Clubhead having alignment means and high moment of inertia spaced from center of gravity thereof

Abstract

Presented is a golf club in the nature of a putter designed especially to distribute the mass of the clubhead and therefore the moment of inertia of the clubhead on opposite sides of the center of gravity. In another aspect, this quality in the golf club is provided by the configuration of the clubhead which simultaneously provides means pointing to the "sweet spot" on the clubface so as to facilitate alignment of the sweet spot with the intended direction of travel of the ball.

Description

BACKGROUND OF THE INVENTION

A myriad of books and monograms have been written about the game of golf, running the gamut from club design, proper stance, proper wrist motion, to publications such as advertisements for the sale of golf clubs which represent that the weight of the clubhead is scientifically placed behind the ball to achieve greater distance on every shot. Experience and research has taught that there are at least five basic causes of a golf ball not moving in the direction intended by the golfer. These five causes are:

1. Off-center impact, which may be defined as hitting the ball other than at a point in the center of the club face;

2. Off-line swing, which is defined as swinging the clubhead through the ball in a direction other than along the chosen line of aim;

3. Face of club off-line to swing, which constitutes hitting the ball with the clubface aiming along a different line from that through which the clubhead is being swung;

4. In the case of putting, taking the club back improperly, resulting in the face of the club being off-line to the swing at the moment of impact; and

5. Failure to hit the sweet spot of the ball, which may be defined as that specific point on the ball which is oriented on the end of a diameter which extends in the direction in which the ball is intended to move. So far as is known, there are no other ways of hitting a crooked shot. Aside from errors in judgement relating to how hard to hit the ball, these five points encompass most mechanical reasons for missing shots. Accordingly, it is one of the objects of this invention to provide a golf club designed to minimize the tendency for hitting the ball at a point other than the center of the clubface by providing means associated with the clubhead for clearly pointing to the sweet spot of the clubface and the intended direction of movement of the ball.

It is, of course, well known that each golf club, according to its design, possesses a center of gravity which in general lies along a line extending between the front and rear faces of the club and which is generally perpendicular to the front face of the club and which also includes the sweet spot of the clubface. Thus, upon impact of a golf ball with a golf club swung along a line including the center of gravity, i.e., the sweet spot of the clubface, the impact will slow the whole clubhead considerably but, because impact has occurred at the center of gravity, there will be little or no tendency of the clubhead to twist in relation to the ball at the moment of impact. It is equally true, that to strike the golf ball at a point off-center from the center of gravity of the clubhead results in the considerable force applied to the clubhead and the golf ball at the moment of impact slowing the clubface down but also twisting it around at an angle so that the clubhead tends to rotate around a vertical axis extending through the center of gravity of the clubhead. Accordingly, it is another of the objects of this invention to provide a golf clubhead which minimizes this tendency of the clubhead to rotate about a vertical axis through the center of gravity of the head even if the ball is struck at a point on the clubhead off-center from the center of gravity.

When using clubs other than putters, the effect of striking the ball with the clubface at a point other than the sweet spot of the club generally results in the ball being spun. The "rule of a spin" in golfing ballistics, stated broadly, is that a golf ball flying through the air tends to curve in the direction in which the front of the ball is moving by virtue of its spin. Thus, a ball struck below the center of gravity of and by the clubface tends to rotate or twist the clubhead toward the ball, thus turning it downward during the course of impact, and resulting in reduced loft of the ball because of reduction of the angle above horizontal at which the ball is dispatched and reduction of the backspin ordinarily imparted to the ball. Reduction of the backspin causes the ball to fly lower than it would ordinarily fly. Accordingly, it is still another object of the present invention to provide a golf clubhead in which the mass of the golf club and its center of gravity in relation to the front and rear faces of the club is closer to the front face of the club so as to minimize the tendency of the clubhead to twist when striking a ball above or below the center of gravity of the clubhead.

