U.S. patent application number 10/771963 was filed with the patent office on 2004-08-12 for golf club set with variable thickness and/or density face inserts.
This patent application is currently assigned to The Top-Flite Golf Company. Invention is credited to Mahaffey, Steven J., Roach, Ryan L..
Application Number | 20040157677 10/771963 |
Document ID | / |
Family ID | 27668373 |
Filed Date | 2004-08-12 |
United States Patent
Application |
20040157677 |
Kind Code |
A1 |
Roach, Ryan L. ; et
al. |
August 12, 2004 |
Golf club set with variable thickness and/or density face
inserts
Abstract
A set of golf clubs is characterized by club heads having
striking face inserts at least one of which varies in thickness,
density, and/or material from the other inserts so that the heads
have different centers of gravity. Preferably the long irons in the
set have a lower center of gravity (because of thinner or less
dense inserts) to increase the trajectory of a struck golf ball.
The short irons have a higher center of gravity to reduce the
trajectory of a struck golf ball.
Inventors: |
Roach, Ryan L.;
(Northampton, MA) ; Mahaffey, Steven J.;
(Belchertown, MA) |
Correspondence
Address: |
LAW OFFICE OF LAWRENCE E. LAUBSCHER, JR.
1160 SPA ROAD, SUITE 2B
ANNAPOLIS
MD
21403
US
|
Assignee: |
The Top-Flite Golf Company
Chicopee
MA
|
Family ID: |
27668373 |
Appl. No.: |
10/771963 |
Filed: |
February 4, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10771963 |
Feb 4, 2004 |
|
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10228025 |
Aug 26, 2002 |
|
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60356802 |
Feb 14, 2002 |
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Current U.S.
Class: |
473/290 |
Current CPC
Class: |
A63B 53/0416 20200801;
A63B 60/00 20151001; A63B 53/0462 20200801; A63B 53/047
20130101 |
Class at
Publication: |
473/290 |
International
Class: |
A63B 053/00 |
Claims
What is claimed is:
1. A set of golf clubs having heads of progressively increasing
loft, each of the heads comprising (a) a body having top, bottom,
toe and heel portions and a striking face area containing a recess;
(b) an insert secured within said recess, an outer surface of said
insert being substantially flush with a non-recessed portion of
said striking face area; and (c) at least one of the thickness and
density of said inserts increasing within the set of golf clubs as
the loft of a club increases, whereby the mechanical properties of
individual clubs within a set of clubs can be altered to enhance
the performance of the clubs.
2. A set of golf clubs as defined in claim 1, wherein at least one
of said inserts is formed of a material different from said other
inserts.
3. A set of golf clubs as defined in claim 1, wherein said clubs
having successive increases in loft are arranged in groups, said
inserts within said groups having the same thickness and
density.
4. A set of golf clubs as defined in claim 3, wherein a first group
of clubs comprises long irons having an insert thickness of
0.09-0.13 inch.
5. A set of golf clubs as defined in claim 4, wherein a second
group of clubs comprises mid-irons having an insert thickness of
0.13-0.18 inch.
6. A set of golf clubs as defined in claim 5, wherein a third group
of clubs comprises short irons having an insert thickness of
0.19-0.27 inch.
7. A set of golf clubs as defined in claim 3, wherein a first group
of clubs comprises long irons having an insert formed of a first
material.
8. A set of golf clubs as defined in claim 7, wherein a second
group of clubs comprises mid-irons having an insert formed of a
second material having a greater density than said first
material.
9. A set of golf clubs as defined in claim 8, wherein a third group
of clubs comprises short irons having an insert formed of a third
material having a greater density than said second material.
10. A set of golf clubs as defined in claim 1, wherein said insert
and said body are formed of the same material.
11. A set of golf clubs as defined in claim 1, wherein at least one
of said inserts has one of a thickness and density which varies
from a bottom portion to a top portion thereof.
12. A set of golf clubs as defined in claim 11, wherein at least
one of said inserts is thicker at the top than at the bottom.
13. A set of golf clubs as defined in claim 11, wherein at least
one of said inserts is thicker at the bottom than at the top.
14. A set of golf clubs as defined in claim 1, wherein at least one
of said inserts is formed of different materials from a bottom
portion to a top portion thereof.
15. A set of golf clubs as defined in claim 14, wherein said
material in said bottom portion is more dense than a material in
said top portion.
16. A set of golf clubs as defined in claim 14, wherein said
material in said top portion is more dense than a material in said
bottom portion.
Description
[0001] This application claims the benefit of U.S. provisional
application No. 60/356,802 filed on Feb. 14, 2002.
