Information
-
Patent Grant
-
6428427
-
Patent Number
6,428,427
-
Date Filed
Tuesday, October 3, 200023 years ago
-
Date Issued
Tuesday, August 6, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Sewell; Paul T.
- Varma; Sneh
Agents
-
CPC
-
US Classifications
Field of Search
US
- 473 324
- 473 332
- 473 340
- 473 349
- 473 341
- 473 291
- 473 330
- 473 350
- 473 342
- 473 345
- 473 346
- 473 329
- 228 176
-
International Classifications
-
Abstract
A golf club head (20) having a thin striking plate (30) with a smooth exterior surface and a thin layer (35) disposed on the exterior surface (53). The thin layer (35) has a plurality of scorelines (75) that absorb the shock during impact with a golf ball. The striking plate (30) has a thickness in the range of 0.010 inch to 0.200 inch, and the thin layer (35) has a thickness in the range of 0.003 inch to 0.050 inch. The striking plate (30) may have a uniform thickness or a variable thickness.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a golf club having a relatively thin striking plate. More specifically, the present invention relates to a golf club having a thin striking plate with a coating on the exterior surface of the striking plate.
2. Description of the Related Art
Present golf clubs have repositioned weight in order to lower the center of gravity for better performance. This repositioning of weight has for the most part attempted to thin the crown and striking plate of the golf club while precisely placing the weight in the sole of the golf club. However, thinning the striking plate too much may lead to failure of the golf club.
When the striking plate impacts a golf ball during a swing, large impact forces (in excess of 2000 pounds) are produced thereby loading the striking plate. In the relatively thin striking plates of hollow metal woods and cavity-back irons, these forces tend to produce large internal stresses in the striking plate. These internal stresses often cause catastrophic material cracking which leads to failure of the club head.
Computational and experimental studies on hollow metal woods and cavity-backed irons have demonstrated that such catastrophic material cracking most often occurs at impact points on the striking plate. These impact points require added strength to prevent club head failure.
In designing golf club heads, the striking plate must be structurally adequate to withstand large repeated forces such as those associated with impacting a golf ball at high speeds. Such structural adequacy may be achieved by increasing the striking plate stiffness so that the stress levels are below the critical stress levels of the material used in the striking plate. Typically, for metal woods, the striking plates are stiffened by uniformly increasing the thickness of the striking plate and/or by adding one or more ribs to the interior surface of the striking plate.
Uniformly increasing the thickness of the striking plate portion typically requires the addition of large amounts of material to adequately reduce the stress sufficient to prevent impact and/or fatigue cracking. However, the addition of such a large amount of material to a striking plate generally adversely affects the performance of the golf club.
One of the first patents to disclose variable face thickness was U.S. Pat. No. 5,318,300 to Schmidt et al., for a Metal Wood Golf Club With Variable Faceplate Thickness which was filed on Nov. 2, 1992. Schmidt et al discloses thickening the faceplate to prevent cracking.
A further disclosure of variable face thickness is disclosed in U.S. Pat. No. 5,830,084 to Kosmatka for a Contoured Golf Club Face which was filed on Oct. 23, 1996. Kosmatka addresses contouring the face to thicken certain regions while thinning other regions depending on the stress load experienced by such regions. Kosmatka also discloses a method for designing a face plate according to measured stress levels experienced during impact with a golf ball. Kosmatka, U.S. Pat. No. 5,971,868 for a Contoured Back Surface Of Golf Club Face, filed on Nov. 18, 1997, discloses similar contouring for an iron.
A more recent disclosure is Noble et al., U.S. Pat. No. 5,954,596, for a Golf Club Head With Reinforced Front Wall, which was filed on Dec. 4, 1997. Noble et al. discloses a face plate with the thickness portion at the geometric center, and gradually decreasing toward the top and bottom, and the sole and heel. The top and bottom ends along a line through geometric center have the same thickness, and the heel and sole ends along a line through geometric center have the same thickness.
