Golf Club With Adjustable Weighting Plugs

Abstract

A golf club having provision for adjusting the swing weight and balance of the club. The club head includes a plurality of elongated cavities, each of which mounts an internally threaded sleeve. One or more externally threaded plugs are threadedly retained in each sleeve, the plugs being adapted to be rotatably translated along the length of the sleeve, or entirely removed therefrom, to change the balance and/or swing weight of the club.

Description

The present invention relates to a golf club, and more particularly, to a golf club head having provision for easily changing the swing weight and/or balance of the head.

It is well known that golfers are highly individualistic in the selection of their clubs and that it is conventional for a golfer to select a set of clubs on the basis of a particular length, a particular swing weight, and a balance which suits his individual preference. While the club length for a particular golfer will not normally change, it often happens that after the purchase of a set of clubs, the golfer will find that either the swing weight or balance, or both, is not to his liking, and he will want to have them changed.

In determining the swing weight of a golf club, it is conventional practice to horizontally position the club on a "swingweight" scale having a fulcrum positioned intermediate the ends of the club such that the head end is left unsupported. The swing weight is then determined from the upwardly directed force at the grip end of the club resulting from the moment of the club head portion of the club about the fulcrum. It will therefore be seen that the swing weight is a function of both the total weight of the head, as well as the length of the moment arm from the club head portion's center of gravity to the fulcrum. Thus any change in the weight of the club head or a change in the length of the moment arm will change the swing weight of the club.

In the past, a change in weight of the club head has been usually accomplished by drilling a hole in the club head, and either leaving it void if the weight is to be reduced, or filling it with heavy material, such as lead, if the weight is to be increased. It will be appreciated that this manner of adjusting the swing weight is not very satisfactory in that it does not provide a very finite or sensitive adjustment. In addition, the adjustment is irreversible in that once the hole is drilled, the club may never be returned to its original characteristics.

Heretofore, a change in the length of the moment arm to vary the swing weight of a club has not been possible except in connection with clubs having specially constructed club heads thereon. Such specially constructed club heads must be custom made and are either entirely hollow or have intricately formed cut-outs therein.

Another area of individual golfer preference is the "balance" of the club head, which as used herein refers to the distribution of weight within or the position of the center of gravity of the club head parallel to the base plate and perpendicular to the face of the club head. The balance of a club head may be changed by shifting the center of gravity thereof toward or away from the face of the club head without appreciably changing the swing weight thereof.

While it has been previously proposed to position an adjustable weight within the head of a golf club to vary its balance, all known designs also require a specially constructed club head to accommodate the weight as discussed above. None of these known designs are adapted for incorporation in a conventional club head.

Accordingly, it is an object of the present invention to provide a device for changing the weight and/or balance of a golf club and which is adapted for use with a club of conventional design after only a slight modification to the club head. In this regard, the device of the present invention comprises a sleeve having translatable weights therein which is adapted to be mounted in a conventional golf club by merely forming a cavity in the head.

It is a further object of the present invention to provide a sleeve which may be securely mounted in the head of a conventional golf club, the sleeve including weights therein which may be either entirely removed or selectively shifted to different positions within the club head.

It is a further object to provide a means for adjusting the weight and/or balance of a golf club in a manner which does not change the outer appearance of the club and which will not be apparent from a visual examination.

These and other objects and advantages of the present invention are achieved in the embodiment of the invention described herein through the provision of a golf club comprising an elongated shaft with an enlarged substantially solid head carried at one end. The head includes a relatively flat base surface, a generally vertically extending striking face, and at least one elongated cavity communicating with one surface of the head. An internally threaded sleeve is mounted within the cavity, and one or more externally threaded plugs are threadedly positioned in the sleeve. The plugs are adapted to be rotatably translated along the length of the sleeve to adjust the distribution of weight in the head. Alternatively, the plugs may be entirely removed from the sleeve to change both the balance and swing weight of the club.

