U.S. patent number 3,751,035 [Application Number 05/159,133] was granted by the patent office on 1973-08-07 for set of golf irons.
Invention is credited to John W. Lockwood.
United States Patent |
3,751,035 |
Lockwood |
August 7, 1973 |
SET OF GOLF IRONS
Abstract
A set of golf club irons with heads having graduated loft
angles, the striking faces being of the same size and elliptical
shape so that the club head is balanced both vertically and
horizontally about the center of the elliptical driving face, with
a downwardly curved lower front edge to minimize the divot, and a
recess in the rear face creates a sweet spot at the center of the
striking face and a uniform distance from the lower front edge
throughout the set of irons, the minimum thickness of metal at the
sweet spot being also uniform throughout the set of irons since the
recess is a spherical segment, above the sole of the head, having a
constant radius with a center on a line through the center of the
driving face and normal to the plane of the driving face. The
psychological advantage in locating the sweet spot identically in
identical driving faces is obvious since the user can more easily
learn to use all the clubs of the set with heightened
efficiency.
Inventors: |
Lockwood; John W. (La Jolla,
CA) |
Family
ID: |
22571212 |
Appl.
No.: |
05/159,133 |
Filed: |
July 2, 1971 |
Current U.S.
Class: |
473/290 |
Current CPC
Class: |
A63B
53/04 (20130101); A63B 60/00 (20151001); A63B
53/047 (20130101); A63B 53/005 (20200801); A63B
53/0458 (20200801); A63B 53/0408 (20200801) |
Current International
Class: |
A63B
53/04 (20060101); A63B 53/00 (20060101); A63b
053/04 () |
Field of
Search: |
;273/77R,77A,78,8C,164,167-175 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
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371,974 |
|
May 1932 |
|
GB |
|
7,365 |
|
Mar 1912 |
|
GB |
|
Other References
"The Search for the Perfect Swing" by A. Cochran and J. Stobbs;
1968; Library of Congress Catalog Card No. 68-9441; Pertinent pages
207 and 208..
|
Primary Examiner: Pinkham; Richard C.
Assistant Examiner: Apley; Richard J.
Claims
I claim, as my invention:
1. A set of golf irons, comprising:
a plurality of irons, each iron having a head with a different loft
angle wherein said loft angle progressively increases from the
lowest numbered iron to the highest numbered iron and each head
having a front striking face, a rear face and a lower front leading
edge;
the striking faces of the different irons being the same size and
shape;
and the rear face of each iron in said set having therein a recess
in the shape of a spherical segment providing a minimum head
thickness uniform throughout said set and a sweet spot at a uniform
distance from the lower front edge throughout the set.
2. A set of golf irons according to claim 1 wherein said striking
faces are elliptical so that each lower front edge is downwardly
curved to minimize the divot taken by the club in use with the
sweet spot at the center of the ellipse so that the striking face
is symmetrical both vertically and horizontally about said sweet
spot.
3. A set of golf irons according to claim 1 wherein said distance
from the lower front edge is on the order of 1.12 inches.
4. A set of golf irons according to claim 1 wherein each of said
heads has a sole and said recess is above said sole and each sphere
of which said recess is a segment has a radius constant thoughout
the set, the center of which sphere is on a line perpendicular to
said striking face through the sweet spot of said striking
face.
5. A set of golf irons according to claim 4 wherein said radius is
on the order of 1.00 inch and the head thickness at said sweet spot
is on the order of 0.18 inches.
6. A set of golf irons according to claim 1 wherein each iron has a
sole, the rearward portion of said sole beneath said recess is, in
the irons of the set having high loft angles, a plate on the order
of 0.125 inch thick curved in conformity with the corresponding
portion of the elliptical lower front edge of the striking face.
Description
BACKGROUND OF THE INVENTION
Many prior art irons have been developed showing, more or less
incidentally and without correlation, some of the features of my
club construction. For example, some prior art clubs have such
independent features as downwardly curved edges and recessed rear
faces, although not co-ordinated functionally or even structurally.
