JPH09122281A - Golf club with elastomer vibration damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf club which can damp vibration at impact. SOLUTION: A hollow wood type golf club 50 has a thin layer 54 of an elastomeric damping material to cover an inside surface area existing inside of a hollow cavity of a head shell 52 by opposing a ball hitting surface. This layer 54 damps vibration, and improves play of the club. In order to inexpensively and easily make a head having this layer 54, a necessary quantity of unhardened elastomer is dispersed in the cavity in liquid, and the head having an inside surface opposed to the ball hitting surface is horizontally maintained, and the liquid is pooled on this inside surface area, and the head is left as it is until the elastomer is hardened, and the elastomer is hardened. A head of an iron and a head of a putter of golf have a vibration damper composed of a tin layer of an elastomer material fixed to a base cavity surface of a cavity to line a ball hitting surface. A method of making an iron and a putter is also explained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to golf clubs, and to vibration dampening golf clubs and methods for making such clubs.

[0002]

BACKGROUND OF THE INVENTION Hollow "wood" type golf club heads are widely used today and are usually made of a thin hollow shell to which the club shaft is mounted. These types of clubs have replaced most of the original wood clubs actually made from persimmon trees, and these types of clubs are used as driver and fairway woods. The above shell is usually made of metal such as stainless steel, aluminum or titanium alloy, but graphite,
It may also be made of other materials such as ceramics, polycarbons and plastics.

[0003]

By the way, a problem related to such a golf club is vibration generated from a hit with a ball. There is a hollow wood type club in which a hollow shell is filled with urethane foam, and in this case, some vibration damping can be performed. However, after a long period of time and as a result of playing in the club,
The foam may deteriorate and peel off from the inside surface of the head, causing annoying muffled sounds. Irons and putters are also subject to similar vibrations.

[0004]

According to the present invention, a club shaft and a "wood" type club head are provided.
A vibration damped hollow "wood" type golf club is provided. The head has a hollow shell defining a ball striking surface and a head body, the shell having an inner surface defining a hollow cavity. The inner surface includes a surface area facing the ball striking surface and having an area at least as large as the ball striking surface. A vibration damper composed of a thin layer of elastomeric material is secured to the surface area and covers substantially the entire surface area. The thin layer is for damping the vibration generated by the hitting of the ball hitting surface with the golf ball. The present invention also provides a vibration damped "iron" type golf club having a club shaft and an "iron" type club head. The head has a head body that defines a ball striking surface and a hollow cavity that lines the ball striking surface, the cavity being partially defined by the base surface of the cavity.
The club further includes a vibration damper secured to the base surface of the cavity and comprising a thin layer of elastomeric material covering substantially the entire base surface of the cavity, the thin layer comprising a golf ball on the ball striking surface. It is for attenuating the vibration caused by the impact with. The present invention further provides a vibration dampened golf putter club having a club shaft and a putter club head. The head has a putter head body that defines a ball striking surface and a hollow cavity that lines the ball striking surface. The cavity is partially defined by the base surface of the cavity. The vibration damper consists of a layer of elastomeric material that covers substantially the entire base surface of the cavity, the layer being intended to damp vibrations caused by striking the ball striking surface against the golf ball. According to the present invention, there is further provided a method for making these golf clubs.

[0005]

Embodiments of the present invention will be described below in detail. FIG. 1 is an explanatory diagram of a hollow wood type golf club head 50. Club head 50
Is made of a thin hollow shell. The shell is usually metal, but can also be constructed from ceramic or other materials. The shell includes an inner surface 70 (FIG. 3) that defines the cavity 56 thereof. FIGS. 10 to 12
As shown in Figure 3, the entire inner surface of shell 52 is covered with a thin layer 54 of polyurethane elastomer according to the present invention. This layer is intended to completely cover the inner shell surface and also provide great vibration damping. This layer alters the sound of the club head striking the ball, reducing the frequency of impact. As a result, the feel of the club is improved and the vibrational energy transmitted to the player is reduced.

A typical preferred material for layer 54 is available from BJ-B-enterprise Inco-Corporation of Nautilus Drive 13912, Garden Grove, CA 92643, Calif.
F-70 A / B 70 SHORE-A polyurethane elastomer. This material is a mixture of liquid parts A and B, part A being a polyurethane resin and part B being a polyurethane hardener. This typical material and its properties are described in "F-70A / B 70 Shore A-
Polyurethane elastomer ratio: 100/10
It is described in the product data table entitled "0".

