U.S. patent application number 13/196461 was filed with the patent office on 2012-04-12 for putter head.
This patent application is currently assigned to BRIDGESTONE SPORTS CO., LTD. Invention is credited to Wataru BAN, Tadahiro NARITA.
Application Number | 20120088599 13/196461 |
Document ID | / |
Family ID | 45925561 |
Filed Date | 2012-04-12 |
United States Patent
Application |
20120088599 |
Kind Code |
A1 |
NARITA; Tadahiro ; et
al. |
April 12, 2012 |
PUTTER HEAD
Abstract
This invention provides a putter head comprising a head body and
a face insert mounted on a face surface of the head body. A notched
portion is provided in a rear surface of the face insert to extend
upward from a lower end portion.
Inventors: |
NARITA; Tadahiro;
(Chichibu-shi, JP) ; BAN; Wataru; (Chichibu-shi,
JP) |
Assignee: |
BRIDGESTONE SPORTS CO., LTD
Tokyo
JP
|
Family ID: |
45925561 |
Appl. No.: |
13/196461 |
Filed: |
August 2, 2011 |
Current U.S.
Class: |
473/329 ;
473/340 |
Current CPC
Class: |
A63B 2209/00 20130101;
A63B 53/042 20200801; A63B 60/54 20151001; A63B 53/0487 20130101;
A63B 53/0437 20200801; A63B 53/065 20130101; A63B 53/0425
20200801 |
Class at
Publication: |
473/329 ;
473/340 |
International
Class: |
A63B 53/04 20060101
A63B053/04; A63B 53/06 20060101 A63B053/06 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 7, 2010 |
JP |
2010-227748 |
Nov 10, 2010 |
JP |
2010-251887 |
Dec 17, 2010 |
JP |
2010-282035 |
Claims
1. A putter head comprising a head body and a face insert mounted
on a face surface of the head body, wherein a notched portion is
provided, in a rear surface of the face insert to extend upward
from a lower end portion.
2. The head according to claim 1, wherein the notched portion
extends from a left end of the face insert to a right end
thereof.
3. The head according to claim 1, wherein an upper edge portion of
the rear surface of the face insert abuts against a bottom wall
surface of a recessed portion provided in the face surface, and is
fixed on the head body by a screw member.
4. The head according to claim 1, wherein the notched portion is
filled with a viscoelastic material.
5. A putter head comprising a head body and a face insert mounted
on a face surface of the head body, wherein a notched portion is
provided in a rear surface of the face insert to extend downward
from an upper end portion.
6. The head according to claim 5, wherein the notched portion
extends from a left end of the face insert to a right end
thereof.
7. The head according to claim 5, wherein a lower edge portion of
the rear surface of the face insert abuts against a bottom wall
surface of a recessed portion provided in the face surface, and is
fixed on the head body by a screw member.
8. The head according to claim 5, wherein the notched portion is
filled with a viscoelastic material.
9. A putter head comprising a head body and a face insert mounted
on a face surface of said head body, wherein the face insert
comprises a plate portion disposed on the face surface, and a
bracket portion which is continuous with an upper edge of said
plate portion and extends backward along a top surface of the head
body, said bracket portion is fixed on an upper surface portion of
the head body, and a rear surface of said plate portion and the
head body are spaced apart from each other.
10. The head according to claim 9, wherein a viscoelastic material
is disposed between the rear surface of said plate portion and the
head body.
11. The head according to claim 9, wherein said bracket portion
comprises a bolt insertion hole which vertically runs therethrough,
and a bolt is screwed into the head body via said bolt insertion
hole, thereby fixing the face insert on the head body.
12. The head according to claim 9, wherein said bracket portion
comprises a depending portion which hangs over a rear surface of
the head body, a bolt insertion hole runs through said depending
portion in a front-to-back direction, and a bolt inserted in said
bolt insertion hole is screwed into the head body, thereby fixing
the face insert on the head body.
13. The head according to claim 9, wherein a groove is provided in
a top surface of the head body to engage with said bracket
portion.
14. The head according to claim 9, wherein the face insert includes
a plurality of face inserts including plate portions with different
thicknesses as spares, and one of the face inserts, which is
selected from the spares, is detachably mounted on the head
body.
