WO1999028004A1

WO1999028004A1 - Golf shaft and method of making same

Info

Publication number: WO1999028004A1
Application number: PCT/US1998/027868
Authority: WO
Original assignee: Smith, Earl, F.
Priority date: 1997-12-01
Filing date: 1998-12-01
Publication date: 1999-06-10
Also published as: AU2308699A

Abstract

A golf shaft comprised of an inner core member (1) made of steel and the like, and an outer member (2) made of a composite material which covers said inner core, said shaft members being combined to provide a golf shaft having the consistency and durability of performance of a conventional steel golf shaft and the lightweightness of a conventional composite golf shaft.

Description

GOLF SHAFT AND METHOD OF MAKING SAME

The present invention pertains to the long felt need for innovations and improvements in golf shafts and particularly those defined and termed "composite" shafts. The prior and current art composite shafts lack consistency of performance in comparison to steel shafts of comparable stiffness values. In other words, consistency and comparable stiffness values of steel and composite shafts rarely exist in the marketplace and industry. Another existent long felt need concerning composite shafts is consistency of composite shafts of the same stiffness value as provided by manufacturers of composite golf shafts.

The present invention satisfies these long felt needs of the prior and current art by providing a distinct and novel "combination" golf shaft with same or new stiffness and flex choice characteristics as are available in prior art steel golf shafts, and by providing a novel shaft construction that offers the consistency of steel shafts and the lightweightness of a composite (graphite) shafts and the like.

Discovery of the need for this invention has been made from and by my inventive methods and system known as "Precise Fit Golf Club Fitting System and Golf Shaft Selection Methods and Apparatus", U.S. Serial No. 08/863,893, filed May 28, 1997.

BACKGROUND OF INVENTION

A technological explosion, that's what they promised us. Before high tech it was persimmon or laminated woods, flat back forgings or blades, and three basic shaft flexes. In the 80's high tech came to the golf business promising us high tech results. The United States Golf Association recently revealed handicaps have not changed in 30 years according to their records. The scoring average of the PGA Tour Professionals has not changed in 25 years according to the USGA. The USGA recently questioned the claims of new equipment by the golf manufacturers. What does it mean? The results are in and those promises are mere empty words with no foundation.

I have found with testing in my inventive process, "Precise Fit Club Fitting System and Golf Shaft Selection Method and Apparatus", a patent pending process^*, a foundation for the golf industry is now a reality. There is a distinct need to supply golf shafts with like characteristic of steel and/or composite. With my inventive process there is a way to measure the true shaft response to a golfer, with this ability new shafts must evolve for the golfer. Data gathered from my inventive process has determined it is easier to properly fit someone in steel as exists by prior or current art than in a composite shaft that exists by prior or current art. Engineering techniques are very different between the construction of steel versus graphite. Therefore, consistency between the two types rarely exists. We will use the term "composite(l)" for fiberglass, graphite, wound, plate, layered, filament wound, braided, like materials or other exotic shafts for our discussion.

More and more manufacturers are introducing their clubs with shafts that look different from the competition in an effort to position their products in the marketplace as being newer and better. Unfortunately, to most golfers, "a shaft is a shaft is a shaft". My inventive process has shown time and time again in statistical information gathered, that this is not the case and nothing could be further from the truth. It's further estimated that it is not the case and nothing could be further from the truth. It's further estimated that 8 out of every 10 people have the wrong shaft in their club or set of clubs. I believe the statistics are much higher with the data my inventive process has collected.

^* U.S.S.N. 08/863,893 filed May 28, 1997 A patented system that will improve the shaft choices in your game is the answer. My "Precise Fit Club Fitting System", does just that. Any golfer can individually test any golf shaft in existence by prior art, current art or future art to assist the golfer in making the right choice for his or her game. In the past it has been difficult to explain the function of a golf shaft or how it should be fitted to a golfer particular build and swing characteristics. But now, testing by my inventive process confirms the shaft is the single most important component in a golf club as has been touted by the golf industry for years. With this ability to measure the true shaft response to a golfer, new shafts must evolve.

