U.S. patent application number 15/491645 was filed with the patent office on 2017-10-26 for method and apparatus for enhancing surface strike performance.
The applicant listed for this patent is ADAM C. SCLAFANI. Invention is credited to ADAM C. SCLAFANI.
Application Number | 20170304687 15/491645 |
Document ID | / |
Family ID | 60088825 |
Filed Date | 2017-10-26 |
United States Patent
Application |
20170304687 |
Kind Code |
A1 |
SCLAFANI; ADAM C. |
October 26, 2017 |
METHOD AND APPARATUS FOR ENHANCING SURFACE STRIKE PERFORMANCE
Abstract
An apparatus is disclosed having a face which includes a
striking surface. The striking surface has a combination of
properties configured to enhance performance characteristics, such
as a launch angle, carry distance, and spin rate of an associated
ball. The combination of properties of the striking surface at
least includes an adequate hardness, smoothness, and durability. A
method of enhancing surface strike performance is also disclosed.
The method includes providing an associated item of sports
equipment with a face including a ball striking surface having a
combination of properties such as an adequate hardness, smoothness,
and durability.
Inventors: |
SCLAFANI; ADAM C.;
(Uniontown, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCLAFANI; ADAM C. |
Uniontown |
OH |
US |
|
|
Family ID: |
60088825 |
Appl. No.: |
15/491645 |
Filed: |
April 19, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62325124 |
Apr 20, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A63B 53/0466 20130101;
A63B 53/0416 20200801; A63B 53/04 20130101; A63B 2209/00 20130101;
A63B 53/047 20130101 |
International
Class: |
A63B 53/04 20060101
A63B053/04; A63B 53/04 20060101 A63B053/04 |
Claims
1. An apparatus for enhancing surface strike performance,
comprising: a face including a striking surface, wherein the
striking surface has a combination of properties configured to
improve performance characteristics of an associated ball; wherein
the combination of properties of the striking surface includes a
hardness of at least Shore D 65, a surface roughness of Ra 1 .mu.m
or less, and a resistance to indentation at 1,500 psi or greater
for a duration of about 30 minutes measured according to
Mil-D-3134F.
2. The apparatus of claim 1, wherein the performance
characteristics include at least one of an increased launch angle,
an increased carry distance, and a decreased spin rate of the
associated ball.
3. The apparatus of claim 1, wherein the combination of properties
of the striking surface further includes a wear resistance minimum
of zero weight loss at a load of 1 kg per 1000 cycles measured
according to ASTM-C-501.
4. The apparatus of claim 1, wherein the combination of properties
of the striking surface further includes a flexural strength of
greater than about 3,000 psi measured according to ASTM C-580.
5. The apparatus of claim 1, wherein the combination of properties
of the striking surface further includes a tensile strength of
greater than about 3,000 psi measured according to ASTM C-307.
6. The apparatus of claim 1, wherein the combination of properties
of the striking surface further includes a compressive strength of
greater than about 5,000 psi measured according to ASTM C-579.
7. The apparatus of claim 1, wherein the striking surface comprises
a coating applied to at least a portion of the face.
8. The apparatus of claim 7, wherein the coating is a
polyurethane.
9. The apparatus of claim 8, wherein the coating has a thickness of
about 100 .mu.m to about 200 .mu.m.
10. The apparatus of claim 1, wherein the striking surface and the
face are integral.
11. The apparatus of claim 1, wherein the striking surface is
configured to have one or more ridges and/or grooves.
12. The apparatus of claim 1, wherein the striking surface is
configured to be substantially smooth.
13. The apparatus of claim 1, wherein the striking surface
comprises an insert attached to the face.
14. The apparatus of claim 13, wherein the insert further comprises
a substrate and a coating applied to at least a portion of the
substrate.
15. The apparatus of claim 14, wherein the coating is a
polyurethane.
16. The apparatus of claim 13, wherein the striking surface is
configured to have one or more ridges and/or grooves.
17. The apparatus of claim 13, wherein the striking surface is
configured to be substantially smooth.
18. A method of enhancing surface strike performance, comprising:
providing a face of an associated item of sports equipment with a
striking surface having a combination of properties configured to
improve performance characteristics of an associated ball; wherein
the combination of properties of the striking surface includes a
hardness of at least Shore D 65, a surface roughness of Ra 1 .mu.m
or less, and a resistance to indentation at 1,500 psi or greater
for a duration of about 30 minutes measured according to
Mil-D-3134F; and wherein the performance characteristics include at
least one of an increased launch angle, an increased carry
distance, and a decreased spin rate.
