U.S. patent application number 14/538614 was filed with the patent office on 2015-03-05 for golf club head.
This patent application is currently assigned to Taylor Made Golf Company, Inc.. The applicant listed for this patent is Taylor Made Golf Company, Inc.. Invention is credited to Marni D. Ines, Bret H. Wahl.
Application Number | 20150065267 14/538614 |
Document ID | / |
Family ID | 49122272 |
Filed Date | 2015-03-05 |
United States Patent
Application |
20150065267 |
Kind Code |
A1 |
Wahl; Bret H. ; et
al. |
March 5, 2015 |
GOLF CLUB HEAD
Abstract
A cavity back iron type club head includes a striking plate
having a substantially planar striking surface and a rear surface
defining a thickness therebetween. The rear surface defines a
striking plate rear cavity region. A perimeter support is coupled
to a peripheral portion of the striking plate. The surface area of
the striking surface is related to the club head loft angle by the
equation SSA.gtoreq.14.4(L)+2875, where SSA is the surface area of
the striking surface in units of square-millimeters and L is the
club head loft angle in units of degrees.
Inventors: |
Wahl; Bret H.; (Escondido,
CA) ; Ines; Marni D.; (San Marcos, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Taylor Made Golf Company, Inc. |
Carlsbad |
CA |
US |
|
|
Assignee: |
Taylor Made Golf Company,
Inc.
Carlsbad
CA
|
Family ID: |
49122272 |
Appl. No.: |
14/538614 |
Filed: |
November 11, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13971786 |
Aug 20, 2013 |
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14538614 |
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11877580 |
Oct 23, 2007 |
8535177 |
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13971786 |
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Current U.S.
Class: |
473/342 |
Current CPC
Class: |
A63B 60/00 20151001;
A63B 53/0416 20200801; A63B 53/0487 20130101; A63B 53/0458
20200801; A63B 60/54 20151001; A63B 53/0408 20200801; A63B 2209/00
20130101; A63B 53/0466 20130101; A63B 2053/0491 20130101; A63B
53/042 20200801; A63B 53/0454 20200801; A63B 69/3635 20130101; A63B
2209/02 20130101; A63B 53/04 20130101; A63B 53/047 20130101; A63B
53/0475 20130101; A63B 2053/0495 20130101; A63B 53/045
20200801 |
Class at
Publication: |
473/342 |
International
Class: |
A63B 53/04 20060101
A63B053/04 |
Claims
1. A cavity back iron type club head having a prescribed loft
angle, the club head comprising: a striking plate having a
substantially planar striking surface, a rear surface, and a
striking plate thickness, the rear surface defining a striking
plate rear cavity region; wherein the striking plate thickness is
defined as a thickness between a selected point on the striking
surface and the rear surface along an axis perpendicular to the
striking surface; an unsupported striking plate area defined as the
portion of the striking plate rear cavity region lacking a backing
support structure having a modulus of elasticity greater than about
25 GPa; an unsupported area ratio defined as a ratio of the
unsupported striking plate area to the surface area of the striking
surface; wherein an average striking plate thickness within the
striking plate rear cavity region is less than about 2.2 mm;
wherein the unsupported striking plate area is greater than about
2572 mm.sup.2, and the loft angle ranges from 22.5 degrees to 34.5
degrees.
2. The cavity back iron type club head of claim 1, wherein the
average striking plate thickness within the striking plate rear
cavity region is less than about 2.1 mm.
3. The cavity back iron type club head of claim 1, wherein the
average striking plate thickness within the striking plate rear
cavity region is less than about 2.0 mm.
4. The cavity back iron type club head of claim 1, wherein the
average striking plate thickness within the striking plate rear
cavity region is less than about 1.9 mm.
5. The cavity back iron type club head of claim 1, wherein the
average striking plate thickness within the striking plate rear
cavity region is less than about 1.8 mm.
6. The cavity back iron type club head of claim 1, wherein the
unsupported striking plate ratio ranges from about 83% to about
88%.
7. The cavity back iron type club head of claim 3, and wherein the
unsupported striking plate ratio ranges from about 83% to about
88%.
8. The cavity back iron type club head of claim 7, wherein the loft
angle ranges from 27.5 degrees to 30.5 degrees.
9. A cavity back iron type club head having a prescribed loft
angle, the club head comprising: a striking plate having a
substantially planar striking surface, a rear surface, and a
striking plate thickness, the rear surface defining a striking
plate rear cavity region; wherein the striking plate thickness is
defined as a thickness between a selected point on the striking
surface and the rear surface along an axis perpendicular to the
striking surface; an unsupported striking plate area defined as the
portion of the striking plate rear cavity region lacking a backing
support structure having a modulus of elasticity greater than about
25 GPa; an unsupported area ratio defined as a ratio of the
unsupported striking plate area to the surface area of the striking
surface; wherein an average striking plate thickness within the
striking plate rear cavity region is less than about 2.2 mm;
wherein the unsupported striking plate ratio is greater than or
equal to 80%, and the loft angle ranges from 22.5 degrees to 34.5
degrees.
10. The cavity back iron type club head of claim 9, wherein the
average striking plate thickness within the striking plate rear
cavity region is less than about 2.1 mm.
