U.S. patent application number 10/231698 was filed with the patent office on 2003-04-03 for golf club.
Invention is credited to Takeda, Hitoshi.
Application Number | 20030064824 10/231698 |
Document ID | / |
Family ID | 19087122 |
Filed Date | 2003-04-03 |
United States Patent
Application |
20030064824 |
Kind Code |
A1 |
Takeda, Hitoshi |
April 3, 2003 |
Golf club
Abstract
A high performance golf club is provided at low cost, in which
the thickness of a face portion is thinned and a sweet area is
widened to enhance resilience to golf balls. In a golf club with a
shaft 2 connected to a head 1, the head 1 is provided with a face 3
portion on a front face and a shaft connecting portion 8 on one
side, in which at least the face portion 3 is formed from spring
steel.
Inventors: |
Takeda, Hitoshi;
(Tsubame-shi, JP) |
Correspondence
Address: |
J. Rodman Steele, Jr.
Akerman, Senterfitt & Eidson, P.A.
P.O. Box 3188
West Palm Beach
FL
33402-3188
US
|
Family ID: |
19087122 |
Appl. No.: |
10/231698 |
Filed: |
August 29, 2002 |
Current U.S.
Class: |
473/342 |
Current CPC
Class: |
A63B 53/047 20130101;
A63B 53/0408 20200801; A63B 53/0466 20130101; A63B 53/0487
20130101; A63B 60/00 20151001; A63B 53/04 20130101; A63B 53/0416
20200801 |
Class at
Publication: |
473/342 |
International
Class: |
A63B 053/04 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 29, 2001 |
JP |
2001-259808 |
Claims
What is claimed is:
1. A golf club with a shaft connected to a head provided with a
face portion on a front face and a shaft connecting portion on one
side, wherein at least said face portion is formed from spring
steel.
2. A golf club according to claim 1, wherein the thickness of said
face portion is 2.5 mm or less.
3. A golf club according to claim 1, further comprising a recess
portion formed on a rear side of said head, and wherein said head
comprises: a head body including a window hole on a front face
thereof, corresponding to said face portion, said window hole
extending to communicate with the recess portion; a face plate
fixed firmly to this window hole; is and a depressed portion as an
undercut portion formed on the face side on a lower inner surface
of the recess portion
4. A golf club according to claim 2, further comprising a recess
portion formed on a roar side of said heads and wherein said head
comprises: a head body including a window hole on a front face
thereof, corresponding to said face portion, said window hole
extending to communicate with the recess portion; a face plate
fixed firmly to this window hole; and a depressed portion as an
undercut portion formed on the face side on a lower inner surface
of the recess portion.
5. A golf club according to claim 1, further comprising a rear
shell formed on a rear side of said head via a hollow portion,
wherein said head comprises: a head body including a window hole on
a front face thereof, corresponding to the face portion, said
window hole extending to communicate with the hollow portion; a
face plate fixed firmly to this window hole; and a depressed
portion as an undercut portion formed on the face side on a lower
inner surface of the hollow portion.
6. A golf club according to claim 2, further comprising a rear
shell formed on a rear side of said head via a hollow portion,
wherein said head comprises: a head body including a window hole on
a front face thereof, corresponding to the face portion, said
window hole extending to communicate with the hollow portion; a
face plate fixed firmly to this window hole; and a depressed
portion as an undercut portion formed on the face side on a lower
inner surface of the hollow portion.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a golf club.
[0003] 2. Description of the Related Art
[0004] Hitherto, low carbon steel such as S20C (carbon steel for
mechanical structure), that is, so-called soft iron, is in wide use
as an iron-based material for golf club heads. If golf club heads
are manufactured by a forging process using such soft iron, there
can be obtained golf clubs giving such a good feeling at the time
of striking golf balls.
[0005] On the other hand, it is generally known that the thinning
of a face is effective in order to enlarge a sweet area which is a
certain area on a face that realizes comparatively long carry of
golf balls when balls are struck thereon, or to enhance the
repulsive force to golf balls. However, as golf clubs made of soft
iron have such a low durability of the material itself against
strikes by golf balls, the thinning of a face causes dents on a
surface of the face by repeated strikes by golf balls. Accordingly,
there has been a lower limit of about 3.0 mm in the thickness of a
face.