15. The head according to claim 10, wherein the viscoelastic
material includes a plurality of viscoelastic materials with
different thicknesses as spares, and the viscoelastic material with
a thickness corresponding to a thickness of the face insert is
selected from the spares, and disposed between the rear surface of
said plate portion and the head body.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the putter head of a golf
putter and, more particularly, to a putter head including a face
insert mounted on the face surface of the head body.
[0003] 2. Description of the Related Art
[0004] A golf putter is a club that is mainly used to hit a ball on
a green and roll it toward a cup. Japanese Patent Laid-Open No.
2007-117635 describes a technique for mounting a face insert on the
face surface of a putter head to soften an impact feel.
[0005] Japanese Patent Laid-Open No. 2001-62008 describes a putter
head in which the lower portion of the face surface is integrated
with a synthetic resin foam to easily impart top spin to a ball.
However, a synthetic resin foam has characteristics with a strong
temperature dependence, so the effect of top spin changes
considerably depending on the air temperature.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to improve spin on
a ball.
[0007] According to an aspect of the present invention, there is
provided a putter head comprising a head body and a face insert
mounted on a face surface of the head body, wherein a notched
portion is provided in a rear surface of the face insert to extend
upward from a lower end portion.
[0008] According to another aspect of the present invention, there
is provided a putter head comprising a head body and a face insert
mounted on a face surface of the head body, wherein a notched
portion is provided in a rear surface of the face insert to extend
downward from an upper end portion.
[0009] According to still another aspect of the present invention,
there is provided a putter head comprising a head body and a face
insert mounted on a face surface of the head body, wherein the face
insert comprises a plate portion disposed on the face surface, and
a bracket portion which is continuous with an upper edge of the
plate portion and extends backward along a top surface of the head
body, the bracket portion is fixed on an upper surface portion of
the head body, and a rear surface of the plate portion and the head
body are spaced apart from each other.
[0010] Further features of the present invention will become
apparent from the following description of exemplary embodiments
with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1A is an exploded perspective view of a putter head
according to an embodiment;
[0012] FIG. 1B is a front view of the putter head shown in FIG.
1A;
[0013] FIG. 1C is a sectional view taken along a line C-C in FIG.
1B;
[0014] FIG. 2 is an enlarged sectional view taken along a line I-I
in FIG. 1B;
[0015] FIG. 3 is a perspective view of a face insert when viewed
from the rear side;
[0016] FIGS. 4 to 7 are sectional views of face inserts of putter
heads each according to another embodiment;
[0017] FIG. 8 is a perspective view showing a face insert of the
putter head shown in FIG. 7 when viewed from the rear side;
[0018] FIGS. 9 and 10 are sectional views of putter heads each
according to still another embodiment;
[0019] FIG. 11A is an exploded perspective view of a putter head
according to still another embodiment,
[0020] FIG. 11B is a front view of the putter head shown in FIG.
11A;
[0021] FIG. 11C is a sectional view taken along a line C-C in FIG.
11B;
[0022] FIG. 12 is an enlarged sectional view taken along a line
II-II in FIG. 11B;
[0023] FIG. 13 is a perspective view of a face insert when viewed
from the rear side;
[0024] FIGS. 14 to 16 are sectional views of face inserts of putter
heads each according to still another embodiment;
[0025] FIG. 17 is a sectional view of a putter head according to
still another embodiment;
[0026] FIG. 18 is a perspective view showing a face insert of the
putter head shown in FIG. 17 when viewed from the rear side;
[0027] FIGS. 19 and 20 are sectional views of putter heads each
according to still another embodiment;
[0028] FIG. 21 is a perspective view of a putter head according to
still another embodiment;
[0029] FIG. 22 is a front view of the putter head shown in FIG.
21;
[0030] FIG. 23 is a sectional view taken along a line III-III in
FIG. 22;
[0031] FIG. 24 is an exploded perspective view of the putter head
shown in FIG. 21;
[0032] FIGS. 25 to 31 are sectional views of putter heads each
according to still another embodiment;
[0033] FIG. 32 is an exploded perspective view of the putter head
shown in FIG. 31; and
[0034] FIGS. 33 and 34 are sectional views of face inserts of
putter heads each according to still another embodiment.
