Information
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Patent Grant
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6348013
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Patent Number
6,348,013
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Date Filed
Thursday, December 30, 199924 years ago
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Date Issued
Tuesday, February 19, 200222 years ago
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Inventors
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Original Assignees
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Examiners
Agents
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CPC
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US Classifications
Field of Search
US
- 473 345
- 473 346
- 473 324
- 473 329
- 473 349
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International Classifications
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Abstract
A compliant golf club head permits a more efficient impact between a golf ball and the golf club head. By allowing a face section of the golf club head to flex rearwardly during impact with the golf ball internal stresses within the golf ball are reduced to yield a more efficient impact. A thin wall section is located generally parallel with the face and near the junction with a top, bottom heel and toe sections to allow the face of the golf club head to flex rearwardly.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a golf club head. More specifically, the present invention relates to a compliant face section of a golf club head to reduce energy losses when impacting a golf ball.
2. Description of the Related Art
Technical innovation in the material, construction and performance of golf clubs has resulted in a variety of new products. The advent of metals as a structural material has largely replaced natural wood for wood-type golf club heads, and is but one example of this technical innovation resulting in a major change in the golf industry. In conjunction with such major changes are smaller scale refinements to likewise achieve dramatic results in golf club performance. For example, the metals comprising the structural elements of a golf club head have distinct requirements according to location in the golf club head. A sole or bottom section of the golf club head should be capable of withstanding high frictional forces for contacting the ground. A crown or top section should be lightweight to maintain a low center of gravity. A front or face of the golf club head should exhibit high strength and durability to withstand repeated impact with a golf ball. While various metals and composites are known for use in the face, several problems arise from the use of homogeneous and non-homogeneous face structure.
A non-homogeneous face structure typically involves an insert centrally located which requires an exacting fit between two or more distinct elements, but has the advantage of utilizing beneficial material properties in a combination which is not available in each material individually. A homogeneous face structure is simpler to manufacture but is limited to the inherent material properties of one material. The present invention achieves the performance advantages of a non-homogeneous face structure with a simpler homogeneous construction.
BRIEF SUMMARY OF THE INVENTION
The present invention comprises an improved structure to reduce energy loss during impact of a golf club head with a golf ball. In a preferred embodiment the golf club head is a wood-type golf club head with a plurality of walls to define a hollow interior. During impact both the golf club head and the golf ball will compress, followed by the golf ball leaving the face of the golf club head where both the golf club head and the golf ball will experience a decaying vibration mode before returning to their respective original shapes. By allowing the golf club head to flex and “cradle” the golf ball during impact the internal stress in the golf ball is reduced, leading to a longer duration and more energy conserving impact. Extending the contact time of the golf ball with the face of the golf club reduces energy lost in the golf ball. By producing an channel or recess in one or more walls of the golf club head the contact time of the golf ball will increase as the linear distance the face travels during impact is increased. This channel defines a thin or minimum wall thickness in one or more sections of the golf club head. The face of the golf club head can be constructed from rigid material and still obtain the benefits of the present invention.
Shape and location of the recess determines important performance variables including durability, coefficient of restitution (COR) and angular deflection. Walls of the recess should be smoothly contoured to accommodate bending stresses from golf ball impact while allowing the face to move rearwardly in the golf club head without altering the face orientation.
Coefficient of restitution (COR) is well known to those of ordinary skill in the art, and is defined as the ratio of the of the golf ball velocity over the golf club head velocity, where velocity is measured before and just after impact of the golf ball with the golf club head.
Expressed mathematically, the equation is outlined below:
where V
2 ball
is the velocity of the golf ball measured immediately after impact with the golf club head; V
1 ball
is the velocity of the golf ball measured immediately before impact with the golf club head; V
1 club head
is the velocity of the golf club head measured immediately before impact with the golf ball; V
2 club head
is the velocity of the golf club head measured immediately after impact with the golf club head.
One object of the present invention is to improve impact efficiency between a golf club head and the golf ball.
Another object is to allow a rigid material to perform as a compliant golf club face. Any number of rigid materials can be utilized in the manufacture of the golf club of the present invention to produce a compliant, or softer flexing performance during impact with the golf ball.
A further object of the present invention is a wood-type golf club head having an internal channel for flexing of the golf club face.
Another object of the present invention is a wood-type golf club head having an external channel for flexing of the golf club face.
Another object of the present invention is a golf club head comprising a face cup containing a channel.
Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1
is a perspective view of a golf club head of an embodiment of the present invention.
FIG. 2
is an exploded cross-sectional toe view along lines II—II of
FIG. 1
, illustrating a face cup with an annular channel and a body for attachment to the face cup of an embodiment of the present invention.
FIG. 3
is a front view of a face of an embodiment of the present invention with dashed lines representing the channel in the perimeter of the golf club head.
FIG. 4
a
is an enlarged view of section IV of
FIG. 2
illustrating smooth contours for the channel of an embodiment of the golf club head of the present invention.
