U.S. patent application number 10/361438 was filed with the patent office on 2003-08-21 for explosion bonded laminated face inserts for golf clubs.
This patent application is currently assigned to Spalding Sports Worldwide, Inc.. Invention is credited to Mahaffey, Steven J..
Application Number | 20030157995 10/361438 |
Document ID | / |
Family ID | 27737648 |
Filed Date | 2003-08-21 |
United States Patent
Application |
20030157995 |
Kind Code |
A1 |
Mahaffey, Steven J. |
August 21, 2003 |
Explosion bonded laminated face inserts for golf clubs
Abstract
Laminated striking face inserts for golf clubs are characterized
by explosion bonding of the layers of the laminate. The outer
layers are of a substantially high strength and density material
and the center layer is of relatively lower strength and density
material. Explosion bonding results in a laminated face plate or
insert in which the yield strength of the laminate is similar to
the full strength characteristics of the materials used in the
laminate.
Inventors: |
Mahaffey, Steven J.;
(Northampton, MA) |
Correspondence
Address: |
LAW OFFICE OF LAWRENCE E LAUBSCHER, JR
1160 SPA RD
SUITE 2B
ANNAPOLIS
MD
21403
US
|
Assignee: |
Spalding Sports Worldwide,
Inc.
Chicopee
MA
|
Family ID: |
27737648 |
Appl. No.: |
10/361438 |
Filed: |
February 10, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60358450 |
Feb 19, 2002 |
|
|
|
Current U.S.
Class: |
473/342 ;
473/345; 473/350 |
Current CPC
Class: |
A63B 53/0425 20200801;
A63B 60/00 20151001; A63B 53/04 20130101; A63B 53/047 20130101;
A63B 53/0416 20200801; A63B 53/0466 20130101; A63B 2209/00
20130101 |
Class at
Publication: |
473/342 ;
473/345; 473/350 |
International
Class: |
A63B 053/04 |
Claims
What is claimed is:
1. A laminated striking face plate for a golf club head, comprising
(a) a first outer layer having an outer surface defining a striking
face of the golf club head; and (b) an inner layer having a lower
yield strength than said first outer layer; (c) said inner and
outer layers being joined by an explosion bond, whereby the yield
strength of said face plate is increased relative to the yield
strength of the layers..
2. A laminated striking face plate as defined in claim 1, and
further comprising a second outer layer opposite said first outer
layer with said inner layer being arranged therebetween, said
second outer layer having a higher strength than said inner layer
and being joined to said inner layer by said explosion bond.
3. A laminated striking face plate as defined in claim 2, and
further comprising a plurality of inner layers.
4. A laminated striking face plate as defined in claim 2, wherein
said first and second outer layers are formed of metal and have a
greater density than said inner layer.
5. A laminated striking face plate as defined in claim 4, wherein
said first and second outer layers are formed of titanium and said
inner layer is formed of aluminum.
6. A laminated striking face place as defined in claim 2, wherein
said second outer layer contains a plurality of spaced
openings.
7. A laminated face plate as defined in claim 2, wherein said plate
comprises an insert secured within a recess in a striking face area
of the golf club head.
8. A method for manufacturing a laminated striking face plate for a
golf club head, comprising the step of explosion bonding a first
outer layer to an inner layer, said outer layer having higher yield
strength than said inner layer and having an outer surface defining
a striking face of the golf club head.
9. A method as defined in claim 8, and further comprising the step
of bonding a second outer layer to said inner layer with the same
explosion which bonds said first outer layer to said inner layer,
said inner layer being arranged between said first and second outer
layers, said second outer layer having a higher yield strength than
said inner layer.
10. A method as defined in claim 9, and further comprising the step
of explosion bonding a plurality of inner layers between said first
and second outer layers.
11. A method as defined in claim 9, wherein said first and second
outer layers are formed of metal and have a greater density than
said inner layer.
12. A method as defined in claim 11, wherein said first and second
outer layers are formed of titanium and said inner layer is formed
of aluminum.
Description
[0001] This application claims the benefit of U.S. provisional
application No. 60/358,450 filed Feb. 19, 2002.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to golf club heads and more
specifically to golf club heads having inserts in the striking
face.
[0003] Golf clubs are designed primarily in separate categories of
woods, irons, and putters. The majority of golf club woods at the
present time are made of some metal or composite, while most irons
are made of varying types of metal. Woods can be constructed of
solid metal or can be constructed so as to have recesses in which a
face or insert is placed in the striking surface. While most irons
are made of metal, some also have recesses for accepting inserts
for the striking face.
[0004] It is recognized that advantages are provided by
redistributing the weight of golf clubs in both woods and irons so
that the weight around the perimeter of the head increases to
increase the moment of inertia, thereby increasing head stability,
which in turn lessens head rotation that imparts side spin on the
ball. This creates either a hook or slice (in the same manner as a
gear effect) through impact on off-center hits.