11. The cavity back iron type club head of claim 9, wherein the
average striking plate thickness within the striking plate rear
cavity region is less than about 2.0 mm.
12. The cavity back iron type club head of claim 9, wherein the
average striking plate thickness within the striking plate rear
cavity region is less than about 1.9 mm.
13. The cavity back iron type club head of claim 9, wherein the
average striking plate thickness within the striking plate rear
cavity region is less than about 1.8 mm.
14. The cavity back iron type club head of claim 9, wherein the
unsupported striking plate ratio ranges from about 83% to about
88%.
15. The cavity back iron type club head of claim 11, wherein the
unsupported striking plate ratio ranges from about 83% to about
88%.
16. The cavity back iron type club head of claim 15, wherein the
loft angle ranges from 27.5 degrees to 30.5 degrees.
17. An iron type club head comprising: a main body; a striking
plate attached to the main body, the striking plate having a
substantially planar striking surface and a rear surface defining a
striking plate thickness there between, the rear surface defining a
striking plate rear cavity region; an unsupported striking plate
area defined as the portion of the striking plate rear cavity
region lacking a backing support structure; and wherein at least a
portion of the striking plate is a precipitation-hardenable alloy
club head and the striking plate thickness is less than 2.2 mm over
a substantial portion of the unsupported striking plate area, and
wherein the unsupported striking plate area is greater than about
2572 mm.sup.2, and the loft angle ranges from 22.5 degrees to 34.5
degrees.
18. The iron type club head of claim 17, wherein an average
striking plate thickness within the striking plate rear cavity
region is less than about 2.0 mm, the unsupported striking plate
ratio ranges from about 83% to about 88%, and the loft angle ranges
from 27.5 degrees to 30.5 degrees.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/971,786, filed Aug. 20, 2013, which is a
continuation of U.S. patent application Ser. No. 11/877,580, filed
Oct. 23, 2007, now U.S. Pat. No. 8,535,177, which are incorporated
herein by reference in their entirety.
TECHNICAL FIELD
[0002] The disclosure pertains to iron type golf clubs.
BACKGROUND
[0003] The performance of golf equipment is continuously advancing
due to the introduction of advanced materials to both golf clubs
(irons, woods, and putters) and balls, as well as the development
of innovative clubs and club designs such as high loft woods and
oversize drivers. While all clubs in the golfer's bag are
important, both scratch and novice golfers rely on the performance
and feel of their irons for many commonly encountered playing
situations.
[0004] Irons are generally configured in a set that includes clubs
of varying loft, with shaft lengths and clubhead weights selected
to maintain an approximately constant "swing weight" so that the
golfer perceives a common "feel" or "balance" in swinging both the
low irons and high irons in a set. The size of an iron's "sweet
spot" is generally related to the size (i.e., surface area) of the
iron's striking face, and iron sets are available with oversize
club heads to provide a large sweet spot that is desirable to many
golfers.
[0005] Conventional "blade" type irons have been largely displaced
(especially for novice golfers) by so-called "perimeter weighted"
irons, which include "cavity-back" and "hollow" iron designs.
Cavity-back irons have a cavity directly behind the striking plate,
which permits club head mass to be distributed about the perimeter
of the striking plate, and such clubs tend to be more forgiving to
off-center hits. Hollow irons have features similar to cavity-back
irons, but the cavity is enclosed by a rear wall to form a hollow
region behind the striking plate. Perimeter weighted, cavity back,
and hollow iron designs permit club designers to redistribute club
head mass to achieve intended playing characteristics associated
with, for example, placement of club head center of mass or a
moment of inertia.
[0006] While perimeter-weighted designs offer more design
possibilities than blade type designs, perimeter weighting can
result in clubs with an undesirable "feel." In addition, even with
perimeter weighting, significant portions of club head mass, such
as the mass associated with the striking plate, are unavailable for
redistribution. Additional design flexibility is needed for
improved club heads and clubs.
SUMMARY
[0007] A cavity back iron type club head includes a striking plate
having a substantially planar striking surface and a rear surface
defining a thickness therebetween. The rear surface defines a
striking plate rear cavity region. A perimeter support is coupled
to a peripheral portion of the striking plate. The surface area of
the striking surface is related to the club head loft angle by the
equation SSA.gtoreq.14.4(L)+2875, where SSA is the surface area of
the striking surface in units of square-millimeters and L is a club
head loft angle in units of degrees.
[0008] In alternative examples, the cavity back iron type club head
may include an unsupported striking plate area defined as the
portion of the striking plate rear cavity region lacking a backing
support structure having a modulus of elasticity greater than about
25 GPa. An unsupported area ratio defined as a ratio of the
unsupported striking plate area and the surface area of the
striking surface may be used to characterize the club head. In some
examples, the unsupported area ratio is greater than or equal to
80%.
[0009] In yet other alternative examples, the striking plate
thickness and the unsupported striking plate area may be associated
with a characteristic thickness ratio defined as a ratio of the
average striking plate thickness within the striking plate rear
cavity region and a square root of the unsupported striking plate
area. In some examples, the characteristic thickness ratio is less
than about 5%.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is an exploded view of a representative club head for
an iron type golf club.
