BACKGROUND OF THE INVENTION
[0001] In lofting a golf ball out of a trouble spot, such as rough or a sand trap, it is
customary to use an iron, sand wedge, or the like, with considerable mass in the head
to provide the necessary inertia and overcome resistance. The ball is usually struck
in a downward direction to impart a back spin to retard rolling on the green and is
lofted out by continued motion of the club, the head usually striking the ground immediately
after contacting the ball. When the leading edge of the head strikes the ground surface
or cuts through grass, the sharp leading edge has a tendency to dig into the turf,
greatly reducing the power of the blow and including the possibility of deflecting
the club from the desired path.
[0002] Ribbing or corrugation of the lower surface of the head has been used to reduce contact
area, but there is still a large surface which must be forced through obstacles and
the results have not been very satisfactory.
[0003] A wood with a pronounced curvature in the sole has been developed for use in the
rough or on the fairway, but does not have sufficient mass for good penetration. In
weighting a wood the weight is usually centrally located behind the striking point
and the weight distribution in the head is not particularly good. Additionally a wood
with a sole shaped like a single keel of a boat has been produced. However, this has
a sharp leading edge which encourages penetration and greatly reduces the continued
power of the swing.
SUMMARY OF THE INVENTION
[0004] The golf club head described herein is a wood with the cutting advantages of an iron
or fairway wood, combined with the skidding advantage of a sand iron. A wood type
head is provided with a metal sole plate extending over the lower surface of the head
and constituting about 55% of the total weight of the head. The mass is concentrated
in the lower portion of the head, which lowers the center of mass and increases inertia
and driving power. The weight is also spread to the edges of the wood for improved
weight distribution and balance.
[0005] To improve stability the sole plate has a pair of spaced parallel runners of large
cross section extending from front to rear, one rib being near the toe and the other
adjacent the heel of the sole. The runners are generally semi-circular in cross section
and extend well below the lower face of the sole plate. The leading faces of the runners
are inclined downwardly and rearwardly to act as skids and slid through and over the
ground surface with minimum penetration. In grass the resistance is also reduced since
the runners keep the body of the head above the surface and the full width of the
leading edge does not penetrate so deeply into the grass. On the fairway the head
has the characteristics of a wood, but the added weight of the sole plate, with the
low center of mass and good weight distribution, improves the driving power and control
of the club.
[0006] The primary object of this invention, therefore, is to provide a new and improved
golf club head.
[0007] Another object of this invention is to provide a wood having a metal sole plate with
a pair of large runners projecting below the plate to act as skids when the head strikes
the ground.
[0008] Another object of this invention is to provide a wood with a metal sole plate which
extends over the lower surface of the head and constitutes at least half the weight
of the head.
[0009] A further object of this invention is to provide a wood having a low center of mass
with the weight distributed over the sole.
[0010] Other objects and advantages will be apparent in the following detailed description,
taken in conjunction with the accompanying drawing, in which:
Figure 1 is a perspective view of the golf club head.
Figure 2 is an end view taken from the toe end of the head.
Figure 3 is a side elevation view of the striking face of the head.
Figure 4 is an underside view of the head.
Figure 5 illustrates the striking action of the head. DESCRIPTION OF THE PREFERRED
EMBODIMENT
[0011] The golf club head 10 has a wood body 12, with a shaft 14, striking face 16 and a
sole 18. The configuration can vary considerably, that shown being typical.
[0012] Sole 18 is slightly convex and inset into the sole is a metal sole plate 20, which
gives the club its unique characteristics. The sole plate 20 can be manufactured in
several ways but is preferably made by investment casting for precision and smooth
finish, and has sufficient mass to constitute about 55% of the total weight of the
head. As illustrated, the sole plate has cut out portions 22 and 24 at the toe and
heel, respectively, to key into comparably shaped socket portions cut in body 12 for
precise alignment. Except for the cut out portions the sole plate extends over substantially
the entire lower surface or sole of the body and follows the convex contour of the
sole. The weight is thus well distributed across the head but is concentrated in the
lower portion, resulting in a low center of mass for the head.
