GOLF CLUB HEAD WITH ADJUSTABLE WEIGHTS

Abstract: It is described a golf club head comprising a front face (3) or striking face, a bottom face (2) and a top face, said golf club head is provided with one or more movable screws or weights (7) for adjustment of the club heads balance. The weights or screws (7) are made of a material with a relatively high specific gravity, and are provided in tube sleeves (1) inside the club head. The screw (7) can be adjusted to any desired position between the ends of the tube sleeves (1) and thereby adjust the balance point of the club head. The tube sleeves (1) are provided slanting from the front face (3) of the club head down towards the rear part of the bottom face (2) of the club head.

Description: Golf club head with adjustable weights The present invention regards a golf club head with adjustable weights in accordance with the preamble of Claim 1, preferably a golf club head made of metal, such as a driver or a wood. Dimensions, appearance and choice of materials for golf clubs are to a large extent determined by the rules of The Royal and Ancient Golf Club of St. Andrews and The United States Golf Association. The rules of these organisations have been adopted by most countries, and making changes to the golf clubs within the framework drawn up by these rules can be somewhat difficult. The above organisations have identical rules. An object of the present invention is to be able to adjust the weight distribution and thereby the balance of golf club head in such a manner that the changes lie that which is allowed according to Rule 4 and Appendix II. All golf clubs have a common feature; that of having a low centre of gravity in order to give the ball an underscrew and thereby a high trajectory. At the same time, the actual striking surface must be rigid in order for the ball to go far. In order for the golf club head to be stable, it is also important that the masses on either side of the centre of the striking surface (the sweet-spot) is approximately equal. To achieve the largest possible sweet-spot, it is important to position most of the mass as far away from the centre of the striking surface as possible. The reason for this is that the golf club head becomes more stable or forgiving, because the inertia of the club about the centre of the striking surface becomes greater. Positioning the mass far down and forward, i.e. near the striking surface, would result in the club head not having sufficient stability From US patent 1 133 129 there is known a golf club head made of wood or solid iron, which head has one or more threaded sleeves in which can be provided weights or leads in order to adjust the centre of gravity of the club head in a direction across the axis of the club handle. The weights or the leads can only be moved in the horizontal direction, which means that the possibilities of varying the centre of gravity of the club head are limited. From US patent no. 3 652 094 there is known a wooden golf club head into which has been screwed threaded sleeves. Plugs may be screwed into these sleeves in order to alter the balance and/or the swing weight of the club head. From US patent no. 5 464211 there is known a metal golf club head having a threaded sleeve in which can be placed a body for compression of the striking surface of the club head. Further, a putter head incorporating adjustable weights is known from UK patent application no. GB 2 334454 A, and a similar putter head with an adjustable weight is known from international patent publication WO 96/32165. An object of the present invention is to be able to adjust the centre of gravity of the club head, and thereby the trajectory of the ball. Another object is to be able to adjust the centre of gravity of the club head according to the skill and playing style of the individual. These objects and advantages are achieved by means of a metal golf club head with adjustable weights, which club head includes at least a bottom face, a front face and a top face, in which club head is provided one ore more tubular sleeves extending from the rear part of the club forward to the front face, in which tubular sleeves may be provided screws or weights, characterised in that the tubular sleeve or sleeves are provided at an angle from the centre line of the front face down towards the rear part of the bottom face, and that one end of the tubular sleeve is open to the bottom face The tubular sleeve or sleeves are preferably equipped with an internal thread or grooves, a complementary shaped screw or weight arranged in each tubular sleeve, which screw is selectively adjustable to any position between the ends of the tubular sleeve. Preferably, the screws are manufactured from a material or a mixture of materials with a high density of mass, e.g. a metal or metal alloy, preferably tungsten. The opening of the tubular sleeve may in accordance with one embodiment be provided with a lid. In accordance with a preferred embodiment, the screw has a length that essentially corresponds to the length of the tubular sleeve, and the screw is preferably in the form