U.S. patent application number 14/694921 was filed with the patent office on 2015-10-22 for multi-material golf club.
This patent application is currently assigned to ACUSHNET COMPANY. The applicant listed for this patent is ACUSHNET COMPANY. Invention is credited to Uday V. Deshmukh, Charles E. Golden, Jonathan Hebreo, Helene Hipp, Marni Ines, Daniel Stone.
Application Number | 20150297958 14/694921 |
Document ID | / |
Family ID | 49774889 |
Filed Date | 2015-10-22 |
United States Patent
Application |
20150297958 |
Kind Code |
A1 |
Hebreo; Jonathan ; et
al. |
October 22, 2015 |
MULTI-MATERIAL GOLF CLUB
Abstract
A golf club including a golf club head having improved mass
distribution characteristics. The golf club includes a golf club
head that is constructed multiple materials and includes a body
member, a mass member, and an interface that allows the mass member
to be coupled to the body member.
Inventors: |
Hebreo; Jonathan; (San
Diego, CA) ; Hipp; Helene; (San Diego, CA) ;
Ines; Marni; (San Marcos, CA) ; Deshmukh; Uday
V.; (Carlsbad, CA) ; Golden; Charles E.;
(Encinitas, CA) ; Stone; Daniel; (Long Beach,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ACUSHNET COMPANY |
Fairhaven |
MA |
US |
|
|
Assignee: |
ACUSHNET COMPANY
Fairhaven
MA
|
Family ID: |
49774889 |
Appl. No.: |
14/694921 |
Filed: |
April 23, 2015 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
13532068 |
Jun 25, 2012 |
|
|
|
14694921 |
|
|
|
|
Current U.S.
Class: |
473/350 |
Current CPC
Class: |
A63B 53/0433 20200801;
A63B 60/02 20151001; A63B 53/047 20130101; A63B 2053/0491
20130101 |
International
Class: |
A63B 53/04 20060101
A63B053/04 |
Claims
1. An iron-type golf club head, comprising: a body member including
a face defining a front ball-striking surface and a rear surface, a
perimeter weight portion, a muscle portion and a hosel, wherein the
face extends between a top line, a leading edge, a heel and a toe
of the body member, wherein the perimeter weight portion extends
rearward from the rear surface of the face and defines an upper
cavity of the body member, wherein the muscle portion is an
elongate portion of the body member extending from the heel to the
toe of the body member and rearward from the leading edge of the
face, wherein the muscle portion defines an elongate receptacle
extending from the heel to the toe of the body member, wherein the
receptacle only intersects an outermost surface of the golf club
head and is adjacent the leading edge of the face and extends
rearward from the leading edge of the face, wherein the body member
constructed of a first material that includes a base element; and
an elongate weight member including an elongate mass member and an
elongate interface is disposed in the receptacle so that an
outermost surface of the interface is flush with an outermost
surface of the muscle portion, wherein the mass member and the
interface are coupled at a bond surface, wherein the mass member
and the interface are exposed only from a lower surface of the body
member that extends rearward from the leading edge of the face,
wherein the mass member is constructed of a second material that
includes a base element, wherein the specific gravity of the second
material is greater than the specific gravity of the first
material, and wherein the interface is constructed of a third
material that is an alloy of the base element of the second
material.
2. The golf club head of claim 1, wherein the third material has a
specific gravity that is less than the specific gravity of the
second material.
3. The golf club head of claim 1, wherein the second and third
materials are different tungsten alloys.
4. The golf club head of claim 1, wherein the first and third
materials are weldable to each other, and wherein the first and
second materials are not weldable to each other.
5. The golf club head of claim 1, wherein the interface is bonded
to the body member by welding.
6. The golf club head of claim 1, wherein the interface is
constructed with a constant thickness from the outermost surface
toward the top line of the body member.
7. The golf club head of claim 1, wherein the mass member and the
interface are coupled only on a single surface.
