HOLLOW GOLF CLUB HEAD

• US 20180001159A1
• Filed: 06/21/2017
• Published: 01/04/2018
• Est. Priority Date: 06/30/2016
• Status: Active Grant

• Current Assignee: Sumitomo Rubber Industries Limited
• Original Assignee: Dunlop Sports Co. Ltd. (Sumitomo Rubber Industries Limited)
• Inventors: MIZUTANI, Naruhiro
• Granted Patent: US 10,086,241 B2
• Time in Patent Office: Days
• CPC Class Codes: A63B 2053/0491 with added weights, e.g. changeable, replaceable
• 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 53/0466 wood-type
• CPC Class Codes: A63B 53/08 with special arrangements for obtaining a variable impact
• CPC Class Codes: A63B 60/52 with slits

Abstract

A head 2 includes a face 10 and a sole 6. The face 10 has a face center Fc. The sole 6 includes a groove 20 extending from a toe side to a heel side. The whole groove 20 is located below the face center Fc. A bottom part of the groove 20 is curved so that it projects to a lower side along a shape of the sole 6. A maximum value of a groove depth D of the groove 20 is 5% or greater but 15% or less of a height of a center of gravity of the head. The head 2 is a hollow golf club head.

Claims

1. A hollow golf club head comprising:

a face; and

a sole,

wherein;

the face has a face center;

the sole includes a groove extending from a toe side to a heel side;

the whole groove is located below the face center;

a bottom part of the groove is curved so that it projects to a lower side along a shape of the sole; and

a maximum value of a groove depth of the groove is 5% or greater but 15% or less of a height of a center of gravity of the head.

2. The golf club head according to claim 1, wherein the maximum value of the groove depth is equal to or less than 10% of the height of the center of gravity of the head.

3. The golf club head according to claim 1, wherein the golf club head satisfies the following item (x), (y), or (z):

(x) the groove depth is gradually decreased as the groove depth approaches a toe end in a toe side end part of the groove, and the groove depth becomes zero in the toe end;

(y) the groove depth is gradually decreased as the groove depth approaches a heel end in a heel side end part of the groove, and the groove depth becomes zero in the heel end;

(z) the groove depth is gradually decreased as the groove depth approaches the toe end in the toe side end part of the groove, and the groove depth becomes zero in the toe end; and

the groove depth is gradually decreased as the groove depth approaches the heel end in the heel side end part of the groove, and the groove depth becomes zero in the heel end.

4. The golf club head according to claim 1, wherein the maximum value of the groove depth is 0.8 mm or greater but 3.2 mm or less.

5. The golf club head according to claim 1,

wherein:

the groove includes a center groove part, a toe groove part located on the toe side with respect to the center groove part, and a heel groove part located on the heel side with respect to the center groove part; and

the golf club head satisfies the following item (a), (b), or (c);

(a) a groove depth of the center groove part is smaller than a groove depth of the toe groove part;

(b) the groove depth of the center groove part is smaller than a groove depth of the heel groove part;

(c) the groove depth of the center groove part is smaller than the groove depth of the toe groove part, and the groove depth of the center groove part is smaller than the groove depth of the heel groove part.

6. The golf club head according to claim 1, wherein if a toe-heel direction length of the groove is defined as Lm, and a toe-heel direction width of the head is defined as Lh, Lm/Lh is 0.7 or greater but 0.92 or less.

7. The golf club head according to claim 1, wherein the golf club head satisfies the following item (z):

(z) the groove depth is gradually decreased as the groove depth approaches a toe end in a toe side end part of the groove, and the groove depth becomes zero in the toe end; and

the groove depth is gradually decreased as the groove depth approaches a heel end in a heel side end part of the groove, and the groove depth becomes zero in the heel end.

8. The golf club head according to claim 1, wherein the groove depth is equal to or less than 5 mm at all positions in a toe-heel direction.

9. The golf club head according to claim 1, wherein a sole thickness in the groove is 0.5 mm or greater but 1.4 mm or less.

10. The golf club head according to claim 4, wherein the maximum value of the groove depth is equal to or less than 2.7 mm.

11. The golf club head according to claim 4, wherein the maximum value of the groove depth is equal to or less than 2.2 mm.

12. The golf club head according to claim 1, wherein if a height of the face center from a horizontal plane is defined as H1 (mm), the height of the center of gravity of the head is (H1−

5) mm or greater but (H1+1) mm or less.