of a cylindrically shaped, externally threaded body. Preferably, one or more parts of the screw consist of a metal or a metal alloy, with the remaining part consisting of plastic, which parts are preferably joined by gluing. The golf club head may include two tubular sleeves positioned approximately symmetrically about the centre line of the striking surface, with associated moveable screws. Preferably, the tubular sleeve or sleeves are cast integrally with the rest of the club head. In the following, the invention will be explained in greater detail by means of non- limiting examples of embodiments, with reference to the accompanying drawings, in which: Figure 1 shows a sectional side view of a golf club head in accordance with the present invention; Figure 2 shows a top section of a golf club head in accordance with figure 1, showing the positioning of two tubular sleeves with screws provided at the bottom of the tubular sleeves; Figure 3 is a sectional view of a golf club head according to Figure 2, in which the screws are arranged at the opening of the tubular sleeves; Figure 4 is a sectional view of a golf club head according to Figures 2 and 3, in which the screws are arranged diagonally in relation to each other; Figure 5 is a sectional top view of a golf club head showing the club head with a tubular sleeve positioned at the centre of the club head and an associated screw; Figure 6 is a perspective drawing showing the club head from the rear, with a tubular sleeve and associated screw; and Figure 7 is a perspective drawing showing the club head from the rear, with two tubular sleeves and associated screws. Figure 1 shows a sectional view of a club head termed a driver or a wood. The club head shown includes a front face 3 and a bottom face 2. In the embodiment shown, the bottom face 2 includes one or more tubular sleeves 1 attached to the bottom face 2 by means of appropriate fixing means, such as welding, gluing or integrally cast with the club head. The tubular sleeve or sleeves are positioned in a manner such that the opening of the tubular sleeve is located at the rear part of the bottom face of the club head and are positioned at an angle up towards the centre 4 of the striking surface (front face). As shown in Figure 1, which shows a vertical cross section of the club head, the tubular sleeves will be approximately diagonal. The tubular sleeve is provided with an internal thread or grooves 6. A complementary shape screw or weight 7 made from a material, preferably metal, with a relatively high density or mixture of several materials, such as tungsten, may be screwed into the tubular sleeve 1. The length of the screw 7 is shorter than the length of the tubular sleeve, so as to allow it to be screwed back and forth in the tubular sleeve as desired. In the state shown in Figure 1, the screw 7 is screwed in almost to the bottom of the tubular sleeve 1, however it is obvious that the screw may be placed at any position between the ends of the tubular sleeve 1. A lid 8 may be fastened to the opening of the tubular sleeve 1, which prevents grass and earth from penetrating into the tubular sleeve 1. Preferably, this lid is screwed to the opening of the tubular sleeve 1. In the embodiment shown in Figure 1, the tubular sleeve is arranged at an incline from the bottom face 2 and up towards the centre line 4 of the front face (striking surface) 3. Figures 2 - 4 all show sectional views of the club head seen from above, with two tubular sleeves 1 and two associated screws or weights 7. The difference between these three figures is the mutual positioning of the screws 7. The purpose of being able to move the screws 7 in the tubular sleeves is to be able to achieve the desired balance of the club head. In the state shown in Figure 2, both screws 7 are positioned approximately at the bottom of the tubular sleeves 1, i.e. as close as possible to the centre line of the striking surface 3. This positioning of the screws 7 will result in the underscrew-effect being reduced or neutralised, which will give the maximum distance for the ball. At the same time, the club head will be stable, because the weights, i.e. the screws 7, are located as far to the side of the centre of the striking surface as possible. Practical experiments have shown that it is possible to alter the striking angle or lift by ± 1° by adjusting the position of the screw or screws 7 in the tubular sleeves 1. If the screws are positioned at the middle of the tubes and give a striking angle of e.g. 9°, it will be possible to change the striking angle to 8° by positioning the screw or screws at the position furthest away from the front face 3 (Fig. 3); correspondingly it will be possible to change it to 10° if the screws 7 are positioned as close to the front face 3 as possible (Fig. 2). In the position shown in Figure 3, both screws 7 are positioned at the furthest possible distance from and below the striking surface 3. This would give the ball an underscrew and thereby a high traj ectory . In Figure 4, the screws 7 are positioned opposite each other, i.e. one screw 7 near the