Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TITLE OF THE INVENTION
MULTIPLE MATERIAL GOLF CLUB HEAD
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a golf club head with a major body composed
of a metal
material, and a minor body composed of a light-weight material. More
specifically, the present
invention relates to a golf club head with a major body composed of a metal
material for a more
efficient transfer of energy to a golf ball at impact, and a non-metallic
minor body to control the
mass distribution.
Description of the Related Art
When a golf club head strikes a golf ball, large impacts are produced that
load the club
head face and the golf ball. Most of the energy is transferred h m the head to
the golf ball,
however, some energy is lost as a result of the collision. The golf ball is
typically composed of
polymer cover materials (such as ionomers) surrounding a rubber-like core.
These softer
polymer materials having damping (loss) properties that are strain and strain
rate dependent
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which are on the order of 10-100 times larger than the damping properties of a
metallic club face.
Thus, during impact most of the energy is lost as a result of the high
stresses and deformations
of the golf ball (0.001 to 0.20 inch), as opposed to the small deformations of
the metallic club
face (0.025 to 0.050 inch). A more efficient energy transfer from the club
head to the golf ball
could lead to greater flight distances of the golf ball.
The generally accepted approach has been to increase the stiffiiess of the
club head face to
reduce metal or club head deformations. However, this leads to greater
deformations in the golf
ball, and thus increases in the enerK, transfer problem.
Some have recognized the problem and disclosed possible solutions. An example
is
Campau, U.S. Patent Number 4,3 )98,965, for a Method Of Making Iron Golf Clubs
With Flexible
Impact Surface, which discloses a club having a flexible and resilient face
plate with a slot to
allow for the flexing of the face plate. The face plate of Campau is composed
of a ferrous
material, such as stainless steel, and has a thickness in the range of 0.1
inches to 0.125 inches.
Another example is Eggiman, U.S. Patent Number 5,863,261, for a Golf Club Head
With
Elastically Deforrning Face And Back Plates; whicti discloses the use of a
plurality of plates tihat
act in concert to create a spring-like effect on a golf ball durincr impact. A
fluid is disposed
between at least two of the plates to act as a viscous coupler.
Yet another example is Jepson et al, U.S. Patent Number 3,937,474, for a golf
Club With
A Polyurethane Insert. Jepson discloses that the polyurethane insert has a
hardness between 40
and 75 shore D.
Still another example is Inamori, U.S. Patent Number 3,975,023, for a Golf
Club Head
With Ceramic Face Plate, which discloses using a face plate composed of a
ceramic material
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having a high energy transfer coefficient, although ceramics are usually
harder materials. Chen
et al., U.S Patent Number 5,743,813 for a Golf Club Head, discloses using
multiple layers in the
face to absorb the shock of the golf ball. One of the materials is a non-metal
material.
Lu; U.S. Patent Number 5,499,814, for a Hollow Club Head With Deflecting
Insert Face
Plate, discloses a reinforcing element composed of a plastic or aluminum alloy
that allows for
minor deflecting of the face plate which has a thickness ranging from 0.01 to
0.30 inches for a
variety of materials including stainless steel, titanium, KEVLAR , and the
like. Yet another
Carnpau invention, U.S. Patent Number 3,989,248, for a Golf Club Having Insert
Capable Of
Elastic Flexing, discloses a wood club composed of wood with a metal insert.
Although not intended for flexing of the face plate, Viste, U.S. Patent Number
5,282,624
discloses a golf club head having a face plate composed of a forged stainless
steel material and
having a thickness of 3 mm. Anderson, U.S. Patent Number 5,344,140, for a Golf
Club Head
And Method Of Forming Same, also discloses use of a forged material for the
face plate. The
face plate of Anderson may be composed of several forged materials including
steel, copper and
titanium. T'ne forged plate has a uniform thickness of between 0.090 and 0.130
inches.
