U.S. patent number RE35,955 [Application Number 08/774,070] was granted by the patent office on 1998-11-10 for hollow club head with deflecting insert face plate.
Invention is credited to Clive S. Lu.
United States Patent |
RE35,955 |
Lu |
November 10, 1998 |
Hollow club head with deflecting insert face plate
Abstract
A head for a golf club includes a body shell, a face plate held
on the body shell for striking the golf ball and an internal
element mounted in the body shell for reinforcing the face plate.
More specifically, the face plate is deflectable from a static
position to a striking position as a result of stress produced when
striking the golf ball. Further, a mechanism is provided for
maintaining a gap between the reinforcing element and the face
plate when the face plate is in a static position so as to provide
a cushioning effect immediately upon striking the golf ball.
.Iadd.The club head having a face plate mounting assembly in the
form of a channel on the body shell, a cooperating lug on the face
plate for receipt in the channel and a mounting flange on the body
shell for capturing the lug within the channel..Iaddend.
Inventors: |
Lu; Clive S. (Hicksville,
NY) |
Family
ID: |
23171202 |
Appl.
No.: |
08/774,070 |
Filed: |
December 23, 1996 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
303249 |
Sep 8, 1994 |
05499814 |
Mar 19, 1996 |
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Current U.S.
Class: |
473/329; 473/342;
473/345 |
Current CPC
Class: |
A63B
53/0466 (20130101); A63B 60/00 (20151001); A63B
53/04 (20130101); A63B 2209/00 (20130101); A63B
53/0416 (20200801); A63B 53/045 (20200801); A63B
53/0425 (20200801) |
Current International
Class: |
A63B
53/04 (20060101); A63B 053/04 () |
Field of
Search: |
;473/329,330,331,342,350,345,346 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
USGA, Rules of Golf, 1989, p. 100..
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Primary Examiner: Pierce; William M.
Attorney, Agent or Firm: Aquilino & Welsh
Claims
I claim:
1. A head for a golf club, comprising:
a body shell;
a face plate held on said body shell for striking a golf ball, said
face plate being deflectable from a static position to a striking
position as a result of stress produced when striking a golf
ball;
an element mounted on said body shell defining a means for
reinforcing said face plate by means of physical engagement with
said face plate when said face plate is in said striking position;
and
means for maintaining a gap between said reinforcing element and
said face plate when said face plate is in said static position
whereby a cushioning effect is provided immediately upon striking
the golf ball.
2. The golf club head set forth in claim 1, wherein said body shell
.Iadd.includes .Iaddend.a cast top, sole and sidewalls.
3. The golf club head set forth in claim .[.2.]. .Iadd.1.Iaddend.,
wherein said face plate is constructed from a material selected
from a group consisting of metals, nonmetals and composites having
a tensile strength of between 40.0-250.0 ksi and a thickness of
between 0.01-0.30 inches.
4. The golf club head set forth in claim .[.3.]. .Iadd.1.Iaddend.,
wherein said reinforcing element includes:
(1) a support plate for engaging said face plate when said face
plate is in said striking position;
(2) an arched backing member; and
(3) spaced ribs for connecting said arched backing member to said
support plate, said arched backing member and ribs serving to
distribute load placed upon said support plate when striking a golf
ball.
5. The golf club head set forth in claim .[.3.]. .Iadd.1.Iaddend.,
wherein said face plate has a minimum yield strength of 40.0 ksi
and a modulus of elasticity of between 10.times.10.sup.3
-20.times.10.sup.3 ksi.
6. The golf club head set forth in claim .[.5.]. .Iadd.1.Iaddend.,
wherein said gap maintaining means includes means for mounting said
reinforcing element to said body shell and means for mounting said
face plate to said body shell, said face plate mounting means
including:
(1) an z-shaped channel on said body shell;
(2) a cooperating z-shaped lug on said face plate for receipt in
said z-shaped channel; and
(3) a bendable mounting flange on said body shell for closing said
z-shaped channel and capturing said mounting lug. .[.
7. The golf club head set forth in claim 5, wherein said
reinforcing element includes:
(1) a support plate for engaging said face plate when said face
plate is in said striking position;
(2) an arched backing member; and
(3) spaced ribs for connecting said arched backing member to said
support plate, said arched backing member and ribs serving to
distribute load placed upon said support plate when striking a golf
ball..].
