U.S. patent application number 10/931938 was filed with the patent office on 2006-03-02 for golf club shaft having a steel and graphite composition.
Invention is credited to James M. Murphy.
Application Number | 20060046867 10/931938 |
Document ID | / |
Family ID | 35944154 |
Filed Date | 2006-03-02 |
United States Patent
Application |
20060046867 |
Kind Code |
A1 |
Murphy; James M. |
March 2, 2006 |
Golf club shaft having a steel and graphite composition
Abstract
A hybrid golf club shaft composite is disclosed. The first part
of the invention comprises a metal tip core with a composite
material over the core extending the full length of the shaft. The
second part of the invention comprises a cured composite shaft
rolled and formed on a mandrel with a metallic outer shell/tube
bonded over the composite shaft proximate to the tip area.
Inventors: |
Murphy; James M.;
(Oceanside, CA) |
Correspondence
Address: |
National IP Rights Center, LLC
Suite 400
550 Township Line Road
Blue Bell
PA
19422
US
|
Family ID: |
35944154 |
Appl. No.: |
10/931938 |
Filed: |
September 1, 2004 |
Current U.S.
Class: |
473/316 ;
473/321 |
Current CPC
Class: |
A63B 60/08 20151001;
A63B 60/06 20151001; A63B 60/00 20151001; A63B 53/12 20130101; A63B
53/10 20130101; A63B 60/10 20151001 |
Class at
Publication: |
473/316 ;
473/321 |
International
Class: |
A63B 53/10 20060101
A63B053/10; A63B 53/12 20060101 A63B053/12 |
Claims
1. A hybrid golf club shaft comprising: a metal core tube extending
a portion of the way up a shaft; a shaft material overlaying the
metal core and cured to the metal core.
2. The hybrid golf shaft of claim 1 wherein the length of the metal
core has a variable length.
3. A hybrid golf club shaft composite comprising; a cored composite
shaft rolled and formed on a mandrel; and a metal outer shell/tube
bonded over the composite shaft proximate to the tip area.
4. A hybrid golf shaft comprising: a hybrid shaft core tube section
designed to be affixed to the tip end of a golf club shaft; and a
prepreg steel shaft rolled over the core and cured therewith.
Description
FIELD OF THE INVENTION
[0001] The present invention is directed to the field of golf club
shafts. In particular, the present invention is directed to a golf
club shaft that is made of a core in the shaft tip region of metal
and a full-length outer shell that is constructed of a graphite or
other composite material. Another use of the metal would be to
secondarily bond a thin-walled metal tubular tip over the graphite
shaft in the tip region.
BACKGROUND OF THE INVENTION
[0002] There has been a long felt need for improved golf club
shafts. In particular, there is a long felt need for golf club
shafts which provide the accuracy of steel with the distance
characteristics provided by graphite or other composite materials.
A metal core will reduce twisting in the tip area of the shaft. The
hybrid shaft creates an ultra low torque shaft with the power of
graphite.
[0003] A number of patents have issued to the field of golf club
shafts. Japanese Patent No. 9,266,967 discloses the surface of a
material tube for a golf club shaft which is applied by multilayer
metal plating to plate a thin metal film on the whole surface of
the shaft to reduce torsion. For this processing, the surface is
sufficiently degreased and washed with water to be activated at
first, then a copper plating of the first layer is formed. Next,
after water washing and surface activating processing, a nickel
plating of the second plating layer is formed, following that,
after sufficient water washing, a finishing plating of the third
layer is formed, and finally water washing and drying are carried
out to complete the desired golf club shaft.
[0004] U.S. Pat. No. 6,729,970 discloses a hybrid golf club shaft
set that includes a composite shaft subset including shafts formed
entirely of composite, a composite/metal shaft subset including
shafts formed of composite/metal combination shafts, and a metal
shaft subset including shafts formed entirely of metal. The
composite shaft subset preferably includes the long irons with the
lowest lofts such as the two, three, and four iron shafts. The
composite/metal shaft subset preferably includes the middle irons
with medium lofts such as the five, six, and seven iron shafts. The
metal shaft subset preferably includes the short irons with the
highest lofts such as the eight, nine, and wedge shafts.
