GB2347099A

GB2347099A - Golf club head fabrication method

Info

Publication number: GB2347099A
Application number: GB9904394A
Authority: GB
Inventors: Jung Ming Liu
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-02-25
Filing date: 1999-02-25
Publication date: 2000-08-30
Anticipated expiration: 2019-02-25
Also published as: GB2347099B; GB9904394D0

Abstract

A golf club head fabrication method in which the face panel is fabricated by: preparing two metal plates 1,2 of different shock resistance, then bonding the two metal plates together by means of the use of an explosive through an explosion bonding process, permitting the metal plate of higher shock resistance to be formed into an inner layer of the face panel and the metal plate of lower shock resistance to be formed into the outer layer of the face panel for hitting the ball.

Description

GOLF CLUB HEAD FABRICATION METHOD BACKGROUND OF THE INVENTION The present invention relates to a golf club head fabrication method, and more particularly to such a golf club head fabrication method which fastens clad metals into a face panel for a golf club head by explosion bonding.

In recent years, the game of golf has become more and more popular. It is well known that the quality of the club head of a golf club greatly affects the performance in the game of golf. A good quality of golf club enables the ball to be hit farther without producing much reactive vibration. A variety of materials including aluminum alloy, stainless steel, titanium, titanium alloy, copper, copper alloy, synthetic resin, etc., have been developed and used in the fabrication of golf clubs, and rubber is commonly used for making a golf ball. Further, when two objects hit against each other, a pair of equal ultrasonic pressure waves are produced in reversed directions, and these ultrasonic pressure waves are called shock waves. The pressure of a substance increases from a normal pressure value to P value, and the mass point of the substance is changed from a standing condition to velocity Up (mass velocity). The relationship between P and Up of a substance can be measured through tests, and the interrupted P-Up points of status can be linked into a curve called Hugoniot Curve.

Figure is a chart of Hugoniot Curves obtained from different materials in which al: stainless steel, a2: copper, a3: titanium, a4: aluminum alloy, a5: plastics, a6: hard rubber ball. The shock resistance value is directly proportional to the slope of the curve (the maximum is al stainless steel). At the moment when the club head hits the ball at velocity Uf, the club head and the ball are united together, and moved together at velocity Uc, and at the same time a pair of equal impact pressure are produced in reversed directions in the club head and the ball, causing the ball to be driven away from the club head. The reversed impact pressure which enters the club head is then transmitted through the shaft of the golf club to the user's hands, causing the user feels uncomfortable.

The curve a6 shown in Figure 1 is a hugoniot curved obtained from a hard rubber ball (golf ball) which intersects with the other hugoniot curves. The longitudinal axes of the intersected points represent the respective impact pressure P values of the respective materials, and the corresponding transverse axes represent the respective Uc values. Therefore, the impact pressure is relatively greater when the shock resistance of the club head material is relatively higher. In Figure 1, the shock resistance of stainless steel and copper are the maximum, and the shock resistance of the other materials (titanium, aluminum alloy, plastics) are relatively reduced in proper order. From the aforesaid statement, stainless steel and copper are the best materials for the face panel when only considering the flying ability of the ball, titanium is the second choice, aluminum alloy is the third choice, and plastics is the worst material for the face panel. However, when a high impact pressure is obtained, a high reactive shock is relatively produced. Therefore, when improving the hitting effect, the uncomfortableness from a high reactive shock becomes inevitable. It is really difficult to make up one's mind as to which of two conflicted measures to choose.

SUMMARY OE THE INVENTION The present invention provides a golf club head fabrication method which greatly improves the hitting performance of the golf club head, and simultaneously reduces its reactive shock. Before describing the technical measures of the present invention, the distribution of impact pressure waves in a media should be explained first. When a pressure wave passes from a first media to a second media, a reflex is produced between the interfaces of the two medium due to a shock resistance difference, and the intensity of the reflex is directly proportional to the shock resistance difference between the two medium. If the shock resistance of the first medium is smaller than the second medium, the reflex is the pressure wave, and the internal pressure of the first medium is enhanced by the reflected wave, and therefore the second medium is capable of returning the energy of the pressure wave to the first medium to enhance its pressure energy. On the contrary, if the shock resistance of the first medium is greater than the second medium, the reflected wave is a relaxation wave, and high pressure is released when the relaxation wave reaches, and therefore the second medium is capable of releasing the pressure energy of the first medium. Further, when a pair of impact pressure's produced upon hitting of the golf club head against the ball, the pressure which enters the ball accelerates the motion of the ball, and the ball flies farther when the acceleration time is relatively prolonged. The reversed pressure which enters the metal club head immediately reaches the air interface at the back side of the face panel of the golf club head, causing a reflection.

