CA2349968A1

CA2349968A1 - Golf club head with weighting member and method of manufacturing the same

Info

Publication number: CA2349968A1
Application number: CA002349968A
Authority: CA
Inventors: Uday V. Deshmukh
Original assignee: Callaway Golf Co
Current assignee: Topgolf Callaway Brands Corp
Priority date: 2000-05-31
Filing date: 2001-05-31
Publication date: 2001-11-30
Also published as: JP2002017916A; CN1338321A; US6440010B1; US20020042307A1; US6508978B1; KR20010109214A; AU4811101A; DE10127190A1

Abstract

The use of hot pressing for weighting of a golf club head is disclosed herein.
The preferred weighting material is a multiple component material that includes a high-density component and a binding component. A preferred multiple component material includes tungsten and tin. The hot pressing process is performed in an open air environment at standard atmospheric conditions.

Description

TITLE OF THE IiWENTION
GOLF CLUB HEAD WITH WEIGHTING MEMBER
AIVD VfETHOD OF MANFUCATURING THE SAME
(Corporate Docket Number PU 1120) CROSS REFERENCES TO REL.~TED APPLICATIONS
Not Applicable STATEMENT RECJ.ARDING FEDERALLY SPONSORED
RESE~,RCH OR DEVELOPMENT
Not Applicable BACKGROUND OF THE IT,'VENTION
Meld of the Invention The present invention relates to a golf club. More specifically, the present invention relates to a golf club with a weighting member composed of multiple materials.
Description of the Related Art Golf club designs are constantly evolving with the primary purpose to improve a golfer's performance. While the improvements may address a number of areas, a designer strives to design a more forgiving golf club. Forgiveness in a golf club may be achieved by shifting the center-of gravity of a golf club to a de~;irable location, and creating a larger moment of inertia.
It is di~cult to increase forgivewess in a golf club head composed of a homogeneous or monolithic material, such as stainless steel, since there is a limit on the overall weight of a golf c'ub acceptable to the typical golfer. To overcome this difficulty, designers have resorted to combining different materials (high density and low density) to achieve the desired center-of-;cavity and large moment of inertia. A very high-density material provides a designer with the greatest freedom in improving the performance of a golf club head since Less volume is needed to achieve the proper weighting. The most economical, commercially available material with a very high density is tungsten, which has a density of 19.3 grams per cubic centimeter.
One challenge in using heterogeneous materials is the ability to join the materials together in a golf club head. Numerous techniques have been created by the golf industry to join heterogeneous materials in a golf club head. One example is the GREAT BIG
BERTHA~
~l LINGSTEN-TITANIIJMT'~ irons, developed by the Callaway Golf Company of Carlsbad, (:alifornia, which used a screw to attach a tungsten block to the rear and sole of a titanium iron.
t~nother example is the GREAT BIG BERTHA~ TUNGSTEN-INJECTEDTM HAWK EYE ~
i:,ons, also developed by the Callaway Golf Company, which feature an internal cavity with tiungsten pellets in a solder, as set forth in co-pending U.S. Patent Application Number 09/330,292, for an Internal Cavity Tungsten Titaniu.rn Iron , filed on June 11, 1999. An example of a wood is the GREAT BIG BERTH.A~ HAWK EYE~ drivers and fairway woods, also developed by the Callaway Golf Company, which use a tungsten screw in the sole of a titanium c:Ub head body. Other techniques use adhesives to join the materials, press fit the materials, 1~ braze the materials, or structurally hold one material piece within another material piece using »zdercuts or pockets.
For the most part, these techniques require a precisely machined weighting piece to fit within a precise location on a golf club head. The most economical method is to cast a golf club hf:ad body with a cavity for the weighting piece and attaching the weighting piece with a screw.
However, casting tolerance are low, and require either machining of the cavity itself, or machining of the weighting piece to tit each cavity. The use of softer materials is undesirable since this creates difficulty in finishinc; the final product due to smearing of such soft materials during grinding of the golf club head.
Further, a co-casting process, where the weighting piece is incorporated in the mold prior to pouring the base metal, is very problematic depending on the materials since the weighting piece is relatively cold when the hot liquid base metal is cast around it causing thermal shock.
f~lso, thermal expansion mismatch of materials is a problem with co-casting of heterogeneous rnaterials. Other problems arise during re-shafting, where the golf club head is heated to remove the shaft. Such heatins will result in low melting temperature materials (epoxies ~:,r.: s:.lder) to flow, resulting in the possible movement of weighting pieces.