19. The method of claim 18, further comprising applying a coating
of polyurethane to the face to form the striking surface having the
combination of properties.
20. An apparatus for enhancing surface strike performance,
comprising: a face including a striking surface, wherein the
striking surface is formed from a coating applied to at least a
portion of the face, and the coating has a combination of
properties configured to improve performance characteristics of an
associated ball, the combination of properties including a hardness
of at least Shore D 65, a surface roughness of Ra 1 .mu.m or less,
and a resistance to indentation at 1,500 psi or greater for a
duration of about 30 minutes measured according to Mil-D-3134F;
wherein the coating is an oil modified polyurethane having a
thickness of about 100 .mu.m to about 200 .mu.m; and wherein the
performance characteristics include at least one of an increased
launch angle, an increased carry distance, and a decreased spin
rate.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent
Application Ser. No. 62/325,124, filed Apr. 20, 2016, the entirety
of which is fully incorporated herein by reference.
BACKGROUND OF THE DISCLOSURE
[0002] The present disclosure relates to golf clubs and related
sports applications. More particularly, it relates to enhanced
surface strike performance of a golf club head, which may be
achieved by a coating applied to the golf club head. Although a
preferred embodiment of the present disclosure is directed to a
golf club head, it is contemplated that other types of sports
equipment (e.g., baseball bats, hockey sticks, polo mallets,
croquet mallets bocce balls, bowling balls, billiard balls, etc.,
and the like) may similarly benefit from the enhanced surface
strike performance disclosed herein.
[0003] The design of typical golf clubs includes specific features
that affect the flight characteristics of the golf ball after
impact. For example, the loft angle of the club, face grooves and
surface characteristics of the club impart a combination of angular
spin and forward velocity at impact. The forward velocity is
further directed along a vector (launch angle) by virtue of the
balls interaction with the clubface at impact.
[0004] The introduction of spin can be a benefit for the highly
skilled golfer and allow the golfer to "work the ball" by
deliberately curving the flight path in a left-to-right or
right-to-left direction. High spin rates may also facilitate the
skilled golfer in reducing the amount of travel on the ground-of
short shots to the green (i.e., getting the ball to "check
up").
[0005] The vast majority of golfers are insufficiently skilled in
the control of spin on the ball. Therefore, the inadvertent and
errant introduction of spin commonly results in either hooking or
slicing the balls flight path in an unintended direction.
[0006] At impact the club head transfers its kinetic energy to the
ball. Conventional golf clubs impart some energy to spin the ball
and the remaining energy to propel the ball. Depending upon the
angle of impact of the club face the proportion of energy diverted
to either spin or propulsion will vary.
[0007] It is preferable to configure a golf club head to achieve
less spin, greater launch angle and increased carry distance.
Historically, one known way modify these golf ball characteristics
is to use a "slippery" clubface. For example, Vaseline.RTM.,
Chopstick.RTM., or other temporary substances applied to the
striking face of the golf club is widely known. These practices,
however, are not "legally conforming" to the Rules of Golf issued
by the United States Golf Association ("USGA"), as these substances
are "temporary modifications." The removal of grooves on the golf
clubface is also widely known in the industry to modify the
aforementioned characteristics of golf balls, and clubs having
groove-less and highly polished clubfaces are currently marketed
today.
[0008] Several patents disclose a number of attempts to achieve
these results. For example, U.S. Pat. No. 6,974,392 ("Chang")
describes a golf club for minimizing spin of the golf ball. The
method described employs the use of low friction substances that
cover the impact surface of the golf club, such as PTFE and
variants of PTFE (Teflon). These substances are known for their low
coefficient of friction, and are thus an obvious attribute for
coating that is expected to reduce the spin of a struck golf
ball.
[0009] Chang further describes how to overcome the limitations of
the method that was previously discussed in U.S. Pat. No. 5,423,535
("Shaw"). Shaw also listed PTFE as a candidate for spin reduction
treatment of golf club face. While being somewhat effective, this
approach of using PTFE had limited functionality and practicality.
As a result, the PTFE coatings on the golf club did not reach the
level of performance expectation. Chang describes the problem as
ultimately relating to the softness of the PTFE and that at impact
the compression of the golf ball into the layer of PTFE produces a
mechanical engagement of the ball against the surface and
introduces unexpected and unwanted spin of the golf ball. The
solution proposed in Chang is to limit the thickness of the PTFE
coating and employ a supporting layer under the PTFE. However, this
limits the degree of mechanical engagement of the PTFE layer with
the golf ball.
