Golf club

Patent metadata

Field	Value
Publication number	US-9682292-B2
Application number	US-201514937664-A
Country	US
Kind code	B2
Filing date	Nov 10, 2015
Priority date	Jul 22, 2013
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

The club length of a golf club is 43 inches or greater and 48 inches or less. A club inertia moment Ix about a swing axis is equal to or less than 6.90×10 3 (kg·cm 2 ). A ratio (Ihs/Ix) is equal to or greater than 0.88, if a head inertia moment about the swing axis is defined as Ihs (kg·cm 2 ). The inertia moment Ix (kg·cm 2 ) is calculated by Equation (1) below, and the inertia moment Ihs (kg·cm 2 ) is calculated by Equation (2) below:

Ix=Wc ×( Lc +60) 2 +Ic   (1)

Ihs=Wh ×( Lh +60) 2 +Ih   (2).

First claim

What is claimed is:

1. A golf club comprising:
a head having a head weight defined as Wh (kg);
a shaft comprising a grip end, a tip end opposite of the grip end, and a shaft axis extending in an axial direction;
a grip;
a club weight defined as Wc (kg);
a club length greater than or equal to 43 in and less than or equal to 48 in;
an axial direction distance between the grip end of the shaft and a center of gravity of the golf club defined as Lc (cm);
an axial direction distance between the grip end of the shaft and a center of gravity of the head defined as Lh (cm);
a club moment of inertia about an axis parallel to a virtual axis of swing and passing through the center of gravity of the golf club defined as Ic (kg·cm 2 );
a club moment of inertia about the virtual axis of swing defined as Ix (kg·cm 2 ) and calculated by the following formula (1):
Ix=Wc ×( Lc+ 60) 2 +Ic   (1)

a head moment of inertia about an axis parallel to the virtual axis of swing and passing through the center of gravity of the head defined as Ih (kg·cm 2 ); and
a head moment of inertia about the virtual axis of swing defined as Ihs (kg·cm 2 ) and calculated by the following formula (2):
Ihs=Wh ×( Lh+ 60) 2 +Ih   (2)

wherein a ratio Ihs/Ix is equal to or greater than 0.88.

2. The golf club according to claim 1 , wherein Ix is greater than or equal to about 6.30×10 3 kg·cm 2 .

3. The golf club according to claim 1 , further comprising:
a shaft weight defined as Ws (kg);
an axial direction distance from the grip end to a center of gravity of the shaft defined as Ls (cm);
a shaft moment of inertia about an axis parallel to the virtual axis of swing and passing through the center of gravity of the shaft defined as Is (kg·cm 2 ); and
a shaft moment of inertia about the virtual axis of swing defined as Iss (kg·cm 2 ) and calculated by the following equation (3):
Iss=Ws ×( Ls+ 60) 2 +Is   (3)

wherein Iss is equal to or less than 700 kg·cm 2 .

4. The golf club according to claim 3 , wherein a ratio Iss/Ix is greater than or equal to 0.092 and less than or equal to 0.120.

5. The golf club according to claim 1 , further comprising:
a grip weight defined as Wg (kg);
an axial direction distance from the grip end to a center of gravity of the grip defined as Lg (cm);
a grip moment of inertia about an axis parallel to the virtual axis of swing and passing through the center of gravity of the grip defined as Ig (kg·cm 2 ); and
a grip moment of inertia about the virtual axis of swing defined as Igs (kg·cm 2 ) and calculated by the following formula (4):
Igs=Wg ×( Lg+ 60) 2 +Ig   (4)

wherein Igs is equal to or less than 150 kg·cm 2 .

6. The golf club according to claim 1 , further comprising:
an axial direction distance from a shaft tip end to a center of gravity of the shaft defined as Lf 1 (cm); and
a shaft length defined as Lf 2 (cm),
wherein Lf 1 /Lf 2 is greater than or equal to 0.55 and less than or equal to 0.67.

7. The golf club according to claim 1 , wherein Wh is greater than or equal to 0.175 kg and less than or equal to 0.200 kg.