Some of the objects and advantages of the invention having been stated, others will appear as the description proceeds, when taken in connection with the accompanying drawings, in which

FIG. 1 is a perspective view illustrating one embodiment of the present invention wherein the weight adjusting means is positioned in the bottom surface of a golf club head;

FIG. 2 is a sectional view of the golf club head taken substantially along the line 2--2 of FIG. 1;

FIG. 3 is an exploded perspective view of the weight adjusting means of the present embodiment;

FIG. 4 is a perspective view, partially sectioned, showing one embodiment of the plug of the present invention;

FIG. 5 is a side elevational view, partially sectioned, showing an alternate embodiment of the plug of the present invention;

FIG. 6 is a perspective view of the plug illustrated in FIG. 5;

FIG. 7 is a perspective view illustrating a second embodiment of the present invention wherein the weight adjusting means is positioned in the striking face of the head;

FIG. 8 is a sectional view of the golf club head taken substantially along the line 8--8 of FIG. 7;

FIG. 9 is a perspective view of the internally threaded sleeve of the embodiment of the invention illustrated in FIGS. 7 and 8.

A golf club 10 including a club head 12 embodying the teachings of the present invention is illustrated in FIGS. 1 and 2 of the drawings. It will be appreciated that the club head 12 is attached to an elongated shaft (not shown) in a conventional manner.

The outer configuration of the head is conventional in that it includes a relatively flat bottom or base surface 14, a transversely extending and somewhat upwardly inclined forward striking face 16, a top surface 18 and a rear surface 20. A metallic sole or base plate 22 is attached to the base surface by a number of screws 24. A reinforcing member 26 of plastic or similar material is attached to form an integral portion of the striking face 16 by a number of screws 28.

A number of elongated cavities 30 (four in the illustrated embodiment) are centrally positioned in the head 12 above the sole plate 22 and in communication with the base surface 14. The cavities may be formed in the club during its manufacture or at any time subsequent thereto, and will be seen to extend lengthwise in a direction substantially perpendicular to the base surface 14. The sole plate 22 includes a corresponding number of apertures 31 which are axially aligned with the cavities 30, and which are designed to freely receive the threaded portion of the screws 24. As seen in FIG. 2, the cavities adjacent the rear surface 20 of the head will necessarily have a somewhat shorter depth than the cavities adjacent the striking face 16.

Each cavity 30 is adapted to receive and retain an internally threaded elongated tubular sleeve 32 which substantially conforms to the configuration and depth of the associated cavity. As best seen in FIG. 3, the sleeve 32 includes a highly pitched external thread 34 which is adapted to facilitate retention of the sleeve in the cavity 30. The threads 34 are also preferably sharply pointed such that the above sleeve will have a "self-tapping" effect upon entry into the associated cavity 30 of the head 12. To facilitate threaded advancement of the sleeve into the cavity, one end of the sleeve may be slotted as at 36 to receive a screwdriver.

The sleeve 32 further includes an internally threaded bore 38 which is adapted to receive one or more adjustable weights in the form of externally threaded members or plugs 40. Also, the threaded portion of each screw 24 is adapted to pass through the aperture 31 in the sole plate and engage the threads 38 of the sleeve 32 to thereby retain the sole plate 22 on the head. It will be noted that the diameter of each aperture 31 is slightly less than the external diameter of the sleeve to provide an abutting interengagement therebetween.

As best seen in FIG. 4, the forward end of plug 40 includes a coaxial protuberance 42 having a rounded forward end, as well as a coaxial opening 44 in the rear end. The axial extent of the opening 44 is less than the axial extent of the protuberance 42, and the diameter of the opening 44 is slightly greater than the diameter of the protuberance 42 whereby contact between two axially aligned plugs is limited to a single point at the forward end of the protuberance 42 and the base of the opening 44. Thus when two plugs are in contact with each other in the sleeve, a rotational torque transmitted to one plug will not be transmitted to the adjacent plug. Thus a rear plug may be positioned to tightly abut an inner plug without advancing the inner plug.

To facilitate rotational transmission, each plug 40 includes a slot at 46 adapted to be engaged by a screwdriver or similar tool. Also, a circumferential resilient insert 48 may be mounted in a circumferential channel on the external threaded surface of the plug 40 to frictionally engage the internal threads 38 of the sleeve and thereby serve as a thread locking means.

An alternate configuration of the plug of the present invention is illustrated at 50 in FIGS. 5 and 6. The plug 50 is functionally similar to the plug 40 but includes a rounded or spheroidal surface 51 at each end. The two spheroidal surfaces are designed to limit the area of contact between adjacent plugs to preclude the transmission of a driving torque therebetween for the purposes set forth above. As in the case of plug 40, one end of the plug 50 may include a screwdriver slot 52, and a resilient locking insert 54 may also be provided.