[0010] Thus, there is a need for a new and improved method and
apparatus for providing a strike surface of a golf club which will
overcome the above mentioned deficiencies while providing a better
overall result. Specifically, the present disclosure overcomes the
limitations of the existing attempts through the use of non-obvious
methods.
SUMMARY OF THE DISCLOSURE
[0011] The present disclosure relates to golf clubs and related
sports applications. More particularly, it relates to an enhanced
strike surface of a golf club head, which may be achieved by a
coating applied to the golf club head.
[0012] In the present disclosure a much more significant portion of
the kinetic energy is transferred to the propulsion of the golf
ball forward/upward and a much lower amount of the energy (than
conventional golf clubs) is converted to rotational energy that
spins the ball. This results in an improved launch angle and
greater carry distance than a conventional golf club for any given
clubhead speed at impact and less inadvertent loss of accuracy from
off axis spin of the ball.
[0013] In particular, the present disclosure describes a method for
producing golf clubs that have design features and characteristics
that enhance the directional accuracy, reduce the inadvertent
hooking and slicing and improve the distance performance of a golf
club of given loft angle.
[0014] The present disclosure overcomes the cost and complexity of
such manufacturing techniques and results in a dramatic improvement
in golf club performance.
[0015] Specifically, in accordance with one embodiment of the
disclosure, a modification of the golf clubface is such that the
ball striking surface does not have any grooves. In other words,
the ball striking surface is substantially smooth. The ball
striking surface has an advantageous combination of properties,
such as smoothness, hardness and durability, adapted to improve
golf club performance.
[0016] In another embodiment of the disclosure, the golf clubface
includes a ball striking surface having surface features configured
as one or more ridges or ribs. Alternatively, the one or more
surface features can be configured as one or more grooves. In still
a further embodiment, the one or more surface features can be
configured as a combination of ridges and grooves. The ball
striking surface with surface features has an advantageous
combination of properties, such as smoothness, hardness and
durability, adapted to improve golf club performance.
[0017] In a further embodiment of the disclosure, the ball striking
surface of the clubface is provided by an insert attached to the
clubface. The insert can be substantially smooth or can have
surface features as described above. Moreover, the insert provides
the ball striking surface having an advantageous combination of
properties, such as smoothness, hardness and durability.
[0018] According to one aspect of the aforementioned present
embodiments, the ball striking surface and the clubface can be
integral such that the combination of advantageous properties, such
as smoothness, hardness and durability, are intrinsic to the
clubface and the ball striking surface. According to a second
aspect of the above present embodiments, a coating chosen for its
advantageous combination of properties, such as smoothness,
hardness and durability, can be applied to the clubface. The
clubface and the coating applied thereon define a ball striking
surface having enhanced performance over similar golf clubs without
the benefit of having the coating disclosed herein. The intrinsic
coefficient of friction is not a critical characteristic of the
chosen coating that results in the enhanced performance.
[0019] In one particular embodiment of the disclosure, a clubface
is coated with an oil modified polyurethane to define a ball
striking surface having enhanced performance. The resulting ball
striking surface is superior to PTFE in durability, performance and
cost of manufacture. Modified polyurethane coatings are typically
used for the purpose of corrosion protection of metal surfaces. The
application of these compounds to enhance the performance
characteristics of golf clubs is both non-obvious and
effective.
[0020] In another particular embodiment the golf clubface may be
coated with a baked on porcelain material as used in non-stick
cookware or appliance surfaces. Additionally, a ceramic coating may
also be used to achieve the required surface properties. A powder
coating of polyurethane or other acceptably hard and durable
material may also be used.
[0021] Still other aspects of this disclosure will become apparent
upon reading and understanding of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] For a better understanding of the present invention,
reference may be had to the following detailed description taken in
conjunction with the accompanying drawings in which:
[0023] FIG. 1 is a partial perspective view of a golf club
including a clubface with a ball striking surface having enhanced
performance in accordance with one embodiment of the present
disclosure.
[0024] FIG. 2 is a partial perspective view of a golf club head
which has surface features on the clubface in accordance with
another embodiment of the present disclosure.
[0025] FIG. 3 is a partial perspective view of a golf club head
which has a smooth clubface in accordance with another embodiment
of the present disclosure.
[0026] FIG. 4 is a partial perspective view of a golf club head
which has an insert providing a ball striking surface having
enhanced performance in accordance with another embodiment of the
present disclosure.
