U.S. patent number 3,897,065 [Application Number 05/438,281] was granted by the patent office on 1975-07-29 for golf club head with improved sole and toe portions.
Invention is credited to Karsten Solheim.
United States Patent |
3,897,065 |
Solheim |
July 29, 1975 |
Golf club head with improved sole and toe portions
Abstract
A trailing portion of the sole of a golf club head is beveled
upwardly relative to a horizontal plane to form a ridge along the
sole. The sole of each club of a set is at a progressively greater
angle relative to a vertical plane passing through the axis of the
club shaft and parallel to the leading edge of the club head along
a central portion of the striking face of the golf club head, and
the progression from club to club of the set is in the order of
increasing loft angle. A trailing surface portion of the toe and
heel is similarly beveled rearwardly and inwardly toward each other
to form toe and heel ridges that blend with the sole ridge. The toe
and heel are also beveled forward of the ridge in the direction of
the striking face.
Inventors: |
Solheim; Karsten (Phoenix,
AZ) |
Family
ID: |
23740012 |
Appl.
No.: |
05/438,281 |
Filed: |
January 31, 1974 |
Current U.S.
Class: |
473/349 |
Current CPC
Class: |
A63B
53/04 (20130101); A63B 53/047 (20130101); A63B
60/00 (20151001); A63B 53/005 (20200801); A63B
53/0433 (20200801) |
Current International
Class: |
A63B
53/04 (20060101); A63B 53/00 (20060101); A63b
053/04 () |
Field of
Search: |
;273/77R,8C,163R,164,167-175 ;D34/5GC,5GH |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Apley; Richard J.
Attorney, Agent or Firm: Lindenberg, Freilich, Wasserman,
Rosen & Fernandez
Claims
What is claimed is:
1. An improved club head for golf clubs of the type commonly
referred to as irons used for hitting a ball into an airborne
trajectory from a fairway comprising a metal blade having a
striking face between a toe and heel, and having a hosel to receive
a shaft at said heel, and a relatively wide sole between said toe
and heel, said sole connecting with said striking face at a leading
edge, a trailing portion of said sole most remote from said leading
edge being beveled rearwardly relative to said striking face and
upwardly relative to a horizontal plane, said horizontal plane
passing through the central portion of said leading edge in a
position normal to a vertical plane, said vertical plane passing
through the axis of said shaft in a position parallel to said
central portion of said leading edge, said sole bevel leaving a
ridge extending from said heel to said toe, said club head having a
trailing surface portion of said toe most remote from said striking
face beveled rearwardly relative to said striking face and inwardly
relative to a plane tangent to said toe and normal to said vertical
plane, and wherein a surface portion of said toe between said
trailing surface portion thereof and said striking face is beveled
forwardly relative to said trailing surface portion and inwardly
relative to said plane tangent to said toe to leave a toe ridge,
said toe ridge blending in with said sole ridge, said toe ridge
being located on said toe approximately midway between leading and
trailing edges thereof and said sole ridge being located on said
sole at least half way from said leading edge of said sole to a
trailing edge of said sole.
Description
BACKGROUND OF THE INVENTION
This invention relates to an improved head for golf clubs, designed
more particularly for use in connection with a correlated golf club
set as disclosed in my U.S. Pat. No. 3,655,188, but having utility
also in connection with other clubs.
In the aforesaid patent there is disclosed a correlated set of golf
clubs of the type commonly referred to as irons. An important
feature of that set is that the angle of the sole of each club of a
set (measured relative to a vertical plane passing through the axis
of the club shaft and parallel to the leading edge of the club head
along a central portion of the striking face of the golf club head)
is correlated with loft and lie. The sole angle for the golf club
of the set having the smallest loft angle is the smallest for the
set and is less than 90.degree., while the sole angle for the golf
club having the greatest loft angle is the greatest for the set and
is greater than 90.degree.. For intermediate golf clubs of the set
in terms of loft, the sole angle is increased as the loft angle is
increased such that for a golf club selected from about the middle
of the set, when arranged in increasing order of loft, has a sole
angle most nearly equal to 90.degree..
An advantage of having the sole angle correlated with the loft in
that manner is that, with a sole angle progressively greater than
90.degree. for golf clubs having a progressively greater loft angle
than the middle club of the set, contact of the sole of the club
with the ground during a stroke will cause the club head to move
upwardly progressively more for a progressively greater loft angle.
The result is that the striking face of the golf club will be in
contact with the ball progressively longer for progressively
greater loft in order to provide progressively more back spin on
the ball. This is desirable with golf clubs of higher loft used on
approach shots onto the putting green.
Golf clubs of progressively lower loft than the one at the middle
of the set are used more often for long shots off the tees and the
middle of the fairway, when distance is more important than
position, rather than for approach shots. Back spin is usually not
desired for long shots. Instead, it is desired that the ball be
allowed to run on the fairway toward the green. Therefore, golf
clubs of progressively smaller loft than the middle club of a
correlated set are provided with sole angles progressively less
than 90.degree. when made in accordance with my aforesaid
patent.
At impact, the ball is flattened out against the face of the club.
