Note: Descriptions are shown in the official language in which they were submitted.
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
1
Title
GOLF CLUB HEAD
Technical Field
The present invention relates to a golf club head. More specifically,
the present invention relates to a golf club head having a substantially
square
or substantially rectangular configuration.
Background Art
When a golf club head strikes a golf ball, large impacts that load the
club head face and the golf ball are produced. Most of the energy is
transferred from 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 have damping (loss) properties that are strain and strain
rate
dependent, 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 theyolf 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 stiffness 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
energy
transfer problem.
Some have recognized the problem and disclosed possible solutions.
One example is Campau, U.S. Patent Number 4,398,965, 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 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
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
2
Golf Club Head With Elastically Deforming Face And Back Plates, which
discloses the use of a plurality of plates that act in concert to create a
spring-
like effect on a golf ball during 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 a face plate
composed of a ceramic material having a high energy transfer coefficient,
although ceramics are usually harder materials. Cheri 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 deflection 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 Campau 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 flexion 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 the 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. The forged plate has a uniform thickness of
between 0.090 and 0.130 inch.
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
3
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 reduced 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.
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
head. The sealing element preferably being between 2.5 and 5 mm 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.
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
4
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 Number
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 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 Number 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 Number 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 is 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 Number 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 Number 5,624,331 to Lo, et al. discloses a hollow metal
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 Number 1,167,387 to Daniel discloses a hollow golf club
head wherein the shell body is comprised ofinetal such as aluminum alloy and
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
the face plate is comprised of a hard wood, such as beech, persimmon or the
like. The face plate is aligned such that the wood grain presents endwise at
the
striking plate.
U.S. Patent Number 3,692,306 to Glover discloses a golf club head
5 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 Number 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 Number 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 laminations.
U.S. Patent Number 3,897,066 to Belmont discloses a wooden golf
club head having removably 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 perpendicular to the crown to toe axis.
The 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 Number 2,750,194 to Clark discloses a wooden golf club
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
6
head with weight adjustment means. The golf club head includes a tray
member with sides and bottom for holding the weight 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 Number 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/s into the inner surface of the outer
shell.
U.S. Patent Number 4,872,685 to Sun discloses a wood type golf club
head wherein a female unit is mated with a male unit to form a unitary golf
club head. The female 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 greater weight and
is preferably composed of a light metal alloy. The units are mated or held
together by bonding and or mechanical means.
U.S. Patent Number 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 greater than the height of the
striking
face at the center of the club head.
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
7
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.
U.S. Patent Number 3,981,507 to Nunziato discloses a cube-like club
head to provide a rectangular face.
U.S. Patent Number 2,336,405 to Kent discloses a golf club with a
trapezoidal shaped club head.
U.S. Patent Number D226,431 to Baker discloses a design for a club
head with a greater rear-wall.
U.S. Patent Number 3,397,888 to Springer et al., discloses a putter
head with a rectangular shape.
U.S. Patent Number 3,486,755 to Hodge discloses a putter with a
triangular-like shape.
U.S. Patent Number 3,901,514 discloses a putter with a club head
shaped like a ring.
U.S. Patent Number D179,002 to Hoffineister discloses a design for a
club head with a circular face and an elongated body.
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. One such limitation is the volume of the golf club head.
Existing large volume driver heads (>400cc) composed of conventional
materials (titanium, steel) and conventional manufacturing methods (casting,
forging, MIM, machining, etc.) are limited in the amount of discretionary
material available for increasing the moments of inertia of the golf club
head.
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
8
Conventional golf club head shapes also limit the moments of inertia possible
for any given volume golf club head.
Summary of the Invention
One aspect of the present invention is a golf club head having a
substantially square configuration and a moment of inertia, Izz, about the
center of gravity of the golf club head that exceeds 4000 grams-centimeter
squared. The golf club head may be a multi-material golf club head including
a metallic face component and a non-metallic aft-body component that is
bonded to the face component.
Another aspect of the present invention is a golf club head with a body
having a front wall, a crown wall, a sole wall, a heel wall, an aft wall, and
a toe
wall, in which the body has a volume ranging from 350 cubic centimeters to
500 cubic centimeters and each of the aft wall, the toe wall and the heel wall
is
substantially straight.
The golf club head preferably has a geometric center point, an aft-heel
edge point and an aft-toe edge point, in which the distance from the geometric
center point to the aft-heel edge point is equal to the distance from the
geometric center point to the aft-toe edge point. The golf club head may also
include an aft-heel curvature section between the aft wall and the heel wall,
and an aft-toe curvature section between the aft wall and the toe wall. Each
of
the aft-heel curvature section and the aft-toe curvature section preferably
has a
curvature length ranging from 0.5 inch to 1.0 inch. The heel wall preferably
extends rearward from a perimeter of the front wall a distance of least 50% of
the length of the heel wall at an angle of 80 degrees to 90 degrees relative
to a
plane parallel to the farthest extent of the face. The distance from the
geometric center point to the aft-heel edge point and the distance from the
geometric center point to the aft-toe edge point are preferably the greatest
lengths of the geometric center point to a location on the golf club head.
Still another aspect of the invention is a golf club head with a body
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
9
having a face wall, a crown wall, a sole wall, a heel wall, a rear wall, and a
toe
wall. The golf club head has a volume ranging from 350 cubic centimeters to
500 cubic centimeters and a mass ranging from 190 grams to 250 grams.
More than 50% of the volume of the golf club head is forward of the center of
gravity of the golf club head and less than 50% of the mass of the golf club
head is forward of the center of gravity. Forward of the center of gravity of
the
golf club head is toward the face wall.
Yet another aspect of the invention is a golf club head with a more
consistent coefficient of restitution ("COR") across the striking plate of the
golf club head than other golf club heads. More specifically, the golf club
head of the present invention has a lower standard of deviation of COR across
the striking plate than other golf club heads. In particular, the golf club
head
of the present invention has a volume ranging from 350 cubic centimeters to
500 cubic centimeters, a mass ranging from 190 grams to 250 grams, and a
standard deviation of COR of less than 0.226.
Another aspect of the invention is a golf club head with a body having
a face wall, a crown wall, a sole wall, a heel wall, a rear wall, and a toe
wall.