[0006] A conventional technique to thin a face, overcoming such
drawback is disclosed in Japanese Un-Examined patent publication
No.7-308410, in which marageing steel is used as a material for
constituting a face. Since marageing steel has extremely high
strength, the use of maragening steel enables a face to be thinner
than that in the prior art. However, marageing steel contains as
much as 30% or more additive elements, so that it is an extremely
expensive material, thus leading to a drawback that the use of the
material results in golf club products becoming too expensive.
SUMMARY OF THE INVENTION
[0007] Accordingly, it is an object of the present invention to
solve the abovementioned problems, providing a high performance
golf club, at low cost, with a thinned face portion, a widened
sweet area and high resilience to golf balls.
[0008] According to a first aspect of the invention there is
provided a golf club with a shaft connected to a head provided with
a face portion on a front face and a shaft connecting portion on
one side, wherein at least said face portion is formed from spring
steel.
[0009] According to the construction of the first aspect, a high
performance golf club can be provided at a low price, wherein the
face portion can be thin due to excellence of spring steel in
fatigue strength and further spring steel has a low price due to a
small quantity of additional elements so that a sweet area can be
widened to enhance resilience to golf balls.
[0010] The invention according to a second aspect is a golf club
according to the first aspect, wherein thickness of said face
portion is 2.5 mm or less.
[0011] According to the construction of the second aspect, a high
performance golf club can be provided, wherein a sweet area can be
widened to enhance resilience to golf balls.
[0012] The invention according to a third aspect is a golf club
according to the first or the second aspect: wherein a recess
portion is formed on a rear side of said head and said head
comprises, a head body forming a window hole in a front face
thereof corresponding to said face portion so as to connect the
window hole to said recess portion, and a face member firmly fixed
to said window hole, while an undercut portion is formed on said
face portion side of an lower inner surface of said recess
portion.
[0013] According to the construction of the third aspect, a high
performance golf club can be provided, wherein a sweet area can be
widened and resilience can be enhanced by effective deflection of
the face portion due to elimination of metallic parts from a near
portion to the face portion.
[0014] The invention according to a fourth aspect is a golf club
according to the first or the second aspect, wherein a rear shell
is formed at a rear side of said head via a hollow portion and said
head comprises, a head body forming a window hole in a front face
thereof corresponding to said face portion so as to connect the
window hole to said hollow portion, and a face member firmly fixed
to said window hole, while an undercut portion is formed on said
face portion side of an lower inner surface of said hollow
portion.
[0015] According to the construction of the fourth aspect, a high
performance golf club can be provided, wherein a sweet area can be
widened and resilience to golf balls can be enhanced by effective
deflection of the face portion due to elimination of metallic parts
from near portions to the face portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] For a more complete understanding of the present invention,
reference is now made to the following description taken in
conjunction with the accompanying drawings, in which:
[0017] FIG. 1 is a front view illustrating a first embodiment of
the present invention.
[0018] FIG. 2 is a cross-sectional view illustrating the first
embodiment of the present invention.
[0019] FIG. 3 is an exploded front perspective view illustrating
the first embodiment of the present invention.
[0020] FIG. 4 is an exploded roar perspective view illustrating the
first embodiment of the present invention.
[0021] FIG. 5 is a perspective view showing a golf club at the time
of machining according to the first embodiment of the present
invention.
[0022] FIG. 6a is a cross-sectional view showing a golf club at the
time of welding, while FIG. 6b a partially enlarged section thereof
according to the first embodiment of the present invention
[0023] FIG. 7 is a cross-sectional view illustrating a second
embodiment of the present invention
[0024] FIG. 8 is a cross-sectional view illustrating a third
embodiment of the present invention
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Hereunder is a description of embodiments of the present
invention with reference to the accompanying drawings. FIG. 1 to
FIG. 6 show an iron type golf club that is a first embodiment,
which is provided with a head 1 and a shaft 2. The head 1 is, on a
front face thereof, formed with a face 3, that is a face portion
for striking golf balls (not shown in the drawings), while a top 4
on an upper portion of the face 3, a sole 5 on a lower portion
thereof, a toe 6 on one side, and a heel 7 on the other side of the
face 3 are formed, respectively. Further, a shaft connecting
portion 8 referred to as a hose) or the like is protruded obliquely
upwardly on the upper portion of the heel 7, while a lower end of
the shaft 2 is connected to the shaft connecting portion 8.