BRIEF SUivfI~IARy OF THE INVENTION
The present invention allows for a golf club head to be easily weighted without precisely machined weighting components. The present invention is able to accomplish this by forming a weighting member composed of a mufti-component material into the golf club head by applying pressure to the mufti-component material while it is in a cavity of the golf club head.
The most general aspect of the present invention is a golf club head with a body and a.
weighting mem~~r. The body has a striking plat;,, a heel end a toe end and a cavity. The vreighting member is composed of a mufti-component material and is disposed in the cavity of the body.
Another aspect of the present invention is a cavity back golf club head having a body and a weighting member. The body has a striking plate, a toe end, a heel end and a main rear cavity opposite the striking plate. A top wall, a bottom wall, a heel wall and a toe wall define the main rear cavity. The bottom wall has a second cavity with a predetermined configuration. The weighting member is disposed within the second cavity and occupies the entire cavity. The weighting member is composed of a mufti-component material.
Yet another aspect is a method for manufacturing a golf club head. The method includes introducing a mufti-component powderipellet mixture into a cavity on a body of a golf club head, anal applying a predetermined amount of force to the mufti-component powder/pellet mixture to compact the mufti-component powder/pellet mixture within the cavity and form a weighting member. The mufti-component powder/pellet mixture may also be heated to a predetermined ,l temperature for hot pressing of the mufti-component powder/pellet mixture within. The predetermined temperature is above or closest to the melting temperature of one component of the mufti-component powder/pellet rruxture.
The mufti-component powder,!pellet mixture may be composed of a high-density component and a binder component. One variation of the mufti-component powder/pellet mixture may be composed of tungsten and tin, or alternatively composed of tungsten and:a tin bismuth material.
Having briefly described the prose:.: invention, the above and furtl-~er objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following ~~etailed description of the invention when taken in conjunction with the accompanying drawings.

PUl 120 BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a rear plan view of a golf club head of the present invention.
FIG. 2 is a front plan view of vhe golf club head of FIG. 1.
FIG. 3 is a top perspective view of the golf club head of FIG. 1.
FIG. 4 is a heel end perspective view of the golf club head of FIG. 1.
FIG. 5 is a toe end perspective view of the golf club head of FIG. 1.
FIG. 6 is a bottom perspective view of the golf club head of FIG. 1.
FIG. 7 is a cross-sectional view of the golf club head of FIG. 1 along line 7-7.
FIG. 8 is a rear plan view of an alternative embodiment of the golf club head of the present mvenrion.
FIG. 9 is a cross-sectional vievf of the golf club head of FIG. 8 along line 9-9.
FIG. 10 is a flow chart of the process of the present invention.
FIG. 11 is a rear plan view of an unfinished golf club head of the present invention.
FIG. 12 is a cross-sectional view of the unfinished golf club head of FIG. 11 along line 12-12.
FIG. 13 is a rear plan view of the unfinished golf club head of FIG. 11 with the powder precursor material therein.
FIG. 14 is a cross-sectional view of the unfinished golf club head of FIG. 13 along line 14-14 with a punch engaged therewith.
FIG. 15 is a view of a putter golf club head.