2-9 illustrate the steps of an exemplary method for making the golf club head 50 of FIG. FIG. 2 is a simplified schematic diagram of a typical system 100 for injecting liquid-state vibration damping material into a hollow wood-type club head 50. Polyurethane elastomer has two liquid parts A and B
Which are mixed together when the elastomer is used and cured. Therefore, the parts A and B are held in the respective containers 104 and 106 in a liquid state. The system comprises a mixer 102 in which the vessels described above are connected by tubes 108 and 110 to supply parts A and B. In this exemplary embodiment, the mixer is a mechanical device for mixing two liquid parts, but these parts may be mixed statically. The mixer includes an impeller (not shown) that supplies the mixed product to the outlet tube 112.

FIG. 3 is a cross-sectional view of a wood-type club head 50 illustrating the process of injecting a liquid vibration damping material into the golf club head using the system of FIG. The tip 114 of the outlet tube 112 is inserted into the hosel opening 58 of the club head that ultimately supports the end of the club shaft. The mixed product of parts A and B is in a thin liquid state and is expelled from tip 114 by pressurization. The required amount of liquid, typically on the order of 12 grams for one exemplary club head, is expelled into the hollow cavity 56 of the club head.

In the next step of the process, as illustrated in FIG. 4, the club head 50 with the required amount of liquid material therein is manually covered with this liquid over the entire inner surface 70 of the club shell. Be inclined to.

In the next step, as shown in FIG. 5A, compressed air is sent through the hosel opening to the inside of the shell,
Turbulence is created within the cavity 56 to expel excess liquid material. This can be done by using the configuration shown in FIG. 5B in a typical embodiment. That is, holding the club head upside down, about 25 psi of compressed air is expelled from the tube 120 and nozzle 122 into the cavity 56. The shroud 124 collects excess liquid dripping from the hosel opening.

FIG. 6 illustrates the next (optional) step in which the club head 50 is weighed with the weigh scale 130 after removing the excess amount of liquid as shown in FIG. 5B. P to control the allowable range of club head weight
There is a GA rule, and each type of club head is usually made by the manufacturer to have a predetermined weight or mass. The head shell 52 is designed and constructed to have a nominal weight that is a large percentage of the final desired club weight, without the slight weight added by vibration damping material. The purpose of the metering process shown in FIG. 6 is to determine the weight of the head 50 after the liquid elastomer has been used and before the material has cured. Typically, the head is designed slightly lighter than its nominal final weight after the liquid elastomer is used. During the weighing process, it is determined how much weight can be added to the club head 50 to bring it to a nominal final weight. This additional weight is preferably provided by a separate injection of liquid elastomer through the hosel opening 58 and into the hollow cavity 56 while the head is on the weigh scale 130 as shown in FIG. This allows for exactly the desired final weight at this stage of the process.

FIG. 8 illustrates the steps for tilting and positioning the club head so that the excess liquid added as shown in FIG. 7 will flow to the desired location within the hollow club head. . This is done to bring the club head to the desired weight. For example, manufacturers typically want to add weight to the back of the head away from the striking surface 60. This secures a rod or dowel 140 below the striking face 60, and the head rear face 6
4 by lifting this part of the club head. Other rods or dowels 142
May be positioned after the club head to prevent the head from sliding or rolling off the dowel 140. Both dowels 140 and 142 were supported on a flat surface 144 in this example. The tilted position of the club head results in excess liquid elastomeric material flowing to the back surface 64 and pooling, forming thick areas of elastomer.
This allows the mass of the thicker region 62 to make the back of the club head heavier. Of course, other weighting configurations can be achieved by tilting the head so that the club's toe or heel is at its lowest point and pooling excess liquid elastomer in these toes or heels.

Next, FIG. 9 shows a step of oven curing the liquid vibration damping material at a high temperature while the club head 50 is inclined and positioned. Here, the flat surface 144
Is a plywood or sheet of metal that can be easily removed from the curing oven 150 and the head 50 can be heated for a desired time interval to cure the polyurethane elastomer material to a solid state. For the exemplary materials described above, the head is fired for 2 hours at a temperature in the range of 160 ° F to 200 ° F. Once the material has hardened, the head 50 is removed from the oven and allowed to cool, and the shaft is conventionally secured to the hosel opening 58 to complete the manufacturing process.