The golf club head has a volume ranging from 350 cubic centimeters to 500
cubic centimeters and a mass ranging from 190 grams to 250 grams. The golf
club head has a delta of the coefficient of restitution between a geometric
face
center of the face wall and a location 0.5 inch sole-ward from the face center
is
less than 0.65.
Brief Description of the Drawings
FIG. 1 is a perspective view of a golf club head of the present
invention.
FIG. lA is a front view of a golf club of the present invention.
FIG. 2 is a front view of the club head of FIG. 1.
FIG. 2A is a front view of the club head of FIG. 1 illustrating a
plurality of preferred hit locations.
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
FIG. 3 is a heel side view of the club head of FIG. 1.
FIG. 3A is a heel side view of the club head of FIG. 1.
FIG. 4 is a toe side view of the club head of FIG. 1.
FIG. 5 is a rear plan view of the club head of FIG. 1.
5 FIG. 6 is a top plan view of the club head of FIG. 1.
FIG. 6A is a top plan view of the club head of FIG. 1.
FIG. 7 is a bottom plan view of the club head of FIG. 1.
FIG. 8 is a top plan view of a club head of the prior art.
FIG. 9 is a bottom plan view of the club head of FIG. 8.
10 FIG. 10 is a perspective view of a preferred embodiment of the golf
club head of the present invention.
FIG. 11 is a front view of the club head of FIG. 10.
FIG. 12 is a heel side view of the club head of FIG. 10.
FIG. 13 is a toe side view of the club head of FIG. 10.
FIG. 14 is a rear plan view of the club head of FIG. 10.
FIG. 15 is a top plan view of the club head of FIG. 10.
FIG. 16 is a bottom plan view of the club head of FIG. 10.
FIG. 17 is a top plan view of a club head of the present invention
illustrating the wall angles relative to each other.
FIG. 18 is a bottom plan view of a club head of the present invention
illustrating the wall angles relative to each other.
FIG. 19 is a bottom plan view of a club head of the present invention
illustrating the wall angles relative to each other.
FIG. 20 is a top plan view of a club head of the present invention
illustrating the wall angles relative to each other.
FIG. 21 is a top plan view of a club head of the present invention
illustrating the wall angles relative to each other.
FIG. 22 is a front view of an alternative embodiment of a golf club
head of the present invention.
FIG. 23 is a top plan view of the club head of FIG. 22.
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
11
FIG. 24 is a bottom plan view of the club head of FIG. 22.
FIG. 25 is a rear plan view of the club head of FIG. 22.
FIG. 26 is a heel side view of the club head of FIG. 22.
FIG. 27 is a toe side view of the club head of FIG. 22.
FIG. 28 is a front view of another alternative embodiment of a golf
club head of the present invention.
FIG. 29 is a top plan view of the club head of FIG. 28.
FIG. 30 is a bottom plan view of the club head of FIG. 28.
FIG. 31 is a rear plan view of the club head of FIG. 28.
FIG. 32 is a heel side view of the club head of FIG. 28.
FIG. 33 is a toe side view of the club head of FIG. 28.
FIG. 34 is a front view of still another alternative embodiment of a golf
club head of the present invention.
FIG. 35 is a top plan view of the club head of FIG. 34.
FIG. 36 is a bottom plan view of the club head of FIG. 34.
FIG. 37 is a rear plan view of the club head of FIG. 34.
FIG. 38 is a heel side view of the club head of FIG. 34.
FIG. 39 is a toe side view of the club head of FIG. 34.
FIG. 40 is an isolated interior view of a face component for a golf club
head of the present invention.
FIG. 41 is an isolated bottom plan view of the face component of FIG.
40.
FIG. 42 is an isolated toe side view of the face component of FIG. 40.
Best Mode(s) for Carrying Out the Invention
The present invention is generally directed at a golf club head that has
a substantially square or rectangular shape when viewed from the top or
bottom (as opposed to a side view) and has a relatively high moment of inertia
Izz about the center of gravity of the golf club head. A general embodiment of
the club head is illustrated in FIGS. 1-7. A preferred embodiment of the club
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
12
head is illustrated in FIGS. 10-16. An alternative embodiment of the club
head is illustrated in FIGS. 22-27. A second alternative embodiment of the
club head is illustrated in FIGS. 28-33. A third alternative embodiment of the
club head is illustrated in FIGS. 34-39. Although five embodiments are
illustrated, those skilled in the pertinent art will recognize from this
disclosure
that other embodiments of the golf club head of the present invention are
possible without departing from the scope and spirit of the present invention.
As shown in FIGS. 1-7, a golf club head of the present invention is
generally designated 42. Preferably, a body 43 of the golf club head has a
crown 62', a sole 64', a ribbon 90', and a striking plate 72', all of which
preferably define a hollow interior. The golf club head 42 has a heel end 66,
a
toe end 68 an aft end 70.
The golf club head 42, when designed as a driver, preferably has a
volume from 200 cubic centimeters to 600 cubic centimeters, more preferably
from 300 cubic centimeters to 500 cubic centimeters, and most preferably
from 420 cubic centimeters to 470 cubic centimeters, with a most preferred
volume of 460 cubic centimeters. The volume of the golf club head 42 will
also vary between fairway woods (preferably ranging from 3-woods to eleven
woods) with smaller volumes than drivers.
The golf club head 42, when designed as a driver, preferably has a
mass no more than 215 grams, and most preferably a mass of 180 to 215
grams. When the golf club head 42 is designed as a fairway wood, the golf
club head preferably has a mass of 135 grams to 200 grams, and preferably
from 140 grams to 165 grams.
As shown in FIG. 1A, a golf club 40 has a substantially square golf
club head 42. Engaging the club head 42 is a shaft 48 that has a grip 50 at a
butt end 52 of the shaft 48 and is inserted into a hosel 54 of the club head
42 at
a tip end 56 of the shaft 48.
The club head 42 has a heel wall 166, a toe wall 168 and a rear wall
170, all of which are substantially straight relative to each other and the
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
13
striking plate 72' of the club head 42. Further, each of the heel wall 166,
the
toe wall 168 and the rear wall 170 is substantially straight when compared to
the walls of a prior art club head shown in FIGS. 8 and 9.