8. The golf club head of claim 7, wherein the mass member has a
varying thickness from the interface toward the top line of the
golf club head, wherein the varying thickness includes at least one
of a heel portion and a toe portion of the mass member that has a
greater thickness than a central portion that is interposed between
the heel portion and the toe portion.
9. The golf club head of claim 1, wherein the interface defines a
width between a weight member leading edge and a weight member
trailing edge, wherein the mass member defines a width
corresponding to the direction of the width of the interface, and
wherein the width of the interface is equal to the width of the
mass member.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/532,068, filed Jun. 25, 2012, currently
pending, the contents of which are incorporated in their entireties
by reference herein.
FIELD OF THE INVENTION
[0002] This invention generally relates to golf clubs, and more
specifically to a golf club head having a multi-material
construction.
BACKGROUND OF THE INVENTION
[0003] Typical iron club heads are solid with flat hitting faces
and generally configured as either muscle back or cavity back
clubs. Traditionally, all irons were configured as muscle back
clubs, which are smooth at the back with low offset, a thin topline
and a thin sole. Cavity back irons have a hollowed out back and the
club head mass is redistributed to the sole and the perimeter of
the club head, which moves the center of gravity lower to the
ground and rearward. The weight distribution makes the iron launch
the ball higher and increases rotational moment of inertia thereby
lowering its tendency to rotate on mis-hits and enlarging the sweet
spot.
[0004] Some muscle back irons have an interior hollow section, such
that the club resembles a muscle back on the outside but the
interior hollow section alters the club's mass characteristics. One
example is U.S. Pat. No. 4,645,207 to Teramoto et al. The Teramoto
patent discloses a set of iron golf clubs in which the iron club is
cast by the lost wax method, and the back member is welded at the
back of the face member to form a hollow section between the back
and face members. As the club changes from a longer iron to a
shorter iron, the hollow section is gradually decreased to zero and
the sole width is gradually decreased.
[0005] Another example is U.S. Pat. No. 4,754,969 to Kobayashi. The
Kobayashi patent discloses a set of golf clubs wherein each
one-piece club head includes a hollow section behind the striking
face. Each of the club heads is made of a stainless steel by, for
example, a lost wax casting process. The material of each of the
face portions of the club heads is then annealed.
[0006] Another example is U.S. Pat. No. 7,126,339 to Nagai et al.,
which discloses utility golf clubs, which generally include a
hollow interior.
[0007] There remains a need in the art for an improved iron-type
golf club. In particular, there is a need for an iron-type golf
club that provides a construction that allows more concentrated
placement of discretionary mass.
SUMMARY OF THE INVENTION
[0008] The present invention is directed to iron-type golf clubs.
The inventive iron-type golf club provides a club head that
improves the ability to concentrate discretionary mass placement.
As a result, it increases ability to optimize the club head moment
of inertia and the center of gravity location.
[0009] In an embodiment, an iron-type golf club head comprises a
body member including a face defining a front ball-striking surface
and a rear surface, a perimeter weight portion, a muscle portion
and a hosel. The face extends between a top line, a leading edge, a
heel and a toe of the body member. The perimeter weight portion
extends rearward from the rear surface of the face and defines an
upper cavity of the body member. The muscle portion is an elongate
portion of the body member extending from the heel to the toe of
the body member and rearward from the leading edge of the face, and
the muscle portion defines an elongate receptacle extending from
the heel to the toe of the body member. The receptacle only
intersects an outermost surface of the golf club head and is
adjacent the leading edge of the face and extends rearward from the
leading edge of the face. The body member is constructed of a first
material that includes a base element. An elongate weight member
including an elongate mass member and an elongate interface is
disposed in the receptacle so that an outermost surface of the
interface is flush with an outermost surface of the muscle portion.
The mass member and the interface are coupled at a bond surface.
