U.S. patent application number 09/738177 was filed with the patent office on 2002-06-20 for golf club head.
Invention is credited to Carr, Rick, Heffernan, Paul, Oshinomi, Kirk.
Application Number | 20020077195 09/738177 |
Document ID | / |
Family ID | 24966891 |
Filed Date | 2002-06-20 |
United States Patent
Application |
20020077195 |
Kind Code |
A1 |
Carr, Rick ; et al. |
June 20, 2002 |
Golf club head
Abstract
The head of a golf club is improved by reducing the drag and
wake turbulence produced in the air when the golf club is swung to
strike a golf ball. The club head has a convex sole with an
elongated depression defined therein. The inboard end of the
depression is located proximate both the heel and the ball-impact
face and extends outwardly at a diverging angle from the
ball-impact face to an outboard extremity located inboard from the
toe of the club head. This depression or channel is thereby closely
aligned with the direction of travel of the club head during a
normal downswing and follow through of a golf stroke. Also, the top
of the club head is covered with a relatively rough coating, such
as a textured paint with granules encapsulated therein. The
roughness average of the top surface of the club head, as measured
by a profilometer, is it least three times as great as that of the
ball-impact face and at least three times as great as that of the
sole of the club head.
Inventors: |
Carr, Rick; (Huntington
Beach, CA) ; Oshinomi, Kirk; (Torrance, CA) ;
Heffernan, Paul; (La Costa, CA) |
Correspondence
Address: |
Charles H. Thomas
CISLO & THOMAS LLP
Suite 405
4201 Long Beach Blvd.
Long Beach
CA
90807-2022
US
|
Family ID: |
24966891 |
Appl. No.: |
09/738177 |
Filed: |
December 15, 2000 |
Current U.S.
Class: |
473/328 |
Current CPC
Class: |
A63B 53/0433 20200801;
A63B 53/0437 20200801; A63B 2225/01 20130101; A63B 60/006 20200801;
A63B 60/00 20151001; A63B 53/04 20130101; A63B 53/0408 20200801;
A63B 53/0466 20130101 |
Class at
Publication: |
473/328 |
International
Class: |
A63B 053/04 |
Claims
I claim:
1. In a golf club head having a ball-impact face, a sole, a top, a
back, a heel, a toe, and a hozzle, the improvement wherein a
depressed channel is defined in said sole and extends from an
inboard extremity thereof proximate both said heel and said
ball-impact face outwardly at a diverging angle from said
ball-impact face to an outboard extremity located inboard from said
toe.
2. A golf club head according to claim 1 further characterized in
that said ball-impact face is substantially flat and said channel
is aligned at an angle of between about thirty degrees and about
sixty degrees relative to said ball-impact face.
3. A golf club head according to claim 2 wherein said channel is
between about two centimeters and about three centimeters in width
and is aligned at an angle of about forty-five degrees relative to
said ball-impact face.
4. A golf club head according to claim 1 wherein said channel is
between about two millimeters and about four millimeters in maximum
depth, between about five centimeters and about seven centimeters
in length and between about two centimeters and about three
centimeters in maximum width.
5. In a golf club head having a ball-impact face, a sole having a
convex surface, a top, a back, a heel, a toe, and a hozzle, the
improvement wherein an elongated concave depression is defined in
said convex surface of said sole and said concave depression is
aligned to extend from a location at said heel and proximate said
ball-impact face away from said heel and at an acute angle of
between about thirty degrees and about sixty degrees relative to
said ball-impact face and said concave depression terminates
inboard from said toe.
6. A golf club head according to claim 5 wherein said depression is
between about two millimeters and about four millimeters in maximum
depth, between about five centimeters and about seven centimeters
in length and between about two centimeters and about three
centimeters in maximum width.
7. A golf club head according to claim 6 wherein said depression is
aligned at an angle of between about forty-five degrees and about
fifty-five degrees relative to said ball-impact face.
8. A golf club head according to claim 6 wherein said depression is
aligned at an angle of about fifty degrees relative to set
ball-impact face.