Currently, the three major golf shaft manufacturers in the United States that supply steel shafts to the industry are Apollo, FM Precision (formerly Brunswick) and True Temper. At present, two grades of steel shafts dominate and populate the wholesale, proprietary and retail markets, "commercial" and "pro line", terms designated by the shaft manufacturers. Although like in appearance, often in terms of quality, slight differences occur and the "commercial" is more cost effective than the "pro line". True Temper acquired most of their initial patents on steel shafts in the 1930's, and the three basic shaft flex choices, (flexes) i.e., low, mid and high in steel, still dominate the market. The industry designates different stiffnesses (1), and is normally marketed as L, R, S and X. The designation "A" has been added by the industry to denote a stiffness value between L and R. The "A" flex designation is sometimes touted as a "senior flex" by the industry. While it is important to have the stiffness of shafts as designated by the manufacturers to test with, it is my discovery and determination that through my inventive process, "Precise Fit Golf Club Fitting System", the angles/degrees as close to zero, open or closed at impact, is the primary consideration and not the stiffness as touted by the

(1) Definition Composite-anything made up of separate parts, blended together to form a product Examples, golf shaft, pool cue, fishing rod, hickey stick, etc golf industry. When testing with my inventive process in some instances, the predetermined torque value of the composite shaft can be significant when testing in the same stiffness values as dictated by current standards in relationship to angle/degrees at impact. Dynacraft Golf of Newark, Ohio, one of the major suppliers of golf components has listed in its catalogue for 1997 not less than 16 makers and suppliers of shafts. Titanium, graphite, exotic composites are offered in all sizes and shapes for the golfer to choose from. Major composite suppliers and manufacturers include Aldila, Fenwick, Fiber-X, Graffaloy, Harrison, Paragon and Rapport. Add True Temper, Apollo and FM

Precision to the list and offerings of no less than 175 different composites are offered to the discriminating buyer in composite or graphite as they are referred to for sale.

True Temper alone offers over 200 kinds, styles and variations of steel shafts in various alloy and stiffness combinations for the discriminating buyer. The three major suppliers of shafts have a total of over 360 selection of shafts in steel and other exotic materials offered in Dynacraft's catalogue alone. As more and more manufacturers introduce shafts that look different from the competition, it appears that appearance is more important than performance, in an effort to position their productsas being new and better. Cosmetics such as color of the shaft, elaborate silkscreened logos, with colorful shaft bands is the order of the day. In golf, perception is everything , reality is nothing in the golfer's world. There are estimated to be 50 million people in the world that presently play golf and it is further estimated that over 90 percent of those currently playing cannot break 100. If the golf industry was summed up it would have to be, "The result of their promises are mere empty words with no foundation".

It should be noted that in U.S. Patent No. 4,169,595 awarded to Brunswick Corp. States, "The letters X, R, S and L are commonly employed in the golf club art ot denote shaft stiffness characteristics. X stands for extra stiff, S for Stiff, R for regular and L for ladies. These terms are relative and have no commonly accepted absolute definition determination or X, R, S and L flexes in connection with the shafts of the invention as described in detail in U.S. Patent No. 4,169,595.

OBJECTS OF INVENTION

I. To produce a distinct and different combination shaft with same or new stiffness and flex characteristics as are available in a steel shaft. II. To produce a distinct and different combination shaft than can offer the consistency of a steel shaft in different stiffness and flexes.

III. To produce a distinct and different combination shaft that can offer the lightness of a graphite composite or other exotic mixture shaft.

IV. To produce a distinct and different combination shaft by blending or combining two materials together to greatly enhance the players ability to be fitted properly.

V. To produce a distinct and different combination shaft that has been now determined by my inventive process, "Precise Fit Golf Club Fitting System", is needed. In the manufacturing of steel shafts, certain consistencies and options are available to and by the manufacturer. While in the past it has been difficult to explain the function of a golf shaft, characteristics in manufacturing have changed little, while the substance in marketing have not. One of the manufacturing and marketing principles is that the "heavier the shaft, the stiffer the flex in terms of a steel shaft". One could deduce there is predictable or absolute from a players standpoint. It could be said, acceptance in the manufacturing, marketing and the marketplace with steel is based on consistency and a proven product. In the last 50 years the names that the steel shafts are marketed under has changed, but the basic product has not.

