Note: Descriptions are shown in the official language in which they were submitted.
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TITLE: wBl~R-R$SIBTl~IaT HOCEBY STICK BLADE, ~1D
METHOD OF MA~B'ACTDRB TH8RE08
Field of the invention
This invention relates to hockey sticks used by
hockey players for striking a ground standing puck toward
the net of the other party, and in particular to a ground
abrasion wear resistant device for hockey stick blades.
Back~ound of the invention
In the case of all-wood hockey stick blades, the
fissures very often start at the lower running edge of the
blade to afterwards expand to the core of the blade where
splitting occurs. The fissures are caused by the friction
of the hockey blade on the ice and on other hockey blades,
and also to the downward load weight thrust applied by the
hockey player on the blade when accomplishing a high
velocity shot on the elastomeric puck (more commonly called
a slap shot) that results in an important edgewise impact
of the blade on the ice. It can be seen that having a
lower running edge made of a rigid metallic alloy
substantially helps prevent this undesirable fissuring from
happening.
This fissuring of the blade happens most
importantly on the lower edge of the blade near the hockey
stick inner heel. This is due to the fact that the elbowed
heel links the blade to the shaft of the stick, and this
critical linking point is the one that is most often
directly touching the ground.
In United States patent No 5,496,027 issued 5
March 1996 in the name of Christian Brothers inc., there is
disclosed a reinforced blade for use as a replacement blade
in a hockey stick. A braided tubular sleeve and resin
material are placed on the blade, including on the
connection end at the top of the replacement blade. The
braided tubular sleeve and resin are moulded in place by a
moulding device. The connection end is then inserted into
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the hollow lower end of a handle. The resulting hockey
stick is more resistant to breakage at the point of
connection. However, such a hockey blade provides little
help in increasing the durability thereof over high-
s abrasion play surfaces such as asphalt or cement surfaces.
In their latest 1997 Catalogue of products, the
same company Christian Brothers inc. now offers a new
product called " XTRA BLADE " . The XTRA BLADE is said to
be available as a complete wood stick or a replacement
blade, and would include an epoxy " wear strip " on the
bottom of the blade. The epoxy appears to fill a full
length slot in the bottom of the wood blade and is applied
in a liquid (melted) state. Once cooled, the epoxy and
wood would bond together as one, to allegedly increase the
overall strength and life of the blade.
There are a number of problems with such a hockey
blade construction. The first one is that the plastic wear
strip is an add-on feature to the grooved lower edge of the
hockey blade, meaning that although it is claimed that they
bond together " as one " , some relative play could
nevertheless appear at the interface therebetween, since
the plastic material appears to be simply engaged into the
groove and would not anchoringly surround any specific
structure; accordingly, the plastic wear strip could be
made to undesirably move relative to the blade proper, or
even could arguably even accidentally detach and fall off
therefrom.
Moreover, although epoxy is more abrasion
resistant than wood, and would accordingly increase the
durability of the blade over an ice rink, its thickness
could still decrease dramatically in a short while due to
abuse relating to alternate rougher ground play surfaces
such as asphalt or cement.
Also, such an epoxy add-on on the wooden blade
means that the wear strip could not be applied to blades
made from a plastic material, due to their common melting
points that would melt the blade groove channel at the
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lower edge of the blade at the same time as when the liquid
wear strip is applied, thus deforming the groove and
therefore rendering the latter inoperative for its purpose
of retaining the wear strip to the blade lower edge.
~l~i i,, ets of it,he invention
The main object of the invention is to control
the wear of hockey stick blades, particularly over very
rough high-abrasion ground play surfaces.
Another important goal of this invention is to
substantially extend the useful lifetime of a hockey stick
blade over high abrasion ground surfaces, while maintaining
the mechanical longitudinally flexing required properties
of the blade at optimum levels through the lifetime
thereof.
A further ob j ect of the invention is that this
wear resistant hockey blade could be used in various
applications including as an integral part of a hockey
stick or as a replacement blade, and for forward players as
well as for goal tenders sticks.
