WO1997020961A1

WO1997020961A1 - Method for coating a golf club striking surface

Info

Publication number: WO1997020961A1
Application number: PCT/US1996/019360
Authority: WO
Inventors: Michael S. Berlant
Original assignee: Black Ice Golf Company, L.L.C.
Priority date: 1995-12-06
Filing date: 1996-12-06
Publication date: 1997-06-12

Abstract

A method for applying a coating to the striking surface of a golf club to improve the performance of a golf ball. The process includes texturing the striking surface using a grit or sand blasting technique. An optional priming coat is then applied by spraying the surface with a ceramic material. After priming, a ceramic compound is heated to a molten state and spray applied to the striking surface. The molten compound, once sprayed onto the striking surface, fuses to the striking surface to form a hard coating with a porous coating surface that is essentially wear-resistant, is low in abrasiveness, yet has a high coefficient of friction.

Description

METHOD FOR COATING A GOLF CLUB STRIKING SURFACE

Description This application is a continuation-in-part of U.S. Patent Application Serial No.

08/568,391, filed on December 6, 1995, and which is hereby incoφorated herein by reference.

Background Art In many sports, including golf, it is critical for the ball to be driven over a relatively long distance, while being accurately directed along an intended path. In the past, numerous technologies have been employed to improve the design and construction of golf clubs so as to enhance the flight performance of a golf ball. In particular, it has been recognized that by providing the striking surface of a golf club with certain physical characteristics, the flight performance of the golf ball may be increased. For instance, the inclusion of a high frictional striking surface on the head of a golf club can allow a player to attain a higher degree of control over the ball, while simultaneously decreasing the tendency of the golf ball to deviate from an intended course.

Currently, there are numerous designs directed toward providing a high frictional striking surface on a golf club. For example, horizontal grooves oriented along the striking surface have been found to effectively increase the friction between the striking surface and the golf ball. Because of their effectiveness in increasing friction between the striking surface and the ball, it is now common for a golf club to have a series of horizontally oriented grooves on striking surface. Other designs have been employed to further increase the friction between the striking surface and the golf ball. One example of such a design is disclosed in U.S. Patent No. 4,768,787, issued to Shira for an invention entitled "Golf Club Including High Friction Striking Face". Shira discloses a face insert, i.e., the striking surface of a club head, having a striking surface formed from a mixture of hard abrasive particles intermixed with a soft binding agent. The abrasive particles, within the striking surface, provide a high-frictional surface which aids in the production of backspin on the golf ball when the ball is struck. Unfortunately, the attempt to increase friction between the striking surface and the golf ball has often come at the expense of distance. In particular, the use of abrasive particles to increase the amount of backspin on the ball can cause the amount of friction between the surface of the spinning ball and the layer of air moving over the ball to increase. The increase in friction on the surface of a spinning ball can subsequently act to noticeably decrease the distance over which the ball may travel. Furthermore, the use of a soft binding agent, such as that by Shira, has been found to have several disadvantages. In particular, there is a tendency for the soft binding agent to elastically deform at the point of contact between the club head and the ball. The elastic deformation tends to absorb some of the kinetic energy associated with the moving club head and, as a result, reduces the amount of kinetic energy imparted to the ball. When the amount of kinetic energy imparted to the ball is reduced, the distance over which the golf ball may be driven can also significantly reduce.

The elastic deformation of the striking surface at the point of contact between the golf club and the golf ball may also cause the underlying material in the club head to be plastically deformed and become damaged. In addition, a soft binding agent may reduce the durability of the club head, especially when the club is consistently played under adverse conditions. Under normal playing conditions, the tendency of a soft binding agent to wear is noticeably detectable after only a few rounds. If the golf club is, instead, subject to adverse playing conditions, such as sandy soils or rain, the tendency of the striking surface to wear may be accelerated.

Accordingly, it is desirable to provide a golf club having a hard striking surface that not only resists wear and elastic deformation, but has a the ability control the amount of spin imparted to the ball so as to enhance the flight performance of the golf ball, while not diminishing the ability of the player to control and direct the ball along a flight path.

