U.S. patent application number 09/954533 was filed with the patent office on 2002-06-20 for golf club and golf club head.
Invention is credited to Takeda, Hitoshi.
Application Number | 20020077193 09/954533 |
Document ID | / |
Family ID | 18854663 |
Filed Date | 2002-06-20 |
United States Patent
Application |
20020077193 |
Kind Code |
A1 |
Takeda, Hitoshi |
June 20, 2002 |
Golf club and golf club head
Abstract
A golf club whose balance adjustment is easily performed without
reducing the strength of a shaft. A golf club basically comprises a
head body 1 with one side; a hosel hole 4 with an opening on the
one side; and a shaft 2 fitted thereinto. The hosel hole 4
comprises a first hole 5 extending from the opening; and a second
hole 6 extending from a bottom of the first hole 5. The first hole
5 allows the shaft 2 to be fitted thereinto, while the second hole
6 allows one of weight-adjustment balance weights 7 to be provided
therein.
Inventors: |
Takeda, Hitoshi;
(Tsubame-shi, JP) |
Correspondence
Address: |
J. Rodman Steele, Jr.
Akerman, Senterfitt & Eidson, P.A.
Post Office Box 3188
West Palm Beach
FL
33402-3188
US
|
Family ID: |
18854663 |
Appl. No.: |
09/954533 |
Filed: |
September 17, 2001 |
Current U.S.
Class: |
473/305 |
Current CPC
Class: |
A63B 60/02 20151001;
A63B 53/02 20130101; A63B 53/047 20130101; A63B 2053/0491 20130101;
A63B 53/0466 20130101; A63B 53/0408 20200801; A63B 2209/00
20130101 |
Class at
Publication: |
473/305 |
International
Class: |
A63B 053/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 20, 2000 |
JP |
2000-387804 |
Claims
What is claimed is:
1. A golf club which comprising: a head body with one side, a hosel
hole with an opening on said one side of the head body; and a shaft
fitted thereinto, wherein said hosel hole comprises: a first hole
extending from said opening; and a second hole extending from a
bottom of said first hole, said first hole having said shaft fitted
thereinto, while said second hole having one of weight-adjustment
balance weights provided therein.
2. A golf club head comprising a head body with a hosel hole on one
side, wherein said hosel hole comprises: a first hole extending
from an opening of said hosel hole; and a second hole extending
from a bottom of said first hole, said first hole having a shaft
fitted thereinto, while said second hole having one of
weight-adjustment balance weights provided therein, said
weight-adjustment balance weights being prepared in order that the
difference in weight between the golf club head and a standardized
one may be within 5 g.
3. A golf club according to claim 1, further comprising a
through-hole formed through a side face of said weight-adjustment
balance weight, wherein the adjustment of weight is performed by
varying a size of a diameter of said through-hole.
4. A golf club head according to claim 2, further comprising a
through-hole formed through a side face of said weight-adjustment
balance weight, wherein the adjustment of weight is performed in
units of 5 g by varying a size of a diameter of said
through-hole.
5. A golf club according to claim 3, wherein said weight-adjustment
balance weight is of a short and columnar shape.
6. A golf club head according to claim 4, wherein said
weight-adjustment balance weight is of a short and columnar
shape.
7. A golf club according to claim 5, wherein said weight-adjustment
balance weight is made of tungsten alloy.
8. A golf club head according to claim 6, wherein said
weight-adjustment balance weight is made of tungsten alloy.
9. A golf club according to claim 5, wherein said weight-adjustment
balance weight is made of plastic.
10. A golf club head according to claim 6, wherein said
weight-adjustment balance weight is made of plastic.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a golf club and a golf club
head.
[0003] 2. Description of the Related Art
[0004] Due to the increased number of golfers, golf clubs have been
manufactured by mass production. Golf clubs have respective centers
of gravity (i.e., C. G.) determined at a stage of designing. If the
weight of a shaft and a grip is determined, then the position of
the center of gravity is determined by the weight of a golf club
head. Therefore golf clubs have respective standard weight
determined, corresponding to the respective positions of the C.G.
