GB2247628A - Club head of golf club - Google Patents

Abstract

A club head of a golf club is composed of a club shaft (1), a club head (2) and a grip (3). After high-pressure gas is put into a hollow portion (4) formed inside the club head (2) through a fine hole (5) leading from the surface of the club head to the hollow portion (4). the fine hole is sealed by a stopper (8) so that the high-pressure gas is airtightly contained in the hollow portion (4). Since the inside of the hollow portion (4) is put into a high-pressure state, the restitutive force of a face (6) of the club head is increased and thus the carry of a ball can be increased. <IMAGE>

Description

CLUB HEAD OF GOLF CLUB The present invention relates to the structure of a club head of a golf club.

A golf club is generally requested to be capable of increasing and easily controlling the carry of a ball. In order to increase and control the carry of the ball in the use of a golf club, there have been proposed various kinds of methods, for example, selecting the material of the surface (a face) of a club head, positioning the center of gravity of the club head, balancing the club head and a shaft and improving the restitutive force of the shaft, and the carry is increased and controlled by increasing the initial velocity of the ball while using a compound force produced by appropriately combining these methods.

However, in the above methods, it is extremely difficult to make the carry of the ball longer than the carry obtained by existing golf clubs, and furthermore, to provide golf clubs which match a wide variety of players regardless of age or sex better than the existing ones.

The present invention provides a club head of a golf club capable of increasing the restitution coefficient of a face of the club head by sealing gas of above atmospheric pressure in a hollow portion formed inside the club head so as to increase the carry of a ball.

A club head of a golf club is also provided according to the present invention which is capable of increasing the carry of a ball without increasing the weight of the club head.

A further aspect of the present invention is to provide a club head of a golf club capable of easily increasing the carry of a ball relative to the head speed by adjusting the restitution coefficient of the face of the club head.

A still further aspect of the present invention is to provide a club head of a golf club capable of easily controlling the carry of a ball without increasing the weight of the club head.

The present invention further provides golf clubs which have club heads according to the above descriptions.

Fig. 1 is a front view showing an embodiment of a club head of a golf club to which the present invention is applied; Fig. 2 is a cross-sectional view taken along line II II shown in Fig. 1; Fig. 3 is a front view of a golf club having the club head shown in Fig. 1; and Fig. 4 is a front view showing another embodiment of a club head of a golf club to which the present invention is applied.

Embodiments of the present invention will now be described with reference to the accompanying drawings. The same numerals shown in the drawings denote the same components or corresponding components.

An embodiment of a club head of a golf club to which the present invention is applied will be first explained in conjunction with Figs. 1 to 3.

Referring to Fig. 3, a golf club is formed by fixing a club head 2 at the leading end of a club shaft 1 and mounting a grip 3 at the base end of the club shaft 1.

In the embodiment shown in Figs. 1 to 3, the golf club is an iron and the club head 2 is generally made of metal.

As shown in Figs. 1 and 2, a hollow portion 4 is formed inside the club head 2, and a fine hole 5 leading from the surface of the club head 2 to the hollow portion 4 is formed in a predetermined position (in the upper portion of the club head 2 in this illustrated embodiment) of the club head 2.

A sweet spot 7 (the most suitable point for hitting the ball) is set in almost the center of a face 6 (a plane to hit the ball) of the club head 2.

The hollow portion 4 is disposed in a position including the rear part of the sweet spot 7. The thickness t of the face 6 of the club head 2 can be selected within a range of, for example, 2mm to 6mm, and the thicknesses of other parts can be also set at almost the same as that of the face 6.

According to the present invention, after the hollow portion 4 is filled with gas under high pressure through the fine hole 5, the fine hdle 5 is tightly shut in an airtight state by a proper airtight means 8 which utilizes welding of metal, screwing of a stopper member, pressing and fixing of the stopper member, and so on.

As a filler gas in the hollow portion 4, various kinds of gasses which do not have an adverse influence on the material of the club head 2, such as air or nitrogen, can be used.

The pressure of the filler gas (gas pressure) can be set at, for example, approximately 1-250atm (gauge pressure = relative pressure).

However, since the restitutive force upon the ball can be made greater by increasing the gas pressure, a pressure higher than the above range may be used in accordance with the material of the club head 2 and the head speed so as to increase the carry of the ball.

The volume ratio of the hollow portion 4 filled with the high-pressure gas to a head portion of the club head 2 can be appropriately set in accordance with the type and material of the club head 2 and so on, for example, within a range of 10-95%.

Although the pressure of the above filler gas is generally set at approximately 20atm, if the maximum pressure of the filler gas is set at 200atm, unexpected accidents, for example, breakage of the club head 2 due to excessive pressure in the hollow portion 4, can be prevented by conducting a pressure proof test on the club head 2 while applying a predetermined pressure equal to or more than 250atm into the hollow portion 4, and mounting a relief valve which opens at 200atm in an appropriate position of the club head 2 leading to the hollow portion 4.

The pressure proof test on the club head 2 can be carried out by filling the hollow portion 4 with water and raising the pressure of the water to a test pressure equal to or more than 250atm.

Fig. 4 is a cross-sectional view showing another embodiment of a club head of a golf club to which the present invention is applied and which corresponds to Fig. 2.

In the embodiment shown in Fig. 4, the present invention is applied to a club head of a golf club which is a wood driver for use in a tee shot and so on.