Another important object of the invention is to
submnit a manufacturing process of a hockey stick with wear-
resistant blade, of low cost and of lower number of
required steps.
A general object of the invention is to provide
a low-cost hockey stick blade that will be long-lasting yet
will boast high-performance mechanical features that will
remain substantially constant throughout the useful
lifetime of the hockey stick.
An object of the invention is to provide a wear
resistant hockey blade, whose mechanical properties can be
initially adjusted to adapt to hockey players of different
strengths.
$y~a y of the invention
In accordance with the objects of the invention,
there is disclosed a process of manufacture of a blade for
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use as an integral component of a hockey stick, the process
comprising the following steps: a) providing a mould with
at least one compartment having the shape of the hockey
blade, the compartment having a flooring; b) introducing
over the mould flooring an elongated rigid metallic insert,
the insert being thin; c) supporting with transverse core
pins the sheet insert in upright edgewise position; d)
injecting melted plastic into the mould to form a plastic
blade; and e) leaving the plastic blade to set.
Preferably, there is added the step of piercing
a number of flow-through bores through the metallic insert
at step (d), wherein melted plastic flows therethrough
during injection moulding of step (d); and also preferably
the step (f) of grinding the lower edge of the blade, after
release from the mould, to make the lower edge of the
reinforcing insert smooth and flush therewith and exposed.
The invention also concerns the product per se,
namely, a reinforced blade for use as an integral component
of a hockey stick, the hockey stick of the type having a
main tubular shaft, the blade being a generally rectangular
elongated sheet blade having an elbowed neck for integrally
and axially mounting to said main shaft, said sheet blade
having a lower edge defining a straight section and an
inner coextensive elbowed section both adapted to
frictionally engage ground surfaces; wherein said sheet
blade is made from a thermoplastic material and includes an
integral inner reinforcing elongated sheet insert made from
a material with high ground abrasion resistance but with
good longitudinal flexibility, said inner sheet insert
being embedded inside said sheet blade and having an
exposed lower edge extending through said blade lower edge
elbowed section and through at least a coextensive inner
portion of said blade straight lower edge and being flush
therewith, said reinforcing sheet insert imparting enhanced
structural integrity of said sheet blade while enabling
longitudinal flexibility, said sheet insert lower edge
forming a wear-resistant running edge.
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Preferably, the material of said sheet insert is
selected from the group comprising composite aluminum
alloys, aramid materials, stainless steel, and three
registered trademarks: DURALUMIN, KEVLAR, and DURALCAN
5 (from Alcan) .
It is envisioned that ear means be added, for
providing further anchoring force for said sheet insert
into said sheet blade over and above the frictional
mounting therebetween. Said ear means could then be
thermoplastic material studs integral to said sheet blade
and extending through bores made into said sheet insert,
wherein said sheet insert is firmly anchored into the
thickness of said sheet blade.
Alternately, said reinforcing sheet insert could
further include a number of bores, the thermoplastic
material of said sheet blade extending through said sheet
insert bores, wherein said sheet insert is firmly anchored
into the thickness of said sheet blade.
Said sheet insert lower edge should preferably
have a generally convex shape.
