Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TITLE OF THE INVENTION
Irregular hockey stick shaft and a method of fabrication thereof
FIELD OF THE INVENTION
[0001] The present invention relates to hockey sticks or like-game
sticks. More specifically, the present invention is concerned with hockey
stick
shafts having a cross-section and properties varying along a length thereof.
BACKGROUND OF THE INVENTION
[0002] The art offers a variety of hockey sticks. Typically, hockey
sticks comprise a shaft and a blade. The cross section of the shaft is
traditionally rectangular so as to prevent undesired rotation of the shaft in
the
hands of a player. The cross-sectional dimensions of the hockey stick shaft
are
usually fixed within a narrow range by the requirement that the player must
have a good grip on the shaft.
[0003] It is a common practice to make the shaft with a constant
rectangular geometry from a first extremity thereof to a second extremity
thereof, with a height and a width yielding an ergonomic perimeter standardly
comprised between 90 and 95 mm. The rectangular shape of the shaft allows
assembling either a left or a right blade, and, as mentioned hereinabove,
allows
a resistance to a rotation of the stick in the hands of the player, in direct
relation
to a pressure exerted by the hand of the player.
[0004] The shear gripping force of the hands allows the player to
control the stick in a number of shots, such as the slap shop, the snap shot
and
the wrist shop. Such shots require a controlled rotation of the stick, and are
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therefore dependent on the quality of grip of the gloved hand on the stick.
The
wrist shop for example requires a maximum grip on the shaft for an enhanced
precision. The snap shot is performed very rapidly and also requires a perfect
control of the grip on the shaft of the stick through a movement of the wrists
in
order to generate energy of speed and a satisfactory precision. The slap shot
requires the stick to be rigid, both in flexion and in torsion.
[0005] It has been shown that, when performing a slap shot, first
energy is built up in the stick during a contact between the blade and the ice
or
the ground, before the blade hits the puck, due to a flexion of the shaft.
Then
the energy is released and transferred to the puck upon contacting the blade.
The puck in turn, when contacting the blade, creates a torsion of the shaft,
which resistance to deformation in torsion must be high in order to propel the
puck at a high speed.
[0006] US patent number 6,267,697 and US patent number
5,967,913 to Sulenta describe a hockey stick with a shaft having at least a
portion with a triangular cross section in an attempt to yield an adjustable
grip.
Canadian patent number 2,106,178 to Scherz teaches a hockey stick shaft with
a handle part having at least a bottom surface thereof that is V-shaped to
provide a better grip. However, it is found that although such cross sections
indeed yield a better grip on the shaft by a naked hand, it is not optimized
for a
grip with a gloved hand at a constant gripping force.
[0007] Therefore, in spite of previous efforts, there seems to be
some room for improvement in the art for a new hockey stick shaft combining
an optimized grip and a high rigidity in flexion and in torsion.
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SUMMARY OF THE INVENTION
[0008] There is provided a hockey stick shaft having a proximate
end portion, a central portion and a tapering distal end portion with a blade
mounting part, wherein at least one face of the shaft has at least one polygon
cross section over at least part of a length thereof.
[0009] There is further provided a method for fabricating a hockey
stick shaft having a proximate end portion, a central portion and a tapering
distal end portion with a blade mounting part, comprising the step of
providing
at least one face of the shaft with at least one polygon cross section over at
least part of a length thereof.
[0010] Other objects, advantages and features of the present
invention will become more apparent upon reading of the following non-
restrictive description of embodiments thereof, given by way of example only
with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the appended drawings:
[0012] Figure 1 is a perspective view of a hockey stick shaft
according to a first embodiment of the present invention;
[0013] Figure 2 is a front view of a hockey stick shaft according to
an
embodiment of the present invention;
[0014] Figure 3 is a back view of the hockey stick shaft of Figure 2;
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[0015] Figure 4 is a cross section of the hockey stick shaft of
Figures
2 and 3; and
[0016] Figure 5 is a cross section of the hockey stick shaft of
Figures
2 and 3;
[0017] Figure 6 is a cross section of a hockey stick shaft according
to another embodiment of the present invention; and
[0018] Figure 7 is a cross section of a hockey stick shaft according
to a further embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
[0019] Generally stated, there is provided a hockey stick shaft
having varying cross-section and properties along a length thereof, from a
proximate end portion to a tapering distal end portion thereof.
[0020] As illustrated in the Figure 1 of the appended drawings, a
hockey stick generally comprises a longitudinal shaft 12 provided with a
proximate end portion 14, a central portion 15, a tapering distal end portion
16,
and a blade (not shown) mounted to the distal end portion 16.
[0021] The present invention is mainly concerned with the
longitudinal shaft 12, so that the other parts of the stick will not be
described in
detail herein, since they are believed well known to people skilled in the
art.
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[0022] Each parts of the hockey stick have different
functions and
are submitted to specific applied forces, and that the hands of the player are
not located on a same edge of the shaft simultaneously. For example, the
proximate end portion 14 provides for a grip by a first hand of a player and
the
central portion 15 generally provides a grip for a second hand of the player.
The portion comprised between the two hands of the player acts as a spring
that stocks and releases energy. The grip on the shaft may also depend in part
on the gloves the player wears. Gloves are usually made of a relatively stiff
material such as leather, and, when the gloved hands grip the shaft, the glove
form creases due to a thickness thereof. Moreover, depending of the wetness
of the material they are made of, their slippering characteristics vary.
