U.S. patent application number 09/804195 was filed with the patent office on 2001-07-26 for golf club head.
Invention is credited to Hasebe, Yuu, Imamoto, Yasunori, Kubota, Makoto, Mikame, Daisuke, Shimasaki, Hirato.
Application Number | 20010009873 09/804195 |
Document ID | / |
Family ID | 26372798 |
Filed Date | 2001-07-26 |
United States Patent
Application |
20010009873 |
Kind Code |
A1 |
Hasebe, Yuu ; et
al. |
July 26, 2001 |
Golf club head
Abstract
A golf club head having a hollow construction, including a
bar-like gravity adjusting piece (4) which extends longitudinally
from a toe (7) towards a heel (8), or vice versa, of the head and
is secured directly on an inner surface of a sole portion (2) in a
position nearer to a front face (3) or wherein a forward half area
(F) of the sole portion (2) as viewed from above, that is nearer to
a face member (3') of the head, has a thickness two or more times
greater in at least a portion thereof than an average thickness of
a rearward half area (R) of the sole portion, that is nearer to a
back side (10).
Inventors: |
Hasebe, Yuu; (Tokyo, JP)
; Shimasaki, Hirato; (Tokyo, JP) ; Kubota,
Makoto; (Tokyo, JP) ; Mikame, Daisuke;
(Saitama-ken, JP) ; Imamoto, Yasunori; (Tokyo,
JP) |
Correspondence
Address: |
SUGHRUE, MION, ZINN, MACPEAK & SEAS, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
WASHINGTON
DC
20037-3213
US
|
Family ID: |
26372798 |
Appl. No.: |
09/804195 |
Filed: |
March 13, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09804195 |
Mar 13, 2001 |
|
|
|
09238929 |
Jan 28, 1999 |
|
|
|
Current U.S.
Class: |
473/349 ;
473/324 |
Current CPC
Class: |
A63B 2053/0491 20130101;
A63B 53/0433 20200801; A63B 53/04 20130101; A63B 60/00 20151001;
A63B 53/0466 20130101; A63B 53/0408 20200801; A63B 2209/00
20130101 |
Class at
Publication: |
473/349 ;
473/324 |
International
Class: |
A63B 053/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 30, 1998 |
JP |
10-034008 |
May 12, 1998 |
JP |
10-128792 |
Claims
What is claimed is:
1. A golf club head of 250 cc or more in volume and having a hollow
construction, including a bar-like gravity adjusting piece
extending longitudinally from a toe towards a heel, or vice versa,
of the head and secured directly on an inner surface of a sole
portion in a position nearer to an inner surface of a front
face.
2. A golf club of 250 cc or more in volume and having a hollow
construction, including three gravity adjusting pieces: a piece (A)
secured directly on an inner surface of a sole portion of the head
in a position nearer to a toe portion, a piece (B) secured directly
on the sole inner surface in a position nearer to a back side of
the head, and a piece (C) secured directly on the sole inner
surface in a position nearer to a heel portion, these gravity
adjusting pieces being in a weight relationship of
A+B.ltoreq.C.
3. A golf club head of 250 cc or more in volume and having a hollow
construction, in which an arcuate length (l.sub.1) from a front
edge of a crown portion of the head to a front edge of a sole
portion, a circumferential length (l.sub.2) from the crown front
edge through the back side to the sole front edge, and a gravity
depth (D) of the head in a cross section of the head in the
direction of the head width at least in a sweet area of a front
face, are in a relationship of (l.sub.2/l.sub.1) .times.D
.ltoreq.100 in the cross section.
4. The golf club head as set forth in claim 3, wherein there is
formed on a portion of the cross section that will be the sole
portion of the head a generally horizontal surface of 50 mm or less
in width measured from a leading edge of the head that will be
placed on the ground during addressing.
5. A golf club head having a hollow construction, a sole portion in
the forward area, that is nearer to a front face of the head from a
half of a head width being thicker than a sole portion in the
rearward area, that is nearer to a back side of the head from the
half of the head width.