Summary of the Invention The present invention is a method for enhancing frictional engagement on a striking surface of a golf club. Such a method allows the club to better direct a golf ball along a path without compromising the distance over which the ball may travel. The method may be accomplished by applying, to a striking surface of the golf club, an extremely hard, homogenous and essentially wear-resistant coating having a high amount of surface porosity and a low amount of abrasiveness. The homogenous and highly porous coating is light, and despite its low abrasiveness, has a high coefficient of friction. This is because the hardness of the homogenous and porous coating allows the golf ball to conform to the surface of the coating, including the pores on the surface, so as to increase the surface area in contact between the striking surface and the ball. The striking surface onto which the coating of the present invention may be applied is preferably made from a metal, such as stainless steel, and includes a series of substantially parallel grooves oriented horizontally across the face of the striking surface. The striking surface may also be fabricated from titanium, or other suitable metal so long as the metal is of sufficient hardness to strike and/or drive the ball without being elastically deformed.

To apply the coating to the striking surface, the striking surface is first isolated from the other portions of the club not involved in striking the ball. In the event the head of the golf club is a one piece design, a high-temperature masking system, for example, a silica glass tape or template, is used to cover the portions of the club head adjacent the striking surface to protect those portions from being coated. In the event the head of the golf club is a multi-piece design, wherein the striking surface is removable, the striking surface is first isolated by removing it from the club head. Once the striking surface has been isolated, it is subject to a texturing procedure aimed at establishing a textured striking surface to insure a proper bonding of the hard coating to the striking surface of the club head. Numerous techniques may be utilized to establish a textured striking surface. For the purposes of the present invention, however, it has been found that using a grit or sand-blasting process, or other blasting processes employing a hard and coarse material, is particularly effective. Once the striking surface has been subject to the texturing procedure, the resulting textured surface preferably has roughness ranging from approximately one hundred and forty (140) to one hundred and sixty (160) microinches AA. It should be appreciated that roughness, in the present context, is measured according to the American National Standard for roughness measurement, as set forth in Thermal Spraying, Practice, Theory, and Application: Surface Preparation, Ch. 3, p. 17, (1985). Roughness, as a measurement, consists of the finer irregularities in the surface texture, usually including those irregularities which result from the inherent action of the production process. Measurements of roughness, therefore, are expressed as an Arithmetical Average (AA) deviation from the mean surface in microinches.

After texturing, an optional ceramic priming layer, such as molybdenum nickel aluminum, nickel alumina, or any other suitable bond-coat material, may be applied to the textured surface to ensure proper bonding of a subsequent coating compound onto the striking surface The priming layer may also act to prevent corrosion of the striking surface when the club is subject to constant adverse playing conditions The application of the priming layer to the textured striking surface may be performed by methods well known in the art, for instance, plasma spray or flame spray application. In a preferred embodiment of the invention, the application of the priming layer should be controlled to produce a relatively uniform thin layer having a thickness range of from approximately 0 00005 inch to 0.0002 inch

A homogenous coating is next applied to the striking surface by a flame spray method or by a plasma spray method. The coating may be selected from the group consisting of.

Chromium Carbide, Tungsten Carbide-Cobalt Alloy, Tungsten Carbide-Cobalt Aggregate, Tungsten Carbide-Cobalt Composite, Chromium Carbide-Nickel Chromium Alloy,

Chromium Carbide-Nickel Chromium Composite, and Tungsten Carbide self fusing Alternatively, the striking surface may be sprayed with a ceramic compound selected from the group consisting of Gray Alumina,

Titanium Dioxide, White Alumina, Chromium Oxide, Alumina-Titama Composite, Zirconia,