[0027] FIG. 5 is a partial cross-sectional view of a layer of
coating disposed on a clubface of a golf club head according one
aspect of the present embodiments.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0028] A preferred embodiment of the present disclosure is a golf
club of low cost manufacture that includes a ball striking surface
able to perform to the above specifications. For a performance
enhancing ball-striking surface to be practical and useful it must
be durable, smooth, resist impact forces of normal use, and reduce
the imparted spin on the golf ball. The USGA requires that the
surface have a hardness that passes the `fingernail test." This
hardness corresponds to a Mohs hardness of 2.5, compared with a
copper penny having a Mohs hardness of 3.0. The intent of this
ruling is to render common lubricants, adhesive patches and other
waxy or liquid substances that may be applied to the striking
surface as non-conforming.
[0029] In contrast, existing methods use surface coatings (PTFE and
its variants) with a specific coefficient of friction. Coefficient
of friction is a complex property that is known to be unpredictable
and can be highly dependent on normal forces at the contact
surfaces as well as being limited by the mechanical properties of
the substances being tested (i.e., hardness, compressive strength,
yield strength, etc.). While PTFE would seem to be a viable
substance to coat a golf club for reduced spin, it has been
determined that, from a practical standpoint, PTFE has fails to be
useful. In particular, PTFE is not sufficiently durable or impact
resistant to satisfy the requirements of a viable surface of a golf
club.
[0030] According to one embodiment of the present disclosure, a
ball striking surface of the clubface is substantially smooth. In
another embodiment, the ball striking surface has of the clubface
has one or more surface features. In another embodiment, the ball
striking surface may be the surface of insert attached to the
clubface of the golf club. The insert may be substantially smooth
or may include one or more surface features. According to one
aspect of the present embodiments, the ball striking surface and
the clubface of the golf club head are integral. In other aspects,
the ball striking surface may be supplied by a coating applied on a
clubface of the golf club head. The ball striking surface of the
golf club satisfying the physical attributes listed below, while
still meeting the physical attributes required by the USGA, will
reduce a spin rate, increase a launch angle, and increase a carry
distance on the golf ball compared with a similar golf club without
the ball striking surface of the present disclosure.
[0031] Specifically, in accordance with the preferred embodiment of
this disclosure, the resulting ball striking surface 18 (see FIGS.
1-5) may include some or all of the following properties:
[0032] a) A hardness of greater than Shore D 65;
[0033] b) A surface roughness Ra of 1.0 micron or less (i.e., a
substantially smooth surface), where Ra is the roughness average of
the ball striking surface's measured microscopic peaks and
valleys;
[0034] c) A wear resistance minimum of zero loss at 1 kg per 1000
Cycles (ASTM-C-501);
[0035] d) A flexural strength of greater than 3000 psi (ASTM
C-580);
[0036] e) An indentation resistance (Mil-D-3134F sec 4.7.4) of
greater than 1500 psi for a duration of 30 minutes;
[0037] f) A tensile strength of greater than 3000 psi (ASTM C-307);
and
[0038] g) A compressive strength of greater than 5000 psi.
[0039] A ball striking surface having a combination of some or all
of properties a)-g) above has been found to dramatically improve
the performance characteristics of a golf ball struck by the ball
striking surface. For example, the hardness and compressive
strength properties of the ball striking surface in combination
with the smoothness prevents the golf ball from developing
significant mechanical engagement with ball striking surface upon
impact with the golf club, thereby reducing the amount of imparted
spin.
[0040] Referring now to FIG. 1, a golf club 10 is shown having a
shaft 12 and a head 14 connected to the shaft in a manner well
known in the art. While the golf club head 14 illustrated in FIG. 1
is shown as being configured for a driver 11 or a "wood" club, it
should be understood that the present disclosure is not necessarily
limited thereto, and other types of golf club heads are also
contemplated (See FIGS. 3-4). The golf club head 14 includes a
clubface 16, which is the surface of the golf club head that faces
an associated golf ball (not shown) as a user prepares to swing the
golf club. At least a portion of the clubface 16 comprises a ball
striking surface 18. The ball striking surface 18 is adapted to
contact an associated golf ball and transfer the kinetic energy of
the golf club to the golf ball. In this regard, the ball striking
surface 18 may comprise substantially all of the clubface 16 of the
golf club head 14, or just a portion thereof (e.g., a centrally
located "sweet spot" of the clubface).
