Note: Descriptions are shown in the official language in which they were submitted.
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COMPOSITE HOCKEY REPLACEMENT BLADE AND METHOD
The present invention relates generally to hockey stick blades and their
manufacturing, more
particularly, to blades of fibre reinforced composite materials which are
suitable for use in both ice
and off ice hockey.
BACKGROUND OF THE INVENTION
Traditionally, hockey sticks for use in ice hockey have been made of selected
woods with
careful attention paid to the quality and orientation of the wood grain for
each of the stick
components. Developments to improve the stiffness and strength of the stick
have included improved
quality control of the woods used, lamination of the shafts and the bonding of
glass, carbon and other
fibers to the exterior faces of the shaft and the blade. More recently, in an
attempt to obtain strong,
stiff sticks with reduced weight, hollow shafts of aluminum, composite and
hybrids of aluminum and
1 S composite have been developed. Separate, replaceable wood blades are
inserted into these shafts to
form a stick.
Hockey sticks for off ice (in-line and road) hockey typically use wear
resistant acyrlonitrile
butadiene styrene (ABS) blades. These blades are relatively heavy and flexible
and are not
considered suitable for ice hockey although they are extremely wear resistant
and thus suitable for
off ice hockey.
All composite construction ice hockey blades can be stiffer, stronger and
lighter than
conventional wooden blades used in ice hockey, as well as road hockey blades
made of ABS. For
example, a composite blade made of a glass and graphite epoxy skinned
polyurethane foam core can
weigh as low as 160 grams and have stiffness as high as 75 kN/M while a high
performance wood
blade weighs 185 grams with a stiffness of 43 kN/M. The lighter, stiffer foam
cored composite blade
provides the hockey player with a tool that can generate greater shot
accuracy. However, it is not
sufficiently wear resistant for off ice hockey usage.
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A search of the patent literature relating to hockey sticks revealed a number
of patents on
blade technology. Most of these are not closely relevant to the teachings of
the current invention in
that they concern only improvements in standard laminated wood or fiberglass
reinforced wood
blades. These improvements include various tongue and groove connection
mechanisms between
the blade and a wooden shaft and morphology changes such as varying the degree
of curvature of
the blade.
Canadian Patent Application 2,099,853 discloses a method for manufacturing a
composite
blade by injection molding while using a foaming agent mixed with the resin to
make a foam core.
It is clear from the claims that short fibers, rather than long and continuous
fibers, are used in this
process, being mixed with and injected into the mold with the resin. It is
well established that short
fiber reinforced composites have only a small percentage of the strength and
stiffness of the long and
continuous fiber reinforcements that are used in the current invention. The
blade revealed by this
application will have far inferior stiffness, strength, weight and wear
resistance than the current
invention. Further, the foam core employed is known to deteriorate under puck
impacts and does
not have the wear resistance required for off ice hockey and therefore has not
met commercial
success.
Canadian Patent 1,063,747 discloses a composite reinforced blade structure for
a hockey
stick. The composite blade consists of a foam core surrounded by a glass fiber
reinforced plastic
skin. The blade is formed in one piece, and the shaft is then inserted into
this cavity and secured by
an adhesive. The adhesive joint bonding the shaft to the blade will be much
weaker than the joint
of the present invention. The foam core is not wear resistant as is the core
of the present invention
and deteriorates under puck impacts, thus this blade would not be suitable for
off ice use and have
therefore not met commercial success.
United States Patent 4,059,269 teaches a blade with the core consisting of a
single piece of
wear resistant material, such as ABS plastic, with the wear resistant core
exposed below, above and
to the front of the fiber reinforced resin layers which stiffen and strengthen
the blade laterally.
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Experience with the art has shown that blades of this kind are much heavier
than the current
invention because a solid ABS type core is used rather than light weight wood
of the present
invention. This blade would be suitable for off ice hockey but would not
possess the light weight,
stiffness and joint strength required for a high performance ice hockey stick.
United States Patent 4,124,208 discloses a one piece stick with a foam filled
honeycomb core
and metal skins on both blade and shaft, which would be very expensive to
produce, and thus it is
not surprising that it has not been made commercially available.
