U.S. patent number 3,863,932 [Application Number 05/362,004] was granted by the patent office on 1975-02-04 for weighted wood golf club.
This patent grant is currently assigned to Wilson Sporting Goods Co.. Invention is credited to Arthur J. Lezatte.
United States Patent |
3,863,932 |
Lezatte |
February 4, 1975 |
WEIGHTED WOOD GOLF CLUB
Abstract
An improved wood-type golf club having a club head in which a
recess is formed, the recess being filled with an insert, a dense
weighting means within the insert, and a layer of an impact
resistant resin within the insert holding the weighting means
therein, the weighting means being positioned to provide a center
of gravity for the club head which is closer to the leading edge of
the club face than in the absence of the weighting means.
Inventors: |
Lezatte; Arthur J. (Downers
Grove, IL) |
Assignee: |
Wilson Sporting Goods Co.
(River Grove, IL)
|
Family
ID: |
23424304 |
Appl.
No.: |
05/362,004 |
Filed: |
May 21, 1973 |
Current U.S.
Class: |
473/342 |
Current CPC
Class: |
A63B
53/04 (20130101); A63B 60/00 (20151001); A63B
53/0466 (20130101); A63B 2209/00 (20130101); A63B
53/0441 (20200801); A63B 53/0416 (20200801); A63B
53/0458 (20200801); A63B 53/0425 (20200801) |
Current International
Class: |
A63B
53/04 (20060101); A63b 053/04 () |
Field of
Search: |
;273/77R,164,167-175 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Apley; Richard J.
Attorney, Agent or Firm: Hill, Gross, Simpson, Van Santen,
Steadman, Chiara & Simpson
Claims
I claim as my invention:
1. A wood-type golf club comprising a club head having a recess in
the striking area, an insert filling said recess, a dense disk
weighting means within said insert, a layer of an impact resistant
resin within said insert covering one face and at least a portion
of the periphery of said disk, the layer of resin having a smoothly
contoured, uninterrupted surface forming part of the striking face
of said club, the disk weighting means being positioned to provide
a center of gravity for said club head which is closer to the
leading edge of the club face than in the absence of said weighting
means.
2. The golf club of claim 1 in which said weighting means is
positioned so that center of gravity is substantially in the plane
which bisects the shaft of the club.
3. The golf club of claim 1 which includes an annular recess in
said insert forwardly of said weighting means for anchoring said
layer of resin within said annular recess.
4. The golf club of claim 1 in which said insert includes an
angular taper in said recess for locking said layer of resin
therein, said recess having a larger diameter at its base than at
its striking face.
5. The golf club of claim 1 in which said resin is an epoxy
resin.
6. A wood-type golf club comprising a club head having a
wedge-shaped recess therein in the striking area, a wedge-shaed
insert received within said recess, said insert having a bore with
a relatively shallow recess at its innermost extremity, a weighting
disc overlying and closing off said shallow recess, a layer of
adhesive in said shallow recess securing said disc thereagainst,
said bore in said insert having a flared portion of increased
diameter spaced from said striking face, and a layer of impact
resistant resin filling said bore about said disc and having a
large diameter radius surface forming the striking area of said
club.
7. The golf club of claim 6 which includes an annular groove in
said insert between said shallow recess and said striking face for
receiving said resin in locking engagement.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is in the field of wood-type golf clubs having
weighting means which move the center of gravity for the club head
forward and preferably into the plane which bisects the shaft of
the club.
2. Description of the Prior Art
The problem of proper transfer of momentum from a golf club to the
impact of a golf ball is one which has occupied the attention of
golf club manufacturers for many years. The magnitude of the
problem can be appreciated when it is realized that a golf club
head may be moving at a speed in excess of 160 feet per second when
it strikes a ball. The time of impact between the golf club and the
ball has been estimated to be less than one millisecond so that
there is a tremendous amount of energy absorption in a very brief
period of time. In order for this transfer of energy to result in
an adequate movement of the ball in terms of distance and
direction, the effective mass of the club head should be properly
positioned with respect to the area of impact on the ball.
