Note: Descriptions are shown in the official language in which they were submitted.
CA 02254184 1998-11-17
GOLF CLUB WITH TITANIUM HEAD AND PLASTIC HOSEL
BACKGROUND OF THE INVENTION
This invention relates generally to golf clubs and, in
particular, to a golf club commonly referred to as a "driver".
Recent developments in golf club design have included
improvements in "drivers" which are used primarily to strike a
golf ball resting on a golf tee. These improvements have
resulted in drivers with shafts made of synthetic material and
heads consisting of hollow shells made of steel, titanium and
aluminum. Examples of such improvements are disclosed in U.S.
Patent No. 5,452,890 to G. Bingman, U.S. Patent No. 5,538,246
to S. Dekura, and U.S. Patent No. 5,575,723 to S. Take et al.
The Bingman patent discloses a golf club having a cushioning
insert in a titanium head for protecting the shaft from
breakage. The Dekura patent discloses a golf club with a hosel
formed of synthetic resin for attaching the shaft to the head
which is made of magnesium or aluminum. The Take et al patent
discloses a golf club having a cushioning member made of
synthetic resin for connecting the shaft to the head.
SUMMARY OF THE INVENTION
The present invention provides a golf club comprising a
head made of a first material having a high shear modulus of
elasticity. The head includes a hollow body having a top wall,
1
CA 02254184 2001-12-27
68319-65
a bottom wall, a side wall connecting the top and bottom
walls and a front. wall. arranged for impacting a golf ba:Ll.
The head further inc:Ludes a heel end and a toe end. The
head has a bore disposed in the heel end thereof behind the
~> body front wall extending downwardly from the body top wall
toward the body bottom wall. The bore includes a top end
which. is open and a bottom end which is closed. The bore
top end is substantially flush with the top wall_ of the
body, and the bore bottom end is spaced from the bottom wall
of the body. The golf club further comprises a hosel formed
of a second material having a law shear modulus of
elasticity. The hosel includes a lower portion inserted
into the bore in the head and an upper portion extending
upwardly from the top wall of the body. The howl has a
1~~ substantially longitudinal passage extending through its
upper and lower portions. The golf club also comprises a
shaft having a tip end received in the hosel passage. The
lower portion of the hosel has an irregular out~;ide shape
and the bore in the head has a complementary irregular
2G inside shape so that the hosel may be inserted in the bore
in only one orientation. This ensures exact alignment of
the shaft relative to the head.
In the preferred embodiment of the golf club, the
first material which forms the head :is titanium, and the
25 second material which forms the hosel is plastic'. The shaft
may be made of a third material such as graphite: having a
low shear modulus of elasticity. The hosel absorbs much of
the shock resulting from the head striking a golf ball on
its front face. Since less shock is transmitted to the
30 shaft, breakage of the shaft is prevented.
2
CA 02254184 2001-12-27
68319-65
DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view of a golf club,
partially broken away, embodying the preferred Embodiment of
~~ the present invention;
Fig. la is a perspective view of the head of t=he
golf club shown in Fig. 1;
Fig. 2 is a top plan view of the golf club shown
in Fig. 1;
1C Fig. 3 is a sectional view taken along lines 3-3
in Fig. 2;
Fig. 4 is a perspective view of the hosel used in
the golf club shown in Figs.l-3;
Fig. 5 is a front. elevational view of the hosel
15 shown in Fig. 4;
Fig. 6 is a side elevat.ional view of the hosel
shown in Fig. 4;
Fig. 7 is a rear elevational view of the hosel
shown in Fig. 4; and
3
CA 02254184 1998-11-17
Fig. 8 is a sectional view taken along lines 8-8 in Fig.
5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Fig. 1, a golf club 10 according to the
present invention includes a head 12, a hosel 14 and a shaft
16. Head 12 is comprised of a hollow body 18 made of a first
material such as titanium having a high shear modulus of
elasticity. The body 18 has a top wall 20, a bottom wall 22, a
side wall 24 connecting the top and side walls 20 and 22, and
a front wall 26 arranged for impacting a golf ball. Further,
the head 12 has a heel end 12a and a toe end 12b.
A bore 28 is provided in the heel end 12a of the head 12
extending downwardly from the body top wall 20 toward the body
bottom wall 22. The bore 28 has a top end 28a which is open
and a bottom 28b which is closed. As seen in Fig. 3, the top
end 28a of the bore 28 is substantially flush with the top
wall 20 of the body 18, and the bore bottom end 28b is spaced
from the bottom wall 22 of the body 18. The bore 28 is defined
by a lateral wall 30 connected with the side wall 24 of the
head 12, and an end wall 32 connected with the lateral wall
30.
The hosel 14 is formed of a second material such as
plastic having a low shear modulus of elasticity. Hosel 14
includes an upper portion 34 that extends upwardly from the
4
CA 02254184 1998-11-17
top wall 20 of the body 18 and a lower portion 36 that is
inserted into the bore 28. The upper and lower hosel portions
34, 36 are separated by a parting line 38. The hosel 14 also
has a substantially longitudinal passage 40 extending through
its upper and lower portions 34, 36. When the golf club 10 is
assembled as shown in Fig. 3, the hosel 14 contacts the bottom
end 32 of the bore 28.
The shaft 16 is made of a third material, preferably
graphite, having a low shear modulus of elasticity. Shaft 16
has a tip end 17 received in the hosel passage 40. The shaft
tip end 17 extends completely through the hosel 14 and
contacts the bottom end 32 of the bore 28. In the preferred
embodiment of the golf club 10, the.shear modulus of
elasticity of the hosel 14 is much closer to the shear elastic
modulus of the shaft 16 than to the shear elastic modulus of
the head 12. This relationship of elastic moduli causes the
hosel 14 to absorb much of the shock resulting from the head
12 striking a golf ball on the front face 26. Therefore, less
shock is transmitted to the shaft 16 which prevents breakage
of the shaft 16 and permits the shaft 16 to have a weaker tip
end 17 which reduces cost.
Referring to Figs. 4-8, it is seen that the lower portion
36 of the hosel 14 has an irregular outside shape defined by a
generally arcuate surface 14a covering its front and sides,
and a generally flat surface 14b covering its back. The bore
CA 02254184 1998-11-17
28 in the head 12 has a complementary irregular inside shape
defined by a generally arcuate surface 28a and a generally
flat surface 28b. Therefore, the hosel 14 may be inserted into
the bore 28 in only one orientation which ensures exact
alignment of the shaft 16 relative to the head 12. In that
orientation, the generally arcuate surfaces 14a, 28a of the
hosel 14 and the bore 28 mate with each other, and the
generally flat surfaces 14b, 28b of the hosel 14 and the bore
28 also mate with each other.
Since the hosel 14 is made of softer material than the
head 12, the hosel 14 has a cushioning effect on the shaft 16.
This cushioning effect significantly reduces the amount of
vibration that is transmitted to the shaft 16 which increases
shaft life.
6
