U.S. patent application number 09/843239 was filed with the patent office on 2002-01-10 for diamond-like carbon coated golf club head.
This patent application is currently assigned to Kinik Company. Invention is credited to Lin, Frank S., Pai, Y. L., Sung, Chien-Min.
Application Number | 20020004426 09/843239 |
Document ID | / |
Family ID | 23102044 |
Filed Date | 2002-01-10 |
United States Patent
Application |
20020004426 |
Kind Code |
A1 |
Lin, Frank S. ; et
al. |
January 10, 2002 |
Diamond-like carbon coated golf club head
Abstract
A diamond-like carbon (DLC) coated golf club head primarily for
reduction of friction between the hitting surface and the golf ball
at impact. The DLC coating comes in two varieties including
dehydrogenated DLC or hydrogenated DLC and is thinly applied
between about 0.1 and 10 .mu.m. The diamond particle size of
individual diamond-like carbon molecules or crystals can be less
than 0.1 .mu.m, and preferably less than 1 nanometer. The DLC
coating may be bonded to the golf club head or hitting surface
using cathodic arc method or other applicable methods at
temperatures of less than 200.degree. C.
Inventors: |
Lin, Frank S.; (Taiwan,
CN) ; Pai, Y. L.; (Ying-Ko, TW) ; Sung,
Chien-Min; (Tansui, TW) |
Correspondence
Address: |
THORPE NORTH WESTERN
8180 SOUTH 700 EAST, SUITE 200
P.O. BOX 1219
SANDY
UT
84070
US
|
Assignee: |
Kinik Company
|
Family ID: |
23102044 |
Appl. No.: |
09/843239 |
Filed: |
April 25, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09843239 |
Apr 25, 2001 |
|
|
|
09287241 |
Apr 7, 1999 |
|
|
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Current U.S.
Class: |
473/324 |
Current CPC
Class: |
A63B 53/04 20130101;
A63B 53/0466 20130101; A63B 60/00 20151001; A63B 53/0416 20200801;
A63B 2209/00 20130101 |
Class at
Publication: |
473/324 |
International
Class: |
A63B 053/04 |
Claims
What is claimed is:
1. A golf club head comprising: a body having a hitting surface
wherein said hitting surface is coated with from 0.1 .mu.m and 10
.mu.m of diamond-like carbon (DLC) coating, and wherein said
diamond-like carbon (DLC) of said coating has a grain size less
than 0.1 .mu.m.
2. A golf club head as in claim 1 further comprising a lower
surface, said lower surface being coated with from 0.1 .mu.m and 10
.mu.m of diamond-like carbon (DLC) coating, and wherein said
diamond-like carbon (DLC) of said coating has a grain size less
than 0.1 .mu.m.
3. A golf club head as in claim 1 wherein said diamond-like carbon
(DLC) comprises distorted tetrahedral carbon.
4. A golf club head as in claim 1 wherein said diamond-like carbon
(DLC) of said coating has a grain size less than 1.0 nanometer.
5. A golf club head as in claim 1 as in claim 2 wherein the hitting
surface coating and the bottom surface coating is a single
continuous coating, and is not present elsewhere on the golf club
head.
6. A golf club head as in claim 1 wherein the diamond-like carbon
(DLC) coating extends from the hitting surface to another part of
the head.
7. A golf club head as in claim 1 wherein the hitting surface has a
frictional coefficient of less than 0.1.
8. A golf club head as in claim 1 wherein said golf club head is
comprised primarily of material selected from the group consisting
of iron and titanium.
9. A golf club head as in claim 1 wherein said diamond-like carbon
(DLC) contains less than 10% (by atoms) hydrogen.
10. A golf club head as in claim 9 wherein said coating of said
diamond-like carbon (DLC) is from 50% to 95% (by atoms)
diamond.
11. A golf club head as in claim 10 wherein said coating containing
said diamond-like carbon (DLC) is from 80% to 95% (by atoms)
diamond.
12. A golf club head as in claim 1 wherein said coating containing
said diamond-like carbon (DLC) contains at least 10% (by atoms)
hydrogen.
13. A golf club head as in claim 12 wherein said coating containing
said diamond-like carbon (DLC) is from 20% to 60% (by atoms)
diamond.
14. A golf club head as in claim 13 wherein said coating containing
said diamond-like carbon (DLC) is from 30% to 60% (by atoms)
diamond.
