GB2308549A - Matched golf clubs - Google Patents

Description

MATCHING OF GOLF CLUBS This invention relates to a method of matching golf clubs in sets, and in particular relates to method for the precision matching of a set of clubs for a player of a particular physique.

The game of golf is now well established worldwide and its popularity is still growing. Essentially in the game of golf the player uses clubs to try to propel a golf ball the prescribed distances according to the design of the club.

Such distances depend not only on the force with which the ball is struck but also on the loft angle of the blade (club head).

By increasing the loft angle of the club, the trajectory of the ball is made higher and the distance travelled less.

Although the golf equipment market offers a multiplicity of designs of club heads as supplied by different makers, individual weights, comparing one make with another, differ very little. In this specification, to avoid complication, only iron clubs are referred to as they form the greater part of the golfer's equipment, but generally the invention will also apply to the clubs known as "woods". Taking any set of iron golf clubs at random, the difference in weight, going from the long No. 2 iron to the short lofted no. 10 iron, increases from club to club, usually progressively by about 7 grams.

The no. 2 head, for example, may weigh 236 grams and the no 10 may weigh 292 grams. The more lofted clubs are heavier because the blades must be widened to ensure that the blade stays in contact with the ball during the stroke and does not slide underneath. (There is a no. 1 long iron, but as it is rarely used by amateur players, it is excluded here.) It should now be explained what is meant by matching as applied to a set of golf clubs of different weights. When discussing shafts, only steel shafts are considered as other materials, such as graphite for example, are not yet universally accepted.

The steel shaft of a golf club is designed to be flexible and to bend when the club is swung in the act of striking a golf ball. There is now a great variety of shafts available and a wide range of flexibilities to suit the physical capabilities of players. Generally strong players require the stiffer shafts.

The bending of the golf club shaft, as the club is swung, stores up energy in the shaft which is intended to be released when contact with the ball is made. With any golf club properly matched to the power capabilities of the player, at the moment of contact between club and ball, the loft angle of the club should take up its natural position. This is illustrated in figure 2 of the accompanying drawings, where the effects of different degrees of flexibility are shown.

In figure 2, condition 'A' illustrates the effect of incomplete release of stored energy in the bent shaft where the shaft is too stiff for the power of which the player is capable of supplying in the swing. The club head lags, the loft angle is negatived, and the full velocity potential is not reached.

Club and player are not matched.

Figure 2'B' shows the opposite condition, where the shaft is too flexible for the power supplied by the player. Here the loft angle is increased, and some velocity is lost. Also the trajectory may be too high or the ball may be struck by the bottom of the blade, resulting in either a skied of fluffed shot. Here the stored energy in the shaft has been released before the club head has reached the hitting position. Again club and player are not matched.

Figure 2'C' is correct and shows complete release of club head energy at contact point, full velocity and correct loft positioning. This is the result of correct matching of club and player's physique, and is a constant objective. As this condition must be obtained with club heads of different weights, it means that some adjustment has to be made in order to compensate for differences in weight.

Currently, in golf club manufacture, in order to achieve this, it is the practice to cut a portion from the tip or small end of the shaft and this is called "trimming". This is done in inch increments so that if the long no. 2 iron tip is shortened by inch, the no. 3 will be shortened by 1 inch, no.

4 by 1.5 inches, and so on. The more that is cut off the tip, the stiffer the shaft becomes.

I have surprisingly found that this inch incremental system is only a crude approximation and is unrelated to the needs of weight compensation accurately to match a set of clubs to a player.

The invention seeks to provide a method of matching golf clubs in sets to a player wherein the correct relative flexibility is maintained from long to short irons.

According to the present invention there is provided a method of matching golf clubs which comprises ascertaining the degree of flexibility needed for one club by reference to the players physique and ability, and producing the remaining clubs in the set by cutting an amount from the tip such as to preserve the correct relative flexibility and removing any further amount needed to produce the correct overall length from the butt end.

The one club used as a test or sample, may be any club in the set, but for convenience will normally be the longest club, e.g. the no. 2 iron. Successively shorter irons will have amounts trimmed from their tips typically less than the heretofore standard e inch.