[0041] FIG. 2 illustrates a golf club head 22 which is configured
as an "iron" club. The clubface 16 of the golf club head 22 has a
ball striking surface 18 which includes surface features 24. In one
embodiment, the surface features 24 can be configured as one or
more ridges or ribs. Alternatively, the surface features 24 can be
configured as one or more grooves. In still a further embodiment,
the surface features 24 can be configured as a combination of
ridges and grooves. Other surface features such as punch marks are
also contemplated, and the surface features of the present
disclosure are not limited to the geometry of those illustrated in
FIG. 2. The ridged and/or grooved ball striking surface 18 is
adapted to contact an associated golf ball and transfer the kinetic
energy of the golf club to the golf ball. In this regard, the
ridged and/or grooved ball striking surface 18 of golf club head 22
may comprise just a portion of the clubface 16 or substantially all
of the clubface (e.g., except for perimeter portions of the
clubface), provided the surface features are in accordance with the
Rules of Golf issued by the USGA.
[0042] FIG. 3 illustrates a golf club head 26 which, similar to
golf club head 22 shown in FIG. 2, is also configured as an "iron"
club. However, the clubface 16 of golf club head 26 has a ball
striking surface 18 without any surface features. In other words,
the ball striking surface 18 of head 26 is configured to be
substantially smooth. The substantially smooth ball striking
surface is adapted to contact an associated golf ball and transfer
the kinetic energy of the golf club to the golf ball. In this
regard, the substantially smooth ball striking surface 18 of golf
club head 26 may comprise substantially all of the clubface 16 of
the golf club head 14, or just a portion thereof (e.g., a centrally
located "sweet spot" of the clubface).
[0043] Referring back to FIG. 1, the ball striking surface 18 of
the golf club head 14 can be configured similarly to that of golf
ball heads 22, 26 illustrated in FIGS. 2 and 3, respectfully. That
is, the ball striking surface 18 of the driver golf club head 14
can be configured to have one or more ridges or grooves or be
configured to be substantially smooth.
[0044] FIG. 4 shows a golf club head 30 which is configured as an
"iron" club. However, it should be understood that golf club head
30 could also be configured as a "wood" or driver club without
departing from the scope of the present disclosure. The golf club
head 30 of FIG. 4 differs from those illustrated in FIGS. 1-3 in
that the ball striking surface 18 comprises a separate insert 32
that is completely separate from the rest of the golf club head.
The separate insert 32 can be configured as an overlay insert or an
inlay insert, both of which can be attached to the clubface 16. The
insert 32 can be attached to the clubface 16 in a manner well known
in the art, such as through the use of adhesives or through a
mechanical means such as fasteners, etc. The insert 32 comprising
the ball striking surface 18 is adapted to contact an associated
golf ball and transfer the kinetic energy of the golf club to the
golf ball.
[0045] The embodiment illustrated in FIG. 4 shows the insert 32
being configured as an inlay insert. In this regard, the clubface
16 includes a receiving portion 34 adapted to receive the inlay
insert 32. The inlay insert 32 is attached to the receiving portion
34 in the same manner as discussed above, i.e., through the use of
adhesives or mechanical fasteners known in the art. Generally, when
configured as an inlay, the insert 32 is attached to the clubface
16 to provide the ball striking surface 18 comprising just a
portion of the clubface of the golf club head 30 such as central
portion. In this regard, the receiving portion 34 can be recessed
into the clubface 16 such that the inlay insert 32, and thus the
ball striking surface 18, is substantially flush with the
surrounding portions of the clubface in accordance with the Rules
of Golf issued by the USGA.
[0046] In other embodiments, the separate insert 32 is configured
as an overlay insert (not shown). When the insert 32 is configured
as an overlay, the insert is attached to the clubface 16 to provide
the ball striking surface 18 comprising substantially all of the
clubface of the golf club head 30. In other words, when configured
as an overlay, the entire clubface 16 acts as the receiving portion
for the insert 32 such that the insert completely overlays or
covers the clubface. Again, when configured as an overlay insert,
the insert 32 is attached to the clubface in the same manner as
discussed above, i.e., through the use of adhesives or mechanical
fasteners known in the art.
[0047] The ball striking surface 18 of the separate insert 32
attached to the clubface 16 of golf club head 30 can be configured
similarly to that of golf ball heads 22, 26 illustrated in FIGS. 2
and 3, respectfully. That is, the ball striking surface 18 of the
insert 32 can be configured to have one or more ridges or grooves
or be configured to be substantially smooth.