Various weighting means have been suggested in the prior art for
reallocating the mass of the club head, such weighting means
usually taking the form of a heavy metal slug which is located
beneath the sole plate in various positions. It has been found,
however, that the positioning of weights in this manner does not
always result in improving the energy transfer between a golf wood
head and the golf ball. Possibly, this is due to the fact that the
line of action of the centers of gravity of the ball and the club
head are not in line with the theoretical flight path so that an
inefficient collision results between the head and the ball.
SUMMARY OF THE INVENTION
The present invention provides an improved wood-type golf club in
which the club head is provided with a conventional recess in which
an insert is tightly received. The configuration of the insert,
however, differs from conventional inserts in that it has a bore
therein at the inner extremity of which there is a shallow recess.
A weighting disc composed of a dense metal such as a tungsten alloy
or the like overlies and closes off this shallow recess. A layer of
adhesive is provided in the shallow recess to secure the disc
thereagainst. The bore in the insert has a flared portion of
increased diameter spaced from the striking face, and a layer of
impact resistant resin fills this bore about the disc and provides
the striking face at the forward edge of the insert. The golf club
may also be provided with an annular groove in the insert between
the shallow recess and the striking face for receiving an
additional amount of resin to securely lock the impact resistant
resin within the insert.
The procedural steps involved in making the improved golf club of
the present invention consist of positioning the weighting disc
about the shallow recess of the insert and adhesively securing the
two together. This is followed by pouring in an impact resistant
resin into the cavity provided in the recess so that the resin sets
and solidifies about the weighting disc confined therein. The resin
expands slightly on setting, so that it completely fills the recess
in the insert and is locked in place. This final step consists in
grinding or otherwise shaping the striking face of the insert to
conform it to the desired radius of the golf club head.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the invention will be
readily apparent from the following description of certain
preferred embodiments thereof, taken in conjunction with the
accompanying drawings, although variations and modifications may be
effected without departing from the spirit and scope of the novel
concepts of the disclosure, and in which:
FIG. 1 is a fragmentary side elevational view of the improved golf
club of the present invention;
FIG. 2 is a fragmentary front elevational view of the golf club of
the present invention;
FIG. 3 is a fragmentary plan view of the golf club head of the
present invention;
FIG. 4 is an exploded view on an enlarged scale of the insert of
the present invention, with the parts being tilted somewhat for
showing the configuration more specifically; and
FIG. 5 is a fragmentary cross-sectional view on an enlarged scale
of the insert of the present invention in the form in which it is
received within the golf club head.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, reference numeral 10 indicates generally a golf club of
the wood type, the specific club being illustrated being a No. 1
wood although it will be evident that the invention is also
applicable to other wood clubs having different angles of
inclination on the striking faces. The golf club 10 may be composed
of a laminated construction as is common in the prior art and it
includes a head 11 having a striking face 12 of relatively large
radius of curvature, usually on the order of 101/2 inches. Disposed
within a suitable wedge-shaped recess in the striking face 12 is a
wedge-shaped insert 13 which extends from the sole of the club to
the upper portion of the striking face in the conventional manner.
A set of grooves 14 is provided across the insert 13 as well as
across the adjoining portions of the striking face 12 on either
side of the insert 13. The club head 11 also includes a neck
portion 15 which is received within a neck collar 16 which also
receives, at its opposite end, a shaft 17.
The construction of the insert 13, per se, is best illustrated in
FIGS. 4 and 5 of the drawings. As there illustrated, the insert 13
has a relatively deep bore 18 which proceeds inwardly into the
insert 13 from the striking face thereof. An annular groove 19 is
formed in a medial portion of the bore 18 to serve as an additional
locking means for the impact resistant resin which is poured into
the bore, as will be apparent from a succeeding portion of this
description. Inwardly of the annular groove 19, the bore 18 is
outwardly flared as indicated at reference numeral 20 by a few
degrees or so to serve as an additional means for locking the
impact resistant resin within the bore to resist disengagement of
the resin from within the bore.