DESCRIPTION OF THE EMBODIMENTS
First Embodiment
[0035] This embodiment provides a putter head which imparts back
spin, that is smaller in amount than in a general putter, to a ball
upon striking the ball, to eventually facilitate creation of top
spin of the ball, and exhibits a degree of top spin, that has a
small temperature dependence.
[0036] FIGS. 1 to 3 show a putter head 1 according to this
embodiment. The putter head 1 is provided with a recessed portion
2H in the front surface (face surface) of a head body 2, and a face
insert 3 is disposed in the recessed portion 2H. In this
embodiment, the head body 2 is made of a metal such as an aluminum
alloy, a titanium alloy, a copper alloy, or stainless steel. The
face insert 3 is made of a synthetic resin such as polyester,
nylon, or urethane, or a metal such as an aluminum alloy, a copper
alloy, or stainless steel. The front surface of the face insert 3
is flush with that of the head body 2 around the recessed portion
2H. The recessed portion 2H and face insert 3 both have an
elongated, almost rectangular shape, when viewed from the front
side. The recessed portion 2H has a uniform depth as a whole.
However, the recessed portion 2H may be partly provided with a deep
portion, or conversely, a shallow portion.
[0037] A notched portion 3a is provided in the rear surface of the
face insert 3 to extend upward from the lower edge portion. The
notched portion 3a extends from the left end of the face insert 3
to its right end. The rear surface of an upper edge portion 3b on
the rear surface of the face insert 3 is a flat surface parallel to
the front surface of the face insert 3.
[0038] In this embodiment, the rear surface of the notched portion
3a is also a flat surface parallel to the front surface of the face
insert 3.
[0039] A plurality of female screw holes 3c (a total of two, left
and right female screw holes 3c in this embodiment) are provided in
the upper edge portion 3b of the face insert 3, as shown in FIG. 3.
A bolt insertion hole 5 (FIG. 2) runs through the head body 2 in
the front-to-back direction at a position that matches the female
screw hole 3c. A bolt 6 inserted in each bolt insertion hole 5 is
screwed into the female screw hole 3c, thereby fixing the face
insert 3 on the head body 2.
[0040] The face insert 3 has a horizontal dimension and vertical
dimension that is slightly smaller than the recessed portion 2H, so
a small gap 4 is formed between upper, lower, left, and right side
surfaces 3S of the face insert 3 and a peripheral surface 2S (FIG.
1A) of the recessed portion 2H. The width of the gap 4 is
preferably 0.3 to 1.5 mm and more preferably about 0.4 to 1.0 mm.
As for the size of the face insert 3, its vertical dimension is
preferably 16 to 30 mm and more preferably about 18 to 25 mm, its
horizontal dimension is preferably 50 to 150 mm and more preferably
about 70 to 100 mm, the thickness of the upper edge portion 3b is
preferably 2 to 10 mm and more preferably about 3 to 8 mm, and the
thickness of the face insert in the notched portion 3a is smaller
than that in the upper edge portion 3b by preferably 0.6 to 0.2 mm
and more preferably 0.8 to 1.4 mm. However, the size of the face
insert 3 is not limited to these specific values.
[0041] The face insert 3 is disposed in the recessed portion 2H
such that its surface opposite to the notched portion 3a becomes
the face front surface of the putter, and the upper edge portion 3b
abuts against the bottom wall surface of the recessed portion 2H.
As described above, the bolt 6 is inserted in each bolt insertion
hole 5 to screw it into the female screw hole 3c, thereby fixing
the face insert 3 on the head body 2. Thus, the putter head 1 is
formed.
[0042] A putter is formed by connecting a shaft to a hosel portion
1h of the thus formed putter head 1. Upon putting with this putter
(striking a ball on a green with the face surface), the front
surface side of the lower portion of the face insert 3 slightly
recedes upon hitting the ball, thereby easily imparting top spin to
the ball. Thus, the hit ball exhibits good rectilinear movement
characteristics.
[0043] In face inserts 3A to 3C shown in FIGS. 4 to 6,
respectively, the front surface of the notched portion 3a has an
inclination different from that of the front surface of the notched
portion 3a in the face insert 3 mentioned above. In the face insert
3A shown in FIG. 4, the front wall surface defining the notched
portion 3a is inclined more to the front toward its upper portion.
