[0001] This invention relates to a golf club. More particularly the invention is concerned
with the provision of a novel connection between the head of a golf club and the shaft.
In prior art golf clubs as shown in figure 1 a golf club 1 comprises a head 2 connected
to a shaft 3. the head 2 has a striking face 4 with a so called sweet- spot 5 which
is usually arranged to occur at the geometrical centre of area of the striking face
4 as indicated by the crossed lines. Ideally impact with a golf ball is sought to
take place at the sweet-spot 5. A problem with this prior art arrangement is that
the shaft 3 is displaced somewhat from the impact area and is fixed directly to the
head 2. As a consequence of this some of the energy of impact is dissipated within
the head thus lessening the amount of impact energy which can be transmitted up the
shaft to the player's hands so that in one sense the amount of energy available to
define "feel" is reduced.
[0002] According to the present invention there is provided a golf club having a head including
a striking face with a sweet-spot, the head comprising an outer shell member defining
a cavity, an insert located within the cavity spaced from the outer shell member and
a shaft connection fixed to the insert through the outer shell.
[0003] The present invention will now be described by way of example only and with reference
to the accompanying drawings wherein:
Figure 1 is a prior art golf club and connection.
Figure 2 is a part sectional elevation of a golf putter in accordance with the present
invention.
Figure 3 is a part elevational view looking on arrow "A" of figure 2
Figure 4 is a perspective view of an insert used in the practice of the invention.
Figure 5 is a perspective view of a putter head and shaft connection in accordance
with the present invention.
[0004] In figure 2 there is shown a golf putter 10 in accordance with the present invention.
Golf putter 10 comprises a generally T-shaped head 11 connected to a shaft 12 by means
of a hosel member 13. Hosel member 13 may be hollow. A shaft connection may comprise
the hosel member 13 or the hosel member 13 may be dispensed with and the shaft connection
may comprise a shaft 14 connected directly to the head 11 . The head 11 comprises
an outer shell member 15 which defines a cavity 16 within the head 11. An important
part of the present invention is the use of a cylindrical inner insert member 17 located
within cavity 16 of head 11. Insert member 17 is made of bronze material and defines
a rear cavity 18. The bronze material is selected to be a soft ductile material to
facilitate the transmission of shock. A sweet spot 19 of the head 11 is arranged to
be at the centre of the circular face area of insert 17 as indicated by the crossed
lines as best seen in figure 4. An aperture 20 is formed in insert 17 by drilling
and reaming to receive and ensure a proper fit with either hosel 13 or shaft 14. As
seen in figure 2 hosel member 13 stops short of the end of the aperture 20 so that
it does not contact outer shell member 15. It is believed this arrangement enhances
the transmission of impact energy to the putter shaft as feel. Cavity 18 in combination
with the remaining part of cavity 16 defines a void 21 in head 11. Void 21 is believed
to increase the resonance factor of head 11. Insert 17 is supported and fixed within
cavity 16 by means of Neoprene resilient O-rings 22, 23 fitted to semi-circular grooves
24, 25 formed around the circular periphery of insert 17. A small clearance exists
between insert 17 and a shoulder 26 formed within outer shell member 15. Also as best
seen in figure 2 the 0-rings 22,23 space the insert 17 from outer shell member 15
so that a small clearance 31 is formed which in a sense insulates insert 17 from outer
shell member 15. Stabilising or inertia weights 27 are let into the sides 28 of the
head 11 to minimise the effect of off-centre hits. A slot 29,see figure 5, assists
in aiming the striking face 30 of the putter head 11. Outer shell member 15 and hosel
member 13 are made of aircraft quality high strength aluminium and when shaft 12,14
comprises a substantially large diameter shaft the shaft will be made of carbon fibre
material. In addition to resiliently fixing insert 17 within cavity 16 the O-rings
act as seals to prevent dirt and moisture from entering void 21 through clearance
31. Shaft 14 or hosel member 13 enters the aperture 20 in insert 17 through a hole
29 drilled in outer shell member 15. As can be appreciated from figure 3 because insert
17 is insulated from outer shell member 15 by the resilient O-rings any impact on
insert 17 is transferred more or less directly to shaft 14 or hosel 13 with less impact
energy being dissipated within head 11. Consequently a golf club, for example a putter
as shown in figure 2 may have an increased "feel factor" due to the increased energy
being transmitted up the shaft 12, 14. It has been found in practice that the void
21 also enhances the feel factor. The present invention may be used with so called
standard shafts. However, the invention can be most advantageously used in a putter
with a substantially large diameter (between 25 and 45mm), thin walled, parallel shaft
to enhance the "feel factor". The present invention may be used in golf clubs other
than putters but in that case due care must be taken with the design because of the
higher forces that may be involved.
1. A golf club having a head including a striking face with a sweet spot, the head comprising
an outer shell member defining a cavity, an inner insert member located within the
cavity spaced from the outer shell member and a shaft connection fixed to the insert
through the outer shell member.
2. A golf club according to claim 1, wherein the inner insert member is resiliently supported
within the cavity.
3. A golf club according to claim 2, wherein the inner insert member is supported by
resilient O-rings.
4. A golf club according to claim 3, wherein the O-rings seal the insert within the cavity
of the outer shell member.
5. A golf club according to claim 3 or claim 4, wherein the resilient O-rings comprise
the material Neoprene.
6. A golf club according to any of the preceding claims, wherein the shaft connection
comprises a hosel member fitted to the insert.
7. A golf club according to claim 6, wherein the hosel member fits within an aperture
formed in the insert and stops short of the end of the aperture so that it does not
contact the outer shell member.
8. A golf club according to claim 6 or claim 7, wherein the hosel member is hollow.
9. A golf club according to any of claims 6 to 8, wherein the shaft connection comprises
a shaft fitted to the hosel.
10. A golf club according to claim 9, wherein the shaft member comprises a shaft of substantially
large diameter (between 25 and 45mm), thin walled, parallel shaft.
11. A golf club according to any of claims 5 to 10, wherein the outer shell member and
the hosel is made of high strength aircraft quality aluminium.
12. A golf club according to any of the preceding claims, wherein the insert defines the
sweet spot of the head.
13. A golf club according to any of the preceding claims, wherein the insert includes
a rear cavity.
14. A golf club according to claim 13, wherein the cavity in the rear of the insert and
part of the cavity in the outer shell member form a void in the head.
15. A golf club according to any of the preceding claims, the club comprising a putter.
16. A golf club according to any of the preceding claims, wherein the insert is made of
a soft ductile bronze material.