6. A golf club head having a hollow construction, a forward half
area of a sole portion of the head as viewed from above, that is
nearer to a front face of the head, having a thickness two or more
times greater in at least a portion thereof than an average
thickness of a rearward half area of the sole portion, that is
nearer to a back side of the head.
7. The golf club head as set forth in claim 6, wherein the forward
area of the sole portion has a width smaller than a half of the
sole width from the leading edge of the front face to the back side
end.
8. The golf club head as set forth in claim 6 or 7, wherein the
total area of the thick portion of the froward area is 25% or more
of the area of the forward area.
9. The golf club head as set forth in any of claims 6 to 8, wherein
portions of the forward area that are nearer to the toe and heel,
respectively, are thick.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally concerns a golf club head.
More particularly, the present invention relates to an optimally
positioning the center of gravity of a hollow-construction golf
club head made of a metallic material such as titanium, titanium
alloy, stainless steel or similar.
[0003] 2. Description of the Prior Art
[0004] It can be said that the performance of a golf club head,
namely, the ball distance traveled and traveling direction, greatly
depends upon the position of the center of gravity and moment of
inertia of the golf club head. Recently, there are many available
types of golf club heads made of metallic materials having high
specific strength, respectively, and each having an increased
volume and reduced weight. In these situations, many proposals have
been made to review and improve the shape and structure of the golf
club heads in connection with the problems of the center of gravity
position and the moment of inertia.
[0005] Generally, the geometry of the golf club head center of
gravity includes parameters such as gravity height, depth and
distance (a minimum distance of the center of gravity from the
extension of the shaft axis), etc. Therefore, a metallic golf club
head of the hollow-construction is designed with major
consideration to such parameters of the center of gravity to
optimally position the center of gravity for a player's skill and
usage of the golf club.
[0006] Indeed, the conventional golf club heads manufactured based
on the above proposals, for example, hollow-configuration large or
"jumbo" heads made of such a metal having a high specific strength
as titanium, for example, had implemented an increased inertia of
moment about the center of gravity and also increased spins of a
golf ball struck with such a golf club head, thereby allowing
average skilled golfers to enjoy an easier swinging of the golf
club and increased distance of ball flight. For these purposes, the
golf club head was designed for the center of gravity to be lower
and deeper in the head. The golf club with such a head will perform
its designed function when used by an average skilled golf player
who can swing the head at a speed not so high. However, when a golf
ball is struck with such a golf club by golfers having middle and
upper grades of skill who can swing the club head at a higher speed
and at a high ratio of meeting the sweet area of the head, too many
back spins will be imparted to the golf ball more frequently when
unnecessary, which is not any advantage for the skilled
players.
[0007] Also if the entire sole portion of the head is designed
rather more thicker than the rest to have a low gravity, the
vertical moment of inertia of the head about an axis passing
through the head center of gravity and parallel to the ground will
be unbalanced, so that striking a golf ball at an upper portion of
the front face will possibly result in a direction of ball flight
not intended or a high, weak ball not traveling a long distance.
Also even if other than the sole portion is designed to be more
lightweight by wall thinning, using a lighter material or
otherwise, the head has to be balanced by distributing, to the sole
portion, most of the corresponding weight thus reduced, thus the
head cannot be designed to be larger.
[0008] Furthermore, it has been proposed to position only the
center of gravity nearer to the front face of the golf club head.
In this case, however, since no consideration is given to the
gravity height, the center of gravity is positioned higher as it is
placed nearer to the front face of the head. The golf club head
thus designed will have characteristics suitable only for the
highly skilled golf players including professional golfers.
SUMMARY OF THE PRESENT INVENTION
[0009] Accordingly, the present invention has an object to overcome
the above-mentioned drawbacks of the prior art by providing a golf
club head having a low gravity maintaining in balance the moments
of inertia in different directions and characteristics suitable for
many different golfers ranging in grade of skill from average to
upper.