In the face inserts 3B and 3C shown in FIGS. 5 and 6, respectively,
the front wall surface defining the notched portion 3a is inclined
more to the rear toward its upper portion. Note that in the face
inserts 3, 3A, and 3B, the upper edge portion 3b of the rear
surface of the face insert and the front wall surface defining the
notched portion 3a have a stepped boundary between them, but in the
face insert 3C shown in FIG. 6, the front surface of the notched
portion 3a is formed to directly intersect with the upper edge
portion 3b. Although not shown, the front wall surface defining the
notched portion may at least partly have a curved surface.
[0044] FIG. 7 is a sectional view of the same portion as in FIG. 2
in a putter head 1A according to another embodiment, and FIG. 8 is
a perspective view of a face insert 3 of the putter head 1A when
viewed from the rear side.
[0045] In this embodiment, the notched portion 3a is filled with a
viscoelastic material 7. Rubber, an elastomer, or a soft synthetic
resin, for example, is used as the viscoelastic material 7.
[0046] The viscoelastic material 7 has the same size as the notched
portion 3a, and the rear surface of the viscoelastic material 7 is
flush with the upper edge portion 3b of the face insert 3, but the
viscoelastic material 7 may be thinner than the face insert 3.
Also, the viscoelastic material 7 may have a horizontal dimension
and vertical dimension smaller than the face insert 3.
[0047] Like the putter head 1A, when the notched portion 3a is
filled with the viscoelastic material 7, an impact sound and an
impact feel upon hitting a ball can be adjusted.
[0048] Although the front surface of the face insert is flat in the
above-described embodiments, a plurality of parallel elongated
grooves may be provided. The groove preferably has a width
(vertical dimension) of about 0.3 to 1.6 mm and a depth of about
0.05 to 1.1 mm.
[0049] Although the gap 4 is formed around the face insert 3 in the
above-described embodiments, a viscoelastic material 8 such as
rubber, an elastomer, or a synthetic resin may be disposed in the
gap 4, like a putter head 1B shown in FIG. 9. Also, like a putter
head 10 shown in FIG. 10, the face insert 3 may be formed to
tightly fit in the recessed portion 2H so as to generate no gap
4.
[0050] Like the putter heads 1, 1A, and 1B shown in FIGS. 1 to 9,
when the gap 4 or the viscoelastic material 8 is provided between
the side surfaces 3S of the face insert 3 and the peripheral
surface 2S of the recessed portion 2H, this prevents generation of
residual stress in the face insert, thus producing an effect of
obtaining rebound characteristics of the face insert, which comply
with the design: Other arrangements in FIGS. 8 to 10 are the same
as in FIG. 2, and the same reference numerals denote the same
parts.
[0051] The above-described embodiments merely give examples of the
present invention, and the present invention may be practiced in a
mode other than those shown in the accompanying drawings. For
example, the face insert may be fixed on the head body by a fixing
means such as swaging or bonding other than bolting.
Second Embodiment
[0052] This embodiment provides a putter head which imparts top
spin, that is smaller in amount than in a general putter, to a ball
upon striking the ball, to eventually facilitate creation of back
spin of the ball.
[0053] FIGS. 11 to 13 show a putter head 11 according to this
embodiment. The putter head 11 is provided with a recessed portion
12H in the front surface (face surface) of a head body 12, and a
face insert 13 is disposed in the recessed portion 12H. In this
embodiment, the head body 12 is made of a metal such as an aluminum
alloy, a titanium alloy, a copper alloy, or stainless steel. The
face insert 13 is made of a synthetic resin such as polyester,
nylon, or urethane, or a metal such as an aluminum alloy, a copper
alloy, or stainless steel. The front surface of the face insert 13
is flush with that of the head body 12 around the recessed portion
12H.
[0054] The recessed portion 12H and face insert 13 both have an
elongated, almost rectangular shape, when viewed from the front
side. The recessed portion 12H has a uniform depth as a whole.
However, the recessed portion 12H may be partly provided with a
deep portion, or conversely, a shallow portion.
[0055] A notched portion 13a is provided in the rear surface of the
face insert 13 to run downward from the upper edge portion. The
notched portion 13a extends from the left end of the face insert 13
to its right end. The rear surface of a lower edge portion 13b on
the rear surface of the face insert 13 is a flat surface parallel
to the front surface of the face insert 13.