Other references make partial disclosure of varying face thickness. One example is FIG. 8 of U.S. Pat. No. 5,505,453 which illustrates an interior surface of a face with a bulging center and decreasing thickness towards the heel and sole ends, similar to Noble et al. Another example is FIGS. 4C and 4D of U.S. Pat. No. 5,346,216 which discloses a bulging center that decreases in thickness toward the heel and sole ends, and the top and bottom end of the face, similar to Noble et al. However, the prior art has failed to design a striking plate or face plate that is thin and reduces scoreline concentration of the initial shock load during impact with a golf ball.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed at a golf club head having a thin striking plate that has a smooth exterior surface with a thin layer disposed on the exterior surface. The thin layer has a plurality of scorelines to absorb the initial shock load during impact with a golf ball and to distribute and reduce stress loads in the body of the golf club head.
One aspect of the present invention is a golf club head including a body, a striking plate and a thin layer. The body has a crown, a sole, a heel end, a toe end and a hollow interior. The striking plate is attached to the body. The striking plate has an interior surface facing toward the hollow interior and a smooth exterior surface opposite the interior surface. The striking plate has a thickness range of 0.010 inch to 0.200 inch. The thin layer is disposed on the exterior surface of the striking plate. The thin layer has a thickness of 0.005 inch to 0.100 inch, and can have a plurality of scorelines.
Another aspect of the present invention is a golf club head including a body, a striking plate and a thin layer. The body has a crown, a sole, a heel end, a toe end and a hollow interior. The striking plate is attached to the body and has a non-uniform or contour interior surface. The striking plate has an interior surface toward the hollow interior and a smooth exterior surface opposite the interior surface. The striking plate also has a central region, a transition region, a first peripheral region and a second peripheral region. The central region has a first thickness ranging from 0.125 inch to 0.145 inch and occupying 5% to 15% of the exterior surface of a core face area. The transition region encompasses the central region and occupies 35% to 50% of the exterior surface of a core face area. The first peripheral region encompasses the transition region and occupies 40% to 55% of the exterior surface of the core face. The first peripheral region has a second thickness less than the first thickness and ranges from 0.075 inch to 0.110 inch. The transition region has a thickness that transitions from the first thickness to the second thickness. The second peripheral region encompasses the first peripheral region and has a third thickness that ranges from 0.045 inch to 0.080 inch. The thin layer is disposed on the exterior surface of the striking plate. The thin layer has a thickness of 0.005 inch to 0.100 inch, and has a plurality of scorelines.
Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1
is a front plan view of a golf club head with the striking plate of the present invention.
FIG. 2
is a front plan view of the striking plate of
FIG. 1
showing the variable face thickness.
FIG. 2A
is a front plan view of the golf club head of
FIG. 1
with the variable face thickness pattern superimposed thereon.
FIG. 3
is a toe side view of the golf club head of FIG.
1
.
FIG. 3A
is a toe side exploded view of the golf club head of the present invention.
FIG. 3B
is a toe side exploded view of an alternative embodiment of the golf club head of the present invention.
FIG. 4
is a bottom plan view of the golf club head of FIG.
1
.
FIG. 5
is a top plan view of the golf club head of FIG.
1
.
FIG. 6
is a heel side view of the golf club head of FIG.
1
.
FIG. 7
is a front plan view of a fairway wood golf club head of the present invention with the variable thickness superimposed thereon.
FIG. 8
is a cross-sectional view along lines
8
—
8
of FIG.
5
.
FIG. 9
is a cross-sectional view along lines
9
—
9
of FIG.
2
A.
FIG. 10
is a cross-sectional view along lines
10
—
10
of FIG.
2
A.
FIG. 11
is a cross-sectional view along lines
11
—
11
of FIG.
2
A.
FIG. 12
is a cross-sectional view along lines
12
—
12
of FIG.
2
A.
FIG. 13
is a cross-sectional view along lines
13
—
13
of FIG.
2
A.
FIG. 14
is a cross-sectional view along lines
14
—
14
of FIG.
2
A.
FIG. 15
is a cross-sectional view along lines
15
—
15
of FIG.