[0048] In some embodiments, the insert 32 is removably attached to
the clubface 16. Such a configuration allows the insert 32 to be
removed from the clubface 16 whenever desired by the user of the
golf club. After a significant period of use, the ball striking
surface 18 may exhibit a degradation in performance characteristics
due to, for example, the forceful nature of the impact between golf
clubs and golf balls, the presence of debris (e.g., sand, dirt,
grass, etc.), and/or exposure to natural elements (e.g., sunlight,
water, cold air, etc.). As such, a user may want to remove the
insert 32 for reconditioning or replacement of the ball striking
surface 18, thereby saving on costs which might otherwise be spent
on replacing the entire golf club. Moreover, manufacturers over
time may release upgraded or improved inserts and ball striking
surfaces for various golf club models. A removable insert permits a
golf club user to upgrade just the striking surface of the golf
club head, as opposed to the entire golf club.
[0049] In accordance with a preferred embodiment of the disclosure,
the ball striking surface 18 of each of the golf club heads
described above and shown in FIGS. 1-5 has a combination of
properties configured to improve various performance
characteristics associated with the game of golf. These performance
characteristics include but are not limited to an increased launch
angle of the golf ball, a decreased spin rate of the golf ball, and
an increased carry distance (e.g., yardage) of the golf ball. As
mentioned above, the ball striking surface's combination of
properties advantageously improves these performance
characteristics at any given club speed by permitting a much more
significant portion of the kinetic energy to be transferred to the
propulsion of the golf ball forward/upward at impact and a much
lower amount of the energy (than conventional golf clubs) to be
converted to rotational energy that spins the ball. Moreover, less
inadvertent loss of accuracy from off axis spin of the ball is
achieved. Specifically, this combination of properties is achieved
by a ball striking surface having some or all of the properties a)
through g) described previously in this disclosure. Importantly, it
has been found that the intrinsic lubricity of the ball striking
surface 18 is not a required characteristic. In other words, a
particular coefficient of friction of the ball striking surface 18
is not a critical property that results in the enhanced
performance.
[0050] In particular, the properties of hardness, indentation
resistance or compressive strength, and smoothness are preferred. A
ball striking surface with some or all of the properties a) through
g) described above also imparts improved durability, such that the
ball striking surface can withstand repeated forceful golf ball
impacts without a significant degradation in performance (a common
problem with PTFE coatings). The ball striking surface 18 thus
forms a support structure for carrying the force of a golf ball
impact from the clubface 16 to the heads 14, 22, 26, and 30 with
minimal, if any, indentation.
[0051] In accordance with one aspect of the embodiments of the
present disclosure, the ball striking surface 18 and the clubface
16 of the golf club heads 14, 22, 26, and 30 are integral. That is,
the ball striking surface 18 and clubface 16 are included as part
of a whole rather than supplied separately. In such an embodiment,
the advantageous combination of properties disclosed herein is
intrinsic to the clubface and the ball striking surface. This may
be achieved, for example, by manufacturing the golf club head,
clubface, and ball striking surface from the same material having
the advantageous combination of properties. As another example, a
surface treatment could be performed on the clubface to form the
ball striking surface with the combination of properties, such as
through a surface hardening or work hardening process known in the
art.
[0052] FIG. 5 illustrates another aspect of the embodiments of the
present disclosure, wherein the clubface 16 of the golf club head
14 is supplied with a separate component which provides the ball
striking surface 18 having the advantageous combination of
properties presently disclosed. In particular, the separate
component is one or more layers of a coating 20 disposed on at
least a portion of the clubface 16 of golf club head 14 to form a
ball striking surface 18. The coating 20 can comprise multiple
layers at any desired thickness t to form the ball striking surface
18 with the advantageous combination or properties. The coating 20
is a substance chosen for having the advantageous combination or
properties discussed herein, including smoothness, hardness and
durability. However, the intrinsic coefficient of friction is not
the critical characteristic of the chosen coating that results in
the enhanced performance.
[0053] The coating 20 forming the ball contacting surface 18 is
adapted to impact an associated golf ball and transfer the kinetic
energy of the golf club to the golf ball. In this regard, the ball
striking surface 18 comprising the coating 20 may comprise
substantially all of the clubface 16 of the golf club head 14, or
just a portion thereof. For example, the coating 20 can be applied
at a centrally located "sweet spot" of the clubface, or could be
applied to cover the entire clubface. Moreover, while golf club
head 14 is illustrated in FIG. 5 as receiving the coating 20, it
should be understood that any of the golf club heads discussed
herein could similarly receive the coating without departing from
the scope of the present disclosure, including heads 22, 26, and 30
illustrated in FIGS. 2, 3, and 4, respectively.
[0054] If the coating 20 is applied to head 22 of FIG. 2, the
surface features 24 can already be formed on the clubface 16 such
that the coating is disposed over the surface features to form the
ridged and/or grooved ball striking surface 18 of the golf club
head. Alternatively, the coating 20 can be applied to the clubface
16 such that the coating itself forms the surface features 24 of
golf club head 22.
