EP2164583A1

EP2164583A1 - Golf putter

Info

Publication number: EP2164583A1
Application number: EP08767092A
Authority: EP
Inventors: Hakan Kronogârd; Bengt Frejd
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-06-29
Filing date: 2008-06-30
Publication date: 2010-03-24
Also published as: US20100331105A1; SE0701586L; SE532442C2; EP2164583A4; WO2009005439A1

Abstract

A putter comprising a shaft and a club head, wherein the club head is a lightweight club head, and the club head has a low center of gravity. The club head has the shape of a U seen from above having two side portions forming the legs in the U-shape and a central portion connecting the side portions and comprising a striking surface for hitting the ball. The club head has a weight of 140 to 230 gram, such as 160 to 220 gram, for example about 200 gram. The center of gravity is positioned a distance above the lowest point of the club head, said distance being 2 to 12 mm, such as 3 to 8 mm, for example about 4 mm. The shaft is attached to the club head with an angle (α) in a direction forward along the target line as seen from the club head and upwards. This angle (α) is 2° to 10°, such as 3° to 8°, for example 4° or 5°.

Description

TITLE: GOLF PUTTER

FIELD OF INVENTION

The present invention relates to a golf putter comprising a lightweight club head.

BACKGROUND OF THE INVENTION

US 6045453 discloses a golf putter/chipper club head, which is generally hammer shaped both in plan view and in cross section and provides for an easily accomplished true pendulum swing by concentrating the mass of the club at the very perimeter of the arc of the pendulum, on-line with the direction of swing. The concentration of club head mass, being very low and directly behind the ball striking area of the club head makes it much easier to get very solid ball contact. A single club using this club head design can be used either right or left handed, even though there is but one ball striking face. By optimizing the club head weight, regulating the length of chips and/or putts essentially becomes an exercise in simply regulating the length of the back swing.

This prior art putter has certain disadvantages. For example, if the ball is hit at a striking point slightly at the side of the optimal ball striking point, the putter has a tendency to become inclined resulting in that the ball direction does not become the intended direction. This is especially true for a lightweight putter.

In addition, the prior art putter has a drawback that the back swing does not become an identical copy of the forward swing, resulting in slightly unpredictable results.

Thus, there is a need in the art for an improved putter of the lightweight type.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to mitigate, alleviate or eliminate one or more of the above-identified deficiencies and disadvantages singly or in any combination. According to an aspect of the invention, there is provided a putter comprising a shaft and a club head, wherein the club head is a light-weight club head, and the club head has a low center of gravity; and the club head has the shape of a U seen from above having two side portions forming the legs in the U-shape and a central portion connecting the side portions and comprising a striking surface for hitting the ball. The club head may have a weight of 140 to 230 gram, such as 160 to 220 gram, for example about 200 gram. The center of gravity may be positioned a distance above the lowest point of the club head, said distance being 2 to 12 mm, such as 3 to 8 mm, for example about 4 mm. In an embodiment, the shaft may be attached to said club head with an angle (α) in a direction forward along the target line as seen from the club head and upwards. The angle (α) may be 2° to 10°, such as 3° to 8°, for example 4° or 5°.

The shaft may be attached to said club head in a position close to a striking surface. Alternatively, the shaft may be attached to said club head in a position remote from a striking surface. The shaft may comprise bends at the bottom portion for forming said angle (α).

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects, features and advantages of the invention will become apparent from the following detailed description of embodiments of the invention with reference to the drawings, in which:

Fig. 1 is a view from above of a club head according to an embodiment of the invention.

Fig. 2 is a view from the front of the club head according to Fig. 1. Fig. 3 is a side view of the club head according to Figs. 1 and 2.

Figs. 4 to 7 are front views of a player performing a conventional putting sequence.

Figs. 8 to 10 are front views of a player performing a putting sequence according to the present invention.

Figs. 11 to 14 are front views of different embodiments of a club head according to the present invention.

Figs. 15 and 16 are front views of a player performing another putting sequence according to the present invention, without a back swing.

Fig. 17 is an enlarged side view of a portion of Fig. 16.

DETAILED DESCRIPTION OF EMBODIMENTS

Below, several embodiments of the invention will be described with references to the drawings. These embodiments are described in illustrating purpose in order to enable a skilled person to carry out the invention and to disclose the best mode. However, such embodiments do not limit the invention. Moreover, other combinations of the different features are possible within the scope of the invention.