As shown in FIG. 3, the heel wall 166 has a distance, "Dhw", from a
perimeter 73 of the striking plate 72' to a furthest rearward extent of the
club
head 42 that preferably ranges from 2.00 to 5.00 inches, more preferably from
3.0 to 4.5 inches, and most preferably from 3.5 to 4.0 inches.
As shown in FIG. 4, the toe wall 168 has a distance, "Dtw", from a
perimeter 73 of the striking plate 72' to a furthest rearward extent of the
club
head 42 that preferably ranges from 2.00 to 5.00 inches, more preferably from
3.0 to 4.5 inches, and most preferably from 3.5 to 4.0 inches.
As shown in FIG. 5, the rear wall 170 has a distance, "Daw", from a
widest extent of the heel end 66 of the club head to a widest extent of the
toe
end 68 of the club head 42 that preferably ranges from 2.50 to 5.50 inches,
more preferably from 3.0 to 4.75 inches, and most preferably from 4.0 to 4.5
inches.
In one embodiment, the distances Dhw, Dtw and Daw are all equal in
length ranging from 3.5 to 4.25 inches. In an alternative embodiment, the
distances Dhw and Dtw are equal in length ranging from 2.5 to 4.0 inches.
As shown in FIG. 6, a geometric center of the club head 42 is
designated "GC." The geometric center is defined as the center based on the
geometry of the club head 42. A distance "Dgh" from the geometric center to
an aft-heel edge point 150 ranges from 1.5 inches to 3.5 inches, and more
preferably from 2.0 inches to 3.0 inches, and is most preferably 2.5 inches. A
distance "Dgt" from the geometric center to an aft-toe edge point 155 ranges
from 1.5 inches to 3.5 inches, and more preferably from 2.0 inches to 3.0
inches, and is most preferably 2.5 inches. In a preferred embodiment, the
distances Dgh and Dgt are the farthest distances of any point on the club head
42 from the geometric center. In an alternative embodiment, the distances Dgh
and Dgt are at least equal to the farthest distances of any point on the club
head
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
14
42 from the geometric center. The aft-heel edge point 150 is defined as the
inflection point along the edge of the heel wall 166 and the rear wall 170
wherein the heel wall 166 transitions to the rear wall 170. The aft-toe edge
point 155 is defined as the inflection point along the edge of the toe wall
168
and the rear wall 170 wherein the toe wall 168 transitions to the rear wall
170.
As shown in FIG. 6, the club head 42 has an aft-heel curvature section
200 and an aft-toe curvature section 205. The aft-heel curvature section 200
is
the transition from the heel wall 166 to the rear wall 170. The aft-toe
curvature section 205 is the transition from the toe wall 168 to the rear wall
170. The club head 42 of the present invention has a reduced curvature section
as compared to club head 42x of the prior art.
As shown in FIG. 6A, the golf club head 42 has a length, Lg,h, from a
farthest forward edge 777 of the golf club head 42 to a farthest rearward edge
747 of the golf club head 42 that preferably ranges from 3.0 inches to 5.0
inches, more preferably 3,5 inches to 4.75 inches, even more preferably 4.0
inches to 4.5 inches, and most preferably about 4.15 inches. In a preferred
embodiment, the center of gravity CG of the golf club head 42 is positioned
less than 50% of the length, Lg,h, from the farthest forward edge 777. The
center of gravity CG is even more preferably positioned from 30% to 49% of
the length from the farthest forward edge 777. In a preferred embodiment, due
to the loft angle of the face of the golf club head 42, the farthest forward
edge
777 is at a junction of the face wall (striking plate) 72' and sole wall 64'
of the
golf club head 42. The farthest rearward edge 747 is preferably on the ribbon
90'.
As shown in FIG. 3A, the golf club head 42 has a height, Hxch, from a
topmost portion 787 of the crown 62' of the golf club head 42 to a bottommost
portion 797 of the sole 64' of the golf club head 42 that preferably ranges
from
2.0 inches to 3.0 inches, and more preferably from 2.25 inches to 2.75 inches,
and is most preferably about 2.60 inches. The center of gravity CG of the golf
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
club head 42 is preferably positioned less than 50% of the height, Hg~h, from
the bottommost portion 797 of the sole 64' of the golf club head 42', and more
preferably is positioned from 40% to 49% of the height, Hg~h, from the
bottommost portion 797 of the sole 64' of the golf club head 42.
5 As shown in FIGS. 3A and 6A, dashed line 555 represents an
imaginary plane that separates the golf club head 42 into a section that is
forward of the center of gravity CG and rearward of the center of gravity CG.
The golf club head 42 is unique in that preferably more than 50% of the
volume of the golf club head 42 is forward of the center of gravity CG of the
10 golf club head 42 and preferably less than 50% of the mass of the golf club
head 42 is forward of the center of gravity CG. Stated in another manner,
preferably less than 50% of the volume of the golf club head 42 is rearward of
the center of gravity CG of the golf club head 42 and preferably more than
50% of the mass of the golf club head 42 is rearward of the center of gravity
15 CG. Stated in yet another manner, preferably more than 50% of the volume of
the golf club head 42 is forward of the center of gravity CG of the golf club
head 42 and preferably more than 50% of the mass of the golf club head 42 is
rearward of the center of gravity CG. Most preferably, 35% to 46% of the
mass of the golf club head 42 is forward for the center of gravity CG. Most
preferably 51 % to 65% of the volume of the golf club head 42 is forward of
the center of gravity CG.
As shown in FIG. 7, the heel wall 166 has a distance, "Dhw' ", from a
perimeter 73 of the striking plate 72' to the aft-heel edge point 150 that
preferably ranges from 2.00 to 4.5 inches, more preferably from 2.5 to 4.25
inches, and most preferably from 3.0 to 4.0 inches.
As shown in FIG. 7, the toe wall 168 has a distance, "Dtw' ", from a
perimeter 73 of the striking plate 72' to the aft-toe edge point 155 that
preferably ranges from 2.00 to 4.5 inches, more preferably from 2.5 to 4.25
inches, and most preferably from 3.0 to 4.0 inches.
As shown in FIG. 7, the rear wall 170 has a distance, "Daw' ", from the
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
16
aft-heel edge point 150 to the aft-toe edge point 155 that preferably ranges
from 2.50 to 5.00 inches, more preferably from 3.0 to 4.0 inches, and most
preferably from 3.25 to 3.75 inches. In a preferred embodiment, the distances
Dhw' and Dtw' are equal in length ranging from 2.5 to 4.0 inches.
