Hollow golf club head

• US 20030125127A1
• Filed: 12/26/2002
• Published: 07/03/2003
• Est. Priority Date: 12/28/2001
• Status: Active Grant

• Current Assignee: Yokohama Rubber Company Limited
• Original Assignee: Yokohama Rubber Company Limited
• Inventors: Yamamoto, Shinji, Mori, Tomoaki, Nakahara, Norihiko, Nishizawa, Yoh
• Granted Patent: US 7,037,214 B2
• Time in Patent Office: Days
• US Class Current: 473/329
• CPC Class Codes: A63B 2209/02 with reinforcing fibres, e.g. carbon, polyamide fibres
• CPC Class Codes: A63B 53/04 Heads
• CPC Class Codes: A63B 53/0408 characterised by specific dimensions, e.g. thickness
• CPC Class Codes: A63B 53/0433 with special sole configurations
• CPC Class Codes: A63B 53/0437 with special crown configurations
• CPC Class Codes: A63B 53/0466 wood-type
• CPC Class Codes: A63B 60/00 Details or accessories of golf clubs, bats, rackets or the like
• CPC Class Codes: A63B 60/02 Ballast means for adjusting the centre of mass A63B60/24, A63B60/54 take precedence

Abstract

A hollow golf club head allowing to increase the repulsion and the degree of design freedom, while maintaining the durability. A hollow golf club head having a head body formed from a metal, wherein a hole is formed in the vicinity of the middle of a crown portion in the head body, the hole is closed with a cover member made of a material different from the head body, and the ratio (ρm/ρf) of the specific gravity ρm of the head body and the specific gravity ρf of the cover member is set equal or superior to 1.3.

Claims

1. A hollow golf club head having a head body formed from a metal, wherein a hole is formed in the vicinity of the middle of a crown portion in said head body, the hole is closed with a cover member made of a material different from said head body, and the ratio (ρ

m/ρ

f) of the specific gravity ρ

m of said head body and the specific gravity ρ

f of said cover member is set equal or superior to 1.3.

7. The hollow golf club head of any one of claims 1 to 4, wherein the material of said cover member is fiber reinforced plastic.

8. The hollow golf club head of any one of claims 1 to 4, wherein the material of said cover member is one of magnesium alloy, aluminum alloy and titanium alloy.

9. The hollow golf club head of any one of claims 1 to 4, wherein the material of said cover member is one of rubber and resin.

10. The hollow golf club head of any one of claims 1 to 4, wherein the total mass Wf of the cover member closing said hole is made lighter than the total mass Wx of the removed portion of said head body determined from the product of the virtual area of said hole, the virtual thickness of said hole and the specific gravity ρ

m of said head body.

2. A hollow golf club head having a head body formed from a metal, wherein holes are formed respectively in the vicinity of the middle of a crown portion and a sole portion in said head body, each of the holes is closed. with a cover member made of a material different from said head body, and the ratio (ρ

m/ρ

f) of the specific gravity ρ

m of said head body and the specific gravity ρ

f of said cover member is set equal or superior to 1.3.

3. A hollow golf club head having a head body formed from a metal, wherein a hole is formed in the vicinity of the middle of a crown portion in said head body, a flange spreading over a hollow space is formed at least on a part of the peripheral edge of said crown portion, the hole is closed with a cover member made of a material different from said head body, and the ratio (ρ

m/ρ

f) of the specific gravity ρ

m of said head body and the specific gravity ρ

f of said cover member is set equal or superior to 1.3.

5. The hollow golf club head of claim 3 or 4, wherein said flange is disposed at least on a face side of said head body, and said cover member is superimposed on the face side flange with an overlap margin of equal or superior to 5 mm in width.

6. The hollow golf club head of claim 5, wherein the width of the face side flange is equal or superior to 5 mm and less than 30 mm.

4. A hollow golf club head having a head body formed from a metal, wherein holes are formed respectively in the vicinity of the middle of a crown portion and a sole portion in said head body, a flange spreading over a hollow space is formed at least on a part of the peripheral edge of said crown portion, another flange spreading under the hollow space is formed at least on a part of the peripheral edge of said sole portion, each of the holes is closed with a cover member made of a material different from said head body, and the ratio (ρ

m/ρ

f) of the specific gravity ρ

m of said head body and the specific gravity ρ

f of said cover member is set equal or superior to 1.3.

11. A hollow golf club head, wherein at least a part of the crown portion is composed of a material different from a head body thereof, and the ratio (ρ

b/ρ

c) of the specific gravity ρ

b of a portion of said head body excluding the crown portion and the specific gravity ρ

c of said crown portion is set equal or superior to 1.3.