Z onium Oxide Composite, Magnesium Zirconate, Magnesia-Alumina Spinel, and Yttπa stabilized Zirconia In the preferred embodiment, the coating is a ceramic compound having a mixture of alumina-titania composite, with aluminum oxide comprising approximately 60% by weight of the mixture, and titanium dioxide comprising approximately 40% by weight ot the mixture During the spray application, the particular compound selected is heated to a temperature which assures transformation of the compound to a molten state For example, a compound mixture of aluminum oxide and titanium dioxide is heated to a molten temperature of approximately 4000° Fahrenheit. The molten compound, after having been sprayed onto the striking surface, becomes fused to the surface, as well as to other molecules within the compound, to form a homogenous and dense coating with a porous coating surface The resulting coating preferably has a Rockwell hardness of approximately 50RC to 70RC Hardness, in the present context, is measured by the Rockwell "C" hardness scale (RC), as referenced in Thermal Spraying, Practice, Theory, and Application Surface Preparation, Ch 2, p 7, (1985) The resulting coating also preferably has a thickness ranging from approximately 0.002 inch to approximately 0 005 inch, and a surface roughness ranging from about 100 microinches A A to about 140 microinches AA The homogenous and porous coating obtained by the present method provides a coating that is low in abrasiveness In addition, because the coating allows a golf ball to conform to the surface of the coating, including the pores, so as to increase the surface area in contact between the striking surface and the ball, the coating obtained by the present method provides a striking surface with a surprisingly high coefficient of friction. The combination of a higher coefficient of friction, which tends to improve the frictional engagement between the striking surface and the golf ball so as to better control the ball, and a low abrasive surface, which tends to control the amount of backspin and lateral spin imparted to the ball, produces an unexpectedly improved performance by the golf ball, including the distance over which the ball travels, and the trajectory which the ball takes Brief Description of the Drawings Other novel features and advantages of the present invention will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which:

Fig. 1 is a perspective view of a golf club head;

Fig. 2 is a perspective view of a golf club head with a removable striking surface; Fig. 3 is a schematic diagram of a method in accordance with one embodiment of the present invention; Fig. 4a is a partial cross-sectional view of the club head of Fig. 1 or Fig. 2 showing a grooved portion on the striking surface before treatment by the method of the present invention;

Fig. 4b is the grooved portion on the striking surface of Fig. 4a after the texturing step of the present invention; Fig. 4c is the grooved portion on the striking surface of Fig. 4b after the priming step of the present invention;

Fig. 4d is the grooved portion on the striking surface of Fig. 4c after the coating step of the present invention;

Fig. 5 is a plan view of a flame sprayer as used by the present invention; Fig. 6 is a plan view of a plasma sprayer as used by the present invention;

Fig. 7 shows a performance comparison between a golf club coated with the method of the present invention, and a similar golf club that has not been coated;

Fig. 8 shows a backspin comparison of several golf clubs coated with the method of the present invention against similar non-coated clubs having similar number designations;

Figs 9a-b show another performance comparison between a conventional golf club and the same golf club that has been coated by the method of the present invention; and Figs. lOa-c show the performance results of clubs coated with the process of the present invention against clubs having similar number designations and clubs having different number designations. Detailed Description of the Preferred Embodiments Referring now to the drawings, Fig 1 illustrates a golf club head 10 having a body 12 and a striking surface 14 In the embodiment of Fig. 1, the club head 10, the striking surface 14, and body 12 are fabricated as a single piece club head The striking surface 14 is formed from a hard metallic material, for instance, stainless steel, and may include a series of substantially parallel, horizontally oriented grooves 16 Grooves 16 are not necessary when practicing the method of the present invention, but may, nevertheless, be provided on the striking surface 14 to enhance the coefficient of friction between the striking surface 14 and a golf ball (not shown) when the striking surface 14 engages the golf ball By enhancing the coefficient of friction, a greater degree of control over the golf ball may be provided when the ball is struck by the striking surface 14 Although the striking surlace 14 is preferably stainless steel, it may also be formed from other suitable metal, for example, titanium, so long as the metal is sufficiently hard and does not elastically deform when it is used to strike and drive a golf ball In Fig. 2, an alternative club head 10' is shown. Club head 10' includes a body 12' and a striking surface 14' formed with a series of grooves 16' similar to the grooves 16 shown in Fig. 1 In many respects, club head 10' is the same or similar to club head 10 of Fig 1 However, club head 10', rather than being formed as a single piece, is formed as a multi-piece assembly wherein the striking surface 14' is independent of the body 12', that is, the striking surface 14' is removable from the body 12'. In the embodiment of Fig. 2, the striking surface 14' may be mounted to the body 12' by methods well known in the art which includes, but are not limited to, screw mounting, riveting, adhesive bonding and welding. The striking surface 14' may be formed from stainless steel, titanium, or other suitable metal for striking and driving a golf ball. The method of the present invention may be best appreciated by reference to Fig