[0005] The present invention relates to laminated inserts and a
method for making the same which are configured to redistribute
part of the weight of the striking face to the perimeter of the
golf club head because the laminated inserts are lighter in weight
than metal inserts in order to increase the moment of inertia of
the head.
BRIEF DESCRIPTION OF THE PRIOR ART
[0006] Laminated inserts for golf club heads are well-known in the
patented prior art as evidenced by the Mahaffey et al. U.S. Pat.
No. 5,827,131 and the Mahaffey U.S. Pat. No. 6,074,309, both of
which are owned by the assignee of the present invention. Both
patents disclose inserts formed of outer metal layers and an inner
layer, where the outer layers are higher density and stronger than
the inner layer. The inserts are connected within a recess in the
golf club head by welding, an adhesive, crimping or other method
known in the art.
[0007] It is also known in the art to manufacture certain
components of a golf club head using explosion bonding. The
Ciasullo U.S. patent application publication No. 2002/0187854
discloses a wood type golf club head in which a sole plate and a
top plate each include an inner shell of less dense material which
is explosion bonded to the respective plates. The components are
then welded together to form the golf club head.
[0008] In laminated striking face inserts for golf club heads of
the prior art, the bonding strength of the laminate is usually
quite low, and it is generally lower than the yield strength of the
weakest material. The present invention was developed in order to
overcome this and other drawbacks of prior laminated inserts by
providing a laminated striking face plate or insert formed by
explosion bonding so that the yield strength of the laminate is
similar to the full strength characteristics of the materials used
in the laminate.
SUMMARY OF THE INVENTION
[0009] Accordingly, the present invention relates to a laminated
striking face plate or insert for a golf club head including a
first outer layer having an outer surface defining a striking face
of the club head and an inner layer having a lower strength than
the first outer layer. The inner and outer layers are joined by
explosion bonding to produce a face plate having a yield strength
similar to that of the lower strength material and a higher yield
strength than prior laminated face plates.
[0010] According to a preferred embodiment, a second outer layer is
provided for the face plate with the inner layer sandwiched between
the two outer layers. The second outer layer has a strength which
is greater than the inner layer.
[0011] The outer layers are preferably formed of a high strength
metal such as titanium and the inner layer is formed of
aluminum.
[0012] The invention also relates to a method for forming a
laminated striking face plate or insert wherein the layers are
bonded via explosion welding.
BRIEF DESCRIPTION OF THE FIGURES
[0013] Other objects and advantages of the invention will become
apparent from a study of the following specification when viewed in
light of the accompanying drawing, in which:
[0014] FIGS. 1 and 2 are sectional views of wood-type and iron-type
golf club heads, respectively, having striking face inserts
according to a first embodiment;
[0015] FIGS. 3 and 4 are sectional views of wood-type and iron-type
golf club heads, respectively, having striking face inserts
according to a second embodiment;
[0016] FIG. 5 is an exploded view of a laminated insert according
to a first preferred embodiment of the invention;
[0017] FIG. 6 is an exploded view of a laminated insert according
to a second embodiment of the invention;
[0018] FIG. 7 is an exploded view of a laminated insert according
to a third embodiment of the invention;
[0019] FIG. 8 is a sectional view through a laminated explosion
bonded striking face insert according to the preferred embodiment
of the invention of FIG. 5; and
[0020] FIG. 9 is a enlarged detail of the sectional view of FIG.
8.
DETAILED DESCRIPTION
[0021] FIG. 1 shows a metal wood 11 having a crown 13, a hosel 15,
and a sole 23, with a face structure 19 having a recess 17 therein.
In this particular configuration, the recess includes a lip
surrounding the recess and the insert 21 is configured so as to fit
within the recess and be secured therein adjacent the lip. This is
commonly referred to as an unsupported insert since the club head
does not have a complete surface backing adjacent the major portion
of the insert.
[0022] FIG. 2 shows an iron 30 having a sole 31, a top edge 33, and
a recess 35. Again, this recess has a lip against which the insert
37 is placed. This also provides an iron with an unsupported face
insert.
[0023] FIG. 3 shows a metal wood 40 having a crown 41, a sole 43,
and a recess 47 in the face, with the recess terminating in a thin
plate member 45 at the interior of the club head. Plate member 45
preferably has a thickness between 0.030 inch and 0.120 inch.
Insert 49 is secured within the recess using techniques known in
the art and abuts against plate 45.
[0024] FIG. 4 shows an iron 50 having a sole 53, an upper ridge 51,
and a cavity 55, with a recess 56 being backed by a thin plate 57.
Plate 57 is preferably of a thickness between 0.030 and 0.120 inch.
In this type of iron, insert 59 is secured within the recess and
abuts against metal layer 57.
[0025] While the inserts of the present invention are of a laminate
structure, such structure is not shown specifically in the FIGS.
1-4 for purposes of clarity.