[0011] FIG. 2 is an elevational view of the representative club
head of FIG. 1.
[0012] FIG. 3 is a partial sectional view of the golf club head of
FIG. 1 illustrating a cartridge insert in contact with a rear
surface of a striking plate.
[0013] FIG. 4 is an additional sectional view of the golf club head
of FIG. 1 illustrating contact of the cartridge insert with a rear
surface of a striking plate.
[0014] FIGS. 5A-5B are views of rear surfaces of representative
striking plates.
[0015] FIG. 5C is a sectional view of the striking plate of FIG. 5A
illustrating a control feature defined on the rear surface of the
striking plate.
[0016] FIG. 6 illustrates an additional example of a cartridge
configured for placement in a head body of an iron type golf
club.
[0017] FIGS. 7A-7B illustrate a variable thickness striking plate
that includes a thinned circular striking zone.
[0018] FIGS. 8A-8C illustrate a club head that includes a variable
thickness striking plate having an oval striking area.
DETAILED DESCRIPTION
[0019] Referring to FIGS. 1-4, an iron-type club head 100 includes
a head body 110, a cartridge assembly 120, and a striking plate
130. The head body 110 includes a heel 112, a toe 113, a top line
114, a sole 116, and a hosel 140 configured to attach the club head
100 to a shaft (not shown in FIGS. 1-4). The head body 110 defines
a front opening 121 configured to receive the striking plate 130 at
a front rim 119 formed around a periphery of the front opening 121.
Club head mass may be distributed about the perimeter of the club
body 110 based on a particular mass distribution for the club head
100 selected by a club head designer. Perimeter weighting can take
various forms. Typical designs include a sole bar or other mass at
or near the club head sole 116 to provide a center of gravity that
is situated low in the club head 100 and behind the striking plate
130 as viewed from a striking surface 132 of the club head.
[0020] As shown in FIG. 1, the striking plate 130 and the head body
110 may be formed separately. In such a design, the completed club
head 100 is made by placing the striking plate 130 in the front
opening 121 and in contact with the front rim 119. The striking
plate 130 is then welded or otherwise secured to the heady body
110, thereby forming a cavity 118 behind a rear surface 134 of the
striking plate 130. When secured to the head body 110, the striking
plate 130 is supported at or by the front rim 119. As defined
herein, the striking surface 132 is a substantially planar surface
configured to strike a golf ball. As shown in FIG. 3, where the
striking plate 130 and the head body 110 are formed separately, the
striking surface 132 may be defined by both the striking plate and
at least a portion of the front rim 119 of the head body if the
substantially planar striking surface extends beyond the periphery
of the striking plate.
[0021] Grinding and/or polishing operations can be used to remove
any excess material or irregularities introduced in the welding
process, or to provide a selected club head appearance such as, for
example, a specularly reflective polished appearance, or other
appearance. The striking plate 130 may also include a set of
scorelines, such as exemplary scorelines 135, 136 formed in the
striking surface 132.
[0022] The head body 110 includes a sole cavity 126 formed in
proximity to a sole portion of the head body 110 and configured to
receive a cartridge assembly 120. The sole cavity 126 is defined in
part by a sole-facing surface 127 and a rear cavity surface 128.
The sole cavity 126 is configured so that at least a portion of a
surface of the cartridge assembly 120 contacts the rear surface 134
of the striking plate 130 when a cartridge assembly 120 is inserted
into the sole cavity 126. Typically, the cartridge assembly 120
contacts at least some portions of the sole-facing surface 127 and
the rear cavity surface 128, and is secured to the sole-facing
surface 127.
[0023] As described above, the striking plate 130 and the head body
110 may be formed separately. However, alternative manufacturing
processes can also be used. For example, the head body 110 and the
striking plate 130 can be formed as one piece using various
forging, casting, and molding processes as are commonly practiced
by golf club head manufacturers. Where the head body 110 and the
striking plate 130 are formed as one piece, the substantially
planar striking surface 132 is defined by the one piece club
head.
[0024] In one embodiment, the cartridge assembly 120 includes a
cartridge body 122 that is configured to receive one or more
cartridge inserts 124. Typically the cartridge body 122 is provided
with one or more cylindrical bores or other cavities that retain
the cartridge inserts 124. Generally the cartridge body 122 has a
modulus of elasticity that is lower than that of the cartridge
inserts 124.