The mass member and the interface are exposed only from a lower
surface of the body member that extends rearward from the leading
edge of the face. The mass member is constructed of a second
material that includes a base element, and the specific gravity of
the second material is greater than the specific gravity of the
first material. The interface is constructed of a third material
that is an alloy of the base element of the second material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In the accompanying drawings, which form a part of the
specification and are to be read in conjunction therewith and in
which like reference numerals are used to indicate like parts in
the various views:
[0011] FIG. 1 is a rear view of an iron-type golf club head in
accordance with the present invention,
[0012] FIG. 2 is an exploded rear view of the golf club head of
FIG. 1;
[0013] FIG. 3 is a perspective rear view of weight members of the
golf club head of FIG. 1;
[0014] FIG. 4 is an exploded rear view of the weight members of
FIG. 3;
[0015] FIG. 5 is a rear view of an iron-type golf club head in
accordance with the present invention;
[0016] FIG. 6 is a perspective rear view of a weight member of the
golf club head of FIG. 5;
[0017] FIG. 7 is an exploded rear view of the weight member of FIG.
6;
[0018] FIGS. 8-11 are perspective views illustrating the steps in a
method of construction of the weight member of FIG. 3;
[0019] FIG. 12-16 are perspective views illustrating the steps in a
method of construction of the elongate weight member of FIG. 6;
[0020] FIG. 17 is a perspective rear view of weight members that
may be used in the golf club head of FIG. 1;
[0021] FIG. 18 is a cross-sectional view, taken along line 18-18,
shown in FIG. 17; and
[0022] FIG. 19 is a cross-sectional view, taken along line 19-19,
shown in FIG. 17.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] The present invention is directed to golf clubs having heads
that include multi-material construction. The inventive
construction utilizes golf club heads constructed of multiple
materials, with one of the materials interposed and forming an
interface between two others. Several embodiments of the present
invention are described below.
[0024] Other than in the operating examples, or unless otherwise
expressly specified, all of the numerical ranges, amounts, values
and percentages such as those for amounts of materials, moments of
inertias, center of gravity locations, loft and draft angles, and
others in the following portion of the specification may be read as
if prefaced by the word "about" even though the term "about" may
not expressly appear with the value, amount, or range. Accordingly,
unless indicated to the contrary, the numerical parameters set
forth in the following specification and attached claims are
approximations that may vary depending upon the desired properties
sought to be obtained by the present invention. At the very least,
and not as an attempt to limit the application of the doctrine of
equivalents to the scope of the claims, each numerical parameter
should at least be construed in light of the number of reported
significant digits and by applying ordinary rounding
techniques.
[0025] Notwithstanding that the numerical ranges and parameters
setting forth the broad scope of the invention are approximations,
the numerical values set forth in the specific examples are
reported as precisely as possible. Any numerical value, however,
inherently contains certain errors necessarily resulting from the
standard deviation found in their respective testing measurements.
Furthermore, when numerical ranges of varying scope are set forth
herein, it is contemplated that any combination of these values
inclusive of the recited values may be used.
[0026] Referring to FIGS. 1-4, a golf head 10 comprises club head
body member 12, a muscle back shell 14 and a plurality of
multi-material weight members 16. Body member 12 generally includes
a face 18, an upper perimeter weight portion 19 and a hosel 20.
Face 18 defines a front, ball-striking surface and a rear surface
22. Face 18 extends between a top line 24, a leading edge 26, a
heel portion 28 and a toe portion 30.
[0027] Perimeter weight portion 19 includes a top rail 21, a toe
rail 23, a heel rail 25, and a central rail 27. Perimeter weight
portion 19 extends rearward away from rear surface 22 of face 18
and defines an upper cavity 29. Top rail 21 extends rearward away
from an upper edge of face 18 and forms a portion of top line 24 of
club head 10. Toe rail 23 extends rearward away from a toe side of
face 18 along the perimeter of face 18 and between top rail 21 and
central rail 27. Heel rail 25 extends rearward away from a heel
side of face 18 between top rail 21 and central rail 27 and is
joined with face 18 and hosel 20.
