Golf club head

• US 8,827,833 B2
• Filed: 02/21/2013
• Issued: 09/09/2014
• Est. Priority Date: 02/22/2012
• Status: Active Grant

• Current Assignee: K.K. Endo Seisakusho
• Original Assignee: K.K. Endo Seisakusho
• Inventors: Amano, Junichi, Tamaki, Toru
• Primary Examiner(s): Layno, Benjamin
• Application Number:
  US13/773,107
• Publication Number:
  US 20130217513A1
• Time in Patent Office: 565 Days
• Field of Search: 473/331, 473/330, 473/329
• US Class Current: 473/331
• CPC Class Codes: A63B 2225/60 Apparatus used in water
• CPC Class Codes: A63B 53/04 Heads
• CPC Class Codes: A63B 53/0445 Details of grooves or the like on the impact surface
• CPC Class Codes: A63B 53/047 iron-type
• CPC Class Codes: A63B 60/00 Details or accessories of golf clubs, bats, rackets or the like
• CPC Class Codes: B41M 5/24 Ablative recording, e.g. by burning marks; Spark recording marking by high energetic means, e.g. by laser otherwise than burning or ablative removal B41M5/26; materials or methods for recording or reproduction by optical means G11B7/00

Abstract

There is provided a golf club head capable of reliably preventing a backspin rate from varying in rainfall. A plurality of fine grooves are formed on a face surface 2. When observing a cross-sectional surface perpendicular to the face surface 2 involving a vertical line passing through the center G of gravity of the golf club head 1 with the golf club head 1 set at preset loft and lie angles, an average width of the fine grooves 4 in the cross-sectional surface is 100 μm or less and an average pitch thereof in the cross-sectional surface is 100 μm or less. Hence, the discharge of water can be accelerated by a capillary phenomenon, making it possible to reliably prevent a backspin rate of a golf ball from varying in rainfall.

Claims

1. A golf club head comprising:

a plurality of fine grooves formed on a face surface thereof, said fine grooves having an average width of 100 μ

m or less in a cross-sectional surface perpendicular to said face surface and an average pitch of 100 μ

m or less in the cross-sectional surface, when the cross-sectional surface perpendicular to said face surface involving a vertical line passing through the center of gravity of said golf club head is observed, with said golf club head set at preset loft and lie angles.

2. The golf club head according to claim 1, wherein the average width of said fine grooves in said cross-sectional surface is 50 μ

m or less and the average pitch of said fine grooves in said cross-sectional surface is 50 μ

m or less.

3. The golf club head according to claim 2, wherein said fine grooves are formed at least in the vicinity of a point of intersection between said face surface and a vertical line dropped from the center of gravity of said golf club head to said face surface.

4. The golf club head according to claim 3, wherein said face surface includes a plurality of score lines, and satisfies the following relationships:

n>

L/100 (μ

m),

0.3(P−

H)<

L,

0<

d<

30 (μ

m), and

2<

Ra<

5 (μ

m)

wherein, in said cross-sectional surface, n denotes the number of protrusions formed by said fine grooves, L denotes a distance between the protrusions located at both the farthermost ends in an approximately flat portion between adjacent score lines of said score lines, P denotes a distance between centers of said adjacent score lines, H denotes a score line width measured by the 30 degree method of measurement, d denotes an average value of level differences between depressions and the protrusions which are formed by said fine grooves, and Ra denotes surface roughness in a region formed with said fine grooves.

5. The golf club head according to claim 4, wherein said fine grooves are formed by processes involving a laser process.

6. The golf club head according to claim 5, comprising:

a base material;

a first plated layer applied to an upper portion of said base material, and

a second plated layer applied to an upper portion of said first plated layer,

wherein said fine grooves are formed by cutting grooves on said first plated layer using a laser process and then applying said second plated layer to an upper portion of said first plated layer thus grooved.

7. The golf club head according to claim 3, wherein said fine grooves are formed by processes involving a laser process.

8. The golf club head according to claim 7, comprising:

a base material;

a first plated layer applied to an upper portion of said base material, and

a second plated layer applied to an upper portion of said first plated layer,

wherein said fine grooves are formed by cutting grooves on said first plated layer using a laser process and then applying said second plated layer to an upper portion of said first plated layer thus grooved.

9. The golf club head according to claim 2, wherein said fine grooves are formed by processes involving a laser process.

10. The golf club head according to claim 9, comprising:

a base material;

a first plated layer applied to an upper portion of said base material; and

a second plated layer applied to an upper portion of said first plated layer,

wherein said fine grooves are formed by cutting grooves on said first plated layer using a laser process and then applying said second plated layer to an upper portion of said first plated layer thus grooved.

11. The golf club head according to claim 1, wherein said fine grooves are formed at least in the vicinity of a point of intersection between said face surface and a vertical line dropped from the center of gravity of said golf club head to said face surface.

12. The golf club head according to claim 11, wherein said face surface includes a plurality of score lines, and satisfies the following relationships:

n>

L/100 (μ

m),

0.3(P−

H)<

L,

0<

d<

30 (μ

m), and

2<

Ra<

5 (μ

m)

wherein, in said cross-sectional surface, n denotes the number of protrusions formed by said fine grooves, L denotes a distance between the protrusions located at both the farthermost ends in an approximately flat portion between adjacent score lines of said score lines, P denotes a distance between centers of said adjacent score lines, H denotes a score line width measured by the 30 degree method of measurement, d denotes an average value of level differences between depressions and the protrusions which are formed by said fine grooves, and Ra denotes surface roughness in a region formed with said fine grooves.

13. The golf club head according to claim 12, wherein said fine grooves are formed by processes involving a laser process.

14. The golf club head according to claim 13, comprising:

a base material;

a first plated layer applied to an upper portion of said base material, and

a second plated layer applied to an upper portion of said first plated layer,

wherein said fine grooves are formed by cutting grooves on said first plated layer using a laser process and then applying said second plated layer to an upper portion of said first plated layer thus grooved.

15. The golf club head according to claim 11, wherein said fine grooves are formed by processes involving a laser process.

16. The golf club head according to claim 15, comprising:

a base material;

a first plated layer applied to an upper portion of said base material, and

a second plated layer applied to an upper portion of said first plated layer,

wherein said fine grooves are formed by cutting grooves on said first plated layer using a laser process and then applying said second plated layer to an upper portion of said first plated layer thus grooved.

17. The golf club head according to claim 1, wherein said fine grooves are formed by processes involving a laser process.

18. The golf club head according to claim 17, comprising:

a base material;

a first plated layer applied to an upper portion of said base material, and

a second plated layer applied to an upper portion of said first plated layer,

wherein said fine grooves are formed by cutting grooves on said first plated layer using a laser process and then applying said second plated layer to an upper portion of said first plated layer thus grooved.