Another invention directed toward forged materials in a club head is Su et
al., U.S. Patent
Number 5,776,011 for a Golf Club Head. Su discloses a club head composed of
three pieces
with each piece composed of a forged material. The main objective of Su is to
produce a club
head with greater loft angle accuracy and reduce structural weaknesses.
Aizawa, U.S. Patent
Number 5,346,216 for a Golf Club Head, discloses a face plate having a curved
ball hitting
surface.
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U.S. Patent 6,146,571 to Vincent, et.al., discloses a method of manufacturing
a golf club
head wherein the walls are obtained by injecting a material such as plastic
over an insert affixed
to a meltable core. The core has a melt point lower than that of the
injectable plastic material so
that once the core is removed, an inner volume is maintained to form the inner
cavity. The insert
may comprise a resistance element for reinforcing the internal portion of the
front wall of the
shell upon removal of the core where the reinforcement element is comprised of
aluminum with
a laterally extending portion comprised of steel.
U.S. Patent 6,149,534 to Peters, et al., discloses a golf club head having
upper and lower
metal engagement surfaces formed along a single plane interface wherein the
metal of the lower
surface is heavier and more dense than the metal of the upper surface.
U.S. Patents 5,570,886 and 5,547,427 to Rigal, et al., disclose a golf club
head of molded
thermoplastic having a striking face defined by an impact-resistant metallic
sealing element. The
sealing element defines a front wall of the striking surface of the club head
and extends upward
and along the side of the impact surface to form a neck for attachment of the
shaft to the club
inead: 'f he sealing element preferably being berween 2.5 azid 5 nun in
thickness.
U.S. Patent 5,425,538 to Vincent, et al., discloses a hollow golf club head
having a steel
shell and a composite striking surface composed of a number of stacked woven
webs of fiber.
U.S. Patent 5,377,986 to Viollaz, et al., discloses a golf club head having a
body
composed of a series of metal plates and a hitting plate comprised of plastic
or composite
material wherein the hitting plate is imparted with a forwardly convex shape.
Additionally, U.S.
Patent 5,310,185 to Viollaz, et al., discloses a hollow golf club head having
a body composed of
a series of metal plates, a metal support plate being located on the front
hitting surface to which a
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hitting plate comprised of plastic or composite is attached. The metal support
plate has a
forwardly convex front plate associated with a forwardly convex rear plate of
the hitting plate
thereby forming a forwardly convex hitting surface.
U.S. Patent 5,106,094 to Desboilles, et al., discloses a golf club head having
a metal
striking face plate wherein the striking face plate is a separate unit
attached to the golf club head
with a quantity of filler material in the interior portion of the club head.
U.S. Patent 4,568,088 to Kurahashi discloses a wooden golf club head body
reinforced by
a mixture of wood-plastic composite material. The wood-plastic composite
material being
unevenly distributed such that a higher density in the range of between 5 and
15 mm lies adjacent
to and extends substantially parallel with the front face of the club head.
U.S. Patent 4,021,047 to Mader discloses a golf club wherein the sole plate,
face plate,
heel, toe and hosel portions are formed as a unitary cast metal piece and
wherein a wood or
composite crown is attached to this unitary piece thereby forming a hollow
chamber in the club
head.
U.S. Patent 5,624,331 to Lu, et al. discloses a hollow metai golf club head
where the
metal casing of the head is composed of at least two openings. The head also
contains a
composite material disposed within the head where a portion of the composite
material is located
in the openings of the golf club head casing.
U.S. Patent 1,167,387 to Daniel discloses a hollow golf club head wherein the
shell body
is comprised of metal such as aluminum alloy and the face plate is comprised
of a hard wood
such as beech, persinunon or the like. The face plate is aligned such that the
wood gain presents
endwise at the striking plate.
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U.S. Patent 3,692,306 to Glover discloses a golf club head having a bracket
with sole and
striking plates formed integrally thereon. At least one of the plates has an
embedded elongate
tube for securing a removably adjustable weight means.