Composite shafts on the other hand do not answer to any scrutiny. With composite shafts from a manufacturing standpoint, I could change the exotic mixture and materials, if I choose, every time I invent a shaft construction. Exotic materials used in the manufacturing of composite shafts have different parameters. Unlike steel, in the construction process associated with composite shafts, the individual manufactures enjoy a much larger area of the shaft length within which to engineer and construct flex or kick point choices. In some instances 29 to 35 inches of the total length of the shaft can be and has been employed to engineer and construct the flex choices into a shaft. Formulas can be changed, cheaper materials used, more expensive materials used, add a bubble or a bulge, whatever is selected. The shaft looks the same, it has the same color, same stiffness or flex designations painted on the shaft, produced from year to year, so it must be the same shaft, right? "Perception is reality".

I find the apposite is true, such shafts are not always the same. Because of economics or new ideas with composite shafts, one could change the performance of the shaft from one quantity of manufactured shafts at any given time to the next quantity produced. They would look the same but be distinctly different. Although the promise and playing ability of composite shafts cannot be denied, there exists a problem of consistency and durability.

My patent pending process, "Precise Fit Golf Club Fitting System", allows a foundation or testing basis to develop new shafts and insure the proper selection of prior art shafts, and one can now accurately measure the two principle objectives of the golf swing: 1 ) To accurately align the club face to the target at the address position and at the impact position; and 2) Optimize the transfer of energy from the player/golfer, through the grip and the proper golf shaft, to the clubhead to the ball for maximum results of accuracy and distance, which has eluded the golf industry and is now possible with my patent pending process. Other objectives are:

To allow the manufacturers to offer the consistency of steel and the advantages of composite shafts that do not exist at this time.

To offer various options in shafts in the form of a composite, yet retain strengths inherent in steel shafts for reinforcing the tip and butt portions of the shaft which absorb the tremendous forces applied to a golf shaft when swinging.

To allow the manufacturing of a shaft that permits better reinforcing without unduly increasing the weight of the shaft. To set guidelines for shafts based on piayability of the individual golfer and not the swing weight principle. The normal swing weights range the current industry has set for guidelines is from B4 to D8 which only affects the weight of the clubhead in relation to the shaft and grip. The swing weight principle in some minds is a marketing tool only.

BRIEF DESCRIPTION OF THE DRAWING

The drawing Figure illustrates the construction and form of a preferred embodiment of my inventive "combination" golf shaft product/component for a golf club.

DETAILED DESCRIPTION OF THE INVENTION

My invention is a combination shaft constructed of a steel mandrel or inner core 1 , which could comprise a lightweight vanadium steel inner core member or part, and an outer layer part or surfaces composed by i.e., an asymmetrical interlocked winding process (braided) composite member or part. My goal is to produce an ultra lightweight steel/composite combination shaft to fit a wide range of golfers, with overall weights associated with composite/graphite type shafts and the consistency/strength characteristics of steel. To accomplish this, it is necessary to blend or combine two unlike types of shaft materials into one shaft construction. The ability to offer shafts in a steel/composite combination construction would allow consistency and greatly enhance the players ability to be fitted properly. It has been my experience with my patent pending "Precise Fit Golf Club Fitting System", testing with steel shafts and with composite shafts present a different set of problems.

