GB2227418A

GB2227418A - A golf set

Info

Publication number: GB2227418A
Application number: GB9001416A
Authority: GB
Inventors: Masanobu Minami
Original assignee: Maruman Golf Co Ltd
Current assignee: Maruman Golf Co Ltd
Priority date: 1989-01-20
Filing date: 1990-01-22
Publication date: 1990-08-01
Also published as: JPH02191473A; JPH0790044B2; GB9001416D0

Abstract

A golf club set comprising a plurality of golf clubs wherein the weight of the shaft of the golf club in the golf club set becomes greater as the length of the shaft becomes shorter, so that it is possible to provide a golf club set in which a longer shaft is relatively soft, and a shorter shaft is relatively stiff. As shown in the figure the thickness 't' of the tube can be increased in a length 'L' and the thickness can be varied along the length thereof for different clubs. <IMAGE>

Description

A GOF CLUB SET BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club set having improved characteristics with regard to the weight and stiffness of the shaft.

2. Description of the Related Arts A golf club set comprises a plurality of golf clubs, and the shafts of all golf clubs in the golf club set are usually made from the same tubular material.

Accordingly, the shafts of the golf clubs in the golf club set all, have an identical thickness of the shaft wall and an identical diameter, and therefore, the weight of the shafts of the golf clubs in the golf club set is proportional to the length of the shafts; the weight becoming lighter as the length of the shaft becomes shorter. Alternatively, sometimes the diameters of the shafts of all of the golf clubs in the golf club set are varied, and in this case, the weight of all of the shafts is made constant.

In this way, in the conventional golf club set, the weight of the shafts is proportional to the length of the shafts, and the weight becomes lighter as the length becomes shorter, and even if the diameter of the shafts is varied, the weight of all of the shafts is made constant. Namely, the weight of the shafts of the golf clubs in the conventional golf club set does not become greater as the length of the shaft becomes shorter.

Also, the shafts of the golf clubs have various stiffnesses, from a relatively soft to relatively stiff.

The stiffness of the golf club as well as the weight of the head of the golf club is an important factor when swinging a golf club, as usually the weight of the head of the golf club becomes lighter as the length of the shaft becomes longer, and becomes heavier as the length of the shaft becomes shorter.

Golfers select golf clubs in consideration of the stiffness of the shaft to suit the individualEg physical strength, and usually a golfer with a relatively weak physical strength tends to select golf clubs with relatively soft shafts. In practice, however, contradictory requirements are set for the stiffness of the shafts in the golf club set. For example, amateur golfers, especially beginners and low handicap players are wary of long distance shots, and a golfer making a shot with a long golf club, for example, a number three iron golf club, tries to swing in such a way that the golf ball will rise and fly far; for this purpose, golf clubs with relatively soft shafts are often adapted.

Conversely, a golfer making a shot with a short golf club, for example, a number nine iron golf club, tries to swing in such a way that the golf ball flies in a relatively straight line of flight, and in this case, golf clubs with relatively stiff shafts are often used.

In the conventional golf club sets, however, it is not possible to satisfy the above described wide range of requirements for the stiffness of the shafts of the long golf clubs and of the short golf clubs.

SUMMARY OF THE INVENTION The object of the present invention is to provide a golf club set comprising a plurality of golf clubs which can satisfy the wide range of requirements for the stiffness of the shafts of the long golf clubs and of the short golf clubs.

Therefore, according to the present invention, there is provided a golf club set comprising a plurality of golf clubs having heads, and shafts attached to the heads respectively, wherein the weight of the shaft of the golf club in the set becomes greater as the length of the shaft becomes shorter.

With this arrangement, the shafts of the golf clubs in the set are made from the same kind of the material, and thus the amount of the material of the shaft per unit length becomes larger and the stiffness becomes greater as the length of the shaft becomes shorter. Therefore, it is possible to obtain a golf club set in which the stiffness of the shaft becomes greater as the length of the shaft becomes shorter, and the stiffness becomes softer as the length of the shaft becomes longer.