[0055] Referring now to golf club head 30 of FIG. 4, the coating 20
can be applied to the insert 32 to form the ball striking surface
18. In this regard, the insert 32 may further comprise a substrate
(not shown) and the coating 20 is applied to at least a portion of
the substrate. The substrate of the insert 32 and the clubface 16
of the golf club head 30 can be made from the same or different
materials. However, when the insert 32 is configured as an inlay
insert as described above, the coating 20 is applied to the
substrate of the insert such that when the insert is attached to
the clubface 16, the ball striking surface 18 formed by the coating
is still substantially flush with the surrounding portions of the
clubface in accordance with the Rules of Golf issued by the USGA.
When the insert 32 is configured as an overlay insert as described
above, the coating 20 is applied to the entire substrate of the
insert to provide a ball striking surface 18 which entirely covers
the clubface 16. Moreover, in an alternative embodiment, the insert
32 is provided without a coating, but made from a material
different than that of the clubface 16. In this regard, the
different material of the insert can intrinsically provide the ball
striking surface with the advantageous combination of properties
disclosed herein.
[0056] With reference back to FIG. 5, in some particular
embodiments the coating 20 material is a polymeric isocyanate
derivative such as polyurethane, including modified polyurethanes
like oil modified polyurethane. A polyurethane coating 20 is
applied at a suitable thickness t to provide the advantageous
combination of properties disclosed herein, including a range of
about 100 .mu.m to about 200 .mu.m, and preferably about 115 .mu.m
to about 185 .mu.m, and more preferably about 125 .mu.m to about
185 .mu.m. When the coating 20 is applied as one or more layers,
the thickness of the one or more layers comprising the coating is
preferably maintained within the aforementioned range. A coating
material which is commercially available under the trade
POR-15.RTM. is presently preferred for use. The application of ball
striking surfaces comprising the POR-15.RTM. coating, a coating not
known for its low coefficient of friction nor commonly used in
connection with golf clubs, unexpectedly enhanced the performance
characteristics of golf clubs, as shown in the Example below.
[0057] A process for applying the polyurethane coating 20 to the
clubface 16 or insert 32 of a golf club will now be described. If a
substantially smooth ball striking surface is desired, an optional
first step is to smooth out the clubface or insert by removing any
unwanted surface features and roughness on the clubface by
techniques know in the art, including grinding, sanding, etc., and
the like. If the clubface or insert is to include surface features,
or is already prepared to an adequate smoothness, a surface
preparation step is first performed. The surface preparation step
involves removing all visible oil, grease, soil, dirt, and other
contaminants from the golf club head. Surface preparation can also
include an acid etching step known in the art to clean the clubface
or insert. The coating can then be disposed on the clubface or
insert using known application techniques, such as spraying,
airless spraying, brushing, or rolling. Additional layers of
coating are then applied as desired, allowing each preceding coat
to dry for approximately 1 to 2 hours before application of
subsequent coat layers. In some particular embodiments, 3 to 4
layers of coating has been found to impart the advantageous
combination of properties to the ball striking surface of the golf
club heads disclosed herein. Once the desired number of coating
layers is applied, the coating should be allowed to cure for
approximately one day.
[0058] A coating comprising modified polyurethane provides a ball
striking surface 18 superior to PTFE in durability, performance and
cost of manufacture. Modified polyurethane coatings are typically
used for the purpose of corrosion protection of metal surfaces. The
application of these compounds to enhance the performance
characteristics of golf clubs is both non-obvious and
effective.
[0059] It is contemplated that other coatings and materials can be
used and applied to the clubface to provide a ball striking surface
having the advantageous combination of properties disclosed herein.
For example, the golf clubface may be coated with a baked on
porcelain material as used in non-stick cookware or appliance
surfaces. Additionally, a ceramic coating may also be used to
achieve the required surface properties. A powder coating of
polyurethane or other acceptably hard and durable material may also
be used.
[0060] Moreover, even though FIGS. 1-5 illustrate and the above
disclosure describes a preferred embodiment of a golf club
providing a clubface 16 and a ball striking surface 18, it is
contemplated that, without deviating from the scope of the present
disclosure, other items of sports equipment can provide a face
having a striking surface with the advantageous combination of
properties disclosed herein. For example, other types of sports
equipment that may similarly benefit from enhanced surface strike
performance due to the advantageous combination of properties
disclosed herein include, but are not limited to, baseball bats,
hockey sticks, polo mallets, croquet mallets bocce balls, bowling
balls, billiard balls, etc., and the like. These additional types
of sports equipment can include the combination of properties
intrinsically or through the use of coatings and/or inserts as
discussed above.
