Golf club head with center of gravity near its striking face

The golf club head has a metal face plate, vertically spaced horizontal fins extending rearwardly from the back side thereof, and a central vertical rib between each pair of fins. Weight-carrying inserts are threadedly mounted in the face plate and also extend rearwardly from the back side of the face plate. Molded about the fins, ribs and inserts is a plastic material in the form of rigid or structural foamed polyurethane.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates generally to golf clubs, and pertains more 
particularly to a golf club having a head with its center of gravity 
located just rearwardly of the face plate. 
2. Description of the Prior Art 
It has long been recognized that the weight distribution within a golf head 
can influence the competency of a golfer. Therefore, various efforts have 
been made throughout the years to permit a golfer to vary the amount of 
weight or mass contained in the golf head so as to best suit his 
particular game style. 
U.S. Pat. No. 3,652,094 granted to Cecil C. Glover on Mar. 28, 1972 titled 
"Golf Club with Adjustable Weighting Plugs" treats the problem in a highly 
sophisticated manner, recognizing that the swing weight is a function of 
both the total weight of the head and the length of the moment arm from 
the club head portion's center of gravity to the fulcrum. Thus, it is 
brought out that 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. 
However, the above-alluded to patent does not recognize that having the 
center of gravity quite close to the striking surface of the face plate 
will produce even a more superior performance. Also, the patent fails to 
take into account that the concentrated impact forces resulting from 
striking a golf ball should be distributed or dissipated throughout the 
material constituting the golf club head. 
SUMMARY OF THE INVENTION 
Therefore, an important object of the present invention is to shift the 
center of gravity as far forwardly or toward the striking surface of the 
head of the golf club as possible. More specifically, an aim of the 
invention is to locate the maximum mass behind the club face, actually 
concentrating almost all of the mass between the centerline of the shaft 
and the club face. Stated somewhat differently, it is within the purview 
of the invention to locate the center of gravity of the club head so that 
it will be for all intents and purposes on the same axis as the centerline 
of the club shaft. Since the shaft centerline is only slightly to the rear 
of the striking face, the force couple caused by the centrifugal force of 
the head with respect to the shaft is for all intents and purposes 
eliminated. This is in contradistinction to when the center of gravity is 
offset considerably or displaced appreciably from the shaft's centerline, 
for then the force couple, of course, becomes more pronounced, increasing 
with the amount of offset or displacement. 
Another object of the invention is to obviate the side spin effect on the 
ball caused by the head rotating about the center of gravity of the club 
head due to an off center hit. 
Another object of the invention is to enable the golfer to adjust the 
weight balance in a toe to heel direction for the best proper weight 
distribution for his particular style of swing. 
Still another object of the invention is to achieve a maximum moment of 
inertia by distributing the mass with respect to the toe and heel of the 
club face. 
Yet another object is to effect the maximum energy transfer from the club 
head to the ball by reason of a one-piece or unitary casting making up the 
club face. 
Still further, an object of the invention is to provide a foam plastic that 
eliminates the problem of change in club head weight due to any 
accumulation of moisture. 
A further object is to provide a foam that eliminates the shrink and loose 
head problem attributable to moisture loss. 
A further object is to avoid having any inserts within the club head that 
are apt to become loss with a concomitant deleterious effect on the 
golfer's score. 
Another object of the invention is to provide a golf head that will absorb 
vibrational forces within the head. Stated somewhat differently, an aim of 
the invention is to transmit rearwardly the forces resulting from the 
striking of a ball, doing so in such a manner that the vibrational forces 
are better distributed throughout the material that will absorb or dampen 
such forces very rapidly. 
Quite briefly, my invention envisages an aluminum or magnesium face plate 
having integral fins extending rearwardly therefrom. The fins are 
generally horizontal and are spaced vertically with respect to each other, 
varying in their rearward length or distance from the face plate. More 
specifically, the middle fin extends the greatest distance rearwardly and 
the uppermost and lowermost fins a lesser distance. Between each pair of 
ribs is a centrally located vertical rib, each rib extending rearwardly 
the same distance as the fins it is intended to reinforce. Also, the face 
plate itself is thickest at the center thereof where the so-called "sweet 
spot" normally exists. In order to enable the golfer to vary the weight 
balance in a toe-to-heel direction, a pair of inserts are threadedly 
carried by the face plate and extend rearwardly therefrom, each having 
therein a preferred amount of high density metal, such as lead or a heavy 
tungsten alloy, so that the golfer can vary the weight by changing the 
amount of heavy metal in each insert. 