15. A golf club head as in claim 1 wherein said diamond-like carbon
(DLC) is deposited to said hitting surface by physical vapor
deposition method (PVD).
16. A golf club head as in claim 15 wherein said physical vapor
deposition method (PVD) is cathodic arc method.
17. A golf club head as in claim 12 wherein said diamond-like
carbon (DLC) is deposited to said hitting surface at a temperature
less than 200.degree. C.
18. A golf club head as in claim 1 wherein the diamond-like carbon
(DLC) comprises diamond, graphite, and a hydrocarbon plastic.
19. A golf club head as in claim 1 wherein the diamond-like carbon
(DLC) comprises diamond and a hydrocarbon plastic.
20. A golf club head as in claim 1 wherein the diamond carbon atoms
and the graphite carbon of the diamond-like carbon (DLC) coating
are randomly assembled, forming an amorphous coating structure.
Description
[0001] The present application is a continuation-in-part
application based on a U.S. patent application filed on Apr. 7,
1999, and having the Ser. No. 09/287,241.
FIELD OF THE INVENTION
[0002] The present invention relates generally to improvements in
the performance of a golf club, especially golf clubs used for
distance. More specifically, the invention relates to the coating
of the face or hitting surface of a golf club head with
diamond-like carbon (DLC) to drastically reduce the frictional
coefficient on the face of the golf club head, thereby increasing
golf ball distance and accuracy.
BACKGROUND OF THE INVENTION
[0003] Golf is a very popular sport among people of all ages. As
such, the golf equipment industry is constantly seeking to improve
the design of golf equipment, especially golf clubs, to meet the
demands of many golfers trying to improve their game or obtain a
competitive edge over fellow golfers. There have been numerous
attempts over the years to improve the performance of golf clubs
and indeed, this continues today.
[0004] Essentially, the game of golf can be broken down into two
major skills, the long game and the short game. The long game
involves skills such as "driving" a golf ball long distances from
the tee box and/or hitting a golf ball long distances from the
fairway. The short game involves skills such as "pitching" a golf
ball from a location near the putting green and "putting" the golf
ball from a spot on the green into a hole. Since the skills
utilized in the long game and the short game are different, club
designs vary accordingly, i.e., a putter is designed differently
than a driver.
[0005] When considering how one might improve the performance of a
golf club, there are essentially two major variables that should be
considered. First, the properties of the shaft may be considered
when seeking to increase performance of a golf club. For example,
golf club shafts have traditionally been designed using metal
materials. However, there has been a recent trend toward the use of
graphite shafts. Additionally, the shaft length and/or the angle
relationship between the shaft and the golf club head may be
modified to alter performance. These latter two alterations are
typically made when a person wishes to have their clubs
customized.
[0006] Second, and more applicable to the present invention, the
design of the golf club head itself effects the performance of a
given club. Particularly when using clubs such as drivers and other
long game clubs, the distance and direction that a golf ball
travels is critical. As a result, many different geometric shapes
and materials have been tried in order to vary the design of golf
club heads in hope of achieving high performance, i.e., increased
distance and improved accuracy.
[0007] Regarding geometric shape of golf club heads, many different
shapes have been manufactured. For example, there has been a recent
trend toward the design of driver heads with increased volume.
Additionally, clubs commonly called "irons" have evolved from
having solid golf club heads to golf club heads having perimeter
weighting. Perimeter weighted golf club heads have many advantages
over older clubs including increased distance and increased control
of a golf shot.
[0008] Regarding the material used to construct golf club heads,
many materials have been used including hard wood (e.g.,
persimmon), metal (e.g., steel, cast iron, aluminum, copper,
titanium), graphite (e.g., Thunder Head wood from Spalding.RTM.),
plastic (e.g., Odyssey as described in U.S. Pat. No. 5,342,812
issued to G. Rennie) or other materials (e.g., metal matrix
composite as described in U.S. Pat. No. 8,342,812 issued to P.
Niskanen et. al.). Presently, drivers are primarily made from
titanium or iron.
[0009] An important part of a golf club is the face of the club
head. The face of the club head can best be described as the
hitting spot or surface. This is where the golf club interfaces
with the golf ball during a golf swing. When a golf ball is struck,
the material at the contact point or hitting surface will deform
elastically and then rebound immediately. Though this cannot be
entirely prevented, reduction of this deformation is desirable so
that the energy of the swing can be more effectively transferred to
the golf ball. As a result, many attempts have been made to improve
the rigidity of the material used in golf club heads. This is
particularly true with regard to the face or hitting surface of the
golf club head.