[0028] A sole 32 of club head 10 extends between leading edge 26
and a trailing edge 34 in a fore/aft direction and between the heel
and toe of club head 10. In the present embodiment, sole 32 is
constructed by a combination of portions of body member 12, muscle
back shell 14, and weight members 16. In particular, leading edge
26 of body member 12 forms a front edge of sole 32 that generally
extends between heel portion 28 and toe portion 30. A lower surface
36 of muscle back shell 14 forms a central portion of sole 32.
Lower surfaces 38 of weight members 16 form heel and toe portions
of sole 32.
[0029] Weight members 16 are disposed at the heel and toe ends of
club head 10. Each of weight members 16 is constructed as a
multi-material component. For example, each weight member 16
includes a mass member 40 and an interface 42 that are constructed
from different materials. Mass member 40 provides the majority of
the mass of weight member 16 and is coupled to interface 42.
Preferably mass member 40 is coupled to interface 42 by a
metallurgical bond. As used herein, a metallurgical bond is a
coupling wherein two materials are in intimate contact so that they
share electrons between the two materials, there is preferably no
porosity or gaps at the interface and no intermediate bonding
material, such as brazing material or solder, is used. Some
porosity, however, may be present even with a metallurgical bond as
a result of the particular process. For example, powder metallurgy
may result in some porosity within the mated parts. Methods of
creating the metallurgical bond include cladding, diffusion
bonding, cold-rolling, co-forging and co-molding or
co-sintering.
[0030] Interface 42 provides a portion of weight member 16 that is
constructed with a shape and material that may be easily coupled to
body member 12 and muscle back shell 14. Preferably, the mass
member and the body member are constructed of materials that have
different base elements, such as a mass member with tungsten as a
base element and a body member with iron as a base element. In an
example, mass member 40 is constructed from a high specific gravity
tungsten-nickel alloy, and interface 42 is constructed from a lower
specific gravity tungsten-alloy that is capable of being welded to
a steel body member 12 and a steel muscle back shell 14.
[0031] The components of weight members 16 are preferably coupled
by a metallurgical bond. In an example, a pre-form of interface 42
is constructed by compressing the interface material, in powder
form, into a pre-form 43 that receives a pre-form 41 of mass member
40. The pre-form of mass member 40 is similarly constructed by
compressing the mass member material, in powder form, into the
desired pre-form shape. Pre-forms of interface 42 and mass member
40 are illustrated in FIG. 4 prior to their coupling. The interface
pre-form 43 defines a receptacle 45 that is shaped to receive the
mass member pre-form 41. The pre-forms are fit together to form a
combined pre-form that is then compressed and heated until the
pre-forms fuse together into weight member 16. Generally, the
pre-forms are constructed with larger dimensions than the final
dimensions of each of those parts after being fused to allow for
dimensional changes during the fusing process, i.e., the dimensions
are selected to provide for shrinkage caused by sintering powder
metallurgy parts.
[0032] Muscle back shell 14 is a thin metallic member that attaches
to body member 12. In particular, muscle back shell 14 includes a
heel 44, a toe 46 and a sole 48 that are coupled to body member 12.
Muscle back shell 14 is coupled to the lower portion of body member
12 and to central rail 27 of perimeter weight portion 19. Muscle
back shell 14 includes a heel step 50 and a toe step 52 that, when
combined with body member 12, form heel and toe receptacles for
weight members 16. The receptacles may be open to a lower cavity of
golf club head 10 or muscle back shell 14 may include walled
recesses that close one or both receptacles from the lower cavity.
In the present embodiment, the receptacles are open to the lower
cavity and weight members 16 are coupled to body member 12 and
muscle back shell 14 by coupling interface 42 to the perimeter of
the receptacle such as by welding.
[0033] As an alternative, additional material may be included in
muscle back shell 14 and/or interface 42 and the extra material may
be used as weld material. As an example, the extra material may be
incorporated by including ridges on the outer surfaces of shell 14
and/or interface 42 adjacent the boundary between the parts. The
extra material may then be heated by an energy source, such as a
laser, and melted so that it flows into the space between muscle
back shell 14 and weight member 16 and forms a weld providing a
mechanical coupling between the parts.