[0013] The sole plate 20 has a pair of spaced parallel runners 26 and 28 projecting downwardly
and extending from front to rear across the full width of the plate. Runner 26 is
positioned adjacent the toe portion of the head and runner 28 adjacent the heel portion.
The runners are substantially semi-circular in cross section and are quite large compared
to ribbed or grooved structures which have been used.
[0014] While dimensions of the runners may vary, the large size relative to the size of
the head is important. In the example illustrated, the runners are about 0.30 inch
deep and 0.55 inch wide, with a spacing between centers of about 1.25 inches. The
leading faces 30 and 32 of runners 26 and 28, immediately below the leading edge 34
of the sole plate, are inclined downwardly and rearwardly at about 35 degrees from
the vertical, or 55 degrees to the horizontal lower surfaces of the runners. The rear
portion of the sole plate and runners can be contoured to fit the configuration of
the body 12. Sole plate 20 is secured to the body 12 by suitable means such as screws
36, which are inserted through the runners 26 and 28. The heads of the seated screws
are finished to blend smoothly into the contours of the runners.
[0015] A portion of a typical stroke is illustrated in Figure 5. The approaching head 10A
is on a downward swing about to enter the grass 38. The head strikes the ball 40 in
a slightly downward direction to apply a back spin, which retards rolling of the ball
of the green. As shown, the head is slightly above the ground surface 42 at the point
of impact, but could actually contact the ground. When ground contact is made the
inclined leading face 30 of runner 26, and face 32 of runner 28, act as skids and
cause the head to be deflected along the surface with minimum penetration. Even if
the runners do penetrate the ground to any extent, their cross sectional area is much
less than the entire leading edge area of the head and resistance is minimized. In
the follow through portion of the stroke, indicated at 10B, the head slides along
the ground on the runners and then lifts away, as the ball is lofted from the ground.
[0016] In grass the leading edge of the head is kept above the ground surface by the runners,
so that the full width of the leading edge does not penetrate deeply to the base of
the grass. This also minimizes friction or drag on the head.
[0017] In stroking out of a sand trap the sand tends to pack ahead of the runners, and the
inclined leading faces of the runners ride up and out of the sand.
[0018] On the fairway the head is used as a wood, but has the advantage of greater weight
and good balance for driving power and improved trajectory of the ball. The runners
minimize penetration of the turf and tend to stabilize and track the head when it
contacts the ground.
[0019] The head is thus a multi-purpose wood which can be used on the fairway or in trouble
spots, with advantages and desirable characteristics of both a wood and an iron. Due
to the deflecting skid action of the large runners the head causes a minimum divot
and stresses on the club are reduced.
[0020] Having described my invention, I now claim:
1. A golf club head, comprising:
a wood body having a front striking face, a lower sole with a toe portion and a heel
portion, and means for attachment to a shaft;
a metal sole plate fixed to said sole and having a pair of spaced parallel runners
projecting downwardly therefrom and extending from front to rear across the sole plate;
said sole plate having a leading edge below said striking face;
and said runners having leading faces inclined downwardly and rearwardly from said
leading edge.
2. A golf club head according to claim 1, wherein said sole plate extends over the
major portion of said sole.
3. A golf club head according to claim 1, wherein the weight of said sole plate constitutes
at least 50% of the total weight of the head.
4. A golf club head according to claim 1, wherein said sole plate extends over a major
portion of said sole and constitutes approximately 55% of the total weight of the
head.
5. A golf club head according to claim 1, wherein one of said runners is adjacent
said toe portion and the other is adjacent said heel portion.
6. A golf club head according to claim 5, wherein each of said runners is substantially
semi-circular in cross section, with a depth of about 0.30 inch and a width of about
0. 55 inc.
7. A golf club head according to claim 6, wherein said runners are spaced apart approximately
1. 25 inches between cente rs.
8. A golf club head according to claim 1, wherein said leading faces are inclined
at approximately 55 degrees to the lower surfaces of the respective runners.