[0023] Various embodiments of the shaft of the present
invention will
now be described.
[0024] In Figure 1, the shaft 12 is an elongated member with
a cross
section in the proximate end portion 14 and in the central portion 15 being a
symmetric or asymmetric polygon, with 6 faces for example, the circumference
all over the length of the shaft 12, from the proximate end portion 14 up to
the
distal end portion 16, which has a rectangular cross section for mounting the
blade (not shown), being constant and similar to the standard circumference of
rectangular cross section hokey shafts known in the art.
[0025] The polygon cross section provides an increased number
of
edges along the length of the shaft, which is found to yield an enhanced grip
thereon by gloved hands.
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[0026] Moreover, as shown in Figures 2 to 5, the polygon cross-
section may be varied along the length of the shaft, depending on the
requirement of the different parts thereof as described hereinabove.
[0027] Figure 2 shows a front surface of a shaft according to an
embodiment of the present invention, and Figure 3 shows its back surface.
[0028] In the back surface shown in Figure 3, the proximate end
portion 34 has a first polygon cross section, shown in Figure 5, and a region
between the central portion 35 and the distal end portion 35 has a second
cross section rotated by 180 degrees in relation to the first cross section as
shown in Figure 5. People in the art will appreciate that such an inversion
allows for the inverted position of the hands of the player.
[0029] Although in Figure 2, the front surface is symmetrical to the
back surface of Figure 3, it may be contemplated providing asymmetric front
and back surfaces.
[0030] The cross section may be linearly inverted from a front face to
a back face of the shaft, along the length thereof, in order to increase
mechanical resistance in torsion and flexion, as shown in Figures 2 and 3.
[0031] As further illustrated in Figures 6 and 7, the polygonal cross
section may be selected as having a left or a right orientation.
[0032] It is found that the polygon cross section yields a surface
moment of inertia superior to that achieved by a rectangular cross section of
a
same circumference for a given width and thickness of the walls of the shaft.
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The polygon cross section consequently causes an increased localized
stiffness of the shaft, while maintaining the weight and circumference of the
shaft.
[0033] The polygon cross section may be provided on target parts of
the length of the shaft. A polygon cross section in the first half part of the
shaft
from the proximate end portion is for example inverted by 180 degrees in the
second half part thereof, providing a cross-over region, extending over a
varying length of the shaft, of increased moment of inertia and therefore of
increased stiffness, in the intermediate region of the shaft.
[0034] Therefore, according to a second aspect of the present
invention, there is provided a method for fabricating a hockey stick shaft
comprising the step of providing at least one face of the shaft with at least
one
polygon cross section over at least part of a length thereof.
[0035] It is further contemplated providing high tensile strength
wires
on at least longitudinal parts of at least one plane surface of the shafts 12
longitudinally oriented inside a thickness of the walls thereof in cases of
hollow
shafts for example, as a way to increase a toughness in flexion (higher
rigidity)
thereof at a relatively constant weight.
[0036] When wires are provided on the shaft in opposite surfaces,
which are submitted to tension and compression forces generated by the
flexion of the shaft, they provide a reinforcing system able to limit an
amplitude
of deformation of the shaft. Due to a high tensile strength and to a high
modulus of elasticity thereof, the wires therefore make the shaft tougher and
even more resistant in flexion, with a minimized increase of weight.
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[0037] The wires are typically metallic (including non-ferrous) wires,
and made in aluminum, brass or steel for example, as required by performance
and process criteria including the weight of the shaft, and the way the wires
are
provided into the material of the shaft, for example. The wires may further be
in
organic or inorganic material. Alternatively, organic or inorganic fibers, in
the
form of integral molded rovings or of premolded cables added during molding,
may be provided on at least longitudinal parts of at least one plane surface
of
the shafts 12 longitudinally oriented inside a thickness of the walls of the
hollow
shaft, as a way to increase a toughness in flexion (higher rigidity) thereof
at a
relatively constant weight.
[0038] In the case of a laminated composite shaft, an optimized
quality of bonding between the wires and a resin matrix of the laminated
composite may be achieved by using brass electroplated steel wires, twisted
wires or a wire mesh for example. The wires may be encapsulated, embedded
or mechanically incorporated into the material of the selected surface(s) of
the
shaft.
[0039] It is to be noted that wires extending along the length of the
shaft may further hold broken pieces of the shaft together in the event of a
transverse sectional breakage thereof for example. Since they are
encapsulated, embedded or mechanically incorporated into the material of at
least one surface of the shaft and due to their high tensile strength, the
wires
indeed maintain a structural integrity even upon total breakage of the section
of
shaft, thereby preventing the broken pieces, which generally have cutting
edges, to be separated apart. Thus, risks of injuries due to exposed cutting
edges of the broken pieces are reduced.
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[0040] The shafts of the present invention may be a hollow
laminated or a hollow wood shaft for example.
[0041] People in the art will appreciate that the hockey stick shafts
according to the present invention meet standard requirements of the art,
including an ergonomic circumference, rigidity, weight, and adequate position
of a center of gravity thereof.
[0042] Moreover, the hockey stick shafts according to the present
invention allow an optimized quality of the grip by the gloved hands of the
player, for example by providing an increased resistance to slipping during a
rotational movement of the gloved hand of the player about the shafts, as well
as an increased rigidity and enhanced safety features if desired.
[0043] Although the present invention has been described
hereinabove by way of embodiments thereof, it can be modified, without
departing from the teachings thereof as described herein.