[0034] In another embodiment, shown in FIGS. 5-7, a golf club head
70 includes a body member 72 and a multi-material weight member 74.
Body member 72 is generally constructed as a cavity back iron that
includes an upper cavity portion and a lower muscle back portion.
Body member 72 includes a face 76, a perimeter weight portion 78, a
muscle portion 80, and a hosel 82. Face 76 defines a front,
ball-striking surface and a rear surface 77. Face 76 extends
between a top line 84, a leading edge 86, a heel 88 and a toe
90.
[0035] Perimeter weight portion 78 extends rearward away from rear
surface 77 and defines an upper cavity 79. Perimeter weight portion
78 includes a top rail 92, a toe rail 94 and a heel rail 96. Top
rail 92 extends rearward from face 76 and forms a portion of top
line 84 of club head 70. Toe rail 94 extends rearward from a toe
portion 98 of face 76 and along the perimeter of face 76. Heel rail
96 extends rearward from a heel portion 100 of face 76, generally
along the perimeter of face 76, and merges with a lower portion of
hosel 82. Toe rail 94 and heel rail 96 also extend between top line
84 and muscle portion 80.
[0036] Muscle portion 80 forms a lower portion of body member 72
and is an elongate portion of golf club head 70 that extends from
heel to toe. Preferably, muscle portion 80, face 76, perimeter
weight portion 78 and hosel 82 are constructed as a monolithic
body, such as by forging or casting a metallic material, such as a
steel or titanium alloy. Muscle portion 80 includes a receptacle
102 that extends into muscle portion 80 from a lower surface of
muscle portion 80 and is shaped and sized to receive, and to be
coupled to, weight member 74.
[0037] Weight member 74 includes an interface 104 and a mass member
106. In weight member 74, interface 104 and mass member 106 are
both elongate members and are coupled together to form weight
member 74. Interface 104 provides a portion of weight member 74
that is constructed with a shape and material that may be easily
coupled to body member 72 in receptacle 102. Interface 104 extends
between a heel end 108 and a toe end 110. In the present
embodiment, the thickness of interface 104 between an inner surface
112 and an outer surface 114 is generally constant. The width of
interface 104, between a leading edge 116 and a trailing edge 118,
may vary between heel end 108 and toe end 110. The width of
interface 104 is generally selected to match a desired width of
mass member 106. Preferably, interface 104 is constructed from a
material that is capable of being welded to a steel body member
72.
[0038] Mass member 106 provides the majority of the mass of weight
member 74 and is coupled to interface 104 by a metallurgical bond.
Mass member 106 has a varying thickness and includes heel portion
120 and toe portion 122 that have greater thickness than a central
portion 124. In an example, mass member 106 is constructed from a
high density tungsten-nickel alloy, and interface 104 is
constructed from a lower density tungsten-nickel alloy that is
capable of being welded to a steel body member 72.
[0039] In an example, a pre-form of interface 104 is constructed by
compressing the interface material, in powder form, into a
pre-form. The pre-form is generally shaped the same as the final
configuration of interface 104, but it is dimensionally larger to
allow shrinkage during steps of compression and fusing. Similarly,
a pre-form of mass member 106 is constructed by compressing the
mass member material, in powder form, into a pre-form and the
pre-form of mass member 106 is also dimensionally larger than the
final mass member 106 to provide for shrinkage during forming. In
the present embodiment, the pre-forms of interface 104 and mass
member 106 are stacked in a mold and the stacked pre-forms are
compressed and heated until they become fused together.
[0040] Golf club head body member 72 is preferably made from a
lower density material than mass member 106, and preferably is made
from a lower density material than interface 104. Preferably, body
member 72 has a density in the range of about 4 g/cm.sup.3 to about
8 g/cm.sup.3, interface 104 has a density in the range of about 4
g/cm.sup.3 to about 12 g/cm.sup.3, and mass member 106 has a
density in the range of about 12 g/cm.sup.3 to about 19 g/cm.sup.3.
