallel with the outer surface of the head main body around the opening; and
a slant face extending from said outer surface to said supporting face while inclining to the opening, and
the supporting part has a thickness ta of from 0.5 to 1.5 mm at the intersection between the slant face and said outer surface, and
the thickness ta is 0.8 to 1.8 times a thickness tb of the supporting part measured at the edge of the supporting face adjacent to the opening.

### Claim 4 (depends on 3)

The method according to claim 3, wherein
the first workpiece is a crown member that forms a crown portion defining the upper surface of the golf club head and has an opening in the crown portion, and
the cover is made of a fiber-reinforced resin material.