[0010] When considering materials with high rigidity, one candidate
to consider is diamond. In U.S. Pat. Nos. 4,951,953 and 5,029,865
issuing to D. Kim, a ball striking surface of a golf club head is
disclosed having diamond coating for increased surface rigidity.
The particles can be embedded using an electroless "composite
diamond coating" technique. Specifically, the patent claims the use
of a composite comprising a diamond component and a metal or metal
alloy such as a nickel matrix. The entire thickness of the
composite coating can be from 1 to 2 mils. Alternatively, in U.S.
Pat. No. 5,620,382 issuing to H. Sam Cho, et al., the use of a
polycrystalline diamond or cubic boron nitride insert is disclosed.
The insert is comprised of a surface layer (bonded diamond-diamond
or CBN-CBN crystals) and a hard or rigid support layer. The insert
is then inserted, i.e., cemented in a metal or ceramic matrix, into
a cavity on the golf club head.
[0011] Though diamond has the highest modulus of rigidity, there
are some basic problems with the use of diamond or diamond powder
in general. First, because the hitting surface is so hard, there is
very little deformation of the club head creating a greater impact
force. As a result, the golf ball, which is much softer than the
club, experiences more ovalation than is typically experienced.
Thus, the contact area between the hitting surface of the club head
and the golf ball is increased momentarily. Because the contact
area is increased, the frictional force between the hitting surface
of the club head and the golf ball is also increased. In other
words, because there is more contact between the golf ball and the
hitting surface, there is more friction. Moreover, there are
additional problems when a diamond-metal composite is used in that
diamond is much harder than metal. Therefore, when a diamond-metal
composite is polished, diamond grains, being more rigid than metal,
will not wear down at the same rate as metal thereby causing the
diamond grains or particles to protrude higher than the metal
matrix after polishing. This unevenness will further increase the
frictional force between the hitting surface of the club head and
the golf ball.
[0012] Higher frictional force between the hitting surface and the
golf ball is generally undesirable because unless the golf ball is
perfectly hit, there is a greater likelihood of "hooking" or
"slicing" a given shot. "Hook" and "slice" are golf terms used to
describe the direction a golf ball travels when the path of flight
is not linear, but arcuate in a direction toward or away from the
golfer respectively. This occurs as the golf ball spins on a more
vertical axis. Therefore, the higher the spin rate, the more
curvature, i.e., "hook" or "slice", the flying ball will
experience. These type of shots are normally undesirable for two
reasons. First, the distance that the golf ball travels is reduced
because energy is wasted on angular momentum, i.e., spin, and heat
generated from the increased friction. Both of these energies
reduce the desired forward momentum. Second, since the desired
direction is compromised, the next shot becomes more difficult.
Additionally, though back spin is desirable for some shots, even
back spin will diminish the distance of a golf shot.
[0013] With regard to diamond hitting surfaces of club heads, there
are also economic concerns. The preparation of diamond-metal
composite (PCD) requires somewhat difficult and expensive
modifications of a golf club. First, in order to insert a composite
into a club head, the hitting surface must be machined to create a
cavity or void for insertion of the diamond-metal composite.
Additionally, diamond-metal composite is expensive and the process
of preparation is tedious making this option unaffordable to most
golfers. Moreover, the hitting surface of a club head containing a
diamond-metal composite requires frequent polishing and/or
grinding. This additional work is time consuming and difficult to
accomplish due to the presence of diamond.
[0014] In addition to issues surrounding rigidity, attempts have
also been made to reduce the friction on golf club heads. For
example, U.S. Pat. No. 5,885,171 issuing to Sharpe on Mar. 23, 1999
discloses a system for altering the friction coefficient between a
golf club face and a golf ball. This patent teaches that a liquid
coating, such as a lubricant, can be applied to the face or hitting
surface of a golf club to lower the frictional coefficient. Though
the goal of lowering the frictional coefficient is worthy, there
are several disadvantages to the system disclosed in U.S. Pat. No.
5,885,171. First, applying a liquid lubricant is messy and if the
golfer is not careful, the lubricant can get on the golfer's hands
causing slippage on subsequent swings. Second, some lubricant will
surely pass from the golf club head to the ball causing the ball to
fly through the air unevenly. Third, many golf shots necessarily
require that the golf club strike the substrate or earth prior to
hitting the golf ball. As such, some lubricant will be wiped from
the club prior to striking the ball. Finally, it is inconvenient to
be required to apply a liquid lubricant to a golf club prior to a
golf shot, and further, be required to remove the same lubricant
from the golf club head when completing a golf round.