[0056] In this embodiment, the rear surface of the notched portion
13a is also a flat surface parallel to the front surface of the
face insert 13.
[0057] A plurality of female screw holes 13c (a total of two, left
and right female screw holes 13c in this embodiment) are provided
in the lower edge portion 13b of the face insert 13, as shown in
FIG. 13. A bolt insertion hole 15 (FIG. 12) runs through the head
body 12 in the front-to-back direction at a position that matches
the female screw hole 13c. A bolt 16 inserted in each bolt
insertion hole 15 is screwed into the female screw hole 13c,
thereby fixing the face insert 13 on the head body 12.
[0058] The face insert 13 has a horizontal dimension and vertical
dimension slightly smaller than the recessed portion 12H, so a
small gap 14 is formed between upper, lower, left, and right side
surfaces 13S of the face insert 13 and a peripheral surface 12S
(FIG. 1A) of the recessed portion 12H. The width of the gap 14 is
preferably 0.3 to 1.5 mm and more preferably about 0.4 to 1.0 mm.
As for the size of the face insert 13, its vertical dimension is
preferably 16 to 30 mm and more preferably about 18 to 25 mm, its
horizontal dimension is preferably 50 to 150 mm and more preferably
about 70 to 100 mm, the thickness of the lower edge portion 13b is
preferably 2 to 10 mm and more preferably about 3 to 8 mm, and the
thickness of the face insert in the notched portion 13a is smaller
than that in the lower edge portion 13b by preferably 0.6 to 0.2 mm
and more preferably 0.8 to 1.4 mm. However, the size of the face
insert 13 is not limited to these specific values.
[0059] The face insert 13 is disposed in the recessed portion 12H
such that its surface opposite to the notched portion 13a becomes
the face front surface of the putter, and the lower edge portion
13b abuts against the bottom wall surface of the recessed portion
12H. As described above, the bolt 16 is inserted in each bolt
insertion hole 15 to screw it into the female screw hole 13c,
thereby fixing the face insert 13 on the head body 12. Thus, the
putter head 11 is formed.
[0060] A putter is formed by connecting a shaft to a hosel portion
11h of the thus formed putter head 11. Upon putting with this
putter (striking a ball on a green with the face surface), the
front surface side of the upper portion of the face insert 13
slightly recedes upon hitting the ball. As a result, the amount of
top spin on the ball reduces, thus easily imparting back spin to
the ball. Therefore, in a slightly rough green or a green that has
good rolling property, a distance feel can be easily adjusted by
low rolling property. That is, in general, a ball hit with a putter
moves by sliding on the green surface with no rotation or low-speed
rotation immediately after separating from the face surface of the
putter, and, after a while, rolls without sliding on the green by
friction between the ball and the green surface (the peripheral
velocity and moving velocity of the ball become equal to each
other). When a force which acts on a ball in the top spin direction
upon hitting it with a putter head reduces, or when a force acts on
a ball in the back spin direction upon hitting it with the putter
head, the distance of sliding movement with no rotation or
low-speed rotation immediately after the hitting increases. If the
green surface is rough, the influence that the green surface exerts
on the ball reduces during sliding movement with no rotation or
low-speed rotation immediately after the hitting. As a result, the
total rolling distance until the ball stops becomes nearly equal to
that in a general green. Also, in a green with good rolling
property (more specifically, a green in which lawn grass is cut
short or a green tightened by, for example, a roller), rolling of
the ball immediately after hitting it is suppressed as top spin
weakens or back spin is generated. Thus, the total rolling distance
until the ball stops becomes nearly equal to that in a general
green. From the foregoing description, the putter head according to
the present invention allows the player to easily adjust a distance
feel in a slightly rough green or a green with good rolling
property, that is, allows the ball to roll only by a distance
intended by the player.
