Club head having balanced impact and swing performance characteristics
Described herein are embodiments of golf club heads having a balance of the following parameters: a low and back club head center of gravity position, a high moment of inertia, a large Ixy product of inertia, and low aerodynamic drag. Methods of manufacturing the embodiments of golf club heads having a balance of club head center of gravity position, moment of inertia, product of inertia, and aerodynamic drag are also described herein.
1. A hollow body golf club head comprising:
a body having a front end, a back end opposite the front end, a crown, a sole opposite the crown, a heel, a toe opposite the heel, a skirt adjoining the crown and the sole, and a hosel structure having a hosel axis extending centrally through a bore in the hosel structure;
a strikeface positioned at the front end and defining a geometric center, a loft plane tangent to the geometric center, and a head depth plane extending through the geometric center from the heel to the toe, perpendicular to the loft plane;
wherein:
a loft angle of the club head is less than 16 degrees;
a volume of the club head is greater than 400 cc;
a head center of gravity of the club head is located at a head CG depth from the loft plane, measured in a direction perpendicular to the loft plane, and a head CG height from a head depth plane, measured in a direction perpendicular to the head depth plane;
the head CG height is less than 0.20 inches;
a y-axis extending through the head center of gravity from the crown to the sole;
an x-axis extending through the head center of gravity from the heel to the toe, wherein the x-axis is perpendicular to the y-axis;
the club head experiences a drag force F d when subjected to an air speed of 102 mph in a direction perpendicular to a plane extending through the geometric center of the strikeface, parallel to the hosel axis, and positioned at the loft angle from the loft plane;
the club head has a crown to sole moment of inertia Iyy, and a heel to toe moment of inertia Ixx, and a product of inertia Ixy about the x-axis and y-axis;
wherein the product of inertia is at greater than 100 g·cm 2 ;
the club head satisfies relation A and relation B:
Ixy
Ixx
·
Iyy
>
4
.
4
5
×
1
0
-
5
A
.
F
d
<
1.15
lbf
.
B
.
2. The golf club head of claim 1 , wherein the club head further satisfies relation C:
A
+
(
4
.
7
5
×
1
0
-
7
)
(
3.24
·
10
-
5
)
·
(
CG
height
)
>
1
.
C
.
3. The golf club head of claim 1 , wherein the club head further satisfies relation D:
A
+
(
7
.
5
0
×
1
0
-
6
)
(
1
.
5
1
×
1
0
-
5
)
·
(
F
d
)
>
1
.
D
.
4. The golf club head of claim 1 , wherein the head CG depth is greater than 1.3 inches.
5. The golf club head of claim 1 , further comprises:
a 12 o'clock ray;
a 3 o'clock ray;
a 4 o'clock ray;
a 5 o'clock ray;
a 8 o'clock ray;
a 9 o'clock ray;
a 10 o'clock ray; and
an 11 o'clock ray;
when the golf club head is at an address portion, from a bottom view of the golf club head, the 12 o'clock ray is aligned with the strikeface geometric center and orthogonal to a front intersection line between the loft plane and a ground plane;
a clock grid is centered along the 12 o'clock ray, at a midpoint between the front end of the head and the rear end of the head;
the 3 o'clock ray extends towards the heel;
the 9 o'clock ray extends towards the toe;
a first embedded weight and a second embedded weight;
wherein the first embedded weight can be located near the toe and crown, at least partially bounded between the 11 o'clock ray and 9 o'clock ray of the clock grid, as well as intersecting the 10 o'clock ray; and
wherein the second embedded weight can be located near the heel and the sole, at least partially bounded between the 3 o'clock ray and 5 o'clock ray of the clock grid, as well as intersecting the 4 o'clock ray.
6. The golf club head of claim 5 , wherein;
the first and second embedded weights comprise tungsten.
7. The golf club head of claim 1 , wherein the Iyy moment of inertia is greater than 4500 g·cm 2 .
8. The golf club head of claim 1 , wherein a combined moment of inertia is greater than 7250 g·cm 2 .
9. The golf club head of claim 1 , further comprising:
a front radius of curvature between 0.18 to 0.30 inch, wherein the front radius of curvature extends from a top edge of the strikeface to a crown transition point, the crown transition point indicating a change in curvature from the front radius of curvature to a different curvature of the crown; and
a rear radius of curvature that extends between the crown and the skirt of the club head along a rear transition boundary from a first rear transition point located at a junction between the crown and the rear transition boundary and a second rear transition point located at the junction between the rear transition boundary and the skirt of the club head.