[0026] Further, a recess portion 9 is formed in order to enhance
moment of inertia by distributing weight on the peripheral portion
of a rear side of the head 1. This recess portion 9 is formed with
a bottom surface 9A opposing the face 3, an upper inner surface 9B
on an upper portion, a lower inner surface 9C on a lower portion, a
first side inner surface 9D on one side and a second side inner
surface 9E on the other side. Further, in the drawing, numeral 10
denotes lateral grooves called score lines or the like formed on
the face 3.
[0027] The head 1 comprises: a head body 1A including the aforesaid
shaft connecting portion 8 on the other side and a window hole 11
on a front face thereof corresponding to the face 3, said window
hole 11 extending to communicate with the bottom surface 9A of the
recess portion 9; and a face plate 14 or a face member, fixed
firmly to this window hole 11. A peripheral portion 12 of the
window hole 11 is arranged via a step portion 13 more outside than
the upper inner surface 9B, the lower inner surface 9C, the first
side inner surface 9D and the second side inner surface 9E, of the
bottom surface 9A. Further, the face plate 14 is firmly fitted into
the window hole 11 with the rear surface thereof being abutted
against the bottom face 15 of the step 13. Moreover, a depressed
portion 16, that is an undercut portion, is formed on the face 3
side on the lower inner surface 9C of the recess portion 9 which
forms a cavity. This depressed portion 16 is depressed toward the
sole 5 and formed from the first side inner surface 9D to the
second side inner surface 9E on the lower inner surface 9C. The
depth D of the portion 16, that is, a distance D between the
deepest surface of the depressed portion 16 and the lower inner
surface 9C is set at 7 mm or more, preferably at 10 mm or more. In
the meantime, this depressed portion 16 is aimed at deepening the
center of gravity of the head, enlarging a sweet area, and making
it easier to raise golf balls, and further allowing the face 3 to
be deflected efficiently by removing metallic parts from near the
face 3.
[0028] It should be noted herein that the head body 1A is formed
from S20C that is low carbon steel by forging, using a metal mold.
The face plate 14 is formed to a thickness of 2.5 mm by applying
blank processing (contour punching processing) to spring steel,
i.e., rolled steel plate of 2.5 mm thickness. It is preferable that
the thickness of the face plate 14 is as thin as possible as the
sweet area can be widened. As a result of an experiment, however,
it has turned out that when the thickness of the face plate 14 is
made lass than 15 mm, even the comparatively small number of times
of strikes causes depression on the face plate 14. Further, it has
turned out that the thickness of the face plate 14 should
preferably be 2.0 mm or more in order to insure strength against
repeated strikes. On the other hand, if the thickness of the face
plate 14 is more than 3.0 mm, it brings about little or no effect
to widen the sweet area, and thus it is not preferable. However,
when it is 2.5 mm or less, marked effect to widen the sweet area
has been noted. Consequently, the thickness of the face plate 14
may be specified as 3.0 mm or less, preferably as 1.5 to 2.5 mm,
more preferably as 2.0 to 2.5 mm. The thickness of the face plate
14 may be varied according to the thickness of rolled steel plate
of SUP 10 used for the face plate 14. Incidentally, the face plate
14 may be formed by forging.
[0029] Whilst spring steel is given a notation of SUP in JIS
standard, it is an abbreviation for Steel Use Spring. The kinds,
chemical composition and mechanical properties of spring steel are
as shown in Tables 1 and 2. Any kind of the listed spring steel
contains as less as 5% or less additive elements, and thus it is
inexpensive.
[0030] SUP 10 used in the present embodiment is used as a coil
spring or the like, having such a mechanical strength that proof
stress is 1,079N/mm.sup.2 or more, tensile strength 1,226N/mm.sup.2
or more, and hardness (HD) 363 to 429 by JIS standard. On the other
hand, although not shown in tables, S20C has such a mechanical
strength that yield point is 245N/mm.sup.2 or more, tensile
strength 400N/mm.sup.2 or more, and hardness (HB) 116 to 174 by JIS
standard. Consequently, mechanical strength of S20C is considerably
lower than that of SUP 10.