Thereafter, due to elasticity, the ball begins to resume its round
shape, thus propelling itself in a direction very nearly normal to
the club face (assuming no spin about a vertical axis of the ball).
It is during this period of propulsion that the feature of a
correlated sole angle has its greatest effect because the greater
the loft the greater the "bounce" of the club head and, therefore,
the greater the period of contact with the ball. However, the swing
of the golf club should not stop when the ball leaves the club
face. For a perfect swing, the golfer must follow through smoothly
after impact. It would be desirable to provide a configuration for
the club head which facilitates the "follow through" without
detracting from the performance of the club in other respects,
particularly the correlated bounce effect when it is provided.
As just noted, the elasticity of the ball propells it in a
direction that is nearly normal to the striking face, but not quite
because at the moment of impact, the golf club head is cutting
across a line in the direction of the intended line of flight,
i.e., across a line on the ground in a direction normal to the club
head at the moment of impact, assuming a stroke with the face of
the club square and not "open" or "closed" (turned clockwise or
counterclockwise by a right handed golfer) deliberately for an
intentional hook or slice. The club head cuts across from the other
side of that line relative to the golfer to the near side of the
line. The fact that the club head is cutting across can be verified
by observing the sole of any golf club that has been extensively
used by a consistent golfer. It will be marked with scratch lines
that are off from a direction normal to the club face by a small
angle. It would be desirable to provide a configuration for the toe
of the club head which will facilitate the follow through and at
the same time permit effectively extending the length of the club
head from the heel to the toe without altering the size or shape of
the striking face. This has the effect of distributing more weight
further out on the toe to maximize the size of the "sweet
spot".
SUMMARY OF THE INVENTION
In accordance with the present invention in its broadest aspects, a
trailing portion of the sole of a golf club of the iron type is
beveled upwardly relative to a horizontal plane to form a ridge
along the sole. The trailing portion refers to a substantial
portion of the sole (at least one-third the width of the sole from
the toe to the heel) farthest away the leading edge of the club
head, the leading edge being where the striking face joins the sole
of the golf club. The end of the toe is similarly beveled
throughout in the trailing surface portion thereof by a small acute
angle relative to a normal to the striking face. That bevel in the
trailing portion of the toe forms a ridge that blends in with the
ridge on the sole where the sole turns upwardly to merge with the
toe end. The leading surface portion of the end of the toe, between
the ridge and the striking face, is also beveled by a small acute
angle in a direction opposite the bevel in the trailing portion of
the toe end of the club head to form a ridge that blends with the
sole ridge. The bevel in that leading portion of the end of the toe
is selected to be approximately equal to the angle by which the
club head cuts across a line normal to its striking face at the
moment of impact during a normal golf swing. The heel end is
similarly beveled in leading and trailing portions to form a ridge
that blends with the sole ridge.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a rear view of a No. 5 iron.
FIG. 2 is a front (toe) end view of the No. 5 iron of FIG. 1.
FIG. 3 is a front (toe) end view of a No. 3 iron.
FIG. 4 is a bottom (sole) view of the No. 5 iron of FIG. 1.
FIG. 5 is a front (toe) end view of a No. 9 iron.
FIG. 6 is a front (toe) end view of a No. 11 iron.
DESCRIPTION OF A PREFERRED EMBODIMENT
Referring to the drawings, selected clubs of a set correlated in
accordance with my aforesaid U.S. Pat. No. 3,655,188 are shown. The
clubs selected are the Nos. 3, 5, 9 and 11. By themselves, they
constitute a "short set", which is all that some golfers carry,
although it is more customary to carry a more complete set, usually
clubs numbered 2 or 3 through 11, and sometimes including a No. 1.
This is, of course, besides the woods customarily carried.
The No. 5 iron shown in FIGS. 1 and 2 will first be described as
representative of the set. It comprises a head 10 having a hosel
11. A shaft 12 (shown broken away) is rigidly attached to the hosel
as an extension thereof in the usual manner. The shaft extends at
an angle C measured in a vertical plane passing through the axis 13
parallel to the central portion of a leading edge 14 (FIG. 2) of a
planar striking face 15. The angle c is commonly defined as the lie
of the club, is measured from a horizontal plane that is
perpendicular to the vertical plane that passes through the central
portion of the leading edge 14. The horizontal and vertical planes
are represented by lines H and V in FIGS. 1 and 2. The horizontal
plane is normal to the plane of the paper in both instances, and
the vertical plane is parallel to and normal to the plane of the
paper in respective FIGS. 1 and 2.
The loft angle A of the club is measured as shown in FIG. 2 from
the vertical plane to the plane of the striking face 15. That angle
is about 28.degree. for a No. 5 iron, but may differ among
manufacture by a few degrees. The lie, angle C, is about
61.degree., but again may differ among manufactures. What is
consistent among all manufactures is that lie is increased as loft
is increased in irons from No. 1 through 9. In irons of greater
loft, the same lie is usually maintained as for a No. 9.
