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, 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, 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 at a head CG height from a head depth plane, measured in a direction perpendicular to the head depth plane;
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 I xx , a heel to toe
moment of inertia I yy , and a combined moment of inertia measured
as the sum of the crown-to-sole moment of inertia and the heel to toe moment of inertia I xx +I yy ;
wherein the combined moment of inertia is greater than 9000 g·cm2;
further comprising an embedded weight comprising a weight center position at one or more of the following locations:
(a) within 0.5 inch of a perimeter of the club head;
(b) greater than 2.2 inches from the head center of gravity; or
(c) greater than 4.0 inches from the geometric center of the strikeface; and
the club head satisfies relation A and one or more of relations B and C:
F
D
+
1.9
2.1
(
head
CG
depth
)
<
1
A
F
D
<
1.15
lbf
B
head
CG
depth
>
1.65
inches
.
C
2. The golf club head of claim 1 , wherein the club head further satisfies relation D:
F
D
+
2.8
2.1
(
head
CG
depth
)
<
1.
D
3. The golf club head of claim 1 , wherein the combined moment of inertia is greater than 10,000 g·cm 2 .
4. The golf club head of claim 1 , further comprising one or more thin regions on the body having a thickness less than 0.02 inch.
5. 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 the 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.
6. 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 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 I xx , a heel to toe
moment of inertia I yy , and a combined moment of inertia measured
as the sum of the crown-to-sole moment of inertia and the heel to toe moment of inertia I xx +I yy ;
further comprising an embedded weight comprising a weight center position at one or more of the following locations:
(a) within 0.5 inch of a perimeter of the club head;
(b) greater than 2.2 inches from the head center of gravity; or
(c) greater than 4.0 inches from the geometric center of the strikeface; and
the club head satisfies relation A and one or more of relations B and C:
F
D
+
2.7
0.0005
(
I
xx
+
I
yy
)
<
1
A
F
D
<
1.15
lbf
B
I
xx
+
I
yy
>
9000
g
·
cm
2
.
C
7. The golf club head of claim 6 , wherein the club head further satisfies relation D:
F
D
+
3.8
0.0005
(
I
xx
+
I
yy
)
<
1.
D
8. The golf club head of claim 6 , wherein the head CG depth is greater than 1.2 inches.
9. The golf club head of claim 6 , further comprising one or more thin regions on the body having a thickness less than 0.02 inch.
10. The golf club head of claim 6 , 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 the 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.
11. The golf club head of claim 6 , wherein the combined moment of inertia is greater than 10,000 g·cm 2 .
12. 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 depth is greater than 1.2 inches; and
the head CG height is less than 0.20 inches;
a crown-to-sole moment of inertia is greater than 3000 g·cm 2 ;
a heel-to-toe moment of inertia is greater than 5000 g·cm 2 ; and
the club head experiences a drag force less than 1.4 lbf 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 further comprising an embedded weight comprising a weight center position at one or more of the following locations:
(a) within 0.5 inch of a perimeter of the club head;
(b) greater than 2.2 inches from the head center of gravity; or
(c) greater than 4.0 inches from the geometric center of the strikeface.
13. The golf club head of claim 12 , wherein the club head experiences a drag force less than 1.15 lbf 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.
14. The golf club head of claim 12 , further comprising one or more thin regions on the body having a thickness less than 0.02 inch.
15. The golf club head of claim 12 , 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 the 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.
16. The golf club head of claim 12 , wherein the combined moment of inertia is greater than 10,000 g·cm 2 .