Note: Descriptions are shown in the official language in which they were submitted.
CA 02617453 2008-01-08
TITLE OF THE INVENTION: SNOWSHOE
FIELD OF THE INVENTION
The present invention relates to snowshoes and more particularly to a snowshoe
having a decking which increases the grip of the snowshoe over snow and the
overall rigidity of the
snowshoe.
BACKGROUND OF THE INVENTION
Some snowshoes include a semi-rigid decking linked to a peripheral frame by
means
of attachments in the form of tongue members extending from a central, load-
bearing portion of the
decking to the peripheral frame of the snowshoe. These tongue members usually
all extend either
io over the frame or under it. In all cases, the tongue members will pull on
the frame side bars when
the decking is loaded by a person's foot, forcing the frame side bars
inwardlv. This is undesirable,
since walking with snowshoes having a frame which flexes during gait is
difficult.
SUMMARY OF THE INVENTION
The present invention relates to a snowshoe defining opposite front and rear
ends,
opposite first and second sides and opposite top and bottom surfaces and
comprising:
- a rigid peripheral frame member comprising a top portion corresponding to
said top
surface of said snowshoe and a bottom portion corresponding to said bottom
surface of
said snowshoe and having a frame member thickness defined between said top and
bottom portions;
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- a decking that is at least semi-rigid and that comprises a central load-
bearing portion
and a number of tongue members fixed to said load-bearing portion and attached
to said
frame member whereby said frame member carries said decking; and
- a harness pivotally attached to either one of said decking and said frame
member for
allowing a person's foot to be releasably attached to said snowshoe;
wherein said tongue members have a staggered attachment configuration relative
to the
thickness of said frame member.
In one embodiment, said frame member is U-shaped and comprises first and
second
elongated generally parallel side bars respectively located on said snowshoe
first and second sides
io and integrally linked by an arcuate front frame tip portion, said frame
member defining a gap near
said rear end of said snowshoe between said first and second side bars, said
decking defining a free
rear edge which is not attached to said frame member at said read end of said
snowshoe.
In one embodiment, said decking comprises a toe hole for allowing the person's
foot
attached to the snowshoe with said harness to extend cyclically under and over
said decking by
pivoting into and out of said toe hole during gait.
In one embodiment, said harness is pivotally attached to said decking on a toe
hole
edge portion thereof.
In one embodiment, at least some of said tongue members are spaced-apart
tangentially along said frame member and openings are consequently defined
between said at least
some spaced-apart tongue members.
In one embodiment, a number of said tongue members extend from said load-
bearing
portion towards said frame member top portion while a number of other said
tongue members
extend from said load-bearing portion towards said frame member bottom
portion.
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In one embodiment, at least some groups of consecutive tongue members include
tongue members that extend alternately towards said top and said bottom
portions of said frame
member.
In one embodiment, said frame member is made of aluminium.
In one embodiment, a number of said tongue members extend from said load-
bearing
portion into slots made through said frame member between said top and bottom
portions thereof.
In one embodiment, a number of other tongue members than those that extend
into
said slots extend towards said bottom portion of said frame member.
In one embodiment, at least some groups of consecutive tongue members include
tongue members that extend alternately into said slots and towards said bottom
portion of said franie
member.
In one embodiment, said frame member is made of wood.
In one embodiment, said decking is unitary and said tongue members are
integrally
fixed to said load-bearing portion.
ls DESCRIPTION OF THE DRAWINGS
In the annexed drawings:
Figure 1 is a top perspective view of a snowshoe according to one embodiment
of the
present invention;
Figures 2 and 3 are cross-sectional elevations respectively taken along lines
II-II and
I11-I1I of figure 1;
Figure 4 is a top perspective view of a snowshoe according to another
embodiment of
the present invention; and
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Figures 5 and 6 are cross-sectional elevations respectively taken along lines
V-V and
VI-VI of figure 4.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Figures 1-3 show a snowshoe 10 according to one embodiment of the present
invention. Snowshoe 10 defines opposite front and rear ends 10a, 10b, opposite
first and second
sides lOc, 10d and opposite top and bottom surfaces 10e, 10 Snowshoe 10
comprises a rigid
peripheral frame member 12 comprising a top portion 12e corresponding to top
surface 10e of
snowshoe 10 and a bottom portion 12f corresponding to bottom surface l Of of
snowshoe 10.
Frame member 12 is U-shaped in the embodiment shown in figures 1-3 and is made
from a bent aluminium tube, although it is understood that frame member 12
could be made in other
shapes and from other materials, as will be further exemplified hereinafter.
In the embodiment of
figure 1-3, frame member 12 comprises first and second elongated generally
parallel side bars 14, 16
respectively located on the snowshoe first and second sides 10c, 10d and
integrally linked by an
arcuate front frame tip portion 12a. Frame member 12 defines a gap near the
rear end 10b of
snowshoe 10 between first and second side bars 14, 16 in that no transverse
rear frame bar is
provided.
Frame member 12 has a thickness defined between its top and bottom portions
12e,
12f. This thickness is constant and equal to the diameter of the tube used to
form frame member 12
in the embodiment of figures 1-3, but it is understood that this thickness
could alternately vary along
the length of frame member 12 if it had an irregular shape.
Snowshoe 10 further comprises a decking 20 that comprises a central load-
bearing
portion 22 and a number of tongue members 24e, 24f that will be collectively
referred to as tongue
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members 24. Tongue members 24 are fixed to load-bearing portion 22 at a first
extremity and
attached to frame member 12 at another extremity. More particularly, decking
20 is unitary and
consequently tongue members 24 integrally extend from load-bearing portion 22.
