Patent Application
20090318245
1. Field of Invention
This invention relates generally to golf clubs and more particularly to the improvement of the driver head and fairway metal head.
2. Description of Prior Art
Conventional golf clubs especially drivers have been improved to maximize flying distances by increasing repulsive power of driver's striking face. Early efforts have lead to thin head faces with supporting structures (U.S. Pat. No. 5,776,001) to prevent breakage. Lately, more advanced structures such as volcano or convex like shapes (U.S. Pat. No. 5,830,084, U.S. Pat. No. 5,954,596 or U.S. Pat. No. 7,338,338 B2) with thick center portions and thin peripheral portions have been developed to increase repulsive power without breakage from high ball contact stress.
Even though the recent improvements described prevent breakage of the sweet spot area, these kinds of structures suffer from having the weight in the center face which result in a smaller MOI, and having a fragile peripheral region near the boundary of the face. Consequently, sometimes breakage of the driver face occurs as the driver strikes a ball outside of the sweet spot.
This invention was thought out to solve the problems mentioned above. Based on the impact mechanics, as the driver head face impacts the golf ball, the impact area absorbs shock energy and stores it by flexing backward at the moment of impact. The flexed driver head face improves energy transfer efficiency to the golf ball. Additionally, the flex of the driver head face results in a lower peak stress. By achieving this driver head face flex without substantial thinning of the sweet spot periphery, the proposed invention avoids the breakage issues associated with previous designs.
At ball impact, significant bending stresses are imparted to the club head face due to the kinetic energy transfer (E=mv2/2 where m is the mass of the head and v is the speed of the head). If the stress of impact exceeds the material limits, the club head face or adjacent area can crack.
In most cases, microscopic observation shows that this cracking phenomenon of the of the face plate is triggered by the separation of the inner metal surface. The cracking phenomenon is due the impact stresses exceeding the allowable stresses of the inner surface of the faceplate. Breakage of the body (shell) can also occur as the ball hits the adjacent area to the body. In this case, impact energy cannot be absorbed and most impact energy is concentrated upon the body part near the hitting area.
This invention provides a golf club having improved ball flight distances with relatively lower breakage rate of the club head. This is achieved by adding a groove as a shock absorbing device on the body part adjacent to the hitting area and constructing several donut or spiral shaped ripples on the inner surface of the face plate of hitting surface.
To achieve the goal mentioned above, the head of the golf club must have shell type construction which is composed of a hitting area and a body area which includes a groove and a hosel that is connected to a shaft.
Conventionally, the face of the club head absorbs impact energy at the moment of impact against the golf ball and the face is bent in the opposite direction of the club head's movement. However, with the proposed structure, which has a slightly larger inner surface of a face plate than conventional structures, the stress diverges very fast through the thin and thick parts formed alternately as concentric rings (or ellipses). Consequently, regardless of the impact spot of the face, the stress per unit area is lower than that of conventional drivers and thus lowers the brakeage rate of the driver head.
Due to improved repellant power by the thin parts of the ripples (valley) and the raised maximum impact strength of the thick part of the ripples (peak), the club head has increased the driving distances with a lower breakage rate compared to the conventional designs. Also, the groove adjacent to the face works as a shock absorber and absorb the impact energy when the impact occurs on the peripheral region of the face.
The first embodiment of this invention illustrated as in
The groove 5 on the body part 1 starts right next from the hosel 3, stretched along the top 7 of the body part 1 and continues all the way to the opposite side of the hosel 3. The cross section of the groove 5 has a half cylinder shape.
The first embodiment of the inner surface of the face plate of hitting area is formed with oval shaped lines of peaks 22, 24, 26 and valleys 21, 23, 25, 27 which are as illustrated in
With a detailed description, the thickness D21 of the valley 21 is thicker than the thickness D23 of the valley 23, the thickness D23 of the valley 23 is thicker than the thickness D25 of the valley 25 and the thickness D25 of the valley 25 is thicker than the thickness D27 of the valley 27. Also, the height D22 of the peak 22 is higher than the height D24 of 24 and the height D24 of the peak 24 is higher than the height D26 of the peak 26.
These peaks 22, 24, 26 and valleys 21, 23, 25, 27 are connected smoothly such as sign or cosine type waves with no sharp edges.
As illustrated in
Similarly the valley 40 at the center of the inner surface 20 is lined smoothly with the valley 41 on the peripheral of the inner face and the thickness D40 of the valley 40 at the center of the inner face 20 is the thickest and the thickness D41 of the valley 41 on the peripheral of the face is the thinnest among The thickness of the valley 40 becomes shallower gradually meeting the valley 41 smoothly where the peak 31 ends.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2008-0059865 | Jun 2008 | KR | national |