In swinging a golf club, such as a wood, it is customary for the golfer to line up the golf ball with the target. The difficulty is that many golfers will then proceed to swing the clubhead through the ball in a direction other than along the chosen line of aim which extends through the sweet spot of the ball, the sweet spot of the club and the target. There are many reasons why a golfer will do this, some of them including a bad grip, or a "shut" or "open" face, or shifting his stance around in order to swing across himself to square the clubface with the golf ball substantially perpendicular to the line between the ball and the target. The solution to this problem is to stop swinging the club off-line to the target and start swinging it on-line to the target. In practice, however, in the course of a swing, there is little if anything in the design of conventional clubs to help the golfer line up the face of his club with the imaginary line extending between the ball and the target. The same may be said with respect to putters and "irons." Accordingly, it is another object of this invention to provide a golf clubhead providing a visual reference enabling the golfer to more easily place the face of his golf club exactly perpendicular to the target line, and to swing the clubhead so that it swings through the ball in line with the intended direction of movement of the ball.

One of the factors that contributes to uniformity in a golfer's play is the "swingweight" of a golf club, particularly with respect to "irons" and "woods." Preferably, golf clubs are "matched" for the player, meaning that the "feel" of each of the clubs when swung has been adjusted by adjusting the "swingweight" of the club so that all of the clubs in the set have the same "swingweight" and therefore the same "feel." Adjusting the "swingweight" of a club involves the moment of the club's weight, which is defined as the "pull" of the club's weight about a point 12 inches from the grip-end of the shaft when the club is held horizontal. With respect to putters, adjustment of the weight of the clubhead is important in relation to the effect of the clubhead on the ball vis-a-vis slow and fast greens, wet and dry greens, and the different textures of grass. Accordingly, another object of this invention is to provide a golf club incorporating means for adjusting the weight of the golf clubhead so as to adjust the "swingweight" of the club, and for adjusting distribution of the weight of the clubhead to vary the moment of inertia.

Most golf clubs are fabricated from either metal or wood, metal being used for putters and "irons," while wood is generally used for drivers. Where wood is used, it is common to provide a face-plate of a suitable synthetic resinous material secured to the face of the club. The strike surface of the face-plate may be either flat or slightly bulged so as to affect the flight of the ball in relation to the longitudinal axis of the fairway, or the face-plate may be vertical or it may be slightly inclined, the angularity of the face having a significant affect on the spin of the ball and the loft of the ball as a result of such spin. By way of contrast, spin is of negligible importance in a putt shot because the ball is in either skidding or rolling contact with the grass. Accordingly, it is still another object of the invention to provide a golf clubhead in which these factors may be readily changed in connection with a given golf club by providing a golf club in which the face-plate may be quickly removed and another having different characteristics substituted therefor.

Another object of the invention is to provide a golf club fabricated from either wood or metal which possesses a face-plate fabricated from a non-breakable glass fabric and epoxy material.

Still another object of the invention is the provision of a golf club fabricated from non-breakable synthetic resinous material, and which may have imbedded therein means for distributing the mass of the golf club to points widely spaced on opposite sides of the center of gravity of the golf club.

The invention possesses other objects and features of advantage, some of which, with the foregoing will be apparent from the following description and the drawings. It is to be understood however that the invention is not limited to the embodiment illustrated and described, as it may be embodied in various forms within the scope of the appended claims.

SUMMARY OF THE INVENTION

In terms of broad inclusion, the golf club of the invention in one or another of its aspects relates to putters, irons, and woods, and comprises a clubhead having a front striking face and rear trailing face, end edges and in a putter a body defined between the front and rear faces which has its greatest dimension in terms of depth measured between the front and rear face at points spaced on opposite sides of the median line between the heel and toe of the club, considered herein to be coincident with the center of gravity of the clubhead. Means are also provided in connection with the configuration of the clubhead to distribute the mass of the clubhead on opposite sides of the center of gravity, and for indicating to the golfer the location of the center of gravity by providing a centrally disposed flange projecting upwardly from the upper surface of the clubhead and pointing to the sweet spot of the clubface, understood to be on an axis extending through the center of gravity of the clubhead, and if properly swung, also pointing to the sweet spot on the ball. Means are also provided in association with such raised flange or grooves providing a reference for use by the golfer in judging whether the face of the club is square with respect to the intended line of flight of the ball or with an imaginary line connecting ball and target. In one aspect of the invention, means are provided for selectively accommodating additional weights which may be added to the clubhead to modify its "swingweight". In still another aspect of the invention, means are provided for quickly and easily detaching the face-plate from the clubhead and substituting another face-plate fabricated from non-breakable glass fabric and epoxy material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a golfer in the act of swinging a golf club according to the invention.