The overall lengths of clubs differ, each succeeding club in a set, from long to short, being usually inch shorter than the preceding one. Again, the selection a inch increment seems to have no reasonable basis and in fact works against, rather than for, the objective of proper matching. In particular it means that the player must bend the knees more and alter the stance in order to use the over-shortened lofted clubs.

In the method of the invention, established designs in club heads, including weights and lie angles, are employed because moulds for the manufacture of heads represent a considerable investment. Iron club heads are now available in a great variety of designs but weights between one make and another hardly differ. These weights usually range from 236 grams for the longest irons, to 292 grams for the short clubs, weights increasing from club head to club head usually by 7 grams as already stated. Heads may be ordered by the club maker with angles of lie to suit either flat, natural, or upright swings as most easily fits the action of the player, and thickness of grip may also be adjusted to suit large or small hands.

Now consider what happens when a prospective customer tries to purchase a set of golf clubs in a professional's shop, or sports shop. He or she will be presented with a bewildering but beautiful array of clubs of different makes but all designed notionally to suit the model of average physique in three classes: men, women and juniors. Between one make and another, sets of clubs will be almost identical in weight and length of corresponding clubs, and differences are likely to be mainly cosmetic. This means that for anyone who is significantly taller, shorter, stronger or weaker than the popular model, the clubs do not suit and an immediate handicap is acquired. This is in addition to the fact, already mentioned, that standard sets of made-up golf clubs of any make, are not properly matched within the set.

Clubs can be custom made but they still suffer from the defects referred to above. Nowadays electronic machines can be used to measure not only the distance a player can drive a ball but also the direction taken and, in the process, detect other technical faults in performance. The test is usually carried out with a club selected notionally to suit the player. From the information obtained, the shaft, head and grip are determined and a set of clubs is made for the player. In constructing the set however, the e inch incremental system is used. As discussed above, this is purely rule of thumb and has no scientific justification. That is to say that, as a means of compensating for differing weights of club heads in a set, the object of matching, it fails completely.

Because of this, if, from electronic or other test, the sample club has proved satisfactory, then the clubs longer than the sample will be too flexible, and the clubs shorter than the sample will be too stiff. There is therefore, no system at present in existence, capable of matching a complete set of golf irons with any semblance of precision.

The method of the present invention described herein is the result of years of practical experimentation during which theories have been well tested and proven. The object has been to devise a system which, for any power source (capacity of player), can ensure that, with every club in the bag, the ball is met with unaltered stance, maximum velocity, and with the degree of loft for which each club was designed.

The method requires a precise assessment of how much shaft adjustment is needed to compensate for differences in head weights, and the arrangement of overall club lengths which permits the club to meet the ball with unaltered stance. For example, some players requiring very flexible shafts may need no trimming of the tip whatever; with others it could be a progressive trimming advancing on each club by only a few millimetres. Similarly, the shaft lengths may increase from club to club within a set by amounts in the range of, for example, only 5 to 12 millimetres depending on the height of the player, rather than than the standard e inch (12.7mm) almost universally used at present.

Those who have played the game of golf, at any stage amateur or professional, know that the actions of the human body and its members cannot always be under complete control, and that performance can at times be inexplicably erratic. This makes it all the more important that the equipment used should avoid contributing to this condition by being unsuitable and therefore undependable.

Although the importance to the player of matching clubs cannot be overestimated, absolute precision in trying to suit the weight of the club to the player's physique is not so essential. This means that, while it is easily possible to adjust to handling a club heavier or lighter than might be recommended for a particular player, trying to adjust to a set of clubs which are not matched will always be difficult. For this reason it is considered that, for purposes of the method of the invention, physical characteristics require no more than five distinct classifications. Many devices, including electronic, are available for measuring physical characteristics. For those who have not hit a golf ball before, a notional assessment, taking into consideration height, weight, age and muscular development must be made and this can be remarkably accurate.