[0015] A second example of a patent that discusses the reduction of
friction on a golf club head can be found in U.S. Pat. No.
5,531,444 issuing to Buettner on Jul. 2, 1996. In that patent, a
coating of titanium nitride as applied to a golf club head is
disclosed. The patent states that the coating of titanium nitride
provides a "very hard, tough, and low-friction coating." However,
to coat a metal golf club head with titanium nitride, high
temperatures must be used. The patent further states that
precautions must be taken to prevent the golf club head from
deforming or distorting, i.e., "the bore in the club head hozzle
tends to distort." As such, the patent claims a method to prevent
distortion of the club head hozzle. Though the inventor has
succeeded at preventing distortion of the "club head nozzle," the
development of a superior coating is desirable that has a lower
friction coefficient and does not require high temperatures to
apply, thereby preventing distortion and/or weakening the golf club
head.
[0016] It has been recognized that it would be desirable to provide
a golf club head that is relatively inexpensive to manufacture, is
reasonably rigid at the hitting surface, does not distort when a
coating is applied, and drastically reduces the frictional force
between the hitting surface and the golf ball on impact.
SUMMARY OF THE PRESENT INVENTION
[0017] The present invention pertains primarily to an improved golf
club, more particularly, an improved golf club head. The golf club
head of the present invention is comprised of a body having a
hitting surface and a coating of diamond-like carbon (DILC). The
diamond-like carbon (DLC) is used to coat a golf club head,
particularly the hitting surface but including the lower surface,
at a thickness of between about 0.1 and 10 .mu.m. Additionally, the
diamond-like carbon (DLC) of the coating can have a grain size or
diamond molecule size of less than 0.1 .mu.m. Larger diamond grain
sizes can increase the friction between the golf club head hitting
surface and the ball to less desirable levels compared to those of
the present invention. Preferably, the present invention is
intended to coat iron and/or titanium golf club heads, though golf
club heads made from different materials or composites can also be
used.
[0018] Regarding the diamond-like carbon coating, there are
essentially two types that may be used in the present invention.
First, diamond-like carbon (DLC) containing less than 10% (by
atoms) of hydrogen may be used (hereinafter "dehydrogenated DLC").
If dehydrogenated DLC is used, the percentage of diamond in the
diamond-like carbon (DLC) will be from 50% to 95% by atoms. A more
preferred percentage range of diamond is from 80% to 95% by atoms.
Second, diamond-like carbon (DLC) containing at least 10% by atoms
of hydrogen may be used (hereinafter, "hydrogenated DLC"). If
hydrogenated DLC is used, the percentage of diamond in the
diamond-like carbon will be from 20% to 60%. A more preferred
percentage range of diamond is from 30% to 60% by atoms.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In the accompanying drawings which illustrate embodiments of
the invention:
[0020] FIG. 1 is a perspective view of a golf club head indicating
the preferred locations for coating; and
[0021] FIG. 2 is a cross-sectional view of a golf club head coated
in various areas with a diamond-like carbon (DLC)
DETAILED DESCRIPTION OF THE INVENTION
[0022] Before the present invention is disclosed and described, it
is to be understood that this invention is not limited to the
particular process steps and materials disclosed herein as such
process steps and materials may vary to some degree. It is also to
be understood that the terminology used herein is used for the
purpose of describing particular embodiments only and is not
intended to be limiting as the scope of the present invention will
be limited only by the appended claims and equivalents thereof.
[0023] It must be noted that, as used in this specification and the
appended claims, singular forms of "a," "an," and "the" include
plural referents unless the content clearly dictates otherwise.
[0024] In the accompanying drawings, FIG. 1 shows a perspective
view of a golf club head 10 having a diamond-like carbon (DLC)
coated hitting surface 12. Additionally, a diamond-like carbon
(DLC) coated lower surface 14 is shown. Turning to FIG. 2, a
cross-sectional view of the golf club head 10 is shown. Both a
diamond-like carbon (DLC) coated hitting surface 12 and a
diamond-like carbon (DLC) coated lower surface 14 are shown as
adhered to a body 16 of the golf club head 10.