9. A golf club head according to claim 8 wherein said ball-impact
face has an arithmetic mean of profile roughness of between about
0.67 microns and about 0.81 microns, said sole has an arithmetic
mean of profile hardness of between about 0.82 microns and about
1.1 microns, and said top has an arithmetic mean of profile
roughness at least about three times as great as that of said
ball-impact face and at least about three times as great as that of
said sole.
10. A golf club head according to claim 9 wherein said top has an
arithmetic mean of profile roughness of between about 3.3 microns
and about 3.9 microns.
11. A golf club head according to claim 10 wherein said back also
has an arithmetic mean of profile roughness of between about 3.3
microns and about 3.9 microns.
12. In a golf club head having a ball-impact face, a sole, a top, a
back, a heel, a toe, and a hozzle, the improvement wherein said
ball-impact face has an arithmetic mean of profile roughness of
between about 0.67 microns and about 0.81 microns, said sole has an
arithmetic mean of profile roughness of between about 0.82 microns
and about 1.1 microns, and said top has an arithmetic mean of
profile roughness at least about three times as great as that of
said ball-impact face and it least about three times as great as
that of said sole.
13. A golf club head according to claim 12 wherein said top has an
arithmetic mean of profile roughness of between about 3.3 microns
and about 3.9 microns.
14. A golf club head according to claim 13 wherein said back also
has an arithmetic mean of profile roughness of between about 3.3
microns and about 3.9 microns.
15. A golf club head according to claim 12 wherein said sole is
formed with a convex surface that extends to said heel, said toe,
said back, and said ball-impact face, and an elongated, concave
depression is defined in said convex surface of said sole and said
concave depression is aligned to extend from a location at said
heel and proximate said ball-impact face away from said heel and at
an acute angle of between about thirty-five degrees and about
sixty-five degrees relative to said ball-impact face.
16. A golf club head according to claim 15 wherein said depression
is between about two millimeters and about four millimeters in
maximum depth, between about five centimeters and about seven
centimeters in length, and between about two centimeters and about
three centimeters in maximum width.
17. A golf club head according to claim to 16 wherein said
depression is aligned at an angle of about forty-five degrees
relative to said ball-impact face.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an improved construction
for a golf club head. The invention has particular applicability to
the types of golf clubs used to drive golf balls long distances,
such as a driver.
[0003] 2. Description of the Prior Art
[0004] A wide variety of golf club head configurations have been
devised over the years in efforts to aid golfers in enhancing their
proficiency in playing the game of golf. While golf club heads have
been manufactured in many different shapes, virtually all golf club
heads have the same basic parts. Specifically, a golf club head is
comprised of a ball impact face, a sole, a top, a heel, a toe, and
a back
[0005] Also, golf club heads designed for use on clubs for shots of
prescribed distances have certain similarities to each other. For
example, the heads of golf club drivers and mashies are relatively
massive. These club heads typically have a width of between about
five and ten centimeters as measured across the sole from the ball
impact face to the back and a length of about seven to eleven
centimeters as measured across the sole between the heel and the
toe of the club head. A golf club head for a driver typically
weighs between about one hundred forty grams and about three
hundred forty grams.
[0006] Within these basic measurement ranges there are a wide
variety of golf club head configurations. One golf club head
configuration which is designed to reduce drag for a wood type golf
club is described in U.S. Pat. No. 4,850,593. The golf club head
described in this patent has a trough or groove defined in its sole
which is aligned to extend generally parallel to the ball-impact
face across the entire length of the sole from the heel to the toe
of the club head. One defect in this design, however, is that with
the normal follow through of a driving stroke the trough is
oriented at a very significant angle relative to the path of travel
of the club head through the air. As a consequence, airflow past
the sole of the club head as the club head moves through the air is
more or less perpendicular to the direction of alignment of the
trough on the club head sole. This actually increases the
turbulence of the air in the wake of the club head passing through
the air. As a consequence, an inordinate amount of the power of the
stroke is expended in disturbing the air through which the club
passes.