8. The golf club according to claim 1 , wherein the ratio Ihs/Ix is less than or equal to 0.93.

9. The golf club according to claim 1 , wherein Ix is greater than or equal to about 6.35×10 3 kg·cm 2 .

10. A golf club comprising:
a head having a head weight defined as Wh (kg);
a shaft comprising a grip end, a tip end opposite of the grip end, a shaft axis extending in an axial direction, and a shaft weight defined as Ws (kg);
a grip having a grip weight defined as Wg (kg);
a club weight defined as We (kg);
an axial direction distance between the grip end of the shaft and a center of gravity of the golf club defined as Lc (cm);
an axial direction distance between the grip end of the shaft and a center of gravity of the head defined as Lh (cm);
an axial direction distance from the grip end to a center of gravity of the shaft defined as Ls (cm);
an axial direction distance from the grip end to a center of gravity of the grip defined as Lg (cm);
a club moment of inertia about an axis parallel to a virtual axis of swing and passing through the center of gravity of the golf club defined as Ic (kg·cm 2 );
a club moment of inertia about the virtual axis of swing defined as Ix (kg·cm 2 ) and calculated by the following formula (1):
Ix=Wc ×( Lc+ 60) 2 +Ic   (1)

a head moment of inertia about an axis parallel to the virtual axis of swing and passing through the center of gravity of the head defined as Ih (kg·cm 2 );
a head moment of inertia about the virtual axis of swing defined as Ihs (kg·cm 2 ) and calculated by the following formula (2):
Ihs=Wh ×( Lh+ 60) 2 +Ih   (2)

a shaft moment of inertia about an axis parallel to the virtual axis of swing and passing through the center of gravity of the shaft defined as Is (kg·cm 2 );
a shaft moment of inertia about the virtual axis of swing defined as Iss (kg·cm 2 ) and calculated by the following equation (3):
Iss=Ws ×( Ls+ 60) 2 +Is   (3)

a grip moment of inertia about an axis parallel to the virtual axis of swing and passing through the center of gravity of the grip defined as Ig (kg·cm 2 ); and
a grip moment of inertia about the virtual axis of swing defined as Igs (kg·cm 2 ) and calculated by the following formula (4):
Igs=Wg ×( Lg+ 60) 2 +Ig   (4)

wherein:
a ratio Ihs/Ix is equal to or greater than 0.88;
Iss is equal to or less than 700 kg·cm 2 ; and
Igs is equal to or less than 150 kg·cm 2 .

11. The golf club according to claim 10 , wherein Ix is greater than or equal to about 6.30×10 3 kg·cm 2 .

12. The golf club according to claim 10 , wherein a ratio Iss/Ix is greater than or equal to 0.092 and less than or equal to 0.120.

13. The golf club according to claim 10 , further comprising:
an axial direction distance from a shaft tip end to the center of gravity of the shaft defined as Lf 1 (cm); and
a shaft length defined as Lf 2 (cm),
wherein Lf 1 /Lf 2 is greater than or equal to 0.55 and less than or equal to 0.67.

14. The golf club according to claim 10 , wherein Wh is greater than or equal to 0.175 kg and less than or equal to 0.200 kg.

15. The golf club according to claim 10 , wherein the ratio Ihs/Ix is less than or equal to 0.93.

16. The golf club according to claim 10 , wherein Ix is greater than or equal to about 6.35×10 3 kg·cm 2 .

17. A golf club comprising:
a head having a head weight defined as Wh (kg) and a volume greater than or equal to 420 cc;
a shaft comprising a grip end, a tip end opposite of the grip end, and a shaft axis extending in an axial direction;
a grip;
a club weight defined as We (kg);
an axial direction distance between the grip end of the shaft and a center of gravity of the golf club defined as Lc (cm);
an axial direction distance between the grip end of the shaft and a center of gravity of the head defined as Lh (cm);
a club moment of inertia about an axis parallel to a virtual axis of swing and passing through the center of gravity of the golf club defined as Ic (kg·cm 2 );
a club moment of inertia about the virtual axis of swing defined as Ix (kg·cm 2 ) and calculated by the following formula (1):
Ix=Wc ×( Lc+ 60) 2 +Ic   (1)

a head moment of inertia about an axis parallel to the virtual axis of swing and passing through the center of gravity of the head defined as Ih (kg·cm 2 ); and
a head moment of inertia about the virtual axis of swing defined as Ihs (kg·cm 2 ) and calculated by the following formula (2):
Ih

Assignees

• Dunlop Sports Co Ltd

Inventors

• Nakamura Takashi

Classifications

• A63B53/00 Primary

  Golf clubs · CPC title

• A63B2209/023

  Long, oriented fibres, e.g. wound filaments, woven fabrics, mats · CPC title

• A63B60/42

  Devices for measuring, verifying, correcting or customising the inherent characteristics of golf clubs, bats, rackets or the like, e.g. measuring the maximum torque a batting shaft can withstand · CPC title

• A63B53/10

  Non-metallic shafts · CPC title

• A63B53/14

  Handles · CPC title