In a preferred embodiment, the club head 42 is generally composed of
two components, a face component 60, and an aft-body 61, as shown in FIGS.
10-16. The aft-body 61 preferably has a crown portion 62 and a sole portion
64.
The face component 60 is generally composed of a single piece of
metal, and is preferably composed of a forged metal material. More
preferably, the forged metal material is a forged titanium material. Such
titanium materials include 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 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. Other metals for the face component 60 include stainless
steel, other high strength steel alloy metals and amorphous metals.
Alternatively, the face component 60 is manufactured through casting,
forming, machining, powdered metal forming, metal-injection-molding,
electro chemical milling, and the like.
The face component 60 generally includes a striking plate portion (also
referred to herein as a face plate) 72 and a return portion 74 extending
laterally
inward from a perimeter 73 of the striking plate portion 72. The striking
plate
portion 72 typically has a plurality of scorelines 75 thereon. The striking
plate
portion 72 preferably has a thickness ranging from 0.010 inch to 0.250 inch,
and the return portion 74 preferably has a thickness ranging from 0.010 inch
to
0.250 inch. The return portion 74 preferably extends a distance ranging from
0.25 inch to 1.5 inches from the perimeter 73 of the striking plate portion
72.
In a preferred embodiment, the return portion 74 generally includes an
upper lateral section 76, a lower lateral section 78, a heel lateral section
80 and
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
17
a toe lateral section 82. Thus, the return 74 preferably encircles the
striking
plate portion 72 a fu11360 degrees. However, those skilled in the pertinent
art
will recognize that the return portion 74 may only encompass a partial section
of the striking plate portion 72, such as 270 degrees or 180 degrees, and may
also be discontinuous.
The upper lateral section 76 preferably extends inward, towards the aft-
body 61, a predetermined distance, d, to engage the crown 62. In a preferred
embodiment, the predetermined distance d ranges from 0.2 inch to 1.2 inch,
more preferably 0.40 inch to 1.0 inch, and most preferably 0.8 inch, as
measured from the perimeter 73 of the striking plate portion 72 to the
rearward
edge of the upper lateral section 76. In a preferred embodiment, the upper
lateral section 76 is substantially straight and substantially parallel to the
striking plate portion 72 from the heel end 66 to the toe end 68.
The perimeter 73 of the striking plate portion 72 is preferably defined
as the transition point where the face component 60 transitions from a plane
substantially parallel to the striking plate portion 72 to a plane
substantially
perpendicular to the striking plate portion 72. Alternatively, one method for
determining the transition point is to take a plane parallel to the striking
plate
portion 72 and a plane perpendicular to the striking plate portion, 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 face
component is the transition point thereby defining the perimeter of the
striking
plate portion 72.
The heel lateral section 80 is substantially perpendicular to the striking
plate portion 72, and the heel lateral section 80 preferably covers a portion
of
the hosel 54 before engaging an optional ribbon section 90 and a bottom
section 91 of the sole portion 64 of the aft-body 61. The heel lateral section
80
is attached to the sole portion 64, both the ribbon section 90 and the bottom
section 91, as explained in greater detail below. The heel lateral section 80
extends inward a distance, d, from the perimeter 73 a distance of 0.2 inch to
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
18
1.2 inch, more preferably 0.40 inch to 1.0 inch, and most preferably 0.8 inch.
The heel lateral section 80 is preferably straight at its edge.
At the other end of the face component 60 is the toe lateral section 82.
The toe lateral section 82 is preferably attached to the sole 64, both the
ribbon
90 and the bottom section 91, as explained in greater detail below. The toe
lateral section 82 extends inward a distance, d, from the perimeter 73 a
distance of 0.2 inch to 1.2 inch, more preferably 0.40 inch to 1.0 inch, and
most preferably 0.8 inch. The toe lateral section 82 preferably is preferably
straight at its edge.
The lower lateral section 78 extends inward, toward the aft-body 61, a
distance, d, to engage the sole portion 64. In a preferred embodiment, the
distance d ranges from 0.2 inch to 1.2 inch, more preferably 0.40 inch to 1.0
inch, and most preferably 0.8 inch, as measured from the perimeter 73 of the
striking plate portion 72 to the edge of the lower lateral section 78.
The aft-body 61, which is attached to the face component 60 but
separated therefrom by a gap 105, is preferably composed of a non-metal
material, preferably a composite material such as continuous fiber pre-preg
material (including thermosetting materials or a thermoplastic materials for
the
resin). Other materials for the aft-body 61 include other thermosetting
materials or other thermoplastic materials such as injectable plastics. In the
alternative, the aft-body 61 is composed of low-density metal materials, such
as magnesium or aluminum. Exemplary magnesium alloys are available from
Phillips Plastics Corporation under the brands AZ-91-D (nominal composition
of magnesium with aluminum, zinc and manganese), AM-60-B (nominal
composition of magnesium with aluminum and manganese) and AM-50-A
(nominal composition of magnesium with aluminum and manganese). The
aft-body 61 is preferably manufactured through metal-injection-molding.
Alternatively, the aft-body 61 is manufactured through casting, forming,
machining, powdered metal forming, electro chemical milling, and the like.
The aft-body 61 is preferably manufactured through bladder-molding,
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
19
resin transfer molding, resin infusion, injection molding, compression
molding, or a similar process. In a preferred process, the face component 60,
with an adhesive on the interior surface of the return portion 74, is placed
within a mold with a preform of the aft-body 61 for bladder molding. 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 alternative
adhesives include modified acrylic 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.
A bladder is placed within the hollow interior of the preform and face
component 60, and is pressurized within the mold, which is also subject to
heating. The co-molding process secures the aft-body 61 to the face
component 60. Alternatively, the aft-body 61 is bonded to the face component
60 using an adhesive, or mechanically secured to the return portion 74.
The crown portion 62 of the aft-body 61 is generally convex toward the
sole 64, and engages the ribbon section 90 of sole portion 64 outside of the
engagement with the face member 60. The crown portion 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 sole
portion 64, including the bottom section 91 and the optional ribbon section
90,
which is substantially perpendicular to the bottom section 91, 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. In a preferred
embodiment, the aft-body 61 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,
which is hereby incorporated by reference in its entirety.
