Note: Descriptions are shown in the official language in which they were submitted.
CA 02484806 2004-10-14
1
DESCRIPTION
Hockey Stick
Related Applications
This application is a continuation in part of United States Patent Application
Serial
Number 10/439,652 filed on May I5; 203 and claims priority thereto, the
contents of
which are hereby incorporated by reference.
Field of the Invention
The field of the present invention generally relates to hockey sticks
including
hockey stick configurations, manufacture and component structures and
combinations
thereof.
Background
Generally, hockey sticks are comprised of a blade portion and an elongated
shaft
portion. Traditionally, each portion was constructed of wood (e:g., solid
wood, wood
laminates) and attached together at a permanent joint. The joint generally
comprised a slot
formed by two opposing sides of the lower end section of the shaft with the
slot opening
on the forward facing surface of the shaft. As used in this application
"forward facing
surface of the shaft" means the surface of the shaft that faces generally
toward the tip of
the blade and is generally perpendicular to the longitudinal length of the
blade at the paint
of attachment. The heel of the blade comprised a recessed portion dimensioned
to be
receivable within the slot. Upon insertion of the blade into the slot, the
opposing sides of
the shaft that form the slot overlap the recessed portion of the blade at the
heel. The joint
was made permanent by application of a suitable bonding material or glue
between the
shaft and the blade. In addition, the joint was oftentimes further
strengthened by an . .
overlay of fiberglass material.
Traditional wood hockey stick constructions, however, are expensive to
manufacture due to the cost of suitable wood and the manufacturing processes
employed.
In addition, due to the wood construction, the weight may be considerable.
Moreover,
wood sticks lacked durability, often due to fractures in the blade, thus
requiring frequent
replacement. Furthermore, due to the variables relating to wood construction
and
manufacturing techniques, wood sticks were often difficult to manufacture to
consistent
CA 02484806 2004-10-14
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tolerances. For example, the curve and flex of the blade often varied even
within the same
model and brand of stick. Consequently, a player after becoming accustomed to
a
particular wood stick was often without a comfortably seamless replacement
when the
stick was no longer in a useable condition.
Notwithstanding, the "feel" of traditional wood-constructed hockey sticks was
found desirable by many players. The "feel" of a hockey stick can vary
depending on a
myriad of objective and subjective factors including the type of construction
materials
employed, the structure of the components, the dimensions of the components,
the rigidity
or bending stiffness of the shaft and/or blade, the weight and balance of the
shaft and/or
blade, the rigidity and strength of the j oint(s) connecting the shaft to the
blade, the
curvature of the blade, the sound that is made when the blade strikes the
puck, etc.
Experienced players and the public are often inclined to use hockey sticks
that have a
"feel" that is comfortable yet provides the desired performance. Moreover, the
subjective
nature inherent in this decision often results in one hockey player preferring
a certain
"feel" of a particular hockey stick while another hockey player prefers the
"feel" of
another hockey stick.
Perhaps due to the deficiencies relating to traditional wood hockey stick
constructions, contemporary hockey stick design veered away from . the
traditional
permanently attached blade co~guration toward a replaceable blade and shaft
configuration, wherein the blade portion was configured to include a
connection member,
often referred to as a "tennon", "shank" or "hose/", which generally comprised
of an
upward extension of the blade from the heel. The shafts of these contemporary
designs
generally were configured to include a four-sided tubular member having a
connection,
portion comprising a socket (e.g., the hollow at the end of the tubular shaft)
appropriately
configured or otherwise dimensioned so that it may slidably and snugly receive
the
connection member of the blade. Hence, the resulting joint generally comprised
a four-
plane lap joint. In order to facilitate the detachable connection between the
blade and the
shaft and to further strengthen the integrity of the joint, a suitable bonding
material or glue
is typically employed. Notable in these contemporary replaceable blade and
shaft
configurations is that the point of attachment between the blade and the shaft
is
substantially elevated relative to the heel attachment employed in traditional
wood type
constructions.
Although over the years, metallic materials such as aluminum were employed to
form tubular shafts adapted to being joined to replaceable blades in the
manner described
above; in more recent years the hockey stick industry has tended to make more
and more
CA 02484806 2004-10-14
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hockey stick shafts from composite materials. Such shafts, for example, have
been
manufactured via pulltrusion or by wrapping layers of composite fibers over a
mandrel
and then curing so that the fibers reside in a hardened resin matrix.
Although, composite
hockey stick shafts are much appreciated by players for their performance
attributes,
S applicants have found that they tend to transmit undesirable vibration more
efficiently to
the player's hands than did traditional wood constructed hockey sticks.