[0025] Some examples of materials that can be used to form the
cartridge body 122 include, without limitation, viscoelastic
elastomers; vinyl copolymers with or without inorganic fillers;
polyvinyl acetate with or without mineral fillers such as barium
sulfate; acrylics; polyesters; polyurethanes; polyethers;
polyamides; polybutadienes; polystyrenes; polyisoprenes;
polyethylenes; polyolefins; styrene/isoprene block copolymers;
metallized polyesters; metallized acrylics; epoxies; epoxy and
graphite composites; natural and synthetic rubbers; piezoelectric
ceramics; thermoset and thermoplastic rubbers; foamed polymers;
ionomers; low-density fiber glass; bitumen; silicone; and mixtures
thereof. The metallized polyesters and acrylics can comprise
aluminum as the metal. Commercially available materials include
resilient polymeric materials such as Scotchdamp.TM. from 3M,
Sorbothane.RTM. from Sorbothane, Inc., DYAD.RTM. and GP.RTM. from
Soundcoat Company Inc., Dynamat.RTM. from Dynamat Control of North
America, Inc., NoViFlex.TM. Sylomer.RTM. from Pole Star Maritime
Group, LLC, Isoplast.RTM. from The Dow Chemical Company, and
Legetolex.TM. from Piqua Technologies, Inc. In one embodiment the
cartridge body 122 may be formed from a material having a modulus
of elasticity ranging from about 0.001 GPa to about 25 GPa, and a
durometer ranging from about 10 to about 30 on a Shore D scale. In
a preferred embodiment the cartridge body 122 may be formed from a
material having a modulus of elasticity ranging from about 0.001
GPa to about 10 GPa, and a durometer ranging from about 15 to about
25 on a Shore D scale. In a most preferred embodiment the cartridge
body 122 may be formed from a material having a modulus of
elasticity ranging from about 0.001 GPa to about 5 GPa, and a
durometer ranging from about 18 to about 22 on a Shore D scale. In
some examples, a material providing vibration damping is
preferred.
[0026] As shown in FIGS. 1-4, the cartridge inserts 124 are
typically formed of relatively dense materials that permit a center
of gravity of a club head to be low and rearward of the striking
surface 132. Some examples of materials that can be used to form
the cartridge inserts 124 include, without limitation, steel
alloys, tungsten and tungsten alloys, other metals and metal
alloys, or other materials. Typical densities of such materials are
preferably greater than about 2.5 g/cm.sup.3 or 5.0 g/cm.sup.3. In
some preferred examples, insert densities are at least about 15
g/cm.sup.3.
[0027] In order to provide selected mass, mass distribution, and/or
vibration dampening characteristics, in some examples the cartridge
body 122 can be provided with an additional loading material as
spheres, rods, fibers or other particles that are distributed
throughout the cartridge body 122. In other examples, the cartridge
body 122 may comprise two or more sections of different materials
that are configured to provide such benefits. In yet other
examples, the cartridge assembly 120 may be formed without
cartridge inserts 124, and fiber or particulate loading material
may be distributed throughout the cartridge body 122 to achieve
desirable mass distribution and/or vibration dampening
characteristics. The fiber or particulate loading material may be
formed from materials such as those listed above with respect to
the cartridge inserts 124. Other cartridge body 122 configurations
may include a laminar structure comprising alternating layers of
materials having varying modulus of elasticity values.
[0028] The cartridge assembly 120 can be conveniently secured to
the sole cavity 126 in the club head 100 with a tape strip 129,
other adhesive, or otherwise secured or retained in the sole cavity
126. Cartridge inserts 124 can be cylindrical or other shapes, or
can be omitted based on the dimensions and density of the cartridge
body 122. A badge 125 can be applied to the head body 110, to
control mass distribution, for ornamentation, club identification,
or other purposes. As shown in FIGS. 3-4, the cartridge body 122,
as retained by the head body 110, is configured to contact the rear
surface 134 of the striking plate 130 in a cartridge contact
area.
[0029] Referring to FIG. 3, the rear surface 134 of the striking
plate 130 is opposite the striking surface 132 and faces the cavity
118. For an iron manufactured using pull face construction, a
perimeter portion 138 of striking plate 130 contacts the head body
110 at the front rim 119. A striking plate rear cavity region is
defined as the portion of the striking plate rear surface 134 that
is exposed to the cavity 118. Consequently, for an iron
manufactured using pull face construction, the portions of the
striking plate rear surface 134 supported by the front rim 119 are
not included within the striking plate rear cavity region.
[0030] The surface area of the striking surface 132 (i.e., the
surface area of the substantially planar surface defined by the
striking plate 130 and the perimeter portion 138) can be selected
based on, for example, club type, striking surface shape, and
whether or not the club is to be a so-called "oversized" club. The
thickness of the striking plate 130 is defined as the distance
between a selected point on the striking face 132 and the rear
surface 134 along an axis perpendicular to the striking face 132.
The striking plate thickness can be selected to reduce mass
associated with the striking plate 130, so that additional mass can
be distributed to other parts of the club head 100 to achieve
intended club design goals. Typically, striking plate thickness is
selected consistent with long term club use to avoid premature
striking plate failure due to fatigue cracking and other such
failure modes. Typically, redistributed mass is situated low on the
club head 100 and rearward of the striking plate 130.
[0031] Some examples of materials that can be used to form the
striking plate and the head body include, without limitation,
carbon steels (e.g., 1020 or 8620 carbon steel), stainless steels
(e.g., 304, 410, or 431 stainless steel), PH
(precipitation-hardenable) alloys (e.g., 17-4, C450, or C455
alloys), titanium alloys (e.g., 3-2.5, 6-4, SP700, 15-3-3-3,
10-2-3, or other alpha/near alpha, alpha-beta, and beta/near beta
titanium alloys), aluminum/aluminum alloys (e.g., 3000 series
alloys, 5000 series alloys, 6000 series alloys, such as 6061-T6,
and 7000 series alloys, such as 7075), magnesium alloys, copper
alloys, nickel alloys, glass fiber reinforced polymers (GFRP),
carbon fiber reinforced polymers (CFRP), metal matrix composites
(MMC), ceramic matrix composites (CMC), and natural composites
(e.g., wood composites). High strength materials having a
relatively high modulus of elasticity (typically greater than about
50 GPa, 100 GPa, 150 GPa, 200 GPa, or 250 GPa) are generally
preferred. In use, the striking plate 130 is subject to numerous
high speed impacts with a golf ball, and should resist cracking and
permanent deformation. Different types of irons (e.g., long irons
and short irons) can experience different forces in golf ball
impacts, and striking plate thickness can be adjusted accordingly,
if desired.