striking surface 3 and the other screw 7 furthest away from the striking surface 3. In this situation, the balancing point of the club head is displaced, thus making it possible to prevent the occurrence of "slicing", i.e. when the ball gains a screw and goes of the course. Figure 5 shows a variation of the club head of Figures 2-4, incorporating only one tubular sleeve and associated screw 7. The longitudinal direction of the tubular sleeve 1 lies in the centre 4 of the striking surface 3. In Figures 6 and 7, the club head with one and two tubular sleeves respectively is shown in perspective from the rear. In order to prevent earth and grass from penetrating into the tubular sleeves, as well as to fulfil the previously mentioned requirements regarding no open holes in the club head, the opening of each tubular sleeve is covered by a lid 8. This lid may for instance be screwed to the end of the tubular sleeves 1 and be provided with a suitable groove or similar, so as to allow the lid to be removed by use of an appropriate tool. In accordance with a particularly preferred embodiment of the present invention, the tubular sleeve or sleeves are integrally cast with the rest of the club head. If the tubular sleeves are cast simultaneously with the club head, the tubular sleeves will form an integrated part of the club head, thus avoiding tension in the material. This will in turn result in a more stable club, without any loose, screwed or welded sleeves. In accordance with a further preferred embodiment, the screws or weights 7 have a length that essentially corresponds to the length of the tubular sleeve 1. The screws or weights 7 then consist of an externally threaded, cylmdrically shaped body of which part is a metal or metal alloy and the remaining part is made from a lighter material, for instance plastic. These two parts of the body are joined e.g. by gluing, so as to achieve a continuous body. An advantage of this embodiment over the embodiment shown in Figure 1 is that the open end of the tubular sleeve will not have to be shut by use of a lid. One end of the cylindrical body may be made from e.g. tungsten, while the other part of the body is made from plastic. The body may then either be inserted into the tubular sleeve 1 with the metal part forward, i.e. closest to the striking surface of the club head, or with the metal part to the rear. This solution makes it possible to use one and the same cylindrical body in order to move the centre of gravity of the club head both forwards and backwards. Another possibility is for the middle section to be made of metal and the two end parts of plastic.

Claims: C l a i m s 1. A metal golf club head with movable weights, which club head comprises at least a bottom face (2), a front face (3) and a top face, in which club head is provided one or more tubular sleeves (1) extending from the rear part of the club and forward towards the front face, in which tubular sleeves (1) may be provided screws or weights (7), characterised in that the tubular sleeve or sleeves (1) are provided at an angle from the centre line of the front face (3) down towards the rear part of the bottom face (2), and that one end of the tubular sleeve (1) opens onto the bottom face (2). 2. A golf club head in accordance with Claim 1, characterised in that the tubular sleeve or sleeves (1) are provided with internal threads or grooves (6), a complementary shaped screw or weight (7) is placed in each tubular sleeve (1), which screw (7) is selectively adjustable to any position between the ends of the tubular sleeve (1). 3. A golf club head in accordance with Claims 1-2, characterised in that the screws (7) are made from a material or a mixture of materials with a high density, e.g. a metal or a metal alloy, preferably tungsten. 4. A golf club head in accordance with one or more of the preceding claims, characterised in that the opening of the tubular sleeve (1) is provided with a lid (8). 5. A golf club head in accordance with one or more of the claims 1-3, characterised in that the screws (7) have a length that essentially corresponds to the length of the tubular sleeve (1), and that the screws (7) are in the form of externally threaded, cylindrical bodies. 6. A golf club head in accordance with Claim 5, characterised in that one or more parts of the screw (7) consists of a metal or a metal alloy and the remaining part of the screw (7) consists of plastic, which parts are j oined, preferably by gluing. 7. A golf club head in accordance with one or more of the preceding claims, characterised in that the golf club head comprises two tubular sleeves (1) placed approximately symmetrically about the centre line of the striking surface (3), with associated movable screws (7). 8. A golf club head in accordance with one or more of the preceding claims, characterised in that the tubular sleeve or sleeves (1) are integrally cast with the rest of the club head.

Inventors: DAMMEN PER, DAMMEN, PER
Applicants: DAMMEN PER, PROGOLF DEV AS, DAMMEN, PER, PROGOLF DEVELOPMENT AS
Application year: 2001
Main classification: A63B53
IPC codes: A63B53