Because of the consistency of steel shafts as exist by prior art, it is easier to fit an individual with less shafts being tested. Composite shafts on the other hand follow no degree of consistency of stiffness from shaft to shaft. 1 have discovered two composite shafts that are marked identically and would register different performance readings with my patent pending system. My invention will allow the manufacturers to offer the consistency characteristics of steel and the lightness of a composite shaft in a combination form. It has been my experience with my "Precise Fit Golf Club Fitting System", that only the person swinging the golf shaft and club can directly effect the many factors that affect how much or how little a shaft will flex. Golf clubs have for years been manufactured and marketed on the principle that the heavier the shaft, the stiffer the flex. While there is certainly a correlation between weight, wall thickness, and flex, my testing of many individuals leads me to conclude this is not predictable or absolute from the players standpoint. Slight design modifications in the mandrel or inner core are possible if a different variation is desired, without changing the function or total weight of the combination shaft. It has been argued by shaft manufacturers that experience by prior or current art has taught them the conventional process of determining shaft flex strictly by weight does not recognize a number of other variables that can stand in the way of producing a correctly matched set of shafts/clubs. Regarding the golf shaft, some manufacturers identify the problem as "dead weight is static measurement"; but the product - the golf shaft - is not used in a static manner. My invention is a hybrid combination steel/composite shaft that would allow a more efficient and dependable selection or range of shafts to fit the wide range of golfers. A metal of choice for the manufacturing of steel shafts has been and is 4140 high alloy carbon or carbon steel marketed by FM Precision. In such shaft construction FM Precision uses a high frequency heat source that seals the 4140 carbon steel into a homogenous seamless configuration without the use of a weld rod or brazing material. This achievement makes it possible to avoid the use of seamless materials which may be susceptible to inconsistent metallurgical composition manufacture i.e., surface blemishes, and variations in concentricity of wall thickness according to FM Precision. They further coat the inside diameter with an organic rust inhibitor. Some steel shafts have reinforced tips according to the individual manufacturers specifications. The methods and materials of shaft construction vary from manufacturer to manufacturer. During loading and unloading of the golf shaft during the entire swing, and especially the downswing, tremendous forces of acceleration and deceleration take place. Some manufacturers have claimed for that reason it is more important to determine dynamically the actual flex of each individual shaft when it is put into motion. My patent pending "Precise Fit Golf Club Fitting System" not only addresses the question, it also answers it. My system has the ability to measure any shaft in any combination of steel or composite or any other makeup and determine if a golfer can play with that shaft. A steel/composite shaft further enhances players to be fitted with shafts that will greatly improve and even guarantee piayability or performance. With my patent pending process, the conventional flexibility identification system used by the industry currently comes under further question. It follows that the Frequency Coefficient Matching System marketed by FM Precision would be redefined in some way. There has been, and is now, a need to develop a series of golf shafts combining steel and composite materials into a combination shaft to enhance a wide range of players/golfers abilities and choices. The object of my invention is to create a hybrid or a cross between steel and composite materials that would afford the consistency/strength/durability and piayability of steel and having characteristics of a lighter composite shaft in a combination form. Shafts, as exist by prior and current art, include aluminum, titanium, fiberglass, graphite, vanadium and others.

I have chosen a lightweight material such as vanadium to construct the inner core or mandrel 1. Vanadium at this time is the lightest weight chrome steel material available for a golf shaft today. Its overall lightness and resistance to torque, or twisting of rotational forces, is the material of choice. Lightweight chrome vanadium is approximately 27% lighter than a carbon steel shaft and one which surpasses the durability and performance characteristics of most composite shafts. Its durability and torque resistance are comparable to much heavier steel shafts. A shaft with this combination will offer optimum consistency in performance by tightly controlling the weight, flex point, wall thickness, balance point, within each shaft/club or set of clubs. Shafts could be designed with steps if desired. Of course, I could choose to use another lightweight steel material or vary the configuration of the mandrel or inner core for different desired results. The criteria can be met by metal alloys after heat treatment, a yield strength equal to or greater than 220,000 IbsJinch. Metal currently acceptable would be AISI 6150 alloy steel. It may be desirable to design a steel/composite combination design that dampens vibration like a graphite shaft and is frequently matched through electronic calibration. When testing players with my patent pending "Precise Fit Golf Club Fitting System", I have found different torque values can have a positive and or a negative influence on the final shaft selection for the player. Composite shafts come in a wide variety of torque ranges or values. Therefore, different torque, stiffness, and flex or kick point values designed into the shaft need to be considered for future development. Torque is usually defined as the twisting or rotational forces exerted on the shaft during the loading and unloading of the club during the swing.