Fig. 1 shows a club head for a putter from above. The club head 10 comprises a central portion 11 having a first striking surface 12 intended to hit the golf ball along an intended target line shown by broken lines 15. The central portion comprises a hole 13 for attachment of a putter shaft 14, partially shown in Fig. 1. At each side of the central portion 11, there is attached a side portion 16, 17, so that the head 11 has a U-shape as seen from above. The side portions 16, 17 extend backwards from the central portion. The head has a substantially constant thickness, as appears from Fig. 2, except that the central portion has en enlargement for forming a striking surface 18 for contact with the golf ball. Since the club head has a constant thickness, which is small, the center of gravity is positioned as low as possible. In an embodiment, the central portion has a width of about 17 to 20 mm and a length in the toe-heel direction of 145 mm. Each side portion has a width of 53 mm and a length of about 37 mm. The entire club head has a substantially constant thickness of about 8 mm. However, the central portion and the striking surface has a thickness of about 23 mm. Thus, the center of gravity is positioned about 4 to 5 mm above the lowest point of the club head. The bottom surface of the club head may be slightly rounded.

As appears from Fig. 1, the club head is symmetrical around the target line 15, so that the center of gravity is positioned directly behind the hit intended striking point.

However, often the ball is hit slightly beside the striking point. In this case, the forces will tend to tilt or rotate the club head, resulting in that the ball will not follow the intended target line 15. By arranging the side portions 16, 17 at a distance from the center of gravity, the club head will have a large momentum of inertia, which helps in preventing said tilting of the club head when the ball is hit slightly beside the intended striking point. Thus, a stable club head is obtained by said U-shape.

The club head has a low weight of 140 to 230 gram, such as 160 to 220 gram, for example about 200 gram.

The center of gravity is positioned about 2 to 12 mm above the lowest point, such as 3 to 8 mm, for example about 4 mm.

As appears from Fig. 3, the club head is attached to the shaft at an angle α. The angle is arranged so that the shaft extends forward in the direction of the target line 15 as seen from the club head and upwards.

As appears from Fig. 2, the shaft in addition has an inclination directed towards the player as is conventional. This inclination may normally be about 20 to 30°, but can have any size, and is not part of the present invention.

Figs. 4 to 7 show a typical moving sequence for a conventional putter. As shown in Fig. 4, the player 20 starts with the club head 21 directly below the eyes

22 and in contact with the ball 23.

In a first movement, as shown in Fig. 5, the club head is moved backward over an angle 24 of about 5 to 10°. This rotation takes place around an axis 25, which is positioned close to the wrists of the golfer. The object of this first rotation is to position the wrist of the left arm 26 in a convenient angle position for the following movements, wherein the left arm is almost straight.

In a second movement, as shown in Fig. 6, the club head is moved still further backwards over a distance corresponding to a desired back swing. This second movement is a rotation around another axis 28, which is shown as the left shoulder of the golfer. This is because the left arm has obtained a convenient angular position and no further rotation in the wrist portion is required.

In a third movement, as shown in Fig. 7, the club head is moved back towards the ball in the target direction, in order to hit the ball. Now, the left arm 26 is in a constant angular position, so the entire movement forwards is around the second axis 28. The right arm 27 controls the movement and exerts a sufficient force, together with the left arm, for accelerating the club head. As clearly appears from Fig. 7, in the striking moment, the hands are in another position than in the start position in Fig. 4. This is because of the first movement around the wrist axis 25 for finding the best angular position for the left arm, which then is substantially locked to form a pendulum. However, since the back swing and the forward swing are different, it is difficult to control the entire movement. The forward movement needs to be compensated, and the compensation is often different for different forces. Thus, the result is partly unpredictable, at least for a non-experienced golfer. The forward swing is mainly controlled by the right arm 27, which has the best ability for precision work for a person having right domination. For a left-handed golfer, the tasks of the arms are shifted, as is well known.

According to en embodiment of the present invention, the club head is attached to the shaft with an angle α, which corresponds to the mentioned convenient angle for the left arm. A putting sequence with a club head according to said embodiment is shown in Figs.

8 to 10. The shaft is already in the start position arranged with an angle in relation to the vertical, so that the left arm and the left wrist have obtained said convenient angle already in the start position shown in Fig. 8. Thus, the back swing shown in Fig. 9 involves a rotation around the shoulder axis 28 similar to that shown in Fig. 6. The forward swing follows exactly the same path as the back swing, as shown in Fig. 10. This makes the conditions the best for hitting the golf ball in the desired direction.