BACKGROUND OF THE INVENTION
[0002] The mechanical properties or characteristics of a golf club
include the center of gravity and moment of inertia. These
properties influence the performance of the club and the resulting
flight of a struck golf ball. For example, a lower center of
gravity creates a higher trajectory than a comparable club with a
higher center of gravity. In addition, a club having a more
rearward center of gravity is more forgiving when balls are struck
outside the center or sweet spot of the striking face. A physical
measure of the forgiveness of a club head is its moment of
inertia.
[0003] The present invention relates to a set of golf clubs having
variable thickness and/or density face inserts to alter the
mechanical properties of the clubs throughout the set.
BRIEF DESCRIPTION OF THE PRIOR ART
[0004] Iron-type golf clubs with face inserts are well known in the
patented prior art. The Mahaffey et al. Pat. Nos. 5,766,094,
5,827,131 and 6,074,309, for example, disclose golf club heads with
laminated striking face inserts which contain cavities and/or
laminations so that the inserts have a reduced weight relative to
prior inserts, whereby more weight can be shifted to the perimeter
of the clubs.
[0005] While the prior golf clubs with striking face inserts
operate satisfactorily, they do not have any effect on the center
of gravity of the clubs within a set since all of the inserts have
the same characteristics. It is known in the art, however, to add
weights to the sole or back portion of a club head to alter its
center of gravity. This increases the manufacturing cost of the
head however and is difficult to correlate throughout a set of
clubs.
[0006] The present invention was developed in order to overcome
these and other drawbacks of the prior art by providing a set of
golf club heads with variable face inserts to enhance the
mechanical properties of the club heads.
SUMMARY OF THE INVENTION
[0007] Accordingly, it is a primary object of the invention to
provide a set of golf clubs having heads of progressively
increasing loft throughout the set. Each of the heads includes a
body having top, bottom, toe and heel portions and a striking face
area containing a recess. An insert is secured within the recess
and the thickness and/or density of the inserts increases within
the set of clubs as the loft of a club increases. This results in a
lower center of gravity for the long irons and a higher center of
gravity for the short irons to improve the trajectory of a golf
ball when struck by the clubs.
[0008] According to a further object of the invention, the insert
and the body of each club are formed of different materials.
Moreover, the inserts in the clubs within a set of clubs may also
be formed of different materials to alter the density of the
inserts throughout the set.
[0009] According to another embodiment of the invention, the
thickness and/or density of an insert is varied from the bottom of
the insert to the top of the insert. In addition, the materials
used in an insert may also differ from the bottom portion to the
top portion thereof to change the weight distribution within the
insert.
BRIEF DESCRIPTION OF THE FIGURES
[0010] Other objects and advantages of the invention will become
apparent from a study of the following specification when viewed in
the light of the accompanying drawing, in which:
[0011] FIG. 1 is an end view of a long iron of a set of golf clubs
according to the invention;
[0012] FIG. 2 is an exploded front perspective view of the iron of
FIG. 1;
[0013] FIG. 3 is an end view of a mid-iron of a set of golf clubs
according to the invention;
[0014] FIG. 4 is an exploded front perspective view of the iron of
FIG. 3;
[0015] FIG. 5 is an end view of a short iron of a set of golf clubs
according to the invention;
[0016] FIG. 6 is an exploded front perspective view of the iron of
FIG. 5;
[0017] FIGS. 7 and 8 are end views of differently tapered inserts,
respectively, for a golf club head according to the invention;
and
[0018] FIG. 9 is a perspective view of an insert formed of
different materials according to the invention.
DETAILED DESCRIPTION
[0019] A set of golf club irons includes long, mid, and short
irons. Typically, and for purposes of the invention, the long irons
comprise irons numbered 1, 2, 3 and 4 which have lofts ranging from
approximately 16.degree. for a 1-iron to 24.degree. for a 4-iron.
The mid-irons include irons numbered 5, 6, 7 and 8 and have lofts
from 26.degree. for a 5-iron to 38.degree. for an 8-iron. The short
irons include a 9-iron, pitching wedge, sand wedge and one or more
lob wedges having lofts from 42.degree. for a 9-iron to 60.degree.
for a lob wedge.
[0020] FIGS. 1 and 2 show a long iron 2 (i.e., a 1, 2, 3, or 4
iron) according to the invention. The iron includes a body 4 having
top 6, bottom 8, toe 10 and heel 12 portions and a striking face
area containing a recess 14. The body is made of any suitable
material such as forged carbon steel, investment cast stainless
steel, or hardened polymer or synthetic plastic material. Around
the perimeter of the recess is a ledge 16 against which an insert
20 rests when the insert is secured within the recess. The insert
may be secured to the body by any suitable means such as welding or
crimping so that the striking face 22 of the insert is
substantially flush with a non-recessed portion of the striking
face area of the body.