2
A.
FIG. 16
is a cross-sectional view along lines
16
—
16
of FIG.
2
A.
FIG. 17
is an illustration of impact probabilities for high handicap golfers.
FIG. 18
is an illustration of impact probabilities for low handicap golfers.
FIG. 19
is a side view of a golf ball impacting the golf club-head of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As shown in
FIGS. 1-8
, a golf club head is generally designated
20
. The golf club head
20
has a body
22
with a crown
24
, a sole
26
, a ribbon
28
, a striking plate
30
, and a thin layer
35
disposed on the striking plate
30
. The striking plate
30
generally extends from a heel end
32
to a toe end
34
of the front of the golf club head
20
. The body
22
preferably has an internal hosel
36
for receiving the tip end of a shaft, not shown, through an aperture
38
. The golf club head has a body
22
that is preferably composed of a metal material such as titanium, titanium alloy, stainless steel, or the like, and is most preferably composed of a forged titanium material. The body
22
preferably has a large volume, ranging from 250 cubic centimeters to 400 cubic centimeters, most preferably 290 cubic centimeters to 350 cubic centimeters. The body
22
preferably weighs no more than 215 grams, and most preferably weighs between 180 and 205 grams. The body
22
has a hollow interior
23
.
The striking plate
30
may have a uniform thickness or a variable thickness. The exterior surface
53
of the striking plate is smooth while the interior surface
55
of the striking plate may be uniform or vary in thickness. The exterior surface also has an absence of scorelines since scorelines are stress concentrators during impact with a golf ball. Due to the extremely thin striking plate
30
, scorelines would lead to failure of the striking plate
30
. The thickness of the striking plate
30
ranges from 0.010 inch to 0.300, preferably from the 0.040 inch to 0.250, and most preferably from 0.060 inch to 0.150 inch. The thickness of the striking plate
30
is greatly determined by the size of the golf club head
20
, and the material composition of the striking plate
30
. Titanium alloys have a lower density than stainless steel, and thus a titanium alloy striking plate
30
allows for the weight to be distributed elsewhere in the body
22
.
The thin layer
35
is attached to the exterior surface
53
of the striking plate
30
. The thin layer
35
has a plurality of scorelines
75
thereon. The thin layer
35
absorbs the initial shock load, distributes the stress loads throughout the entire golf club head
20
, and reduces the stress load throughout the entire golf club head
20
. The thin layer
35
may cover the entire exterior surface
53
, or only a portion of the exterior surface
53
. The thin layer
35
has a thickness that ranges from 0.003 inch to 0.050 inch, more preferably from 0.005 inch to 0.025 inch, and most preferably 0.010 inch. The overall thickness of the striking plate
30
and the thin layer
35
preferably ranges from 0.020 inch to 0.250 inch, more preferably from 0.050 inch to 0.150 inch, and most preferably is 0.100 inch.
The thin layer
35
is preferably composed of a material that has a lower density than the material of the striking plate
30
. The thin layer
35
is preferably composed of a polymer material, a composite material, a lightweight metal material, or the like. Polymer materials that are used for the thin layer
35
include polyurethanes, polyamides, polyimides, polycarbonates, and the like. Lightweight metal that are used for the thin layer
35
materials include titanium, aluminum, beryllium, magnesium, zirconium alloys, and the like.