[0025] With these figures in mind, the present invention is drawn
to a golf club head comprising a body having a hitting surface
wherein the hitting surface is coated with from 0.1 .mu.m and 10
.mu.m of diamond-like carbon (DLC) coating, and wherein the
diamond-like carbon (DLC) of the coating has a grain size or
molecule size of less than 0.1 .mu.m. In one embodiment, a lower
surface is also coated with from 0.1 .mu.m and 10 .mu.m of
diamond-like carbon (DLC) coating. There, the diamond-like carbon
(DLC) of the coating can also have a grain size of less than 0.1
.mu.m. Thus, practically speaking, when diamond is present, the
lower end of the particle size (with respect to both the hitting
surface and the bottom coating) can be as small as a single
tetrahedral carbon molecule dimension. In one embodiment where the
bottom surface is coated, the hitting surface coating and the
bottom surface coating can be a single continuous coating. In this
embodiment, the rest of the golf club or golf club head need not be
coated likewise, though such coating is not prohibited. In another
embodiment, the diamond-like carbon (DLC) coating can extend from
the hitting surface to another part of the head.
[0026] Though the grain size or molecule size can be as large as
less than 0.1 .mu.m, it is preferred that the diamond-like carbon
(DLC) of the coating have a grain size of less than about 1
nanometer. In a more specific embodiment, the diamond-like carbon
(DLC) grain size can be amorphous, also known as distorted
tetrahedral carbon.
[0027] With the present invention, the coating can be applied to a
metal golf club head. Though other composites can also be used,
metal golf club heads such as iron or titanium are preferred for
this invention. Further, though the entire golf club head can be
coated with diamond-like carbon (DLC), the hitting surface must be
coated with diamond-like carbon (DLC) for the invention to have the
desired effect with respect-to the golf ball. However, it may be
desirable to coat other surfaces, such as the bottom surface, to
reduce friction as the golf club head brushes the grass, dirt or
other substrates.
[0028] Generally, diamond-like carbon (DLC) is essentially a
composite of diamond, graphite or non-diamond carbon, and/or a
polymer. More specifically, diamond-like carbon (DLC) is a
composite material that can comprise three end members. First,
diamond which is carbon bound together with sp.sup.3 bonds
(tetrahedral) can be present. Second, graphite which is carbon
bound together with sp.sup.2 bonds (triagonal) can be present.
Third, a polymer such as a hydrocarbon plastic can be present as
well. Thus, the carbon portion is substantially supplied by
graphite and/or diamond, and the hydrogen is substantially provided
by the polymer. In one embodiment, the diamond-like carbon (DLC)
coating can comprise diamond, graphite, and a hydrocarbon plastic.
In an alternative embodiment, the diamond-like carbon (DLC) coating
can comprise diamond and a hydrocarbon plastic. In yet another
embodiment, the diamond-like carbon (DLC) coating comprises
randomly assembled diamond carbon atoms and graphite carbon atoms,
thus forming an amorphous coating structure.
[0029] For practical purposes, diamond-like carbon (DLC) can be
divided into two major categories. The first category includes
those diamond-like carbons (DLC) that contain at least 10% hydrogen
by atom, i.e., hydrogenated DLC having more polymer present. The
second category are those diamond-like carbons (DLC) that contain
less than about 10% hydrogen by atom, i.e., dehydrogenated DLC
having less hydrogen present. The hydrogenated DLC contains from
20% to 60% diamond by atom whereas dehydrogenated DLC contains from
50% to 95% diamond by atom.
[0030] As stated, carbon may form either sp.sup.2 bonds or sp.sup.3
bonds. sp.sup.2 bonds indicate the presence of graphite and
sp.sup.3 bonds indicate the presence of diamond. The ratio of these
two types of bonds may be measured by Raman spectroscopy which is
well known in the art. This is significant because the number of
sp.sup.3 bonds (diamond) determines the closeness of diamond-like
carbon (DLC) to diamond. Thus, hydrogenated DLC is less rigid or
hard than dehydrogenated DLC. Though this is the case, all
diamond-like carbons (DLC) have a very low frictional coefficient.
However, the frictional coefficient of hydrogenated DLC increases
in the presence of water or moisture. Conversely, dehydrogenated
DLC is less affected by moisture. Therefore, wet conditions from
rain or humidity will not adversely affect the performance of golf
club heads coated with dehydrogenated DLC. As a result,
dehydrogenated DLC is preferred for the present invention, although
hydrogenated DLC can also be used.