[0061] In face inserts 13A to 13C shown in FIGS. 14 to 16,
respectively, the front surface of the notched portion 13a has an
inclination different from that of the front surface of the notched
portion 13a in the face insert 13 mentioned above. In the face
insert 13A shown in FIG. 14, the front wall surface defining the
notched portion 13a is inclined more to the front toward its lower
portion. In the face inserts 13B and 13C shown in FIGS. 15 and 16,
respectively, the front wall surface defining the notched portion
13a is inclined more to the rear toward its lower portion. Note
that in the face inserts 13, 13A, and 13B, the lower edge portion
13b of the rear surface of the face insert and the front wall
surface defining the notched portion 13a have a stepped boundary
between them, but in the face insert 13C shown in FIG. 16, the
front surface of the notched portion 13a is formed to directly
intersect with the lower edge portion 13b. Although not shown, the
front wall surface defining the notched portion may at least partly
have a curved surface.
[0062] FIG. 17 is a sectional view of the same portion as in FIG.
12 in a putter head 11A according to still another embodiment, and
FIG. 18 is a perspective view of a face insert 13 of the putter
head 11A when viewed from the rear side.
[0063] In this embodiment, the notched portion 13a is filled with a
viscoelastic material 17. Rubber, an elastomer, or a soft synthetic
resin, for example, is used as the viscoelastic material 17.
[0064] The viscoelastic material 17 has the same size as the
notched portion 13a, and the rear surface of the viscoelastic
material 17 is flush with the lower edge portion 13b of the face
insert 13, but the viscoelastic material 7 may be thinner than the
face insert 13. Also, the viscoelastic material 17 may have a
horizontal dimension and vertical dimension smaller than the face
insert 13.
[0065] Like the putter head 11A, when the notched portion 13a is
filled with the viscoelastic material 17, an impact sound and an
impact feel upon hitting a ball can be adjusted.
[0066] Although the front surface of the face insert is flat in the
above-described embodiments, a plurality of parallel elongated
grooves may be provided. The groove preferably has a width
(vertical dimension) of about 0.3 to 1.6 mm and a depth of about
0.05 to 1.1 mm.
[0067] Although the gap 14 is formed around the face insert 13 in
the above-described embodiments, a viscoelastic material 18 such as
rubber, an elastomer, or a synthetic resin may be disposed in the
gap 14, like a putter head 11B shown in FIG. 19. Also, like a
putter head 11C shown in FIG. 20, the face insert 13 may be formed
to tightly fit in the recessed portion 12H so as to generate no gap
14.
[0068] Like the putter heads 11, 11A, and 11B shown in FIGS. 11 to
19, when the gap 14 or the viscoelastic material 18 is provided
between the side surfaces 13S of the face insert 13 and the
peripheral surface 12S of the recessed portion 12H, this prevents
generation of residual stress in the face insert, thus producing an
effect of obtaining rebound characteristics of the face insert,
which comply with the design. Other arrangements in FIGS. 17 to 20
are the same as in FIG. 12, and the same reference numerals denote
the same parts.
[0069] The above-described embodiments merely give examples of the
present invention, and the present invention may be practiced in a
mode other than those shown in the accompanying drawings. For
example, the face insert may be fixed on the head body by a fixing
means such as swaging or bonding other than bolting.
Third Embodiment
[0070] This embodiment provides a putter head which imparts back
spin, that is smaller in amount than in a general putter, to a ball
upon striking the ball, to eventually facilitate creation of top
spin of the ball, and exhibits a degree of top spin, that has a
small temperature dependence.
[0071] FIGS. 21 to 24 show a putter head 21 according to this
embodiment. The putter head 21 is provided with a recessed portion
22H in the front surface (face surface) of a head body 22, and is
also provided with a groove 22G in its top surface portion. The
groove 22G is provided with female screw holes 22a into which bolts
26 (to be described later) are screwed. A face insert 23 is
disposed to engage with the recessed portion 22H and groove 22G. In
this embodiment, the head body 22 is made of a metal such as an
aluminum alloy, a titanium alloy, a copper alloy, or stainless
steel. The face insert 23 is made of a synthetic resin such as
polyester, nylon, or urethane, or a metal such as an aluminum
alloy, a copper alloy, or stainless steel. The front surface of the
face insert 23 is flush with that of the head body 22 around the
recessed portion 22H.
[0072] The face insert 23 includes a plate portion 23a which
constitutes most of the face surface of the putter head 21, and a
bracket portion 23b extending backward from the upper edge of the
plate portion 23a, and has an inverted L-shaped longitudinal
section in the front-to-back direction. The bracket portion 23b is
provided with bolt insertion holes 23c. In this embodiment, the
upper end face of the plate portion 23a is exposed to the top
surface portion of the head body 22.
