Golf putter head

Abstract

A golf putter head includes a front face (1) for striking a golf ball. At least the part of the front face (1) that is intended for striking the ball is defined by a sphere, the centre of which is to the rear of the putter head and, when the putter head is orientated in an upright position appropriate for striking the ball, the centre of the sphere is from 23 to 25 mm above the bottom of the putter head.

Description

The invention relates to a putter for use in playing golf and, more particularly, to a putter head.

A common problem that causes a ball to be struck in a direction away from the target line is that the putter head is turned during the putting stroke so that the front face of the putter head that strikes the golf ball is not perpendicular to the target line at the moment of impact. Such a problem has been known for many years and is referred to as “opening” or “closing” of the putter face. Such opening or closing of the putter face may be due to a “twitching” caused by one hand dominating the other.

A great many designs of putter head are known and a common purpose of such designs is to make it easier for a user to strike a golf ball along a target line. Thus it has been proposed for example to provide a putter head with a wide variety of shapes of front face. Examples of such shapes are shown in WO 9611727, U.S. Pat. No. 3989257, U.S. Pat. No. 5382019 and U.S. Pat. No. 6155933.

In U.S. Pat. No. 6155933, for example, a putter head with a front face defined by a portion of a sphere is disclosed, with the centre of the sphere located behind and below the bottom face of the club head in order to impart a certain amount of lift to the golf ball.

It is an object of the invention to provide a putter head including a front face of especially advantageous shape.

According to the invention there is provided a golf putter head including a front face for striking a golf ball, wherein at least the part of the front face that is intended for striking the ball is defined by a sphere the centre of which is to the rear of the putter head and wherein, when the putter head is orientated in an upright position appropriate for striking the ball, the centre of the sphere is more than 22 mm above the bottom of the putter head.

Since a standard golf ball has a diameter of 42 mm, the putter head of the invention will, when used conventionally, strike the ball above its horizontal diameter. By combining that feature with that of the golf putter head having a spherical front face for striking the ball, it has been found that a significant improvement in putting can be obtained. Although providing such a convex face to a putter head might at first sight seem undesirable especially in relation to ensuring that the part of the putter face that strikes the ball is perpendicular to the target line, it has been found to be of significant advantage. For example, if the opening of the putter face is accompanied by an outward movement of the putter face relative to the target line, then those two effects can cancel out so that the part of the putter face that strikes the ball is perpendicular to the target line. It has also been found that the curving of the face in a vertical direction as defined above is helpful in imparting a degree of top spin to the ball. Thus the particular combination of features defined above have been found to be especially advantageous.

Whilst it is essential only for the part of the front face of the putter head that makes contact with the ball to be spherical, it is preferred that the whole of the front face of the head is defined by the sphere.

The radius of the sphere should not be so great that the face of the putter head is virtually flat and the effect of the invention lost. Equally, if the radius is too small, other undesirable effects are likely to arise during use of the putter head. Usually the radius of the sphere will be in the range of 30 mm to 2000 mm and preferably it is in the range of 100 mm to 1600 mm. In embodiments described below, it is within these ranges.

Preferably, when the putter is orientated in an upright position appropriate for striking the ball, the centre of the sphere is from 23 to 25 mm above the bottom of the putter head.

The golf putter head preferably further includes a hozel for attaching of a putter shaft, the hozel may be connected to the head in the region of the middle of the head or, more preferably, the hozel may be disposed at one side of the head.

The invention may be applied to putter heads of various general forms but preferably the head is a blade putter head.

In the invention as defined above, it is an essential feature of the invention that at least the part of the front face that is intended for striking the ball is of spherical shape (or at least of approximately spherical shape); thus the radius of curvature of the face about a vertical axis and about a horizontal axis are the same (or at least approximately the same). In another aspect of the invention, however, it is not essential for the front face to have substantially the same curvature vertically as it has horizontally. Thus, according to another aspect of the invention there is provided a golf putter head including a front face for striking a golf ball, wherein at least the part of the front face that is intended for striking the ball has, when viewed from above, an arcuate shape of circular form with the centre of the circle being to the rear of the putter head. In the case of a putter head according to this aspect of the invention, at least the part of the front face that is intended for striking the ball may have a different curvature in the vertical direction, or even have no curvature at all in the vertical direction. In the latter case, the face is preferably inclined upwardly and outwardly in order that it makes contact with the ball above the level of the centre of the ball. It will be understood that features of the invention described above in connection with the golf putter head having an at least partly spherical front face are also applicable to the putter head of this aspect of the invention. For example, the ranges of radius of curvature given above may apply to either or both of the curvature vertically and horizontally. The radius of curvature of the face about a horizontal axis may be greater than the radius of curvature about a vertical axis.

The present invention also provides a golf putter including a shaft and a golf putter head as defined above, the shaft being attached to the putter head.