Suitable materials for club head body member 72 include, but are
not limited to, aluminum, stainless steel or titanium and alloys
thereof. Suitable materials for interface 104 include, but are not
limited to materials having a base element of aluminum, iron,
copper, nickel, zinc, tin, titanium, lead, tungsten, tantalum,
gold, platinum or silver and alloys thereof. Suitable materials for
mass member include, but are not limited to, materials having a
base element of lead, tungsten, tantalum, gold, platinum,
molybdenum, hafnium, niobium or silver and alloys thereof. These
material alternatives are applicable to all of the embodiments
described herein.
[0041] Referring to FIGS. 8-11, the steps in a process of
constructing another example of weight member 16 will be described.
In a first step, a plurality of first members 140 are formed, by
forging, casting, pressing, machining, etc. into a desired shape.
In the present embodiment, first members 140 are generally shaped
as blocks having a trapezoidal cross-sectional shape. A second
member 142 is constructed to have a plurality of cavities that are
shaped to receive the first members 140. First members 140 are
constructed from the material of mass member 40 and second member
142 is constructed from the material of interface 42. Preferably,
the materials have different densities and the material of
interface 42 has properties that allow it to be easily coupled to
the material of body member 12.
[0042] The first members 140 are inserted into the second member
142 and the combination is subjected to a joining process. The
members may be rolled together, co-forged, or diffusion bonded so
that first members 140 form a metallurgical bond with second member
142. The coupling process results in a weight member pre-form 144,
as shown in FIG. 9. In the pre-form, the dimensions of both first
members 140 and second member 142 have been altered by the coupling
process, but the plurality of members are coupled so that they
combine to form a single integral unit.
[0043] In an example, tantalum may be used for the first members
140 and steel or titanium is used for the second member 142.
Tantalum is generally soft and malleable at room temperature and
has a very good affinity for titanium and steels, which makes it a
good candidate for bonding with golf club heads that are
constructed of either steel (e.g, irons) or titanium (e.g.,
metalwoods). Further, tantalum metal has a density of about 16.6
g/cc which is significantly greater than steel and titanium, which
makes it a suitable weight material. The first members may be
inserted into cavities of the second member and the combined
members may be heated and co-forged. The metal-to-metal contact and
elevated temperatures shear any oxide layer that has developed on
either component and provides a fresh metal-to-metal contact
thereby creating a good metallurgical bond. Additionally, in some
embodiments further heat treatment may increase the level of
diffusion of the forged component, for example, beta annealing
forged titanium alloys.
[0044] In another example, tantalum first members 140 are press fit
into a steel or titanium second member 142. Then the combined
members are rolled under high pressure so that the components
metallurgically bond to each other. The pieces may be heated prior
to rolling and/or as a subsequent heat treatment.
[0045] As a still further option, a weight member may be
constructed with first members 140 welded to second member 142.
Tantalum provides an advantage for weight members because its
density is high relative to titanium and it may be welded to
titanium. As a result, first members 140 constructed of tantalum
may be welded to a second member 142 constructed of titanium. Then
the second member, acting as an interface, may be welded to a
titanium club head body. By including the second member as an
interface, the manufacturing of the weight is simplified because it
is easier to manipulate and fixture the first and second members
separate from an entire golf club head body. It is also possible to
weld a tantalum weight member directly to a titanium golf club
head.
[0046] After the pre-form 144 is created, a piece is cut away from
the pre-form 144 to create a weight member blank 146. The weight
member blank 146 is a component that is constructed from a portion
of first member 140 and a portion of second member 142. In the
present embodiment, weight member blank 146 is a rectangular block
having a multi-material construction. The shape of weight member
blank 146 is altered, such as by machining, to create a weight
member 16 having a desired shape for the final assembly with body
member 12 and muscle back shell 14.