U.S. Patent 5,410,798 to Lo discloses a method of manufacturing a composite
golf club
head using a metal casing to which a laminated member is inserted. A sheet of
composite
material is subsequently layered over the openings of the laminated member and
metal casing to
close off the openings in the top of both. An expansible pocket is then
inserted into the hollow
laminated member comprising sodium nitrite, ammonium chloride and water
causing.the
member to attach integrally to the metal casing when the head is placed into a
mold and heated.
U.S. Patent 4,877,249 to Thompson discloses a wood golf club head embodying a
laminated upper surface and metallic sole surface having a keel. In order to
reinforce the
laminations and to keep the body from delaminating upon impact with an
unusually hard object,
a bolt is inserted through the crown of the club head where it is connected to
the sole plate at the
keel and tightened to compress the taminations.
U.S. Patent 3,897,066 to Belmotit discloses a wooden golf club head having
rcz:,OvaiOiy
inserted weight adjustment members. The members are parallel to a central
vertical axis running
from the face section to the rear section of the club head and perpendicula=
to the crown to toe
axis. 1'he weight adjustment members may be held in place by the use of
capsules filled with
polyurethane resin, which can also be used to form the faceplate. The capsules
have openings on
a rear surface of the club head with covers to provide access to adjust the
weight means.
U.S. Patent 2,750,194 to Clark discloses a wooden golf club head with weight
adjustment
means. The cyolf club head includes a tray member with sides and bottom for
holding the weight
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adjustment preferably cast or formed integrally with the heel plate. The heel
plate with attached
weight member is inserted into the head of the golf club via an opening.
U.S. Patent 5,193,811 to Okumoto, et al. discloses a wood type club head body
comprised primarily of a synthetic resin and a metallic sole plate. The
metallic sole plate has on
its surface for bonding with the head body integrally formed members
comprising a hosel on the
heel side, weights on the toe and rear sides and a beam connecting the weights
and hosel.
Additionally, U.S. Patent 5,516,107 to Okumoto, et al., discloses a golf club
head having an
outer shell. preferably comprised of synthetic resin, and metal weight
member/s located on the
interior of the club head. A foamable material is injected into the hollow
interior of the club to
form the core. Once the foamable material has been injected and the sole plate
is attached, the
club head is heated to cause the foamable material to expand thus holding the
weight member/s
in position in recess/es located in toe, heel and/or back side regions by
pushing the weight
member into the inner surface of the outer shell.
U.S. Patent 4,872,685 to Sun discloses a wood type golf club head wherein a
female unit
is mated with a male anit to form a unitary golf club head. Tne fem.ale unit
comprises the upper
portion of the golf club head and is preferably composed of plastic, alloy, or
wood. The male
unit includes the structural portions of sole plate, a face insert consists of
the striking plate and
weighting elements. The male unit has a substantially geater weight being
preferably composed
of a light metal alloy. The units are mated or held together by bonding and or
mechanical means.
U.S. Patent 5,398,935 to Katayama discloses a wood golf club head having a
striking face
wherein the height of the striking face at a toe end of the golf club head is
nearly equal to or
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greater than the height of the striking face at the center of the club head.
U.S. Patent Number 1,780,625 to Mattem discloses a club head with a rear
portion
composed of a light-weight metal such as magnesium. U.S. Patent Number
1,638,916 to
Butchart discloses a golf club with a balancing member composed of persimmon
or a similar
wood material, and a shell-like body composed of aluminum attached to the
balancing member.
The Rules of Golf, established and interpreted by the United States Golf
Association
("USGA") and The Royal and Ancient Golf Club of Saint Andrews, set forth
certain
requirements for a golf club head. The requirements for a golf club head are
found in Rule 4 and
Appendix H. A complete description of the Rules of Golf are available on the
USGA web page
at www.usga.org. Although the Rules of Golf do not expressly state specific
parameters for a
golf club face, Rule 4-le prohibits the face from having the effect at impact
of a spring with a
golf ball. In 1998, the USGA adopted a test procedure pursuant to Rule 4-le
which measures
club face COR. This USGA test procedure, as well as procedures like it, may be
used to measure
club face COR.
iS Although the prior art has aisclosed many variations of multipie material
club hcads, the
prior art has failed to provide a multiple material club head with a high
moment of inertia and
geater forgiveness for the typical golfer.