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
The hosel 54 is preferably at least partially disposed within the hollow
interior of the club head 42, and is preferably located as a part of the face
component 60. The hosel 54 is preferably composed of a similar material to
the face component 60, and is preferably secured to the face component 60
5 through welding or the like. Alternatively, the hosel 54 may be formed with
the formation of the face component 60.
In a preferred embodiment, a weight member 122 is preferably
positioned on the aft body 61 to increase the moment of inertia of the club
head 42, to influence the center of gravity, or influence other inherent
10 properties of the golf club head 42. The weight member 122 is preferably
composed of tungsten loaded film, tungsten doped polymers, or similar
weighting mechanisms such as described in U.S. Patent Number 6,386,990,
filed on December 29, 1999, entitled A Composite Golf Club Head With An
Integral Weight Strip, and hereby incorporated by reference in its entirety.
15 Those skilled in the pertinent art will recognize that other high density
materials, such as lead-free pewter, may be utilized as an optional weight
without departing from the scope and spirit of the present invention.
In a preferred embodiment two weight members 122a and 122b are
embedded within the plies of pre-preg of the ribbon section 90 of the sole
20 portion 64 of the aft-body 61. Individually, each weight member 122 has a
mass ranging from 5 grams to 30 grams. Each weight member 122 is
preferably composed of a material that has a density ranging from 5 grams per
cubic centimeters to 20 grams per cubic centimeters, more preferably from 7
grams per cubic centimeters to 12 grams per cubic centimeters.
Each weight member 122 is preferably composed of a polymer material
integrated with a metal material. The metal material is preferably selected
from copper, tungsten, steel, aluminum, tin, silver, gold, platinum, or the
like.
A preferred metal is tungsten due to its high density. The polymer material is
a thermoplastic or thermosetting polymer material. A preferred polymer
material is polyurethane, epoxy, nylon, polyester, or similar materials. A
most
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
21
preferred polymer material is a thermoplastic polyurethane. A preferred
weight member 122 is an injection molded thermoplastic polyurethane
integrated with tungsten to have a density of 8.0 grams per cubic centimeters.
In a preferred embodiment, each weight member 122 is composed of from 50
to 95 volume percent polyurethane and from 50 to 5 volume percent tungsten.
Also, in a preferred embodiment, each weight member 122 is composed of
from 10 to 25 weight percent polyurethane and from 90 to 75 weight percent
tungsten.
Preferably, the weight members 122a and 122b are positioned in the
aft-heel corner and the aft-toe corner of the golf club head 42, generally
corresponding to the aft-heel edge point 150 and the aft-toe edge point 155.
Those skilled in the pertinent art will recognize that other weighting
materials
may be utilized for the weight member 122 without departing from the scope
and spirit of the present invention. The placement of the weight members
122a and 122b allows for the moment of inertia of the golf club head 42 to be
optimized.
As shown in FIGS. 40-42, the face component has a striking plate
portion 72 with varying thicknesses, wherein portion 72a is thicker than
portion 72b, which is thicker than portion 72c. In a preferred embodiment, the
striking plate portion 72 has a varying thickness such as described in U.S
Patent Number 6,398,666, for a Golf Club Striking Plate With Variable
Thickness, which pertinent parts are hereby incorporated by reference. Other
alternative embodiments of the thickness of the striking plate portion 72 are
disclosed in U.S. Patent Number 6,471,603, for a Contoured Golf Club Face
and U.S. Patent Number 6,368,234, for a Golf Club Striking Plate Having
Elliptical Regions Of Thickness, which are both owned by Callaway Golf
Company and which pertinent parts are hereby incorporated by reference.
Alternatively, the striking plate portion 72 has a uniform thickness.
As mentioned previously, the face component 60 is preferably forged
from a rod of metal material. One preferred forging process for manufacturing
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
22
the face component is set forth in U.S. Patent Number 6,440,011, filed on
April 13, 2000, entitled Method For Processing A Striking Plate For A Golf
Club Head, and hereby incorporated by reference in its entirety.
Alternatively,
the face component 60 is cast from molten metal in a method such as the well-
known lost-wax casting method. The metal for forging or casting is preferably
titanium or a titanium alloy such as 6-4 titanium alloy, alpha-beta titanium
alloy or beta titanium alloy for forging, and 6-4 titanium for casting.
Additional methods for manufacturing the face component 60 include
forming the face component 60 from a flat sheet of metal, super-plastic
forming the face component 60 from a flat sheet of metal, machining the face
component 60 from a solid block of metal, electrochemical milling the face
from a forged pre-form, and like manufacturing methods. Yet further methods
include diffusion bonding titanium sheets to yield a variable face thickness
face and then superplastic forming.
Alternatively, the face component 60 is composed of an amorphous
metal material such as disclosed in U.S. Patent Number 6,471,604, which was
filed on April 4, 2002 and is hereby incorporated by reference in its
entirety.
An alternative embodiment of a club head 42 with a face component 60
and aft-body 61 is shown in FIGS. 22-27. In this embodiment, the club head
42 has a plurality of external weights 122a' and 122b' positioned on the aft-
body 61. Another alternative embodiment of a club head 42 with a face
component 60 and aft-body 61 is shown in FIGS. 28-33. Yet another
alternative embodiment of a club head 42 with a face component 60 and aft-
body 61 is shown in FIGS. 34-39. In this embodiment, the bottom section 91
of the sole portion 64 has a sole inward curvature 333 which creates a first
keel
point 275 and a second keel point 277 of the club head 42.
In an alternative embodiment of the golf club head 42 of FIGS. 1-7, the
body 43 has a front wall with an opening in which a striking plate 72' is
preferably disposed within the opening. The body 43 is preferably composed
of a non-metal material, preferably a composite material such as a continuous
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
23
fiber pre-preg material (including thermosetting materials or thermoplastic
materials for the resin). Other materials for the body 43 include other
thermosetting materials or other thermoplastic materials such as injectable
plastics. Further, other materials for the body 43 include magnesium alloys,
aluminum alloys, magnesium, aluminum or other low density metals. The
body 43 is preferably manufactured through bladder-molding, resin transfer
molding, resin infusion, injection molding, compression molding, or a similar
process.