8. A golf club, comprising the head set forth in claim .[.7.].
.Iadd.1.Iaddend., a flexible shaft having a proximal end and a
distal end, and a grip, said head being connected to said distal
end of said shaft and said grip being connected to said proximal
end of said shaft. .[.9. The golf club head set forth in claim 7,
wherein said gap maintaining means includes means for mounting said
reinforcing element to said body shell and means for mounting said
face plate to said body shell, said face plate mounting means
including:
(1) an z-shaped channel on said body shell;
(2) a cooperating z-shaped lug on said face plate for receipt in
said z-shaped channel; and
(3) a bendable mounting flange on said body shell for closing said
z-shaped
channel and capturing said mounting lug..].10. The golf club head
set forth in claim .[.7.]. .Iadd.1.Iaddend., wherein said gap is
between 0.001-0.30 inches thick. .[.11. The golf club head set
forth in claim 10, wherein said gap maintaining means includes
means for mounting said reinforcing element to said body shell and
means for face plate mounting said face plate to said body shell,
said mounting means including:
(1) an z-shaped channel on said body shell;
(2) a cooperating z-shaped lug on said face plate for receipt in
said z-shaped channel; and
(3) a bendable mounting flange on said body shell for closing said
z-shaped channel and capturing said mounting lug..]..[.12. A golf
club, comprising the head set forth in claim 10, a flexible shaft
having a proximal end and a distal end, and a grip, said head being
connected to said distal end of said shaft and said grip being
connected to said proximal end of said shaft..]..[.13. The golf
club head set forth in claim 2, wherein said reinforcing element
includes:
(1) a support plate for engaging said face plate when said face
plate is in said striking position;
(2) an arched backing member; and
(3) spaced ribs for connecting said arched backing member to said
support plate, said arched backing member and ribs serving to
distribute load placed upon said support plate when striking a golf
ball..]..[.14. The golf club head set forth in claim 2, wherein
said gap is between 0.001-0.30 inches thick..]..[.15. The golf club
head set forth in claim 2, wherein said gap maintaining means
includes means for mounting said reinforcing element to said body
shell and means for mounting said face plate to said body shell,
said face plate mounting means including:
(1) an z-shaped channel on said body shell;
(2) a cooperating z-shaped lug on said face plate for receipt in
said z-shaped channel; and
(3) a bendable mounting flange on said body shell for closing said
z-shaped channel and capturing said mounting lug..]..[.16. A golf
club, comprising the head set forth in claim 2, a flexible shaft
having a proximal end and a distal end, and a grip, said head being
connected to said distal end of said shaft and said grip being
connected to said proximal end of said
shaft..]..[.17. The golf club head set forth in claim 1, wherein
said face plate is constructed from a material selected from a
group consisting of metals, nonmetals and composites having a
tensile strength of between 40.0-250.0 ksi and a thickness of
between 0.01-0.30 inches..]..[.18. The golf club head set forth in
claim 17, wherein said gap is between 0.001-0.30 inches
thick..]..[.19. The golf club head set forth in claim 17, wherein
said gap maintaining means includes means for mounting said
reinforcing element to said body shell and means for mounting said
face plate to said body shell, said mounting means including:
(1) an z-shaped channel on said body shell;
(2) a cooperating z-shaped lug on said face plate for receipt in
said z-shaped channel; and
(3) a bendable mounting flange on said body shell for closing said
z-shaped channel and capturing said mounting lug..]..[.20. A golf
club, comprising the head set forth in claim 17, a flexible shaft
having a proximal end and a distal end, and a grip, said head being
connected to said distal end of said shaft and said grip being
connected to said proximal end of said
shaft..]..[.21. The golf club head set forth in claim 17, wherein
said face plate has a minimum yield strength of 40.0 ksi and a
modulus of elasticity of 10.times.10.sup.3 14 20.times.10.sup.3
ksi..]..[.22. The golf club head set forth in claim 21, wherein
said reinforcing element includes:
(1) a support plate for engaging said face plate when said face
plate is in said striking position;
(2) an arched backing member; and
(3) spaced ribs for connecting said arched backing member to said
support plate, said arched backing member and ribs serving to
distribute load placed upon said support plate when striking a golf
ball..]..[.23. The golf club head set forth in claim 21, wherein
said gap is between 0.001-0.30 inches thick..]..[.24. The golf club
head set forth in claim 21, wherein said gap maintaining means
includes means for mounting said reinforcing element to said body