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BRIEF SUMMARY OF THE INVENTION
The present invention provides a golf club with a golf club head having a
metal major
body and a light-weight minor body in order to provide a golf club head with a
high moment of
inertia and greater forgiveness. The golf club heads are preferably fairway
woods, having loft
angles greater than thirteen degrees, and ranging up to approximately twenty-
five degrees for an
eleven wood.
One aspect of the present invention is a golf club head including a major body
composed
of a metal material and a minor body composed of a non-metal material. The
major body has a
striking plate section, a return section, a sole section, a ribbon section and
a ledge section. The
striking plate section has a thickness in the range of 0.010 inch to 0.250
inch. The return section
has a thickness in the range of 0.010 inch to 0.200 inch. The minor body has a
crown section and
a ribbon section. The minor body is attached to the ledge section of the major
body.
Yet another aspect of the present invention is a golf club including a golf
club head and a
shatt. '1'he golf ciub head has a major body composed or a metai material and
a minor body
composed of a plurality of plies of pre-preg co-cured into a solid composite
shell. The major
body has a striking plate section, a return section, a sole section, a ribbon-
section and a ledge
section. The minor body has a crown section and a ribbon section. The minor
body is attached
to the ledge section of the major body. The golf club has a loft angle geater
than thirteen
degrees. The moment of inertia of the golf club head about the Izz axis
through the center of
gavity is greater than 1900 grams- centimeter squared, and the moment of
inertia about the Iyy
axis through the center of gravity is geater than 1000 grams- centimeter
squared.
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Having briefly described the present invention, the above and fiuther 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 front view of the golf club of the present invention.
FIG. 2 is a bottom view of the golf club head of FIG. 1.
FIG. 3 is rear side view of the golf club head of FIG. 1.
FIG. 4 is a toe side plan view of the golf club head of FIG. 1.
FIG. 5 is a top plan view of the golf club head of FIG. 1.
FIG. 6 is a heel side view of the golf club head of FIG. 1.
FIG. 7 is a top plan view of the golf club head of the present invention.
FIG. 8 is a cross-sectional view along line 8-8 of FIG. 7.
FIG. 8A is an isolated view of circle A of FIG. 8.
FIG. 8B is an isolated view of circle B of FIG. 8.
FIG. 9 is an exploded view of the components of the golf club head of the
present
invention.
FIG. 10 is a heel side plan view of a golf club of the present invention
illustrating the Z
axis and X axis.
FIG. l0A is a front plan view of a golf club of the present invention
illustrating the Z axis
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and Y axis.
FIG. 11 is a front plan view of a golf club of the present invention
illustrating the test
frame coordinates XT and YT and transformed head frarne coordinates YH and ZH.
FIG. 11A is a toe end view of the golf club of the present invention
illustrating the test
frame coordinate ZT and transformed head frame coordinates XH and ZH.
FIG. 12 is a front plane view of the golf club head of the present invention
illustrating the
variation in face thiclmess for one embodiment.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIGS. 1-9, a golf club is generally designated 30. The golf club
30 has a
golf club head 40 with a hollow interior, not shown. Engaging the club head 40
is a shaft 48 that
has agrip, not shown, at a butt end and is inserted into a hosel 54 at a tip
end.
The club head 40 is generally composed of two carrLponents, a major body 50
and minor
body 60. The minor body 60 has a crown section 62 and a ribbon section 64. The
club head 40
may also be partitioned into a heel end 66 nearest the shaft 48, a toe end 6-
8, opposite the heel
section 66, and an aft end 70.