In other words, the user of prior art clubs, even with beautifully
"matched" sets including wedges, putters and other clubs,
frequently had difficulty in recognizing the exact spot in the
heads which should strike the ball party due to the fact that the
heads or striking faces of the heads were not symmetrical about any
such easily recognized control point. Furthermre many irons tended
to twist even when virtually properly stroked because of
imbalance.
SUMMARY OF THE INVENTION
As claimed, these clubs are the irons in a set of irons, ordinarily
numbered one to nine, and the heads all have the same size and
elliptical shape, each iron has a sole in the rear face of the
irons is a recess having the shape of a segment of a sphere, the
center of the sphere being about 1.18 inches to the rear of the
driving face on a line through the center of the front face,
perpendicular thereto, and the radius is on the order of one inch
so that the minimum head thickness at the resulting sweet spot is
about 0.18 inches, this thickness being constant throughtout the
set. Since the striking face is elliptical the lower front edge
takes a minimum divot with minimum twisting moment, this feature
being heightened by the symmetry of the club about the sweet
spot.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front face view of an iron fashioned according to this
invention, the head and hosel being shown full size and the shaft
being fragmentarily shown;
FIG. 2 is a side elevation view as taken from the right side of
FIG. 1;
FIG. 3 is a sectional view taken on line 3--3 of FIG. 1;
FIG. 4 is a similar sectional view of an iron with a greater loft
angle;
FIG. 5 is a similar sectional view of an iron with a still greater
loft angle;
FIG. 6 is a sectional view taken on line 6--6 of FIG. 2.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
In the drawing three irons of different loft angles are proposed as
representative of a complete set of irons, ordinarily numbered 1 to
9 and variously named. The loft angles are indicated at A as the
difference between the vertical and the driving faces 10, 12 and
14, respectively, of the number 1 iron of FIGS. 1, 2, 3, and 6, the
number 5 iron represented in FIG. 4 and the number 9 iron
represented in FIG. 5.
Each iron will have a shaft, fragmentarily indicated at 16, a hosel
18 and the head which is shown in detail and generally indicated by
the numeral 20 in FIG. 1. It is preferred that the hosel 18 should
emerge from head 20 initially in the general direction of the major
axis of the ellipse defined by the striking face of the club and
then curve upwardly to the shaft 16. The elliptical shape of the
striking faces is important, for balance both vertically and
horizontally is at least optically evidenced thereby and the user
of the clubs is psychologically benefited and assured by the
uniformity in shape and size of the striking faces, the most
obvious protions of the club heads. Two additional assets also may
be mentioned, namely, the elliptical shape provides a nearly
optimum striking area and the curved lower front edge 22 takes a
minimum divot. The striking face proper may of course be striated
as at 24 or otherwise treated in accordance with USGA rules.
The head 20 is generally triangular in vertical cross-section and
the rear faces 24, 26 and 28 are inclined away from the striking
faces so that soles 30, 32 and 34 of graduated, horizontal length
are generated, these soles being substantially horizontal as
indicated. In the irons with greater loft the soles become curved
plates as indicated at 32 and 34 of approximately one-eight inch
thickness, the curvature of course generally following the
curvature of the corresponding portion of said forward lower edge
22 of the elliptical striking face.
A sweet spot 36 of minimum head thickness is provided by forming a
recess as shown at 38, 40 and 42 above the sole 30, 32 and 34,
respectively, this recess being a segment of a sphere and the
spherical radius R is a constant on the order of one inch
throughout the set of irons. The center of curvature for said
recess is located at a distance D to the rear of the striking faces
10, 12, and 14, measured on a line through the sweet spot 36
perpendicular to the striking face. The distance D is on the order
of 1.18 inches in each iron so that the minimum thickness T of the
head at the sweet spot 36 is a uniform thickness on the order of
0.18 inch. The distance H from the sweet spot to the lower front
edge is uniform throught the set and is on the order of 1.12
inches.
Although rather specific dimensions have been set forth above these
measurements should be considered in the context of the important
features of uniformity in size and shape of the driving face,
uniformity or standardization of the sweet spot structure and
location thereof in reference to the standarized driving face and a
balancing of the driving face both vertically and horizontally
about the sweet spot as center.
* * * * *