The thickness of the layer of elastomer is preferably
5 to 10 mils around the inside surface of the cavity
However, the thickness in the optionally thickened region 62 is
Of course, it depends on the mass added to bring the head to its final weight.

The final golf club has improved vibration damping, which dampens the vibrational frequencies of energy resulting from ball striking. This alters the beating sound and also improves the playing comfort and feel of metal wood compared to conventional metal wood.

13 to 15 show another embodiment of a wood type hollow metal club head 50 'according to the present invention. In this embodiment, the liquid mixture produced by the mixing system 100 shown in Figure 2 is metered and dispensed into the hollow club head hosel opening 58. The liquid can also be dispensed directly from the nozzle 114 of system 100, or an injector. In this embodiment, the entire inner surface of the club head is not coated with elastomeric material. Instead, only the rear surface 60A of the ball striking surface 60 is covered by the layer 5 of elastomeric material.
It is covered with 4 '(FIG. 15). This can typically be done by positioning the club head facing the horizontal surface 140 after the required amount of liquid material has been dispensed into the inside of the club head.
The liquid material may be dispensed into the hosel opening after placement in the position shown in FIG.

Once the required amount of liquid material has been dispensed into the hosel opening and the club head has been positioned as shown in FIG. 13, the liquid is sized to cover the inner surface of surface 60. And to a layer depth determined by the amount of material dispensed into the club head. A typical thickness is from 5 mils to 10 mils, but this thickness is adjusted accordingly to add the desired weight to the club head to the desired weight. Then, as the club head is weighed, an additional amount of liquid elastomeric material is dispensed into the hosel opening to bring the club head to the desired weight.

FIG. 14 illustrates an oven curing step in the process for making the head 50 ', where the head is heated for a time such that the liquid material is in the solid state. For the exemplary materials described above, the head is 160
Bake only in the temperature range of ° F to 200 ° F for 15 minutes to 2 hours. After the material has solidified, the head 50 'is removed from the oven and allowed to cool, and the shaft is tuned in a conventional manner to complete the manufacturing process.
It is fixed to 8.

16-22 illustrate another embodiment of the present invention in which a layer of elastomeric material lines a cavity 20 that lines an iron-type head club 200.
Used for 2. The "iron" head 200 is typically made of stainless steel or its alloys, ceramics, A
Made of materials such as BS. One preferred material is stainless steel, which is forged into the shape shown in FIG.

FIG. 17 is a cross-sectional view of the iron head 200, the base surface 204 of the cavity 202, and the ball striking surface 206 of the club. In this exemplary embodiment, the base surface 204 of the cavity is the ball striking surface 206.
Is almost parallel to. As a result, by placing the surface 206 of the club on the horizontal fixed surface 220, it is possible to easily position the club head 200 so that the base surface of the cavity becomes horizontal. Cavity base surface 204
If is not parallel to surface 206, it is fixed at an angle to the horizontal to position surface 206 horizontally. Alternatively, a method of positioning the surface 204 at an offset angle to the horizontal can be used to provide the desired weighting by providing one region of the cavity with a thicker elastomer layer than the other. .

The same elastomeric product is used to provide an elastomeric layer in the cavity 202 as described above in connection with the wood-type club head embodiment described in connection with FIGS. However,
This product is often aesthetically unpleasing because it cures in a hazy gray and the elastomeric layer is visible in the finished golf iron. Therefore, it is often desirable to use an elastomeric product that cures in a relatively transparent state. Such products are commercially available from the same vendors as the products described above, under the product WC-575 A
/ B, available as an aliphatic polyurethane elastomer. It is supplied as parts A and B, which form an elastomeric liquid material mixed together. This elastomer is a transparent and colorless urethane material,
Colored with dyes to color when required in a particular club application.