1TABLE 1 Chemical Composition of Spring Steel (JIS G4801) JIS
Chemical Composition (%) Symbol C Si Mn P S Cu Cr Mo V B SUP3
0.75-0.90 0.15-0.35 0.30-0.60 0.035 0.035 0.30 -- -- -- -- or less
or less or less SUP6 0.56-0.64 1.50-1.80 0.70-1.00 0.035 0.035 0.30
-- -- -- -- or less or less or less SUP7 0.56-0.64 1.80-2.20
0.70-1.00 0.035 0.035 0.30 -- -- -- -- or less or less or less SUP9
0.52-0.60 0.15-0.35 0.65-0.95 0.035 0.035 0.30 0.45-0.95 -- -- --
or less orless or less SUP9A 0.56-0.64 0.15-0.35 0.70-1.00 0.035
0.035 0.30 0.70-1.00 -- -- -- or less or less or less SUP10
0.47-0.55 0.15-0.35 0.65-0.95 0.035 0.035 0.30 0.80-1.10 --
0.15-0.25 -- or less or less or less SUP11A 0.56-0.64 0.15-0.35
0.70-1.00 0.350 0.035 0.30 0.70-1.00 -- -- 0.0005 or less or less
or less or less SUP12 0.51-0.59 1.20-1.60 0.60-0.90 0.035 0.035
0.30 0.60-0.90 -- -- -- or less or less or less SUP13 0.56-0.64
0.15-0.35 0.70-1.00 0.35 0.035 0.30 0.70-0.90 0.25-0.35 -- -- or
less or less or less
[0031]
2TABLE 2 Mechanical properties of Spring Steel (JIS G4801)
Mechanical Properties Proof Elongation Reduction Stress Tensile %
of Area % JIS Thermal Treatment(.degree. C.) 0.2% Strength No 4 or
No 7 No 4 Hardness Symbol Quenching Tempering N/mm.sup.2 N/mm.sup.2
Test Piece Test Piece (HB) Example SUP3 830-860 450-500 834 1079 8
or more -- 341-401 Leaf Oil-Cooling or more or more Spring SUP6
830-860 480-530 1079 1226 9 or more 20 363-429 Leaf Oil-Cooling or
more or more or more Spring, SUP7 830-860 490-540 1079 1226 9 or
more 20 363-429 Coil Oil-Cooling or more or more or more Spring
SUP9 830-860 460-510 1079 1226 9 or more 20 363-429 Oil-Cooling or
more or more or more SUP9A 830-860 460-520 1079 1226 9 or more 20
363-429 Concrete Oil-Cooling or more or more or more Ball SUP10
830-860 470-540 1079 1226 10 or more 30 363-429 Coil Oil-Cooling or
more or more or more Spring SUP11A 830-860 460-520 1079 1226 9 or
more 20 363-429 Leaf Oil-Cooling or more or more or more Spring,
Coil Spring SUP12 830-860 510-570 1079 1226 9 or more 20 363-429
Coil Oil-Cooling or more or more or more Spring SUP13 830-860
510-570 1079 1226 10 or more 31 363-429 Large Oil-Cooling or more
or more or more Leaf Spring, Coil Spring Remarks: The numerical
values in the above table were obtained by testing 25 mm standard
test pieces which were thermally treated within the temperature
ranges shown in the above table.
[0032] Next is a description of a method for manufacturing a golf
club of the present embodiment. First, a prototype (not shown in
the drawings) of the head body 1A is formed from a metallic raw
material (not shown in the drawings) of low carbon steel S20C by
forging, using a metal mold. Thereafter, as shown in FIG. 5, the
recess portion 9, window hole 11 and depressed portion 16 are
processed to be formed by machining tools 20 such as cutting or
grinding tools, including an end mill and a turning tool. The
depressed portion 16 is formed by cutting or grinding the front
side of the lower inner surface 9C with the machining tool 20 to be
put into the window hole 11 from a front side of a face. Further, a
small convex portion 18 is formed overall or partially along the
peripheral portion 12 of the window hole 11, that is, on the top 4
and the sole 5 sides along the peripheral portion 12 in the present
embodiment. A height X of this convex portion 18 is 1 mm or less,
preferably about 0.8 mm, and a width Y thereof is 1 mm or less,
preferably 0.5 mm.
