US 20050233829 A1
A putter club having a relatively hard face insert supported by at least one dampening layer is disclosed. The putter club also has an internal weight positioned in line with the center of gravity of the club. The putter club has a body and a sole plate wherein the density of the body is substantially higher than the density of the sole plate. A vibration dampening system for a golf club is also disclosed.
1. A putter comprising a club head having a body comprising a front portion and a back portion, wherein the front portion has an insert supported by a dampening layer and the insert has a Brinell hardness of at least about 150.
2. The putter of
3. The putter of
4. The putter of
5. The putter of
6. The putter of
7. The putter of
8. The putter of
9. The putter of
10. The putter of
11. The putter of
12. The putter of
13. The putter of
14. The putter of
15. The putter of
16. The putter of
17. The putter of
18. The putter of
19. The putter of
20. The putter of
This application is a continuation of co-pending U.S. application Ser. No. 10/704,774, filed Nov. 10, 2003.
This invention generally relates to golf clubs, and more particularly relates to putter golf clubs.
Golf clubs, particularly the clubs used on and around the greens, have long been developed to improve the touch and feel for the golfers. Conventional approaches to improve touch and feel include modifying the grip, the shaft or the strike face of the clubs. In one example, U.S. Pat. No. 6,231,458 B1 discloses an insert on the strike face that affects the rebound of the golf ball at impact with the strike face. The '458 patent further discloses a dampening layer located behind the insert that dampens the vibrations caused by the impact and improves the touch and feel feedback to the golfers. The amount of feedback can be controlled by the amount of contact between the face insert and the dampening layer. To improve touch and feel, the insert is made from a relatively soft tellurium copper alloy.
In another example, U.S. Pat. No. 6,238,303 B1 discloses a putter club having a user-replaceable face insert. The insert is selected to have different weight, texture and hardness. The user can choose a particular insert for the club to match the club's putting characteristics to the green's conditions. The insert can be fabricated from titanium, graphite, polytetrafluoroethylene (PTFE), copper, brass, plastics, aluminum, carbon steel, stainless steel among others.
However, the prior art does not contemplate a putter that has a striking face with properties that are uniquely different from other parts of the club.
Hence, the present invention is directed to a putter club having a face insert.
The present invention is also directed to a putter club having a relatively hard face insert supported by at least one dampening layer.
The present invention is directed to a system of vibration dampeners for a golf club.
The present invention is also directed to a putter club having an internal weight positioned in line with the center of gravity of the club.
The present invention is also directed to a putter club with a body and a sole plate wherein the density of the body is substantially higher than the density of the sole plate.
In the accompanying drawings, which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:
Putter club head 10 in accordance with an embodiment of the present invention is illustrated in
As best shown in
Sole plate 18 is preferably made separate from body 28 and is attached thereto by any conventional means, such as threaded fasteners, as best shown in
In accordance to one aspect of the present invention, weight 30 is positioned at a location directly behind the center of gravity of putter 10. When putter 10 strikes a golf ball at its center of gravity, weight 30 would line up on an imaginary line connecting the center of gravity of the club to the center of gravity of the ball. More preferably, the center of gravity of weight 30 lines up with this imaginary line. In other words, weight 30 is positioned such that it lines up with the center of gravity of the club in the X, Y and Z directions. Such disposition of weight 30 advantageously minimizes vibration when the putter strikes a ball.
In accordance to another aspect of the present invention, preferably disposed between insert 26 and body 28 is a first dampening layer X. Dampening layers in putter golf clubs are fully disclosed in commonly owned U.S. Pat. No. 6,231,458 B1, which is incorporated herein by reference in its entirety. Suitable dampening materials include any materials, such as polymeric materials, that posses the appropriate tangent of delta to absorb vibrations generated by impacts with golf balls and to improve the touch and feel of the club. Optional screws, as illustrated in
A second dampening layer Y can be provided in gap 40 between insert 26 and the rest of face 12 to further dampen vibration. Preferably, the second dampening layer is made from silicone material. Furthermore, a third dampening layer Z can be provided between weight 30 and sole 18, and preferably third dampening layer Z is made from the same material as the first dampening layer.
In accordance to one aspect of the present invention, insert 26 is made from a substance that is relatively hard, i.e., having high hardness measurement. In one example, the insert is made from a grade 303 stainless steel commercially available from Monstanstahl AG of Germany (hereinafter SS 303 DE), and the body is made from other commercial grade 303 annealed stainless steel and the sole plate is made from commercial grade aluminum alloy 6061. The tables below summarize the chemical make-up and mechanical properties of the different parts of club head 10.
Brinell hardness is measured by forcing a hard steel or carbide sphere of a specified diameter under a known applied force for a known duration of time. The Brinell hardness number is obtained by dividing the force of the load used in kilogram by the actual surface area of the indentation caused by the sphere in square millimeters. The Brinell hardness number, therefore, has a unit similar to that of pressure. For aluminum and other soft metals, the applied force used is 500 kg. For the harder irons and steels, the applied force used is 3000 kg. The time period that the force is applied is about 10-15 seconds. Preferably, hardness tests are conducted under the ASTM E-10 standard.
The mechanical properties listed above for stainless steel 303 represent typical properties for stainless steels 303 that have been annealed, and the mechanical properties listed for SS 303 DE are the properties for the stainless steel 303 produced by Monstanstahl AG, which is the preferred material for insert 26. Although insert 26 and body 28 can be made from the same material, e.g., stainless steel 303, insert 26 is softer (lower hardness) but has higher yield strength and tensile strength than body 28.
Two sets of numbers are given for aluminum alloy 6061. The first set corresponds to the annealed alloy and the second set corresponds to the alloy that had been tempered. Both alloys are suitable for sole 18. The annealed aluminum alloy 6061 is more preferred due to its softness for ease of manufacturing. Additionally, aluminum alloy 6061 has a density that is about 3 times less than the density of stainless steel 303, and when used in the sole plate can move the center of gravity of the putter upward to a more desirable position.
The inventor of the present invention believes that a combination of a relatively hard hitting face provided by the hard insert with more than one dampening layer supporting the hard insert provides the putter with better touch and feel.
While it is apparent that the illustrative embodiments of the invention disclosed herein fulfill the objectives stated above, it is appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments, which would come within the spirit and scope of the present invention.