[0032] FIGS. 5A-5B illustrate control features 152, 154 situated on
rear surfaces (i.e., surfaces opposite a striking surface) of
representative striking plates 150, 151. Referring to FIG. 5C, the
control feature 154 is defined by a recess 155 in the rear surface
that is provided with a plurality of grooves such as a
representative groove 158. Control features can be adjusted to
provide a selected club playing characteristic, typically to
provide an intended sound when striking a golf ball. FIGS. 5A-5B
also illustrate representative striking plate areas in which a
cartridge assembly such as the cartridge assembly 120 or other
cartridges or cartridge assemblies contacts a rear surface of a
striking plate. For example, as shown in FIG. 5A, the striking
plate 150 contacts a cartridge assembly in a cartridge contact area
157 situated on the rear surface of the striking plate 150. In
another representative example shown in FIG. 5B, the striking plate
151 contacts a cartridge assembly in surface area portions 159A,
159B, 159C.
[0033] Striking plate dimensions can vary based on striking plate
composition and preferred club head dimensions. Larger or smaller
striking surfaces can be provided for "short" or "long" irons, if
desired. Typically, cavity-back club head designs such as the
example of FIGS. 1-4 include a thin striking plate so that striking
plate mass is reduced and redistributed to the club head perimeter.
All or a portion of the rear surface 134 of the striking plate 130
within the striking plate rear cavity region may be unsupported by
the clubhead body such that the striking plate deforms upon impact
with a golf ball.
[0034] In some embodiments, a cartridge or cartridge assembly may
be configured to contact a portion of the rear surface 134 of the
striking plate 130 in a secondary support area, or cartridge
contact area. In this way, the cartridge allows for a thinner
striking plate because of the additional support the cartridge
provides to the striking plate. As used herein, portions of a
striking plate or other striking member of a golf club that lack a
backing support structure (e.g., a cartridge or cartridge assembly)
having a modulus of elasticity greater than about 25 GPa are
referred to as unsupported. Consequently, an unsupported striking
plate area may be defined as the portion of the striking plate rear
cavity region lacking a backing support structure having a modulus
of elasticity greater than about 25 GPa, or equivalently the
surface area of the striking plate rear cavity region minus the
cartridge contact area. Striking plate dimensions, surface area of
the striking plate rear cavity region, unsupported striking plate
surface area, striking plate thickness, and cartridge contact area
can be selected based on a desired mass distribution, club
durability, striking plate materials, and other design goals.
[0035] As used herein, a contact area of an elastomeric portion of
a cartridge with a rear surface of a striking plate is referred to
as a secondary support area, or cartridge contact area. As noted
above, the cartridge body may be formed from an elastomeric
material having a modulus of elasticity ranging from about 0.001 to
about 25 GPa. Providing such a secondary support area with
elastomeric materials permits mass reduction in the striking plate
with no decrease in striking plate durability. In order to maintain
a large striking surface, such mass reduction can be conveniently
associated with a relatively thin striking plate. In a typical
example, a stainless steel striking plate (modulus of about 200
GPa) having an unsupported striking plate area of about 2000
mm.sup.2 has an average thickness of about 1.9 mm and a cartridge
contact area of about 400 mm.sup.2. Details for several
representative examples are set forth in the table below.
[0036] While FIGS. 1-4 illustrate a representative cavity back iron
of pull face construction, in other examples cavity back irons are
configured based on one piece (i.e., unitary) construction using
manufacturing methodologies such as forging or casting. In one
piece construction, a striking plate portion can be formed
integrally with a club body, and defines a front striking surface
and a rear surface opposite the front striking surface of the
striking plate portion. In one piece construction, a striking plate
thickness is defined as the distance between a selected point on
the striking surface 132 and the rear surface 134 along an axis
perpendicular to the striking surface 132. Generally in the case of
a cavity back iron of unitary construction, the rear surface 134 of
the striking plate 130 may gradually or abruptly transition from a
relatively thin striking face thickness to a much thicker perimeter
weighting region. In this case the striking plate rear cavity
region is delineated by and includes a peripheral region having a
striking plate thickness less than or equal to about 2.2 mm, which
is bounded by a thicker perimeter weighting region having a
thickness greater than about 2.2 mm. Typically, the maximum
thickness of the perimeter weighting region is at least as thick as
about 4.5 or 6 times the thickness of the thinnest portion of the
striking plate rear cavity region.
[0037] An additional cartridge example is illustrated in FIG. 6.