[0033] On the other hand, spring steel SUP 10 of 2.5 mm thickness
rolled steel plate is formed into a shape of the face plate 14
through blank process (contour punching process). Then, a chamfered
portion 19 is formed on a fringe of a rear portion of the face
plate 14 so that an air gap 22 with a triangle profile, as shown in
the partially enlarged cross sectional view of FIG. 6, is formed
such that an angle of the bottom surface 10 to the chamfered
surface may be 45 degrees or more, for example, 80 degrees and the
upper side of the triangle may be in the order of 0.5 to 1.5 mm in
length.
[0034] Thereafter, the head body 1A and the face plate 14 are
firmly fixed together by laser welding. After the face plate 14 is
fitted into the window hole 11 of the head body 1A, laser welding
is applied with a head 21 of a laser welder being pointed to the
peripheral portion 12 of the window hole 11. At this time, the
convex portion 18 is also fused while the welded center portion is
raised but both sides thereof sink to form depressed areas.
However, as the fused metal of the convex portion 18 flows into the
depressed areas so that the depressed areas can be prevented from
occurring. In the meantime, whilst the convex portion 18 has height
X of 1 mm or less and width Y of 1 mm or less, laser is likely to
go out of focus if larger dimensions than these dimensions are
employed, thus leading to a possibility that the convex portion 18
cannot be melted well.
[0035] While welding is being performed by applying laser beam from
a front side, the air gap 22 is formed between the face plate 14
and the bottom portion 15 by the chamfered portion 19 formed in a
rear portion of the face plate 14, so that the face plate 14 has a
partially thinned portion. By applying penetration welding to the
partially thinned portion, clearance is insured for air bubbles
generated during the laser welding to go out therethrough. In this
case, air bubbles are not confined to the welded portion so that no
pin hole is formed in the welded portion. Laser welding should have
a specification such that an output is 450 W, welding speed 250
mm/minute, the number of pulses 30 pps, and depth of penetration in
the order of about 1.5 to 1.6 mm. In the meantime, the chamfered
portion 19 will do as long as the air gap 22 is formed, and thus a
shape and angle of the chamfer may be varied.
[0036] Laser welding used here is advantageous in that it brings
about fewer portions influenced by heat to produce fewer
distortions than TIG welding, enabling the welding between
different metals, requiring no weld rods so that the automation of
welding is possible, using automating programming, and that a
welding portion is V-shaped so that good welding can be performed.
Moreover, as laser beams are electromagnetic waves, the working
environment is not subject to restrictions, and laser beams can be
condensed and changed in its course by optical apparatuses (lenses
or mirrors), without constraints of machining jigs as laser beams
are not affected by electromagnetic fields, enabling the welding of
both metals and nonmetals, with no X ray being emitted from raw
materials. In this respect, electron beam welding needs vacuum
environment in general, having disadvantages for facilities and
workability. TIG welding bas drawbacks that a number of distortions
take place due to great thermal influence, time-consuming due to
manual procedure and bead lines are unstable.
[0037] Thereafter, thermal treatments of quenching and tempering
are applied to the head 1, whose strength and toughness are
thermally adjusted, while further grinding and plating or the like
are applied to finish the head 1.
[0038] Shot peening may be applied to spring steel in order to
enhance its fatigue strength further where such treatment is
suitable, provided that attention is paid not to cause deflection
in the face plate 14 as it is likely to be deflected by the stress
developed at the time of shot peening due to the thinness of the
face plate 14 in the present embodiment.
[0039] As described above, a golf club of the foregoing embodiment
is a golf club including: the head 1 with the face 3 on a front and
the shaft connecting portion 8 on one side; and the shaft 2
connected to the head 1, wherein at least said face 3 is formed
from spring steel. Consequently, the face 3 is not dented by
repeated strikes against golf balls due to the excellent fatigue
strength of spring steel even if the face 3 is made thin.
Accordingly, it is possible to make the face 3 thin, and there call
be provided a high performance golf club at a low price bit
enlarging a sweet area and enhancing resilience of the face to golf
balls owing to spring steel containing such a small quantity of
additive elements that it is inexpensive.
[0040] According to the second aspect of the invention, as the
thickness of said face 3 is made 2.5 mm or less, a high performance
golf club can be provided, with an enlarged sweet area and enhanced
resilience to golf balls.