[0007] Also, in the design of prior art golf club heads, it is
known that the club head surface and outer surface structure is an
integral part of the golf club head and overall golf club. The
accepted belief in golf club head design is that the outer surface
of the head should be as smooth as possible so as to minimize air
resistance as the head is swung through the air to drive a golf
ball a long distance. The concept has been that a smooth outer
surface of a golf club head will facilitate airflow past the head
surface. The goal in golf club head design is to produce a golf
club head which generates the least possible air resistance in its
movement, particularly movement at high velocity. To this end golf
club heads have typically been designed with as smooth an outer
surface as possible without measurable surface roughness or
texture.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide an
improved golf club head having both a superior shape or
configuration and also a novel and superior surface texture
coating. To this end the structure and surface treatment of a golf
club head are altered from prior designs to manipulate and reduce
surface airflow and turbulence over the surface of the club head
both during the downswing phase of the golf stroke at which the
club head reaches its maximum velocity, and also during the follow
through once the ball has been hit. This reduction in surface
airflow turbulence is achieved by the formation of a trough in the
club head sole having a unique alignment relative to the
ball-impact face and also by coating portions of the club head with
a granular or textured coating. Each of these features assists in
the breakup of airflow and reduces the drag vacuum so that the club
head travels faster and becomes more stable during both the
downswing and the follow through. The improved surface texture
coating and the creation of a trough in the sole of the club head
that is substantially aligned with the direction of club head
travel during the entire stroke improves the Reynolds numbers for
the club head. Reynolds numbers are used by aeronautical engineers
to show a measurement of air drag on an object.
[0009] Contrary to conventional wisdom, it has been discovered,
according to the present invention, that a smooth outer surface on
the golf club head produces greater air resistance and wake
turbulence than a golf club head covered with a textured or
granulated surface coating that exhibits a certain degree of
roughness. It has been discovered, according to the present
invention, that air turbulence is particularly reduced if the top
of the golf club head is coated with a granulated coating. Air
turbulence is further reduced if this granulated coating is applied
to the back of the club head as well.
[0010] The degree or extent of surface roughness of a golf club
head is measured with a profilometer using the "Ra" scale, which is
calibrated in microns. Roughness readings on the "Ra" scale
represent the arithmetical mean of all profile values. This measure
of roughness is also known as "roughness average". In determining
roughness average according to the present invention data was
collected using a Perthen profilometer.
[0011] In one broad aspect the present invention may be considered
to be an improvement in a golf club head having a ball-impact face,
a sole, a top, a back, a heel, a toe, and a hozzle. According to
the improvement of the invention a depressed channel is defined in
the sole and extends from an inboard extremity thereof proximate
both the heel and the ball-impact face outwardly at a divergent
angle from the ball-impact face to an outboard extremity located
inboard from the toe. This channel should be aligned at an angle of
between about thirty-five and about sixty-five degrees relative to
the ball-impact face. The angle of alignment is preferably about
fifty degrees. Also, the channel does not extend all the way to
across the sole, but terminates well short of the toe of the club
head.
[0012] In another broad aspect the invention may be considered to
be an improvement in a golf club head having a ball-impact face, a
sole having a convex surface, a top, a back, a heel, a toe, and a
hozzle. According to the improvement of the invention, an
elongated, concave depression is defined in the convex surface of
the sole. The concave depression is aligned to extend from a
location at the heel end proximate the ball-impact face away from
the heel and at an acute angle of between about thirty-five and
sixty-five degrees relative to the ball-impact face and terminates
inboard from the toe of the club head. The concave depression or
channel is preferably between about two and about three centimeters
in width, between about five and about seven centimeters in length,
and is between about two and about four millimeters in maximum
depth.
[0013] In still another broad aspect, the invention may be
considered to be an improvement in a golf club head having a
ball-impact face, a sole, a top, a back, a heel, a toe, and a
hozzle. According to the improvement of the invention the
ball-impact face has an arithmetic mean of profile roughness of
between about 0.67 and about 0.81 microns, the sole has an
arithmetic mean of profile roughness of between about 0.82 and
about 1.1 microns, and the top has an arithmetic mean of profile
roughness at least about three times as great as that of the
ball-impact face and it least about three times as great as that of
the sole. The top preferably has an arithmetic mean of profile
roughness of between about 3.3 microns and about 3.9 microns.