Regarding driven distances, the following gradings are used hereinafter: over 250 yards, 250/200 yards, 200/160 yards, 160/125 yards, and 125/100 yards. These are considered sufficient to accommodate abilities of players, male or female, from professional class to junior or elderly player. It should be noted that these examples of driven distances provide tolerances of not less than 20%, i.e. 250-200 = 50, 50-250 = 20%. It is found in the practice of applying the method of the invention that this 20% tolerance is sufficient to render the driving test unnecessary. This is because matching, the precise compensating for difference in club head weights, is of such dominating importance that reliance on physical assessment is significantly reduced.

The invention will be described further, by way of example, with refernce to the accompanying drawings, in which: Figure 1 is a diagrammatic side view of a golf club head; Figure 2 'A' to 'C' illustrate shaft flexibilty; Figure 3 illustrates the effect of shaft length; and Figure 4 is a general view of a golf club.

Referring to the drawings, and in particular Figure 4, there are three main parts of a golf club: the head, shaft and grip.

The one mainly capable of permitting adjustment to suit the player is the shaft. Steel shafts are now produced in a great variety of flexibilities by numerous makers. Also it is possible to expand the choice with shafts having low, high or mid bend points. Generally, strong players require stiff shafts with mid or high bend points, the reverse being true for weaker players. Figure 2 'A' shows a shaft too stiff for the player, 'B' a shaft too flexible, and 'C' a shaft of correct flexibility, at impact.

Figure 1 shows the loft angle of a club head, and Figure 3 illustrates, in shadow, the cramped stance of a player with too short a club.

Equipment is available for grading flexibility of a shaft by measuring the extent it will bend with a standard weight attached to the tip of the shaft.

However for the purpose of the invention it is sufficient to arrange shafts, by degree of flexibility, into six groups, the numbers 1 to 6 representing flex factors. These can be immediately related to the power capability of the player as in table 'F' hereunder: Table F Power capability, yards: over 250 250-200 200-160 160-125 125-100 Shaft flex factor 1-2 2-3 3-4 4-5 5-6 In applying the method of the invention, the procedure with any prospective subject would be: Determine physical capacity from details supplied or by visual assessment and height.

Determine flex factor from flex factor scale (see table F).

Determine tip trimming amounts from relevant tables (see tables T1 to T6 hereinafter).

Trim shaft tips as required and fit to club heads.

Select range of lengths corresponding to height (see table L hereinafter).

Cut butt end of shafts to overall lengths as table L.

Assemble shaft and grip to complete.

The procedure in applying the method, taking three specimen subjects, from different categories, will now be described.

Subject 'A' is 6'4" or 193cms tall and on estimate can drive a golf ball 260 yards. The nearest corresponding, flex factor is number 1 (see table F) which is a stiff shaft and, because of the player's height, high bend is recommended.

From table of trimming lengths (T1), the amount to be cut from the shaft for a player 193 cms tall (taking the nearest value, 190 cms) is shown as 33 cms for the longest club, the no. 2 iron. The tip of this club is cut by this much, and the degree of trimming for the other clubs in the set is shown in the same column. All clubs in the set are now trimmed as indicated and club heads fitted.

From tables showing club lengths in relation to height, the figure nearest to the player's height is 190 cms and the corresponding shaft length for the long no. 2 club is 1045 mms.

The butt end of the no. 2 club shaft is then cut to bring the overall club length to this dimension, and the remaining clubs in the set are also cut as shown in the same column. The set of clubs can now be assembled with grips and finished.

Subject 'B' is 5'2" or 157 cms tall and on estimate, can drive a golf ball 185 yards. The flex factor applying is number 3 because the distance is nearer the 200 yard mark. A medium flex, mid bend point shaft is indicated.

The nearest figure on the table, to the player's height is 160 cms, so the trimming amount to be cut from the tip of the no.

2 iron is shown as 15mms and other clubs in the set will require trimming as shown in the column following the figure for the no. 2 club.

From the table 'L', showing club lengths in relation to height, the nearest figure to the player's height of 157 cms is 160 cms, and the length for the no. 2 iron, taken from the table is 976 mms. The shaft of the no. 2 should now be cut to this length, cutting from the butt end, and other clubs in the set treated similarly using the lengths shown in the table after the no. 2 club.