3, wherein the method is shown schematically, and to Figs. 4a through 4d, where a portion 18 about groove 16 on the striking surface 14 is shown in successive phases, with each phase corresponding to a step of the present invention For convenience, the portion 18 about groove 16 will be referred to hereinafter as grooved portion 18, and reference to groove 16 is made with the understanding that such reference is similarly applicable to groove 16' on the striking surface 14 of Fig. 2 The method of the present invention is advantageously applicable to either a club head 10 having a one piece design, as shown in Fig 1 , or a club head 10' having a multi- piece design, as shown in Fig. 2. To prepare the club head for coating, with reference now to Fig. 3, the striking surface 14 or 14' must first be isolated from the portions of the club head not involved in striking the golf ball, as generally shown in box 22 The isolated striking surface 14 or 14', made from a stainless steel material 20, preferably includes a groove 16 and grooved portion 18 shown in detail in Fig. 4a. In the event the club head is a one piece design, the portions on the club head 10 adjacent to the striking surface 14 are isolated by first covering those portions of the club head 10 which do not require an application of the coating with a high temperature masking material. Generally, any masking technology which provides the required protection and resistance to high- temperatures may be utilized For the purposes of the present invention, the use of silica glass tape has been found to be particularly effective The use of a high temperature masking material may, however, be eliminated if protection of the non-striking surface is not desirable and application of a coating over the entire club head 10 is acceptable. In the event the club head is a multi-piece design, the striking surface 14' may be isolated from the club head 10' by removing the striking surface from the body 12'.

Once the striking surface has been isolated from the other portions of the club head, a texturing step, generally indicated by box 24 of Fig 3, may be performed on the striking surface. In the texturing step, each of the striking surface 14, the groove 16 and the grooved portion 18, is imparted with an abrasive and roughened surface quality, as can be seen in Fig. 4b Texturing may be performed by a number of different methods or techniques well known in the art. One such technique involves the application of a high pressure spray of a hard and abrasive material directed at the striking surface 14. High pressure spraying in the nature of sand, or bead blasting has been found to be particularly effective when attempting to textunze a metal surface such as a golf club striking surface In accordance with one embodiment of the invention, the resulting textured surface, including the groove 16 and grooved portion 18, preferably has a roughness in the range of from approximately 140 microinches AA to approximately 160 microinches AA, with a preferred roughness being approximately 150 microinches AA. The texturing step, indicated as box 24 in Fig. 3, may be followed by an optional priming step generally designated by box 26. The priming step of box 26 may be better appreciated by brief reference to Fig. 4c, where it may be seen that a priming layer 30 of a ceramic material has been applied over the groove 16 and grooved portion 18. The ceramic priming layer 30, which has been applied over the groove 16 and grooved portion 18, may be needed so as to ensure proper bonding of a subsequent homogenous coating layer of a ceramic compound (see box 28) to the striking surface 14. The ceramic priming layer 30 is especially helpful when the subsequent homogenous coating layer, despite texturization of the striking surface, cannot adhere tightly to the striking surface 14. The ceramic priming layer 30 may also be applied to inhibit corrosion of the striking surface 14, particularly when the club head 10 is subject to constant adverse playing conditions, such a sandy soils or rain. To apply the priming layer 30 shown in Fig. 4c, in one embodiment of the invention, the textured striking surface 14 is preferably flame sprayed or plasma sprayed (a discussion of which is provided hereinafter in detail) with a molten ceramic compound, such as molybdenum nickel aluminum (similar to Metco material number 447, which is manufactured by Metco, Inc. of Long Island, New York, or equivalent), nickel alumina (similar to Metco material number 450 or equivalent), or any other suitable bond-coat material. The flame spray or plasma spray is performed under pressure so that a thin and uniform priming layer 30 may cover substantially the entire striking surface 14, including the groove 16 and grooved portion 18. As a thin uniform priming layer 30 is desirable, the spray application of the molten ceramic material is preferably controlled to limit the thickness of priming layer 30 to a range of from about 0.00005 inch to about 0.0002 inch. In the preferred embodiment of the invention, the priming layer 30 has a thickness of about 0.0001 inch. For the purposes of the present invention, it should be appreciated that since some ceramic compounds, when used as a coating, are capable of bonding tightly to a striking surface having the indicated preferred roughness without the need for a priming layer, the priming step of box 26 may not be necessary in ali cases.