[0031] To utilize the present invention, at least one layer of
diamond-like carbon (DLC) can be coated on the face or hitting
surface of the golf club head. As mentioned, other surfaces can
also be coated as needed, e.g., the lower or bottom surface of the
golf club head may be coated so that the club head brushes the
substrate with reduced friction whereas the upper or top surface
need not be coated. Additionally, when applying a layer of
diamond-like coating (DLC) to the golf club head, the coating can
be deposited directly on the desired surface, e.g., the hitting
surface and/or the bottom surface. Therefore, it is not necessary
to form a cavity or otherwise alter the shape or texture of the
golf club head as is required by some of the prior art.
[0032] The coating of metal substrates with diamond-like carbon
(DLC) is not a new concept. Specifically, industry has deposited
diamond-like carbon (DLC) onto various materials using primarily
physical vapor deposition (PVD). This method energizes carbon atoms
at low temperatures by physical means. Physical vapor deposition
(PVD) is contrasted to chemical vapor deposition (CVD) which
energizes carbon atoms by heating them to a high temperature, i.e.
above 600.degree. C. Due to the high temperatures required for CVD,
PVD is the method of applying diamond-like carbon (DLC) that is
preferred. Specifically, PVD methods known in the art include
techniques such as sputtering, ion beam deposition, and cathodic
arc (though cathodic arc is a more preferred deposition method for
the present invention). However, the mentioning of these methods is
not intended to limit the invention as other methods used for
coating golf club heads with diamond-like carbon (DLC) are
possible.
[0033] One reason that the use of diamond-like carbon (DLC) on the
hitting surface of a golf club head is desirable, especially with
respect to long game golf clubs, is that diamond-like carbon (DLC)
has a very low frictional coefficient, i.e., 0.1 or less. This low
frictional coefficient is comparable to teflon or other lubricants.
Low friction between the hitting surface of a golf club head and
the golf ball reduces heat and spin or angular momentum that a golf
ball normally experiences after impact. Therefore, more forward or
directional momentum is transferred from the golf club to the golf
ball. In other words, the force behind a golf club swing is not
wasted on angular momentum or generated heat.
[0034] Another advantage of the present invention is that to obtain
a low frictional coefficient, the user is not required the use of a
liquid lubricant as discussed in U.S. Pat. No. 5,885,171. The use
of a liquid lubricant can be messy and if the golfer is not
careful, the lubricant can get on the golfer's hands causing
slippage on subsequent golf swings. Further, since the lubricant is
not integrated into the golf club head, some lubricant will pass
from the golf club head to the ball. This will cause the ball to
fly unevenly or asymmetrically. The present invention provides a
golf club head having a low friction coefficient (0.1 or less) on
the hitting surface without the disadvantages associated with the
use of lubricants.
[0035] Still another advantage of the present invention is that the
diamond-like carbon (DLC) can be deposited on the golf club head or
hitting surface at a relatively low temperature, i.e., less than
200.degree. C. This is significant because the properties of the
base metal, i.e., substance that the golf club head is made of,
will not be overheated causing alterations to the dimension or
properties of the golf club head. Therefore, applying the
diamond-like carbon (DLC) to a titanium or iron golf club head will
not adversely affect the shape, relative strength or hardness of
the golf club head. Further, the present invention addresses the
issues presented in the previous discussion of U.S. Pat. No.
5,531,444 by providing a coating (DLC) that can be applied at a
relatively low temperature. As such, the bore in the golf club head
hozzle will not distort during the coating process. Additionally,
since diamond-like carbon (DLC) is a relatively smooth substance,
polishing of the respective golf club heads is minimized if not
eliminated where the diamond-like carbon (DLC) has been
applied.
EXAMPLE
[0036] 50 titanium drivers were coated with dehydrogenated DLC
using the cathodic arc method. The deposited amorphous or distorted
tetrahedral diamond was applied at a thickness of about 3
micrometers. The clubs, having diamond-like carbon (DLC) coated
heads, were used by many golfers. Most felt that their golf
performance, in particular, their driving distance (due in part to
lower degree of hook and slice) had noticeably improved when using
diamond-like carbon (DLC) coated golf club heads.
[0037] While the invention has been described with reference to
certain preferred embodiments, those skilled in the art will
appreciate that various modifications, changes, omissions and
substitutions can be made without departing from the spirit of the
invention. It is intended, therefore, that the invention be limited
only by the scope of the following claims.
* * * * *