U.S. patent application number 11/954014 was filed with the patent office on 2009-06-11 for hockey stick blade having fiber-reinforced high density foam core.
Invention is credited to Isaac Garcia.
Application Number | 20090149284 11/954014 |
Document ID | / |
Family ID | 40722235 |
Filed Date | 2009-06-11 |
United States Patent
Application |
20090149284 |
Kind Code |
A1 |
Garcia; Isaac |
June 11, 2009 |
Hockey Stick Blade Having Fiber-Reinforced High Density Foam
Core
Abstract
A composite hockey stick blade including a fiber reinforced,
high-density foam polymeric core material overlaid with a plastic
wrap. The fiber reinforcement material, in the form of a plurality
of milled or long fibers, provides increased toughness and
stiffness of the high density polymeric foam core material. The
hockey stick blade may be utilized as a replacement blade for a
two-piece hockey stick, or may be a portion of a one-piece hockey
stick.
Inventors: |
Garcia; Isaac; (San Diego,
CA) |
Correspondence
Address: |
WARNER NORCROSS & JUDD LLP
900 FIFTH THIRD CENTER, 111 LYON STREET, N.W.
GRAND RAPIDS
MI
49503-2487
US
|
Family ID: |
40722235 |
Appl. No.: |
11/954014 |
Filed: |
December 11, 2007 |
Current U.S.
Class: |
473/563 |
Current CPC
Class: |
A63B 2209/00 20130101;
A63B 2102/24 20151001; A63B 2209/023 20130101; A63B 59/70 20151001;
A63B 2102/22 20151001 |
Class at
Publication: |
473/563 |
International
Class: |
A63B 59/14 20060101
A63B059/14 |
Claims
1-12. (canceled)
13. A method for forming a composite hockey stick blade having a
hosel, a heel section, and a paddle portion, the method comprising:
providing a multi-piece mold having an inner cavity defined
therewithin, said inner cavity shaped to correspond in size and
shape to the composite hockey stick blade; coupling one or more
plies of a plastic wrap along a front surface and a rear surface of
said inner cavity, said front surface corresponding to a front face
of the paddle portion and said rear surface corresponding to a rear
face of the paddle portion; coupling one or more strips of
reinforcement along a bottom surface of said inner cavity, said
bottom surface corresponding to a bottom edge of the paddle
portion; coupling a fiber reinforced high density polymeric foam
core section onto said innermost one of said one or more strips of
reinforcement between said one or more plies along said front
surface and said one or more plies on said rear surface; coupling
at least one ply of said plastic wrap onto a top surface of said
fiber reinforced high density polymeric foam core section; closing
said multi-piece mold such that said fiber reinforced high density
polymeric foam core section contacts one said plies of plastic wrap
along said front surface and said rear surface, said fiber
reinforced high density polymeric foam core section also contacting
one of said one or more strips of reinforcement along said bottom
edge and further contacting one of said at least one ply along said
top surface; applying heat and pressure within said multi-piece
mold for a period of time sufficient to cure said fiber reinforced
high density polymeric foam core section, said one or more plies of
said plastic wrap, and said one or more plies of said
reinforcement; opening said multi-piece mold; and removing the
composite hockey stick blade.
14. The method of claim 13, wherein said fiber reinforced high
density polymeric foam core section comprises a high density epoxy
foam and a plurality of chopped fiber.
15. The method of claim 14, wherein said plurality of chopped
fibers comprises a plurality of milled fibers.
16. The method of claim 14, wherein said plurality of chopped
fibers comprises a plurality of long fibers.
17. The method of claim 14, wherein said plurality of milled fibers
comprises between about 0 and 5 weight percent of said fiber
reinforced high density polymeric foam core section.
18. The method of claim 13, wherein said fiber reinforced high
density polymeric foam core section comprises a high density,
non-expanding epoxy foam and a plurality of chopped fiber.
19. The method of claim 13, wherein said fiber reinforced high
density polymeric foam core section comprises a high density
expanding foam and a plurality of chopped fiber.
