Note: Descriptions are shown in the official language in which they were submitted.
CA 02618319 2008-01-04
Docket No.: KMC-718
Inventors: David D. Jones
John K. Solheim
GOLF CLUB HEAD HAVING A FACE INSERT
AND METHOD OF MAKING SAME
BACKGROUND
[0001] This invention relates generally to golf equipment and, in particular,
to
golf clubs.
[0002] In order to improve the "feel" of golf clubs, especially putters, golf
manufacturers have frequently provided a face insert that forms the striking
face of the
club head. Early golf clubs had face inserts made of cork, wood, rubber, or
gutta-percha.
Recent golf clubs have face inserts made polymer resin, graphite epoxy and
polyurethane.
Examples of recent golf clubs with face inserts include U.S. Patent No.
5,575,472 to
Magerman et al, U.S. Patent No. 5,524,331 to Pond, U.S. Patent No. 5,458,332
to Fisher
and U.S. Patent Publication No. 2005/0020378 to Krumme et al.
SUMMARY
[0003] The present invention comprises a golf club. In one embodiment, the
golf
club includes a club head body, the front face of which has a cavity with a
first sub-cavity
and a second sub-cavity for receiving a first insert and a second insert,
respectively. The
cavity is defined by a bottom wall, a lower side wall, an upper side wall and
a platform
separating the lower and upper side walls. The first sub-cavity comprises a
lower portion
of the cavity located between the bottom wall and the platform, and the second
sub-cavity
comprises an upper portion of the cavity located between the platform and the
front face.
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A first insert is disposed in the first sub-cavity, and a second insert is
disposed in the
second sub-cavity. The first and second inserts are formed of different
materials.
DRAWINGS
[0004] FIG. 1 is a front exploded perspective view of a golf club head
according
to one embodiment of the present invention;
[0005] FIG. 2 is a front elevational view of the golf club head shown in FIG.
1;
[0006] FIG. 3 is a sectional view taken along lines 3-3 of FIG. 2; and
[0007] FIG. 4 is a sectional view of a golf club head in accordance with
another
embodiment of the present invention.
DESCRIPTION
[0008] With reference to FIGs. 1 and 2, a golf club head 10, such as a golf
putter head,
comprises a club head body 12 and a hosel 14 with a boss 16 counterbored for
receiving
one end of a golf club shaft 17. The body 12 has a front face 18, a rear
surface 19, a heel
end 20, and a toe end 22. The front face 18 has a cavity 24 formed therein
defined by a
bottom wall 26, a lower side wall 28, a platform 30, and an upper side wall
32. The
platform 30 separates the lower side wal128 and the upper side wall 32.
Platform 30 may
also be referred to as a step or a ledge. The lower side wall 28 is located
below the
platform 30 between the bottom wall 26 and the platform 30. The upper side
wall 32 is
located above the platform 30 between the platform 30 and the front face 18.
Protrusions
38 extend from upper side wall 32.
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[0009] A first sub-cavity 34 is defined between the bottom wall 26 and the
platform 30.
The first sub-cavity 34, or lower portion 34 of cavity 24, is circumscribed by
the lower
side wall 28. A second sub-cavity 36 is defined between the platform 30 and
the front
face 18. The second sub-cavity 36, or upper portion 36 of cavity 24, is
circumscribed by
the upper side wall 32. The first sub-cavity 34 has a smaller area than the
second sub-
cavity 36.
[00010] Typically, the club head body 12, including the cavity 24, is made of
a
material such as a metal formed by an investment casting process. Suitable
metals used
to form club head body 12 include steel, titanium, aluminum, tungsten, brass,
bronze,
beryllium copper, or the like. Those skilled in the art will recognize also
that the club
head body 12 may be made of other metallic or non-metallic materials. The
bottom wall
26, the lower side wall 28, the platform 30, the upper side wall 32, and the
protrusions 38
are then shaped by a milling process to maintain precise tolerances.
[00011] A first insert 44, also referred to as a damping insert, is disposed
in the
first sub-cavity 34. The damping insert 44 may be attached to the bottom wall
26 of the
first sub-cavity 34 using conventional means such as adhesive. The damping
insert 44 is
preferably made of a first polymer having a shore A hardness (durometer)
ranging from
about 25 to about 55. In this embodiment, the damping insert 44 may be
preformed by an
injection molding process in which an elastomeric polymer such as silicone is
injected
into a mold cavity. Alternatively, the damping insert 44 may be formed and
cured in the
first sub-cavity 34. Suitable materials for damping insert 44 include
silicone, silicone
dielectric gel, silicone rubber, or any other highly resilient elastomer.
After formation of
the damping insert 44, it is cured and inserted into the first sub-cavity 34
substantially
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covering the bottom wall 26 of the cavity 24. The damping insert 44 lies
adjacent the
lower side wall 28. By way of example, the damping insert 44 has a width "WD"
of
approximately 2.15 inches and a height "HD" of approximately 0.65 inches.
[00012] A second insert 46, also referred to as a face insert, is disposed in
the
second sub-cavity 36 above the platform 30 substantially covering the first
insert 44. The
face insert 46 may be attached to the first insert 44 and the platform 30
using
conventional means such as adhesive. The face insert 46 may be preformed of a
second
polymer having a shore D hardness ranging from about 45 to about 75.
Alternatively, the
face insert 46 may be formed and cured in the second sub-cavity 36. The face
insert 46 is
formed of a polymer that is different from that of the damping insert 44 and
different
from the material of the club head body 12. Preferably, the face insert 46
also has a
hardness (durometer) or resiliency that is different from that of the damping
insert 44. In
the illustrative embodiment, the face insert 46 is made of polyurethane, which
is molded
using an injection molding process and cured. After formation, the face insert
46 is
inserted into the second sub-cavity 36. The face insert 46 lies adjacent the
upper side
wall 32. The protrusions 38 position the face insert 46 in the second sub-
cavity 36 so that
a circumferential gap exists between the face insert 46 and the upper side
wall 32. This
circumferential gap will later be filled with material such as paint in order
to complete the
golf club head 10 as disclosed in U.S. Patent No. 6,913,545 to D. D. Jones et
al. By way
of example, the face insert 46 has a width "WF" of approximately 2.24 inches
and a
height "HF" of about 0.75 inches. The combined thickness of the damping insert
44 and
the face insert 46 is less than about 0.25 inches as measured between the
front face 18
and the bottom wall 26.
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[00013] FIG. 3 is a sectional view taken along lines 3-3 of FIG. 2 and further
illustrates the bottom wall 26, the lower side wall 28, the platform 30, and
the upper side
wall 32. Damping insert 44 is attached to bottom wall 26 and face insert 46 is
attached to
damping insert 44 and platform 30.
[00014] With reference to FIG. 4, in another embodiment, a club head body 12
has
a damping insert 50 disposed within the first sub-cavity 34. The damping
insert 50
comprises double-sided adhesive tape which is about 0.015 inches thick and cut
to a size
and shape that matches bottom wall 26. The damping insert 50 has adhesive
surfaces 52.
One of the adhesive surfaces 52 contacts or is attached to the bottom wall 26
of the first
sub-cavity 34. The face insert 46 is placed in the second sub-cavity 36 and
attached to
the other adhesive surface 52 of the damping insert 50. Alternatively, the
face insert 46
may injected onto an exposed surface 52 of the double-sided adhesive tape 50
and then
cured. In this embodiment, the face insert 46 is polymer with a Shore D
hardness when
cured.