shell and means for mounting said face plate to said body shell,
said face plate mounting means including:
(1) an z-shaped channel on said body shell;
(2) a cooperating z-shaped lug on said face plate for receipt in
said z-shaped channel; and
(3) a bendable mounting flange on said body shell for closing said
z-shaped channel and capturing said mounting lug..]..[.25. A golf
club, comprising the head set forth in claim 21, a flexible shaft
having a proximal end and a distal end, and a grip, said head being
connected to said distal end of said shaft and said grip being
connected to said proximal end of said shaft..]..[.26. The golf
club head set forth in claim 17, wherein said reinforcing element
includes:
(1) a support plate for engaging said face plate when said face
plate is in said striking position;
(2) an arched backing plate; and
(3) spaced ribs for connecting said arched backing member to said
support plate, said arched backing member and ribs serving to
distribute load placed upon said support plate when striking a golf
ball..]..[.27. The golf club head set forth in claim 1, wherein
said face plate has a minimum yield strength of between 40 ksi and
a modulus of elasticity of between 10.times.10.sup.3
-20.times.10.sup.3 ksi..]..[.28. The golf club head set forth in
claim 27, wherein said reinforcing element includes:
(1) a support plate for engaging said face plate when said face
plate is in said striking position;
(2) an arched backing member; and
(3) spaced ribs for connecting said arched backing member to said
support plate, said arched backing member and ribs serving to
distribute load placed upon said support plate when striking a golf
ball..]..[.29. The golf club head set forth in claim 27, wherein
said gap is between 0.001-0.30 inches..]..[.30. The golf club head
set forth in claim 27, wherein said gap maintaining means includes
means for mounting said reinforcing element to said body shell and
means for mounting said face plate to said body shell, said face
plate mounting means including:
(1) an z-shaped channel on said body shell;
(2) a cooperating z-shaped lug on said face plate for receipt in
said z-shaped channel; and
(3) a bendable mounting flange on said body shell for closing said
z-shaped channel and capturing said mounting lug..]..[.31. A golf
club, comprising the head set forth in claim 27, a flexible shaft
having a proximal end and a distal end, and a grip, said head being
connected to said distal end of said shaft and said grip being
connected to said proximal end of said
shaft..]..[.32. The golf club head set forth in claim 1, wherein
said reinforcing element includes:
(1) a support plate for engaging said face plate when said face
plate is in said striking position;
(2) an arched backing member to said support plate, said arched
backing member and ribs serving to distribute load placed upon said
support plate when striking a golf ball..]..[.33. The golf club
head set forth in claim 32, wherein said gap is between 0.001-0.30
inches thick..]..[.34. The golf club head set forth in claim 32,
wherein said gap maintaining means includes means for mounting said
reinforcing element to said body shell and means for mounting said
face plate to said body shell, said face plate mounting means
including:
(1) an z-shaped channel on said body shell;
(2) a cooperating z-shaped lug on said face plate for receipt in
said z-shaped channel; and
(3) a bendable mounting flange on said body shell for closing said
z-shaped
channel and capturing said mounting lug..]..[.35. A golf club,
comprising the head set forth in claim 32, a flexible shaft having
a proximal end and a distal end, and a grip, said head being
connected to said distal end of said shaft and said grip being
connected to said proximal end of said shaft..]..[.36. The golf
club head set forth in claim 1, wherein said gap is between
0.001-0.30 inches thick..]..[.37. The golf club head set forth in
claim 36, wherein said gap maintaining means includes means for
mounting said reinforcing element to said body shell and means for
mounting said face plate to said body shell, said face plate
mounting means including:
(1) an z-shaped channel on said body shell;
(2) a cooperating z-shaped channel; and
(3) a bendable mounting flange on said body shell for closing said
z-shaped channel and capturing said mounting lug..]..[.38. A golf
club, comprising the head set forth in claim 37, a flexible shaft
having a proximal end an a distal end, and a grip, said head being
connected to said distal end of said shaft and said grip being
connected to said proximal end of said
shaft..]..[.39. A golf club, comprising the head set forth in claim
36, a flexible shaft having a proximal end and a distal end, and a
grip, said head being connected to said distal end of said shaft
and said grip being connected to said proximal end of said
shaft..]..[.40. The golf club head set forth in claim 1, wherein
said gap maintaining means includes means for mounting said
reinforcing element to said body shell and means for mounting said