Subject 'C' is 4'7" of 140 cms and on estimate, can drive a golf ball 110 yards. This requires a very flexible shaft and the number 6 low bend point shaft is indicated.

Consulting the trimming table for a player of this height we find that the tip of the no. 2 shaft should be trimmed by only 3 mms. Trimming of other clubs in the set follow, the no. 10 being cut by 27 mms.

Again from the table showing club length in relation to height, it is seen that the no. 2 club length for a player 140 cms tall should be 910 mms, and the butt end of the shaft of the no. 2 club will be cut to this length. Other clubs in the set, nos.

3, 4, 5, etc., should also be cut according to the dimensions in the column following the no. 2. The set can then be completed with grips fitted to shafts.

The trimming tables are compiled from data gathered from experience in testing players of different physiques and abilities. These trimming tables, T1 to T6, together with tables showing club lengths in relation to height, can supply a prescription capable of suiting virtually any physique with matching golf clubs.

Accepting weight differences in a standard set of iron golf clubs as presently marketed, the method of the invention provides: A means of classifying players by physical ability.

A system of arranging lengths of golf clubs precisely correlating club length to height of player.

A system of shaft trimming which ensures compensation for differences in head weights and correct flexing of shaft of each club in a set.

By these means, the invention achieves a precise matching system for players of any ability, meaning that any club in a set, when swung in a golf stroke, should 'feel', in weight, like any other, and with unaltered stance, the player's normal swing should produce the optimum result.