[0047] Referring now to FIGS. 12-16, the steps in another exemplary
process of constructing weight member 74 will be described. For
example, weight member 74 may be constructed using a process such
as cladding, in which two materials are metallurgically bonded
using a rolling process. For example, a tantalum alloy sheet 150
and a steel sheet 152 may be rolled together by a roller system 154
so that pressure and heat is created between the sheets and they
become metallurgically bonded, as shown in FIG. 12. The rolling
process couples the two sheets into an integrated sheet 156 in
which the different materials are bonded together without requiring
an adhesive or brazing material, shown in FIG. 13.
[0048] After the different materials are coupled, the integrated
sheet 156 may be formed so that it has an intermediate shape, as
shown in FIG. 14. After the integrated sheet 156 has been partially
formed, it is partitioned into pieces more similar to the final
size of weight member 74 so that a plurality of weight member
blanks 158 is formed. Finally, blank 158 is machined to the final
configuration of weight member 74. For example, and as shown in
FIG. 16, a central portion of blank 158 may be removed so that the
mass is more concentrated at the ends of the blank. As a result, in
the final weight member 74 the mass will be more concentrated on
heel and toe ends of weight member 74.
[0049] Another embodiment of weight members that may be included in
golf club head 10 are illustrated in FIGS. 17-19. Each of weight
members 160 is constructed as a multi-material component. For
example, each weight member 160 includes a mass member 162 and an
interface 164 that are constructed from different materials, and in
the present embodiment, interface 164 forms a shell over a majority
of the outer surface of mass member 162. Mass member 162 provides
the majority of the mass of weight member 160 and is coupled to
interface 164. Preferably mass member 162 is coupled to interface
164 by a metallurgical bond. Interface 164 provides an outer shell
portion of weight member 160 that is constructed with a material
that may be easily coupled to the golf club body member and the
muscle back shell. In an example, mass member 162 is constructed
from a high density tungsten-nickel alloy, and interface 164 is
constructed from a lower density tungsten-nickel alloy that is
capable of being welded to a steel body member and a steel muscle
back shell, such as a 10 g/cc tungsten nickel alloy.
[0050] The components of weight members 160 are preferably coupled
by a metallurgical bond. In an example, mass member 162 is
constructed by compressing the high density material, in powder
form, into a selected shape. As shown in FIGS. 18 and 19, mass
member 162 may include features that position it within a secondary
mold for the interface material. In particular, those positioning
features may include projections 166 that extend from one or more
surfaces of mass member 162. Preferably, projections 166 are
included on portions of mass member 162 that are directed to the
interior of the completed golf club head, so that if interface
material does not fully cover the projections, they will not form
any part of the outer surface of the complete golf club head.
[0051] Interface 164 may be formed in a mold that receives mass
member 162 prior to the insertion of interface material. For
example, mass member 162 may be inserted into the mold and centered
in the mold by projections 166. A powder form of the interface
material may then be introduced into the mold around mass member
162 and the combination compressed and heated, preferably in a
ceramic mold, to form interface 164 around mass member 162 and to
fuse the two materials.
[0052] As described, the components of the weight members may be
constructed independently or together. For example, each component
may be formed using powder metallurgy separately and then the two
parts combined and further compressed and heated together so that
they bond. In another example, a first component is created, such
as by casting, forging or powder metallurgy, and placed in a mold.
The material of a second component, in powder form, is placed in
the mold around a portion or all of the first component and the
combination is compressed and heated. In a still further example,
two or more materials in powder form are located in a mold relative
to each other as desired in the final weight member, and the
combined powders are compressed and heated.
[0053] While it is apparent that the illustrative embodiments of
the invention disclosed herein fulfill the objectives stated above,
it is appreciated that numerous modifications and other embodiments
may be devised by those skilled in the art. Therefore, it will be
understood that the appended claims are intended to cover all such
modifications and embodiments, which would come within the spirit
and scope of the present invention.
* * * * *