Still referring to Fig. 3, it may be seen that the priming step of box 26 is followed by a coating step generally designated by box 28. Box 28 represents a spray application of a compound in a molten state to the striking surface 14. In accordance with one embodiment of the present invention, the compound may be selected from the group consisting of:

Chromium Carbide, Tungsten Carbide-Cobalt Alloy, Tungsten Carbide-Cobalt Aggregate,

Tungsten Carbide-Cobalt Composite, Chromium Carbide-Nickel Chromium Alloy, Chromium Carbide-Nickel Chromium Composite, and Tungsten Carbide self fusing. In the preferred embodiment of the invention, the striking surface 14 is sprayed with a ceramic compound selected from the group consisting of: Gray Alumina, Titanium Dioxide, White Alumina, Chromium Oxide,

Alumina-Titania Composite, Zirconia,

Zirconium oxide composite, Magnesium Zirconate, Magnesia-Alumina Spinel, and

Yttria stabilized Zirconia. In the present invention, the preferred ceramic compound includes a mixture of alumina-titania composite, wherein aluminum oxide comprises approximately 60% by weight of the mixture and titanium dioxide comprises approximately 40% by weight of the mixture.

To apply the selected ceramic compound, in one embodiment of the invention, the ceramic compound is initially heated to a temperature which assures transformation of the compound to a molten state. For example, a mixture of aluminum oxide and titanium dioxide is heated to a temperature of approximately 4000° Fahrenheit. The molten ceramic mixture is then spray onto the striking surface 14 at a velocity of approximately 2000 feet per second (fps). One application method employed by the present invention is generally known as flame spraying, and may be better appreciated by reference to Fig 5, where a flame sprayer 32 (similar to a 3M, 7M or 9M Metco sprayer, or a Metco HVOS System) is shown As shown in Fig 5, the flame sprayer 32 includes a body 34, and a channel 36, extending through the body 34 and terminating in an orifice 38 An ignitor 40 is attached to body 34 and is positioned adjacent to the orifice 38 A volatile gas supply 42 is provided for injecting a stream of volatile gas, under pressure, into channel 36 A material supply 44 is connected to the flame sprayer 32 and is used to introduce the selected ceramic compound into the channel 36 Functionally, the volatile gas and the ceramic compound are intermixed within the channel 36 and the resulting product is emitted through orifice 38 Once emitted through the orifice 38, the volatile gas is ignited by ignitor 40 heating the ceramic compound to its molten state The pressure provided by the gas then projects the now molten ceramic compound toward the striking area 14 at a velocity of about 2000 fps

Fig 6 shows a plasma sprayer 46 (similar to a 3M, 7M or 9M Metco sprayer, or a Metco HVOS System), which may be used as an alternative to the flame sprayer 32 of Fig 5 As shown in Fig 6, plasma sprayer 46 includes a body 48, a channel 50 which extends along the body 48, and ends at an orifice 52 A first electrode 54 and a second electrode 56 are positioned within the channel 50 An inert gas supply 58 is provided to inject a stream of inert gas, under pressure, into channel 50 A material supply 60 is attached to the plasma sprayer 46 and is used to introduce the selected ceramic compound into the channel 50 Functionally, the inert gas and the ceramic compound are intermixed within channel 50, and after which an electric current passing between first electrode 54 and second electrode 56 is provided to convert the inert gas into a plasma The plasma and ceramic compound mixture are then emitted through the orifice 52 At the orifice 52, the plasma naturally reverts back to its original gaseous state thereby releasing thermal energy which is harness to heat the ceramic compound to its molten state The pressure provided by the gas then projects the now molten ceramic compound toward the striking area 14 at a velocity of about 2000 fps