The major body 50 is generally composed of a single piece of metal, and is
preferably
composed of a cast metal material. More preferably, the cast metal material is
a stainless steel
material or a titanium material such as pure titanium and titanium alloys such
as 6-4 titanium
alloy, SP-700 titanium alloy (available from Nippon Steel of Tokyo, Japan),
DAT 55G titanium
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alloy available from Diado Steel of Tokyo, Japan, Ti 10-2-3 Beta-C titanium
alloy available from
RTI International Metals of Ohio, and the like. Alternatively, the major body
may be
manufactured through forging, welding, forming, machining, powdered metal
forming, metal-
injection-molding, electro-chemical milling, and the like.
The major body 50 generally includes a striking plate section (also referred
to herein as a
face plate) 72, a return section 74 extending laterally rearward from the
upper perimeter of the
striking plate section 72, a sole section 76 extending laterally rearward from
the striking plate
section 72, a ribbon section 78 extending upward from the sole section 76, and
a ledge section 80
stepped inward for attachment of the minor body 60. The striking plate section
72 typically has a
plurality of scorelines thereon.
The return section 74 extends inward, towards the minor body 60, and has a
general
curvature from the heel end 66 to the toe end 68. The return section 74 has a
length from the
perimeter 73 of the striking plate section 72 that is preferably a minimal
length near the center of
the striking plate section 72, and increases toward the toe end 68 and the
heel end 66. A distance
d represents the length of the return section 74 from the perimeter 73 at the
cenicr u: the striking
plate section 72, a distance d' from the perimeter 73 at the heel end 66 of
the striking plate
section 72, and a distance d" from the perimeter 73 at the toe end 68 of
the,striking plate section
72. In a preferred embodiment, the distance d ranges from 0.2 inch to 1.0
inch, more preferably
0.30 inch to 0.75 inch, and most preferably 0.60 inch for a 3-wood golf club
head 40 and 0.35
inch for an eleven wood golf club head 40, as measured from the perimeter 73
of the striking
plate section 72 to the rearward edge of the return section 74. In a preferred
embodiment, the
distance d' ranges from 0.4 inch to 1.25 inch, more preferably 0.50 inch to
0.100 inch, and most
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preferably 0.8 inch, as measured from the perimeter 73 of the striking plate
section 72 to the
rearward edge of the return section 74. In a preferred embodiment, the
distance d" ranges from
0.4 inch to 1.25 inch, more preferably 0.50 inch to 0.100 inch, and most
preferably 0.9 inch, as
measured from the perimeter 73 of the striking plate section 72 to the
rearward edge of the return
section 74. The perimeter 73 of the striking plate section 72 is defined as
the transition point
where the major body 50 transitions from a plane substantially parallel to the
striking plate
section 72 to a plane substantially perpendicular to the striking plate
section 72. Alternatively,
one method for determining the transition point is to take a plane parallel to
the striking plate
section 72 and a plane perpendicular to the striking plate section 72, and
then take a plane at an
angle of forty-five degrees to the parallel plane and the perpendicular plane.
Where the forty-five
degrees plane contacts the major body 50 is the transition point thereby
defining the perimeter 73
of the striking plate section 72.
The minor body 60 is preferably composed of a non-metal material, preferably a
composite material such as continuous fiber pre-preg material (either
thermosetting resin or
tnermoplastic resin). Other materials for the uiinor body 60 include other
tiYermosetting
materials or other thermoplastic materials such as injection molded plastics.
The minor body 60
is preferably manufactured through bladder-molding, resin transfer molding,
resin infusion,
injection molding, compression molding, or a similar process. In a preferred
process, the major
body 50, with an adhesive on the exterior surface of the ledge section 80, is
press-fitted with the
minor body 60. Such adhesives include thermosetting adhesives in a liquid or a
film medium. A
preferred adhesive is a two part liquid epoxy sold by 3M of Minneapolis
Minnesota under the
brand names DP420NS and DP460NS. Other altemative adhesives include modified
acrylic
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liquid adhesives such as DP810NS, also sold by the 3M company. Alternatively,
foam tapes
such as Hysol Synspan may be utilized with the present invention.