United States Patent 5,333,857 teaches an all composite stick with a foam
sandwich core
blade. This is representative of a number of commercially available composite
sticks which differ
only in the specific foam core materials and fiber geometry specified in the
patents or used in
commercial production. This type of stick is expensive and suitable for ice
hockey but is not
sufficiently wear resistant to be suitable for off ice hockey.
Experience reveals that 69% of all hockey stick failures occur in the blade
(25%) or at the
junction of the blade and the shaft (44%). Only 31% occur in the shaft itself.
Experience has also
shown that wood blades, whether reinforced with fiber or not, are not
sufficiently wear resistant for
off ice hockey thus they have been superseded by ABS blades and fiber
reinforced ABS blades.
These blades tend to be much heavier than high performance blades used for ice
hockey.
One composite blade design worth noting currently on the market is the Easton
composite
blade which is made by resin transfer molding (RTM) or by a prepeg process.
The RTM process
uses liquid resin resulting in a relatively costly process whereas the prepeg
process uses relatively
costly materials with a limited shelf life. The blades of this design
therefore sell at a premium over
wood blades, typically costing twice as much, and are not therefore meant to
compete directly with
wood blades.
Furthermore, market experience reveals that off ice hockey blades are sold
with both stiffness
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and strength that are 30% lower than the typical high performance ice hockey
blades. This is as a
consequence of design compromises made to increase the wear resistance of the
off ice blades using
current technology and lesser demands of the off ice game i.e. lower puck
weight and less shooting
leverage.
SUMMARY OF THE INVENTION
The present invention overcomes the above shortcomings.
It is accordingly a primary objective of the present invention to provide a
replacement blade
or stick suitable for use in both ice hockey and off ice hockey wherein the
weight is in the lower
range of the best ice-hockey blades, the stiffness is equal to or greater than
the best fiber reinforced
wood ice hockey blades, the wear resistance of the blade is equal to or
greater than of the best ABS
off ice hockey blades and the breaking strength is equal to or greater than
the best wood ice hockey
blades.
It is a further object of the present invention to provide a composite blade
for use with a
hockey shaft which is made of wood or composite, or combination thereof, the
blade characterized
by its durability, weight and an increase in the strength and stiffness of the
blade.
A major benefit of this invention is that the hosel is integrally joined to
the composite blade
under elevated temperature and pressure making a very strong bond in the area
where over 44% of
wooden stick failures occur.
In accordance with an object of the present invention there is provided a
composite blade
design that uses a low cost solid SMC or BMC material having a longer shelf
life and using a light
weight wood core thereby resulting in a low cost process and replacement
blades meant to compete
with wood blades. It should also be noted, that the replacement blade of the
present invention results
in a better performance blade for both ice and off ice hockey for the same
cost as compared to wood
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blades.
In accordance with another object of the present invention there is provided a
hockey
replacement blade comprising: a light weight wood core, including a striking
area and a howl area;
a reinforced moulding compound enclosing said wood core said moulding compound
comprised of
a combination of solid polymer compound with unidirectional and/or random
fibrous oriented and
positioned material; whereby the resulting replacement blade when combined
with a hockey shaft
makes a two-piece hockey stick suitable for both ice and off ice hockey.
In accordance with still another object of the present invention there is
provided a hockey
stick comprising: a light weight wood core, including a striking area and a
howl area; a hockey shaft;
and a reinforced moulding compound enclosing said wood core and said hockey
shaft said moulding
compound comprised of a combination of solid polymer compound with
unidirectional and/or
random fibrous oriented and positioned material; whereby the resulting one-
piece hockey stick is
suitable for both ice and off ice hockey.
In accordance with yet still another object of the present invention there is
provided a method
of manufacturing a hockey replacement blade comprising the steps of: making a
wood core,
including a striking area and a howl area; wrapping said wood core with a
moulding compound
comprised of a combinations of solid polymer compound with unidirectional and
random fibrous
oriented and positioned material; and subjecting said core to heat and
pressure in a precise closed
mould, thereby compression moulding a composite layer over said core; whereby
a replacement
blade is formed which when combined with a hockey shaft makes a two-piece
hockey stick suitable
for both ice and off ice hockey.