The striking plate insert 72' is attached to the body 43 over the opening
of the front wall of the body 43. The striking plate insert 72' is preferably
composed of a formed metal material. Alternatively the striking plate insert
72' is composed of a machined metal material, a forged metal material, a cast
metal material or the like. The striking plate insert 72' preferably is
composed
of a formed titanium or steel material. A preferred material is steel 4340,
which is heat treated and then coated with a titanium nitride. Titanium
materials useful for the striking plate insert 40 include 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 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. Other metals for the striking
plate insert 40 include other high strength steel alloy metals and amorphous
metals. Such steel materials include 17-4PH, Custom 450, 455, 465 and 465+
stainless steels, AERMET 100 and AERMET 310 alloy steels, all available
from Carpenter Specialty Alloys, of Pennsylvania, and C35 maraging steels
available from Allvac of North Carolina. Such amorphous metals include
beryllium based alloys such as disclosed in U.S. Patent Number 5,288,344,
which pertinent parts are hereby incorporated by reference, quinary metallic
glass alloys such as disclosed in U.S. Patent Number 5,735,975, which
pertinent parts are hereby incorporated by reference, and ternary alloys as
disclosed in Calculations of Amorphous-Forming Composition Range For
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
24
Ternary Alloy Systems And Analyses Of Stabilization OfAmorphous Phase
And Amorphous-Forming Ability, Takeuchi and Inoue, Materials Transactions,
Vol. 42, No. 7, p 1435-1444 (2001), which pertinent parts are hereby
incorporated by reference.
The striking plate insert 72' is preferably co-molded with a body 43 or
press-fitted into the opening subsequent to fabrication of the body 43. In
another attachment process, the body 43 is first bladder molded and then the
striking plate insert 72' is bonded to a recessed portion of the front wall
using
an adhesive. The adhesive is placed on the exterior surface of the recessed
portion. 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 alternative adhesives include modified acrylic 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.
Yet another embodiment of the golf club head 42 shown in FIGS. 1-7,
the body 43 is preferably composed of a metal material such as titanium,
titanium alloy, or the like, and is most preferably composed of a cast
titanium
alloy material.
The body 43 is preferably cast from molten metal in a method such as
the well-known lost-wax casting method. The metal for casting is preferably
titanium or a titanium alloy such as 6-4 titanium alloy, alpha-beta titanium
alloy or beta titanium alloy for forging, and 6-4 titanium for casting.
Alternatively, the body 43 is composed of 17-4 steel alloy. Additional
methods for manufacturing the body 43 include forming the body 43 from a
flat sheet of metal, super-plastic forming the body 43 from a flat sheet of
metal, machining the body 43 from a solid block of metal, electrochemical
milling the body from a forged pre-form, casting the body using centrifugal
casting, casting the body using levitation casting, and like manufacturing
methods.
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
The golf club head 42 of this embodiment optionally has a front wall
with an opening for placement of a striking plate insert 72' such as disclosed
in U.S. Patent Number 6902497 for A Golf Club Head With A Face Insert.
The striking plate insert 72' preferably is composed of a formed titanium
alloy
5 material. Such titanium materials include titanium alloys such as 6-22-22
titanium alloy and Ti 10-2-3 alloy, Beta-C titanium alloy, all available from
RTI International Metals of Ohio, SP-700 titanium alloy (available from
Nippon Steel of Tokyo, Japan), DAT 55G titanium alloy available from Diado
Steel of Tokyo, Japan, and like materials. The preferred material for the
10 striking plate insert 72' is a heat treated 6-22-22 titanium alloy which is
a
titanium alloy composed by weight of titanium, 6% aluminum, 2% tin, 2%
chromium, 2% molybdenum, 2% zirconium and 0.23% silicon. The titanium
alloy will have an alpha phase in excess of 40% of the overall microstructure.
In a preferred embodiment, the striking plate insert 72' has uniform
15 thickness that ranges from 0.040 inch to 0.250 inch, more preferably a
thickness of 0.080 inch to 0.120 inch, and is most preferably 0.108 inch for a
titanium alloy striking plate insert 72'.
In yet another embodiment for the golf club head 42 shown in FIGS. 1-
7, the golf club head has a construction with a crown composed of plies of pre-
20 preg material such as disclosed in U.S. patent Number 6,575,845, for a
Multiple Material Golf Club Head, which pertinent parts are hereby
incorporated by reference.
In yet another embodiment, the golf club head 42 has a shape as
disclosed, particularly as shown in FIGS.1-7, and a construction with a body
25 composed of plies of pre-preg material such as disclosed in U.S. Patent
Number 6,607,452, for a High Moment Of Inertia Composite Golf Club Head,
which pertinent parts are hereby incorporated by reference.
In a preferred embodiment, the golf club head 42 has a high coefficient
of restitution thereby enabling for greater distance of a golf ball hit with
the
golf club 40. The coefficient of restitution (also referred to herein as
"COR")
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
26
is determined by the following equation:
e = vz=r
Ul -U2
wherein U, is the club head velocity prior to impact; U2 is the golf ball
velocity prior to impact which is zero; vi is the club head velocity just
after
separation of the golf ball from the face of the club head; v2 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 the club
face.
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 coefficient of restitution of the club head 42 under standard USGA
test conditions with a given ball ranges from approximately 0.81 to 0.94,
preferably ranges from 0.825 to 0.883 and is most preferably 0.845.
The golf club head 42 of the present invention has a more consistent
COR over the striking plate 72 than prior art golf clubs heads. As shown in
FIG. 2A, the COR is tested at nine locations on the face wall 72' or striking
plate 72. The first location is the geometric face center of the striking
plate,
which is designated GFC. The other locations 801-808, are positioned in
reference to the geometric face center, GFC. The other locations include: a
location 803 which is 0.25 inch heel-ward from the face center; a location 804
which is 0.5 inch heel-ward from the face center; a location 802 which is 0.25
inch toe-ward from the face center; a location 801 which is 0.5 inch toe-ward
from the face center; a location 807 which is 0.25 inch crown-ward from the
face center; a location 808 which is 0.5 inch crown-ward from the face center;
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
27
a location 805 which is 0.25 inch sole-ward from the face center; and a
location 806 which is 0.5 inch sole-ward from the face center. A circle on the
face having a diameter of 1 inch with the geometric face center GFC as its
center could also be used an area of consistent COR.