[0010] According to the present invention, there is provided a golf
club head of 250 cc or more in volume and having a hollow
construction, including a bar-like gravity adjusting piece
extending longitudinally from a toe towards a heel, or vice versa,
of the head and secured directly on an inner surface of a sole
portion in a position nearer to a front face.
[0011] According to the present invention, there is also provided a
golf club of 250 cc or more in volume and having a hollow
construction, including three gravity adjusting pieces: a piece (A)
secured directly on an inner surface of a sole portion of the head
in a position nearer to a toe portion, a piece (B) secured directly
on the sole inner surface in a position nearer to a back side of
the head, and a piece (C) secured directly on the sole inner
surface in a position nearer to a heel portion, these gravity
adjusting pieces being in a weight relationship of
A+B.ltoreq.C.
[0012] According to the present invention, there is provided a golf
club head of 250 cc or more in volume and having a hollow
construction, in which an arcuate length (l.sub.1) from a front
edge of a crown portion of the head to a front edge of a sole
portion, a circumferential length (l.sub.2) from the crown front
edge through the back side to the sole front edge and a gravity
depth (D) of the head in a cross section of the head in the
direction of the head width at least in a sweet area of a front
face, are in a relationship of(l.sub.2/l.sub.1).times.D.ltoreq.100
in the cross section.
[0013] According to the present invention, a gravity adjusting
piece is secured in a predetermined position on the inner surface
of the sole portion of the head to adjust the position of head
center of gravity. The gravity adjusting piece has a bar-like shape
extending on the inner surface of the sole portion in a position
nearer to the front face of the head from the toe portion to the
heel portion. Disposing the gravity adjusting piece allows to
position the center of gravity nearer to the front face and lower
towards the sole portion (namely, shallow and low gravity), thereby
permitting to drastically reduce back spins imparted to a golf ball
when struck with the golf club head, and increase the initial angle
of ball lifting. Thus, the reduced distance of ball flight
frequently experienced by ordinary golfers can be prevented. Also,
two such bar-like gravity adjusting pieces may be disposed
separately, one in a position near the toe of the head and the
other near the heel, to shift the center of gravity towards the
front face of the head and increase the moment of inertia about a
vertical axis through the center of gravity. That is, the center of
gravity is placed nearer to the front face while being kept low so
that appropriate back spins are imparted to the golf ball struck
with the club head, resulting in an increased distance of ball
flight and the golf ball can be hit with an increased accuracy
owing to the increased moment of inertia. Therefore, the golf club
head according to the present invention shows appropriate
characteristics suitable for various golfers having average, middle
and high grades of skill.
[0014] Furthermore, there are disposed on the inner surface of the
sole potion two gravity adjusting pieces (A) and (C) separately
near the head front face while another piece (B) near the back side
such that these pieces are in the relationship in weight of
A+B.ltoreq.C. Thus, the moment of inertia about a horizontal axis
extending through the center of gravity from the heel to toe of the
head is increased, contributing to an inhibited variation of the
loft angle of the head when striking a golf ball with the head. It
is expectable that the golf ball will fly over a distance
corresponding to the loft angle. Also, the moment of inertia about
the axis of the club shaft is decreased, so the golfers of middle
and high skill can well control the golf club head.
[0015] These objects and other objects, features, aspects and
advantages of the present invention will become more apparent from
the following detailed description of the present invention when
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a sectional view taken along the line A-A in FIG.
2, of a first embodiment of the golf club head according to the
present invention;
[0017] FIG. 2 is a plan view of the golf club head in FIG. 1;
[0018] FIG. 3 is a sectional view taken along the line B-B in FIG.
4, of a second embodiment of the golf club head according to the
present invention;
[0019] FIG. 4 is a plan view of the golf club head in FIG. 3;
[0020] FIG. 5 is a sectional view of a third embodiment of the golf
club head according to the present invention;
[0021] FIG. 6 is a sectional view of a fourth embodiment of the
golf club head according to the present invention;
[0022] FIG. 7 is a sectional view of a fifth embodiment of the golf
club head according to the present invention;
[0023] FIG. 8 is a plan view of the sole portion of the golf club
head;
[0024] FIG. 9 is a sectional view taken along the line C-C in FIG.