Referring to FIG. 6, a cartridge 162 includes alternating
elastomeric sections 164 and insert sections 166. The elastomeric
sections are selected from materials having a relatively low
modulus of elasticity, typically less than about 25 GPa, less than
about 10 GPa, less than about 5 GPa, or less than about 1 GPa. The
insert sections 166 are generally formed of stiffer, denser
materials than the elastomeric sections. The modulus of elasticity
for such sections is typically greater than about 10 GPa, 50 GPa,
or 100 GPa. The cartridge 162 includes a contact surface configured
to contact a striking plate rear surface 134, where the contact
surface is defined by surfaces 170-174 of the insert sections.
While the cartridge of FIG. 6 illustrates sections alternating
horizontally, in other examples, the sections can alternate
vertically and fewer or more sections can be provided. In addition,
the insert and elastomeric section alternation can be periodic in
some examples, but generally need not be. In other examples, the
elastomeric sections can be denser and/or stiffer than the insert
sections, and the insert sections configured to contact a striking
plate rear surface. Sections can have rectangular, square, or other
cross sections.
[0038] Striking plates of pull face construction irons or striking
plate portions of one piece cast or forged irons can be
conveniently described based on a characteristic thickness ratio
that is defined as a ratio of the average striking plate thickness
within the striking plate rear cavity region and a square root of
the unsupported striking plate area (i.e., the portion of the
striking plate rear cavity region lacking a backing support
structure having a modulus of elasticity greater than about 25
GPa). In addition, a portion of an unsupported striking plate area
in contact with the cartridge can be described by a relative
cartridge contact area ratio defined as a ratio of the cartridge
contact area and unsupported striking plate area.
[0039] In typical examples, unsupported striking plate areas range
from about 1500 mm.sup.2 to about 3000 mm.sup.2, average striking
plate thickness within the striking plate rear cavity region range
from about 1.5 mm to about 2.2 mm, and cartridge contact areas
range from about 300 mm.sup.2 to about 400 mm.sup.2. Consequently,
characteristic thickness ratios may range from about 2% to about
4.8% and relative cartridge contact area ratios may range from
about 10% to about 25%, or preferably from about 10% to about 18%.
Such club head parameters can vary depending on club head geometry
as affected by material properties such as, for example, a modulus
of elasticity of striking plate material. Parameters can also be
selected based on whether a particular club head is to be a short
iron, a mid iron, or a long iron.
[0040] Club head geometries for three representative club set
configurations A, B, and C are described in Table 1 below. For each
of the three sets, representative values for a 3 iron, a 6 iron,
and a 9 iron are listed. Tabulated values are unsupported striking
plate area (USPA), average striking plate thickness (ASPT),
cartridge contact area (CCA), thickness ratio (CTR), and relative
cartridge contact area ratio (RCAR). The representative club set
heads may be manufactured from discrete components using, for
example, pull face construction methods, or the representative club
set heads may be manufactured as unitary components using, for
example, various casting or forging techniques.
TABLE-US-00001 TABLE 1 Representative club head geometries. Set and
USPA ASPT CCA CTR RCAR Club (mm.sup.2) (mm) (mm.sup.2) (%) (%) A-3
2062 1.8 304 4.0 14.7 A-6 2062 1.8 304 4.0 14.7 A-9 1898 1.8 304
4.1 16.0 B-3 1701 1.9 387 4.6 22.8 B-6 1714 1.9 387 4.6 22.6 B-9
1898 1.9 387 4.4 20.4 C-3 2112 2.1 393 4.6 18.6 C-6 2310 2.1 393
4.4 17.0 C-9 2211 2.1 393 4.5 17.8
[0041] The tabulated values are representative, and other
configurations can be provided as described above. Cartridges can
be configured to provide secondary support areas of various shapes
and sizes, and situated at club locations based on, for example, an
intended mass distribution. Unsupported striking plate surfaces may
be of constant thickness, continuously variable thickness, stepped
thickness, or combinations thereof. In some examples, only portions
of an elastomeric surface of a cartridge contacts the rear surface
of a striking plate or other striking portion.
[0042] Striking plates of pull face construction cavity back irons
or striking plate portions of one piece cast or forged cavity back
irons may also be described based on an unsupported area ratio that
is defined as a ratio of the unsupported striking plate area and
the area of the substantially planar striking surface 132. Club
head geometries for two representative club set configurations D
and E are described in Table 2 below. For club set configuration D,
representative values for 4, 5, 6, 7, 8, and 9 irons are listed.
For club set configuration E, representative values for 5, 6, 7, 8,
and 9 irons are listed. Tabulated values are loft angle (L),
striking surface area (SSA), unsupported striking plate area
(USPA), and unsupported area ratio (UAR). As above, the
representative iron heads may be manufactured from discrete
components using, for example, pull face construction methods, or
the representative club set heads may be manufactured as unitary
components using, for example, various casting or forging
techniques.