Preferably, the striking plate
30
is partitioned into a plurality of regions
40
,
42
,
44
and
46
, defmed by lines
41
,
43
,
45
and
47
, each having a different thickness or different thickness range. The striking plate
30
is unitary in construction, and may or may not be composed of the same material of the body
22
. The term unitary when used in conjunction with the striking plate
30
means that the striking plate
30
is a single piece and does not have additions to the interior surface
55
such as ribs or weighting members. The thin layer
35
is a separate component from the striking plate
30
. A central region
40
, defined by dashed line
41
, has a base thickness that is preferably the greatest thickness of the regions
40
,
42
,
44
and
46
. The base thickness ranges from 0.200 inch to 0.060 inch, preferably from 0.150 inch to 0.075 inch, and is most preferably within the range of 0.145 inch to 0.090 inch. A transition region
42
has a thickness that ranges between the thickness of the central region
40
and a first peripheral region
44
, preferably ranges from 0.150 inch to 0.090 inch, and most preferably ranges from 0.140 inch to 0.080 inch. The first peripheral region
44
has a thickness that ranges from 0.110 inch to 0.040 inch, preferably ranges from 0.105 inch to 0.050 inch, and most preferably ranges from 0.100 inch to 0.075 inch. A second peripheral region
46
preferably is the thinnest region of the striking plate regions
40
,
42
,
44
and
46
. The second peripheral region
46
has a thickness that ranges from 0.085 inch to 0.010 inch, preferably ranges from 0.080 inch to 0.045 inch, and most preferably ranges from 0.075 inch to 0.050 inch.
In a preferred embodiment, as shown in
FIG. 2
, the central region has a thickness range of 0.145 inch to 0.090 inch, the transition region
42
has a thickness range of 0.140 inch to 0.080: inch, the first peripheral region
44
has a thickness range of 0.105 inch to 0.090 inch, and the second peripheral region
46
has a thickness range of 0.075 inch to 0.050 inch.
Preferably, as shown in
FIG. 2
, the central region
40
is 5% to 15% of the surface area of the core face
49
of the striking plate
30
. The core face
49
is defined as the central region
40
, the region
42
and the first peripheral region
44
. The core face area of the striking plate
30
has an area between 4.80 square inches and 5.50 square inches, preferably between 5.10 square inches and 5.40 square inches, and most preferably 5.38 square inches. The transition region
42
is preferably 35% to 50% of the surface area of the core face
49
, and the first peripheral region
44
is preferably 40% to 55% of the surface area of the core face
49
. In a preferred embodiment, the central region is 8.8% of the surface area of the core face
49
, the transition region is 42.2% of the surface area of the core face
49
, and the first peripheral region
44
is 50% of the surface area of the core face
49
.
FIG. 7
illustrates an alternative embodiment of the present invention for a fairway wood golf club head
20
. In this embodiment, the central region has a thickness range of 0.135 inch to 0.125 inch, the transition region
42
has a thickness range of 0.130 inch to 0.090 inch, the first peripheral region
44
has a thickness range of 0.095 inch to 0.085 inch, and the second peripheral region
46
has a thickness range of 0.075 inch to 0.045 inch.
Table One sets forth the thickness ranges of the central region
40
, the first peripheral region
44
and the second peripheral region
46
for preferred embodiments for drivers (lofts 7 degrees through 12 degrees) and fairway woods (2 wood through 9 wood).
TABLE One
|
|
Striking Plate Thickness
|
Second Peripheral
First Peripheral
|
Club
Region
Region
Center Region
|
|
07° Driver
.050 ± .005
.100 ± .005
.140 ± .005
|
08° Driver
.050 ± .005
.100 ± .005
.140 ± .005
|
09° Driver
.050 ± .005
.100 ± .005
.140 ± .005
|
10° Driver
.050 ± .005
.100 ± .005
.140 ± .005
|
11° Driver
.050 ± .005
.100 ± .005
.140 ± .005
|
12° Driver
.050 ± .005
.100 ± .005
.140 ± .005
|
2 Wood
.050 ± .005
.090 ± .005
.130 ± .005
|
3 Wood
.055 ± .005
.090 ± .005
.130 ± .005
|
Strong 3
.060 ± .005
.090 ± .005
.130 ± .005
|
4 Wood
.060 ± .005
.085 ± .005
.125 ± .005
|
Strong 4
.065 ± .005
.090 ± .005
.130 ± .005
|
5 Wood
.065 ± .005
.085 ± .005
.125 ± .005
|
7 Wood
.070 ± .005
.085 ± .005
.125 ± .005
|
9 Wood
.075 ± .005
.085 ± .005
.125 ± .005
|
|
Cross-sections of the striking plate
30
, taken from
FIG. 2A
, are illustrated in
FIGS. 9-16
. The striking plate
30
has variable thickness, with the thickest portion in the center. The thin layer
35
has a uniform overall thickness.