Contemporary replaceable blades, of the type discussed above, are constructed
of
various materials including wood, wood laminates, wood laminate overlain with
fiberglass; and what is often referred to in the industry as "composite"
constructions. Such
composite blade constructions employ what is generally referred to as a
structural
sandwich construction, which comprises a low-density rigid core faced on
generally
opposed front and back facing surfaces with a thin, high strength, skin or
facing. The skin
or facing is typically comprised of plies of woven and substantially
continuous fibers, such
as carbon, glass, graphite, or KevlarTM disposed within a haxdened matrix
resin material.
1 S Of particular importance in this type of construction is that the core is
strongly or firmly
attached to the facings and is formed of a material composition that, when so
attached,
rigidly holds and separates the opposing faces. The improvement in strength
and stiffness,
relative to the weight of the structure, that is achievable by virtue of such
structural
sandwich constructions has found wide appeal in the industry and is widely
employed by
hockey stick blade manufacturers.
Contemporary composite blades are typically manufactured by employment of a
resin transfer molding (RT1V~ process, which generally involves the following
steps. First,
a plurality of inner core elements composed of compressed foam, such as those
made of
polyurethane, are individually and together inserted into one or more woven-
fiber sleeves
2S to form an uncured blade assembly. The uncured blade assembly, including
the hosel or
connection member, is then inserted into a mold having the desired exterior
shape of the
blade. Afterthe mold is sealed, a suitable matrix material or resin is
injected into the mold
to.impregnate the woven-fiber sleeves. The blade assembly is then cured for a
requisite
time and temperature, removed from the mold, and finished. The curing of the
resin
serves to encapsulate the fibers within a rigid surface layer and hence
facilitates the
transfer of load among the fibers, thereby improving the strength of the
surface layer. In
addition, the curing process serves to attach the rigid foam core to the
opposing faces of
the blade to create -- at least initially -- the rigid structural sandwich
construction.
Experience has shown that considerable manufacturing costs are expended on the
3S woven-fiber sleeve materials themselves, and in impregnating those fiber
sleeves with
CA 02484806 2004-10-14
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resin while the uncured blade assembly is in the mold. Moreover, the process
of managing
resin flow to impregnate the various fiber sleeves, has been found to,
represent a potential
source of manufacturing inconsistency. In addition, as was the case with
composite shaft
constructs, such composite blade constructs tend to transmit undesirable
vibrations to the
player's hands, especially when coupled to a composite shaft. In this regard,
commonly
owned U.S. patent application serial number Serial 10/439,552 filed on May 15,
2003,
hereby incorporated by reference; teaches a hockey stick construction
comprising a
composite blade construct having one or more core elements formed of a
resilient
elastomer material (e.g., rubber) which may serve to dampen vibration, while
also
providing desirable performance attributes.
Composite shafts and blades, nonetheless, are thought to have certain
advantages
over wood shafts and blade. For example, composite blades and shafts may be
more
readily manufactured to consistent tolerances and are generally more durable
than their
wood counterparts. In addition, such composite constructs are capable of
providing
improved strength and hence may be made lighter: .
Notwithstanding, such constructions nevertheless also have been found by
applicanfs to produce a °'feel" and/or performance attributes (e.g.,
vibration, sound, flex)
that are unappealing to same players. Even players that choose to play with
composite
hockey sticks continually seek out alternative sticks having improved feel or
performance.
Moreover; despite the advent of contemporary composite hockey stick
constructions and
two-piece replaceable blade-shaft configurations, traditional wood-constructed
hockey
sticks are still preferred by many players notwithstanding the drawbacks noted
above. In
an on going effort to improve the state of the technology, applicants disclose
unique
composite hockey stick configurations and constructions that may overcome one
or more
of these deficiencies.
Summary of Invention
The present invention relates to hockey sticks, their manufacture,
configuration
and component structures. Various aspects are set forth below.
In one aspect, a hockey stick comprises a tubular hollow rectangular shaft
having
an outer layer and inner layer fanned of composite molded around an elastomer
middle
layer. The elastomer middle layer may be positioned any where along the
longitudinal
length of the shaft, however, it is contemplated that the elastomer layer be
configured
reside nearer the blade of the hockey stick within preferred positions
described herein.
CA 02484806 2004-10-14
Similarly, although it contemplated that the elastomer middle layer form at
least a portion
of each of the four walls that comprise the rectangular shaft, the middle
elastomer layer
may form any one of the four walls or all of the four walls or any combination
of one or
more of the four walls.
5 In another aspect, a method for manufacturing a composite hockey stick blade
is
disclosed comprising (a) providing a cured tubular shaft, such as the one
previously set
forth above, (b) providing an un-cured composite blade comprising one or more
core
elements wrapped with one or plies of fibers dimensioned to receive the lower
portion of
the hockey stick shaft, (c) inserting the cured shaft into the un-cured hockey
stick blade,
and (d) curing the composite blade around the cured hockey stick shaft.
