Note: Descriptions are shown in the official language in which they were submitted.
CA 02228104 1998-01-28
ONE PIECE INTEGRAL ICE HOCKEY STICK AND METHOD
The present invention relates generally to ice hockey sticks and their method ofmanufacturing and, more specifically, to one piece sticks manufactured with a wood shaft
5 molded integrally with a composite sandwich structure blade.
BACKGROUND OF TE~ INVENTION
Traditionally, hockey sticks for use in ice hockey are made of selected woods with
careful attention paid to the quality and orientation of the wood grain for each of the stick
cornponents. The shaft and blade are made from four or more individual pieces of wood. The
conventional manufacturing process for wooden hockey sticks involves a large number of
15 individual operations, up to forty per stick. The separate steps include cutting, planing, sanding,
l~min~ting, tapering, fitting, bonding and finishing of the various wood pieces that make up the
stick, there being typically at least five pieces. If glass fiber or other composite reinforcement
is ~dded to the blades the process typically involves more than forty steps. The processing
involves the use of only approximately twelve minutes of labor, for high volume manufacture,
20 bul from start to finish, the process takes from five to thirty days with a large percentage of that
time required to allow for the drying and curing of adhesive bonding agents.
Developments to improve the stiffness and strength of the stick have included improved
quality control of the woods used, l~min~tion of the shafts and the bonding of glass, carbon and
25 other fibers to the exterior faces of the shaft and the blade. More recently, in an attempt to
oblain strong, stiff sticks with reduced weight, hollow shafts of aluminum, composite and
hybrids of alllminum and composite have been developed. Separate, replaceable fiber reinforced
wooden blades or composite blades are inserted into these shafts to form a stick. These
developments have been effective in improving stiffness and strength but have resulted in
30 increasingly expensive hockey sticks.
CA 02228104 1998-01-28
Hockey sticks for off-ice or road hockey typically use wear resistant butadiene styrene
(AE~S) blades attached to wooden shafts, either fiber reinforced or otherwise. These blades are
heavy and flexible and are not considered suitable for ice hockey although they are extremely
wear resistant and thus suitable for road hockey.
s
All composite ice hockey blades can be stiffer, stronger and lighter than conventional
blacles used in ice hockey, or road hockey blades made of ABS. For example, a composite blade
madle of a glass and graphite epoxy skinned polyurethane sandwich panel can weigh 160 to 180
grarns and have stiffness as high as 75 kN/M while a high performance wood blade with
1() graphite reinforcement weighs about 185 grams with a stiffness of 43 kN/M. The lighter, stiffer
composite blade thereby provides the hockey player with a tool that can generate both improved
stick: h~ndling and shot accuracy.
Figures 1 and 2 reveal the prior art. Figure 1 shows a one piece wooden stick with a
shafi made of wood, l~min~ted wood, or fiber reinforced wood, with an integral blade made of
wood or fiber reinforced wood. It comprises a shaft 11 which is gripped by the hands of the
player and a blade 13 integrally attached to the shaft and used to control and strike the hockey
puck. The bottom portion of the connection between the blade and the shaft is called the "heel"
as denoted by 12 and the opposite end of the blade is called the "toe" which is denoted by 14.
Figure 2 shows a hockey stick comprising a hollow shaft 21, typically of composite,
aluminum, or a combination of the two materials. A separate blade 22 made of wood, fiber
reinforced wood, plastic or fiber reinforced composite which is inserted into the end of the
hollow shaft 21 and held by adhesive, friction fit, or some form of mechanical connection. The
heel 12 and toe 14 are as defined in Figure 1. The extension of the blade which is inserted into
one hollow end of the shaft is called the "tenon" 23. The vertical portion of the blade extending
downward from the tenon 23 to the heel 12 is known as the hosel 24 (sometimes spelled hozzel
or hozzle). A wooden or plastic plug 25 is sometimes inserted in the upper end of the shaft 21
opposing the blade end.
CA 02228104 1998-01-28
' ~,
The prior art as expressed in patents, patent applications and commercial literature
reveals some inconsistencies in the terminology used to describe hockey stick components. ln
particular, both the shaft and the end plug are sometimes referred to as the "handle" of the stick.
The tenon is sometimes referred to as the shank. This application will conform to the definitions
S of Figures 1 and 2.