[0005] U.S. Pat. No. 6,203,447 discloses an athletic apparatus such
as a golf shaft that includes a first tubular segment, a second
tubular segment, and a bond apparatus to couple the first and
second tubular segments. The first segment includes an inner
surface defining a passage. The second segment is a shoulder and
projection extending axially from the shoulder. The projection
defines a bonding surface and extends into the passage. The bond
apparatus is between the bonding surface and the inner surface of
the first segment. The bond apparatus includes an adhesive coupling
the first tubular segment to the second tubular segment and a
separation element engaging the inner surface of the first segment
and the bonding surface of the second segment to maintain at least
a predetermined separation distance between the inner surface and
bonding surface.
[0006] U.S. Pat. No. 5,993,328 discloses a hollow golf club shaft
including a plurality of diverging and converging substantially
frustoconical sections. The sections have respective predetermined
substantially constant wall thicknesses.
[0007] U.S. Pat. No. 5,984,804 discloses a lightweight shaft that
includes a plurality of non-metallic fibers arranged in prescribed
orientations from one end of the shaft to the other and carried by
a cured plastic material. Additional fibers are carried by the
cured plastic material and are located at a butt end of the shaft
to form a strengthening band which precludes splitting and cracking
of the shaft at the butt end. A lightweight filler element, which
is composed of a rigid foam material, is located within a portion
of an opening at a tip end of the shaft to strengthen the tip
end.
[0008] U.S. Pat. No. 5,882,268 discloses a golf club that includes
a shaft with a grip assembled on a butt end of the shaft. A club
head is mounted on a tip end of the shaft. The shaft is composed of
a non-metallic material, such as fibers in a cured plastic matrix,
and is formed with a tapered intermediate section. The section
includes two segments which taper at different taper rates. A bulge
is formed in the shaft near an inboard extremity of the tip end.
The bulge is formed with a central cylindrical section and
transition sections on opposite axial ends of the central section.
The diameter of the bulge at any cross section thereof is greater
than the diameter of the immediately adjacent portions of the
shaft. Also, the bulge is formed with an axial opening, the
diameter of which is less than the diameter of the immediately
adjacent portions of the shaft.
[0009] U.S. Pat. No. 6,280,347 discloses a golf club shaft is
provided with ring-like shaft stiffening bodies at a given location
along the shaft in order to locate the shaft flex point
appropriately for a particular individual. Each stiffening body
consists of a quantity of an epoxy and glass fibers mixture which
is molded about the shaft and sets up to a rigid condition.
[0010] U.S. Pat. No. 6,132,323 discloses an improved shaft for a
golf club and methods of manufacturing the same. A plurality of
layers of composite fiber bound within a thermoset resin are bonded
to one or more layers of composite fiber bound within a
thermoplastic resin using a high peel strength nylon epoxy
adhesive. Preferably, the layer(s) of composite fiber bound within
the thermoplastic resin comprise the outermost layer of a golf club
shaft. In one preferred form, a plurality of plies of pre-preg
composite sheet including a thermoset resin are wrapped around a
mandrel and pre-cured. Thereafter, a layer of adhesive is wrapped
over the pre-cured plies, at least one ply of pre-preg composite
sheet including a thermoplastic resin is wrapped over the adhesive,
and a cellophane or polypropylene tape is wrapped over the
outermost layer of pre-preg. Thereafter, the ply wrapped mandrel is
placed in a mold and heated to a predetermined temperature for a
time sufficient to allow curing of all of the plies comprising the
golf club shaft. In an alternative form, the layer of fiber
comprising the thermoplastic resin may be pre-cured and used as a
shell during the curing process. Bladder molding is preferred in
such embodiments.