FIG. 16 is a view of a wood s;olf club head.
FIG. 17 is a graph of Relative Density versus Volume percent of tin.
FIG. 18 is a graph of Relative: Density versus Volume percent of tin.
FIG. 19 is a graph of Relative. Density versus Volume percent of tin.
S

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIGS. 1-7, a golf club head is generally designated 20. The golf club head 20 is a cavity-back iron with a body 22 and a weighting member 24. The golf club head 20 has a heel end 26, a toe end 28 and a sole 29. On the front of the body 22 is a striking plate 30 that has a plurality of scorelines 32 therein. A hosel 34 for receiving a shaft 36 is located on the heel end 25 of the golf club head 20. The rear of the golf club head 20 has a main cavity 38 that is defined b:y a top wall 40, a bott~:n wall 42, a heel wall 44 and a toe wall 46. The golf club head 20 also h~~s an optional undercut recess 48 circmnventing and openly exposed to the main cavity 38.
The weighting member 24 is composed of multiple component powder or pellet mixture that is pressed within a cavity 25 (shown in FIG. 11 ) of the body 22. The cavity 25 is preferably open to the sole 29 and the bottom wall 42. However those skilled in the pertinent art will recognize that the cavity 25, and hence the weighting member 24, may be disposed in numerous locations to provide a desired affect. As shown in FIG. 7, the weighting member 25 locates a lay-ge percentage of the mass of the golf club head 20 in the lower center of the golf club head 20 thereby lowering the center of gravity of the golf club head 20 to make it more forgiving for a go lfer.
An alternative embodiment of the golf club head 20a of the present invention is illustrated in FIGS. 8 and 9. The golf club head 20a is a blade-style iron as compared to the cavity-back iron of FIGS. 1-7. The gol:E'club head 20a of FIGS. 8 and 9 does not have a cavity 38, nor does it have an undercut 48. Thf: weighting member 24a is disposed annularly about the rear 39 of the body 22. Further, the cavity 2~a containing the weighting member 24a is open only to the rear 39 and not the sole as in the previous embodiment. The annular weighting member 24a allows for the blade stylev golf club head 20a to have perimeter weighting similar to a cavity-back iron, and thus the forgiveness of a cavity-back iron while having the traditional appearance of a blade iron. The annular weighting member 24a will occupy a greater volume of the golf club head 20a than the weighting member 24 of FIGS. 1-7, and thus will also have a ;;neater percentage of the mass of the golf club head 20a. The weighting member of the present Invention may occupy various contoured eavi~ies of golf club heads due to its unique manufacturing method.
FIG. 10 illustrates a flow than: of the process of the present invention for producing a s;olf club head 20 or 20a with a weighting member 24 or 24a composed of a multiple component powder or pellet mi~cture. The process 200 begins with providing a golf club head 20, preferably prepared by a conventional investment casting process at block 202. However, those skilled in the pertinent art will recognize that the golf club head 20 or 20a may be prepared through other 1 ~ techniques well know in the golf industry, such as forging. The golf club head 20 may be composed of stainless steel, titanium, titanium alloys, zirconium, zirconium alloys, copper, nickel, cobalt alloys, or like materials. The golf club head 20 is cast to have a cavity 25, as shown in FIG. 11, and preferably has a lip ~ 1, as shown in FIG. 12, for containing the mi<Yture.
The lip ~ 1 is removed during the finishing process. The cavity 2~ has a predetermined volume according to the amount of mass needed from the weighting member 24 for the golf club head

