IP Library Granted Patent US 8,858,355
Granted Patent B2
US 8,858,355 · App. 13/644,949 · Granted Oct 14, 2014

Golf club

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Quick Facts
Patent No.
US 8,858,355
App. No.
13/644,949
Granted
Oct 14, 2014
Kind
B2
Abstract

Provided is a golf club having a head disposed at a front end of a shaft and a grip disposed at a back end of the shaft. A club weight is not larger than 290 g, and a ratio (head weight/club weight) of a head weight to a club weight is not lower than 0.67 but not higher than 0.72. When an inertia moment of the club at a grip end is MI, 2700 kg·cm 2 ≦MI≦3000 kg·cm 2 is satisfied, and when a frequency of flexural vibration of the club is F, 190 cpm≦F≦230 cpm is satisfied.

Claims (24)

1. A golf club having a head disposed at a front end of a shaft and a grip disposed at a back end of the shaft, wherein

a club weight is not larger than 290 g,

a ratio (head weight/club weight) of a head weight to the club weight is not lower than 0.67 but not higher than 0.72,

when an inertia moment of the club at an end of the grip is MI, 2700 kg·cm 2 ≦MI≦3000 kg·cm 2 is satisfied, and

when a frequency of flexural vibration of the club is F, 190 cpm≦F≦230 cpm is satisfied.

2. The golf club according to claim 1 , wherein when a distance from the front end of the shaft to a center of gravity of the shaft is L G and when a full length of the shaft is L S , 0.52≦L G /L S ≦0.65 is satisfied.

3. The golf club according to claim 1 , wherein a club length is not larger than 46 inches.

4. The golf club according to claim 1 , wherein the club weight is not smaller than 265 g but not larger than 290 g.

5. The golf club according to claim 1 , wherein a club length is not smaller than 42 inches but not larger than 46 inches.

6. The golf club according to claim 1 , wherein the frequency of the flexural vibration of the club is not lower than 200 cpm but not higher than 220 cpm.

7. The golf club according to claim 1 , wherein the head weight is not smaller than 185 g but not larger than 210 g.

8. The golf club according to claim 1 , wherein the ratio of the head weight to the club weight is not lower than 0.68 but not higher than 0.715.

9. The golf club according to claim 1 , wherein a weight of the grip is not smaller than 30 g but not larger than 41 g.

10. The golf club according to claim 1 , wherein a weight of the shaft is not smaller than 30 g but not larger than 58 g.

11. The golf club according to claim 1 , wherein a length of the shaft is not smaller than 1050 mm but not larger than 1200 mm.

12. The golf club according to claim 1 , wherein when a distance from the front end of the shaft to a center of gravity of the shaft is L G and when a full length of the shaft is L S , 0.54≦L G /L S ≦0.63 is satisfied.

13. The golf club according to claim 1 , wherein a weight of a butt partial layer of the shaft with respect to the shaft weight is not smaller than 5 wt % but not larger than 50 wt %.

14. The golf club according to claim 1 , wherein when a weight of a butt partial layer existing in a range from a butt end of the shaft to a point separated from the butt end by 250 mm is represented as Wa, and when a weight of the shaft in said range is represented as Wb, Wa/Wb is not lower than 0.4 but not higher than 0.7.

15. The golf club according to claim 1 , wherein a fiber elastic modulus of a butt partial layer is not lower than 5 t/mm 2 but not higher than 20 t/mm 2 .

16. The golf club according to claim 1 , wherein a resin content of a butt partial layer is not lower than 20 mass % but not higher than 50 mass %.

17. The golf club according to claim 1 , wherein a weight of a butt straight layer with respect to the shaft weight is not smaller than 5 mass % but not larger than 50 mass %.

18. The golf club according to claim 1 , wherein a fiber elastic modulus of a butt straight layer is not lower than 5 t/mm 2 but not higher than 20 t/mm 2 .

19. The golf club according to claim 1 , wherein a resin content of a butt straight layer is not lower than 20 mass % but not higher than 50 mass %.

20. The golf club according to claim 2 , wherein a club length is not larger than 46 inches.

Assignments (2)
MERGER Recorded Apr 17, 2018
From: DUNLOP SPORTS CO. LTD.
To: SUMITOMO RUBBER INDUSTRIES, LTD.
Reel/Frame 045959/0204 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 11, 2012
From: NAKAMURA, TAKASHI; HASEGAWA, HIROSHI; NAKANO, TAKASHI
To: DUNLOP SPORTS CO. LTD.
Reel/Frame 029111/0455 →