Additional implementations, features, variations, and advantageous of the
invention will be set forth in the description that follows, and will be
further evident from
the illustrations set forth in the accompanying drawings.
Description of. the Figures
The accompanying drawings illustrate presently contemplated embodiments and
constructions of the invention and, together with the description, serve to
explain various
principles of the invention.
FIG.1 is a diagram illustrating a representative hockey stick configuration.
FIG. 2 is a rear view of a lower portion of the hockey stick illustrated in
FIG. 1
FIG. 3 is a back face view of the hockey stick blade illustrated in FIG. 1
detached
from the hockey stick shaft.
FIG. 4 is a rear view illustration taken along line 4-4 of the hockey stick
blade
illustrated in FIG. 3.
FIG. 5 is a top view illustration taken along line 5-5 of the hockey stick
blade
illustrated in FIG. 3.
FIG. 6 is a front side view of the hockey stick shaft illustrated in FIG. 1
detached
from the blade.
FIG. 7 is an enlarged partial rear view of the hockey stick shaft illustrated
in
Fig. 6.
CA 02484806 2004-10-14
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FIG. 8 is an enlarged partial front view of the hockey stick shaft illustrated
in
FIG. 6.
FIG. 9 is an enlarged bottom end view of the hockey stick shaft illustrated in
FIG. 6
FIG. 10 is a cross-sectional view of the hockey stick shaft illustrated in
Fig. 6
taken along line I O-10:
FIG. 11 is an enlarged perspective view of the cross-section illustrated in
FIG. 11,
showing the composite structure of lay-up of the shaft at line 10-I0, with
successive
layers serially exposed.
FIG. 12 is a cross-sectional view of the hockey stick shaft illustrated in
FIG. 6
taken along line 11-11.
FIG. 13 is an enlarged perspective view of the cross-section illustrated in
FIG. 11,
showing the composite structure of a preferred lay-up of the shaft at Line I1-
11, with
successive layers serially exposed.
FIG. 14 is a representative cross-sectional view taken along line 14-14 of
FIG. 3
illustrating the internal construction of the detached hockey stick blade at
the mid-region.
FIG. 15 is a representative cross-sectional view taken along line 15-15 of
FIG. 3
illustrating the internal construction of the hockey stick blade at the heel
region.
FIG.16A-C are flow charts detailing preferred steps for manufacturing the
hockey
stick illustrated in FIGS 1-15 and the component elements thereof.
FIG. 17 is a diagram of the spacer element being removed from the pre-cured
hockey stick blade illustrated in FIG. 3.
FIG. 18 is a diagram of the cured hockey stick shaft being inserted into the
pre-
cured hockey stick blade illustrated in FIG. 3.
FIG. 19 is a diagram of the uncured hockey stick blade arid the cured hockey
stick
shaft assembled in the open mold prior to curing.
FIG. 20 is a diagram of the uncured hockey stick blade and the cured hockey
stick
shaft assembled in the closed mold prior to curing.
CA 02484806 2004-10-14
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FIG. 21 is a front side view diagram of the hockey stick illustrated in FIG. 1
illustrating the length of the hockey stick (L-HS) and the length of the
hockey stick shaft
(L-S) and longitudinal distances (Ll and L2) for placement of elastomer layer
in the shaft.
Detailed Description of the Preferred Embodiments
The preferred embodiments will now be described with reference to the
drawings.
To facilitate description, any reference numeral designating an element in one
figure will
designate the same element if used in any other figure. The following
description of the
preferred embodiments is only exemplary. The present inventions) is not
limited to these
embodiments, but may be realized by other implementations. Furthermore, in
describing
preferred embodiments, specific terminology is resorted to for the sake of
clarity.
However, the invention is not intended to be limited to the specific terms so
selected, and
it is to be understood that each specific term includes all equivalents.
FIGS. 1-21 are diagrams illustrating the configuration, structure,
construction, and
manufacture of a representative hockey stick 10 and components thereof.
Generally FIGs.
1 and 2 illustrate the representative hockey stick 10 comprising a shaft 20
and the blade 30
joined to one another; FIGs. 3-5 illustrate the external configuration of the
blade 30
detached from the shaft 20; FIGs. 14-15 illustrate the internal configuration
and structure
of the blade 30; FIGs. 6-9 illustrate the external configuration of the shaft
20 detached
from the blade 30; FIGS. 10-13 illustrate the internal configuration and
structure of the
shaft 20, FIGS. 16a-I6c are flow charts detailing preferred steps for
manufacturing the
representative hockey stick 10; FIGS. 17-20 are diagrams illustrating various
aspects of the
manufacturing process set forth in Figs. 16a -16c and also further illustrate
the structure
and construction of the shaft 20 and blade 30, and lastly FIG. 21 is a diagram
employed in
conjunction with describing presently preferred locations of the elastomer
middle layer
(described in more detail below) along the longitudinal length of the shaft 20
of the
representative hockey stick 10. Each of the figures is further described in
detail below in
the foregoing order.