As described above, either the flame sprayer 32 of Fig 5 or the plasma sprayer 46 of Fig 6, may be used to spray the molten ceramic compound onto the striking surface 14 On impact with the striking surface 14, the molten compound fuses to the surface 14. and to other molecules within the compound, so as to form a fused and homogenous ceramic layer 62 having a porous surface, as shown in Fig 4d Moreover, the layer 62 acts to smooth out the relative sharp edges along groove 16 on the striking surface 14 In accordance with one embodiment of the present invention, the spray application of the molten ceramic compound is controlled so as to provide a layer 62 that has a thickness in the range of from about 0 002 inch to 0 004 inch A layer 62 with a thickness of 0 003 inch is presently preferred The present invention recognizes that the hardness and roughness of layer 62 may be adjusted by altering and/or modifying the selected compound, including the weight percentage of the ceramic mixture in the compound However, the selected compound should provide a layer 62 which has a Rockwell hardness in the range of from approximately 50RC to approximately 70RC, and a roughness measurement ranging from about 100 microinches A A to about 140 microinches AA In accordance with the preferred embodiment of the invention, the layer 62 has a Rockwell hardness of 63RC, and a roughness of 120 microinches AA The homogenous and porous layer 62, when applied to the striking surface 14 by the process of the current invention, provides the striking surface with a hard coating which is essentially wear-resistant Typically, with a conventional golr club, wear on the striking surface is detectable after only a few rounds of play Similarly, a golf club which has incorporated a soft binding agent and hard particles onto the striking surface, so as to increase friction with the ball, can show signs of wear only after a few rounds The homogenous and porous layer 62, on the other hand, provides a striking surface with enhanced wear-resistance, so that the surface may not show any signs of wear after extended use

The homogenous and porous layer 62 also provides the striking surface with a high coefficient of friction. The high coefficient of friction is attained by allowing a golf ball to conform to the surface of the hard layer 62, including the pores on the surface of the layer 62, so as to increase the surface area in contact between the striking surface 14 and the ball By increasing the surface area between the striking surface and the ball, the frictional engagement with the ball may improve In addition, the homogenous and porous layer 62 has a low abrasiveness quality This low abrasiveness quality, along with the smoother edges along groove 16, allows the amount of spin imparted to the ball, and thus the amount of friction between the surface of the spinning ball and the layer of air moving thereover, to be controlled. For instance, the low abrasiveness and smoother edges can provide less spin to the golf ball when the ball is struck by a driver, a wood, or a long iron, and more spin to the ball when the ball is struck by a short iron, such as a 9 iron or a pitching wedge. In the present invention, the combination of high coefficient of friction and low abrasiveness of the layer 62 produces an unexpected improved performance by the golf ball, including the distance over which the ball travels.

In tests comparing the performance between conventional golf clubs and golf clubs which have been coated with a homogenous and porous layer 62 by the method of the present invention, the driving distances of those clubs having the layer 62 are noticeably better than those of the conventional clubs. Evidence of improved performance can be clearly demonstrated in one comparison test, the results of which are shown in Fig. 7. The test measures the distance over which a golf ball is driven, and the amount of backspin imparted to the ball, by two golf clubs of similar specifications, one of which, however, is coated with the homogenous and porous layer 62 by the method of the present invention. In Fig. 7, results from the comparison test indicate that with a club head speed of approximately 94.2 miles per hour (mph), the club coated with the homogenous and porous layer 62 (designated as WLTH/BLKICE) is able to drive a Titleist DT90 3 PC golf ball over a longer distance, 217.2 yards, and with less spin, 2960 revolutions per minute (φm), than the club without the coating (designated as NO/BLKICE). Indeed the lower φ number on the ball hit by the coated club helps to cut down on the amount of friction acting on the surface of the spinning ball, which in turn allows the ball to travel over a longer distance.