As shown specifically in FIGS. 8A and 8B, the minor body 60 overlaps the ledge
section
80 a distance Lo, which preferably ranges from 0.10 inch to 1.00 inch, more
preferably ranges
from 0.40 inch to 0.70 inch, and is most preferably 0.50 inch. The ledge
section 80 is preferably
inward from the exterior surface of the major body 50 toward the hollow
interior 46 a distance Li
of 0.005 inch to 0.050 inch, more preferably 0.020 inch to 0.040 inch and most
preferably 0.035
inch. The edge 195 of the major body 50 determines the inward distance Li of
the ledge section
80. An annular gap 170 is created between an edge 190 of the minor body 60 and
the edge 195
of the major body 50. The annular gap 170 has a distance Lg that preferably
ranges from 0.020
inch to 0.100 inch, more preferably from 0.050 inch to 0.070 inch, and is most
preferably 0.060
inch. An optional projection from an exterior surface of the ledge section 80
may establish a
minimum bond thickness between the interior surface of the ledge section 80
and the overlapping
portion of the minor body 60. The bond thickness preferably ranges from 0.002
inch to 0.100
inch, more preferably ranges from 0.005 inch to 0.040 inch, and is most
preferabiy 0.0150 inch.
A liquid adhesive preferably secures the minor body 60 to the ledge section 80
of the major body
50.
The crown section 62 of the minor body 60 is generally convex toward the sole
section
76, and transitions into the ribbon section 64. The crown section 62
preferably has a thickness in
the range of 0.010 to 0.100 inch, more preferably in the range of 0.025 inch
to 0.070 inch, even
more preferably in the range of 0.028 inch to 0.040 inch, and most preferably
has a thickness of
0.033 inch. The ribbon section 64 preferably has a thickness in the range of
0.010 to 0.100 inch,
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more preferably in the range of 0.025 inch to 0.070 inch, even more preferably
in the range of
0.028 inch to 0.040 inch, and most preferably has a thickness of 0.033 inch.
In a preferred embodiment, the minor body 60 is composed of a plurality of
plies of pre-
preg, typically six or seven plies, such as disclosed in U.S. Patent Number
6,248,025, entitled
Composite Golf Head And Method Of Manufacturing.
The sole section 76 of the major body 50 is generally convex toward the crown
section
62. The sole section 76 alternatively has a recess for attachment of a sole
plate thereto. The sole
plate is preferably attached with a pressure sensitive adhesive such as a
polyethylene foam
acrylic adhesive sold by the 3M company. The sole plate is preferably composed
of a light
weight metal such as aluminum, titanium or titanium alloy. Alternatively, the
sole plate is
composed of a durable plastic material. The sole plate may have graphics
thereon for
designation of the brand of club and loft.
FIG. 9 illustrates the hollow interior 46 of the club head 42 of the present
invention. The
hosel 54 is disposed within the hollow interior 46, and is preferably integral
with the major
body 50. The hosel 54 is preferably cast with the major body 50. Additionally,
the hosel 54
may be composed of a non-similar material that is light weight and secured
using bonding or
other mechanical securing techniques. A hollow interior of the hosel 54 is
defined by a hosel
wall 120 that forms a tapering tube from the aperture 59 to the sole section
78. The shaft 48 is
disposed within a hosel insert 121 that is disposed within the hosel 54. Such
a hosel insert 121
and hosel 54 are described in U.S. Patent Number 6,352,482 issued on March 5,
2002, entitled
Golf Club With Hosel Liner.
As shown in FIG. 9, a rear weighting member 122 is preferably positioned
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hollow interior 46 of the club head 40. In a preferred embodiment, the rear
weighting member
122 is disposed on the interior surface of the ribbon section 73 in order to
increase the moment
of inertia and control the center of gravity of the golf club head 40. A heel
weighting member
123 is placed adjacent the hose154 on the interior surface of the sole section
76. However,
those skilled in the pertinent art will recognize that additional weighting
members may be
placed in other locations of the club head 40 in order to influence the center
of gravity, moment
of inertia, or other inherent properties of the golf club head 40. The
weighting members 122
and 123 are preferably weight chips thickened areas of the major body 50 or
weight chips
welded to the interior surface of the major body 50. Those skilled in the
pertinent art will
recognize that other high density materials may be utilized as an optional
weighting member
without departing from the scope and spirit of the present invention.