FIGs. 1 and 2 are diagrams illustrating a representative hockey stick 10
configuration comprising a blade 30 and a shaft 20 joined thereto. Externally,
the blade 30
comprises a lower section 70, an upper section 80, a front face wall 90, a
back face wall
100, a bottom edge 110, a top edge 120, a tip section 130, and a heel section
140, which
generally resides behind the tip section 130 of the blade 30 between the plane
defined by
the top edge 120 and the plane defined by the bottom edge 110 of the blade 30.
The heel
section 140 of the blade 30 includes a slot I45 that extends internally
between the front
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8
face wall 90 and back face wall 100 of the blade 30 and tapers or narrows as
it extends
from between the top edge 120 toward the bottom edge 110 of the blade 30 (best
illustrated in FIG. 5). The internal construction of the blade 30 is described
in more detail
in subsequent portions of this description in relation to FIGS. .14 and 15 and
the
manufacturing process described in relation to FIGs. I6a-16c and 17-20.
The shaft 20 comprises an upper section 40, a mid-section S0, and a lower
section
60, which is adapted to being interposed or joined within the slot 145 located
in the heel
section I40 of the blade 30 between the front face wall 90 and back face wall
100 of the
blade 30. In the preferred embodiment, illustrated in the drawings, the shaft
20 is
generally rectangular in cross-section with two wide opposed walls 150 and 160
and two
narrow opposed walls 170 and I80. Narrow wall 170 includes a forward-facing
surface
190 and narrow wall 180 includes a rearward-facing surface 200. The forwaxd-
facing
surface i90 faces generally toward the tip section 130 of the blade 30 and is
generally
perpendicular to the longitudinal length of the blade 30 (i.e., the length
between the heel
section 140 and the tip section 130). The rearward-facing surface 200 faces
generally
away from the tip section 130 of the :blade 30 and is also generally
perpendicular to the
longitudinal length of the blade 30. Wide wall 150 includes a front-facing
surface 210 and
wide wall 160 includes a back-facing surface 220. V~hen the shaft 20 is
attached to the
blade 30 as illustrated in FIGS. 1 and 2, the front-facing surface 210 faces
generally in the
same direction as the front face wall 90 of the blade 30 and the back-facing
surface 220
faces generally in the same direction as the back face wall 100 of the blade
30.
In the preferred embodiment; the shaft 20 includes a tapered section 330 (best
illustrated in Figs. 2, 7 and 8) having a reduced shaft width. The "shaft
width" is defined
for the purposes of this application as the dimension between the front and
back facing
surfaces 210 and 220. The tapered section 330 is dimensioned so that, when
the. shaft 20
is assembled to the blade 30 prior to curing of the blade 30, the portions of
the front and
back facing surfaces 210, 220 of the shaft 20 configured to being interposed
within slot
145 are dimensioned to fit within the slot 145 of the blade 30. The adjacent,
more
upwardly positioned portions of the front and back facing surfaces 210, 220 of
the shaft 20
are dimensioned so that they are flush with the adjacent portions of the front
and back face
walls 90 and 100 of the blade 30 residing there below.
Hence, the heel section 140 of the blade 30 includes an open-ended slot 145
that is
dimensioned to receive the lower portion of the tapered section 330 of the
shaft 20 having
a reduced width. Corresponding and opposed shoulders 280 and 290 in the shaft
20 and
blade 30 configured to reside at the transition there between facilitate the
transition
CA 02484806 2004-10-14
9
between the shaft 20 and the blade 30. Hence, when the shaft 20 is inserted
into the slot
145 of the blade 30, shoulders 280 and 290 are configured to be in opposed
alignment so
that they may abut with one another.
FIGS. 3-5 further illustrate the external configuration of the blade 30,
including the
slot 145, the front and back facing walls 90 and l00 .of the blade 30 that
form the slot 145
and the shoulder 290 of the blade 30; which is configured to generally abut
with the
shoulder 280 of the shaft 20. FIGS. 6-9, on the other hand further illustrate
the external
configuration of the shaft 20. Notably, in the representative implementation
of the hockey
stick 10, the shaft 20 is formed as a hollow tubular structure that is defined
by opposed
wide walls 150 and 160 and opposed narrow walls 170 and 180. The hollow 230 of
the
shaft 20 is configured, in the representative implementation, to extend
generally the full
longitudinal length of the shaft 20 -- from the upper section 40 to the lower
section 60,
which is tapered as it extends to its conclusion. The taper in the lower
section is
accomplished by reducing the width of the shaft 20 between the opposed wide
walls 150
1 S and 160 or in other words by reducing the width of opposing narrow walls
I70 and I80.