Because the shock resistance of metal is higher than air, the reflected wave is a relaxation wave, and the accelerating pressure in the ball is released to stop the accelerating action when the relaxation wave enters the ball. Therefore, if the wall thickness of the metal face panel of a golf club head is too thin, the relaxation wave enters the ball immediately after its production, causing the ball unable to fly far due to a short accelerating time. In order to eliminate this problem, the wall thickness of the face panel must be made not thinner than 3mm. In order to prevent the relaxation wave from entering the ball early, two or more clad metals are bonded into a face panel by explosion bonding. When the face panel hits the ball and a reflected wave is produced, the reflected wave must be a pressure wave because the shock resistance of the reflecting medium is greater than the incident medium. Normally, the impact contact time between the club head and the ball is as long as 2llsec, the reflected wave can enter the ball in time to extend the accelerating time, causing the ball to fly farther, and at the same time the interface reflex intercepts the reversed pressure, preventing it from entering the body of the player. If the metals for the face panel are not well bonded together, the reflected wave become a relaxation wave, which shortens the accelerating time of the ball, and reduces the hitting effect of the golf club head.

Because an explosion bonding process is employed to bond clad metals together, the raw face panel thus obtained can receive cutting, bending, forging, heat treatment, any of a variety of processing processes without causing a breaking between layers.

BRIEF DESCRIPTION OF THE DRAWINGS Figure I illustrates hugoniot curves obtained from different golf club heads of different materials.

Figure 2 is a clad metal combination chart according to the present invention.

Figure 3 is a golf club head manufacturing flow chart according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to Figures 2 and 3, a first metal plate 1 and a second metal plate 2 are prepared, and then bonded together. by means of the use of an explosive 3 through an explosion bonding process. The two-layer metal plate thus obtained is then stamped into the desired shape and size, and then processed through a heat treatment to increase its hardness, and then finished into the desired face panel. The shock resistance of the first metal plate 1 is higher than the second metal plate 2. The wall thickness of the first metal plate 1 as well as the second metal plate 2 can be within about 1. 5mm-4mm, however the combined wall thickness of the bonded two-layer metal plate must be controlled within about 3-6mu. The first metal plate 1 can be obtained from stainless steel, copper, titanium. The second metal plate 2 can be obtained from titanium or aluminum alloy. If the first metal plate 1 is obtained from stainless steel or copper, the second metal plate 2 should be obtained from titanium or aluminum alloy. If the first metal plate 1 is obtained from titanium, the second metal plate 2 should be obtained from aluminum alloy.

When the explosive 3 is exploded, a high pressure is produced, causing the surfaces of the first metal plate 1 and the second metal plate 2 to be bonded together. This bonding process eliminates the occurrence of molecular heat diffusion. Because the oxidized layers of the metal plates 1,2 are broken, the bonding area between the metal plates 1,2 has excellent heat and electricity conductive power.

The face panel thus obtained is then welded with a bottom panel 41 to a casing 4, permitting the first metal plate 1 of the face panel to be disposed on the inside and the second metal plate 2 on the outside. Then, the raw golf club head thus obtained is processed into a finished golf club head through a finishing process.

When the finished golf club head hits a golf ball, a pair of equal impact pressure are produced in reversed directions and respectively guided into the golf club head and the ball. The impact pressure which enters the ball drives the ball to fly. The impact pressure which enters the face panel of the golf club head causes a pressure reflection at the first metal plate 1, therefore less shock is transmitted through the golf club head to the user's hands.

As indicated above, the face panel of the golf club head is comprised of two metal layers of different shock resistance bonded together. Because the shock resistance of the first metal plate (inner layer) of the face panel is greater than the second metal plate (outer layer) of the face panel, the reflex which is produced in the golf club head upon striking of the face panel against the ball intercepts the reversed pressure, preventing it from passing to the body of the player.

It is to be understood that the drawings are designed for purposes of illustration only, and are not intended as a definition of the limits and scope of the invention disclosed. For example, more than two layers of metals of different shock resistance can be bonded into a multi-layer face panel through an explosion bonding process.

Claims

What the invention claimed is: 1. A golf club head fabrication method comprising the steps of (a) preparing a metal face panel, (b) preparing a metal casing and a metal bottom panel, (c) welding said metal face panel, said metal casing and said metal bottom panel into a raw golf club head, and (d) finishing said raw golf club head into a finished golf club head, wherein the step of preparing a metal face panel comprises the sub-steps of (i) preparing two metal plates of different shock resistance, (ii) bonding said two metal plates together by means of the use of an explosive through an explosion bonding process, permitting the metal plate of higher shock resistance to be formed into an inner layer of the face panel and the metal plate of lower shock resistance to be formed into the outer layer of the face panel for hitting the ball.
2. The golf club head fabrication method of claim 1 wherein said two metal plates for said face panel each preferably have a wall thickness within about 1. 5mm-4mm.
3. The golf club head fabrication method of claim 1 wherein said face panel preferably has a wall thickness within about 3mm-6mm.
4. The golf club head fabrication method of claim 1 wherein the metal plate for the inner layer of the face panel is a counterweight that adjusts the center of gravity of the golf club head subject to its wall thickness.
5. A golf club head fabrication method substantially as hereinbefore described with reference to and as shown in the accompanying drawings.