C~n~ n Patent Application 2,037,273 discloses a method for manufacturing a hockey
stic,k from preforms for both the composite blade and a composite shaft and molding the two
preiorms together in a final step. This is a method for producing an all composite stick using
1() a 12 step wrapping and molding process. The use of all composite construction and a 12 step
process results in an expensive all composite stick.
C~n~ n Patent Application 2,057,663 discloses a foam core hockey stick with aramid
and carbon face sheets over the core. This is also an entirely composite stick.
15;
C~n~ n Patent Application 2,062,635 describes the manufacture of an all composite
hockey stick from a separately manufactured composite shaft and blade.
Canadian Patent Application 2,099,853 discloses a method for manufacturing a composite
20 blade by injection molding. The blade is designed to be inserted into a hollow shaft, preferably
a ho;llow metal shaft.
C~n~di~n Patent Application 2,108,069 discloses a method for manufacturing a composite
hockey stick shaft with a metallic insert embedded at one end to accept a separate blade and a
25 standard wooden end plug at the opposite end of the shaft. The patent refers to this end plug as
a "wooden handle" but it is clear from the description and figures that this is an end plug in a
hollow composite shaft. The composite shaft disclosed by this application is not integrally
formed with a blade.
CA 02228104 1998-01-28
C~n~ n Patent Application 2,117,987 discloses a method to injection mold sports
implements such as cricket bats or golf club heads with inserts into the casting. The molded
matcrial is not reinforced with continuous fibers as required to provide stiffness to hockey stick
corr,ponents.
j
C~n~ n Patent 1,063,747 discloses a composite reinforced blade structure for a hockey
stich. The composite blade consists of a foam core surrounded by a glass fiber reinforced plastic
skin. The blade is formed with a "handle receiving cavity" molded into it. A metal insert is
used to form this cavity. The blade is formed in one piece, and the shaft is secured to the cavity
10 by adhesive in a subsequent separate operation. ~t is not clearly stated that the metal insert is
removed to form the cavity but that is implied. A shaft is then inserted into this cavity and
secured by an adhesive. This patent refers only to glass fiber reinforcement. The adhesive joint
boncling of the shaft to the blade results in a much weaker joint than the one of the present
invention.
Can~ n Patent 1,233,738 discloses a method for manufacturing a hockey stick with the
outer layers of both the blade and the core consisting of fiber composite material. The entire
stick is molded in one piece. The blade can contain a wooden core, or a plastic foam core. The
shaft is formed over a mandrel, which can be removed, leaving a hollow composite shaft, or
20 over a foam core, which can be left in place. The result is a hollow or foam cored composite
shaft formed to a composite blade with a wood or foam core.
United Sta.tes Patent 4,124,208 discloses and one piece stick with a foam filled
honevcomb core and metal skins on both blade and shaft.
United States Patent 4,537,398 discloses a fiber reinforced wooden blade molded
integrally with a fiber reinforced wooden shaft. This results in a typical fiber reinforced wooden
stick. The core of the blade is made of wood. The manufacturing process involves all of the
various steps required to manufacture a wooden stick with added steps to apply the composite
30 reinforcement.
CA 02228104 1998-01-28
United States Patent 5,050,878 discloses a polyvinyl chloride (PVC) foam core stick
where the core is wrapped in glass and carbon composites.
United States Patent 5,160,135 reveals another exarnple of a wooden stick with composite
:5 reinforcement applied to an all wooden stick. The core of the blade is also made of wood.
United States Patent 5,217,221 discloses a one piece composite stick with a wooden
veneer molded to cover the entire outer surface of the stick. Both the shaft and blade underneath
the wood veneer are molded of composite material.
1()
SUMMARY OF THE INVENTION
The present invention overcomes the above shortcomings.
Accordingly, an object of the present invention is to provide a method of manufacturing
a one piece integral hockey stick and thereby a resulting one piece hockey stick with an
extremely strong jioint between a wooden shaft and a composite blade which is manufactured by
a fast, low cost method and which is lighter, stiffer and more impact resistant than conventional
20 wooden sticks and less expensive than all composite sticks. This hockey stick uses a conventional
wood, l~min~ted wood or fiber reinforced wood shaft. There is no innovation claimed with
respect to the shal't except as regards the method by which it is manufactured into the integral
stick with a composite blade. The shaft is of conventional hockey stick shaft dimensions and is
of a generally rectangular cross section. The edges can be radiused or beveled. The faces of the
25 shaft, can be slightly concave or convex, or combinations of concave, convex. Reinforcing
sheets or continuous fiber reinforced plastic, can be applied to the faces of the shaft in the
conventional manner or they can be attached by a wet roving application process followed by
molding with applied heat and pressure. There is no innovation claimed as to the use of fiber
reinforced plastic on the faces of the shaft.