face plate to said body shell, said face plate mounting means
including:
(1) an z-shaped channel on said body shell;
(2) a cooperating z-shaped lug on said face plate for receipt in
said z-shaped channel; and
(3) a bendable mounting flange on said body shell for closing said
z-shaped channel and capturing said mounting lug..]..[.41. A golf
club, comprising the head set forth in claim 1, a flexible shaft
having a proximal end and a distal end, and a grip, said head being
connected to said distal end of said shaft and said grip being
connected to said proximal end of said
shaft..]..Iadd.42. A head for a golf club including a top wall, a
sole, side walls, and a striking face extending between said top
wall and said sole, comprising:
a body shell having a front face;
a face plate held on said body shell for striking a golf ball, said
face plate including a ball striking surface which is deflectable
from a static position to a striking position as a result of stress
produced when striking a golf ball;
a mounting flange about a periphery of said front face of said body
shell including a channel formed therein; and
a cooperating lug extending from a periphery of said ball striking
surface of said face plate for receipt in said channel of said
mounting flange for securing said face plate to said body shell,
such that said mounting flange and said striking surface of said
face plate form said striking face of said head of said golf
club..Iaddend..Iadd.43. The golf club head set forth in claim 42,
wherein said channel and cooperating lug are
z-shaped..Iaddend..Iadd.44. The golf club head set forth in claim
42, wherein a portion of said mounting flange is
bendable..Iaddend..Iadd.45. A golf club, comprising the head set
forth in claim 42, a flexible shaft having a proximal end and a
distal end, and a grip, said head being connected to said distal
end of said shaft and said grip being connected to said proximal
end of said shaft..Iaddend..Iadd.46. The golf club head set forth
in claim 42, wherein said body shell includes a cast top, sole
and sidewalls..Iaddend..Iadd.47. A method for manufacturing a head
for a golf club including a top wall, a sole, a side wall, and a
striking face extending between said top wall and said sole,
wherein said golf club comprises: a body shell having a front face;
a face plate held on said body shell for striking a golf ball; a
mounting flange about a periphery of said front face of said body
shell including a channel formed therein; and a cooperating lug
extending from a periphery of a ball striking surface of said face
plate, comprising the following steps:
inserting said cooperating lug within said channel of said mounting
flange such that a striking surface of said face plate is
substantially aligned with said front face of said body shell;
and
folding said mounting flange over said cooperating lug to securely
retain
said face plate to said front face of said body
shell..Iaddend..Iadd.48. The method according to claim 47, wherein
said mounting flange is folded over said cooperating lug such that
said mounting flange and said striking surface of said face plate
form said striking face of said head of said golf club..Iaddend.
Description
TECHNICAL FIELD
The present invention relates generally to the field of golf and,
more particularly, to an improved design and construction of a golf
club.
BACKGROUND OF THE INVENTION
Golf is a skill sport wherein a constant goal is to improve ones
level of play. Such improvement may be achieved in two ways. The
first is by improving the ability and skill of the individual
golfer. The second is by improving the performance of the equipment
including both the golf balls and the golf clubs used to strike the
golf balls. The present invention relates to the desire to provide
improved golf clubs characterized by superior weight distribution
that promotes longer, straighter shots even for off-center hits and
improved "feel" that allows for better control of the flight of the
golf ball by the player.
The desire to provide golf clubs exhibiting enhanced performance
and, accordingly, a competitive edge has been a driving force in
the golf club industry for years. Improvements in the design of
golf clubs include "cavity back" irons to provide better weight
distribution and a larger sweet spot for striking the ball and
"metal woods" that allow better weight distribution and
presentation of a larger sweet spot for increases in both
directional accuracy and driving distance.
Despite a large number of significant advances having been made in
golf club design over the years, further improvements in
performance are still desired and are possible. In this regard, one
area of golf club design in ready need of improvement is the club
face and the channeling and distribution of the stress through the
golf club at the moment of and immediately after the impact with
the golf ball. It is to this aspect of golf club design which the
present invention relates.