Notably, the width of the opposing wide walls 150 and 160 of the shaft are, in
the
representative implementation, generally uniform in dimension as the shaft
extends from
the upper section 40 toward the lower section 60. However, it is contemplated
that the
width of wide walls 150 andlor 160 may be varied at any given region.
FIGS. 10-13 illustrate a presently preferred shaft 20 structure. As previously
noted,
the shaft 20 is generally rectangular hollow tubular structure defined by
opposing side
walls 150 and 160 and opposing narrow walls 170 and 180. Generally the shaft
20
comprises an inner layer 410, an outer layer 430, and a middle elastomer layer
420. The
inner and outer layers 410 and 430 are molded around the middle elastomer
layer 420. As
best illustrated in FIGS. 10-13, the inner layer 410 is preferably constructed
to have a
greater cross-sectional thickness than the outer layer 430. A preferred
construction of the
shaft 20 comprises an inner and outer layers 410 and 430, each of which
comprising a
plurality of plies of parallel fibers or,filaments oriented in one or more
defined directions
relative to the longitudinal length of the shaft 20 and disposed in a hardened
resin matrix.
As used herein, the term "ply" shall mean a group of fibers largely parallel
to one another
and running in a single direction, and which may or may not be interwoven with
or
stitched to one or more other groups of fibers, of which each group may or may
not be
oriented in a different direction. Hence a ply may comprise un-directional
fibers all
running in a single direction, groups of woven or weaved fibers, with one
group of fibers
running in a first direction parallel with one another and another group of
fibers woven or
CA 02484806 2004-10-14
s
weaved with the first running in a second direction parallel with one another.
Unless
otherwise defined, a '°layer" shall mean one or more plies that are
laid down together or
over one another to form a definable wall structure.
An exemplary hockey stick shaft lay-up for the inner and outer layers 410 and
430
5 are set forth in the tables below:
Table: Inner Layer Lay-Up
Fiber Orientation Fiber Number of Plies
+ 45 Carbon 7
- 45 Carbon 7
0 Carbon ~ 4
Interposed between
consecutive +/-
45 Iies
Table: Outer Layer Lay-Up
Fiber Orientation Fiber Number of Plies
(From Inner most
ply to
Outer most I
0 Carbon 1
+ 45 Carbon 1
- 45 Carbon 1
0/90 Woven Carbon 1
0/90 Woven aramid 1
10 Hence in a preferred construction of the shaft 20, the inner layer 410
comprises
eighteen (18) plies of parallel fibers; whereas the outer layer 430 comprises
only five (5)
plies of parallel fibers. Hence the outer layer 430 is on the order of
approximately 1/4 to
1/3 the thickness of the inner layer 410 or in other words the inner layer 410
is three to
CA 02484806 2004-10-14
a
11
four times thicker than the outer layer 430. Furthermore, it is noted that the
outer most ply
of the outer layer 430 is woven.
Although carbon and aramid (such as Kevlar~ manufactured by Dupont
Corporation) fibers are employed in the foregoing representative lay-ups of
the outer
and/or inner layers 430 and 410 of the shaft 20, it is to be understood that
other fibers or
filaments may be employed. Thus for example, it is contemplated that in
addition to
carbon and aramid fibers, fibers made of glass, polyethylene (such as Spectra
manufactured by Allied Signal Corporation), ceramic (such as Nextel~
manufactured by
3m Corporation), boron, quartz, polyester or any other fiber that may provide
the desired
strength may be employed. Preferably, at least part of one of the fibers is
selected from
the group consisting of carbon fiber, aramid, glass, polyethylene, ceramic,
boron, quartz,
and polyester; even more preferably from the group consisting of carbon fiber,
aramid,
glass, polyethylene, ceramic, boron, and quartz; yet even more preferably from
the group
consisting of carbon fiber, aramid, glass, polyethylene; ceramic, and boron;
yet even more
preferably from the group consisting of carbon fiber, aramid, glass,
polyethylene, and
ceramic; yet even more preferably from the group consisting of carbon fiber,
aramid,
glass, and polyethylene; yet even more preferably from the group consisting of
carbon
fiber, aramid, and glass; yet even more preferably from the group consisting
of carbon
fiber and aramid; and most preferably comprises carbon fiber.
It has been found preferable, as can be surmised from the foregoing tables,
that it is
preferable for the lay-up of the shaft to include groups of parallel fibers
oriented in
different directions. Hence, for example the plurality of plies that form
inner layer 410
include plies having uni-directional fibers oriented in a first direction and
plies having uni-
directional fibers oriented in a second direction that is different than the
first.
The matrix or resin-based material in which the fibers are disposed may be
selected
from a group including: (1) thermoplastics such as polyether-ketone,
polyphenylene
sulfide, polyethylene, polypropylene, urethanes (thermoplastic), and Nylon-6,
and (2)
thermosets such as urethanes (thermosetting), epoxy, vinyl ester, polycyanate,
and
polyester. In the preferred construction set forth above thermoset resins have
been
satisfactorily employed.