FIG. 19 is a simplified representation of a system 230 for mixing elastomeric material components. The mixing of the two parts A and B (from each container in each part not shown in FIG. 19) is done by a mixer 232.
The mixed liquid product is pumped into a container 236 by a transfer pump 234, which is part of the mixer in this example. The container 236 is evacuated to the vacuum chamber 23 because the mixing action typically causes air bubbles to become trapped within the liquid, which impairs the appearance of the clear, cured elastomer.
8 is placed inside. The vacuum chamber is evacuated by the suction pump 239, and the air bubbles are drawn out of the mixed liquid. The mixture is then dispensed via a metering pump 242 which operates at timed intervals to dispense the metered liquid material from the container for use. Pump 234, 23
A schematic of control panel 244 is shown in FIG. 19 to exemplify a device for controlling 9 and 242.

FIG. 20 shows the iron club head 200 positioned on a fixed surface 220 after the required amount of liquid elastomeric material has been dispensed into the cavity 202. The amount of material is sufficient to cover the base surface 204 of the cavity, typically on the order of 1/16 inch to 1/4 inch deep, and in certain applications the elastomer is substantially. Packed in the cavity. Also, in certain applications, the weight of the final club is determined by the need to add some weight to the club head to a predetermined weight, thus determining the particular amount of elastomer. This is determined by weighing the club head after the liquid has been dispensed and before solidification has occurred, with the liquid added as needed to bring the club head to a given weight. The elastomeric material is then cured with its head in the position shown in Figure 21 until the elastomeric material solidifies. This is as illustrated by the oven 240 in FIG. 21, where the head is at 1 ° C., for example 160 ° F. to 200 ° F. to accelerate curing.
Heated for 5 minutes to 2 hours. After the liquid has cured, the head is removed from the oven to complete curing in air. The resulting completed club is shown in FIG.

23 to 27 show still another embodiment of the present invention, which is a putter type club head 2
An absorbing elastomer layer 256 is used in the cavity 252 that lines the ball striking surface of the ball 50. In this exemplary application, a logo (eg, "GOLF C
O. )) Is attached to the base surface 258 of the cavity and the elastomer layer 2
56 is used for the label. Elastomer layer 256
As shown in cross-section in FIG. 24, which shows the putter 250 prior to using, the label is protected from the various components by having a transparent or tinted elastomer layer 256. Typically, the thickness of layer 256 is significantly greater than that used in wood heads, and in this illustrated embodiment substantially fills the cavity. An example layer thickness is 1/16 inch to 1/4 inch.

The process for using the elastomeric layer 256 is shown in FIGS. In the illustrated embodiment, the base surface 258 of the cavity is the ball striking surface 25.
4 and parallel. The surface 254 of the club head 250 rests on a horizontal stationary plate 262 and also positions the base surface 258 horizontally. The elastomeric material that has been mixed and air bubbled using the apparatus shown in FIG. 19 is dispensed into the cavity 252 to substantially fill the cavity. The liquid elastomeric material forming layer 256 is then cured to the solid state. The curing is performed by the curing oven 270 shown in FIG.
It can be accelerated by using at a temperature of 40 ° F. to 160 ° F. for 15 minutes to 2 hours or longer. The completed putter head is shown in cross section in FIG.

By using the elastomer damper layer on the outer cavity surface, the weight of the club head can be adjusted to a desired weight while protecting against rust and preventing the accumulation of mud. Further, tinting the layers allows the cavities of the club head to be tinted as desired.

Needless to say, the above-described embodiment is merely an example of a specific embodiment representing the principle of the present invention. It goes without saying that those skilled in the art can easily envision other configurations according to these principles without departing from the scope of the technical idea of the present invention.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a wood type golf club according to the present invention.

FIG. 2 is a simplified schematic diagram of an exemplary system for injecting liquid state vibration damping material into a hollow wood-type golf club head.

3 is a cross-sectional view of a hollow wood-type golf club head illustrating the process of injecting a liquid vibration damping material into the golf club head using the system of FIG.

FIG. 4 is an illustration of a process of rocking a golf club head to ensure that the liquid covers the inner surface of the hollow club head after the liquid material has been injected.

5A and 5B are illustrations of a process of removing excess liquid vibration damping material using a flow of compressed air.

FIG. 6 is an explanatory diagram of a process of measuring a club head after removing an excessive amount of liquid.

FIG. 7 is an illustration of a process of adding an amount of liquid material to bring the weight of the club head to a desired weight.

FIG. 8 is an explanatory diagram of a step of tilting and positioning the club head so that excess liquid flows to a desired position of the hollow club head.