8; and
[0025] FIG. 10 is a plan view of the sole portion of another
embodiment of the golf club head according to the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Referring now to the drawings, the preferred embodiments of
the present invention are illustrated. Wherever possible, the same
or like reference numerals are used to throughout the drawings to
refer to the same or like parts.
[0027] FIGS. 1 and 2 show together the first embodiment of a golf
club head of the present invention. In this embodiment, a head body
is generally indicated with a reference 1. It has a hollow
construction made as a whole of a titanium alloy, and includes a
sole portion 2 and a front face 3 having a leading edge 5 by those
which a shell-like body 6 is formed. A prismatic gravity adjusting
piece 4 made of titanium and having a width of 20 mm, a length of
50 mm and a weight of 20 g, for example, is welded to the inner
surface of the sole portion 2 in a position nearer to the front
face portion 3 and 15 mm off the leading edge 5. The front face 3
of the head body 1 is 110 mm long and 49 mm high. The shell-like
body 6 having a face member welded to the front thereof is 90 mm
wide (including the thickness of the face member). In the head of
this embodiment, the gravity depth D (length extended from the head
center of gravity perpendicularly to the front face portion 3) is
set 25 mm and the gravity height H is set 20 mm, for example.
[0028] FIGS. 3 and 4 show together the second embodiment of a golf
club head according to the present invention. In this embodiment,
the golf club head body 1 is made of titanium alloy and has a
hollow-construction as in the first embodiment. Cubic gravity
adjusting pieces 4 (A, B and C) are disposed on the inner surface
of the sole portion 2. The two cubic gravity adjusting pieces 4 (A
and C) are disposed symmetrically with respect to a line B-B
passing through the center of the front face 3 of the head 1 and
perpendicular to the front face 3. They are located nearer to the
front face 3 in positions, respectively, 20 mm off the leading edge
5, one by the side of the toe portion 7 and the other by the side
of the heel portion 8, as will seen from FIG. 4. A further cubic
gravity adjusting piece 4 (B) is also disposed on the
above-mentioned line B-B. It is located nearer to a back side
portion of the head 1 in a position 69 mm from the leading edge 5.
Of the two gravity adjusting pieces 4 (A and C), the one 4 (A) is
made of titanium, has vertical and horizontal dimensions both of 15
mm and a weigh of 9 g, and the other 4 (C) is also made of
titanium, has a vertical dimension of 25 mm and horizontal
dimension of 18 mm and a weigh of 18 g. The gravity adjusting piece
4 (B) is also made of titanium, has a vertical dimension of 20 mm
and horizontal dimension of 10 mm and a weight of 8 g. Note that
the major dimensions of this head are same as those of the head in
the first embodiment shown in FIG. 1. The gravity adjusting pieces
4 (A and C) and (B) are adjusted in weight to satisfy the
relationship of A+B.ltoreq.C for no increase of the gravity
distance, such that the golfers having middle to upper grades of
skill can control the club head more easily. In this embodiment,
the gravity depth D is set 27 mm and gravity height H is set 20
mm.