FIG. 9
illustrates a vertical cross-section of the mid-section of the striking plate
30
with the central region
40
, the transition region
42
, the first peripheral region
44
and the second peripheral region
46
on the contoured interior surface
55
.
FIGS. 10 and 11
illustrate vertical cross-sections that are adjacent both sides of the mid-section, and which only includes the transition region
42
, the first peripheral region
44
and the second peripheral region
46
.
FIG. 12
illustrates a vertical cross-section on the heel end
32
of the striking plate
30
that has a wall of the internal hosel
36
integrated therewith in a preferred embodiment.
FIG. 12
otherwise shows the first peripheral region
44
and the second peripheral region
46
. Although the wall of the internal hosel
36
is shown as integrated with the striking plate
30
, alternative embodiments have the internal hosel off-set from the interior surface
55
of the striking plate
30
.
FIG. 13
illustrates a vertical cross-section of the toe end
34
of the striking plate
30
, which only includes the first peripheral region
44
and the second peripheral region
46
.
FIG. 14
illustrates a horizontal cross-section of the horizontal mid-section of the striking plate
30
, which shows the central region
40
, the transition region
42
, the first peripheral region
44
, the second peripheral region
46
, and the wall of the internal hosel
36
.
FIG. 15
illustrates a horizontal cross-section below the horizontal mid-section of the string plate
30
, which only includes the transition region
42
, the first peripheral region
44
, the second peripheral region
46
, and the wall of the internal hosel
36
.
FIG. 16
illustrates a horizontal cross-section further below the horizontal mid-section of the striking plate
30
, which only includes the first peripheral region
44
, the second peripheral region
46
, and the wall of the internal hosel
36
.
The striking plate
30
does not have scorelines. The plurality of scorelines
75
are disposed on the thin layer
35
. The scorelines
75
may be traditional indentations having a depth of from 0.001 inch to 0.025 inch, more preferably from 0.003 inch to 0.010 inch, and most preferably 0.005 inch. The contour of each of the scorelines
75
may be as described in co-pending U.S. patent application No. 09/431,518, filed on Nov. 1, 1999, entitled Contoured Scorelines For The Face Of A Golf Club, and incorporated by reference in its entirety. Alternatively, the scorelines may be projections
75
a
such as illustrated in FIG.
3
B. Such scoreline projections
75
a
preferably extend 0.003 inch to 0.010 inch from the surface
39
of the thin layer
35
.
As mentioned previously, the thickness of the regions
40
,
42
,
44
and
46
, and for the most part, the thickness of the striking plate
30
, corresponds to impact probability.
FIGS. 17 and 18
illustrate the impact points during a golf swing for high handicap players and low handicap players, respectively. As shown in
FIG. 17
, the high handicap players had impacts
90
within an elliptical area
100
that extended through the center of the striking plate
30
. In comparison, low handicap players had impacts
90
that were more concentrated and within a circular area
102
of the striking plate
30
. These impacts
90
illustrate the points on a striking plate
30
that have the highest probability of undergoing the greatest stress during impact with a golf ball. Therefore, these points require greater thickness than other areas of the string plate
30
. Thus, the regions
40
,
42
,
44
and
46
correlate to this impact probability in order to design a striking plate with greater thickness where it is needed instead of in areas low impact probability. The present invention may be described as being thinner at the heel and toe ends
32
and
34
than the central region
40
.
The variation in the thickness of the striking plate
30
also allows for the greatest thickness of regions
40
,
42
,
44
and
46
to be distributed in the center region
40
of the striking plate
30
thereby enhancing the flexibility of the striking plate
30
which corresponds to greater compliance of the striking plate
30
during impact with a golf ball thereby providing for reduced energy loss with allows for greater distance.