[0041] Moreover, according to the third aspect, the recess portion
9 is formed on a rear side of said head 1, said head 1 comprising:
the head body 1A including the window hole 11 an a front face
thereof, corresponding to the face 3, said window hole 11 extending
to communicate with the recess portion 9; the face plate 14 fixed
firmly to this window hole 11;and the depressed portion 16 as an
undercut portion formed on the face 3 side on the lower inner
surface 9C of the recess portion 9 Accordingly, there can be
provided a high performance golf club with an enlarged sweet area
as well as the enhanced resilience to golf balls by removing
metallic parts from near the face 3.
[0042] Next is a description of a second embodiment with reference
to FIG. 7. The same reference symbols are used for parts the same
as in the first embodiment, and detailed description thereof is
omitted, FIG. 7 shows a hollow iron type or wood type golf club of
the second embodiment of the invention. The construction of the
second embodiment is totally the same as the first embodiment
expect that a rear shell 42 is integrated with a rear side of a
head body 1 via a hollow portion 41.
[0043] According to the second embodiment of the inventions, which
corresponds to the fourth aspect of the invention, the rear shell
42 is formed in a rear side of said head 1 via the hollow portion
41, said head 1 comprising: the head body 1A including the window
hole 11 on a front face thereof, corresponding to the face 3, said
window hole 11 extending to communicate with the hollow portion 41;
the face plate 14 fixed firmly to this window hole 11;and the
depressed portion 16 as an undercut portion formed on the face 3
side on the lower inner surface 9C of the hollow portion 41.
Accordingly, there can be provided a high performance golf club
with an enlarged sweet area as well as the enhanced resilience to
golf balls by removing metallic parts from near the face 3.
[0044] Next is a description of a third embodiment with reference
to FIG. 8. The same reference symbols are used for parts the same
as in the first embodiment and detailed description thereof is
omitted. FIG. 8 shows a wood type golf club as the third
embodiment. A head 1 is a so-called metal wood that is made of
metal and hollow. The head 1 has a hollow portion 51 thereinside,
in which filling material such as polyurethane or the like may be
filled. The head 1 is constructed of three pieces, for example.
That is, the outer shell of the bead 1 comprises the face plate 14
that is a tabular face member, a body member 52 and a crown member
53. The face plate 14 forms the face 3, the crown member 53 forms
the top 4 and the body member 52 forms the sole 5 or the like other
than the formers. Further, the face plate 14, the body member 52
and the crown member 53 are joined together by means of welding or
the like.
[0045] Further, the face plate 14, the body member 52 and the crown
member 53 are formed from rolled steel plate of SUP 10 that are
spring steel, through forging or press molding. The thickness t1 of
the face plate 14 is 2.5 mm and the thickness t2 and t3 of the body
member 52 and the crown member 53 are formed thinner than the
thickness t1 of the face plate 14. As the preferable thickness of
the face 14 is the same as in the first embodiment, the description
thereof is omitted. Moreover, only the face plate 14 may be formed
from spring steel and the other members may be formed from
titanium-based alloy or low carbon steel or the like.
[0046] Incidentally, the present invention should not be limited to
the aforementioned embodiments but a variety of modifications are
possible within the scope of the present invention.
[0047] Whilst the aforementioned embodiments are described by
taking an iron type, a hollow iron type or a wood type golf club as
examples, the present invention should not be limited to these
types, but may be applied to a putter as well.
[0048] Further, although only the face member is formed from spring
steel in the first and second embodiments, the whole of the head 1
may be fabricated by forging, using spring steel. Further, spring
steel should not be limited to SUP 10 but other kinds of spring
steel may be used. Additionally, when forming the head 1 from the
face member 14 and the head body 1A, the material of the head body
1A should not be limited to S20C but may be other kinds of
iron-based materials, stainless steel and titanium alloys or the
like. Moreover, joint method between the face member 14 and the
head body 1A shall not be limited to laser welding but may be other
welding means such as TIG welding, press-fitting or fitting through
plastic deformation of materials, or bonding with an adhesive.
Alternatively, the window hole 11 and the depressed portion 16 may
be formed not by cutting or grinding but by forging at the same
time when the head body 1A is fabricated by forging. In addition,
although the small convex portion 18 is formed along the peripheral
portion 12 on the top 4 and the sole 5 side of the head body 1A in
the foregoing embodiments, the position of the convex portion 18
should not be limited to there but may be any other suitable
position in the peripheral portion 12, or otherwise, it may be
formed on a whole or partial peripheral portion of the face member
14.
* * * * *