Whereas the face plate and fins integral therewith are of aluminum or 
magnesium, the major portion of the head is of foamed polyurethane 
plastic. Such a plastic is of low density and coupled with the fact that 
the aluminum or magnesium face plate, fins and ribs are also of fairly low 
density, although not as low as foamed polyurethane, the lead or tungsten 
alloy contained in the two inserts constitutes the greatest amount of mass 
and is disposed forwardly so that the center of gravity is very near the 
striking face, actually for all intents and purposes along the centerline 
of the golf club's shaft. Also, the two inserts are spaced quite far from 
a vertical plane which is perpendicular to the striking surface of the 
face plate and which passes through the center of gravity, thereby 
providing a maximum moment of inertia. The ribs are located in this 
vertical plane.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The golf club illustrating my invention has been indicated in its entirety 
by the reference numeral 10, and includes a head 12, a hosel 14, a shaft 
16 and face plate 18 providing a striking surface 19. The face plate 18 is 
of aluminum or magnesium. As can best be understood from FIG. 2, the face 
plate 18 is thicker midway between its upper and lower edges. 
Extending rearwardly from the back side of the face plate 18 are integral 
aluminum or magnesium fins 20, 21, 22, 23, 24, 25 and 26. More 
specifically, the uppermost fin has been labeled 20 and the lowermost fin 
26. The rear edges of these fins 20-26 have been identified by means of 
the suffix "a." By designating the rear edges as 20a, 21a, 22a, 23a, 24a, 
25a and 26a, it will be seen from FIGS. 2, 5 and 6 that the central or 
middle fin 23 has the greatest rearward length of all of the fins and the 
uppermost fin 20 and the lowermost fin 26 the shortest length. From FIG. 
5, it will be discerned that these various fins curve horizontally so that 
they extend rearwardly an even lesser distance in the region of the club 
head's toe and heel. 
Between each pair of fins is a reinforcing vertical rib, the upper ribs 
being best seen in FIG. 5. All of the ribs, however, are visible in FIGS. 
4 and 6 (and in phantom outline in FIG. 1). Progressing downwardly from 
the top, it will be perceived that the ribs have been identified by the 
reference numerals 27, 28, 30, 31 and 32. Their rear edges have been given 
the numerals 27a, 28a, 29a, 30a, 31a and 32a, respectively. The rib 27, 
which is intermediate the fins 20 and 21, extends rearwardly from the back 
side of the face plate 18 the same distance as the fins 20 and 21. In 
other words, the upper portion of the edge 27a is even with the lower 
portion of the edge 20a, and the lower portion of the edge 27a is even 
with the upper portion of the edge 21a. In like manner the edge 28a is 
coterminous with the edges 21a and 22a. The same holds true for the edges 
29a (relative the edges 21a, 22a), 30a (relative the edges 22a, 23a), 31a 
(relative the edges 23a, 24a), and 32a (relative the edges 24a, 25a). In 
this way, the ribs 27-32 are integrally connected to the fins 21-26, 
thereby reinforcing the fins in a vertical direction. Due to the fact that 
both the fins 21-26 and the ribs 27-32 are quite thin, these components 
add far less mass behind the face plate 18 than if solid. 
Since it is planned that the face plate 18 and the various fins 20-26 and 
the ribs 27-32 be cast, a tubular boss 34 can be formed during the casting 
procedure. The boss 34 is then drilled so as to provide a bore 36 
(although the bore appears eliptical in FIG. 7 owing to the inclined axis 
of the boss 34). The bore 36 is reamed with a tapered reamer so as to 
impart a slight taper thereto. Thus, the lower end of the shaft 16, which 
is also tapered, can be received in the bore 36 and held through the 
agency of a set screw 40 (FIG. 3). 