In accordance with yet still another object of the present invention there is
provided a method
of manufacturing a hockey stick comprising the steps of: making a wood core,
including a striking
area and a hosel area; making a hockey shaft: wrapping said wood core and said
hockey shaft with
a moulding compound comprised of a combinations of solid polymer compound with
unidirectional
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and random fibrous oriented and positioned material; and subjecting said core
and said hockey shaft
to heat and pressure in a precise closed mould, thereby compression moulding a
composite layer over
said core and said hockey shaft; whereby a one-piece hockey stick is formed
which is suitable for
both ice and off ice hockey.
Further objects and advantages of the present invention will be apparent from
the following
description, reference being made to the accompanying drawings wherein
preferred embodiments
of the invention are clearly shown.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be further understood from the following
description with
reference to the drawings in which:
Figure 1 is a side view of a preferred embodiment of the invention;
Figure 2 is a cross-sectional view along lines A-A of Figure 1; and
Figure 3 is a cross-sectional view along lines B-B of Figure 1 in accordance
with the present
invention;
DETAILED DESCRIPTION OF THE DRAWINGS
Generally illustrated in Figure l, a hockey blade 10 is comprised of a light
weight wood core
11, possibly made of aspen, poplar or balsa, or other similar light weight
woods, said core 11
including a striking area 12 and a hosel area 13, for combining said blade 10
with a hockey stick
shaft made of wood or composite, or combinations thereof. The howl area 13
will be sized to fit the
geometry of the shaft such that the desired finished hockey stick is obtained.
Methods of attaching
the howl 13 to the shaft will be known to those skilled in the art.
The preferred embodiment is the forming of a hockey replacement blade 10
comprising the
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steps of making a lightweight wood core 11, wrapping the core 11 with an outer
continuous layers
of solid polymer unidirectional and random fibrous oriented and positioned
reinforced sheet
moulding compound 20 (SMC) or bulk moulding compound (BMC) thereby completely
enclosing
the striking area 12 and the howl area 13 and subjecting said areas 12 and 13
to heat, between 270-
300°F, and pressure, between 200-1000psi, in a precise closed mould
thereby compression moulding
a composite layer 20 over the entire light weight wood core 11.
The composite material used in the process is preferably solid toughened vinyl
ester resin
with long glass fibers with approximately 63% glass content and/or continuous
glass fiber or other
fibrous materials such as graphite or aramid.
This will provide for a hockey blade 10 having the required strength,
stiffness and weight
therefore making for a blade 10 suitable for both ice and off ice hockey.
Referring to Figure 2, there is shown a light weight wood core 11 with a
composite layer 20
over said core 11. It should be noted that a thicker layer of composite
material may be present at the
bottom 21 of the core 11 as compared to the top 22 in order to further prevent
early wearing out of
said core 11 due to contact with off ice play surfaces, such as asphalt or
cement, which are known
to be more demanding on the bottom 21 of the core 11.
Referring to 3, there is shown a cross sectional view of the hosel area 13
whereby the wood
core 11 is wrapped in a moulding compound, the composite layer, 20. It should
be noted that a
thicker layer of composite could be present at the major howl faces 23 to
further strengthen the howl
13 on the faces of greater stress.
Once the moulding compound 20 is in place over the core 11 and has been
moulded, it is then
possible to attach said blade 10 via its howl area 13 with a hockey shaft
whereby a two-piece hockey
stick with a composite blade is formed which is suitable for both ice and off
ice hockey.
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It is also understood that it might be possible to attach the core 1 I with a
hockey shaft prior
to wrapping said core 11 thereby making for a hockey stick which can then be
completely wrapped,
as one complete unit, with the moulding compound resulting in a one-piece
hockey stick suitable for
both ice and off ice hockey.
The invention may be embodied in other specific forms without departing from
the spirit or
essential characteristics thereof. The present embodiments are therefore to be
considered as
illustrative and not restrictive, the scope of the invention being indicated
by the appended claims
rather than by the foregoing description, and all changes that come within the
meaning and range of
equivalency of the claims are therefore intended to be embraced therein.
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