In addition, it has been found preferable that the plies of fibers be pre-
impregnated
with a resin prior to being layered over one another and the mandrel. By so
doing, it has
been found that the lay-up of the plies is facilitated in that each ply is
capable of acting as
a tape and adhering to the preceding ply and hence may serve to facilitate the
fixing of the
CA 02484806 2004-10-14
12
relative position of the pre-cured plies to on another. In this regard,
suitable materials
include: (a) uni-directional carbon fiber tape pre-impregnated with epoxy,
manufactured
by Hexcel Corporation of Salt Lake City, Utah, and also S & P Systems of San
Diego,
California, (b) uni-directional glass fiber tape pre-impregnated with epoxy,
also
manufactured by Hexcel Corporation, (c) uni-directional KevlarTM fiber tape
pre-
impregnated with epoxy, also manufactured by Hexcel Corporation, (d) 0/90
woven
Kevlar~ fiber tape pre-impregnated with epoxy, also manufactured by Hexcel
Corporation, and (e) 0/90 woven carbon tape pre-impregnated with epoxy, also
manufactured by Hexcel corporation.
With respect to the middle elastomer layer, the term "elastomer" or
"elastomeric",
as used herein, is defined as, or refers to, a material having properties
similar to those of
vulcanized natural rubber, namely, the ability to be stretched to at least
approximately
twice its original length and to retract rapidly to approximately its original
length when
released. Hence, materials that fall within the definition of "elastomeric" as
used and
described herein include materials that have an ultimate elongation equal to
or greater than
100% in accordance with the following formula:
(1) Ultimate Elongation Percentage = f [(final length at rupture) -
(original length)] = [original length] } x 100
Where: Ultimate Elongation: also referred to as the breaking elongation, is
the
elongation at which specimen rupture occurs in the application of continued
tensile stress
as measured in accordance with ASTM Designation D 412 Standard Test Methods
for
Vulcanized Rubber and Thermoplastic Elastomers - Tension (August 1998).
Such elastomer materials may include: (1) vulcanized natural rubber; (2)
synthetic
thermosetting high polymers such as styrene-butadiene copolymer,
polychloroprene
(neoprene), nitrile rubber, butyl rubber, polysulfide rubber ("Thiokol"), cis-
1, 4-
polyisoprene, ethylene-propylene terpolymers (EPDM rubber), silicone rubber,
and
polyurethane rubber, which can be cross-linked with sulfur, peroxides, or
similar agents to
control elasticity characteristics; and (3) Thermoplastic elastomers including
polyolefins
or TPO rubbers, polyester elastomers such as those marketed under the trade
name
"Hytrel" by E.I. Du Pont; ionomer resins such as those marketed under the
trade name
"Surlyn" by E.I. Du Pont, and cyclic monomer elastomers such as di-cyclo
pentadiene
(DCPD).
CA 02484806 2004-10-14
13
In addition, one criteria for assessing the appropriateness of an elastomer is
its
ability to be molded to the materials that form the inner and outer layers
between which it
is disposed. In the exemplary hockey shaft construction described above, it
has been
found that the following exemplary elastomer is capable of being employed
successfully:
Material: Styrene Butadiene Rubber Latex
Supplier: Diversified Materials Company, La Mesa, California
Hardness HS (JIS-A}: 65+/-5
Elongation Percentage: 200 or above
Tesnile Strength: 100 Kgf/cm2 or above
180 Peel Value: 10 kgf/25mm or above
Weight: 180 g/m2
Notably, applicants have found that the employment of intermediate elastorner
layer in a composite hockey stick shaft may impact or dampen the vibration
typically
produced from such shafts and thereby provides a means for controlling or
tuning the
vibration to produce or more desirable feel.
FIG. 16B is a flow chart detailing preferred steps for manufacturing the
hockey
stick shaft 20, prior to joining the shaft 20 to the blade 30 in accordance
with the preferred
manufacturing process described in FIG. 16A. In general a mandrel, dimensioned
to have
the desired internal dimensions of the tubular hollow 230 of the shaft 20, is
provided (step
600). The mandrel is overlaid with a plurality of pre-impregnated plies of
fibers which
forms the inner layer 410 of the hockey stick shaft 20 (step 605). The inner
layer 410 is
then overlaid, at the desired location or locations, with a sheet of elastomer
material,
which forms the middle elastomer layer 420 of the hockey stick shaft 20 (step
610). The
middle elastomer layer 420 is then overlaid with a plurality of pre-
impregnated fiber plies,
which form the outer layer 430 of the hockey stick shaft 20 (step 61 S). The
un-cured shaft
pre-form is then placed within a female mold and heat is applied to cure the
shaft 20 over
the mandrel. The mandrel is then removed from the cured shaft 20 (step 625).