10. The golf club head of claim 9 , further comprising:
a crown angle less than 79 degrees, wherein the crown angle is measured as an acute angle between a front plane and a crown axis that extends through the crown transition point and a rear transition point of the club head; and
a maximum crown height greater than 0.50 inch, wherein the maximum crown height is measured as a greatest distance between a surface of the crown and the crown axis.
11. A hollow body golf club head comprising:
a body having a front end, a back end opposite the front end, a crown, a sole
opposite the crown, a heel, a toe opposite the heel, a skirt adjoining the crown and the sole, and a hosel structure having a hosel axis extending centrally through a bore in the hosel structure;
a strikeface positioned at the front end and defining a geometric center, a loft plane tangent to the geometric center, and a head depth plane extending through the geometric center from the heel to the toe, perpendicular to the loft plane;
wherein:
a loft angle of the club head is less than 16 degrees;
a volume of the club head is greater than 400 cc;
a head center of gravity of the club head is located at a head CG depth from the loft plane, measured in a direction perpendicular to the loft plane, and at a head CG height from a head depth plane, measured in a direction perpendicular to the head depth plane;
the head CG height is less than 0.20 inches;
a y-axis extending through the head center of gravity from the crown to the sole;
an x-axis extending through the head center of gravity from the heel to the toe, wherein the x-axis is perpendicular to the y-axis;
the club head experiences a drag force Fd when subjected to an air speed of 102 mph in a direction perpendicular to a plane extending through the geometric center of the strikeface, parallel to the hosel axis, and positioned at the loft angle from the loft plane;
the club head has a crown to sole moment of inertia Iyy, and a heel to toe moment of inertia Ixx, and a product of inertia Ixy about the x-axis and y-axis;
wherein the product of inertia is at greater than 100 g·cm2;
the club head has a strike face to skirt moment of inertia Izz, and a heel to toe moment of inertia Ixx, and a product of inertia Ixz about a z-axis and about the x-axis;
the club head satisfies relation A:
Ixz
Ixx
·
Izz
>
-
1
.
3
6
×
1
0
-
5
.
A
.
12. The golf club head of claim 11 , wherein the club head further satisfies relation D:
A
-
(
1
.
1
2
×
1
0
-
4
)
(
9
.01
·
10
-
5
)
·
(
CG
depth
)
>
1
.
B
.
13. The golf club head of claim 11 , wherein the club head further satisfies relation C:
A
-
(
9
.
2
3
×
1
0
-
5
)
(
6
.
9
9
×
1
0
-
5
)
·
(
F
d
)
>
1.
C
.
14. The golf club head of claim 11 , wherein the club head further satisfies relation D:
F d <1.15 lb. D.
15. The golf club head of claim 11 , wherein the head CG depth is greater than 1.3 inches.
16. The golf club head of claim 11 , further comprises:
a 12 o'clock ray;
a 3 o'clock ray;
a 4 o'clock ray;
a 5 o'clock ray;
a 8 o'clock ray;
a 9 o'clock ray;
a 10 o'clock ray; and
an 11 o'clock ray;
when the golf club head is at an address portion, from a bottom view of the golf club head, the 12 o'clock ray is aligned with the strikeface geometric center and orthogonal to a front intersection line between the loft plane and a ground plane;
a clock grid is centered along the 12 o'clock ray, at a midpoint between the front end of the head and the rear end of the head;
the 3 o'clock ray extends towards the heel; and
the 9 o'clock ray extends towards the toe;
a first embedded weight and a second embedded weight;
wherein the first embedded weight can be located near the toe and crown, at least partially bounded between the 11 o'clock ray and 9 o'clock ray of the clock grid, as well as intersecting the 10 o'clock ray; and
wherein the second embedded weight can be located near the heel and the sole, at least partially bounded between the 3 o'clock ray and 5 o'clock ray of the clock grid, as well as intersecting the 4 o'clock ray.
17. The golf club head of claim 16 , wherein;
the first and second embedded weights comprise tungsten.
18. The golf club head of claim 11 , wherein a combined moment of inertia is greater than 7250 g·cm 2 .
19. The golf club head of claim 11 , further comprising:
wherein the Ixz is greater −160 g·cm 2 .
20. The golf club head of claim 11 , wherein the Iyy moment of inertia is greater than 4500 g·cm 2 .