Preferably also the back has an arithmetic mean of profile
roughness of between about 3.3 microns and about 3.9 microns.
[0014] The invention may be described with greater clarity and
particularity by reference to the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view illustrating a preferred
embodiment of a golf club head according to the invention mounted
on the shaft of a golf driver.
[0016] FIG. 2 is a front elevational view of the golf club head of
FIG. 1 shown in isolation.
[0017] FIG. 3 is a rear elevational view of the golf club head of
FIG. 2.
[0018] FIG. 4 is a top plan view of the golf club head of FIG.
2.
[0019] FIG. 5 is a bottom plan view of the golf club head of FIG.
2.
[0020] FIG. 6 is an end view as seen from the toe of the club head
of FIG. 2.
[0021] FIG. 7 is an end view as seen from the heel of the club head
of FIG. 2.
DESCRIPTION OF THE EMBODIMENT
[0022] FIG. 1 illustrates a PD 901 titanium golf club head 10
mounted upon the lower extremity of a golf club shaft 12 of a golf
driver. The golf club head 10 has a substantially planar
ball-impact face 14, a convex top surface 16, a convex sole 18
illustrated in FIG. 5, a back 20 located opposite the ball-impact
face 14, a heel 22, and a toe 24. The golf club head 10 also has a
hozzle 26 located at the top of the heel 22 at the junction between
the heel 22 and the top surface 16. As in conventional golf clubs,
the hozzle 26 defines a tubular opening therewithin to receive the
cylindrical attachment tip of the golf club shaft 12.
[0023] The golf club head 10 is preferably formed of aluminum and
titanium and is fabricated as a two-part hollow casting. The
general overall size and shape of the golf club head 10 is fairly
conventional. The sole is about 7.5 centimeters in width as
measured between the ball-impact face 14 and the back 20 at the
transition between the sole 18 and the back 20. The top surface 16
is about 11.5 centimeters in length as measured from the base of
the hozzle 26 to the transition between the top surface 16 and the
toe 24. The club head 10 weighs about two hundred fifty grams when
detached from the golf club shaft 12. The sole 18 has a convex
surface that extends from the heel 22 in a gradual, smooth
transition therewith to the toe 24 and the back 20. The transition
of the convex surface of the sole 18 with the back 20 and toe 24 is
also quite gradual. Like the sole 18, the top surface 16 also has a
slightly convex surface configuration.
[0024] The shape of the club head 10 does differ in several
important respects from the shape of conventional golf club heads,
however. The sole 18 of the golf club head 10 has a concave trough,
depression, or channel 28 formed in its otherwise convex,
downwardly facing surface. The depression 28 has an inboard end 30
that extends from a location at the bottom of the heel 22 and
proximate the ball-impact face 14, away from the heel 22 and at an
acute angle relative to the ball-impact face 14. The longitudinal
alignment of the depression 28 may be considered to be determined
by the straight line 32 in the plan view projection of FIG. 5 that
extends from the inboard end 30 of the trough 28 through the
outboard end 34 thereof. The line 32 longitudinally bisects the
plan view projection of the channel or depression 28 with one-half
of the area of the plan view projection of the depression 28 lying
on each side of the line 32 as illustrated in FIG. 5. This plane is
perpendicular to the ball-impact face 14.
[0025] While there is a very slight convex curvature to the
ball-impact face 14, for purposes of defining the orientation of
the alignment of the channel 28, the ball-impact face 14 may be
considered to be defined by the plane 36 shown in FIGS. 4, 5, 6,
and 7. One-half of the surface area of the ball-impact face 14 lies
on each side of the plane 36. However, no portion of that surface
area is more than about three millimeters from the plane 36.
[0026] The channel 28 is aligned at an acute angle relative to the
ball-impact face 14, as defined by the intersection of the line 32
of alignment of the depression 28 with the ball-impact face plane
36. The range of this angle of intersection can be between about
thirty-five degrees and about sixty-five degrees. The preferred
alignment of the channel or depression 28 relative to the
ball-impact face plane 36 is preferably about fifty degrees.