[0011] U.S. Pat. No. 6,692,377 discloses to an improved golf club
shaft. The golf club shaft includes a shaft body made of a
composite material, such as carbon/epoxy, and a metal foil wrapped
in a spiral pattern around at least a portion of the shaft body.
The metal foil increases the torsional stiffness of the shaft and
improves its bending stiffness, thereby enabling the first and
second frequencies of a golf club employing the shaft to remain in
a desired range.
[0012] U.S. Pat. No. 4,157,181 discloses a novel structural member,
such as a golf club shaft or other tapered tubular member, having
an unusually high resistance to torsional deflection for given
desired longitudinal deflections along with high strength and a
center of gravity more favoring the tip-end is provided by a
resin-bonded graphite fiber structure in which the fiber
orientations in each layer of the multi-layer, composite structure
are varied along the length of the shaft and in desired orientation
relationships between layers to achieve the unique combination of
properties. This structural member is prepared by helically placing
fiber yarns such as graphite onto a resin-coated, tapered steel
mandrel by winding a series of high modulus graphite yarns in
series of layers and progressively varying the rotational speed of
the rings carrying the spools of the graphite fiber yarns in each
layer as the mandrel is fed at a constant speed. The continuously
varying rotational speeds of these rings and the wrapping angles to
which the yarns are applied to the mandrel result in a unique
structure achieved by optimizing the wrapping angles in each layer
at desired progressive changes in fiber orientation different in
each layer, and from layer to layer in the structure.
[0013] U.S. Pat. No. 5,505,447 discloses a golf putter having a
flexible hosel between the shaft and the blade. A rigid canopy
covers the distal end of the shaft and the proximal end of the
hosel, thereby coupling the two. The hosel may be split into two
flanges or may be a single, solid piece and is preferably made of
graphite or spring steel. When the blade strikes the golf ball, the
hosel is deformed and thereby stores energy from the stroke which
is normally lost to noise, shaft vibration and blade rebound. The
spring nature of the hosel returns the deformed hosel to its
quiescent state, thereby imparting the stored energy to the ball in
the line of the putt. The amount of deformation experienced by the
hosel is controlled by the amount of the hosel covered by the
canopy.
[0014] U.S. Patent Application No. 2002/0187850 discloses a method
for altering a graphite golf club shaft having a hollow interior
with an interior wall surface, a butt end, and a flex zone sixteen
inches from the butt end with a range one inch up and one inch down
from the measured sixteen inch point which includes placing a
section of steel tubing into the hollow interior shaft and against
the interior wall surface in the flex zone.
[0015] Canadian Patent Application No. 2,231,908 discloses a shaft
of the present invention is formed as an axially elongated member
for use in sports equipment, such as golf clubs, fishing rods or
the like. The shaft is made from composite polymers, such as a
graphite composite and includes an outer sidewall which extends
radially about an axis to define a substantially hollow or resin
filled core. At least part of the core is divided into two or more
longitudinally extending cavities by a reinforcing web or member
which spans radially separate points along the shaft sidewall. The
reinforcing member is preferably axially elongated anti extends at
least part way along the portion of the shaft. The position of the
reinforcing member is oriented in the shaft to increase the shaft
rigidity against bending in the direction of bending, load and/or
impact forces.
[0016] Heretofore, there has not been an effective system which
joins the benefits of steel and graphite in golf shafts. Such a
shaft would enable a user to achieve the power of graphite with the
control of steel.
[0017] It is an object of the present invention to provide a novel
golf club shaft which has a metal core composite and which includes
an anisotropic material such as graphite.
[0018] It is a further object of the present invention to provide a
hybrid golf shaft which contains either an outer core or an inner
core of an anisotropic material.
[0019] It is a further object of the present invention to provide a
unique hybrid golf club shaft comprising steel and graphite.
[0020] These and other objects of the present invention will become
apparent from the detailed description which follows.