The striking plate
30
is preferably composed of a stainless steel. Alternatively, the striking plate
30
is composed of a titanium or titanium-alloy material. In yet an alternative embodiment, the striking plate
30
is composed of a vitreous metal such as iron-boron, nickel-copper, nickel-zirconium, nickel-phosphorous, and the like. Yet in further alternative embodiments, the striking plate
30
is composed of ceramics, composites or other metals.
The thin layer
35
is preferably attached to the exterior surface
55
of the striking plate
30
by an adhesive
37
, such as illustrated in FIG.
3
A. Other means of attachment include vapor deposition, pressure locking, attachment by screws, and the like.
From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims.
Claims
- 1. A wood-type golf club head comprising:a body composed of a metal material, the body having a crown, a sole, a heel end, a toe end and a hollow interior; a striking plate composed of a metal material attached to the body, the striking plate having an interior surface toward the hollow interior and a smooth exterior surface opposite the interior surface, the striking plate also having a central region, a transition region, a first peripheral region and a second peripheral region, the central region having a first thickness ranging from 0.125 inch to 0.145 inch and occupying 5% to 15% of the exterior surface of a core face area, the transition region encompassing the central region and occupying 35% to 50% of the exterior surface of a core face area, the first peripheral region encompassing the transition region and occupying 40% to 55% of the exterior surface of the core face, the first peripheral region having a second thickness less than the first thickness and ranging from 0.075 inch to 0.110 inch, the transition region having a thickness that transitions from the first thickness to the second thickness, the second peripheral region encompassing the first peripheral region and having a third thickness that ranges from 0.045 inch to 0.080 inch; and a polymer layer disposed on the exterior surface of the striking plate, the polymer layer having a thickness of 0.005 inch to 0.100 inch, the thin layer having a plurality of scorelines thereon.
- 2. A wood-type golf club head comprising:a body having a crown, a sole, a heel end, a toe end and a hollow interior, the body composed of a titanium material and having a volume in excess of 280 cubic centimeters and weighing less than 215 grams; a striking plate attached to the body, the striking plate having an interior surface toward the hollow interior and a smooth exterior surface opposite the interior she, the striking plate having a thickness range of 0.060 inch to 0.150 inch, the string plate composed of a titanium material and having an area greater 4.80 square inches; and a polymer layer disposed on the exterior surface of the sing plate, the polymer layer having a thickness of 0.005 inch to 0.050 inch, the thin layer having a plurality of scorelines thereon, each of the plurality of scorelines having a depth in the range of 0.003 inch to 0.025 inch, the polymer layer attached to the exterior surface by an adhesive.
- 3. The golf club head according to claim 2 wherein the golf club head has a COR of at least 0.83 under USGA test conditions.
- 4. The golf club head according to claim 2 wherein the plurality of scorelines is comprised of 13 horizontal scorelines.
- 5. The golf club head according to claim 2 wherein the thin layer has a central impact region that has a low friction and low energy loss, and a peripheral impact region that has a high friction coefficient and a high energy loss.
- 6. The golf club head according to claim 5 wherein the central impact region of the thin layer is composed of a first polymer material and the peripheral impact region of the thin layer is composed of a second polymer material.
- 7. The golf club head according to claim 6 wherein the first polymer material is a polyurethane material having a Shore D hardness greater than 50 and the second polymer material is a polyurethane material having a Shore D hardness lower than 40.
- 8. A wood-type golf club head comprising:a body composed of a titanium alloy material, the body having a crown, a sole and a striking plate which define a hollow interior, the sting plate having an interior surface toward the hollow interior and a smooth exterior surface opposite the interior surface, the sing plate hang a thickness range of 0.060 inch to 0.150 inch and an area greater than 4.80 square inches, wherein the body has a volume in excess of 280 cubic centimeters and a mass less than 215 grams; a single layer composed of a thermoset polyurethane adhesively attached to the smooth exterior surface of the striking plate, the single layer having a thickness ranging from 0.005 inch to 0.025 inch, the single layer having a plurality of scorelines, having a depth of 0.005 inch to 0.010 inch.
US Referenced Citations (16)