Tables showing amounts to be trimmed from golf club shafts according to height and physique of player: TABLE T1 SHAFT FLEX FACTOR NO. 1 (Stiff, High Bend) Height of player (cms) 200 190 180 170 160 150 140 130 120 Club no. Amounts to be cut from shaft tip (cms) 2 36 33 30 27 34 21 18 15 12 3 37 35 33 30 27 24 21 18 15 4 42 39 36 33 30 27 24 31 18 5 45 42 39 36 33 30 27 24 21 6 48 45 42 39 36 33 30 27 24 7 51 48 45 42 39 36 33 30 27 8 54 51 48 45 42 39 36 33 30 9 57 54 51 48 45 42 39 36 33 10 60 57 54 51 48 45 42 39 36 sand iron 66 63 60 57 54 51 48 45 42 TABLE T2 SHAFT FLEX FACTOR NO. 2 (Stiff, Mid Bend Point) Height of player (cms) 200 190 180 170 160 150 140 130 120 Club no.Amounts to be cut from shaft tip (cms) 2 33 30 27 24 21 18 15 12 9 3 36 33 30 27 24 21 18 15 12 4 39 36 33 30 27 24 31 18 15 5 42 39 36 33 30 27 24 21 18 6 45 42 39 36 33 30 27 24 21 7 48 45 42 39 36 33 30 27 24 8 51 48 45 42 39 36 33 30 27 9 54 51 48 45 42 39 36 33 30 10 57 54 51 48 45 42 39 36 33 sand iron 63 60 57 54 51 48 45 42 39 TABLE T3 SHAFT FLEX FACTOR NO. 3 (Medium, Mid Bend Point) Height of player (cms) 200 190 180 170 160 150 140 130 120 Club no.Amounts to be cut from shaft tip (cms) 2 30 27 24 21 18 15 12 9 6 3 33 30 27 24 21 18 15 12 9 4 36 33 30 27 24 31 18 15 12 5 39 36 33 30 27 24 21 18 15 6 42 39 36 33 30 27 24 21 18 7 45 42 39 36 33 30 27 24 21 8 48 45 42 39 36 33 30 27 24 9 51 48 45 42 39 36 33 30 27 10 54 51 48 45 42 39 36 33 30 sand iron 60 57 54 51 48 45 42 39 36 TABLE T4 SHAFT FLEX FACTOR NO. 4 (Medium mid bend point) Height of player (cms) 200 190 180 170 160 150 140 130 120 Club no.Amounts to be cut from shaft tip (cms) 2 27 24 21 18 15 12 9 6 3 3 30 27 24 21 18 15 12 9 6 4 33 30 27 24 21 18 15 12 9 5 36 33 30 27 24 21 18 15 12 6 39 36 33 30 27 24 21 18 15 7 42 39 36 33 30 27 24 21 18 8 45 42 39 36 33 30 27 24 21 9 48 45 42 39 36 33 30 27 24 10 51 48 45 42 39 36 33 30 27 sand iron 57 54 51 48 45 42 39 36 33 TABLE T5 SHAFT FLEX FACTOR NO. 5 (Flexible mid bend point) Height of player (cms) 200 190 180 170 160 150 140 130 120 Club no.Amounts to be cut from shaft tip (cms) 2 24 21 18 15 12 9 6 3 0 3 27 24 21 18 15 12 9 6 3 4 30 27 24 21 18 15 12 9 6 5 33 30 27 24 21 18 15 12 9 6 36 33 30 27 24 21 18 15 12 7 39 36 33 30 27 24 21 18 15 8 42 39 36 33 30 27 24 21 18 9 45 42 39 36 33 30 27 24 21 10 48 45 42 39 36 33 30 27 24 sand iron 54 51 48 45 42 39 36 33 30 TABLE T6 SHAFT FLEX FACTOR NO. 6 (Flexible low bend) Height of player (cms) 200 190 180 170 160 150 140 130 120 Club no.Amounts to be cut from shaft tip (cms) 2 21 18 15 12 9 6 3 0 0 3 24 21 18 15 12 9 6 3 0 4 27 24 21 18 15 12 9 6 3 5 30 27 24 21 18 15 12 9 6 6 33 30 27 24 21 18 15 12 9 7 36 33 30 27 24 21 18 15 12 8 39 36 33 30 27 24 21 18 15 9 42 39 36 33 30 27 24 21 18 10 45 42 39 36 33 30 27 24 21 sand iron 51 48 45 42 39 36 33 30 27 TABLE L Table of club lengths in relation to height of player (cms) Ratios Length/Height % 53% 55% 57% 59% 61% 63% 65% 67% 69% Height of player (cms) 200 190 180 170 160 150 140 130 120 Club No. Club Lengths in mms 2 1060 1045 1026 1003 976 945 910 871 828 3 1048 1034 1016 994 968 938 904 866 824 4 1036 1023 1006 985 960 921 898 861 820 5 1024 1012 996 976 952 914 892 856 816 6 1012 1001 986 967 944 907 886 851 812 7 1000 990 976 958 936 900 880 846 808 8 988 979 966 949 928 893 874 841 804 9 976 968 956 940 920 886 868 836 800 10 964 957 946 931 912 879 862 831 796 sand iron 940 935 926 913 896 865 850 821 788

Claims (8)

1. CLAIMS 1. A method of matching golf clubs which comprises ascertaining the degree of flexibility needed for one club by reference to the players physique and ability, producing the remaining clubs in the set by cutting an amount from the tip such as to preserve the correct relative flexibility, and removing any further amount needed to produce the correct overall length from the butt end.
2. 2. A method as claimed in claim 1 in which the one club, used as a test or sample, is the longest club, e.g. the no. 2 iron.
3. 3. A method as claimed in either of claims 1 or 2 in which successively shorter irons will have amounts trimmed from their tips typically less than the heretofore standard g inch.
4. 4. A method as claimed in any of the preceding claims in which the shaft lengths increase from club to club within a set by amounts in the range of 5 to 12 millimetres depending on the height of the player.
5. 5. A method as claimed in any of the preceding claims in which players are classified into five groups by physical characteristics
6. 6. A method as claimed in claim 5 wherein, for those who have not hit a golf ball before, a notional assessment, taking into consideration height, weight, age and muscular development is made.
7. 7. A method as claimed in either of claims 5 or 6 in which the five groups represent the ability to drive a golf ball the following distances: over 250 yards, 250/200 yards, 200/160 yards, 160/125 yards, and 125/100 yards.
8. 8. A method substantially as hereinbefore described with reference to the particular description and as illustrated in the accompanying drawings.