FIG. 12 illustrates the variation in the thickness of the striking plate
section 72. The
striking plate section 72 is preferably partitioned into elliptical regions,
each having; different
thickness. In a preferred embodiment for the striking plate section 72, the
striking plate section
72 has an central elliptical region 102 which preferably has the greatest
thickness that ranges
from 0.120 inch to 0.100 inch, preferably from 0.115 inch to 0.105 inch, and
is most preferably
0.111 inch. The central elliptical region 102 preferably has uniform
thickness. A first
concentric region 104 preferably has the next greatest thickness that ranges
from 0.110 inch to
0.090 inch, preferably from 0.104 inch to 0.094 inch. The first concentric
region 104 preferably
transitions in thickness kern 0.110 inch to 0.100 inch. A second concentric
region 106
preferably has the next
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greatest thickness that ranges from 0.100 inch to 0.080 inch, preferably from
0.095 inch to 0.085
inch. The second concentric region 106 preferably transitions in thickness
from 0'.100 inch to
0.090 inch. A third concentric region 108 preferably has the next greatest
thickness that ranges
from 0.090 inch to 0.070 inch, preferably from 0.083 inch to 0.073 inch. The
third concentric
region 108 preferably transitions in thiclaiess from 0.090 inch to 0.080 inch.
A 5rst periphery
region 110 preferably has the next geatest thickness that ranges from 0.085
inch to 0.061 inch.
The first periphery region 110 preferably transitions in thickness from 0.080
inch to 0.070 inch.
A second periphery region 112 preferably has a uniform thickness that ranges
from 0.050 inch to
0.080 inch, and most preferably 0.070 inch.
In an alternative embodiment, a central elliptical region 102 preferably has
the greatest
thickness that ranges from 0.120 inch to 0.100 inch, 'preferably from 0.115
inch to 0.105 inch,
and is most preferably 0.111 inch. The central elliptical region 102
preferably has uniform
thickness. A first concentric region 104 preferably has the next greatest
thickness that ranges
from 0.110 inch to 0.090 inch, preferably from 0.104 inch to 0.094 inch, and
is most preferably
0.099 inch. A periphery region 110 preferably has the next greatest thickness
that ranges from
0.069 inch to 0.061 inch. The variation in the thickness of the striking plate
section 72 allows for
the greatest thickness to be distributed in the center 111 of the striking
plate section 72 thereby
enhancing the flexibility of the striking plate section 72 which corresponds
to less energy loss to
a golf ball and a greater coefficient of restitution.
Preferably, the major body 50 is cast from molten metal in a method such as
the well-
known lost-wax casting method. The metal for casting is preferably 17-4
stainless steel.
Additional methods for manufacturing the major body 50 include forming the
major body 50
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from a flat sheet of metal, super-plastic forming the major body 50 from a
flat sheet of metal,
machining the major body 50 from a solid block of metal, electrochemical
milling the major
body 50 from a forged pre-form, and like manufacturing methods. Yet further
methods include
diffusion bonding titanium or steel sheets to yield a variable face thickness
face and then
superplastic forming.
The present invention is directed at a golf club head that has a high
coefficient of
restitution thereby enabling for greater distance of a golf ball hit with the
golf club head of the
present invention. The coefficient of restitution (also referred to herein as
"COR") is determined
by the following equation:
e = V.
Ut -U,
wherein U, is the club head velocity prior to impact; L~, is the ;olf ball
velocity prior to impact
which is zero; v f is the club head velocity just after separation of the golf
ball from the face of the
club head; v-, is the golf ball velocity just after separation of the golf
ball from the face of the club
head; and e is the coefficient of restitution between the golf ball and thG
eluu La(;e.