[0029] FIG. 5 shows a sectional view of the third embodiment of a
golf club head according to the present invention. The head has a
hollow construction made of titanium alloy. The head body 1 has a
cross section taken in the direction of head width. The cross
section is basically defined by a triangle (.DELTA.XYZ) formed by
the end of the back side as vertex X and a line YZ through the
front face 3 as base. That is to say, the rearward portion of the
head from the front face 3 is just an outward inflation of the
triangle XYZ. It is assumed here that an arcuate length of the
front face 3 is l.sub.1, a circumferential length of the portion of
the head body 1 except for the front face 3 (namely, including the
crown and sole portion) is l.sub.2 and a desired gravity depth is
D. The front face length and the circumferential length are set to
meet a relationship of (l.sub.2/l.sub.1).times.D .ltoreq.100. The
sole portion 2 has, near the front face 3, a horizontal narrow
surface 2A having a width of 35 mm and extending from the toe 7 to
the heel 8, which will assure a stable placement of the head on the
ground when addressing. The horizontal surface 2A should preferably
be 50 mm or less wide. If the width exceeds 50 mm, the gravity
depth D will be deeper in the head body 1. In this embodiment, the
gravity depth D is set 26 mm and the face height is 48 mm (the
arcuate length l.sub.1=49 mm), and the circumferential length
l.sub.2 is set 177 mm to meet the dimensional relationship of
(l.sub.2/l.sub.1).times.D=93.9<100. Since the cross section
taken in the direction of head width at least in the sweet area has
the triangular form, the head weight is distributed rather near the
front face 3. Thus the center of gravity C.G. is located near the
front face 3 and at a low position (20 mm) near the sole portion 2.
In the cross section taken in the direction of head width in the
sweet area of the front face 3, the arcuate length l.sub.1 of the
front face 3 from the front edge of a crown portion 9 to that of
the sole portion 2, the circumferential length l.sub.2 of the head
body 1 from the front edge of the crown portion 9 to the front edge
of the sole portion 2 via the back side, and the gravity depth D of
the head, are set to meet the relationship of
(l.sub.2/l.sub.1).times.D .ltoreq.100. In this golf club head, the
center of gravity is positioned by defining the cross sectional
shape of the head in the direction of head width. At least in the
cross section in the sweet area of the front face 3, there is
defined a relationship between the height of the front face 3 (the
arcuate length) and the circumferential length of the head body 1
open at the front face 3. Namely, for the center of gravity
positioned nearer to the front face 3, the height of the front face
3 has to be increased and the above-mentioned circumferential
length of the head body 1 has to be reduced. The above relationship
of (l.sub.2/l.sub.1).times.D .ltoreq.100 was found by the Inventor
through the measurement and analysis of the dimensions and gravity
positions of various types of golf club heads. For a given or
desired gravity depth, this relationship can be used to determine a
relationship between a height of the front face 3 and
circumferential length of the head body 1, thereby permitting to
roughly design a due shape of the head section for the desired
gravity depth. By determining details within this rough design
framework, it is possible to determine a sectional shape of the
golf club head in which the head weight is distributed mainly near
the front face 3, namely, the center of gravity is also near the
front face 3.
[0030] With the golf club head with the sole portion 2 having the
generally horizontal surface 2A of 50 mm or less in width as
measured from the leading edge 5 as in the above, the user can
easily set the head in the direction of his target, namely, he will
be able to easily address the head. In this embodiment, the width
of the horizontal surface 2A is set 50 mm or less as measured from
the leading edge 5. If the width is more than 50 mm, the center of
gravity of the head will shift towards the rear, namely, the center
of gravity will be disadvantageously deeper.
[0031] FIG. 6 is a sectional view of the fourth embodiment of the
present invention, taken along a line through the center of the
front face 3. In this embodiment, the sole portion 2 is thicker in
a forward portion 2B thereof nearer to the front face 3 than a
rearward portion as shown. The thicker portion 2B is generally a
forward half of the sole portion 2, corresponding to a forward half
of the head body 1. Thus, the weight of the sole portion 2 is
distributed mainly near the front face 3 so that the center of
gravity can be near the front face 3. In this case, the gravity is
also positioned lower since the shift of the head weight to the
front face side is conducted by the sole portion 2 itself.
[0032] In the aforementioned embodiments, the gravity depth D
should be preferably 28 mm or less, gravity height H' (a minimum
distance from the center of gravity on the front face 3 to the
ground when the sole portion 2 is placed on the grounding during
normal addressing) be 26 mm or less.
[0033] FIG. 7 is a sectional view of the head body 1 of a fairway
wood according to the fifth embodiment of the present invention.