In a preferred embodiment, the thickness of the wall of the shaft of the golf club in the set becomes greater as the length of the shaft becomes shorter. In this case, preferably the thickness of the thickened portion becomes greater as the length of the shaft becomes shorter. Alternatively, preferably the length of the thickened portion becomes greater as the length of the shaft becomes shorter. Also, preferably one end portion of the shaft is partially thickened, so that the golf clubs have a greater flexibility at the free end portion of the shaft or at the portion near the grip, as desired.

Further preferably, the diameter of the shaft of the golf club in the set becomes greater as the length of the shaft becomes shorter, and the weight of the shaft of the golf club in the set becomes greater as the length of the shaft becomes shorter.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more apparent from the following description of the preferred embodiment, with reference to the accompanying drawings, in which: Fig. 1 is a schematic view of a golf club set according to the first preferred embodiment of the present invention, with shafts in the set partially shon in section; Figs. 2A to 2E are view of various embodiments having in which the thickness of the walls of the shafts is varied, to change the weight of the shafts; Pig, 3 is a view of an embodiment for changing the diameter of the shafts, to change the weight of the shafts; Figs. 4A to 4C are views of tapered shafts;; Fig. 5 is a view showing the relationship of the weight of the shaft to the length of the shafts of the golf club sets of the present invention and of the prior arts; Fig. 6 is a view showing the weight of the head obtained from the relationship of Fig. 5; Fig. 7 is a view showing the stiffness of the shaft obtained from the relationship of Fig, 5; and Fig. 8 is a view showing the natural frequency obtained from the relationship of Fig. 5.

DESCRIPTXON OF THE PREFERRED EMBODIMENT Figure 1 shows a golf club set S according to the preferred embodiment of the present invention, in which three typical iron golf 'clubs, 113it, 'Si and "9i' are illustrated. Each of the iron golf clubs, "3i", "5i" and "9i" has a head 10, a shaft 12, and a grip 14. The shaft 12 of each of the iron golf clubs, "3i", "ski" and "9i" in this golf club set S is formed of a hollow tube having a length of 11 , 12 , 13 , and a thickness t1 t2 a and t3 of the tubular wall, respectively.A relationship of ii > 12 > 13 exists among the lengths of the shafts in the golf club set S, and according to the present invention, a relationship of t1 < t2 < t3 exists among the thicknesses of the wall of the shafts; the weight of the shaft 12 of the golf clubs, t3i", "5i" and '1ski in the gold club set S becomes greater as the length of the shaft 12 becomes shorter. It should be noted that the golf club set S of course comprises more than three iron golf clubs, and that the other iron golf clubs are not shown Xn Fig. 1, to clarify the description. Also, the golf club set S can include wood type golf clubs as well as iron golf clubs, and in the set of wood type golf clubs, it is possible also to arrange that the weight of the shaft 12 becomes greater as the length of the shaft 12 becomes shorter.

Figures 2A to 2E are views of various embodiments in which the thickness r of the walls of the shafts 12 is varied, to change the weight of the shafts, wherein Fig. 2A shows an example in which each shaft 12 has a constant thickness t along the entire length thereof and a thickness t is varied for every golf club; Figs, 2B to 2E show examples in which a portion 12a of the shaft 12 is partially thickened along the length thereof and the thickness t of the thickened portion 12a becomes greater as the length of the shaft 12 becomes shorter; Figs. 2B and 2C also show that the thickened portion 12a is located at an end portion of the shaft 12 on the side of the head 10; and Figs. 2D and 2E show that the thickened portion 12a is located at an end portion of the shaft 12 on the side of the grip 14.Accordingly, it is possible to provide a variation of stiffnesses of the shaft 12 by partially locating the thickened portion 12a along the length of the shaft 12, so that the golf clubs have a greater flexibility at the free end portion of the shaft 12 or at the portion near the grip 14, as desired.

Also, Figs. 2D and 2E show that not only is the thickened portion 12a provided at an end portion of the shaft 12 on the side of the grip 14 but also the length L of the thickened portion 12a can be varied for each golf club.

Also, Figs. 2B and 2C show that not only is the thickened portion 12a provided at an end portion of the shaft 12 on the side of the head 10 but also the length L of the thickened portion 12a can be varied for each golf club.

