# US 10,864,413 B2 · Club head having balanced impact and swing performance characteristics

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- Number: US 10,864,413 B2
- Document ID: US10864413B2
- Status: Granted
- Kind: B2
- Application number: 16/747,384
- Filed: 2020-01-20
- Published: 2020-05-28
- Granted: 2020-12-15
- Earliest claimed: 2016-11-18
- Assignees: Karsten Manufacturing Corporation
- Applicants: Karsten Manufacturing Corporation
- Inventors: Ryan M. Stokke; Sina Ghods
- Web page: https://patentgrep.com/patent/US10864413B2

## CPC

- A63B 53/0466: {wood-type}
- A63B 53/0408: {characterised by specific dimensions, e.g. thickness}
- A63B 53/0412: {Volume}
- A63B 53/0433: {with special sole configurations}
- A63B 53/0437: {with special crown configurations}
- A63B 53/0445: {Details of grooves or the like on the impact surface}
- A63B 60/006: {Surfaces specially adapted for reducing air resistance}
- A63B 60/02: Ballast means for adjusting the centre of mass (A63B60/24, A63B60/54 take precedence)
- A63B 2053/0491: {with added weights, e.g. changeable, replaceable}
- A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H)

## Abstract

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.

## Claims

### Claim 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 between 12 degrees and 35 degrees;
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 FD when subjected to an air speed of 98 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 Ixx, a heel to toe
moment of inertia Iyy, 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 Ixx+Iyy;
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;
a maximum crown height greater than 0.30 inch, wherein the maximum crown height is measured as the greatest distance between the surface of the crown and the crown axis; and
the club head satisfies relation A and one or more of relations B and C:
A
.
⁢
F
D
+
0.3
0.0002
⁢
⁢
(
I
xx
+
I
yy
)
<
1
⁢
B
.
⁢
F
D
<
1.0
⁢
⁢
lbf
⁢
C
.
⁢
I
xx
+
I
yy
>
5000
⁢
⁢
g
·
cm
2
.

### Claim 2 (depends on 1)

The golf club head of claim 1, wherein the club head further satisfies relation D:
D
.
⁢
F
D
+
0.4
0.0002
⁢
⁢
(
I
xx
+
I
yy
)
<
1.

### Claim 3 (depends on 1)

The golf club head of claim 1, wherein the head CG depth is greater than 1.0 inches and the head CG height is less than 0.20 inches.

### Claim 4 (depends on 1)

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.

### Claim 5 (depends on 1)

The golf club head of claim 1, further comprising:
a clock grid having at least:
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; and
a 9 o'clock ray;
wherein:
the 12 o'clock ray is aligned with the geometric center of the strikeface and the clock grid is centered along the 12 o'clock ray at a midpoint between the front end and the back end of the club head;
the 3 o'clock ray extends towards the heel of the club head; and
the 9 o'clock ray extends towards the toe of the club head;
a weight structure located towards the sole and back end of the club head, the weight structure comprising a weight perimeter and a removable weight.

### Claim 6 (depends on 5)

The golf club head of claim 5, wherein the weight structure protrudes from an external contour of the sole.

### Claim 7 (depends on 5)

The golf club head of claim 5, wherein the weight structure comprises a removable weight having a weight center located between the 5 o'clock ray and the 8 o'clock ray of clock grid.

### Claim 8 (depends on 1)

The golf club head of claim 1, further comprises a crown angle less than 79 degrees, wherein the crown angle is measured as the acute angle between a front plane and a crown axis that extends through the crown transition point and the rear transition point of the club head.

### Claim 9 (depends on 1)

The golf club head of claim 1, further comprises 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.

### Claim 10

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 between 12 degrees and 35 degrees;
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 FD when subjected to an air speed of 98 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 Ixx, a heel to toe
moment of inertia Iyy, 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 Ixx+Iyy;
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;
a maximum crown height greater than 0.30 inch, wherein the maximum crown height is measured as the greatest distance between the surface of the crown and the crown axis; and
the club head satisfies relation A and one or more of relations B and C:
A
.
⁢
F
D
+
1.65
2
⁢
⁢
(
head
⁢
⁢
CG
⁢
⁢
depth
)
<
1
⁢
B
.
⁢
F
D
<
1.0
⁢
⁢
lbf
⁢
C
.
⁢
head
⁢
⁢
CG
⁢
⁢
depth
>
1.0
⁢
⁢
inches
.

### Claim 11 (depends on 10)

The golf club head of claim 10, wherein the club head further satisfies relation D:
⁢
D
.
⁢
F
D
+
1.8
2
⁢
⁢
(
head
⁢
⁢
CG
⁢
⁢
depth
)
<
1.

### Claim 12 (depends on 10)

The golf club head of claim 10, wherein the combined moment of inertia is greater than 5000 g·cm2.

### Claim 13 (depends on 10)

The golf club head of claim 10, further comprising one or more thin regions on the body having a thickness less than 0.02 inch.

### Claim 14 (depends on 10)

The golf club head of claim 10, further comprising:
a clock grid having at least:
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; and
a 9 o'clock ray;
wherein:
the 12 o'clock ray is aligned with the geometric center of the strikeface and the clock grid is centered along the 12 o'clock ray at a midpoint between the front end and the back end of the club head;
the 3 o'clock ray extends towards the heel of the club head; and
the 9 o'clock ray extends towards the toe of the club head;
a weight structure located towards the sole and back end of the club head, the weight structure comprising a weight perimeter and a removable weight.

### Claim 15 (depends on 14)

The golf club head of claim 14, wherein the weight structure protrudes from an external contour of the sole.

### Claim 16 (depends on 14)

The golf club head of claim 14, wherein the weight structure comprises a removable weight having a weight center located between the 5 o'clock ray and the 8 o'clock ray of clock grid.

### Claim 17 (depends on 10)

The golf club head of claim 10, further comprises a crown angle less than 79 degrees, wherein the crown angle is measured as the acute angle between a front plane and a crown axis that extends through the crown transition point and the rear transition point of the club head.

### Claim 18 (depends on 10)

The golf club head of claim 10, further comprises 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.

### Claim 19 (depends on 10)

The golf club head of claim 10, wherein the combined moment of inertia is greater than 5,300 g·cm2.

### Claim 20 (depends on 10)

The golf club head of claim 10, wherein the combined moment of inertia is greater than 5,600 g·cm2.