FIG. 4
b
is an enlarged view of section IV of
FIG. 2
illustrating sharper contours for the channel than
FIG. 4
a
of an embodiment of the golf club head of the present invention.
FIG. 4
c
is an enlarged view of section IV of
FIG. 2
illustrating a small radius contour for the channel of an embodiment of a golf club of the present invention.
FIG. 5
a
is a cross-sectional toe view along lines II—II of
FIG. 1
, illustrating a golf club head of an embodiment of the present invention prior to impact with the golf ball.
FIG. 5
b
represents the golf club head of an embodiment of the present invention during initial impact with the golf ball.
FIG. 5
c
represents the golf club of an embodiment of the present invention when fully deflected during impact with the golf ball.
FIG. 6
is a toe view of an alternative embodiment of the present invention having the channel displaced toward the rear of the golf club head.
FIG. 7
is a toe view of another alternative embodiment of the present invention having the channel located on the exterior of the golf club head.
DETAILED DESCRIPTION OF THE INVENTION
Like numbers are used throughout the detailed description to designate corresponding parts of a golf club head of the present invention.
As shown in
FIG. 1
a wood-type golf club head
10
comprises a face section
12
, a rear section
14
, a top section
16
, a bottom section
18
, a toe section
20
, a heel section
22
and a hosel inlet
24
to accept a golf shaft (not shown). The golf club head
10
is a unitary structure which may be composed of two or more elements joined together to form the golf club head
10
. Structural material for the golf club head
10
can be selected from metals and non-metals, with metals such as stainless steel and titanium being preferred embodiments. The face section
12
is an impact surface for contacting a golf ball
38
(not shown).
FIG. 2
is an embodiment of the present invention where the golf club head
10
is formed from the combination of a face cup
26
and a body cup
28
, wherein the structural material for the face cup
26
and the body cup
28
may be the same or different. A channel or recess
30
is present on the interior of the face cup
26
in a ceiling surface
32
, a wall surface
34
and a floor surface
36
to allow the face section
12
to act as a compliant surface. In other words, a relatively stiff material can behave as a more flexible material by employing the channels
30
of the present invention. The face section
12
is allowed to flex rearwardly toward the rear section
14
during impact with a golf ball. This action reduces the internal stress concentration within the golf ball, resulting in a more efficient momentum transfer from the golf club head
10
to the golf ball.
FIG. 3
is a front view of an embodiment of the present invention where the face section
12
of the golf club head
10
is shown in relation to the channel
30
. Dotted lines indicate the channel
30
is located on the interior surface
32
and not visible from the exterior of the golf club head
10
.
FIGS. 4
a-c
are enlarged views of section IV as shown in
FIG. 2
, and indicate various contours and locations for the channel
30
.
FIG. 4
a
illustrates the channel recess
30
located primarily toward the wall surface
34
and having a width w.
FIG. 4
b
illustrates the channel
30
encompassing both the ceiling surface
32
and the wall surface
34
, while having a narrowed width w than
FIG. 4
a
.
FIG. 4
c
illustrates the channel recess
30
located primarily toward the ceiling surface
32
and having a narrow width w.
FIGS. 5
a-c
depict an impact of the golf club
10
with the golf ball
38
. In
FIG. 5
a
the golf club head
10
appears prior to impact, with the channel
30
located at approximately the intersection of the face section
12
with the top section
16
, the bottom section
18
, the toe section
20
(not shown) and the heel section
22
(not shown). It is understood that the channel
30
can be located on or slightly rearward of the face section
12
and is not limited to the location illustrated in
FIG. 5
a-c
. Initial contact of the golf ball
38
with the golf club
10
is shown in
FIG. 5
b
where the face section
12
is shown as deflecting toward the rear section
14
. Channel
30
acts as a hinge to facilitate the deflection of the face section
12
. Maximum deflection of the face section
12
is shown in
FIG. 5
c
, after which the face section
12
will return to original shape as depicted in
FIG. 5
a
and the golf ball
38
will separate from the golf club head
10
.
FIGS. 6 and 7
represent alternative embodiments of the present invention wherein the channel
30
may be located at various locations on or near the face section
12
. The channel
30
can be located toward the rear section
14
as illustrated in
FIG. 6
, or on an exterior surface as illustrated in FIG.
7
.
From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims.
Claims
- 1. A metal wood-type golf club head comprising:a face cup having a face section and a rear section extending laterally rearwardly from the face section, the rear section having an interior ceiling surface and floor surface, the face section being of relatively equal thickness in all directions, wherein the ceiling surface of the rear section has a first channel therein and the floor surface of the rear section has a second channel therein whereby the first channel and the second channel allow the face section greater flexibility upon impact with a golf ball wherein said first and second channels being a minimum wall thickness compared to a wall thickness of either side of said first and second channels; and a body cup having a top section, a bottom section, a toe section, and a heel section, the body cup joined to the rear section of the face cup.
US Referenced Citations (44)