The asymmetrical interlocked wind process or braided process is claimed and marketed by FM Precision to be the lightest composite seamless shaft on the market today. They market this shaft under the brand name "Fibrematrix" and/or Sabre. FM Precision currently markets the UCV 2000 lightweight steel shaft and is available on the market today. Factors such as club length, swing weight, hosel length and insertion depth are not a problem when combining the two materials disclosed herein for my invention. Using an aerospace process employed called Resin Transfer Molding (RTM) by FM Precision will produce a net sized or finished shaft requiring minimal sanding or grinding to achieve the final profile. A combination of two materials i.e., lightweight vanadium steel as the mandrel or inner core, and covering or molding the outer layer with an asymmetrical interlocked winding or braided process, will reduce the overall weight of the shaft to offer the best advantages of steel and composite materials together in a combination that has not existed by prior or current art. It will allow, along with the playing characteristics of steel the lightweightness of graphite and the like composite shafts currently offered, shafts currently exist in low, mid and high flex choices, and other variations in variable stiffnesses and shaft diameters. My shaft invention constructions are clearly applicable to prior and current art golf shafts. Shaft Table 1 below are examples of steel, composite/graphite and Vanadium weights as they are listed in catalogues for marketing. They are meant as examples only. The table illustrates average weights of shafts available on the market at this time. It illustrates by current production standards that it is necessary to increase the nominal as well as the overall gram weight stiffness of the shaft as it increases. Steel has heavier weights than composite by the illustration:

Bend Gram

Type Woods Irons Flex Tip Butt Lenαt Weiα t Point

FM PRECISION X L .335 .560 44" 95g Low

UCV 2000 X R,S .335 .600 45" 96g Mid

Lightweight Steel X L .370 .560 39" 94g Low

X R.S 370 600 40" 95α Mid

PARAGON

Parasonic X R .335 .600 45" 88g Mid Graphite with X S .335 .600 45" 92g Mid Boron Reinforcement X R .370 .600 39" 83g Mid X s 370 600 39" 88q Mid

TRUE TEMPER Dynamic Gold X R200 .335 .600 45" 119g High Steel X R300 .335 .600 45" 122g High X R400 .335 .600 45" 126g High

X R200 .370 .600 40" 120g High X R300 .370 .600 40" 124g High

X R400 370 600 40" 127α Hiαh

Table II: example of FM Precision "Sabre" with their interlocked winding process

Model Butt Tip Nominal Weight^*

No Flex Dia In Dia In Grams Ounces

WFX A .600 .335 74.5 2.63

WFX R .600 .335 80.5 2.84

WFX S .600 .335 82.5 2.91

WFX X .600 .335 86.5 3.05

WFX XX .600 .335 88 3.10

The braided process is the lightest of all graphite or composite shafts. The "Nominal Grams" column above demonstrates current production weight standards. It is necessary to increase the nominal gram weight and the overall weight as the stiffness of the shaft increases. This is in part due to the additional reinforcing needed to make the shaft perform. Producing composite shafts in different stiffnesses with higher kick or flex points creates an additional cost in production. By today standards, the "Sabre" has nominal gram weight of 74.5 grams in the A flex, the R stiffness weighs a nominal gram weight of 80.5, the S stiffness weights a nominal gram weight of 82.5, X (extra stiff) equals 86.5 and the XX (extra, extra stiff) weighs a nominal gram weight of 88.0.

By combining two unlike materials together to form a combination shaft with the consistency of steel and the lightness of composite/graphite, I have invented a new and novel shaft construction. For the mandrel and inner core, I have chosen vanadium because of its resistance to the forces shafts are subject to. Although titanium is an option, through discovery an even lighter alloy material could become available for the mandrel or inner core. The metal alloy after heat treatment must have a "yield strength" equal to or greater than 220,000 lbs./in., with an "ultimate strength" equal to or greater than 240,000 IbsJin. and a test criteria of at least 10 lbs. at any point along the shaft. It may be necessary within and through the inventive process to make adjustments and additions to the forming and finishing of the original designed shaft tube of standard weight because of the tubes thin wall and the higher strength of the material needed, such an alloy is AISI 6150. By combining two unlike materials, the mandrel or inner core would be reduced proportionately in relationship to the overall weight of the entire shaft, whereas strength and piayability when adding or combining the outer covering or braided process would enhance the shaft. Depending on the final thickness chosen, after testing, for the mandrel, the asymmetrical interlocked winding process could be reduced by one-half it's present finished gram or ounce weights as exist today in finished composite/graphite shafts. The asymmetrical interlocked winding process or braided covering will endow the entire shaft with the additional strength needed to prevent the breaking down or fatigue of some shafts as has occurred in the past. Shafts are subject to vibration, shock, torque, and/or dimensional distortions especially during the loading and unloading of the shaft during the swing. Accordingly, it would be desirable while providing a finish to the surface of the outer part. Articles made from the combination of unlike materials consisting of a mandrel or inner core and the advanced composite materials would provide equally superlative characteristics. It has been recently touted by the recycle industry that the refabrication of filament strands for industrial use has the same lightness properties with additional strength inherent in the new or recycled filament. A desired balance could be struck to compliment both unlike materials to insure they are one adhesive functional product in the combination shaft. Problems associated with the durability of composite/graphite shafts are well documented and the breakage and untimely bending of lightweight shafts occurs form time to time.