2(). At block 204, the precursor powder materials for the multiple component powder or pellet PUl 120 mixture are compacted for placement into the cavity 25. The mixture may be composed of powders, pellets or a mixture thereof. The precursor powder or pellet materials are composed of a high-density component in various panicle sizes (ranging from 1.0 mm to 0.01 mm) for achieving low porosity for the weighting member 24. The preferred high-density component is tungsten which has a density of 19.3 grams per cubic centimeter ("g/cm3"), however other high-density materials may be used such as molybdenum ( 10.2 g/cm3), tantalum ( 16.7 g/cm'), platinum (21.4 g/cm'), gold ( 19.3 g/crn'), silver ( 10.3 g/cm'), and the like. Additionally, high-density ceramic powders may be utilized as the high-density cumponent. The amount of high-density component in the mixture may range from 5 to 9~ percent of the volume of the weighting member 24.
In addition to a high-density component such as tungsten, the multiple component powder or pellet mixture is composed of a binding component such as tin (density of 7.31 g/cm') ~~r other comparable material. The binding component in the multiple component powder or pellet mixture may range from 4 to ~0 percent of the volume of the weighting member 24. The overall density of the weighting member 24 will range from 1 l.Og/cm3 to 17.~
g/cm', preferably between 12.~ g/cm' and 1~.9 g/cm3, arid most preferably 15.4g/cm'.
Returning to FIG. 10, the powders are thoroughly mixed to disperse the binding component throughout the multiple component powder or pellet mixture. The multiple component powder or pellet mixture may be pre-compacted into slugs for positioning and F~ressing within the cavity 25 at block 206, and as shown in FIG. 13. Higher densities are achieved by pre-compacting the multiple component powder or pellet mixture prior to placement within the cavity 25. At block 206, the mixture is pressed within the cavity 25 at a pressure between 10,000 pounds per square inch ("psi") to 100,000 psi, preferably 20,000 psi to 60,000 psi, and most preferably 50,000 psi. As shown in FIG. 14, a punch 57 is used to exert the pressure on the mixture to compact the mixture to form the weighting member 24.
Once the multiple component powder or pellet mixture is pressed within the cavity 25, at block 208 the unfinished golf club head 20b may optionally be placed within a furnace for heating of the multiple component po~Nder or pellet mixture under standard atmospheric conditions and in air. l~tore precisely, the process of the present invention does not require a ~racuum nor does it require an inert or reducing environment as used in the liquid phase sintering processes. In the furnace, the multiple component powder or pellet mixture is heated for 1 to 30 rninutes, preferably 2 to 10 minutes, and most preferably 5 minutes with the punch 57 maintaining a constant pressure on the mixture. The furnace temperature for melting at Least one component of the mixture is in the range of 300°F to 550 °F, and is preferably at a temperature of approximately 450°F. The one component is preferably the binding component, and it is heated to its melting temperature to liquefy as shown in FIG. 14. However, those skilled in the art will recognize that the temperature may vary depending on the composition of the multiple component powder or pellet mixture. 1?referably the binding component is tin, and the hot pressing occurs at 450°F to allow the tin to fill in the cavities of the multiple component powder or pellet mixture to reduce porosity and thus increase the density of the weighting member 24.
A.s the tin liquefies, the tungsten (melting temperature of 3400 °C), or other high-density component, remains in a powder form.

PUl 120 At block 210, the unfinished golf club head with the weighting member 24 therein is finished through milling, grinding, polishing or the Like. The lip ~ 1 is removed at this stage of the process. Those skilled in the art will recognize that the density of the weighting member 24 will change depending on the particular club within a set of irons, or fairway wood or putter.
The density is manipulated through modifying the amount of binding component, such as tin, and varying the pressure and temperature as shown in FIGS. 17-19.
FIGS. 17-19 illustrate graphs of the compositions of the multiple component powder or pellet mixture, at different comrositions and under different pressures and temperatures. The y-axis of each is the Relative Density that is the percent of theoretical or expected density achieved by the measured density. The processing was conducted at standard atmospheric conditions (1 ;atmosphere) and in air. The theoretical or expected density is the density if mixture was processed in a reducing environment under high pressure. The present invention is able to achieve between 70% to 99% of the theoretical density by using a method that does not require a reducing environment and high pressures.
FIG. 17 illustrates the Relative Density versus the volume of tin in the mixture of just tin a~.nd tungsten (disregarding porosity) that undergoes pressing at X0,000 psi.
The highest density, 14.6g/cm', is achieved at 22% volume tin whereas the highest relative density (99%), l2.Sg/cm', i;s achieved at ~0%volume tin.
FIG. 18 illustrates the Relative Density versus the volume of tin in the mixture of just tin and tungsten (disregarding porosity) that undergoes pressing at X0,000 psi and 100,000 psi. The highest density, 15.4g/cm', is achieved at 22% volume tin whereas the highest relative density, 99% ( 13.9g/cm3), is achieved at 40% volume tin, and at 100,000 psi.
FIG. 19 illustrates the Relative: Density versus the volume of tin in the mixture of just tin and tungsten (disregarding porosity] that undergoes pressing at 50,000 psi and 100,000 psi, and is processed at room temperature and at 4~0°F. The highest density, 16.6g/cm', is achieved at 12% volume tin whereas the highest relative density, 99% (16.4g/cm'), is achieved at 2~%
volume tin, at 100,000 psi and at a temperature of 4~0°F. FIG. 19 illustrates that hot pressing provides a weighting member ?4 that has the highest density and, the highest relative density.
Although the present invention lm, been described in reference t~ irons, those skilled in the pertinent art will recognize that the present invention may be utilized with putter heads 91 and wood heads 93 as illustrated in FIc;~S. 1 ~ and 16 respectively.
From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present i:zvention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, r,.he embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims.