FIG. 1A is a diagramatic view showing the alignment the club, ball and target.

FIG. 2 is a perspective view of the golf club of the invention, the shaft being broken away to reduce its length.

FIG. 3 is a top plan view of one embodiment of the golf club of the invention, the shaft being broken away.

FIG. 4 is a front elevational view of the golf club of the invention as illustrated in FIG. 3, the shaft being broken away, and the face-plate being partially retracted to show the underlying structure.

FIG. 5 is a bottom plan view of the clubhead of the invention illustrated in FIGS. 3 and 4.

FIG. 6 is a vertical cross-sectional view through the center of gravity of the golf club, the section taken in the plane indicated by line 6--6 in FIG. 3, with the central flange being shown in elevation for purposes of clarity.

FIG. 7 is a vertical sectional view similar to FIG. 6 and showing a second embodiment of the clubhead having the same configuration but omitting the detachable faceplate and weight control means therefrom.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In terms of greater detail, the golf club of the invention has been illustrated as a putter for purposes of convenience, and comprises a clubhead designated generally by the numeral 2 and mounted in any suitable manner on the lower end of shaft 3. Referring to FIG. 1, the putter embodiment there shown is similar to the embodiment illustrated in FIG. 7, the clubhead including a face 4, here shown slightly inclined to the vertical. It will of course be obvious that the face 4 may be exactly vertical with no inclination whatsoever if desired, especially since the affect of loft and backspin in connection with a putt shot is negligable. As previously discussed, the provision of an inclined face on a wood or iron club generally produces spin to the ball, thus increasing the loft of the ball as it flies from the club.

The body of the clubhead is also provided with a top surface divided into three distinct areas designated 6, 7 and 8, and a lower surface 9 seen in FIGS. 5 and 7. As illustrated in FIGS. 1 and 3, the surface areas 6 and 7 are generally triangular in configuration, the edge of each triangular area coincident with the front face 4 of the clubhead constituting the hypotenuse of the triangular area, while the edges of the triangular area, which converge to a point midway between end edges 12 and 13 of the clubhead constitute flanges 14 and 15, respectively, which diverge from the front face of the club and extend in flange portions 14' and 15' beyond the rear face 16 of the clubhead. The surface 8 of the clubhead is also generally triangular in configuration, being defined along two sides by the flanges 14 and 15 and on the third side by the rear face 16 of the clubhead. Projecting from the top surface of the club and specifically bisecting the area defined by the surface 8, is a vertically and rearwardly extending stabilizer flange 17, the root of which merges integrally as at 18 with the top surface 8 of the clubhead. It will thus be seen that between the flange 17 and flanges 14 and 15, the rear face 16 of the clubhead merges smoothly with the flanges and is integral therewith.

As indicated in FIG. 7, the lower surface 9 of the clubhead is smoothly curved so that as it merges with the rear face of the clubhead, the thickness of the clubhead adjacent its rear face is somewhat less than the thickness of the clubhead at its front face. Conversely, the flanges 14 and 15, at their point of connection to the rear face of the clubhead, are greater in dimension than the rear face of the clubhead, thus causing the flanges to project somewhat above the top surfaces 6, 7 and 8 of the clubhead. Because of the direction in which these flanges 14 and 15 are directed, they converge arrow-like toward a point at the front face of the clubhead which is aligned with the center of gravity of the clubhead, thus making it possible for the player to adjust his grip so that the point of convergence of these flanges strikes the ball dead center, thus insuring that the center of gravity of the clubhead will be lined up with the sweet spot of the ball.

In like manner, the flange 17, pointing as it does to the point of convergence of the flanges 14 and 15, may be used as a reference line, permitting alignment of this flange with the proposed line of flight of the ball from the point of impact to the target. It will of course be understood that variations in the line of flight deviating from a straight line between the point of impact and the target may be affected in various ways by controlling the position of the clubface. In general, however, for a perfect straight shot, it is desirable that the clubhead meet the sweet spot of the ball at the sweet spot of the clubhead, which lies midway between the top and bottom surfaces of the clubhead and in line with the center of gravity of the clubhead.