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In accordance with another object of the invention there is provided a one piece integral
ice hockey stick which is the combination of a composite blade with a conventional wood or a
l~min~ted glass-wood shaft in a one piece construction. It is lighter than a regular wood hockey
stick and it has a. stiffer blade to allow for improved stick handling, more accurate shooting and
5 a longer life, as the wood blade generally breaks before the wood shaft whereas the composite
blade is stronger than the typical wood blade. The prior art 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 %
of iailures occur in the shaft itself. Thus a process that joins a high performance blade to a
conventional wooden shaft with a high strength bond could be projected to extend the average
10 life of a hockey stick by over 200% while offering improved playing performance from the
stiffer, lighter composite blade as compared to the standard wood blade. A major benefit of this
invention is that the wood shaft is integrally joined to the composite blade under elevated
temperature and pressure, hence the resin penetrates the wood to a depth of several millimeters
making a very strong bond in the area where 44% of wooden stick failures occur. As well,
15 360''composite reinforcement surrounds all four faces further integrally strengthening this key
hosel area.
In accordcmce with still another object of the invention there is provided a one piece
integral ice hockey stick which is suitable for use in ice hockey which provides strength,
20 stiffiless and feel approaching that of expensive, all composite sticks at a cost competitive with
low cost wooden sticks of far inferior strength and puck shooting accuracy.
In accordance with still another object of the invention there is provided a method to
reduce the time and number of manufacturing steps required to produce a hockey stick. The
25 stick is manufactured using less than one quarter of the typical forty steps required to
manufacture a good quality wood or fiber reinforced wood stick. Thus a one piece hockey stick
with an extremely strong joint between a wooden shaft and a composite blade is claimed which
is manufactured bly a fast, low cost method and which is lighter, stiffer and more impact
resist.~nt than conventional wooden sticks and less expensive than all composite sticks.
CA 02228104 1998-01-28
.
In accordance with yet another object of the present invention there is provided a method
of rn~m]facturing an integral hockey stick comprising the following steps: a) shaping the end of
a wooden shaft; b) making a foam blade preform; c) attaching said preform to the shaft; d)
mo]ding the blade to the shaft; and e) trimming the stick: whereby a wooden shaft and a
:5 composite blade are integrally bonded in one operation to form a one piece hockey stick.
In accordance with still yet another object of the present invention there is provided a one
piece ice hockey stick comprised of a wooden shaft and a composite blade where the composite
blad.e is manufactured and integrally bonded to the shaft in one operation resulting in the
1() formation of a strong bond between the blade and the shaft due to the penetration of resin into
the surface layers of the shaft under elevated temperature and pressure, as well as having
360~'composite reinforcement surrounding all four faces further integrally strengthening a hosel
area.
Further objects and advantages of the present invention will be apparent from the
follcwing description, reference being made to the accompanying drawings wherein preferred
embodiments of the invention are clearly shown.
BRIEF DESCRIPTION OF THE DR~WINGS
The present invention will be further understood from the following description with
25 reference to the drawings in which:
Fig. 1 is a side view of a conventional one piece stick used to illustrate the component
terminology;
Fig. 2 is a side view of a typical stick assembled from a separate shaft, blade and end
30 plug, used to illustrate the component terminology;
CA 02228104 1998-01-28
:
Fig. 3 is a longitudinal section through one preferred embodiment of an integral one piece
stick made according to the present invention; and
Fig. 4 is a transverse longitudinal cross section of the blade and shaft of Figure 3 taken
5 along line 41-41 in Figure 3 and a blow-up of part of the cross-sectioned blade.
DETAILED DESCRIPTION OF THE DRAWINGS
1()
The preferred embodiment of the invention is the integral forming and bonding of a
wood or reinforced wood shaft of any construction to a composite sandwich structure blade of
any construction using any suitable core material and any combination of fiber resin
rein]Forcements in. the skins that will provide the required strength, stiffness and weight of the
15 blade while ensuring a very strong bond to the shaft insert around which the blade preform was
constructed.
Different hockey players require different weights and stiffnesses of stick and blade. Thus
the choice of fiber architecture, that is fiber type, locations and orientations, will depend on the
20 player's requirements. The process is suitable for use with a very wide range of cores and fiber
architectures. One preferred embodiment to illustrate the invention is generally indicated in Figs.