SUMMARY OF THE INVENTION
Accordingly, it is a primary object of the present invention to
provide a golf club of relatively simple design that is adapted to
provide reliable and dependable performance over a long service
life.
Another object of the present invention is to provide a head for a
golf club incorporating a minimal number of component parts and
utilizing only mechanical connection between those parts for utmost
construction integrity. Accordingly, utilization of adhesives,
epoxies and welds in the construction of the golf head is
avoided.
Yet another object of the invention is to provide a head for a golf
club incorporating a unique, deflectable face plate for striking a
golf ball and a cooperating element for reinforcing that face
plate. The plate and reinforcing element are mounted to a body
shell so as to provide a gap therebetween. This gap initially
provides cushioning upon impact with the golf ball so as to improve
feel. The gap further functions in the manner of a spring, creating
a snap action at impact so as to provide better power and longer
hitting distances. The gap also serves to effectively decouple a
significant portion of the overall club head mass from direct
contact with the golf ball at the instant of impact with the face
plate This insures straighter, truer shot making.
Yet another object of the invention is to provide a head for a golf
club and a golf club incorporating a minimum number of component
parts that are specifically designed to maximize perimeter
weighting. In this way, a more "forgiving" golf club is provided
that produces straighter shots even when a golf ball is miss hit by
striking the ball on the club face near the toe or heel a
significant distance from the center-of-gravity.
Additional objects, advantages and other novel features of the
invention will be set forth in part in the description that follows
and in part will become apparent to those skilled in the art upon
examination of the following or may be learned with the practice of
the invention. The objects and advantages of the invention may be
realized and obtained by means of the instrumentalities and
combinations particularly pointed out in the appended claims.
To achieve the foregoing and other objects, and in accordance with
the purposes of the present invention as described herein, an
improved head is provided for a golf club. The golf club head
incorporates a body shell and a face plate held on the body shell
for striking a golf ball. The face plate is deflectable from a
static position to a striking position as a result of the stress
produced when striking the golf ball.
The golf club head further includes an element mounted on the body
shell for reinforcing the face plate. This is done by means of
engagement with the face plate when the face plate is in the
striking position. Further, means are provided for maintaining a
gap between the reinforcing element and the face plate when the
face plate is in the static position. This gap may be filled with
air, foam or other resilient material so as to provide a
spring-like cushioning effect immediately upon the striking of the
golf ball. This improves the feel of the club and adds to the
confidence of the golfer. Further, as will be described in greater
detail below, the resulting snap action provides an impression of
increased power and produces longer hitting distances.
Additionally, the gap effectively decouples a significant portion
of the weight of the club head from the golf ball at the very
instant of impact of the golf ball with the face plate. Thus, at
that moment less mass is in direct contact with the golf ball and,
accordingly, in the instance of an off-center hit less slice or
hook spin is produced. As a result, straighter, truer shot making
is achieved.
More specifically, the body shell of the golf club head is
preferably integrally cast utilizing an investment casting process.
Accordingly, the body shell includes an integral cast top, sole and
side wall. Only a single opening remains.
The reinforcing element is then introduced into the body shell
through this opening. Preferably, the reinforcing element
incorporates a support plate for engaging the face plate when the
face plate is in the striking position, an arched backing plate for
engaging the body shell and ribs for connecting the arched backing
plate and support plate together. A plurality of spaced ribs are
preferably utilized as they provide the necessary strength while
adding little mass. Advantageously, the resulting mass savings may
be redistributed around the perimeter of the body shell for
additional benefits while still maintaining an equivalent swing
weight. The reinforcing element may be held in position in the body
shell by means of polyurethane foam, a mechanical wedge and/or
other appropriate means known in the art for such a purpose.
The face plate is mounted on the body shell to close the opening. A
completely mechanical mounting is preferably utilized in place of
the relatively weak and less desirable adhesive, epoxy and welding
connections utilized in prior art head designs. More particularly,
the integral body shell of the club head is cast to include a z or
s-shaped channel and an associated bendable mounting flange both
about the perimeter of the body shell opening. The face plate also
includes a cooperating z or s-shaped lug about its entire
perimeter. The z-shaped lug is sized for insertion into and receipt
within the z-shaped channel of the body shell. The mounting flange
is then bent over to close the z-shaped channel and capture the
mounting lug thereby mechanically securing the face plate and body
shell together.