Referring to FIGS. 3-6, the embodiment there shown is generally similar in its configuration to the clubhead illustrated in FIGS. 1, 2 and 7, with the exception that in this embodiment the body of the clubhead has been bored out to provide bores 21, 22, and 23, positioned in the body of the clubhead so that one of the bores 22 aligns with the center of gravity of the clubhead while the two remaining bores are formed about axes equally spaced on opposite sides of central bore 22. The bores are proportioned and interiorly threaded to snugly receive pellets 24, 26 and 27, preferably metal, the pellets being retained within their respective bores by complementary threads and covered by a detachable face-plate 28, preferably fabricated from a non-breakable laminated glass fabric and epoxy material such as that manufactured and sold by Synthane-Taylor Division of Alco Standard Co., Valley Forge, Pennsylvania and sold under the tradename G-10 and G-11. The face-plate 28 is preferably provided with an aperture 29 and beveled top and bottom edges 31 and 32 adapted to be snugly received in a slot or groove 33 formed in the face of the club and having complementarily beveled edges 34. A suitable flat head screw 35 may be utilized to retain the non-breakable epoxy (G-10 or G-11) face-plate on the face of the club and thus retain the weights 24-27 snugly within their respective bores. It will of course be apparent that the non-breakable face-plate may be permanently attached to the clubhead in any suitable manner.

It will thus be seen that pellets of different materials may be deposited in the bores, to vary the weight of the clubhead for various reasons and over a useful range. For instance, a player that desires a matched set of woods and irons may choose weights which will produce this effect. On the other hand, if it is clearly the desire of the player to increase the weight of the clubhead without regard to its swingweight characteristics, the heaviest type pellets may be deposited in the bores, or the center pellet may be omitted to increase the moment of inertia. In other respects, the clubhead illustrated in FIGS. 3-6 is identical to the clubhead illustrated in FIGS. 1, 2 and 7 and corresponding parts having been designated by the same reference numbers. In regard to weight of the clubhead, it should be understood that the entire clubhead may be fabricated from a synthetic material as distinguished from metal or wood, and the weight distribution controlled by embedding a metal insert of appropriate configuration within the body of synthetic material so as to secure the desired distribution of weight to increase the moment of inertia of the clubhead.

With respect to use of the flanges 14, 15 and 16 as a guide for controlling the direction of swing of the golf club, perhaps the best illustration of the effectiveness of this means is contained in FIGS. 1, 1A and 3. Thus, the golfer may utilize the central flange 17 to guide his swing so that the clubhead follows a direction in alignment with the line between the ball and target. Misalignment by striking the ball to one side or the other of the central flange 17, and thus modifying the inertial response of the clubhead, is instantly obvious when it occurs because the flange 17 provides the kind of reference line easily observed by the eye in the split second of impact. It should of course be understood that the flange 17 functions as a reference line. Therefore, a groove formed in the clubhead in place of flange will function in the same way.

On the other hand, it is also advantageous that the clubface be oriented perpendicular to the intended line of flight of the ball and for this purpose, the face of the club taken in cooperation with the ends of the flanges 14, 15 and 17 define a rectangle which forms a plane of reference which the golfer may use to insure that the long dimension of his clubface is perpendicular to the intended line of flight of the ball. Any deviation from such a relationship is quickly evident because the diverging flanges 14 and 15, provide a reference in relation to the ball which enables the golfer to keep the angles between the flanges 14-15 and the ball of equal value, thus insuring that the clubface is perpendicular to the direction of movement of the clubhead and the intended direction of movement of the ball.

With respect to distribution of the mass of the clubhead so that the center of gravity lies centrally located with respect to the end edges 12 and 13, (toe and heel) and closer to the front face 4 of the club than to the rear trailing face 16 thereof, the thickness of the clubhead between the lower surface 9 thereof and the top surface defined by the pair of triangular areas 6 and 7 is relatively constant and relatively thick in relation to the thickness of the triangular portion 8 defined between the flanges 14-15 and the rear face 16. This has the effect of distributing a major portion of the mass of the club on opposite sides of a median line extending through the center of gravity of the club. In this way, the moment of inertia of the clubhead is increased substantially so that if the clubhead strikes the golf ball at a point to one side or the other of the center of gravity, i.e., at a point other than midway between the heel and the toe of the club, the added mass (greater moment of inertia) of the clubhead spaced from the center of gravity will reduce the tendency of the club to twist about a vertical axis extending through the center of gravity of the clubhead. It has been found advantageous to form the body of the clubhead so that the greatest dimension in depth of the clubhead measured between the front face and the rear face thereof occurs approximately two-thirds of the distance from the center of gravity to the heel and toe of the clubhead. Thus, if the overall length of the clubhead is taken to be L, then the distance from the center of gravity to the point of greatest dimension in depth of the body will be L/3. These proportions are clearly illustrated in the drawings and indicated by notation in FIGS. 3 and 5.