3 and 4.
The shaft of the stick 31 is tapered and sized to fit the geometry of the preform fiber
25 archiliecture such that the desired finished blade thickness is obtained. In this embodiment one
- layer of spun glass rovings 33 is placed on the frontal face of the shaft and the bottom end of
the shaft where it will butt against the core of the preform. A fiber reinforced wooden shaft
could also be used, wherein the fibers are continuous and are oriented substantially parallel to
the length of the shaft. The reinforcing fibers are preformed into pultruded or l~min~t~d sheets
30 or prepregs with resin and are adhesively bonded to the shaft as l~min~tes. Wood l~min~tes are
CA 02228104 1998-01-28
also bonded to the shaft to cover the fiber reinforcements. A preform core about 9 mm thick
in the shape of a hockey stick blade is attached to the shaft by several metal staples 32 on each
side:. The preforrn core 34 in this embodiment is made from, but not restricted to 6 lb per square
foo~: density thermoplastic polyurethane foam. A braided glass sock, or tube 35 open at either
5 end, of approximately 18 cm length, is placed over the preform centered on the puck striking
area, in the middJ.e of the face of the stick. It is constructed of e-glass oriented at +45~ to the
longritudinal axis of the sock 35 and weighs 57 grams per meter and is 4.4 cm in diameter.
Stitched unidirec-tional graphite fiber 46 made of T300, 12 K graphite tow with a yield of 340
grarns per meter is placed over both faces of the blade and curved to run along the shaft to
poin,t 37 where the shaft emerges from the blade preform. A layer of ~45~ T300, 12 K graphite
fabric 48 with a yield of 400 grams per meter is placed over each face of the shaft where it
meets the preforrn to reinforce and strengthen the joint. A spun glass roving 39 of 225 yield
is wrapped around the bottom edge, toe and top edge of the blade and held in place by loops
of polyester thread. A second braided glass sock 40, of identical construction to sock or tube 35,
15 open at either end, of approximately 30 cm length, is placed over the preform and extends from
the toe of the blade to the point 7.
This prefo:rm is saturated with a carefully metered amount of rubber modified toughened
epoxy resin sufficient to fully wet the preform and yield a fiber loading of over 65 % by volume
20 when the skins have been consolidated and cured.
The fiber preform and the shaft up to point 37 are placed into the bottom cavity of a
mold shaped to yield the final morphology of the designed blade. The top half of the mold is
closed and the shaft extends out of the mold and is supported by a fixture to ensure that the
25 required geometrical orientation of the blade and shaft is m~int~ined. Standard compression
molding insert sea.ling techniques are used where the shaft extends from the mold to prevent
resin outflow. The preform and shaft joint assemble are cured at 150~ C and a molding pressure
of between 350 and 800 psi, preferably 600 psi for 5 minutes. The part is removed and flash
from the molding process is trimmed and the required graphics applied.
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Further describing the process, the lower end of the shaft is reduced in section to a
pro~lle suitable for integration within the composite blade component. This profile can consist
of a taper or of a taper termin~ting in a short reduced width section with generally rectangular
shape. A glass roving can be attached to some or all of the faces of the shaft, and the bottom
5 of the shaft, including the lower end face of the shaft. Grooves can be cut, at angles varying
frorn 0~ to 90~ to the longitudinal axis of the shaft, into the surface of the shaft where it will
mate with the blade to improve the interlock of the blade and the shaft. These grooves can be
lightly filled with glass rovings as well. The glass rovings in each case can be tacked in place
by mechanical fasteners, such as staples, by a loop or loops of any suitable thread material or
10 by small spots of hot melt thermoplastic adhesive, methacrylate type adhesive or any other
suitable adhesive. The fastening method, whether adhesive or mechanical, is only used to locate
the r ovings prior to assembly and molding. A core is molded into the outline of a hockey stick
blade and reduced in size to allow for the addition of composite outer skins to form the finished
blade. This core is attached to the lower end of the shaft by mechanical fasteners such as staples.