If all clubs of a set are arranged in increasing order of loft, the
central club in the group from No. 1 through No. 9 is the No. 5 and
may therefore be referred to as a midrange club. The remaining
clubs 10 and 11 are specialty clubs commonly referred to as sand
and pitching wedges, but are nevertheless to be correlated with
loft as to a sole angle in accordance with my aforesaid patent.
However, the choice of the No. 5 as the midrange club is not
essential; the No. 6 iron could, for example, be selected as the
"midrange" club.
In accordance with my prior patent, golf clubs of the set arranged
in increasing order of loft angle are provided with a progressively
greater sole angle, where the sole angle is an angle measured from
the vertical plane to a sole plane S tangent to the sole 16 and
parallel to the central portion of the leading edge 14 of the club
head. In the case of the midrange club, the sole angle is selected
to be equal to 90.degree., or very nearly so, such that the angle
between the horizontal plane and the sole plane is equal to or
substantially equal to 0.degree. as shown in FIG. 2. For irons of
smaller loft than the loft of the midrange club, the sole angle is
less than 90.degree. as shown in FIG. 3 for a No. 3 iron. The
complementary angle B is shown for convenience, it being understood
that the sole angle is 90.degree. .+-. B. Since the angle B is
negative for a club of smaller loft than the midrange club as
shown, the sole angle is by this designation less than 90.degree..
For a club of greater loft than the midrange club, the angle B is
positive for a sole angle greater than 90.degree., as shown in
FIGS. 5 and 6 for the No. 9 and No. 11 irons.
The improvement over my prior invention with respect to the sole
angle is a bevel in the trailing portion 16' of the sole 16 which
leaves a ridge 17 extending from the toe 18 to the heel 19
everywhere approximately midway between the leading edge 14 and the
trailing edge 20 of the sole as shown in FIG. 4 for the midrange
club and passing through the neutral axis of the club head. The
neutral axis is a plumb line from a point at approximately the
middle of the grip (not shown) when the club is suspended from that
point.
The bevel on the sole is preferably a small angle of about
15.degree. as shown by the angle D in FIG. 2. Approximately the
same bevel is provided with respect to the sole 16 for all clubs.
The result of the bevel is to reduce the dragging effect of the
trailing edge as the club head passes through the turf particularly
in the "follow through" after impact with the ball. The bounce
(positive and negative) effect of the sole angles (+B and -B) is
retained to substantially the same advantage as before since that
comes into play mostly before the drag effect would begin to take
effect, i.e., before the trailing portion 16' passes very far into
the turf. Once the trailing portion 16' fully penetrates the turf,
this improvement comes fully into play.
Although this improvement has been shown and described with
reference to a correlated golf club set as disclosed in my prior
patent, it should be understood that the same improvement may be
provided to advantage in golf clubs of other configurations not
having a correlated sole angle, or having a sole angle that is
constant (uniform) for every club of the set (usually equal to
90.degree., except for the wedges of the set, Nos. 10 and 11).
Consequently, the appended claims are intended to include this
improvement in such other configurations.
Another improvement which can be used in conjunction with the
improvement just described, or used independently, concerns the
configuration of the toe. The toe is beveled toward the shaft in a
trailing surface portion 18' by a small acute angle E (about equal
to the bevel of the sole) measured relative to a normal to the
striking face leaving a ridge 21 which merges with the ridge 17 of
the beveled sole at a rounded corner 22 shown in FIG. 1. The
surface portion of the toe between the ridge 21 and the striking
face is beveled by a small acute angle F measured relative to a
normal to the striking face but in the opposite direction.
The acute angle F is selected to be equal to the angle between the
expected direction of swing and the direction in which a normal to
the striking face is pointing at the moment of impact due to the
fact that the average golfer has a swing that cuts across from the
outside to the inside of a vertical plane passing through the ball
center and normal to the club face at the moment of impact, the
outside being the side away from the golfer. This obviously will
vary with different golfers, but will always be on the order of
8.degree.. Consequently, an angle of about 8.degree. would be
adequate for the average golfer. The effect of this bevel is to
terminate the end of the club face with a toe having a surface
parallel to the direction of swing, thus extending the club head at
the toe without increasing the length of the striking face from
heel to toe, and without presenting any added turf resistance to
the motion of the club head during impact. The bevel in the
trailing portion 18' is less important but is nevertheless
significant in decreasing drag.
An additional advantage of this configuration is that it allows
moving additional weight out on the toe, thus lengthening the
"sweet spot." The sweet spot is the area on the striking face which
can be used to strike the ball without producing appreciable torque
due to the moments of force involved in striking the ball on a
point of the striking face not precisely in front of the centroid
of the club head.
In the preferred embodiment shown, the bevel of the surface 16' of
the sole is extended around the heel 19 to provide a rearwardly
beveled surface 19' on the trailing surface portion of the heel 19
to form a ridge 23. The other side of the ridge 23 extending is
beveled up on the heel on the leading surface portion of the heel
19 to provide a surface 19". The advantage of these beveled
surfaces 19' and 19" is to minimize the forces of blades of grass
against heel portions of the club head, particularly the beveled
surface 19", which is on the leading side of the ridge 23 which
extends around the heel 19 and merges with the ridge 17, as shown
in FIG. 4.
* * * * *