TABLE-US-00002 TABLE 2 Representative club head geometries. L SSA
USPA UAR Set and Club (degrees) (mm.sup.2) (mm.sup.2) (%) D-4 20
3167 2599 82.1 D-5 23 3207 2613 81.5 D-6 26 3264 2671 81.8 D-7 30
3314 2697 81.4 D-8 34 3366 2730 81.1 D-9 39 3442 2805 81.3 E-5 22
3214 2572 80.0 E-6 25 3265 2628 80.4 E-7 28 3318 2653 80.0 E-8 32
3366 2743 81.5 E-9 37 3447 2796 81.5
[0043] For each of the exemplary club heads listed in Table 2, the
striking surface area SSA is related to the loft angle L by the
following equation:
SSA.gtoreq.14.4(L)+2875,
wherein SSA is the striking surface area measured in
square-millimeters and L is the loft angle measured in degrees. In
other examples, areas and angles can be expressed in different
units with corresponding changes in any numerical constants in the
equation. This relationship provides for increased striking face
surface area for a given loft angle compared to traditional cavity
back iron club heads. Additionally, the unsupported area ratio for
each of the club heads listed in Table 2 is greater than or equal
to 80%. In alternative embodiments of the invention, the
unsupported area ratio may range from about 80% to about 88%, and
in preferred embodiments of the invention, the unsupported area
ratio may range from about 83% to about 88%.
[0044] The loft angle of an exemplary cavity back 4-iron may range
from about 19 degrees to about 21 degrees, preferably from about
19.5 degrees to about 20.5 degrees; the striking surface area may
range from about 3156 mm.sup.2 to about 3487 mm.sup.2, preferably
from about 3322 mm.sup.2 to about 3487 mm.sup.2; and the
unsupported striking plate ratio is greater than or equal to 80%,
preferably about 83% to about 88%; The loft angle of an exemplary
cavity back 5-iron may range from about 21.5 degrees to about 22.5
degrees, preferably from about 22 degrees to about 23 degrees; the
striking surface area may range from about 3185 mm.sup.2 to about
3519 mm.sup.2, preferably from about 3352 mm.sup.2 to about 3519
mm.sup.2; and the unsupported striking plate ratio is greater than
or equal to 80%, preferably about 83% to about 88%. The loft angle
of an exemplary cavity back 6-iron may range from about 24.5
degrees to about 26.5 degrees, preferably from about 25 degrees to
about 26 degrees; the striking surface area may range from about
3228 mm.sup.2 to about 3582 mm.sup.2, preferably from about 3405
mm.sup.2 to about 3582 mm.sup.2; and the unsupported striking plate
ratio is greater than or equal to 80%, preferably about 83% to
about 88%. The loft angle of an exemplary cavity back 7-iron may
range from about 27.5 degrees to about 30.5 degrees, preferably
from about 28 degrees to about 30 degrees; the striking surface
area may range from about 3271 mm.sup.2 to about 3646 mm.sup.2,
preferably from about 3458 mm.sup.2 to about 3646 mm.sup.2; and the
unsupported striking plate ratio is greater than or equal to 80%,
preferably about 83% to about 88%. The loft angle of an exemplary
cavity back 8-iron may range from about 31.5 degrees to about 34.5
degrees, preferably from about 32 degrees to about 34 degrees; the
striking surface area may range from about 3329 mm.sup.2 to about
3709 mm.sup.2, preferably from about 3519 mm.sup.2 to about 3709
mm.sup.2; and the unsupported striking plate ratio is greater than
or equal to 80%, preferably about 83% to about 88%. The loft angle
of an exemplary cavity back 9-iron may range from about 36.5
degrees to about 39.5 degrees, preferably from about 36 degrees to
about 39 degrees; the striking surface area may range from about
3401 mm.sup.2 to about 3788 mm.sup.2, preferably from about 3594
mm.sup.2 to about 3788 mm.sup.2; and the unsupported striking plate
ratio is greater than or equal to 80%, preferably about 83% to
about 88%.
[0045] Striking plates can be thinned substantially uniformly or
selected locations on a striking plate can be thinned or otherwise
shaped so as to provide a redistribution of mass, a desired "feel"
when used, and/or a preferred "sweet spot" size or location.
Referring to FIGS. 7A-7B, a striking plate 702 includes a thinned
striking region 704 and a relief region 706 that is defined by a
perimeter groove 708. The relief region 706 includes a plurality of
circumferential grooves 711-718 that are typically defined along
circular arcs that are approximately centered about a center 720 of
the striking region 704. As shown in FIGS. 7A-7B, the striking
plate also includes a face region 724 that has a substantially
constant thickness. In some examples, grooves can be defined by
elliptical, parabolic, hyperbolic or other curved arcs, or by
straight line segments, or combinations thereof and situated about
a geometric center of a striking region, a focus of a conic
section, or otherwise situated. In the example of FIG. 7A, at least
some of the grooves 711-718 include a first segment and a second
segment that are disconnected. For example, the grooves 712-714 are
discontinuous and include first and second segments that are
separated by a portion of the face region 724. In the example of
FIG. 7A, the thinned striking region 704 is circular and has a
diameter of about 11.7 mm. A central edge 726 of the relief region
706 extends along a portion of a circular arc having a radius of
10.4 mm centered about the striking region 704.