As can be understood from FIG. 7, the face plate 18 contains therein a pair 
of counterbored holes at 42 and 43. Each hole 42, 43 has a threaded 
portion 44, an intermediate shoulder 45 and an unthreaded portion 47. In 
this way, a pair of cup-shaped inserts 48 and 49 can be mounted in the 
holes 42 and 43, respectively. Each insert 48 and 49 has a closed end 50 
containing therein a pair of spanner wrench holes 51, a threaded flange 52 
and an internally threaded recess 53. It will be recognized that the 
threaded flange 52 is received in the threaded portion 44 and sufficient 
tightening of the two inserts 48 and 49 will cause their respective 
flanges 52 to bear against the shoulder 45. When this is achieved, then 
the closed end 50 is flush with the front or striking surface of the face 
plate 18. Either or both of the recesses 53 of the inserts 48 and 49 
contains a quantity of heavy metal 54, such as lead or a predetermined 
number of tungsten alloy slugs. The amount of heavy metal 54 will enable 
the golfer to vary the toe and heel weight balance for the proper weight 
distribution best suited for his style of golf. 
To prevent the foamed plastic referred to below from entering the rear of 
the holes 42 and 43 during the molding operation, the rear ends of the 
holes 42, 43 are suitably plugged. As can be discerned in FIG. 7 the back 
side of the face plate 18 is formed with rearwardly projecting integral 
sleeves 55 having closed ends 56. Care must be exercised in drilling the 
holes 42 and 43 not to drill completely through; otherwise, the aluminum 
or magnesium, as the case may be, forming the closed ends 56 would be 
removed by the drill and would allow foamed plastic, while still molten, 
to fill or partially fill, the holes 42, 43. 
In order to impart the requisite aerodynamic characteristics to the club 
head 12, the face plate 18 and its seven fins 20-26 have molded thereabout 
a matrix 60 of rigid foamed plastic, polyurethane having been found to be 
particularly suitable since it has a density less than the aluminum or 
magnesium used for the face plate 18, the various fins 20-26 and the ribs 
27-32. Actually, foamed polyurethane has only 1/10th the weight of 
aluminum and 1/6th the weight of magnesium. The rigid foamed plastic 60 
extends rearwardly from the upper edge, the lower edge and the toe and 
heel edges of the face plate 18 and completely encases the fins 20-26, as 
is believed from FIGS. 1, 4 and 5. 
In order to impart additional strength to the club head 12 where the hosel 
14 merges into what has been referred to as the matrix portion of the head 
12, a section of fiberglass mat 62 is placed in the mold when forming the 
head 12, this mat appearing in section in FIG. 3. 
Recapitulating, it will be appreciated, particularly from FIG. 2, owing to 
the low density of the polyurethane matrix 60, that most of the mass is 
near the back side of the face plate 18. While the foamed polyurethane 
matrix 60 constitutes the greatest volume of the head 12, it is quite 
lightweight, as has already been explained. Without the heavy metal 54 
(lead or tungsten alloy), the center of gravity, as viewed in FIG. 2, 
would be somewhat to the left or rearwardly of the plane in which the 
sectional view along the line 3--3 is taken which plane contains the 
centerline of the shaft 16. However, the introduction of the high density 
metal 54 by means of the inserts 48 and 49 will move the center of gravity 
to the right or toward the face plate 18. Not only does the heavy metal 54 
bring the center of gravity substantially along the axis of the shaft 16, 
but the capability of having more weight in either the insert 48 or 49 
will enable the golfer to vary the balance in a toe-to-heel direction. In 
other words, the golfer can readily effect a shifting of the center of 
gravity from front to rear or from toe to heel so as to best suit his 
particular game. It should be recognized that the appreciable spacing of 
the inserts 48 and 49 from each other, and more importantly from a plane 
(which contains the ribs 27-32) perpendicular to the striking surface 19 
of the face plate 18 which plane passes through the head's center of 
gravity, provides a maximum moment of inertia. This broadens or widens the 
effective striking area, commonly known as the "sweet spot.