A club head 2 of the driver shown in Fig. 4 can be made of plastic, metal like stainless steel, wood or the like.

A hollow portion 4 is also formed inside the club head 2 shown in Fig. 4 in the same manner as in Fig. 2. A fine hole 5 leading from the head surface to the hollow portion 4 is formed in a predetermined position of the club head 2 (in the upper portion of the club head 2 in the illustrated embodiment). After the hollow portion 4 is filled with highpressure gas, such as high-pressure air or high-pressure nitrogen, through the fine hole 5, the fine hole 5 is tightly sealed by a proper airtight means 8 which utilizes welding of metal, screwing of a stopper member, pressing and fixing of the stopper member and so on, thereby putting the inside of the hollow portion 4 in a high-pressure state.

The hollow portion 4 is also disposed in a position including the rear part of a sweet spot (see the sweet spot 7 shown in Fig. 1) in the embodiment shown in Fig. 4. The thickness t of the face of the club head 2 can be set within a range of, for example, 2mm-6mm, and the thicknesses of other portions can be set at values almost equal to the thickness t.

The pressure of the filler gas (gas pressure) inside the hollow portion 4 can be set at, for example, approximately 1-250atm (gauge pressure = relative pressure). Furthermore, since the restitutive force on the ball can be made greater by increasing the gas pressure, a pressure higher than the above range may be used in consideration of the material of the club head 2 and the gas filling technology so as to increase the carry of the ball.

The volume ratio of the hollow portion 4 filled with the high-pressure gas to the head portion of the club head 2 can be appropriately set in accordance with the type and material of the club head 2 and so on, for example, within a range of 10-95%.

In the embodiment shown in Fig. 4, if the maximum pressure of the filler gas is set at 200atm, unexpected accidents, for example, breakage of the club head 2 due to excessive pressure in the hollow portion 4, can be prevented by conducting a pressure proof test on the club head 2 while applying a predetermined pressure equal to or more than 250atm into the hollow portion 4, and mounting a relief valve which opens at 200atm at a position of the club head 2 leading to the hollow portion 4.

The pressure proof test on the club head 2 may be also carried out by filling the hollow portion 4 with water and raising the pressure of the water to a test pressure equal to or more than 2SOatm.

According to the above-mentioned embodiments, since the hollow portion 4 is formed inside the club head 2 and the inside of the hollow portion 4 is put into a high pressure state by being filled with high-pressure gas, it is possible to rapidly increase the restitutive force of the face 6 of the club head 2 and thus to increase the carry of the ball.

Since the hollow portion 4 is airtightly filled with high-pressure gas, the present invention is suitable for, especially, a metallic club head.

The force F by which the club head 2 having the above structure pushes the ball out is a resultant force of the restitutive force F1 of the face 6 and the restitutive force F2 due to the gas elasticity of the inner high-pressure gas.

The restitutive force F1 of the face 6 is almost determined by the material and the surface state of the face 6 and, in the case of a specific club head, it is constant.

On the other hand, since the restitutive force F2 due to the gas elasticity is determined by a restoring force when a work load stored by the compression of the inner highpressure is emitted, it is directly proportional to the amount of the inner gas pressure.

Therefore, it is possible to set the restitutive force which acts on the ball at the optimum value and thus to increase the carry of the ball by changing the inner gas pressure, or the elastic modulus or the thickness of the club head 2 in accordance with the type of the club head 2 or the head speed.

Furthermore, since the club head 2 is elastically dented in a shot, the side spin can be reduced.

As a result, it is possible to increase the restitutive force F when the face 6 hits the ball and thus to increase the carry of the ball in the same manner as in the above embodiment.

Similarly, the restitutive force F can be changed and the carry of the ball can be controlled by changing the pressure of the high-pressure filler gas.

As described in detail above, according to the present invention, since the hollow portion 4 is formed inside the club head 2 and airtightly contains gas in a high-pressure state, the ball can be pushed out by using the restitutive force due to elasticity of the high-pressure gas inside the hollow portion 4 in addition to the the restitutive force of the face 6 of the club head 2, and furthermore, the push-out force of the ball can be easily changed by changing the pressure of the high-pressure gas. Therefore, it is possible to provide a club head of a golf club capable of easily increasing and controlling the carry of the ball in accordance with the head speed without increasing its own weight.

The present invention can be also applied to club heads of other kinds of golf clubs, such as a baffy, a spoon and a cleek, and can obtain the same advantages as those obtained in the above embodiments.

Claims (11)

CLAIMS:

1. A club head of a golf club wherein a hollow portion is formed inside said club head and airtightly filled with gas under high pressure.

2. A club head according to claim 1, wherein the pressure of said gas is 1~250atom.

3. A club head according to claim 1, wherein the thickness of a face of said club head is 2mm-6mm.

4. A club head according to claim 1, wherein said gas airtightly contained in said hollow portion is air or nitrogen.

5. A club head according to claim 1, wherein said golf club is an iron.

6. A club head according to claim 1, wherein said golf club is a driver.

7. A club head according to claim 1, wherein said golf club is a baffy.

8, A club head according to claim 1, wherein said golf club is a spoon.

9. A club head according to claim 1, wherein said golf club is a cleek.

10. A club head substantially as herein described with reference to and as shown in Figs. 1 to 3 or Fig. 4 of the accompanying drawings.

11. A golf club having a club head according to any one of the preceding claims.