The middle elastomer layer 420 may extend the full longitudinal length of the
shaft
20 and/or on each of the four side walls (i.e. wide walls 150 and 160 and
narrow walls 170
and 180) of the shaft 20 at any given cross-section of the shaft 20. It is
contemplated,
CA 02484806 2004-10-14
14
however, that the middle elastomer layer 420 may extend only along one or more
discrete
longitudinal portions of the shaft 20 and/or one or more discrete wall regions
of the shaft
20.
Hence it is contemplated that the middle elastomer layer 410 may form any
portion
of a wall of the shaft 20 without necessary forming any other portion or wall
of the shaft.
Thus, for example, it is contemplated that middle elastomer layer 410 may, at
any given
cross-section of the shaft 20, form: (a) wide wall 150 and not wide wall 160
and/or narrow
walls 170 and 180, (b) narrow wall 170 and not narrow wall 180 and/or wide
walls 150
and 160, (c) narrow wall 170 and wide wall I50 but not narrow wall 180 nor
wide wall
160, (d) narrow wall 170 and 180 but not wide walls 150 and 160, (e) wide
walls 150 and
I60 but not narrow walls 170 and 180; and (f) narxow wall I80 and wide'wall
150 but not
narrow wall 170 nor wide wall 160.
With respect to the longitudinal positioning of the middle elastomer layer
reference
is made to FIG. 21. Illustrated in FIG. 2I is a hockey stick 10 having a
longitudinal length
LS (L-HS), a shaft 20 having a longitudinal length (L-S), a first longitudinal
length (LI)
extending from the lower end of the shaft 20 or hockey stick 10 (i.e.,
including the blade
30), and a second longitudina.I Length {L2) extending upward from the
termination of the
first longitudinal length (L 1 ) to the upper terminal end of the shaft 20. It
is preferable that
at least a portion of the middle elastomer layer 420 reside within
longitudinal length L1;
where LI = L-HS, even more preferably where L1 = 0.75 x L-HS; even more
preferably
where L1 = O.S x L-HS, even more preferably where L1 = 0.25 x L-HS, yet even
more
preferably where L1 is 0.20 x L-HS, yet even more preferably where L1 is O.IS
x L-HS,
yet even more preferably where L1 is 0.1 x L-HS. Alternatively, it is
preferable that at
least a portion of the middle elastomer layer 420 reside within longitudinal
length L1;
2S where L1 = L-S, even more preferably where Ll = 0.75 x L-S, even more
preferably
where L1 = 0.5 x L-S, even more preferably where Ll = Ø25 x L-S, yet even
more
preferably where L 1 is 0.20 x L-S, yet even more preferably where L 1 is 0.1
S x L-S, yet
even more preferably where LI is O.I x L-S. Thus, for example if the
longitudinal length
of the hockey stick (L-HS) is 63 inches and the longitudinal length of the
hockey stick
shaft (L-S) is 60 inches long, then where L1 = 0.1 S x L-HS = 9.45 inches or
in other words
it would be preferable that the elastomer layer, or at least a portion
thereof, reside along
the shaft within 9.45 inches of the tip of the blade 30. Where L 1 = 0.1 S X L-
S = 9 inches
or in other words it would be preferable that the elastomer layer, or at least
a portion
thereof, reside along the shaft within 9.0 inches of the terminal lower end
335 of the shaft
3S 20. In the exemplary construction lay-up described, it has been found that
the
CA 02484806 2004-10-14
employment of an 8 inch elastomer sheet, formed of the above-identified
exemplary
elastomer, extending from the terminal lower end 335 of the shaft upwards and
around
each of the four sides or walls of the shaft 20 is capable of providing
suitable results.
FIGs. I4 and 15 are cross-sectional views taken along line 14---14 and line 15-
-15
5 of FIG. 3 and illustrate in more detail the construction configurations of
the hockey stick
blade 30. It is to be understood that the configurations illustrated therein
are exemplary
and various aspects, such as core element 400 configurations or other internal
structural
co~gurations, illustrated or described in relation to the various
constructions, may be
combined or otherwise modified to facilitate particular design purposes or
performance
10 criteria. The construction of the blade 30 will now be described with
reference to FIG.
16C, which is a flow chart detailing preferred steps for manufacturing the
hockey stick
blade 30. Generally, one or more plies of fibers 450, preferably uni-
directional
substantially parallel fibers pre-impregnated with a resin matrix as
previously described,
are wrapped over one or more core elements 400 having the general shape of the
hockey
15 stick blade 30 (step 630) to form an initial blade pre-form. The core
elements 400 may be
comprised or wholly formed of ( 1 ) formulations of expanding syntactic or non-
syntactic
foam such as polyurethane, PVC, or epoxy, (2) wood, (3) elastomer or rubber,
and/or (4)
bulk molding compound (i.e. non-continuous fibers disposed in a matrix or
resin base
material, which when cured become rigid solids). Thus, it is contemplated
there be
multiple core elements 400 of which some may be made of a first material, for
example
foam, while others may be made of second material, for example an elastomer or
rubber.