It should further be appreciated that the mountings of the
reinforcing element and face plate to the body shell cooperatively
function to maintain a gap between the reinforcing element and the
face plate when the face plate is in the static position.
Preferably, this gap is between 0.001 and 0.3 inches in thickness.
It may be filled with air or other resilient material to provide a
cushioning effect at the moment of impact with a golf ball.
Additionally, it is preferred that the face plate be constructed
from a material that is deflectable from the static position to the
striking position as a result of the stress produced while striking
a golf ball. Upon reaching the striking position the face plate
engages and is reinforced by the reinforcing element thereby
resisting further deflection and transferring full energy to the
golf ball. To achieve this end it is preferred that the face plate
be constructed from various metals, nonmetals and composite
materials having a thickness of between 0.01-0.30 inches. Further,
the face plate should have a tensile strength between 40.0-250.0
ksi and/or provide a minimum yield strength of between 40.0 ksi and
a modulus of elasticity of between 10.times.10.sup.3
-20.times.10.sup.3 ksi.
In accordance with yet another aspect of the present invention, a
golf club is provided incorporating a golf club head as just
described. Specifically, such a golf club includes a shaft
constructed of material with an appropriate flexibility including,
but not limited to titanium, graphite/boron and stainless steel.
The shaft includes a proximal end and a distal end. A handle or
grip of a type of construction known in the art is received over
the proximal end and the club head as described is received and
mounted to the distal end.
Still other objects of the present invention will become apparent
to those skilled in this art from the following description wherein
there is shown and described a preferred embodiment of this
invention, simply by way of illustration of one of the modes best
suited to carry out the invention. As it will be realized, the
invention is capable of other different embodiments and its several
details are capable of modification in various, obvious aspects all
without departing from the invention. Accordingly, the drawings and
descriptions will be regarded as illustrative in nature and not as
restrictive.
BRIEF DESCRIPTION OF THE DRAWING
The accompanying drawing incorporated in and forming a part of the
specification, illustrates several aspects of the present
invention, and together with the description search to explain the
principles of the invention. In the drawing:
FIG. 1 is an exploded view of a head for a golf club constructed in
accordance with the teachings of the present invention;
FIG. 2a is a cross-sectional view of the head shown in FIG. 1
showing the gap present between the reinforcing element and the
face plate when the face plate is in the static position;
FIG. 2b is a cross-sectional view along the same line as FIG. 2a
which showing the relative position of the reinforcing element and
the face plate when the face plate is deflected into the striking
position upon striking a golf ball;
FIG. 3 is a schematical front elevational view showing the
multi-piece tool die used to form the interior wall or hollow
section of the club head;
FIG. 4 is a detailed view showing the mounting of the face plate to
the body shell; and
FIG. 5 is a partially cut away, perspective view of a golf club
constructed in accordance with the teachings of the present
invention.
Reference will now be made in detail to the present preferred
embodiment of the invention, an example of which is illustrated in
the accompanying drawing.
DETAILED DESCRIPTION OF THE INVENTION
Reference is now made to FIGS. 1, 2a and 2b showing in detail the
head 10 of the present invention for a golf club. As shown, the
head 10 includes a body shell 12, a face plate 14 held on the body
shell for striking a golf ball and a reinforcing element 16 mounted
within the body shell behind the face plate.
The body shell 12 may be formed from any appropriate material but
preferably is cast from metal utilizing an investment casting
process so as to include an integral top wall 18, sole 20, side
wall 22 and hosel 23. Only an opening 24 remains. More
particularly, in a accordance with the investment casting process,
a master pattern of the club head is made and a master die is
produced from this pattern. In this instance, the master die
actually comprises an outer two-piece die (not shown) and a
cooperating inner, multi-piece tool die D (see FIG. 3) for forming
the interior, or hollow section of the body shell 12. Further, a
high temperature ceramic dowel W is positioned to form the inner
wall of the integral hosel 23. Molten wax is injected into the
cooperating dies to form a wax pattern P of the club head 10.