[0061] The following example is provided to illustrate the
processes of the present disclosure. The example is merely
illustrative and is not intended to limit the disclosure to the
materials, conditions, or process parameters set forth therein.
Example
[0062] Tests were performed to show the advantage of utilizing a
ball striking surface having the advantageous combination of
properties disclosed herein, including hardness, smoothness, and
durability. Various performance characteristics associated with the
game of golf can be improved through the use of the ball striking
surface having this advantageous combination of properties. Such
performance characteristics include an increased launch angle of
the golf ball, a decreased spin rate of the golf ball, and an
increased carry distance (e.g., yardage) of the golf ball.
[0063] Two golf clubs of the same type and brand were acquired. In
particular, two Callaway.RTM. 9-irons were used, each having a
39.degree. loft. One of the golf clubs was modified to have the
ball striking surface disclosed herein for comparison with the
other golf club, which was left unmodified. To provide the modified
golf club with the ball striking surface, a coating of polyurethane
material commercially available under the trade name POR-15.RTM.,
and having the advantageous combination of properties disclosed
herein, was used. POR-150 was coated on the clubface of the
modified golf club in accordance with the method discussed
above.
[0064] Numerous golf balls of the same brand were struck with the
modified and unmodified golf clubs and various measurements were
recorded. Using a FlightScope.RTM. ball tracking monitor, radar,
and launch monitor, the golf ball carry distance, golf ball speed,
club speed, golf ball spin rate, and golf ball launch angle were
recorded for each golf shot with the modified and unmodified golf
club. The shots were taken outside to simulate real-world
conditions, and the data was collected for the full flight of the
ball. In other words, the carry distances of the golf balls was
actually measured and not extrapolated from initial launch
conditions. The results are presented in Table 1 below:
TABLE-US-00001 TABLE 1 Performance Measurements of Modified and
Unmodified Golf Club Carry Ball Club Spin Launch Shot (yds) (mph)
(mph) (rpm) V (.degree.) Modified Golf Club 3 165.6 102.6 89.1 2965
29.9 4 171.6 106.1 86.9 2797 30.5 5 163.8 105.7 94.5 2553 27.5 6
150 95.8 87.8 2398 32.6 Average 162.75 102.55 89.575 2678.25 30.125
Unmodified Golf Club 14 134.1 104.3 85.5 7924 25.3 15 133.5 106.8
85.8 8168 28.6 16 127.1 98.3 90.2 6368 28.7 17 132 102.5 86.7 6082
29.1 Average 131.675 102.975 87.05 7135.5 27.925
[0065] As shown in Table 1 above, the modified club produced
between about 16 yards to about 45 yards increased carry distance
and an average increased carry distance of over 30 yards compared
with the unmodified golf club, with no significant increase in ball
velocity. In addition, the launch angle achieved by the modified
golf club increased by as much as about 7 degrees, with an average
launch angle increase of about 2 degrees compared with the
unmodified golf club. Moreover, the modified golf club decreased
spin rate by as much as about 70%, with an average decrease in spin
rate of about 60% compared with the unmodified golf club. In
summary, the results in Table 1 show that a ball striking surface
having a combination of properties a)-g) disclosed above will
increase the launch angle of the struck ball and reduce the spin
rate. As a result, longer and higher ball flight, less lateral
dispersion of an incorrectly struck ball, and a more beneficial
descent angle are achieved.
[0066] The improved performance characteristics achieved by the
modified golf club is attributed to the ball striking surface
having the advantageous combination of properties disclosed herein.
For example, properties such as hardness and resistance to
indentation of the ball striking surface, in combination with the
smoothness, prevents the golf ball from developing significant
mechanical engagement with ball striking surface upon impact with
the golf club, thereby reducing the amount of imparted spin.
Because less kinetic energy is converted to rotational energy that
spins that ball, a much more significant portion of the kinetic
energy is transferred to the forward/upward propulsion of the golf
ball, thereby improving the launch angle and increasing the carry
distance. The application of ball striking surfaces having this
combination of properties to enhance the performance
characteristics of golf clubs is un-expected, effective, and
non-obvious.
[0067] The exemplary embodiment has been described with reference
to the preferred embodiments. Obviously, modifications and
alterations will occur to others upon reading and understanding the
preceding detailed description. It is intended that the exemplary
embodiment be construed as including all such modifications and
alterations insofar as they come within the scope of the above
disclosures or the equivalents thereof.
* * * * *