SUMMARY OF THE INVENTION
[0021] In accordance with the present invention, a hybrid golf club
shaft comprising: a tapered tube metal core draft extending a
portion of the way up a shaft; and a shaft material overlaying the
tapered tube metal core and cured to the tapered tube metal core.
The hybrid golf club shaft has a tapered tube metal core with
variable length.
[0022] In a further embodiment, the invention is a hybrid golf
shaft composite comprised of a cured composite shaft rolled and
formed on a mandrel; and a tapered metal shell tube that is
secondarily bonded over the composite shaft proximate to the tip
area of the shaft.
[0023] In a yet further embodiment, the invention is a hybrid golf
shaft comprising a hybrid shaft core tube section designed to be
affixed to the tip end of a golf club shaft; and a prepreg steel
shaft rolled over the core and core-cured therewith.
BRIEF DESCRIPTION OF THE FIGURES
[0024] FIGS. 1 to 5 are a perspective view of the components of a
first embodiment of the present invention.
[0025] FIGS. 6 to 10 are a perspective view of an alternative
embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] The present invention is described with reference to the
enclosed Figures wherein the same numbers are used where
applicable. The invention comprises a golf shaft comprising and
including an anisotropic composite layer such as constructed from
graphite. The composite allows the shaft to flex more than a steel
shaft.
[0027] The graphite crystal is one of the most anisotropic (meaning
exhibiting properties with different values when measured along
axes in different directions) bodies known. Anisotropy is the
direct result of the layered structure with extremely strong
carbon-carbon bonds in the basal plane. Properties of graphite
crystals illustrating this anisotropy are shown in Table 1. Of
particular interest for the electronics cooling market is the very
high basal plane thermal conductivity (.about.2000 W/mK) achievable
in single crystal graphite. TABLE-US-00001 TABLE 1 Properties of
Graphite Crystals at Room Temperature Property Value in Basal Plane
Value Across Basal Plane Resistivity m 0.40 .about.60 Elastic
Modulus GPa 1020 36.5 Tensile Strength (est.) GPa 96 34 Thermal
Conductivity W/mK .about.2000 10 Thermal Expansion oC-1 -0.5
.times. 10-6 27 .times. 10-6
[0028] Referring to FIG. 1, the invention is directed to a hybrid
golf shaft 10. The purpose of the invention is to provide a golf
club which combines the accuracy of steel with the distance of
graphite. A metal core reduces twisting in the tip of the shaft and
creates an ultra-low torque shaft. The shaft's kick point is
governed by the graphite or composite in order to retain distance
and feel. Hence, the mid and butt portions of the shaft are
constructed from an anisotropic material such as graphite to retain
strength. The insert (core) may be either longer or shorter, as
required.
[0029] The structure of the present invention is now described. The
golf shaft manufacturing methods comprises a rolling mandrel core 1
which is stepped 12 to accept a metal core tube 14. FIG. 2
illustrates a hybrid shaft metallic core rube 14 comprising
anisotropic graphite. The metallic core can be of varying length to
meet different design parameters, and fits over the mandrel 10.
[0030] FIG. 3 illustrates the mandrel 10 with the shaft core 14 in
place. FIG. 4 illustrates a pre-preg shaft material 16. The shaft
16 is rolled over the core 14 and co-cured. FIG. 5 illustrates a
tip section view of the graphite on the outside of the metal core
showing core 14 and pre-peg shaft 16.
[0031] FIG. 6 illustrates another embodiment of the invention in
which a pre-preg shaft material 18 is rolled and cured on a mandrel
as shown in FIGS. 7 to 9. A cured composite shaft 20 is then
co-bonded. A metallic outer shell tube 22 comprising anisotropic
material is then placed on the shaft. A cured shaft with metal
shell bonded in the tip area is thus provided.
[0032] The present invention has been described with reference to
the above-discussed preferred embodiment. It is to be appreciated
that the true nature and scope of the invention is to be determined
with reference to the claims attached hereto.
* * * * *