[0073] The rear surface of the plate portion 23a and the bottom
wall surface of the recessed portion 22H are spaced apart from each
other, and a viscoelastic material 27 is disposed between them to
come into contact with them. Rubber, an elastomer, or a soft
synthetic resin, for example, is used as the viscoelastic material
27. The viscoelastic material 27 may be connected by bonding or
adhesion to the rear surface of the plate portion 23a. Although the
side end face and lower end face of the viscoelastic material 27
are flush with those of the plate portion 23a in a given plane,
they may recede from the given plane.
[0074] The bolt 26 is inserted in each bolt insertion hole 23c to
screw it into the female screw hole 22a, thereby fixing the face
insert 23 on the head body 22. Thus, the putter head 1 is
formed.
[0075] The recessed portion 22H and the plate portion 23a of the
face insert 23 both have an elongated, almost rectangular shape,
when viewed from the front side.
[0076] The plate portion 23a has a horizontal dimension and
vertical dimension slightly smaller than the recessed portion 22H,
so a small gap 24 is formed between the upper, lower, left, and
right side surfaces of the plate portion 23a and the peripheral
surface of the recessed portion 22H. The width of the gap 24 is
preferably 0.3 to 1.5 mm and more preferably about 0.4 to 1.0 mm.
As for the size of the plate portion 23a, its vertical dimension is
preferably 16 to 30 mm and more preferably about 18 to 25 mm, its
horizontal dimension is preferably 50 to 150 mm and more preferably
about 70 to 100 mm, and its thickness is preferably about 0.8 to 3
mm. However, the size of the face insert 3 is not limited to these
specific values.
[0077] A putter is formed by connecting a shaft to a hosel portion
21h of the thus formed putter head 21. Upon putting with this
putter (striking a ball on a green with the face surface), the
front surface side of the lower portion of the plate portion 23a of
the face insert 23 slightly recedes upon hitting the ball, thereby
facilitating production of top spin. Thus, the hit ball exhibits
good rectilinear movement characteristics. The viscoelastic
material 27 has little influence on deformation of the plate
portion 23a, so the degree of top spin has no temperature
dependence.
[0078] Like the putter head 21, when the viscoelastic material 27
is disposed on the rear surface of the plate portion 23a, an impact
sound and an impact feel upon hitting a ball can be adjusted.
[0079] Although the bottom wall surface of the recessed portion 22H
is a vertical flat surface in the above-described embodiment, a
putter head which is provided with a deep recessed portion 22h in
the bottom wall surface of the recessed portion 22H, and a
viscoelastic material 27' including, on its rear surface, a
projecting portion fitted in the deep recessed portion 22h, may be
used, like a putter head 21' shown in FIG. 25.
[0080] Although the viscoelastic material 27 or 27' is disposed on
the rear surface of the plate portion 23a in the above-described
embodiment, the viscoelastic material 27 or 27' may be omitted to
form a space portion between the rear surface of the plate portion
23a and the bottom wall surface of the recessed portion 22H, like a
putter head 21A shown in FIG. 26.
[0081] Although the gap 24 is formed around the plate portion 23a
of the face insert 23 in the above-described embodiments, a
viscoelastic material 28 such as rubber, an elastomer, or a
synthetic resin may be disposed in the gap 24, like a putter head
21B shown in FIG. 27A. Also, like a putter head 21C shown in FIG.
28A, the plate portion 23a of the face insert 23 may be formed to
tightly fit in the recessed portion 22H so as to generate no gap
24. Like putter heads 21B' and 21C' shown in FIGS. 27B and 28B,
respectively, a deep recessed portion 22h may be provided in the
recessed portion 22H, and a viscoelastic material 27' may be
disposed.
[0082] Like the putter heads shown in FIGS. 21 to 27, when the gap
24 or the viscoelastic material 28 is provided between the
peripheral surface of the face insert 23 and that of the recessed
portion 22H, this prevents generation of residual stress in the
face insert, thus producing an effect of obtaining rebound
characteristics of the face insert, which comply with the
design.
[0083] Like a face insert 23D of a putter head 21D shown in FIG.