20. The method of claim 13, further comprising: providing a second
cavity portion within said multi-piece mold that is open and
continuous with said inner cavity, said second cavity portion
corresponding to a hosel region of the composite hockey stick
blade; coupling one or more plies of said plastic wrap to each of
the outer surfaces of said second cavity portion; and optionally
inserting a silicone plug within said one or more plies of said
plastic wrap with said second cavity portion.
21. The method of claim 20 further comprising: coupling a foam core
section within said second cavity portion.
22-23. (canceled)
Description
TECHNICAL FIELD
[0001] The present invention relates generally to a hockey stick
blade and, more particularly to, a hockey stick blade having a
fiber reinforced high density foam core.
BACKGROUND OF THE INVENTION
[0002] Typical current hockey stick blades or replacement blades
are generally made of a core material reinforced with one or more
layers of synthetic material, such as fiberglass, carbon fiber or
graphite. Traditionally, the core of the blade has been made of
natural materials, such as wood or a wood laminate. Traditional
wood constructions, however, are expensive to manufacture due to
the cost of wood and the manufacturing processes employed. Further,
wood sticks and blades are relatively heavy and have somewhat
limited durability. Finally, due to variabilities relating to wood
construction and manufacturing techniques, wood sticks are
difficult to manufacture with consistent tolerances, and even the
same model and brand of sticks and blades may have differences in
terms of mechanical properties, such as stiffness and
curvature.
[0003] Recently, in an attempt to decrease the weight of the stick
and blade, and to improve upon the durability and mechanical
properties associated with the performance of the stick or blade,
alternative core materials, such as synthetic materials reinforced
with layers of fiber material, have been utilized. The fiber layers
are usually made of woven filament fibers, typically soaked in a
resin and glued to the surfaces of the core of the blade.
Expandable fiber braids have also been used for covering the core
of the blade. These composite sticks and blades have proven to have
improved durability versus traditional wooden sticks and blades and
have many of the mechanical attributes desired by hockey players.
Further, these composite sticks and blades have less variability in
terms of tolerances related to curvature and stiffness.
[0004] Nevertheless, these sticks and blades still have
disadvantages. For example, conventional foam core materials form
blades are formed of polymeric materials that are limited in
strength and durability by a combination of factors, including the
type and density of the polymeric material forming the foam core,
the thickness of the foam core, and the amount of curing of the
foam core during processing.
[0005] Accordingly, there is a demand for a composite blade having
improved strength and durability, and hence improved playability
characteristics, that utilizes conventional polymeric foam core
materials and conventional forming techniques. These playability
characteristics include improved response while handling and/or
shooting a puck, the prevention of puck "flutter" that may occur
when a player shoots or passes the puck, and the twisting of the
blade as a puck is passed or shot.
SUMMARY OF THE INVENTION
[0006] It is therefore an advantage of the present invention to
provide a composite blade for a hockey stick with improved response
while handling and/or shooting a puck.
[0007] It is another advantage of the present invention to provide
a composite blade for a hockey stick that assists in preventing
puck "flutter" that may occur when a player shoots or passes the
puck.
[0008] It is a related advantage of the present invention to
provide a composite blade for a hockey stick that minimizes
twisting of the blade.
[0009] It is still another advantage of the present invention to
provide a composite blade for a hockey stick that has decreased
weight without adversely affecting the performance or mechanical
characteristics of the blade.
[0010] In accordance with the above and the other advantages, the
present invention provides a composite hockey stick blade having a
high density foam core paddle coupled overlaid with, or coupled
within, a plastic wrap. In addition, reinforcing materials such as
chopped fibers are introduced to the high density foam core
material to increase the toughness and durability of the blade to
better withstand the rigors of play. The presence of the high
density foam and fiber reinforcement allows the thickness of the
plastic wrap to be decreased along the front face and rear face of
the paddle while maintaining the desired performance and mechanical
characteristics of the blade. The result is a durable, stiff, and
light blade that can be formed as a part of a hockey stick or as a
separate replacement blade for a hockey stick.
