Hollow golf club head

• US 20060035720A1
• Filed: 08/15/2005
• Published: 02/16/2006
• Est. Priority Date: 12/28/2001
• Status: Active Grant

• Current Assignee: Yokohama Rubber Company Limited
• Original Assignee: Yokohama Rubber Company Limited
• Inventors: Miyamoto, Masahiko, Mori, Tomoaki, Nakahara, Norihiko
• Granted Patent: US 7,204,768 B2
• Time in Patent Office: Days
• US Class Current: 473/329
• CPC Class Codes: A63B 2209/00 Characteristics of used materials
• CPC Class Codes: A63B 2209/02 with reinforcing fibres, e.g. carbon, polyamide fibres
• CPC Class Codes: A63B 2209/023 Long, oriented fibres, e.g. wound filaments, woven fabrics, mats
• CPC Class Codes: A63B 53/0408 characterised by specific dimensions, e.g. thickness
• CPC Class Codes: A63B 53/0416 Heads having an impact surface provided by a face insert
• CPC Class Codes: A63B 53/0433 with special sole configurations
• CPC Class Codes: A63B 53/0437 with special crown configurations
• CPC Class Codes: A63B 53/045 Strengthening ribs
• CPC Class Codes: A63B 53/0454 Strengthening ribs on the rear surface of the impact face plate
• CPC Class Codes: A63B 53/0458 with non-uniform thickness of the impact face plate
• CPC Class Codes: A63B 53/0466 wood-type

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, 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, and the ratio of the face area of a portion where the reinforcement and the head body are combined to the face area of the head body is set equal or superior to 20%.

Claims

1-8. -8. (canceled)

9. A hollow golf club head comprising a hollow head body wherein at least a part of a crown portion and at least a part of a face portion of the head body are composed of a material different from the remainder of said head body, and a ratio (ρ

b/ρ

c) of a specific gravity ρ

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

c of said crown portion is set equal to or greater than 1.3