BRIEF DESCRIPTION S1F THE DRAWINGS
Figure 1 is an isometric view of a hockey stick,
with the hockey stick blade being partly broken at its
inner elbowed heel section to show the inner section of the
reinforcing running edge metallic insert in accordance with
the teachings of the invention;
Figures 2 and 3 are side elevations of two hockey
sticks, at a smaller scale than in figure 1, suggesting in
phantom lines the relative lengths of two embodiments of
reinforcing metallic inserts embedded into the blade
thereof ;
Figure 4 is a front elevational view of a hockey
stick according to conventional make, suggesting in phantom
lines the swinging motion thereof as a ground standing puck
(also shown in dotted lines) is being struck by the wooden
blade thereof during the " slap shot " strike motion;
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Figure 5 is a free end view at an enlarged scale
of the prior art hockey stick blade of figure 4, suggesting
how the wooden blade thereof becomes quickly damaged after
repeated impacts with the hard rubber puck;
Figure 6 is a view similar to that of figure 4,
but with a hockey stick having the reinforcing metallic
insert embedded in its blade according to the invention;
Figure 7 is a view similar to that of figure 5,
but with the hockey stick blade of figure 6 shown after the
repeated impacts with the hard rubber puck, suggesting that
the blade has remained substantially undamaged;
Figure 8 is an enlarged scale side elevational
view of the hockey stick blade according to the embodiment
of figure 2, suggesting in phantom lines the full length
metallic reinforcing insert embedded along the lower edge
portion thereof;
figure 9 is a plan view of the first embodiment
of full length elongated metallic insert shown in dotted
lines in figure 8, and clearly also showing the two
opposite convex end edges and the number of bores through
which is adapted to flow melted plastic during the
manufacturing process thereof;
Figure 10 and 11 are edge views of the hockey
stick blade of figure 8, suggesting the relative lengthwise
flexibility of the blade including its full length metallic
insert under forcible manual bias from the hand of a
person;
Figures 12 and 13 are edge views similar to
figures 10 and 11, except that they apply f or the first
embodiment of shorter lengthwise metallic insert;
Figure 14 is a view similar to figure 9, but for
the second embodiment of shorter lengthwise metallic insert
suggested in figures 12 and 13, and clearly showing the
smaller core pin apertures, the larger melted plastic flow-
through bores, the straight corner end edge and the
opposite convex end edge thereof;
Figure 15 is an isometric view at an enlarged
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scale of the hockey stick blade with the full length rigid
insert embodiment shown in dotted lines;
Figure 16 is a sectional view of the hockey stick
blade taken along the line 16-16 of figure 15 that extends
through the flow-through bores of the blade;
Figure 17 is an elevational view of a mould
assembly for moulding the hockey stick blade by plastic
injection moulding, the mould assembly being in open
condition;
figures 18 and 19 are cross-sectional views of
two different embodiments of mould assembly in closed
condition, respectively having two and four blade-forming
compartments;
Figure 20 is an enlarged view of a broken section
of the mould assembly of figures i8 or 19, showing a single
compartment before plastic injection moulding, and
suggesting that the full length elongated metallic insert
is supported in upright condition. at the flooring thereof
by transverse (horizontal) core pins shown in cross
section; and
Figure 21 is an enlarged sectional view of the
rigid insert taken along line 21-21 of figure 20, and
showing in full lines the transverse supporting core pins
on opposite lateral sides thereof, together with the mould
assembly elements in cross-section.
DETp~T_T_,ED DESCRIPTIOIiLOF THE pREFER_RED EMBODIMENT
The hockey sticks 31, 31', shown in figures 1-3
each consists of a straight elongated shaft 30 and a blade
32 having an integral elbowed neck or heel 34 fixedly
axially mounted to the shaft 30. The length of the shaft
30 is in relation to the height of the hockey player. In
operative position, the blade 32 stands edgewisely upright,
so that its bottom edge 32a including that of heel 34 form
a running edge that transversely slides over the ground ice
and even strikes thereover during swinging motions to
strike a ground standing puck P to impart forward velocity
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thereto. As the blade running edge 32a impacts upon the
ground ice during its swinging motion, and immediately
after ground impact, it strikes the hard rubber puck,
considerable loads are applied thereto which tend to
compromise the structural integrity of the blade 32, in
particular at the heel or elbow tenon and mortise joint
section between the blade 32 and the shaft 30.
The plastic material of the blade provides the
lengthwise flexibility for providing predictable " slap
shots " against ground-standing hard rubber pucks, whereas
the fibreglass layers provides protection of the wood
against impact damage. The. blade heel 34 is conventionally
axially secured to the shaft 30 by complementary tenon and
mortise joints at their registering ends, and the
reinforcing fibreglass sheets are made to extend over this
joint to permanently anchor the blade to the shaft in the
selected angular orientation.