[0021] The insert 22 has a thickness t.sub.1 from front to back
which is uniform throughout the insert. The thickness is between
0.09 and 0.14 inch, and preferably 0.11 inch. The insert may be
formed of the same material as the body or of a lighter weight hard
metal such as titanium or a fiber reinforced plastic material
(FRP).
[0022] In FIGS. 3 and 4 are shown a mid-iron golf club 102 (i.e., a
5, 6, 7, or 8 iron) including a body 104 and an insert 120. The
structure of the club 102 is similar to the club 2 of FIGS. 1 and 2
but for the difference in loft of the club and a different
thickness t.sub.2 for the insert. More particularly, the thickness
t.sub.2 is greater than the thickness t.sub.1 and is between 0.13
and 0.18 inch.
[0023] In FIGS. 5 and 6 are shown a short iron golf club 202 (i.e.,
a 9 iron, pitching wedge, sand wedge or lob wedge) including a body
204 and an insert 220. The structure of the club 202 is similar to
the clubs 2 and 102 but for the difference in loft of the club and
a different thickness t.sub.3 for the insert. The thickness t.sub.3
is greater than the thickness t.sub.2 and is between 0.19 and 0.21
inch.
[0024] Varying the thickness of the inserts, either on a club by
club basis, or between groups of clubs as identified above, will
allow the center of gravity of the club head to be relatively lower
and more rearward from the striking face in the long irons compared
to the short irons. This is because the thinner inserts in the long
irons are lighter than the thicker inserts in the short irons. A
lower center of gravity in the long irons increases the flight
trajectory of a struck golf ball. Conversely, a higher center of
gravity in the short irons decreases the flight trajectory of a
struck golf ball.
[0025] The distance of the center of gravity of a club head from
the striking face of the insert affects the moment of inertia of
the head. The moment of inertia is taken around the axis of the
head. In the long irons, where the center of gravity is farther
from the striking face, the moment of inertia is greater and the
club is more forgiving. In the short irons, where the center of
gravity is nearer to the striking face, the moment of inertia is
less and the club head is less forgiving and more workable in
executing a golf shot.
[0026] In addition to thickness, another element which affects the
weight of an insert and thus the position of the center of gravity
of the insert is the density of the material from which the insert
is formed. Club heads for long irons preferably have inserts formed
of less dense materials such as titanium for lower weight and a
higher, more rearward center of gravity, whereas club heads for
short irons preferably have inserts formed of more dense materials
such as 1030 carbon steel for a lower more forward center of
gravity. Mid-irons have inserts formed of strong steel such as 17-4
or carpenter alloys.
[0027] While inserts may be made with a variable thickness or a
variable density, they may also be made with a combination of the
two in order to customize the performance of the clubs in a set.
Any combination may be used throughout the set, either within
groups of clubs (i.e., long, mid and short irons) or within
individual clubs. The same applies to different materials for the
inserts. They can be the same or varied throughout the set of clubs
depending on the desired performance.
[0028] Since the inserts can be tailored in thickness, density,
and/or material to the desired weight to reposition the center of
gravity, it is not necessary to supplement the club head with
additional weights in the sole or other regions of the club head
body. Avoiding additional weighting reduces the cost of manufacture
and provides consistent performance. However, weights can be used,
such as by custom club fitters, in order to satisfy the needs of a
particular player.
[0029] Referring now to FIG. 7, an alternate embodiment for an
insert 320 is shown. In this insert, the thickness progressively
increases from the bottom to the top of the insert. That is, the
bottom thickness t.sub.4 is less than the top thickness t.sub.5.
Such a configuration raises the center of gravity. Conversely, an
insert 420 which is thicker at the bottom than at the top such as
shown in FIG. 8 would lower the center of gravity.
[0030] A further embodiment of a club head insert 520 is shown in
FIG. 9. This insert is formed of different materials having
different densities in order to adjust the center of gravity of the
head in which the insert is used. The embodiment illustrated
comprises three materials 540, 542, and 544, although any number
may be provided. In a preferred embodiment, the lower material 540
is heavier steel, the upper material 544 is lighter titanium, and
the middle material 542 comprises a transition area with a density
between titanium and steel. This insert is characterized by more
weight at the bottom for a lower center of gravity of the club
head, i.e., for use in long irons. Alternatively, by reversing the
materials, an insert with more weight toward the top is provided
for a higher center of gravity of the club head, i.e., for short
irons.
[0031] While the preferred forms and embodiments of the invention
have been illustrated and described, it will be apparent to those
of ordinary skill in the art that various changes and modifications
may be made without deviating from the inventive concepts set forth
above.
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