Hollow golf club head and method of manufacturing the same

• US 9,174,100 B2
• Filed: 04/26/2013
• Issued: 11/03/2015
• Est. Priority Date: 06/22/2012
• Status: Active Grant

• Current Assignee: Bridgestone Sports Co Limited (Bridgestone Corporation)
• Original Assignee: Bridgestone Sports Co Limited (Bridgestone Corporation)
• Inventors: Takechi, Takaharu
• Primary Examiner(s): Passaniti, Sebastiano
• Application Number:
  US13/871,621
• Publication Number:
  US 20130344987A1
• Time in Patent Office: 921 Days
• Field of Search: 473324-350, 473287-292
• US Class Current: 1/1
• CPC Class Codes: A63B 2209/00 Characteristics of used materials
• CPC Class Codes: A63B 53/04 Heads
• 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 53/0466 wood-type
• CPC Class Codes: A63B 60/52 with slits
• CPC Class Codes: Y10T 29/49986 Subsequent to metal working
• CPC Class Codes: Y10T 29/49996 Successive distinct removal operations

Abstract

This invention provides a hollow golf club head including a metal plate portion provided with thin and thick portions. A medium thick portion having an intermediate thickness between the thicknesses of the thin and thick portions is formed at the boundary portion between the thin and thick portions. The thin and medium thick portions are formed by the steps of pressing the metal plate portion to form a recess in one surface of the metal plate portion and a projection on its other surface, performing chemical milling of the recess and a portion surrounding it, and removing the projection by grinding.

Claims

1. A hollow golf club head including a metal plate portion provided with a thin portion and a thick portion, wherein

a medium thick portion having an intermediate thickness between a thickness of the thin portion and a thickness of the thick portion is formed at a boundary portion between the thin portion and the thick portion,

the metal plate portion includes a crown portion,

the medium thick portion is formed around the entire thin portion,

the thin portion is formed at the central portion of the crown portion to occupy 30% to 90% of an area of the crown portion, and

a width of the medium thick portion is 5 to 25 mm, the thickness of the thin portion is 30% to 70% of the thickness of the thick portion, and the thickness of the medium thick portion is 50% to 90% of the thickness of the thick portion.

2. The head according to claim 1, wherein

the thin portion and the medium thick portion are formed by the steps of:

pressing the metal plate portion to form a recess in one surface of the metal plate portion and a projection on the other surface thereof;

performing chemical milling of the recess and a portion surrounding the recess; and

removing the projection by grinding, and

wherein

the recess is formed on an inner surface side of the golf club head.

3. The head according to claim 1, wherein

a low-reflection coating is applied onto the outer surface of the metal plate portion.

4. The head according to claim 3, wherein a gloss value of the low-reflection coating is 40 to 70.