Alternate hockey sticks include those with a
replaceable blade having a socket for axially receiving the
shaft inner end in relasable fashion.
Now, according to the invention, there is
provided an elongated generally rectangular insert sheet
plate of metallic alloy 36 within the lower edge portion of
the sheet blade 32 including a coextensive heel section.
The plane of the metal sheet plate 36 is parallel to that
of the generally rectangular sheet blade 32, so that the
lower running edge 36a of the metal plate project through
the centre of the lower running edge 32a of the blade 32
and become flush therewith and exposed. In the first
embodiment of blade 32 in figure 2, the metallic insert
plate 36 extends along the full length of the blade lower
edge 32a, including the adjacent coextensive section of
heel 34, whereas in the second embodiment of blade 32' in
figure 3, the metal insert plate 36' including the heel 34
extends from only a fraction of the way toward the free
front end tip 32b of the blade, e.g. half way.
Figures 4-7 suggest how the structural integrity
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of the blade 32 can be more predictably monitored in the
long run than with prior art hockey stick blades. On the
other hand, figures 10-13 suggest that this increased
resistance in the blade does not affect the lengthwise
flexibility of the blade 32 required for predictable and
optimum performance " slap shots " by hockey players.
Figures 9 and 14 show in detail the two different
embodiments of metallic strip inserts.
The first embodiment of full length insert 36,
shown in dotted lines in the hockey blade of figure 2 and
in full lines in figure 9, forms a generally rectangular,
thin, flat, elongated sheet plate, having a first convex
bottom edge 36a and a straight " top " edge 36b merging at
its two opposite ends with the convex bottom edge 36a. The
insert plate 36 includes a number of large transverse bores
38, for a purpose later set forth. The insert plate 36 is
sized to substantially match the contour of the blade lower
edge 32a, wherein the convex bottom edge 36a of the insert
plate can exactly become in register and flush with the
bottom edge 32a of the blade proper, including the adjacent
coextensive heel portion, so as to become downwardly
exposed as a separate intermediate layer inside the blade.
Accordingly, ground ice contact of the blade 32 during slap
shots with the hockey stick will be made by the bottom
convex edge 36a of the metallic intermediate insert,
concurrently with the bottom edge 32a of the blade proper,
including that of the adjacent coextensive heel portion 34.
Alternately, it would still be considered within
the scope of the present invention that the hockey stick be
sold with the metallic insert bottom edge 36a being
unexposed i.e. with some blade plastic lip overlapping
same; but that after the wearing action of a few abrasive
slap shots, the metallic insert running edge 36a would
become exposed progressively during use by a player.
However, the joint applicants prefer the concept in the
first embodiment of providing the blade 32 with the
metallic insert running edge 36a being already exposed
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without wear required, already at the retail store level.
The rigid insert plate 36 must be made from a
material having high abrasion resistance and that imparts
added structural integrity to the blade 32, while providing
5 optimum lengthwise flexibility in accordance with
mechanically satisfactory loading and unloading features to
provide powerful yet direction-predictable properties
thereto while constantly maintaining these properties
within a narrow range of fluctuation in a long-lasting
10 fashion.. Preferred materials would include but not be
limited to: Composite aluminum alloys, DURALUMIN (a
registered trademark), aramid materials, KEVLAR ( a
registered trademark), stainless steel, DURALCAN (a
registered trademark of Alcan Aluminum ltd), and the like.
The DURALCAN material is especially preferred.
Indeed, it is an aluminum-matrix composite based on
aluminum-silicon alloys, containing silicon carbide and~or
aluminum oxide particulates. Abrasion and wear resistance
is very high, while the ratio of elastic modulus remains
very good. The melting range of a DURALCAN-based insert 36
would therefore be at least 525°C, i.e. much higher than the
AHS or other plastic material constituting the hockey blade
main material.