Claims

Having thus described the invention what is claimed to be new and novel and desired to be protected by United States letters patent is as follows:

1. A golf club comprising:

a. a clubhead having a body including top and bottom surfaces, a front face, a rear face spaced from said front face, and end edges connecting said front face to said rear face, the spacing between the front and rear faces of the body adjacent said end edges being substantially greater than the front to rear face spacing at a point approximately midway between said end edges, the length of said front face being substantially larger than the depth of said clubhead measured between the front face and the rearmost portion of the clubhead;

b. shank means anchored in said clubhead adjacent one of said end edges and constituting a handle for said golf club; and

c. a pointer on said clubhead converging from said rear face of the body toward said front face, the apex of said pointer being coincident with said front face and said top surface and designating the midpoint of said front face measured between said end edges;

d. said pointer extending from said front face rearwardly to at least said rear face to designate the midpoint of said front face between said end edges and flange means on the clubhead adjacent said pointer and equally divergent on opposite sides thereof from said midpoint of the front face and defining an apex thereat and extending rearwardly to at least said rear face adjacent said end edges whereby a golfer may utilize said flange means to determine if the clubhead is square with the intended line of flight of the ball.

2. A golf club comprising:

a. a clubhead having a body including top and bottom surfaces, a front face, a rear face spaced from said front face, and end edges connecting said front face to said rear face, the spacing between the front and rear faces of the body adjacent said end edges being substantially greater than the front to rear face spacing at a point approximately midway between said end edges, the length of said front face being substantially larger than the depth of said clubhead measured between the front face and the rearmost portion of the clubhead;

b. shank means anchored in said clubhead adjacent one of said end edges and constituting a handle for said golf club; and

c. a pointer on said clubhead converging from said rear face of the body toward said front face, the apex of said pointer being coincident with said front face and said top surface and designating the midpoint of said front face measured between said end edges;

d. said top surface being disposed between said front and rear faces and said end edges and defined by three triangular areas, two of said triangular areas being mirror images of each other and encompassing the end edges and front face of said clubhead while said third triangular area defines the remaining surface of said clubhead between said mirror image triangular areas and said rear face, the thickness of said clubhead adjacent the rear face measured between the top and bottom surfaces of said third triangular area being less than the thickness of the front face measured between top and bottom surfaces.

3. The combination according to claim 2, in which the depth of said club measured from the front face to the rear face thereof is greatest at points approximately two-thirds of the distance from the center of gravity of the club to each end edge thereof, the thickness of said clubhead between the bottom surface and the top surface defined by said pair of mirror image triangular areas being relatively constant and thicker than said third triangular area, whereby a major portion of the mass of said clubhead lies on opposite sides of the center of gravity of the clubhead.

4. The combination according to claim 2, in which corresponding sides of said mirror image triangular areas diverge from the midpoint of said front face and constitute flanges extending rearwardly to at least the rear face adjacent said end edges of said clubhead.

5. The combination according to claim 4, in which said pointer includes a centrally disposed rib extending rearwardly from said front face to at least said rear face, the end of said centrally disposed rib adjacent said rear face being generally in line with the ends of said divergent flanges adjacent said rear face, whereby a plane including the rear edges of said flanges and said rib will lie substantially parallel to the front face of the clubhead.

6. The combination according to claim 2, in which said third area disposed between the mirror image triangular areas of said top surface is bisected by said pointer, said pointer including a centrally disposed rib extending perpendicularly from the front face of said clubhead rearwardly to at least the rear face thereof, said rib having a wider dimension at its end adjacent said rear face than at its end adjacent the front face whereby said rib points to the midpoint of said front face.