The values of e are limited between zero and 1.0 for systems with no energy
addition.
The coefficient of restitution, e, for a material such as a soft clay or
putty~would be near zero,
while for a perfectly elastic material, where no energy is lost as a result of
deformation, the value
of e would be 1Ø The present invention provides a club head having a
coefficient of restitution
ranging from 0.81 to 0.94, as measured under conventional test conditions.
The mass of the club head 40 of the present invention ranges from 165 grams to
250
grams, preferably ranges from 175 grams to 230 grams, and most preferably from
200 gams to
~s
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221 grams, with the three-wood golf club head 40 preferably having a mass of
203 grams and the
eleven-wood golf club head 40 preferably having a mass of 221 grams.
Preferably, the major
body 50 has a mass ranging from 140 grams to 200 grams, more preferably
ranging from 150
grams to 180 grams, yet more preferably from 155 grams to 166 grams, and most
preferably 161
grams. The minor body 60 has a mass preferably ranging from 4 grams to 20
grams, more
preferably from 5 grams to 15 grams, and most preferably 7 grams. The rear
weighting member
122 has a mass preferably ranging from 10 grams to 50 grams, more preferably
from 30 grams to
40 grams, and most preferably 31 grams. The heel weighting member 123 has a
mass preferably
ranging from 2 grams to 15 grams, more preferably from 3 grams to 10 grams,
and most
preferably 5gams. Additionally, epoxy, or other like flowable materials, in an
amount ranging
from 0.5 grams to 5 grams, may be injected into the hollow interior 46 of the
golf club head 40
for selective weighting thereof.
FIGS. 10 and l0A illustrate the axes of inertia through the center of gravity
of the golf
club head. The axes of inertia are designated X, Y and Z. The X axis extends
from the striking
plate section 72; through the center of gravity, CG, and to the rear of the
;olf club head 40. The
Y axis extends from the toe end 68 of the golf club head 40 through the center
of gravity, CG,
and to the heel end 66 of the golf club head 40. The Z axis extends from;the
crown section 62
through the center of gravity, CG, and to the sole section 76.
As defined in Golf Club Design, Fitting, Alteration & Repair, 4`h Edition, by
Ralph
Maltby, the center of gavity, or center of mass, of the golf club head is a
point inside of the club
head determined by the vertical intersection of two or more points where the
club head balances
when suspended. A more thorough explanation of this definition of the center
of gavity is
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CA 02385026 2008-11-24
club head determined by the vertical intersection of two or more points where
the club head
balances when suspended. A more thorough explanation of this definition of the
center of
gravity is provided in Golf Club Design, Fitting, Alteration & Repair.
The center of gravity and the moment of inertia of a golf club head 40 are
preferably
measured using a test flame (XT, YT, ZT), and then transformed to a head flame
(XH, Yx, ZH),
as shown in FIGS. 11 and 11A. The center of gravity of a golf club head may be
obtained using
a center of gravity table having two weight scales thereon, as disclosed in
U.S. Patent Number
6,607,452 issued August 19, 2003, entitled High Moment Of Inertia Composite
Golf Club.
In general, the moment of inertia, Izz, about the Z axis for the golf club
head 40 of the
present invention will range from 1900g-cm2 to 3000g-cm2, preferably from
1990g- m2 to
2500g-cm2, and most preferably from 1990g-cm2 to 2400g-cm2. The moment of
inertia, Iyy,
about the Y axis for the golf club head 42 of the present invention will range
from 900g-cm2 to
1700g-cm2, preferably from 950g-cm2 to 1500g-cm2, and most preferably from
965g-cm2 to
1200g-cm2. Table One list the moments of inertia for a 3-wood golf club head
40, a 7-wood
golf club head 40, 9-wood golf club head 40 and 11-wood golf club head 40.
Table One
Club lxx Iyy Izz
3 wood 1937 1110 2392
7 wood 1561 965 1995
9 wood 1577 991 2034
11 wood 1579 1001 2049
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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.
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