[0046] As shown in FIG. 7B, the striking plate 702 has a thickness
T=2.2 mm and is relieved by a thickness t=0.5 mm at a thinnest
portion corresponding to the center 720 of the striking region 704
to have a central thickness of about 1.7 mm. A surface 730 of the
region 704 can be defined as, for example, a portion of a spherical
surface. In one example, a radius of a spherical surface associated
with a 0.5 mm decrease in thickness at the center 720 of a 11.7 mm
diameter striking region 704 is about 34.5 mm. A striking surface
740 is provided with a plurality of scorelines 741-748. The relief
region 706 also includes transition segments 760, 762 that couple
the relief region 706 and the support region 724. In the example of
FIG. 7B, surfaces of the transition regions 760, 762 are situated
at about 45 degrees with respect to a surface 764 of the support
region 724. As shown in the example of FIGS. 7A-7B, a thickness of
the striking plate 702 in the relief region 706 is about 1.6 mm,
and the grooves 708, 711-718 extend a distance of about 0.15 mm
into the striking plate 702 and have radii of curvature of about
0.5 mm. More or fewer grooves can be provided in the relief zone,
and relief zones that have larger areas or depths can be used.
[0047] Horizontal (H) and vertical (V) locations of the center of a
striking zone for a representative iron set are included in Table
3. For convenience, approximate striking plate mass is provided for
each club.
TABLE-US-00003 TABLE 3 Representative Striking Plate Specifications
Club Mass (g) H (mm) V(mm) 3 iron 30.7 37.2 19.6 4 iron 31.2 37.2
19.9 5 iron 31.7 37.2 20.4 6 iron 33.1 37.2 21.6 7 iron 33.3 37.4
22.0 8 iron 34.0 37.4 22.1 9 iron 34.6 37.4 24.3 P wedge 35.3 37.3
26.0 A wedge 35.5 37.3 28.2 S wedge 36.4 37.0 28.6
[0048] An additional exemplary striking plate 802 retained in a
head body 804 is illustrated in FIGS. 8A-8C. The striking plate 802
has a thickness T.sub.FACE and includes an oval support area 806
having a central oval area 810 of thickness T.sub.STRIKE and a rim
812 of thickness T.sub.RIM that are provided on a rear surface 814.
The rim 812 defines an oval rim region having interior and exterior
lengths L.sub.I, L.sub.O, respectively and interior and exterior
widths W.sub.I, W.sub.O, respectively. The rim 812 has an annular
width of between about 0.9 mm and 1.5 mm at the thickest portion,
and dimensions of the rim region are based on locations at which
the striking plate thickness is substantially the same as the
thicknesses associated with the striking region and the face
region. A front surface (a striking surface) 816 of the striking
plate 802 includes a plurality of grooves 818. In some examples,
the oval support area 806 is elliptical and lengths and widths
correspond to major and minor axes of ellipses. A bottom edge 817
of a sole 816 typically extends parallel to the ground (and rests
on the ground) when the club is positioned so as to address a ball.
Typically a long axis of the oval support area 806 extend
approximately parallel to the bottom edge 817. In the example of
FIGS. 8A-8C, a striking face area is somewhat thicker than the
remainder of the striking plate. Dimensions of representative
striking plates and associated oval support areas such as
illustrated in FIGS. 8A-8C are listed in Table 4.
TABLE-US-00004 TABLE 4 Representative Striking Plate Dimensions
Example 1 Example 2 Example 3 Example 4 Example 5 T.sub.FACE (mm)
1.9-2.2 1.9-2.2 1.9-2.2 1.9-2.2 1.9-2.2 T.sub.STRIKE (mm) 2.7-2.9
2.4-2.6 2.2-2.9 2.4-2.7 2.5-2.6 T.sub.RIM (mm) 3.4-3.8 2.9-3.2
2.9-3.6 3.1-3.4 3.2-3.3 Striking Face 2825-3113 2793-3152 2800-3200
2800-3200 2800-3200 Area (mm.sup.2) Oval Area 502-554 370-408
390-580 450-550 500-550 (mm.sup.2) L.sub.O (mm) 39.9-44.1 34.2-37.8
32-46 36-44 38-42 W.sub.O (mm) 15.2-16.8 13.1-14.5 11-19 13-17
15.5-16.5 L.sub.I (mm) 20.9-23.1 17.1-18.9 15-25 18-22 19-21
W.sub.I (mm) 7.6-8.4 6.5-7.2 6-9 7-8.5 7.75-8.25
[0049] The striking plate examples shown in FIGS. 7A-7B and 8A-8C
may be provided on a club head using pull face construction or
unitary construction techniques. A variety of other striking plates
can be similarly arranged to include thinned or thickened striking
regions, relief regions, or other features described above.
[0050] The representative clubs, components thereof, and related
assembly and manufacturing methods presented above are examples
only and are not to be taken as limiting. As disclosed above,
striking plates used in pull face club construction or other club
faces can be thinned or thickened to permit improved mass
redistribution. In some examples, portion of a thinned striking
plate are supported or contacted by a weight cartridge, while other
examples, a central or interior portion of a striking plate is
thinner or thicker than a surrounding portion. Thickness changes
can be abrupt or gradual, and tapered thinned or thickened face
plates can be used. Portions of the striking plate can be grooved
or otherwise relieved so that the associated mass can be situated
as desired to provide an intended playing characteristic. These
examples are presented for convenient explanation, and are not to
be taken as limiting the scope of the appended claims. We claim all
that is encompassed by the appended claims.
* * * * *