[0011] These and other features and advantages of the present
invention will become apparent from the following description of
the invention, when viewed in accordance with the accompanying
drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWING
[0012] FIG. 1 is a view of the backside face of a blade according
to one embodiment of the present invention;
[0013] FIG. 2 is a cross-sectional view of a portion the blade of
FIG. 1 in the direction of arrows 2-2; and
[0014] FIG. 3 is a cross-sectional view of a two-piece mold used to
form the blades of FIGS. 1-2 in accordance with one embodiment of
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] Referring now to the FIGS. 1-2, a hockey blade 10 is
depicted in accordance with a preferred embodiment of the present
invention. It should be understood that while the preferred blade
is intended for use in the sport of ice hockey, it can also be
utilized in other sports, including roller hockey and field hockey.
In general, the blade 10 comprises a hosel 12, a heel section 14,
and a paddle (blade portion) 16. The heel section 14 is located at
the junction of the hosel 12 and the paddle 16. The hosel 12
includes a tenon 18, or insert, adapted to be inserted into a
hollow hockey stick shaft (not shown) made of aluminum, composite
or graphite. It will be understood that the hockey stick shaft can
be made of a variety of other materials, including but not limited
to wood or wood laminate. The paddle 16 includes a front face 20
and a rear face 22 and further comprises a top edge 24, a tip
region 26 and a bottom edge 28.
[0016] The blade 10, as shown in FIG. 2, is preferably formed as a
composite structure having an inner foam core 100 overlaid with, or
sandwiched within, with a plastic wrap 101. The hosel 12 and tenon
18 are preferably formed having one or more layers of the plastic
wrap (shown as a plurality of plies 197 in FIG. 3) that are wrapped
around a hollow cavity and may include an inner foam core (shown as
199 in FIGS. 1 and 3).
[0017] The inner foam core 100 and foam core 199 (when present) are
constructed of formulations of syntactic foam or non-syntactic
polymeric foam, with syntactic foams preferred. A syntactic foam is
formed by filling a polymeric matrix material with hollow particles
called microballoons. The presence of microballoons results in
lower density, higher strength, and lower thermal expansion
coefficient core materials, which is desirable for hockey stick
blades. The microballoons used in the present invention are
typically glass microballoons or polymeric microballoons such as
polypropylene microballoons.
[0018] The polymeric matrix material used in the inner foam core
100, 199 is preferably a high-density polymeric material that cures
to form a relatively lightweight, durable, flexible, and tough
core. Preferably, the high-density polymeric matrix material is
non-expandable foaming material. The term high-density, in the
context of the present invention, is meant to describe a foam
material having a density of at least about 30 pounds per cubic
foot. The term non-expandable, in the context of the present
application, is meant to describe a polymeric material that
maintains its general shape after curing. Thus, in the present
invention, a non-expandable foam core blade will maintain its
general shape after being removed from the mold in which it is
formed, regardless of the temperature at which it is removed (i.e.
the polymeric matrix material will not expand after it is cured and
removed from the mold). One such non-expandable polymeric material
is high-density epoxy, which foams and cures to form a blade 10.
However, other polymeric materials, or blends of polymeric
materials, or different forms of the general polymeric composition,
and having one or more of these characteristics, is specifically
contemplated by the present invention.
[0019] Chopped reinforcing fibers 167, in the form of long or short
(milled) fibers, are also preferably introduced to the inner foam
core 100 and/or the foam core section 199 to provide additional
durability and/or stiffness to respective core 100 and 199. The
types of chopped reinforcing fibers 167 that may be used include
carbon fiber, graphite fiber, aramid fiber, glass fiber,
polyethylene fiber, ceramic fiber, boron fiber, quartz fiber,
polyester fiber or any other fiber that may provide the additional
desired strength to the blade 10.
[0020] In one preferred embodiment, milled carbon fiber is
introduced at a ratio of about 5% by weight of a non-expandable,
syntactic high-density epoxy foam inner foam core 100 or the foam
core section 199. In yet a more preferred embodiment, milled carbon
fiber ( 1/32'') is introduced at a load of 1.7% by weight of the
syntactic, non-expandable high density epoxy (greater than about 30
pounds per cubic foot and 0.55 SG) inner foam core 100 and/or the
foam core section 199.