Once the wax hardens, the outer die is separated and the associated
inner multi-piece tool die D and dowel W are removed from the wax
pattern P. Specifically, it should be appreciated that the hollow
inner cavity of the body shell 12 of the wax pattern P is larger
than the striking face opening 24 through which the inner tool die
elements extend. Accordingly, the die members must be removed in a
particular order. With reference to FIG. 3, the central element
D.sub.1, including the lug L is removed first by withdrawing from
the remaining tool elements through the face plate opening 24 in
the wax pattern P. Next, the element D.sub.2 is laterally shifted
toward the center of the opening 24 and then withdrawn in the same
manner. Element D.sub.3 is then manipulated in the same manner.
This leaves the necessary clearance to laterally shift the elements
D.sub.4, D.sub.5, D.sub.6 and D.sub.7, one element at a time,
towards the center of the opening 24 where they too may be
withdrawn from the body shell 12 of the wax pattern P. The wax
pattern P is then dipped into a thin slurry of finely ground
refractory. This produces a thin but very smooth layer of
investment material adjacent to the wax pattern P on both the inner
and outer surfaces and insures a smooth surface and good detail in
the final product. If desired, repeated dipping can be utilized to
increase the thickness of the coating.
Next, the coated wax pattern P is positioned in a flask partially
filled with investment material. Additional investment material is
then poured into the flask around and into the wax pattern. The
container is vibrated to remove any entrapped air and settle the
investment material around the wax pattern P. The investment
material is then allowed to harden.
Subsequent to this, the wax pattern P is permitted to melt and run
out of the mold. The mold is then preheated in preparation for
pouring of the molten metal or other material from which the head
10 is to be formed. Various methods beyond simple pouring may be
utilized to insure complete filling of the mold. After hardening,
the casting is removed from the mold by breaking loose the
investment material.
The reinforcing element 16 may be formed from any appropriate
material having relatively high strength and relatively low mass.
Preferably, aluminum alloy or plastic such as nylon is utilized. As
best shown in FIG. 1, the reinforcing element 16 comprises a
support plate 30 for backing the face plate 14, an arched backing
member 32 for engaging the body shell 12 and a series of spaced
ribs 34 for connecting the arched backing member to the support
plate. The reinforcing element 16 may be integrally formed as a
unit or joined together from individual component parts.
The reinforcing element 16 is inserted into the body shell 12
through the face plate opening 24. More specifically, the opening
24 provides sufficient clearance to allow the reinforcing elements
16 to be inserted in position with the arched backing member 32
seating against the interior wall of the body shell 12. The
reinforcing element 16 is then secured in position by any means
known in the art appropriate for that purpose. For example, when
the reinforcing element 16 is seated and held in proper position in
the body shell 12, polyurethane foam 36 may be injected through an
orifice (not shown) in the support plate 30. As the foam 36 expands
it fills the space between the support plate 30 and the arched
backing member 32 around the ribs 34 so as to provide a tight
friction fit. Of course, other methods of anchoring may be utilized
including but not limited to fasteners extending through the wall
of the body shell 12 into engagement with the reinforcing element
16 and/or a mechanical wedge between the body shell and reinforcing
element to bind them together.
Once the reinforcing element 16 is secured in position in the body
shell 12, the face plate 14 is anchored in position across the
opening 24. Since adhesive, epoxy and welded joints are relatively
weak when compared to the surrounding material and therefore prone
to stress concentration and failure, a completely mechanical
mounting is utilized. More particularly, as best shown in detail in
FIG. 4, the body shell 12 includes an integrally cast z-shaped
channel 38 (with a shoulder angle A between 70.degree.-89.degree.)
and an associated bendable mounting flange 40. Both of these
structures are provided about the peripheral margin of the body
shell opening 24. The face plate 14 also includes a cooperating
z-shaped lug 42 about the entire perimeter of the face plate.
When mounting the face plate 14 to the body shell 12, the face
plate is heated, causing an expansion so that the z-shaped lug 42
is of sufficient dimension to be inserted into and received in the
z-shaped channel 38 of the body shell 12. As the face plate 14
subsequently cools, it contracts to provide a tight frictional fit.
For further security, the mounting flange 40 is then bent over to
close the z-shaped channel 38 and capture the mounting lug 42 in
position.
In accordance with an important aspect of the present invention, it
should be appreciated that the face plate 14 is constructed to
withstand the stress of impact with a golf ball while providing for
some limited deflection from the static position shown in FIG. 2a
to the striking position shown in FIG. 2b.