In mass production, however, it has actually been impossible to
manufacture golf club heads so that all of them may have the weight
in accordance with the respective standards when they are finished.
Accordingly, tolerance has been given so far to the standard weight
so that golf club heads could be manufactured within the weight
tolerance in a range of 4 g. For a head heavier than the standard
weight, the balance adjustment thereof is generally difficult. For
this reason, a head body has preliminarily been manufactured so
that it may be lighter than the standard weight, while the short
weight has been compensated for by putting a balance weight within
a shaft when they are assembled.
[0005] FIG. 4 shows one example of conventional methods for
adjusting the weight balance, in which a shaft hole 12 is formed in
a golf club head 11, and after a shaft 14 is fixed in the shaft
hole 12 with adhesive 13, metal powder 15 such as that of tungsten
of a high specific gravity is measured to exactly weigh the deficit
in weight, and then put into a cavity 14A of the shaft 14 from a
grip side, said metal powder being fixed at the lower end portion
of the shaft 14 by a plug such as a cork plug 16. Here reference
numeral 17 in FIG. 4 denotes a ferrule.
[0006] FIG. 5 shows another example of conventional methods,
wherein as the shaft 14 is bonded with the adhesive 13, a somewhat
larger quantity of the adhesive 13 is put into the shaft hole 12.
As the shaft 14 is made of a hollow pipe and the center portion
thereof is hollow, an excessive amount of the adhesive 13 is
allowed to get into the cavity 14A, so that a slender and
cylindrical lead body 18 or the like can be put into the shaft 14
from the grip side prior to the solidifying of the adhesive 13 to
thereby fix the lead body 18 while solidifying the adhesive 13.
[0007] However, there have been the following problems in these
conventional golf clubs:
[0008] According to the conventional golf clubs of which the weight
balance is adjusted by the foregoing former method, using the metal
powder 15 as the balance-adjustment material, there has been such a
problem that the position of the C.G. of the head deviates from
what was originally designed because the metal powder 15
undesirably extends up to the grip portion in the cavity 14A due to
the high void content of the metal powder as well as the high
volume-to-weight ratio thereof when the inside diameter of the
shaft 14 remains unchanged.
[0009] Moreover if the cork plug comes off, such problem arises
that clattering occurs due to the metal powder 15 moving freely in
the cavity 14A of the shaft 14.
[0010] According to the conventional golf clubs of which the weight
balance is adjusted by the foregoing latter method, the method is
advantageously simple as one has only to insert the lead body 18,
yet it has a drawback that unless rapid work is done skillfully,
the lead body 18 cannot be fixed as the solidification of the
adhesive 13 proceeds. Further, to fix the lead body 18 firmly, the
lead body 18 must be embedded into the adhesive 13 to some depth,
which in turn means that the adhesive 13 extends beyond a line A at
the upper end of the shaft hole 12 in the cavity 14A, In that case,
however, the investigation by the present inventor has revealed
that the mechanical strength of the shaft 14 is lowered by about
20-30% as a result. Although it is not necessarily clear what has
caused such lowered strength, it is presumably due to the fact that
if the adhesive 13 is solidified in a portion beyond the upper end
A of the shaft hole 12 within the cavity portion 14, the elasticity
of the shaft 14 is lowered at that portion, and thus the impact at
the time of hitting or the like is transmitted directly to the
shaft 14 without being reduced.
SUMMARY OF THE INVENTION
[0011] To eliminate the aforementioned problems, it is, therefore,
an object of the present invention to provide a golf club in which
the adjustment of the weight balance is easily performed without
reducing the strength of a shaft.
[0012] It is another object of the present invention to provide a
golf club head in which the adjustment of the weight balance is
easily performed without reducing the strength of a shaft.
[0013] To attain the above objects, there is proposed a golf club
according to a first aspect of the present invention, comprising: a
head body with one side; a hosel hole with an opening on said one
side of the head body; and a shaft fitted thereinto, wherein said
hosel hole comprises: a first hole extending from said opening; and
a second hole extending from a bottom of said first hole, said
first hole having said shaft fitted thereinto, while said second
hole having one of weight-adjustment balance weights provided
therein.