By way of example certain embodiments of the invention will now be described with reference to the accompanying drawings, of which:

FIG. 1 is a plan view of a first form of putter head embodying the invention;

FIG. 2 is a side view of the putter head in the direction of the arrows A-A marked in FIG. 1;

FIG. 3 is a rear view of the putter head in the direction of the arrow B marked in FIG. 1;

FIG. 4 is a plan view, similar to FIG. 1, of a second form of putter head embodying the invention;

FIG. 5 is a rear view, similar to FIG. 3, of the second form of putter head embodying the invention; and

FIG. 6 is a diagram illustrating a benefit of the invention.

The putter head shown in FIGS. 1 to 3 is a blade putter head generally comprising a blade 1, a sole plate 2, a hozel 3, weighted end portions 4, and ribs 5. The hozel 3 defines a cylindrical elongate cavity 6 for receiving a shaft (not shown) in a manner known per se. In the embodiment of FIGS. 1 to 3, the bottom of the cavity 6 is in the middle of the putter head.

The blade 1 is of spherical shape, with the centre of the sphere to the rear of the head. In a particular example of the invention the sphere on which the front face of the blade 1 lies has a radius of 150 mm and, when the putter head is positioned on the ground in its intended position for striking a ball, with the longitudinal axis of the hozel disposed in a vertical plane, the centre of that sphere is 23 to 25 mm above the ground.

FIGS. 4 and 5 show a blade putter head of generally similar design to that of FIGS. 1 to 3 and corresponding parts are referenced by the same reference numerals. It should be noted that in FIG. 4 the hozel 3 is not shown, but as may be seen from FIG. 5, in this modified design the hozel 3 is provided at one side of the putter head.

FIGS. 4 and 5 also show various dimensions of one particular example of the invention. The dimensions marked are as follows:

R (radius of sphere): 150 mm t: 5 mm
W: 95 mm                     y: 25 mm
d: 30 mm                     x: 15 mm
h: 32 mm

The hozel 3 is inclined at an angle of 15 degrees to the vertical and the internal diameter of the hozel is ⅜ inch (9.5 mm).

In the example of FIGS. 4 and 5, the sole plate is formed with a slot 7 in the sole plate, immediately behind the blade, and the top of the sole plate 2 is chamfered along its rear edge.

Use of a putter incorporating the putter blade of either of the two versions of putter head described above will now be described with reference to the diagram of FIG. 6 in which a ball 8 is shown, a spherical putter blade 1 is diagrammatically illustrated and the sphere on which the front face of the putter blade 1 lies is indicated by a dotted line.

The target line T along which a player wishes to strike the ball is shown in FIG. 6 and the putter blade 1 is shown with the part of the putter blade that is about to make contact with the ball perpendicular to the target line, as is desired. As can be seen from FIG. 6, if, for example, the putter blade is twisted from the orientation shown in an anti-clockwise direction that will tend to close the face of the putter and send the ball to the left of the target line; if, however, at the same time as the face of the putter is closed, the putter is moved anti-clockwise or downwardly as seen in FIG. 6 then that will compensate for the turning of the face of the putter and result in the part of the putter blade in contact with the ball remaining substantially perpendicular to the ball.

The putter head of the invention may be made of any suitable material. Commonly putter heads are made of metal and metal alloys and the putter head of the invention may for example be made of an aluminium bronze alloy.

Whilst in the particular example described above the radius R of the sphere is 150 mm, it may be preferable for the radius to be substantially greater. For example, radiuses of 1000 to 1500 mm have been tested and found to be satisfactory.

Claims

1. A golf putter head including a front face for striking a golf ball, wherein at least the part of the front face that is intended for striking the ball is defined by a sphere the centre of which is to the rear of the putter head and wherein, when the putter head is orientated in an upright position appropriate for striking the ball, the centre of the sphere is more than 22 mm above the bottom of the putter head.

2. A golf putter head according to claim 1, in which the whole of the front face of the head is defined by the sphere.

3. A golf putter head according to claim 1, in which the radius of the sphere is in the range of 100 mm to 2000 mm.

4. A golf putter head according to claim 1, in which, when the putter head is orientated in an upright position appropriate for striking the ball, the centre of the sphere is from 23 to 25 mm above the bottom of the putter head.

5. A golf putter head according to claim 1, further including a hozel for attachment of a putter shaft.

6. A golf putter head according to claim 5, wherein the hozel is disposed at one side of the head.

7. A golf putter head according to claim 1, in which the head is a blade putter head.

8. A golf putter head including a front face for striking a golf ball, wherein at least the part of the front face that is intended for striking the ball has, when viewed from above, an arcuate shape of circular form with the centre of the circle being to the rear of the putter head.

9. A golf putter including a shaft and a golf putter head according to claim 8, the shaft being attached to the putter head.