An important consideration in the selection of
the insert material is that its melting point should be
substantially different from that of the plastic material
of blade proper, so that as it becomes embedded into the
melted plastic during moulding operation, the insert
retains its shape but bonds integrally to the plastic
volume.
During experiments conducted by the point
applicants, a pair of hockey sticks were fixedly attached
to the rear of a pick-up truck, their blade upright against
the ground, with one hockey stick blade being of
conventional ABS plastic material while the other being
reinforced at its blade by a metallic insert according to
the present invention. The metallic insert in this blade
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was made of DURALCAN and had a thickness of about 1.27
millimetres. The truck was powered and driven at 20 km\hour
f or one hour ( ie . over 2 0 kilometres ) , bef ore the hockey
sticks were released therefrom. Measures taken of the
abrasive effect edgewisely on the bottom edge of two
upright hockey stick blades revealed that the wear-borne
relative thickness loss of the blades was 0.25 mm in the
case of the present reinforced hockey blade, while that of
the conventional unreinforced hockey blade was 5.75 mm,
i.e. 23 times that of the reinforced blade.
Obviously, the thickness of the metallic insert
36 could vary from the above-noted thickness. For optimal
performance, it is estimated that the range of metallic
insert thickness for DURALCAN would be between 0.6 to 1.3
mm, but a hockey blade with a DURALCAN insert smaller than
the lower value or larger and the higher value would still
be operative and a good although not optimum hockey stick.
The second embodiment of shorter yet still
elongated metallic insert 36' is illustrated in phantom
lines in figure 3 and in full lines in figure 14. Insert
36' extends for only a fraction of the full length of the
lower edge portion of the blade 32' . Insert sheet plate
36' includes a top straight edge 36'b, a bottom straight
edge section 36'a, a front end square corner edge 36'c
generally orthogonal to edges 36'a and 36'b, and a rear
convex end edge 36'd coextensive to the bottom straight
edge 38'a. Small flow through bores 38' are further
provided. As in the first insert 36, sheet insert 36' is
thin, flat, generally rectangular in shape, and still quite
elongated. Core pin notches 40 are also shown on the sheet
insert 36', for a purpose that will be described
hereinbelow.
In both embodiments of reinforcing sheet inserts
36, 36', it is an important feature of the invention that
the inner end heel section (i.e. opposite the side of the
free end tip 32b of the blade) of the lower running edge
36a (36a') be convexly upwardly shaped and exposed, to
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conformingly follow the contour of the elbowed neck 34 of
the blade 32 flush therewith. Indeed, a substantial level
of wear occurs specifically at the heel junction between
the substantially straight bottom edge portion of the blade
32 and the upwardly inclined heel section, 34. Therefore,
any reference in the specification and claims as to the
" lower running edge of the blade 32 and reinforcing inner
insert 36 " is to be understood as being applied to at
least an inner fraction of the length of the lower edge
portion of the blade and to at least a small coextensive
lower edge portion of the elbowed heel or neck 34 of the
blade 32.
Depending on the need of the user, the
reinforcing insert strip 36, which extends from the neck 34
frontwardly at least for a fraction of the total length of
the blade 36, may be extended forwardly up to and including
the full length of the blade, i.e. up to the free end tip
32b of the blade 32.
We will now turn our attention to the
manufacturing process involved in the manufacture of the
present reinforced hockey blade.
Before tenon and mortise assembly of the blade 32
with the shaft 30, the blade 32 is separate. Combining the
reinforcing metallic insert 36 into the blade proper 32 is
performed accordingly with the teachings of the present
method of manufacture, having reference to figures 17 to 21
of the drawings. Basically, the blade 32 is formed in a
mould 50 by injection moulding, with the metal insert 36
being already inside the mould 50 before melted plastic
injection, so that the liquid plastic sets around the metal
strip 36 and therethrough i.e. through bores 38 and the
insert 36 becomes embedded therein.