After the initial blade pre-form is formed a spacer element 470 is butted up
against
the rear of the initial blade pre-form such that the spacer element is
positioned to occupy
the heel region of the blade and additional plies of fibers overlain to form a
secondary
blade pre-form (Step 635). The spacer element 470 is dimensioned to generally
correspond to the outer dimensions of the lower regions of the shaft 20
configured to mate
with the blade. The spacer element 470 is then removed from the secondary
blade pre-
form (step 640). FIG. 17 is a diagram that illustrates the spacer element 470
being
removed from the pre-cured hockey stick blade pre-form.
FIG. I6A is a flow chart detailing preferred steps for constructing a unitary
hockey
stick by joining the cured hockey stick shaft (step 645) described above with
the un-cured
secondary hockey stick blade pre-form (step 650). Generally once the spacer
element 470
is removed the cured hockey stick shaft 20 is inserted into the space at the
heel section 140
previously occupied by the spacer element 470 between the front and back walls
90 and
100 of the pre-cured hockey stick blade pre-form as illustrated in FIG. 18
(step 655).
CA 02484806 2004-10-14
a
16
Additional plies of fibers may be overlain about the blade arid around the
heel and lower
end region of the shaft to cover any gaps around the edges or to reinforce any
week
regions around for example the heel region. The cured shaft and the un-cured
blade pre-
form are inserted into the a female mold configured to (a) received the
uncured blade pre-
y form and at least a portion of the lower region of the cured shaft and (b)
having the desired
exterior shape of the hockey stick blade (step 660). FIG. 19 is diagrams
illustrating the
un-cured hockey stick blade and the cure hockey stick shaft assembled in the
open mold
prior to molding and FIG. 20 is an illustration of the hockey stick blade and
cured hockey
stick shaft assembled in the closed mold prior to curing. Once the mold is
closed heat is
applied and the blade is cured around the interposed Lower region of the shaft
(step 670) to
form a unitary one-piece composite hockey stick having a hollow tubulax shaft
that
extends internally within the front and back walls of the blade. The hockey
stick is then
removed from the mold and finished for example via painting or decaling or
perhaps
sanding or grinding any imperfections out from the molded finish.
While there has been illustrated and described what are presently considered
to be
preferred embodiments and features of the present invention, it will be
understood by
those skilled in the art that various changes and modifications may be made,
and
equivalents may be substituted for elements thereof; without departing from
the scope of
the invention. For example, it is contemplated that the composite hockey stick
shaft
having a middle elastomer layer 420 disclosed and taught herein be employed in
hockey
stick shaft configurations disclosed and taught in co-pending and owned U.S.
Patent Serial
Number 10/439,652 filed on May I5, 2003. In addition, it is contemplated, for
example,
that the composite hockey stick shaft having a middle elastomer layer 420
disclosed and
taught herein be employed in hockey sticks having the composite blade
structures
disclosed and taught in co-pending and owned U.S. Patent Serial Number
10/439,652 filed
on May 15, 2003.
1n addition, many modif canons may be made to adapt a particular element,
feature
or implementation to the teachings of the present invention without departing
from the
central scope of the invention. Therefore, it is intended that this invention
not be limited
to the particular embodiments disclosed herein, but that the invention include
all
embodiments falling within the scope of the appended claims. In addition, it
is to be
understood that various aspects of he teachings and principles disclosed
herein relate
configuration of the blades and hockey sticks and component elements thereof.
Other
aspects of the teachings and principles disclosed herein relate to internal
constructions of
the component elements and the materials employed in their construction. Yet
other
CA 02484806 2004-10-14
s
17
aspects of the teachings and principles disclosed herein relate to the
combination of
configuration, internal construction and materials employed therefor. The
combination of
one, more than one, or the totality of these aspects defines the scope of the
invention
disclosed herein. No other limitations are placed on the scope of the
invention set forth in
this disclosure. Accordingly, the invention or inventions disclosed herein are
only limited
by the scope of this disclosure that supports or otherwise provides a basis,
either inherently
or expressly, for patentability over the prior art. Thus, it is contemplated
that various
component elements, teachings and principles disclosed herein provide multiple
independent basis for patentability. Hence no restriction should be placed on
any
patentable elements, teachings, or principles disclosed herein or combinations
thereof,
other than those that exist in the prior art or can under applicable law be
combined from
the teachings in the prior art to defeat patentability.