The head is wholly made of stainless steel. More particularly, the
sole portion 2 and other portion of the head body 1 are separately
formed by casting. The sole portion 2 is welded at a position
indicated with a reference 11 to the head body 1. The reference
numeral 3' indicates a face member whose lower end is the leading
edge 5. The crown portion 9 extends from the top end of the face
member 3' to the a back side 10. The sole portion 2 includes a
forward portion F near the face member 3' and a rearward portion R
near the back side 10. In this embodiment, at least a portion of
the forward portion F has a thickness two times or more greater
than the average thickness of the rear portion R. The sole portion
2 in a plan view is defined as the outside surface of the head
bottom portion gained by projecting an area surrounded by a
vertical (imaginary) surface passing through a crossing line formed
by intersection of said outside surface and the side face of the
head, and the leading edge 5 of the front face 3 to the horizontal
plain, when normally addressing a golf club with a due lie angle.
The width of the forward portion F is obtained as an average width
gained by measuring the length vertical to the front face 3 in the
direction parallel to the sole width at respective points from the
toe to heel. In the golf club head where the sole portion 2 is
divided two part, namely the forward portion F and reward portion
R, and at least a portion of the forward portion F is two times or
more greater than the average thickness of the rearward portion R,
the weight distributed on the sole portion 2 is concentrated at the
forward portion F nearer to the front face 3 to lower the center of
gravity. The center of gravity is positioned near the face member
3' so that the center of gravity on the front face 3, defined as a
point where a line passing through the center of gravity of the
head intersects perpendicularly the front face 3, is set at a lower
position. Therefore, it will be impossible that the vertical moment
of inertia is unbalanced by excessively increasing the weight of
the sole portion 2. A low gravity can be obtained with an
appropriate weight of the sole potion 2 without inducing unbalance
of the vertical moment of inertia owing the excessive sole weight.
Also, the mass removed from the sole portion 2 can be distributed
to the crown portion, perimeter, the face member 3', etc. to make a
further large head.
[0034] FIG. 8 is a plan view of the sole portion 2 of the fairway
wood club head in FIG. 7 when the head is normally addressed
keeping a lie angle designed for the golf club. FIG. 9 is a
sectional view of the sole portion 2, taken along the line C-C in
FIG. 8. As shown in FIGS. 8 and 9, the forward portion F of the
sole 2 is located by the side of the face member 3' from a line
(indicated with a dashed line and taken as boundary X herein)
parallel to the leading edge 5 of the front face 3 and
perpendicular to the direction of the sole width. The distance Y
from the leading edge S to the boundary X is the width of the
forward portion F and about 1/3 (22 mm) of the sole width (W=66
mm). The forward portion F has a uniform thickness. As shown in
FIG. 9, the rearward portion R of the sole portion 2 is located by
the side of the back side 10 from the boundary X. As will be seen
from FIG. 9, the thickness of the forward portion F is uniform in
that portion and two times larger than the average thickness of the
rearward portion R (average thickness of a portion from a point (x)
to (y) in FIG. 9 is 1.2 mm), thus it is 2.4 mm.
[0035] It should be noted that the front face 3 is 70 mm long and
the face member 3' is 46 mm high. The center of gravity (C. G.) of
the golf club head having the aforementioned construction according
to the present invention is positioned set in a lower position near
the face member 3' as shown in FIG. 7, so that the center of
gravity on the front face 3 is positioned low. Thus, the fairway
wood club head in this embodiment will be able to effectively lift
a golf ball high for an increased distance of flight.
[0036] FIG. 10 shows a further embodiment of the present invention.
In this embodiment, the toe and heel portions in the forward
portion F of the sole portion 2 are formed further thicker, namely,
3.0 mm. And the rest of the forward portion F is 1.2 mm thick as in
the rearward portion R. The total area of these thick toe and heel
portions is 40% of the total area of the forward portion F.
[0037] In addition to the above-mentioned effect, the
aforementioned thick toe and heel portions in the forward portion F
of the sole portion 2 increase the lateral moment of inertia about
a line passing through the head center of gravity and perpendicular
to the ground, whereby a golf ball hit with the club head will
flight stably without much deviation from an intended
direction.
* * * * *