[0014] Accordingly, the adjustment of the weight balance in a golf
club can be performed simply by first inserting the
weight-adjustment balance weight into the second hole and then
fitting the shaft into first hole. Further, there can be obtained a
good position of the C.G in the golf club as the weight-adjustment
balance weight is disposed in the lowermost bottom portion of the
hosel hole. Furthermore, no clattering occurs because no powder is
used unlike conventional golf clubs. Additionally, there is no
reduction in strength of a shaft because the adhesive does not need
to be present in a portion beyond the upper end of the shaft hole
in the hollow portion of the shaft.
[0015] There is also proposed a golf club head according to another
aspect of the present invention, comprising: a head body with a
hosel hole on one side, wherein said hosel hole comprises: a first
hole extending from an opening of said hosel hole; and a second
hole extending from a bottom of said first hole, said first hole
having a shaft fitted thereinto, while said second hole having one
of weight-adjustment balance weights provided therein, said
weight-adjustment balance weights being prepared in order that the
difference in weight relative to standard weight may be within 0.5
g. Accordingly it is possible to mass-product golf club heads whose
weight is closer to the standard weight than those conventionally
produced, and to easily achieve the weight balance set in advance
to respective golf clubs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is an exploded perspective view showing a golf club
in accordance with an embodiment of the present invention.
[0017] FIG. 2 is a cross-sectional view illustrating a structure
for attachment of a shaft in said embodiment.
[0018] FIG. 3 is an exploded perspective view showing a balance
weight for adjusting weight.
[0019] FIG. 4 is a cross-sectional view showing a conventional
structure for attachment of a shaft.
[0020] FIG. 5 also is a cross-sectional view showing another
conventional structure for attachment of a shaft.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Hereunder is a description of an embodiment of a golf club
and a golf club head in accordance with the present invention with
reference to FIG. 1 through FIG. 3.
[0022] As shown in FIG. 1, a golf club of the present embodiment is
an iron type golf club, comprising a metal head body 1 that
constructs a golf club head and a shaft 2 that is a hollow pipe,
said shaft 2 being fitted in a hosel hole 4 which is formed in a
hosel portion 3 provided on one side of the head body 1.
[0023] A structure for attaching the shaft 2 is shown in FIG. 2. In
the embodiment, a distal end of the shaft 2 is 9.4 mm in diameter,
while said hosel hole 4 including a first hole 5 of a larger
diameter and a second hole 6 of a smaller diameter formed at the
lower portion of the first hole 5. The first hole 5 is formed to
have a 9.5 mm .phi. diameter that is 0.1 mm larger than that of the
distal end of the shaft 2 and to have a 29 mm depth. The second
hole 6 is formed to have a 5 mm diameter that is smaller than that
of the first hole 5 and to have a 5 mm depth.
[0024] The weight-adjustment balance weight 7 is housed in the
second hole 6. Said weight-adjustment balance weight 7 is made of a
tungsten alloy (the specific gravity: 17 to 18 g/cm3) manufactured
by sintering process, and is formed into a short and columnar
shape, of which the diameter and height are just enough to fit to
the second hole 6. As shown in FIG. 3, a through-hole 8 is formed
through the side face of said weight-adjustment balance weight 7
according to where it is necessary. By varying the size of the
diameter of the through-hole 8, a plurality of the balance weights
7 each being of the same external shape but different in weight by
0.5 g, such as 4 g, 3.5 g, 3 g, . . . 0.5 g can be prepared
beforehand. In the meantime, reference numeral 10 in FIG. 1 and
FIG. 2. denotes a ferrule.