Claims

We claim as our invention:

1. A golf club head comprising:
a body with a striking plate, a heel end a toe end and a cavity; and a weighting member disposed in the cavity of the body, the weighting member composed of a pressed multiple component powder material comprising tungsten in an amount of 50 to 95 % volume of the multiple component powder material and tin in an amount of 5 to 50 % volume of the multiple component powder material.

2. The golf club head according to claim 1 wherein the weighting member has a density ranging from 12.0 g/cm3 to 17.0 g/cm3.

3. The golf club head according to claim 1 wherein the weighting member has a density that is 80% to 99% of the theoretical density of the multiple component powder material.

4. The golf club head according to claim 1 wherein the weighting member has a density of approximately 16.7 g/cm3.

5. The golf club head according to claim 1 wherein the golf club head is an iron.

6. The golf club head according to claim 1 wherein the golf club head is a driver, fairway wood or a putter.

7. The golf club head according to claim 1 wherein the golf club head is a blade iron and the weighting member is an annular structure about the rear wall of the blade iron opposite a striking plate of the blade iron.

8. The golf club head according to claim 1 wherein the weighting member has a density ranging from 15.5 g/cm3 to 16.7 g/cm3.

9. The golf club head according to claim 1 wherein the weight member has a porosity that is less than 10% of the volume of the weighting member.

10. The golf club head according to claim 1 wherein the tungsten component is 80-90 volume percent of the weight member and the tin is 10-20 volume percent of the weight member.

11. The golf club head according to claim 1 wherein the tungsten component is approximately 78 volume percent of the weight member and the tin is approximately 22 volume percent of the weight member, and the density is approximately 16.0 g/cm3.

12. A golf club head comprising:
a body having a striking plate, a toe end, a heel end, a main rear cavity opposite the striking plate, the main rear cavity defined by a top wall, a bottom wall, a heel wall and a toe wall, the bottom wall having a second cavity with a predetermined configuration; and a weighting member disposed within the second cavity and occupying the entire cavity, the weighting member the weighting member composed of a pressed multiple component powder material comprising tungsten in an amount of 50 to 95 % volume of the multiple component powder material and tin in an amount of 5 to 50 % volume of the multiple component powder material.

13. The golf club head according to claim 12 wherein the main rear cavity further comprises an undercut recess into at least one the top wall, bottom wall, toe wall or heel wall.

14. The golf club head according to claim 12 wherein the body is composed of material selected from the group consisting of titanium, titanium alloy, steel, zirconium, zirconium alloy, nickel, nickel alloy, copper and copper alloy.

15. A method for manufacturing a golf club head, the method comprising:
introducing a multiple component material into a cavity on a body of a golf club head; and pressing the multiple component material within the cavity at a pressure ranging from 20,000 psi to 150,000 psi.

16. The method according to claim 15 further comprising heating the multiple component material during the pressing of the multiple component material within the cavity.

17. The method according to claim 16 wherein the multiple component material is heated to a temperature ranging from 300°F to 600°F.

18. The method according to claim 15 wherein pressing the multiple component material is performed in an open air environment at one atmosphere of pressure.

19. The method according to claim 15 wherein pressing the multiple component material is performed in an inert environment.

20. The method according to claim 15 wherein the golf club head is an iron, putter, driver or fairway wood.

21. The method according to claim 15 wherein the multiple component material consists of tungsten and tin, the tungsten is 80-90 volume percent of the weight member and the tin is 10-20 volume percent of the weight member.