One of the purposes of a COR distribution test is to determine how
much the COR decreases as out from face center in one quarter inch
increments.
A preferred method and apparatus for testing the COR is similar to the
one set forth by the USGA. The purpose of the test is to replicate the
boundary conditions under which a golf ball strikes a face of a golf club head
and the location where the ball strikes the face of the golf club head. The
basic
elements of the apparatus are: a safety enclosure with a door interlocked to a
firing circuit; a three axis platform to adjust the target to the geometric
(spatial) requirements; a holder(s) to accommodate the specific golf club
head;
a barrel, breech and firing assembly of a cannon; an alignment laser to
indicate
where the ball should strike the face of the golf club head; a dedicated
computer with specialized software to operate the cannon; a sync sensor to
trigger; and a display.
The face of the golf club head should be prepared for mapping. Impact
tape is preferably placed at the center of the face located on an appropriate
score line. After each shot, the X and Y coordinates of the location is
recorded. Preferably, twenty-five valid shots are used fo reach club head. The
shots should begin at the face center and then move side to side and then up
and down. Shots (of a golf ball) should continue to be fired at the face until
the highest velocity ratio is achieved and the X,Y coordinate of that highest
velocity is located on the face. A valid shot is a shot that has an inbound
velocity of 109.05mph 0.65mph and a rebound angle < 5.00 in relation to
the inbound angle. Ten valid shots should be fired at the highest velocity
ratio
point on the face. (A valid shot is a shot that has an inbound velocity of
109.09mph 0.34mph, a rebound angle < 5.00 in relation to the inbound
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
28
angle and the ten shots must be within 2mm of the X,Y coordinate of this
location). The shots with the highest and lowest velocity ratios are discarded
from further calculations. The mean of the remaining eight data points is
calculated, and this value is the golf club head velocity ratio.
In a preferred embodiment, the golf club head 42 has a standard
deviation of the COR of less than 0.226. More preferably, the golf club head
42 has a standard deviation of the COR of less than 0.180. Even more
preferably, the golf club head 42 has a standard deviation of the COR of less
than 0.165. Alternatively, the golf club head 42 has a standard deviation of
the
COR of ranging from 0.225 to 0.150.
The standard deviation is defined as a measure of the dispersion of a
frequency distribution that is the square root of the arithmetic mean of the
squares of the deviation of each of the class frequencies from the arithmetic
mean of the frequency distribution.
Further, the golf club head 42 of the present invention preferably has a
smaller change in value between the COR value of the geometric face center,
GFC, and location 806 which is 0.5 inch sole-ward from the face center.
Preferably, the A of the COR value between the geometric face center, GFC,
and location 806 is less than 0.065. More preferably, A of the COR value
between the geometric face center, GFC, and location 806 is less than 0.058,
and even more preferably less than 0.050. A preferred range for the A of the
COR value between the geometric face center, GFC, and location 806 is 0.068
to 0.040.
Table One illustrates the standard deviation and the A of the COR
value between a geometric face center and a location which is 0.5 inch sole-
ward from the face center of the golf club head of the present invention as
compared to currently commercially available golf club heads.
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
29
TABLE ONE
Golf club head Standard Deviation A of the COR value
Golf Club Head Example 0.160 0.048
CALLAWAY GOLF
BIG BERTHA 0.227 0.059
FUSION
FT-3TM Driver
COBRA SZ440 Driver 0.263 0.079
TAYLOR-MADE 0.275 0.080
R5TM
Driver
Additionally, the striking plate portion 72 of the face component 60 has
a more rectangular face providing a greater aspect ratio. The aspect ratio as
used herein is defined as the width, "W", of the face divided by the height,
"H", of the face. In one preferred embodiment, the width W is 100 millimeters
and the height H is 56 millimeters giving an aspect ratio of 1.8. The striking
plate portion 72 of the present invention preferably has an aspect ratio that
is
greater than 1.8 for a club head having a volume greater than 420 cubic
centimeters.
The face area of the striking plate portion 72 preferably ranges from
5.00 square inches to 10.0 square inches, more preferably from 6.0 square
inches to 9.5 square inches, and most preferably from 7.0 square inches to 9.0
square inches.
FIGS. 23 and 26 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 portion 72 through the center of
gravity, CG, and to the rear of the golf club head 42. The Y-axis extends from
the toe end 68 of the golf club head 42 through the center of gravity, CG, and
to the heel end 66 of the golf club head 42. The Z-axis extends from the
crown portion 62 through the center of gravity, CG, and through the sole
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
portion 64.
As defined in Go f Club Design, Fitting, Alteration & Repair, 4'h
Edition, by Ralph Maltby, the center of gravity, or center of mass, of the
golf
club head is a point inside of the club head determined by the vertical
5 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 42
are preferably measured using a test frame (XT, YT, ZT), and then transformed
10 to a head frame (XH, Y'-', ZH). 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, entitled High Moment Of Inertia
Composite Golf Club, and hereby incorporated by reference in its entirety. If
a
shaft is present, it is removed and replaced with a hosel cube that has a
15 multitude of faces normal to the axes of the golf club head. Given the
weight
of the golf club head, the scales allow one to determine the weight
distribution
of the golf club head when the golf club head is placed on both scales
simultaneously and weighed along a particular direction, the X, Y or Z
direction. Those skilled in the pertinent art will recognize other methods to
20 determine the center of gravity and moments of inertia of a golf club head.
In general, the moment of inertia, Izz, about the Z axis for the golf club
head 42 of the present invention will range from 3500g-cm2 to 6000g-cm2,
preferably from 4000g-cm2 to 5000g-cm2, and most preferably from 4200g-
cm 2 to 4750g-cmZ. The moment of inertia, lyy, about the Y axis for the golf
25 club head 42 of the present invention will range from 2000g-cm2 to 4000g-
cmZ, preferably from 2500g-cm 2 to 3500g-cm2, and most preferably from
2900g-cmz to 3300g-cm2 . The moment of inertia, Ixx, about the X axis for the
golf club head 42 of the present invention will range from 2000g-cm2 to
4000g-cmZ, preferably from 2500g-cm2 to 3750g-cmZ, and most preferably
2 30 from 3000g-cm to 3500g-cmz.