15 The core can be, but is not restricted to any suitable thermoset or thermoplastic foam, with or
without fiber or particulate reinforcements; any suitable syntactic foam or any type of
honeycomb material where the honeycomb walls are oriented across the narrow dimension of
the core. The fasteners are only used to locate the core of the blade during the subsequent
mamlfacturing steps and do not constitute the mechanism by which the shaft will be bonded to
20 the finished blade. The core is covered with layers of fibrous material such as, but not restricted
to, glass, graphite and aramid. These fibers can be in the form of mat, cloth or rovings. The
reinforcement can be applied in the form of expandable braided or woven socks, or of woven
or stitched fabrics or of rovings. Fabric can be placed in several layers with fibers of the
appropriate type for the loading found in use placed in suitable points of the l~min~t~. For
25 example, the lateral faces central part of the blade can be reinforced with two or more layers
- of glass or other fiber braid to improve the fracture resistance of this area which is used to strike
the puck. One or more layers of unidirectional fibers or fabric, in particular +45~ fabric, can
be used to reinforce the lateral sides at the point at which the shaft touches the core. Fibers,
usual].y in the forrrl of mat or braided socks are wrapped around the entire blade assembly. The
30 amount, type and orientation of fibers are selected to provide the desired weight, stiffness and
11
CA 02228104 1998-01-28
'':
strength of the blade and shaft assembly. One or more glass ropes or rovings can be wrapped
around the perimeter of the blade and held in place by a mechanical fastener, a dab of suitable
adhesive or loops of a suitable thread. When formed into a composite in the final part, this rope
or roving layer will form a wear resistant strip on the bottom of the blade and a curved
:5 cosrnetic finish for the perimeter of the blade.
The blade preform and the lower end of the shaft which is inserted in that preform are
wetted with a suitable resin, such as, but not restricted to, epoxy or a thermoplastic resin such
1() as ]lylon. This preform and the lower end of the shaft are then subjected to carefully controlled
heat and pressure to mold the blade into place integrally around the shaft thereby bonding it
strongly to the shaft. Fixtures locate the blade preform and the shaft to ensure the desired
orientation of the two components as they are formed into the integral stick. The heat and
pressure can be applied by matched die compression molding, resin transfer molding, resin
15 injection molding, vacuum bag processing or other processes. The blade preform can be laterally
curved to any desired curvature typically used by hockey players. If the blade preform is
assembled from thermoplastic core and resin materials, it can be molded into different curvatures
by tlle application of heat and force or pressure subsequent to the initial manufacturing process
for the integral stick.
It follows that this method produces a stick starting from a "bought-in shaft" in which
a total of 6 operations take place. First, the shaping of the end of the shaft takes place, then
followed by the attachment of the rovings to the shaft, and the making of the foam blade
preform. Then tlle preform is attached to the shaft, followed by the molding and finally the
25 trimming of the resulting stick.
The resulting stick has a very strong bond of the shaft to the blade. It will resist
breakage at the shaft to blade joint, which is in this invention a three dimensional unitary joint,
longer than a wood stick under similar usage conditions. It has a higher shaft to blade strength
30 because the blade is integrally bonded to the shaft under conditions of elevated temperature and
12
CA 02228104 1998-01-28
pressure, forming a strong bond where resin penetrates into the wood surface under pressure.
As well, 360~composite reinforcement surrounds all four faces further integrally strengthening
this k:ey hosel area. Micrographic ex~min~tion reveals that the resin penetrates as far as 5 mm
into the wood, integrally joining the wood shaft to the blade.
The stick is manufactured in less than ten minutes, with no requirement for storage while
a&esives dry. It can therefore be produced at a cost which is less than a conventional one piece
all wood stick.
This resulting stick has a shaft stiffness identical to a wood stick with the same shaft, but
the blade is 20% sl:iffer than the comparable wood blade and the stick weighs approximately 25
grams" or 5 % less than a typical wood stick.
Other prefered embodiments may include the use of any other foam or syntactic foam in
15 the core including fiber reinforced foams where the fibers include, in proportions varying from
0 to 100%, but are not restricted to glass, graphite, aramid, boron, alumina, thermoplastics, or
the use of any type of honeycomb in the core, or the use of any fiber architecture, e.g. all
graphite, more graphite, less glass, etc., or the use of thermoplastic resins for the skin of the
blade that will allow post forming of the blade in the shop to reduce stocking requirements for
20 a raLn~re of blade stiffnesses and curvatures, or the use of notches in the end of the shaft with
embeclded glass or other fiber rovings to enhance the bond of the blade to the shaft by forming
a mechanical interlock with composite tongues locking into wood grooves.
The invention may be embodied in other specific forms without departing from the spirit
25 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.