More particularly, the mould 50 consists of a
stationary element 52 and a second element 54 movable
relative to the stationary element 52 (either toward or way
therefrom). Each mould main element 52, 54, conventionally
carries its inner plate 58, 60. The mould 50 further
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includes one or more hollow compartments 56 (e.g. two in
figure 18, or four in figure 19), each compartment 56
having the shape of a hockey blade. The flat flooring 56a
of each compartment 56 is conformingly adapted to
edgewisely support in upright position the rectangular thin
insert sheet plate 36, or 36', with a plurality of core
pins 42 being provided integral to the mould lateral walls
to transversely engage at notches 40 (fig 14) and support
the lateral walls of the rigid insert plate 36 so as to
prevent accidental lateral tilt of the latter from its
upright condition. The centre to centre gap between each
successive pairs of core pins 42, 42, should not exceed 3
cm, so as to allow a sufficient level of support during the
liquid plastic filling operation inside the mould.
Each of the pair of registering core pins 42, 42,
has a shoulder, 42a, to enable the mould operator to
position the insert plate 36 on the stationary element 52
of the mould 50. Upon closure of the mobile element 54 of
the mould 50 against the stationary element 52, seal off
occurs with the core pins 42 from the mobile mould element
54. Liquid (melted) plastic is then fed to the mould
compartments 56 via flow through channels 57 made in the
walls of the mould 50.
Curing of the plastic (e. g., ABS moulding) thus
occurs not only around the edgewisely upright sheet insert
36, but also through the insert (by flowing through the
bores 38), thus in effect firmly and permanently anchoring
the insert 36 in position to the blade proper 32.
Therefore, once the blade plastic has set, the narrow
cavity formed by the insert 36 through the lower edge 32a
of the blade 32 will not allow accidental gravity-borne
sliding release of the insert 36 from the blade 32, since
the insert 36 is hooked or suspended to the blade 32 by the
tubular ear studs formed by the liquid plastic that had
flowed through the flow-through bores 38 during the
injection moulding and that has now become solid.
The ejection of the moulded blade component is
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performed with the help of standard-issue ejectors,
actuated by the usual ejection member. Then, a final step
can be performed in the grinding of the lower edge of the
blade, to make the lower edge of the reinforcing insert
flush therewith and exposed.
Therefore, the present process for manufacturing
a hockey blade does not require the manufacture of a blade
with an elongated groove or notch along its lower edge
portion, for afterwards receiving the metallic insert as a
second step. Rather, the present manufacturing process
does not generate a groove in a blade, but simply includes
the metallic insert during the manufacturing process of the
blade to be integrated therewith as a combined single
manufacturing step.
The manufacture of the hockey blade of the
invention consists in injection moulding of the light alloy
steel or aluminum insert plate 36 into a conventional
plastic mould 50. The plastic could be any suitable type
of thermoplastic material, e.g. ABS.
The main purpose of this reinforced blade 32 is
to provide a good hockey stick for use over high-abrasion
ground surfaces, in particular asphalt or cement, but not
excluding ground ice or other similar surfaces such as
tennis courts with hard rubber surfaces, hard wood surfaces
in interior gymnasiums, or the like ground play surfaces.
The present reinforced blade can be used in a
variety of applications, including as an integral component
of a hockey stick (for players or goalies) , as well as a
separate replacement blade for replacing worn out blades
than can be released from the socket end of the shaft of
reusable hockey sticks.
Moreover, additional features could be added to
the blade without limiting the scope of protection for this
invention. For example, it would be envisioned to provide
a recess or even an aperture into the intermediate central
portion of the hockey blade main plastic body 32, at a
distance from the metallic insert 36, so as to accommodate
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a wooden panel (not illustrated). This wooden panel would
be fixedly connected to the plastic blade main body 32,
coplanar therewith and within the recess or aperture, e.g.
with the usual add-on fiberglass sheathings strips
5 surrounding the blade a number of times . Such an add-on
grainy wooden panel would enhance the good looks of the
hockey stick.