[0026] FIG. 5 shows an insert 60 according to a preferred
embodiment of the invention. The insert is a laminate comprised of
outer layers 61 and 63 and an inner layer 65. In order to reduce
the weight at the center, the outer layers 61 and 63 are of a high
strength material such as 6-4 titanium and are of a reduced
thickness between 0.025 inch and 0.100 inch, or approximately 1.5
mm. Inner layer 65 is of a less dense material such as aluminum of
similar thickness.
[0027] Referring now to FIG. 6, another embodiment of the invention
will be described. Shown therein is a laminated insert 70
comprising a face outer layer 71, a rear outer layer 73, and a
center layer 75. A second inner or center layer 77 may also be
provided. This insert is for use in an iron-type club head without
a backing plate such as shown in FIG. 2. The layers are formed of
the same materials as set forth above in connection with the insert
shown in FIG. 5. However, the rear outer layer 73 contains at least
one perforation or through-opening 79 which may have a circular
configuration, a rectangular configuration, a square configuration,
an oval configuration, or any other suitable geometric
configuration which affords visual inspection of the center layer
75. This enables the user to confirm that the club head is in part
a laminate because of the visibility of the center layers. The
perforations may be hollow or may filled with an epoxy-type
material.
[0028] Although the embodiments of FIGS. 5 and 6 illustrate the
insert as having two outer layers, the insert can also be
manufactured with only a single outer layer as shown in FIG. 7. The
outer layer 81 comprises the striking face and the inner layer 85
is formed of a less dense material than the outer layer. This is
particularly suitable for an insert which is used in a club head
including a backing plate such as shown in FIGS. 3 and 4.
[0029] The layers of the laminated insert are joined by explosion
bonding or welding to form the finished insert. According to a
preferred embodiment, the layers are initially arranged in spaced
relation as shown in FIGS. 5, 6, and 7. In these figures, the outer
layers 61, 71 and 81, respectively, would form the striking face of
the golf club head, and the outer layers 63 and 73 would form the
rear face of the insert. An explosive is applied to the rear
surface of the rear outer layers 63, 73 and a detonator is
connected with the explosive. When the detonator is activated, the
explosive accelerates the rear layer 63 into bonding contact with
the inner or center layer 65 which is in turn accelerated into
bonding contact with the front outer layer 61, as shown by the
arrows between the layers of FIG. 5. Similarly, in the embodiment
of FIG. 6, the layer 73 is accelerated into layer 75 which is
accelerated into layer 77 which is accelerated into layer 71.
[0030] Explosive bonding provides metal to metal bonding between
the layers without generating excessive heat in the layers. In FIG.
8 is shown the explosive bonded layers 61, 63, and 65 of the
laminate of FIG. 5.
[0031] The spacing between the layers prior to explosion bonding is
a function of the materials being bonded. Typically, the distance
is from 0.5 to 4 times the thickness of the layers. When the
explosive is ignited, the detonation travels across the surface of
the outer layer 63 and the gas expansion of the explosion
accelerates the outer layer 63 toward the inner layer 65. Because
of the rapid movement of the outer layer toward the inner layer,
pressure is created at the opposing surfaces of the layers to
remove surface contaminants therefrom, resulting in a
metal-to-metal bond between the clean metal surfaces when the outer
layer collides with the inner layer. The same occurs between the
inner layer 65 and the front outer layer 61.
[0032] As shown in FIG. 9, the interfaces between the explosion
bonded layers have a wavy bond morphology. The metallurgical bond
results from the interface between the grains of the different
metal types of the layers. Although the explosion bonding process
generates heat, the heat is not transferred to the metal layers
because bonding occurs so quickly. Thus there is no melting or
diffusion of the layers. Accordingly, high yield strengths are
obtained. Typically, the yield strength of the laminate is similar
to the full strength characteristics of the materials used in the
laminate.
[0033] The following is a list of examples of further materials
which can be used for the layers of the insert:
1 MATERIAL TENSILE YIELD DENSITY 356 Aluminum 40000 27000 0.097
7075 Aluminum 83000 73000 0.101 Forging Brass 55000 20000 0.305
BE-CU 110000 90000 0.297 304 Stainless 85000 35000 0.290 431
Stainless 125000 95000 0.280 17-4 Stainless 150000 110000 0.280
99.0% Titanium 79000 63000 0.163 6-4 Titanium 135000 120000
0.160
[0034] Examples of some of the above materials for construction of
the laminate are as follows:
2 FACE LAYER CENTER LAYER BACK LAYER 17-4 Stainless 99.0% Titanium
17-4 Stainless 6-4 Titanium 7075 Aluminum 6-4 Titanium BE-CU 356
Aluminum BE-CU Forging Brass 356 Aluminum Forging Brass 431
Stainless 7075 Aluminum 17-4 Stainless 304 Stainless 356 Aluminum
7075 Aluminum 431 Stainless 7075 Aluminum 431 Stainless
[0035] While the preferred forms and embodiments of the invention
have been illustrated and described, it will be apparent to those
of ordinary skill in the art, that various changes and
modifications may be made without deviating from the inventive
concepts set forth above.
* * * * *