The innermost end of the bore is formed with a relatively shallow
recess 21 and the bore also has an annular flange surface 22. A
decorative washer 23 composed of brass or the like is positioned
along the annular flange 22 in surrounding relationship to a disc
24 composed of a dense metal such as a sintered, highly dense
compact of tungsten alloy powder. The disc 24 is secured over the
recess 21 by means of a layer of adhesive 25 disposed in the recess
21 as best illustrated in FIG. 5.
After the disc 24 is adhesively secured to the recess 21 by means
of the adhesive 25, and the washer 23 is placed therearound, the
remaining void space is filled by means of an impact resistant
resin layer 26. For purposes of eye appeal, the impact resistant
resin may be transparent material such as an epoxy resin or other
suitable high impact material such as a polycarbonate, a polyester,
or a polyimide resin.
In setting, an impact resistant epoxy resin undergoes a slight
expansion so that the resin may extend beyond the confines of the
striking face of the insert. Any such excess can be removed by
grinding, machining, or other means to provide a striking face 27
having a relatively large radius of curvature such as 101/2 inches
or so. At that time, the grooves 14 can be scribed in the striking
face of the resin 26 as well as in the adjoining portions of the
club head.
The disc 24 is located immediately behind the proper point of
impact on the striking face 27. Referring to FIG. 3, if the insert
13 is made of a completely homogeneous material, that is, without
the combination of the insert and the impact resistant resin, the
center of gravity of the club head will be located at a distance A
from the tangent to the leading edge of the club face, as
illustrated in that figure. With the improvements of the present
invention, however, the center of gravity of the club head lies at
a distance B from the leading edge of the club face and is
substantially in the plane which bisects the shaft 17.
The positioning of the disc 24 also serves to change the moment of
inertia of the club head about its principal axes. These axes are
identified in FIGS. 1 and 3 as the x, y and z axes. The ideal
weight distribution would be such as to increase the moment of
inertia about the center of gravity in the x--z plane, i.e., in a
plane parallel to the ground and passing through the vertical level
of the center of gravity of the club head. With such a weight
distribution, the club head would be the most stable during a swing
and there would be less tendency to hit off-line shots. The
location of the disc 24 in the insert as indicated serves to
increase the moment of inertia in this x--z plane, thereby making
the club head more stable than a conventional head.
To illustrate the effect of positioning the weighting disc in the
center of the face insert, some measurements were made with a No. 1
wood of conventional design. It was found that the center of
gravity of the wood club with a conventional insert existed at a
point which was 1 - 3/16 inches from the leading edge of the sole,
7/8 of an inch vertically from the leading edge, and 9/32 of an
inch behind the axis of the shaft. When the same club was provided
with an insert including a tungsten alloy weighting disc 3/4 of an
inch in outer diameter and 1/8 inch thick, weighing approximately
9/16 of an ounce, the center of gravity of the club head was found
to exist at a point which was 7/8 of an inch from the leading edge
of the sole, 13/16 of an inch vertically from the leading edge, and
only 1/32 of an inch behind the axis of the shaft.
The movement of the center of gravity of the head has been found to
improve significantly the energy transfer between the head of the
club and the golf ball when properly struck. The line of action of
the centers of gravity of the ball and the club head are more
directly in line with the theoretical flight path resulting in a
more efficient collision between the club head and the ball.
Another advantage is achieved in the combined coefficient of
restitution between the ball and the insert. The use of the dense
weighting disc in the hitting area increases the amount of energy
available in a measurable quantity.
By positioning the weighting disc with its centerline coinciding
with the center of the proper hitting area on the striking face,
more mass is concentrated in precisely the region in which it does
the most good. There is a corresponding lesser tendency to have a
component of the impact force at an angle other than normal to the
vertical tangent plane of the ball, so that the tendency to hit
shots off line is somewhat reduced.
It should be evident that various modifications can be made to the
described embodiments without departing from the scope of the
present invention.
* * * * *