[0021] The plastic wrap 101 is preferably a fiber-reinforced
prepreg material that includes one or more layers 102 comprising
one or more plies 104 of substantially continuous fibers 106
disposed in a matrix or resin based material 108.
[0022] Separate reinforcing layers 110 of the same type and
quantity as plies 104 may be placed on the top edge 24 and the
bottom edge 28 of the blade 10. It will be understood that the
blade 10 may be formed as a replacement blade, i.e. separate from
the shaft, or may alternatively be formed as a single integral unit
with the shaft. Moreover, it will be understood that the inner foam
core 100 may be reinforced with materials other than plastic wrap
101 in other ways well known to those of ordinary skill in the art
and is not meant to be limited to the preferred embodiment.
[0023] The fibers 106 employed in plies 104, 197 may be comprised
of carbon fiber, graphite fiber, aramid fiber, glass fiber,
polyethylene fiber, ceramic fiber, boron fiber, quartz fiber,
polyester fiber or any other fiber that may provide the desired
strength. In addition, fiber may also be added to the outermost ply
104, 197 to form a decorative appearance. For example, a graphite
fiber outer ply preferably constitutes the outermost ply 104 of the
paddle 16 to provide an aesthetically pleasing appearance.
[0024] The matrix or resin based material 108 is preferably
selected from a group of resin based materials, including
thermoplastic materials such as polyetheretherketone ("PEEK"),
polyphenylene sulfide ("PPS"), polyethylene ("PE"), polypropylene
urethanes ("PPU"), and nylons such as Nylon-6. The matrix or resin
based material 108 may also include or be entirely composed of a
thermosetting material, such as urethanes, epoxy, vinyl ester,
polycyanate, and polyester.
[0025] In order to avoid manufacturing expenses relating to
transferring the resin into the mold after the foam-fiber layers
are inserted into the mold, the matrix material 108 employed is
preferably pre-impregnated into the plies 104 prior to the uncured
blade assembly being inserted into the mold and the mold being
sealed. In addition, in order to avoid costs associated with the
woven sleeve materials employed in contemporary composite blade
constructs, it is preferable that the layers be comprised of one or
more plies 104 of non-woven unidirectional fibers. Suitable
materials include unidirectional carbon fiber tape pre-impregnated
with epoxy, unidirectional glass fiber tape pre-impregnated with
epoxy, and unidirectional aramid fiber tape pre-impregnated with
epoxy.
[0026] As used herein the term "ply" 104 shall mean a group of
fibers which all run in a single direction, largely parallel to one
another, and which may or may not be interwoven with or stitched to
one or more other groups of fibers each of which may be or may not
be disposed in a different direction. A "layer" 102 shall mean one
or more plies 104 that are laid down together.
[0027] The composition of the substantially continuous fibers 106,
and/or the composition of the matrix or resin based material 108,
of each individual ply 104 may be similar or varied in composition
to their respective adjacent ply 104. Moreover, the fiber
orientation of the continuous fibers 106 within an individual ply
may be the same, or varied, from the orientation of the immediately
adjacent ply 104. For example, the fiber orientation of adjacent
plies may be parallel to one another (i.e. the fibers are oriented
at a 0 degree angle relative to the next adjacent ply, forming a
0/0 orientation), perpendicular to one another (i.e. the fibers are
oriented at a 90 degree angle relative to the next ply, forming a
0/90 pattern), or may be oriented at an angle between 0 and 90
degrees (for example, at a 30 degree, or 60 degree, angle relative
to the adjacent ply). In these ways, the performance
characteristics of hockey blade, in terms of relative stiffness and
relative durability, may be varied from blade to blade, and hence
stick to stick.
[0028] Referring now to FIG. 3, one preferred method for forming
the blade 10 as described above in FIGS. 1-2 is illustrated.