[0027] The concave depression 28 extends to a depth of between
about two and four millimeters at its maximum. The greatest depth
of the depression 28 is at the midpoint of the segment of the line
32 line that extends between the extremities of the inboard end 30
and the outboard end 34 within the depression 28. The depression 28
is between about five centimeters and seven centimeters in length
and between about two centimeters and about three centimeters in
maximum width. The preferred length of the depression 28 is about
six centimeters and the preferred maximum width is about two and
one-half centimeters.
[0028] It should be noted that the depression 28 does not extend
entirely across the sole 18. To the contrary, it terminates well
short of the toe 24 of the club head 10, as best shown in FIG. 3.
In the embodiment shown, the outboard end 34 of the depression 28
terminates at a distance of about three centimeters from the bottom
of the toe 24, as measured along the line 32. The demarcation
between the sole 18 and the toe 24 may be considered to be the line
of transition between the upper and outboard roughened area 39,
indicated by stippling and described hereafter, and the lower and
inboard smooth area 41 of the golf club head 10.
[0029] The golf club head 10 differs from conventional golf club
heads in other aspects as well. Specifically, both the top surface
16 and the back surface 20, as well as the toe 24 are covered with
a granulated, textured paint which creates a certain roughness on
these surfaces. This area of roughness is indicated at 39 by
stippling in the drawing figures. The ball-impact face 14 is quite
smooth and has an arithmetic mean of profile roughness as measured
by a profilometer of between about 0.67 microns and about 0.81
microns. The surface of the sole 18 is also quite smooth and has an
arithmetic mean of profile roughness of between about 0.82 microns
and about 1.1 microns.
[0030] In contrast, the top surface 16 has an arithmetic mean of
profile hardness at least about three times as great as that of the
ball-impact face 14 and at least about three times as great as that
of the sole 18. More specifically, the top has an arithmetic mean
of profile roughness of between about 3.3 microns and about 3.9
microns. This roughness preferably increases from a maximum near
the hozzle 26 to a minimum at the transition with the toe 24. At
the location 38 on the top surface 16 near the hozzle 26 the
arithmetic mean of profile roughness or roughness average is about
3.87 microns. This roughness decreases to about 3.55 microns at the
location 40 near the center of the top surface 16, and decreases
further to a roughness average of about 3.33 microns at the
transition 42 to the toe 24. The toe 24 also has a roughness
average of about 3.33 microns, and is indicated by stippling in the
drawing figures.
[0031] The roughness average of the ball-impact face 14 also varies
with distance from the hozzle 26. At the top of the ball-impact
face 14, indicated at 44, the roughness average is 0.67 microns.
The roughness increases slightly to about 0.81 microns at the
center 46 of the ball-impact face surface 14, but decreases to
about 0.78 microns at its transition 48 to the sole 18.
[0032] The roughness average also varies across the surface of the
sole 18. Specifically, in the area 50 between the inboard end 30 of
the depression 28 and the ball-impact face 14, the roughness
average is about 1.1 microns. Within the depression 28 the
roughness average is about 0.82 microns. At the outboard portion 52
of the sole 18 the roughness average is about 0.84 microns.
[0033] When the golf club driver is swung to hit a golf ball, the
golf club head 10 moves more smoothly through the air and creates
less wake turbulence and vacuum than a conventional golf club head.
As a consequence, the club head 10 will move with a greater speed
and under more accurate control as contrasted with the movement of
the head of a conventional golf club swung in the same stroke. The
presence and the configuration and orientation of the channel or
depression 28 and also the modification of the surface roughness of
several portions of the golf club head 10 thereby improve the power
and accuracy of a golfer's driving game.
[0034] Undoubtedly, numerous variations and modifications of the
invention will become readily apparent to those familiar with golf
club head design. For example, the precise dimensions and
orientation of the elongated, shallow depression 28 in the
otherwise convex surface of the sole 18 will vary with different
sizes and shapes of golf club heads. Also, the exact roughness
average across the various surfaces of the golf club head will
likewise vary depending upon the size and shape of the club head.
Accordingly, the scope of the invention should not be construed as
limited to the specific embodiment depicted and described, but
rather as defined in the claims appended hereto.
* * * * *