FIG. 9 is an explanatory diagram of a process of curing a liquid vibration damping material in an oven heated to a high temperature while tilting the club head.

10 is a cross-sectional view of the club head of FIG.

11 is an enlarged view of the area of the club head indicated by imaginary circle 11 in FIG.

12 is an enlarged view of the area of the club head indicated by phantom circle 12 in FIG.

FIG. 13 is an illustration of steps of another method for making a hollow wood-type golf club according to the present invention.

FIG. 14 is an explanatory diagram of a heating / curing step in another method.

FIG. 15 is a cross-sectional view of a hollow wood type golf club according to another method of FIGS. 13 and 14;

FIG. 16 is a rear view of the golf iron club head behind the ball striking surface.

17 is a cross-sectional view taken along the line 17-17 in FIG.

FIG. 18 is a cross-sectional view of an iron showing a ball striking surface on a flat horizontal surface in preparation for using an elastomeric material for vibration damping.

FIG. 19 is a schematic diagram of a system for dispensing an elastomeric product in liquid form.

20 is an illustration of the club head of the iron of FIG. 18 with a layer of liquid elastomeric material used in accordance with the present invention within the cavity of the iron.

21 is a schematic illustration showing an oven curing process for curing the elastomeric material used as shown in FIG. 20. FIG.

FIG. 22 is a cross-sectional view of the iron shown in FIGS. 20 and 21 with a layer of cured elastomeric material used in the iron cavity according to the present invention.

FIG. 23 is a rear view of a putter type club head showing cavities that line the ball striking surface.

FIG. 24 is a cross-sectional view of the putter taken along line 24-24 in FIG.

FIG. 25 is a cross-sectional view of a putter head showing a ball striking surface on a flat horizontal surface with a layer of elastomeric material for vibration damping of liquids used in cavities.

FIG. 26 is an illustration of a schematic representation of an oven cure process for curing the elastomeric material used as shown in FIG. 25.

27 is a cross-sectional view of the putter shown in FIGS. 25 and 26 with a layer of cured elastomeric material used in the cavity of a putter according to the present invention.

[Explanation of symbols]

 50 club head 52 shell 54 layer 56 cavity 58 hosel opening 100 system 104 container 106 container 120 tube 122 nozzle 150 oven 202 cavity

Claims (34)