To achieve this end, the face plate 14 may be constructed from
materials selected from a group consisting of metals, non-metals
and composites. Such materials include but are not limited to
various stainless steels, titanium alloys, various composite
materials incorporating boron, various types of natural wood and
various graphite materials as well as those incorporating a woven
fiber mesh such as KEVLAR. In order to provide the necessary
strength to withstand the impact of the golf ball while also
providing the desired amount of deflection, the material utilized
preferably has a tensile strength of between 40.0-250.0 ksi and a
thickness of between 0.01-0.30 inches. The face plate also
preferably has a minimum yield strength of 40.0 ksi and a modulus
of elasticity of between 10.times.10.sup.3 20.times.10.sup.3
ksi.
As further shown with reference to FIG. 2a, the face plate 14 and
reinforcing element 16 are mounted to the body shell 12 so as to
maintain a gap G between the rear wall of the face plate and the
front wall of the support plate 30 when the face plate is in the
static position. Preferably, this gap G is between 0.001 and 0.30
inches in thickness. It may be filled with air as shown in FIG. 2a.
Alternatively, other resilient material may be provided in the gap
G to provide a spring-like cushioning effect at the instant of
impact with a golf ball.
More specifically, at the point of the swing when the face plate 14
strikes the golf ball, the face plate 14 is deflected rearwardly
through the gap G. This cushions the blow at the instance of impact
thereby improving the feel of the club and increasing the
confidence of the golfer. Further, the gap G also effectively
functions to decouple a portion of the mass of the golf club in
direct contact with the golf ball at the instant of impact. As a
result, less slice or hook spin is imparted to the golf ball when
the ball is struck off-center relative to the center-of-gravity of
the club head 10. As a result, the tendency to slice or hook is
reduced thereby allowing the golfer to play more shots to a desired
position in the fairway or the green.
As the face plate 14 fully deflects to the ball striking position
shown in FIG. 2b, it should be appreciated that the face plate
physically engages the support plate 30. Accordingly, the
deflection of the face plate is suddenly stopped and a full
transfer of energy is made for the first time from the club head to
the golf ball. This results in a snap action that provides better
power and longer hitting distances. Further, the stress from the
impact is communicated rearwardly from the support plate 30 along
the ribs 34 to the arched backing member 32. From there it is
semi-radially directed about the body shell 12. This semi-radial
and substantially equal distribution of stress functions with the
cushioning effect of the gap G to provide a significantly enhanced
feel for the user of a golf club incorporating the head 10 of the
present design. As a result of these real and perceived performance
enhancements, the golfer's level of play is significantly
enhanced.
As best shown in FIG. 5, the head 10 of the golf club includes a
hosel 23 that is adapted for connection to the distal end of an
elongated shaft 44. The shaft 44 is constructed of a material with
an appropriate flexibility including, but not limited to titanium,
graphite/boron and stainless steel. A grip 46 is mounted to the
distal end of the shaft 44. The grip is of a type of construction
known in the art and may be formed, for example, from leather or
rubber. The rubber may include fiber cord or other material to
improve the grip of the hands and prevent slipping.
In summary, numerous benefits result from employing the concepts of
the present invention. The club head 10 provides increased power
and accuracy for longer and straighter shot making. Further,
through the (1) synergistic effect of a purely mechanical
connection between the face plate 14 and body shell 12, (2)
cushioning during deflection of the face plate through the gap G at
impact and (3) the further transmission of impact stresses through
the support plate 30, ribs 34 and arched backing member 32, the
golfer is provided with the necessary feedback to control the
flight of the ball and feel confident in his or her shot
selection.
The foregoing description of a preferred embodiment of the
invention has been presented for purposes of illustration and
description. It is not intended to be exhaustive or to limit the
invention to the precise form disclosed. Obvious modifications or
variations are possible in light of the above teachings. For
example, while a golf club head of the "wood" type is described in
detail in this specification, the concepts are not limited to
specific application thereto and may, in fact, be equally applied
to a golf club of the iron type. The embodiment was chosen and
described to provide the best illustration of the principles of the
invention and its practical application to thereby enable one of
ordinary skill in the art to utilize the invention in various
embodiments and with various modifications as are suited to the
particular use contemplated. All such modifications and variations
are within the scope of the invention as determined by the appended
claims when interpreted in accordance with breadth to which they
are fairly, legally and equitably entitled.
* * * * *