It will be appreciated from the above description that the swing weight and/or balance of the club illustrated in FIGS. 1-2 may be adjusted by removing the screws 24 of the sole plate 22 and increasing or decreasing the number of plugs in one of the sleeves, or by rearranging the plugs in the different sleeves. Since the axial extent of each sleeve 32 substantially exceeds the axial extent of the associated plugs, it will be appreciated that several plugs may be accommodated by each sleeve.

A second embodiment of the present invention is illustrated in FIGS. 7 and 8. In this instance, the golf club 60 includes a club head 62 having a base surface 64, a transversely extending striking face 66, a metallic sole or base plate 68 attached to the base surface by a number of screws 69, and a plastic reinforcing plate 70 forming an integral part of the striking face 66 and attached thereto by the screws 72. Centrally positioned in the head 62, beneath the plate 70 are three elongated circular cavities 74 which may be formed in the club during its manufacture or at any time subsequent thereto. Also, the plate 70 includes three apertures 71 which are aligned with the three cavities 74 to permit the screws 72 to pass through the plate 70 and enter the associated cavity.

The cavities 74 are adapted to receive and retain a tubular sleeve 76 which is best seen in FIG. 9. The sleeve 76 is generally similar to the previously described sleeve 32 and includes an internally threaded bore 78 as well as highly pitched and sharply pointed external thread 80. The outer end of the sleeve includes a transverse flange 82 having a pair of apertures 84 therein to facilitate threaded advancement of the sleeve 76 into the associated cavity 74. The cavities 74 may include a counterbore 86 at the exposed outer end to accommodate the flange 82.

In the embodiment shown in FIGS. 7 and 8, it will be seen that the plate 70 is retained on the striking face 66 of the club by the screws 72 which are designed to extend through the apertures 71 of the plate 70 and engage the threads 78 of the sleeves 76. Preferably, the sleeves 76 extend substantially perpendicular to the striking face 66 since the heads of the screws 72 should be flush with the striking face. As in the previous embodiment, the swing weight and/or balance of the club 62 may be adjusted by removing the screws 72 and either translating the weights 40 to a different position within the sleeve 76, or by changing the number of weights in each sleeve.

While preferred embodiments of the present invention have been described in considerable detail herein, it will be appreciated that various modifications could be made without departing from the spirit of the invention. For example, a greater or lesser number of sleeves could be utilized rather than the number illustrated. Also, the retaining screws 24 and 72 could be positioned to enter the body of the head rather than one of the sleeves.

In the drawings and specification, there have been set forth preferred embodiments of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

I claim:

1. A golf club comprising,

an enlarged substantially solid head including a plurality of cavities communicating with one surface of said head,

means for adjusting the distribution of weight in said head, said means including an internally threaded sleeve mounted within each cavity and a plurality of externally threaded plugs each having at least one rounded end adapted to be threadedly mounted in each sleeve and adapted to be selectively located in any portion thereof, the rounded end of the respective plugs serving to limit the area of contact with each other to preclude transmission of a driving torque therebetween whereby an inner plug will not be rotated in the event the second plug is advanced into engagement therewith, a resilient thread locking means mounted on each of the plugs and carried by a portion of the external surface of the plugs for frictionally engaging the internal threads of said sleeve for holding the plugs in the desired adjusted position, said resilient thread locking means and the threads of the plug collectively serving as the sole means for maintaining the plug in the desired adjusted position,

said one surface of the club head having plate means, and

headed screws penetrating said plate means and threadably received in each of said sleeves for securing said plate means to the club head.

2. The golf club as defined in claim 1 wherein said head includes a relatively flat base surface, and a generally vertically extending striking face, and said cavities communicate with said base surface and extend along axes substantially perpendicular to said base surface.

3. The golf club as defined in claim 1 wherein said head includes a relatively flat base surface, and a generally vertically extending striking face, and said cavities communicate with said striking face and extend along axes substantially perpendicular to said striking face.

4. The golf club as defined in claim 1 wherein the external surface of each sleeve is threaded to retain said sleeve in said cavity.

5. The golf club as defined in claim 1 wherein the external surface of said sleeve includes a highly pitched thread to retain the sleeve in said cavity, and the outer end of said sleeve includes engagement means for facilitating rotational advancement of the sleeve into the cavity.

6. The golf club as defined in claim 1 wherein said plate means is a sole plate.

7. The golf club as defined in claim 1 wherein said plate means is a face plate.

8. The golf club as defined in claim 1, wherein the external surface of each sleeve is threaded to retain the sleeve in said cavity, and the outer end of each sleeve includes engagement means for facilitating rotational advancement of the sleeve into the cavity.