[Claims] 1. A club shaft and a "wood" type club head, the club head having a hollow shell defining a ball striking surface and a head body, the shell defining an inner surface defining a hollow cavity. The inner side surface faces the ball striking surface and has a surface area having an area of at least the same size as the ball striking surface; and the inner side surface is fixed to the surface area and covers substantially the entire surface area. A vibration damper composed of a thin layer of an elastomer material, wherein the thin layer is for damping vibration generated by hitting a golf ball on a ball striking surface. "Wood" type golf club. 2. The golf club of claim 1, wherein the thin layer has a thickness in the range of 1/5000 inch to 1/10000 inch. 3. The golf club according to claim 1, wherein the elastomeric material is a polyurethane elastomer. 4. The golf club of claim 1, wherein the elastomeric material has a Shore hardness ratio of 70-72. 5. The golf club of claim 1, wherein the shell is made of metal. 6. A step of providing a hollow "wood" type shell club head having a hosel with a hosel opening defined therein, said shell club head comprising an inner hollow cavity and an outer hollow cavity. Defining a ball striking surface, the hosel opening communicating with the cavity, the shell club head including an inner shell surface defining the cavity, the inner shell surface facing the ball striking surface and Including a surface region whose area is at least as large as the ball striking surface, and dispensing a required amount of elastomeric material in a uncured state through the hosel opening into the cavity. A step of holding the club head so that the inner surface region is substantially horizontal, the required amount of the liquid state being A step of elastomeric material is pooled in the cavity covering the inner surface area, while maintaining the club head such that the inner region is substantially horizontal, and curing the elastomeric material,
Fixing a thin layer of solid elastomer to substantially the entire surface of the inner surface, thereby providing a vibration damping function, and attaching a club shaft to the hosel. How to make a vibration damped hollow "wood" type golf club. 7. The step of curing the elastomer comprises:
7. The method of claim 6 including firing the club head at an elevated temperature in an oven for a duration of time. 8. The method of claim 6, wherein the elastomer is a polyurethane elastomer. 9. The method of claim 6, wherein the elastomer has a Shore hardness ratio of 70-72 for the elastomeric material. 10. The method of claim 6 wherein the elastomeric layer has a thickness in the range of 1 part in 5000 to 1 part in 10000. 11. A "iron" having a club shaft and a head body defining a ball striking surface and a hollow cavity lining the ball striking surface, the cavity partially defined by a base surface of the cavity. A club head of a type, and a vibration damper fixed to the base surface of the cavity and composed of a layer of elastomeric material covering substantially the entire base surface of the cavity, the layer comprising: A vibration-damped "iron" type golf club, which is for damping vibrations generated by hitting a golf ball. 12. The golf club of claim 11, wherein the layer has a thickness in the range of 1/16 inch to 1/4 inch. 13. The golf club of claim 11, wherein the layer substantially fills the cavity. 14. The golf club according to claim 11, wherein the elastomer is a polyurethane elastomer. 15. The golf club of claim 11, wherein the elastomer is an elastomeric material having a Shore hardness ratio of 70-72. 16. The golf club of claim 11, wherein the club head body is made of metal. 17. The method of claim 11 wherein the base cavity surface is substantially parallel to the ball striking surface. 18. Providing an "iron" type club head body that defines an outer ball striking surface and an outer hollow cavity that lines the surface and that includes a base cavity surface that defines the cavity, and a club. Positioning the head body so that the surface of the base cavity is substantially horizontal, and distributing a required amount of the elastomeric material in the liquid in the uncured state into the cavity so that the elastomer pools in the base of the cavity. And forming a layer covering the base cavity surface, and curing the elastomer material into a solid state while holding the club head so that the inner region is substantially horizontal, Defines a layer of solid elastomer adhered over substantially the entire surface, which reduces vibration A method of making a vibration damped hollow "iron" type golf club, which comprises the step of providing a damping function and the step of attaching the club shaft to a hosel. 19. The method of claim 18, wherein curing the elastomer comprises firing the club head at an elevated temperature in an oven for a duration of time. 20. The method of claim 18, wherein the elastomer is a polyurethane elastomer. 21. The method of claim 18, wherein the elastomer is an elastomeric material having a Shore hardness ratio of 70-72. 22. The method of claim 18, wherein the elastomeric layer has a thickness of 1/16 inch to 1/4 inch. 23. The method of claim 18, wherein the layer substantially fills the cavity. 24. A putter club head having a club shaft and a putter head body defining a hollow cavity lining the ball striking surface and the ball impact surface, the cavity being partially defined by the base surface of the cavity. And a vibration damper composed of a layer of an elastomeric material covering substantially the entire base surface of the cavity, the layer being for damping vibrations caused by hitting the ball striking surface with a golf ball. A vibration-damped golf putter club characterized by: 25. The golf club of claim 24, wherein the elastomeric material is a polyurethane elastomer. 26. The elastomeric material is 70-72.
25. The golf club of claim 24, having a Shore hardness ratio of. 27. The golf club of claim 24, wherein the club head body is made of metal. 28. The golf club according to claim 24, wherein the base cavity surface is parallel to the ball striking surface. 29. The golf club of claim 24, having a thin label insert attached to the base cavity surface and the vibration damper layer attached to the label insert. 30. The golf club of claim 24, wherein an elastomeric layer substantially fills the cavity. 31. Providing a club head body for a putter comprising an outer ball striking surface and an outer hollow cavity lining the surface and a base cavity surface defining the cavity; and a club head body. Positioning the base cavity surface to be substantially horizontal; dispensing a required amount of elastomeric material in the liquid in the uncured state into the cavity, pooling the elastomer into the base of the cavity, and Forming a layer overlying the base cavity surface, and curing the elastomeric material in a solid state while holding the club head such that the inner region is substantially horizontal, thereby substantially removing the base cavity surface. Defines a layer of solid elastomer adhered to the entire surface, which serves to dampen vibrations. A method of making a vibration-damped golf putter club, comprising the steps of holding and attaching the club shaft to a hosel. 32. The method of claim 31, wherein curing the elastomer comprises firing the club head at an elevated temperature in an oven for a duration of time. 33. The method of claim 31, wherein the elastomer is a polyurethane elastomer. 34. The method of claim 31, wherein the elastomer has a Shore hardness ratio of 70-72 for the elastomeric material.