By combining two or more unlike materials to achieve the final inventive product, a series of events occur. I have discovered with my inventive patent pending process, "Precise Fit Golf Club Fitting System and Golf Shaft Selection Method and Apparatus" that the flex points (kick point) will be a first priority in the shafts of the future, with stiffness being a second objective. The history of the golf industry has presently centered on the (flex) stiffness values. Until my patent pending process, to accurately measure the performance of the shaft in relationship to a golfer/player was discovered, the golf industry could only repeat their past misconceptions. Until flex stiffness as marketed by the industry becomes secondary to the flex point or kick points, confusion in the public mind will continue. For that reason I may choose to refer to kick or flex points as "Predetermined Defined Give Points" or PDG's. Secondly, a shaft with the consistency of steel and the lightness of composite/graphite is needed to enhance the players/golfers abilities. This invention will establish standards between steel and composite/graphite that will allow the industry to develop new shafts that are functional and not just another creation. Finally, a new series of shafts that are designed for piayability based on my patent pending process are needed and should be developed in the future. I have been able to document that steel shafts offered in new clubs for 1998 were offered in the same basic form in most major brands in 1950, 1954 and 1957. Thus, they are not new shafts, but old shafts sold at a new time.

Thus, it is apparent that there has been provided, in accordance with the disclosed invention, a novel golf shaft that satisfies the objective, aims and advantages, as set forth above. While the invention methods and product have been described in competition with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those of ordinary skill in the art, in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations which fall within the spirit and scope of the appended claims.

Claims

PATENT CLAIMS

1. A golf shaft comprised of an inner core member made of steel and the like, and an outer member made of a composite material which covers said inner core, said shaft members being combined to provide a golf shaft having the consistency and durability of performance of a conventional steel golf shaft and the iightweightness of a conventional composite golf shaft.

2. A golf shaft as defined in claim 1 , wherein the said inner core member is made of a lightweight steel material such as vanadium.

3. A golf shaft as defined in claim 1 , wherein said outer member is made of a composite material made by an asymmetrical interlocked winding (braided) process.

4. A golf shaft as defined in claim 1 , wherein the said inner core member is made of a lightweight chrome steel material.

5. A golf shaft having a stiffness value and a flex choice value, said golf shaft being comprised of two unlike types of golf shaft materials which together provide the consistency, strength and durable characteristics of a conventional steel golf shaft, and the Iightweightness of a conventional composite golf shaft.

6. A golf shaft as defined in claim 5, wherein said golf shaft comprises an inner (core) member made of one material and an outer member covering said inner member and made of material unlike the material of said inner member.

7. A golf shaft as defined in claim 6, wherein said inner (core) member is made of a lightweight steel material and said outer member is made of a composite material such as graphite and the like.

8. A golf shaft as defined in claim 5, wherein said inner core is made of aluminum.

9. A golf shaft as defined in claim 5, wherein said inner core is made of titanium.

10. A golf shaft as defined in claim 7, wherein said outer core is made of fiberglass.

11. A method of making a golf shaft having a stiffness value and a flex choice value, comprising the steps of: a) forming an inner core member of lightweight steel material and the like; and b) forming an outer member covering said inner member and made of a composite material, to provide a golf shaft having the consistency and durability of performance of a conventional steel golf shaft and the Iightweightness of a conventional composite golf shaft.

12. A method as defined in claim 11 , further including the step of forming said inner member of vanadium.

13. A method as defined in claim 12, further including forming said composite material outer member by an asymmetrical interlocked winding (braided) process.