[0029] First, a mold 175, corresponding to the shape of the blade
10, is formed having an inner surface 180 in the form of a front
surface 177, a rear surface 179, a top surface 181, and a bottom
surface 183 that define a cavity 185 corresponding to the outer
periphery of the front face 20, the rear face 22, the top edge 24
and the bottom edge 28. The mold 175 also includes an inner surface
187 corresponding to the outer periphery of the hosel 12, and
therein defines a second cavity portion 189 that is preferably open
and continuous with the cavity 185. The mold preferably consists of
two or more mold pieces 191, 193 that close to define the cavities
185, 189 that corresponds to the shape of the blade 10.
[0030] Next, one or more plies 104 of a plastic wrap 101, here
pre-impregnated substantially continuous fibers comprising each
respective face 22 or 24 of the blade 10, are placed into the mold
175 along the front surface 177 and the rear surface 179. As stated
above, a graphite fiber outermost ply is preferably introduced
along the front surface 177 and rear surface to provide an
aesthetically pleasing outer appearance. In addition, one or more
plies 197 of the pre-impregnated substantially continuous fibers
are placed onto the outer surface 187 of the hosel region within
the cavity region 189.
[0031] A long strip of reinforcement 110 is placed onto the bottom
surface 183 of the mold and also encloses the plies 104. The
reinforcement 110 preferably consists of one or more plies of the
pre-impregnated substantially continuous fibers of similar
composition to plies 104 and 197.
[0032] An inner foam core material 100 is then introduced within
the plies 104 within the first cavity region 185 and optionally
within the plies 197 of the second cavity region 189. Finally, a
second strip of the reinforcement 110 is draped over the inner foam
core 100 and plies 104 and will couple to the top surface 181 of
the mold 175.
[0033] Last, the plies 104 for the other face 22 or 24 of the blade
10 are added or wrapped over a foam core 100 that is generally in
the shape of the blade 10 illustrated in FIGS. 1 and 2 to create an
uncured blade assembly.
[0034] The mold 175 is closed using an automated press or tightened
down by hand using bolts (not shown). Heat is then applied to the
mold 175 sufficient to cure the inner foam core 100, the foam core
199 and the prepreg materials comprising the plies 104, 110, and
197. In the case of expanding foam materials, the curing foam
material pushes against the plies 104, 110 and 197 as the material
cures. Where non-expanding foams are utilized, the pressure exerted
by the mold itself is sufficient to ensure that the blade is shaped
in the desired manner. As one of ordinary skill will recognize, the
amount of heat and time necessary to cure the inner foam core
100,199 is dependent upon numerous factors, including but not
limited to the chemical composition of the foam core 100, 199, the
thickness of the foam core 100, 199 and the pressure exerted within
the mold.
[0035] For one preferred core material, namely a syntactic,
non-expandable epoxy foam core material having a density of about
30 pounds per cubic foot (0.55 SG), the core is cured at about 150
degrees Celsius (about 300 degrees Fahrenheit) for twenty
minutes.
[0036] When the mold cycle is complete, the blade 10 is then
removed from the mold 175. For a blade 10 having non-expanding foam
core 100,199, the blade 10 may be removed immediately. For a blade
having an expanding foam core 100, 199, the blade 10 is first
cooled below its curing and foam expansion temperature prior to
removal from the mold 175.
[0037] After removal, the blade 10 is finished to a desired outer
appearance. The finishing process may include aesthetic aspects
such as paint or polishing and also may include structural
modifications such as deburring.
[0038] The use of a high-density, fiber reinforced inner foam core
100 in the blade 10 allows the plastic wrap 101 thickness of the
paddle 16, along the front face 20 and rear face 22, to be
decreased to between about 0.045 and 0.030 inches. The reduction in
thickness of the plastic wrap 101 along the front face 20 and rear
face 22 forms a lighter blade 10 that provides better impact
capabilities, better flex loading and forgiveness without
sacrificing strength or durability, over current composite blades
having lower density foam cores and a plastic wrap thickness of
around 0.060 inches.
[0039] While particular embodiments of the invention have been
shown and described, numerous variations or alternate embodiments
will occur to those skilled in the art. Accordingly, it is intended
that the invention be limited only in terms of the appended
claims.
* * * * *