Evidence of a lower spin rate imparted to a golf ball by clubs coated with the homogenous and porous layer 62 may further be seen in Fig. 8. Fig 8, compares the spin rate imparted to a golf ball by a conventional Dynatour club and a conventional 3 iron against that by a similar Dynatour club and 3 iron that have been coated with the homogenous and porous layer 62. The coated clubs, in Fig. 8, are each designated with the prefix Ceramic. As illustrated, at a substantially similar club speed, the amount of backspin produced by the coated club is generally lower than the amount of backspin produced by the conventional club. A higher amount of backspin, however, may be desirable in some instances, for example, when using a club with a high number designation A club with a high number designation, for instance, a 9 iron or a pitching wedge, are typically designed with a more angled club head, so as to provide more loft and backspin to the ball so that a higher degree of control and accuracy may be achieved, while simultaneously decreasing the tendency of the ball to roll after contact with the green In Fig 8, the comparison test shows that when a club with a high number designation, such as a 9 iron, is coated with the homogenous and porous layer 62, the club tends to impart more backspin to a golf ball than a similar conventional club The ability of the layer 62 to provide additional backspin allows these clubs to substantially decrease the tendency of the ball to roll after contact with the green, thereby allowing the player to have more control over the ball

Distance performance, in some cases, may be better despite not squarely hitting a golf ball in the center of the club head coated by the method of the present invention Evidence of such improved performance can be seen in a comparison test which measures the distance over which a golf ball is driven by a standard 10° Callaway Big Bertha War Bird golf club with an HM-35 F shaft, and the exact same Callaway golf club provided with a homogenous and porous layer 62 by the process of the present invention The comparison test measures the distance traveled by the golf ball when the ball is hit with a club speed of approximately 90 miles per hour, at the center of the club head, the toe of the club head, and the heel of the club head As can be seen under the "Carry" column in each of Fig 9a, showing results from the standard Callaway golf club, and Fig 9b, showing results of the Callaway golf club coated with a homogenous and porous layer 62, the distance over which the coated Callaway club is able to drive a golf ball is noticeably further than the distance driven by the standard Callaway club In some instances, as shown in Fig 9b, hitting a ball with a coated club near the toe of the club can produce a result which is more favorable, approximately 193 yards, than when the ball is squarely hit in the center of the non-coated club head, approximately 191 yards.

Figs 10a through 10c compare the performance results of clubs having a certain number designation and which have been coated with the homogenous and porous layer 62 by the method of the present invention (indicated as Black Ice), against similar conventional clubs having correspondingly similar number designations, as well as conventional clubs having different number designations. As expected, in Fig. 8a, when compared against conventional clubs with correspondingly similar number designations, the clubs coated by the method of the present invention are able to drive a golf ball over a further distance the conventional clubs. More impressively, however, as shown in Fig. 8b, when a Black Ice Tour Model #3 wood (manufactured by Black Ice Golf Company, Inc. of San Marcos, California) is coated by the method of the present invention, the distance over which a golf ball is driven, when hit with a club speed of about 90 miles per hour, is comparable to that of well known drivers. It should be appreciated that under normal circumstances, a 3 wood provides relatively more loft to a golf ball than a driver, and as a result, cannot drive a golf ball as far as a driver.

While the particular method for applying a coating to a golf club striking surface has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification. This application is intended to cover any variations, uses, or adaptations of the invention and including such departures from the present disclosures as come within known or customary practice in the art to which the invention pertains.

Claims

What is claimed is

1 A method for providing a striking surface of a golf club with enhanced frictional engagement with a golf ball, the method comprising. texturing the striking surface of the club, applying a substantially homogenous layer of a ceramic compound onto the striking surface, the layer providing a high coefficient of friction for enhanced frictional engagement with the golf ball

2 A method as set forth in claim 1 wherein the step of texturing includes the step of spraying the striking surface with a hard, abrasive material so as to increase roughness on the striking surface.

3 A method as set forth in claim 1 wherein the step of texturing provides the striking surface with a roughness ranging from about 140 microinches AA to about 160 microinches AA

4 A method as set forth in claim 3 wherein the step of texturing provides the striking surface with a roughness of about 150 microinches AA

5 A method as set forth in claim 1 further including the step of depositing a priming layer of ceramic material onto the textured striking surface prior to the step of applying so as to ensure proper bonding of a subsequent layer onto the striking surface

6 A method as set forth in claim 5 wherein in the step of depositing, the ceramic material is selected from the group consisting of molybdenum nickel aluminum, and nickel alumina

7 A method as set forth in claim 5 wherein the priming layer is deposited onto the striking surface with a thickness measuring from about 0 00005 inch to about 0.0001 inch