29A, the plate portion 23a may extend to the bottom surface of the
putter head 21D. In the putter head 21D, a viscoelastic material
27D extends to the bottom surface of the putter head 21D as well.
Note that the viscoelastic material 27D need not reach the bottom
surface of the putter head 21D. Also, the viscoelastic material 27D
may be omitted.
[0084] Like a face insert 23 of a putter head 21E shown in FIG.
30A, a depending portion 23d may be provided at the rear end of the
bracket portion 23b, overlapping the rear surface of a head body
22E, and fixed on the head body 22E using a bolt 26. Note that a
bolt insertion hole 23e which receives the bolt 26 runs through the
depending portion 23d in the front-to-back direction. Like putter
heads 21D' and 21E' shown in FIGS. 29B and 30B, respectively, a
deep recessed portion 22h may be provided in the recessed portion
22H.
[0085] Although the upper end of the plate portion 23a reaches the
upper end face of the head body in either of the above-described
embodiments, an upper edge front surface 22f of a head body 22F may
hang over the plate portion 23a of a face insert 23F so that the
plate portion 23a is disposed below the upper edge front surface
22f. Other arrangements in FIGS. 31 and 32 are the same as in FIGS.
21 and 24, respectively, and the same reference numerals denote the
same parts.
[0086] Although the rear surface of the plate portion 23a is almost
vertical in either of the above-described embodiments, the rear
surface of the plate portion 23a may be inclined, like face inserts
23G and 23H shown in FIGS. 33 and 34, respectively. In the face
insert 23G shown in FIG. 33, the rear surface of the plate portion
23a is inclined more to the front toward its lower portion. In the
face insert 23H shown in FIG. 34, the rear surface of the plate
portion 23a is inclined more to the rear toward its lower portion.
Note that although not shown, the rear surface of the plate portion
23a may at least partly have a curved surface.
[0087] Although the front surface of the face insert is flat in the
above-described embodiments, a plurality of parallel elongated
grooves may be provided. The groove preferably has a width
(vertical dimension) of about 0.3 to 1.6 mm and a depth of about
0.05 to 1.1 mm.
[0088] The above-described embodiments merely give examples of the
present invention, and the present invention may be practiced in a
mode other than those shown in the accompanying drawings. For
example, the bracket portion of the face insert may be fixed on the
head body by a fixing means such as swaging or bonding other than
bolting.
[0089] Also, a plurality of face inserts including plate portions
with different thicknesses may be prepared as spares, and one of
these spares may be selected and mounted on the head body. With
this arrangement, a face insert can be selected in accordance with,
for example, the player's preferences and conditions and the
conditions of a green in a golf course, and mounted on the head
body. This makes it possible to adjust an impact feel and the
degree of top spin. Note that when the viscoelastic material is
disposed behind the plate portion, a plurality of viscoelastic
materials with different thicknesses are also prepared as spares.
Then, a viscoelastic material with an appropriate thickness is
selected from the spares, and mounted on the head body such that
the sum of the thickness of the plate portion and that of the
viscoelastic material equals the depth of the recessed portion
22H.
Fourth Embodiment
[0090] The above-described third embodiment has given another
example of the fixing structure of the face insert in the
above-described first embodiment. This fixing structure is also
applicable to the fixing structure of the face insert in the
above-described second embodiment. In this case, the face insert
includes a plate portion disposed on the face surface, and a
bracket portion which is continuous with the lower edge of the
plate portion and extend backward along the bottom surface of the
head body. In other words, this face insert is obtained by
inverting the face insert in the above-described third embodiment.
Then, the bracket portion is fixed on the bottom surface portion of
the head body, and the rear surface of the plate portion and the
head body are spaced apart from each other. Other arrangements
described in the above-described third embodiment are also
applicable as needed to the fixing structure of the face insert in
the above-described second embodiment.
[0091] While the present invention has been described with
reference to exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed exemplary embodiments.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all such modifications and
equivalent structures and functions.
[0092] This application claims the benefit of Japanese Patent
Applications No. 2010-227748, filed Oct. 7, 2010, No. 2010-251887,
filed Nov. 10, 2010, and No. 2010-282035, filed Dec. 17, 2010,
which are hereby incorporated by reference herein in their
entirety.
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