As shown in Fig. 8, the club head is normally positioned slightly behind the golf ball 23, which is positioned exactly below the eyes of the golfer. This position is often convenient for the sight procedure. However, the golf ball may be positioned in contact with the club head, or at a larger distance from the club head as shown in Fig. 15.

If the putt is short, it may not be required to have a back swing. Instead, the golfer starts in the position shown in Fig. 15. The left arm is already in the convenient angular position because of the shaft angle α. Then, the club head is moved to the right to hit the golf ball in a forward swing, i.e. without a back swing. The distance between the golf ball in the start position according to Fig. 15 is dependent on the length of the intended putt. A short length, as shown in Fig. 8, results in a short putt and a long length as shown in Fig. 15, results in a longer putt. The length of the putt is dependent on the speed of the club head at the hit moment. In the present embodiment, the club head is a lightweight club head, which can be accelerated to a desired speed at a shorter distance than a more heavy club head. Thus, the alternative putt movement without a back swing may be used even for longer putts. As appears from Fig. 16, the club head moves upwards at the end of a long putt movement. However, a good or clean hit can still be obtained, since the center of gravity is low so that the center of gravity will still be below or adjacent the middle of the golf ball. This is shown more clearly in Fig. 17, which is an enlarged side view of the clubhead and the golf ball in the position shown in Fig. 16. In the figures, it has been indicated that the putt rotates around axis 28 at the left shoulder. This may be different for different golfers. A golfer may instead rotate around a shaft which is somewhere between the right shoulder and the left shoulder, however, at the same height as the axis 28.

Figs. 11 to 14 show different embodiments of a club head having said convenience angle. The embodiment of Fig. 11 is more or less the same as that of Figs. 3 and 8. Different players may have different convenience angles, as defined above. Thus, the angle between the shaft and the club head may be different. An angle between about 2° to 10°, such as 3° to 8°, may be good. Many players would benefit of an angle of 4° or 5°.

Fig. 12 shows another embodiment, in which the shaft is attached to the club head at a position remote from the striking point. Thus, the club head can be positioned close to the golf ball when being positioned opposite the eyes of the golfer. An angle of 5° corresponds to approximately 70 mm, which may be the width of a club head, and is shown in Fig. 12. If an angle of 10° is used, the situation may be as shown in Fig. 13.

A further embodiment is shown in Fig. 14, in which the bottom portion of the club shaft comprises two bends so that the bottom portion of the club shaft extends in the backwards direction. Such an embodiment is allowed according to the golf rules.

Although the present invention has been described above with reference to specific embodiment, it is not intended to be limited to the specific form set forth herein. Rather, the invention is limited only by the accompanying claims and other embodiments than the specific above are equally possible within the scope of these appended claims. In the claims, the term "comprises/comprising" does not exclude the presence of other elements or steps. Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented by e.g. a single unit. Additionally, although individual features may be included in different claims, these may possibly advantageously be combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. In addition, singular references do not exclude a plurality. The terms "a", "an", "first", "second" etc do not preclude a plurality. Reference signs in the claims are provided merely as a clarifying example and shall not be construed as limiting the scope of the claims in any way.

Claims

1. A putter comprising a shaft and a club head, wherein the club head is a lightweight club head; the club head has a low center of gravity; and the club head has the shape of a U seen from above having two side portions forming the legs in the U-shape and a central portion connecting the side portions and comprising a striking surface for hitting the ball.

2. The putter according to claim 1 , wherein said club head has a weight of 140 to 230 gram, such as 160 to 220 gram, for example about 200 gram.

3. The putter according to claim 1 or 2, wherein said center of gravity is positioned a distance above the lowest point of the club head, said distance being 2 to 12 mm, such as 3 to 8 mm, for example about 4 mm.

4. The putter according to any one of the previous claims, wherein said shaft is attached to said club head with an angle (α) in a direction forward along the target line as seen from the club head and upwards.

5. The putter according to claim 4, wherein said angle (α) is 2° to 10°, such as 3° to 8°, for example 4° or 5°.

6. The putter according to claim 4 or 5, wherein said shaft is attached to said club head in a position close to a striking surface.

7. The putter according to claim 4 or 5, wherein said shaft is attached to said club head in a position remote from a striking surface.

8. The putter according to claim 4, 5 or 6, wherein said shaft comprises bends at the bottom portion for forming said angle (α).