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
31
In general, the golf club head 42 has products of inertia such as
disclosed in U.S. Patent Number 6,425,832, which was filed on July 26, 2001
and is hereby incorporated by reference in its entirety. Preferably, each of
the
products of inertia, Ixy, Ixz and Iyz, of the golf club head 42 have an
absolute
value less than 100 grams-centimeter squared. Alternatively, at least two of
the products of inertia, Ixy, Ixz or Iyz, of the golf club head 42 have an
absolute value less than 100 grams-centimeter squared.
FIGS. 17-21 illustrate the substantial straightness of the heel wall 166,
the toe wall 168 and the rear wall 170 of the club head 42. In a preferred
embodiment, at least 50% of the length of the heel wall 166 extends rearward
from the perimeter 73 of the striking plate portion 72 within an angle of 80
degrees to 90 degrees relative to a plane parallel to the farthest extent of
the
striking plate portion 72. For example, in FIG. 18, line 502 represents a
plane
parallel to the farthest extent of the striking plate portion 72 and line 503
is at
an angle of 90 degrees relative to line 502. Shown in a dashed line is a line
at
80 degrees relative to line 502. In a more preferred embodiment, at least 66%
of the length of the heel wall 166 extends rearward from the perimeter 73 of
the striking plate portion 72 within an angle of 80 degrees to 90 degrees
relative to a plane parallel to the farthest extent of the striking plate
portion 72.
In yet an even more preferred embodiment, at least 75% of the length of the
heel wall 166 extends rearward from the perimeter 73 of the striking plate
portion 72 within an angle of 80 degrees to 90 degrees relative to a plane
parallel to the farthest extent of the striking plate portion 72. In yet a
further
more preferred embodiment, at least 90% of the length or even at least 95% of
the length of the heel wall 166 extends rearward from the perimeter 73 of the
striking plate portion 72 within an angle of 80 degrees to 90 degrees relative
to
a plane parallel to the farthest extent of the striking plate portion 72.
Further,
50% to 95% of the length of the heel wall 166 preferably extends rearward
from the perimeter 73 of the striking plate portion 72 within an angle of 80
degrees to 90 degrees relative to a plane parallel to the farthest extent of
the
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
32
striking plate portion 72, more preferably 66% to 80%.
In a preferred embodiment, at least 50% of the length of the toe wall
168 extends rearward from the perimeter 73 of the striking plate portion 72
within an angle of 80 degrees to 90 degrees relative to a plane parallel to
the
5, farthest extent of the striking plate portion 72. For example, in FIG. 20,
line
504 represents a plane parallel to the farthest extent of the striking plate
portion 72 and line 504 is at an angle of 90 degrees relative to line 504.
Shown in a dashed line is a line at 80 degrees relative to line 502. In a more
preferred embodiment, at least 66% of the length of the toe wall 168 extends
rearward from the perimeter 73 of the striking plate portion 72 within an
angle
of 80 degrees to 90 degrees relative to a plane parallel to the farthest
extent of
the striking plate portion 72. In yet an even more preferred embodiment, at
least 75% of the length of the toe wall 168 extends rearward from the
perimeter 73 of the striking plate portion 72 within an angle of 80 degrees to
90 degrees relative to a plane parallel to the farthest extent of the striking
plate
portion 72. In yet a further more preferred embodiment, at least 90% of the
length or even at least 95% of the length of the toe wall 168 extends rearward
from the perimeter 73 of the striking plate portion 72 within an angle of 80
degrees to 90 degrees relative to a plane parallel to the farthest extent of
the
striking plate portion 72. Further, 50% to 95% of the length of the toe wall
168 preferably extends rearward from the perimeter 73 of the striking plate
portion 72 within an angle of 80 degrees to 90 degrees relative to a plane
parallel to the farthest extent of the striking plate portion 72, more
preferably
66% to 80%.
In a preferred embodiment, at least 50% of the length of the rear wall
170 extends substantially parallel with a farthest extent of the striking
plate
portion 72 within an angle of 80 degrees to 90 degrees relative to a plane
parallel to the farthest extent of the heel wall 166. For example, in FIG. 17,
line 501 represents a plane parallel to the farthest extent of the heel wall
166
and line 500 is at an angle of 90 degrees relative to line 501. Shown in a
CA 02574939 2007-01-23
WO 2006/073930 PCT/US2005/047050
33
dashed line is a line at 80 degrees relative to line 501 and a line at 60
degrees
relative to line 501. In a more preferred embodiment, at least 66% of the
length of the rear wall 170 extends substantially parallel with a farthest
extent
of the striking plate portion 72 within an angle of 80 degrees to 90 degrees
relative to a plane parallel to the farthest extent of the heel wall 166. In
yet an
even more preferred embodiment, at least 75% of the length of the rear wall
170 extends substantially parallel with a farthest extent of the striking
plate
portion 72 within an angle of 80 degrees to 90 degrees relative to a plane
parallel to the farthest extent of the heel wall 166. In yet a further more
preferred embodiment, at least 90% of the length of the heel wall 170 extends
substantially parallel with a farthest extent of the striking plate portion 72
within an angle of 80 degrees to 90 degrees relative to a plane parallel to
the
farthest extent of the heel wall 166. Further, 50% to 95% of the length of the
rear wall 170 preferably extends substantially parallel with a farthest extent
of
the striking plate portion 72 within an angle of 80 degrees to 90 degrees
relative to a plane parallel to the farthest extent of the heel wall 166, more
preferably 66% to 80%.
As shown in FIG. 21, a distance "Dmh" from the center of gravity, CG,
of the club head 42 to an aft-heel edge point 150 ranges from 1.0 inches to
3.5
inches, and more preferably from 2.0 inches to 3.0 inches, and is most
preferably 2.25 inches. A distance "Dmt" from the geometric center to an aft-
toe edge point 155 ranges from 1.75 inches to 4.0 inches, and more preferably
from 2.5 inches to 3.75 inches, and is most preferably 3.25 inches. In a
preferred embodiment, the distance Dmt is the farthest distance of any point
on
the club head 42 from the center of gravity of the club head 42. Further, with
a weighting member 122b positioned at about aft-toe edge point 155, the
weighting member 122b represents the greatest mass in the least volume the
farthest away from the center of gravity of the club head 42.