[0025] A golf club according to the foregoing structure can be
produced in the following manner. That is:
[0026] In the first place, a head body 1 is manufactured by forging
or the like, and then the difference between the weight of the head
body 1 and standard weight is calculated so as to determine the
weight to be adjusted. Thereafter, one of the balance weights 7
whose weight is the closest to the weight thus determined is
selected so that the balance weight 7 thus selected is placed in
the second hole 6 of the hosel hole 4 to thereby adjust the weight
of the head body 1. Thereafter the adhesive 9 is applied to the
distal end of the shaft 2 and the inner surface of the first hole 5
of the hosel hole 4, and then the shaft 2 is fitted in the first
hole 5. As a result, a golf club with a correct position of the
center of gravity as well as the excellent weight balance can be
assembled. In that case, advance setting is desirable in order that
the head 1 may be finished to a little lighter weight than the
standard weight. In the case that the difference in weight between
the head body and the standardized one is smaller than 0.5 g, any
balance weight 7 does not need to be placed in the second hole 6,
or otherwise, a lighter balance weight 7 made of a material of a
low specific gravity such as plastic may be prepared beforehand to
be placed in the second hole 6.
[0027] As aforementioned, a golf club according to the above
embodiment comprises: the head body 1 having one side; the hosel
hole 4 with an opening on said one side of the head body 1; and the
shaft 2 attached thereto, wherein said hosel hole 4 comprises: the
first hole 5 extending from said opening; and the second hole 6
extending from a bottom of said first hole 5, said shaft 2 being
fitted into said first hole 5, while the weight-adjustment balance
weight 7 being placed in said second hole 6.
[0028] Accordingly, the adjustment of the weight balance in a golf
club can be performed simply by first inserting the
weight-adjustment balance weight 7 into the second hole 6 and then
fitting the shaft 2 into first hole 5. Further, good weight balance
is achieved because the position of the C.G in the golf club can be
free from substantial deviations as the weight-adjustment balance
weight 7 is disposed in a portion of the head body 1 that is in the
bottom of the hosel hole 4. Furthermore, no clattering occurs
because no powder is used unlike conventional golf clubs.
Additionally, there is no reduction in strength of a shaft because
the adhesive does not need to be present in a portion beyond the
upper end of the shaft hole in the hollow portion of the shaft
2.
[0029] Moreover, according to the head body 1 that constructs a
golf club head of the present invention, a plurality of the balance
weights 7 are prepared in order that the respective balance weights
7 may vary weight in units of 5 g, so that a tolerance of 0.5 g or
below relative to the standard weight is achieved, thereby making
it possible to mass-product golf club heads (corresponding to a
head body 1) whose weight is closer to the standard weight than
those conventionally produced. Specifically, as the
weight-adjustment of the balance weights 7 is performed by forming
the through-hole 8 in the balance weight 7 in the present
embodiment, it is possible to prepare various weights each being of
different weight but in the same external form, whereby the
dimensions of the balance weights 7 can be in accord with that of
the second hole 6 in diameter and depth so that the balance weight
7 can be fitted firmly and tightly.
[0030] Incidentally, the present invention should not be limited to
the aforementioned embodiment, but various modifications are
possible within the scope of the invention. For example, although
the second hole 6 is formed round and the balance weight 7 is
formed short and columnar in the aforementioned embodiment, the
second hole 6 may be formed square, and the balance weight 7 cubic.
Further, the first hole 5 and the distal portion of the shaft 2 may
be each threaded so that both can be engaged to each other to be
fitted. Although the first hole 5 is formed larger in diameter and
the second hole 6 smaller in the aforementioned embodiment, both
holes may be formed to define the same diameter. In that case, the
holes 5 and 6 may be discriminated from each other in a manner that
the portion in which the balance weight 7 is fitted defines the
second hole 6, while the portion into which the shaft 2 is fixedly
inserted defines the first hole 5. Moreover, although weight is
adjusted in units of 0.5 g in the aforementioned embodiment,
several balance weights with varying weight in units of 0.3 g for
example may be prepared so that finer adjustment of weight may be
possible, corresponding to the resultant smaller differences in
weight. Alternatively, it goes without saying that the present
invention is not limited to an iron type golf club, but may be
applied to a variety of golf clubs such as a metal or wooden wood
golf club that needs to be adjusted in weight.
* * * * *