8 A method as set forth in claim 7 wherein the priming layer is deposited onto the striking surface with a thickness of about 0 0001 inch

9 A method as set forth in claim 1 wherein the ceramic compound is selected from the group consisting of Chromium Carbide, Tungsten Carbide-Cobalt Alloy,

Tungsten Carbide Cobalt Aggregate, Tungsten Carbide-Cobalt Composite, Chromium Carbide-Nickel Chromium Alloy, Chromium Carbide-Nickel Chromium Composite, Tungsten Carbide self fusing, Gray Alumina, Titanium Dioxide, White Alumina, Chromium Oxide, Alumina-Titania Composite, Zirconia, Zirconium Oxide Composite, Magnesium Zirconate, Magnesia-Alumina Spinal, and Yttπa stabilized Zirconia

10 A method as set forth in claim 9 wherein the ceramic compound is an alumina-titania composite.

1 1 A method as set forth in claim 9 wherein the step of applying includes the steps of heating the ceramic compound to a molten temperature; and spraying a layer of the ceramic compound onto the striking surface

12 A method as set forth in claim 1 1 wherein the step of spraying includes plasma spraying.

13 A method as set forth in claim 1 1 wherein the step of spraying includes flame spraying.

14 A method as set forth in claim 1 wherein the homogenous layer of ceramic compound has a surface porosity.

15. A method for providing a striking surface of a golf club with enhanced frictional engagement with a golf ball, the method comprising- spraymg the striking surface with a non-adhesive abrasive material so as to increase roughness on the striking surface, applying a priming layer of ceramic mateπal onto the striking surface to ensure proper bonding of a subsequent layer onto the striking surface, heating a ceramic compound having a high coefficient of friction to a molten state, and depositing a homogenous layer of the molten ceramic compound onto the priming layer

16 A method as set forth in claim 15 wherein the step of spraying provides the striking surface with a roughness ranging from about 140 microinches A A to about 160 microinches AA

17 A method as set forth in claim 16 wherein the step of spraying provides the striking surface with a roughness of about 150 microinches AA

18 A method as set forth in claim 15 wherein in the step of applying the priming layer, the ceramic material is selected from the group consisting of molybdenum nickel aluminum, and nickel alumina.

19. A method as set forth in claim 15 wherein the step of applying provides the priming layer with a thickness measuπng from about 0 00005 inch to about 0 0002 inch

20. A method as set forth in claim 19 wherein the step of applying provides the priming layer with a thickness of about 0.0001 inch

21 A method as set forth in claim 15 wherein in the ceramic compound in the step of heating is selected from the group consisting of Chromium Carbide, Tungsten Carbide-Cobalt Alloy, Tungsten Carbide Cobalt Aggregate, Tungsten Carbide-Cobalt Composite, Chromium Carbide-Nickel Chromium Alloy, Chromium Carbide-Nickel Chromium Composite, Tungsten Carbide self fusing. Gray Alumina, Titanium Dioxide, White Alumina, Chromium Oxide, Alumina-Titania Composite, Zirconia, Zirconium Oxide Composite, Magnesium Zirconate, Magnesia-Alumina Spinal, and Yttria stabilized Zirconia

22 A method as set forth in claim 21 wherein the ceramic compound is a alumina-titania composite

23 A method as set forth m claim 15 wherein the step of depositing includes plasma spraying

24 A method as set forth in claim 15 wherein the step of depositing includes flame spraying

25 A method as set forth in claim 15 wherein the homogenous layer of ceramic compound has a surface porosity

26 A method as set forth in claim 15 further including the step of cooling the deposited molten ceramic compound into a hard coating once the molten ceramic compound has been deposited onto the layer of aluminum oxide

27 A method as set forth in claim 26 wherein the hard coating has a hardness ranging from about 50RC to about 70RC

28 A method as set forth in claim 27 wherein the hard coating has a hardness of about 63RC

29 A method as set forth in claim 26 wherein the hard coating has a thickness ranging from about 0002 inch to about 0 005 inch

30. A method as set forth in claim 29 wherein the hard coating has a thickness of about 0 004 inch