Figure 3 is a view of an embodiment of changing the diameter D of the shafts 12, to change the weight of the shafts 12. In this embodiment, the diameter D becomes greater as the length of the shaft 12 becomes shorter, for example, the diameter D3 of the shaft 12 of the number nine iron golf club ilsilt is greater than the diameter D1 of the shaft 12 of the number three iron golf club u3i(. Ir. the set of wood type golf clubs also, it is possible to arrange that the weight of the shaft 12 becomes greater as the length of the shaft 12 becomes shorter. Further, it is possible to combine the change of the diameter D and the change of the thickness t of the wall of the shaft 12, to thereby change the weight of the shaft.

The above described features can be applied to tapered shafts 12, as shown in Figs. 4A to 4C. In Fig. 4A, the tapered shaft 12 is further provided with steps 12b. Figure 4B shows a uniformly tapered shaft 12, and Fig. 4C shows the tapered shaft 12 with a tapered portion 12c and a straight portion 12d. In these tapered shafts 12, it is possible to change the thickness of the wall of the shaft 12 entirely or partially along the length thereof, or to change the diameter of the shaft 12.

Figure 5 is a view showing the relationship of the weight of the shaft to the length of the shaft of the golf clubs in the golf club sets of the present invention and of the prior art. The prior art (A) is plotted by small triangular marks and lines therebetween, and illustrates that the weight of the shaft becomes lighter as the length of the shaft becomes shorter. The prior art (8) is plotted by small cross marks and lines therebetween and illustrates that the weight of the shaft is constant regardless of the length of the shaft. The example of the present invention is plotted by small circular marks and lines therebetween, and illustrates that the weight of the shaft becomes greater as the length of the shaft becomes shorter.

Figure 6 is a view showing the weight of the head obtained from the relationship of Fig. 5, in which the weight of the head is decided so that the same swing force is obtained from a predetermined relationship between the length of the shaft and the weight of the head. The features of the present invention and the prior arts are represented by the same characters as those used in Fig. 5. According to the present invention, and in corrparison to the prior arts, it is possible to reduce an incremental ratio of the weight of the head as the length of the shaft becomes shorter, because the weight of the shaft of the golf club in the set becomes greater as the length of the shaft becomes shorter. That is, the weight of the head of the short shaft according to the present invention is lighter than that of the prior arts.

Figure 7 is a view showing the stiffness of the shaft obtained from the relationship of Fig. 5. The stiffness of the shaft of the present invention becomes stiffer at a greater ratio as the length of the shaft becomes shorter, in comparison to the prior arts, and the difference of the stiffness between the short shaft and the long shaft becomes greater. Therefore, it is possible to make the shafts in the set such that the long shaft is relatively soft and the short shaft is relatively stiff. Also, as shown in Fig. 8, it is possible to obtain golf clubs having a frequency characteristic in which the long shaft has small frequency and the short shaft has a large frequency.

As explained above, according to the present invention, the weight of the shafts of the golf clubs in the set becomes greater as the length of the shaft becomes shorter, so that is is possible to provide a golf club set in which a longer shaft is relatively soft, by which a golf ball can be easily hit high, and a shorter shaft is relatively stiff, by which a golf ball can be hit in a desired direction of flight.

Claims

1. A golf club set comprising a plurality of golf clubs having heads and shafts attached to the heads, respectively, wherein the weight of the shaft of the golf club in the set becomes greater as the length of the shaft becomes shorter.

2. A golf club set according to claim 1, wherein the thickness of the wall of the shaft of the golf club in the set becomes greater as the length of the shaft becomes shorter.

3. A golf club set according to claim 2, wherein the thickness of the wall of the shaft of the golf club in the set is partially thickened along the length thereof and the thickness of the thickened portion becomes greater as the length of the shaft becomes shorter.

4. A golf club set according to claim 2, wherein thickness of wall of the shaft of the golf club in the set is partially thickened along the length thereof and the length of the thickened portion becomes greater as the length of the shaft becomes shorter.

5. A golf club set according to claim 3, wherein one end portion of the shaft is partially thickened.

6. A golf club set according to claim 4, wherein one end portion of the shaft is partially thickened.

7. A golf club set according to claim 1, wherein the diameter of the shaft of the golf club in the set becomes greater as the length of the shaft becomes shorter.