Tongue members
may be attached to frame member 12 in any suitable manner, for example with
pins, bolts, tie wraps,
5 strings, screws, rivets, glue or any other suitable attachment means,
whereby frame member 12
carries decking 20. Decking 20 defines a free rear edge 20b which is not
attached to frame member
12 at the read end l Ob of snowshoe 10.
Decking 20 is at least semi-rigid, in that it cannot be made entirely flexible
but it
could be semi-rigid or rigid. Semi-rigid deckings are usually preferable since
it is usually desirable
to have the decking yield and flex slightly under a person's load during use,
but the rigidity of the
decking is a design choice that might result in a more rigid decking being
used. In any event,
considering that decking 20 is relatively thin, and desirably so, it is likely
to at least slightly flex
under a person's weight whatever the material used. For example, semi-rigid
plastic may be used for
decking 20.
A harness 26 is attached to either one of decking 20 and frame member 12 for
allowing a person's foot to be releasably attached to snowshoe 10. More
particularly, in the
embodiment of figures 1-3, decking 20 comprises a toe hole 28 for allowing the
person's foot
attached to the snowshoe with harness 26 to extend cyclically under and over
decking 20 by
pivoting into and out of toe hole 28 during gait, as known in the art. Harness
26 is consequently
pivotally attached to decking 20 on a toe hole edge portion thereof. Harness
26 conventionally
comprises a rigid toe plate 30 pivotally carried by decking 20 and on which
the foot will rest. Toe
plate is bent to form a claw plate 32 at its extremity that protrudes in toe
hole 28. A buckle assemblv
34 comprising front buckles and a heel buckle allows the user's foot to be
releasably attached to
harness 26. A rigid or semi-rigid front toe guard 3 6 protects the user's
toes.
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Snowshoe 10 further conventionally comprises a toothed heel gripping member 38
fixed underneath decking 20.
According to the present invention, it can be noted that tongue members 24
have a
staggered attachment configuration relative to the thickness of frame member
12. That is to say that
tongue members are offset relative to one another along an axis which is
generally perpendicular to
decking 20.
More particularly, is will be noted that a number of tongue members 24e extend
from
the decking load-bearing portion 22 in a slightly upward direction towards the
frame member top
portion 12e while a number of other tongue members 24f extend from the decking
load-bearing
io portion 22 slightly downward towards the frame member bottom portion 12f.
By thus orienting
tongue members 24e and 24f respectively upwardly over frame member 12 and
downwardly under
frame member 12, the above-mentioned staggered configuration is obtained,
relative to the thickness
of frame member 12. It will be noted that although the upwardly-oriented
tongue members 24e in
the embodiment shown in figures 1-3 are also attached on the frame member top
portion 12e, they
could alternately extend upwardly over frame member 12, be partly wrapped
around frame member
12 and be attached to the frame member bottom portion 12f. The key element is
their orientation as
they extend from decking 20 and not necessarily where they are attached. The
same is true for the
downwardly-oriented tongue members 24f: they could extend downwardly, be
partly wrapped
around frame member 12 and be attached to its top portion 12e.
It can be seen in figures 1-3 that at least some groups of consecutive tongue
members
24 include tongue members 24e, 24f that extend alternately towards the top and
bottom portions
12e, 12f of frame member 12. For example, this alternation can be seen along
almost the entire
length in the embodiment of figures 1-3 where, along each one of side bars 14
and 16, the rearmost
tongue member 24 is an upwardly-oriented tongue member 24e; the frontwardly
adjacent tongue
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member 24 is a downwardly-oriented tongue member 24f; the next tongue member
24 is an
upwardly-oriented tongue member 24e; the following one, a downwardly-oriented
tongue member
24f; and so on. This alternation is repeated up to and excluding the frontmost
tongue member 24
which is an upwardly-oriented tongue member 24e which follows another upwardly-
oriented tongue
member 24e.
This feature of the tongue member orientation alternation is optional, but
provides
interesting properties to snowshoe 10 as will be detailed hereinafter.
Snowshoe 10 could indeed be
provided with series of adjacent upwardly-oriented tongue members 24e and
series of adjacent
downwardly-oriented tongue members 24f in a regular or irregular array without
departing from the
scope of the present invention. Since both the downwardly-oriented and the
upwardly-oriented
tongue members 24f and 24e would still be provided and consequently the tongue
members 24
would still be misaligned, they would still be considered to present a
staggered configuration.
In the embodiment shown in figures 1-3, tongue members 24 are spaced-apart
tangentially along frame member 12 and openings 40 are consequently defined
between the spaced-
i5 apart tongue members 24. It is noted that none or only some of the tongue
members 24 could be
spaced-apart.
Other central openings 42 can optionally be provided on decking 20.
The staggered configuration of tongue members 24 provides at least two
important
advantages to snowshoe 10.
Firstly, snowshoe 10 has an enhanced grip on the snow when snowshoe 10 rests
on
the ground. Indeed, as snowshoe 10 is applied on the ground and especially
when snowshoe 10 is
loaded with a person's weight, it will at least slightly sink in the snow and
consequently some snow
will be located between consecutive downwardly-oriented tongue members 24f and
be compacted
underneath upwardly-oriented tongue members 24e. When the user leans against
his snowshoe 10 to
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move forward during a step, he will in fact push back against the snowshoe.
The downwardly-
oriented tongue members 24f will then abut with their edges against the snow
located rearwardly of
tongue members 24f to increase the gripping effect of the snowshoe 10. Thus,
the staggered
configuration of tongue members 24 will contribute to help prevent sliding of
the snowshoe on the
snow in combination with other known structures that have this purpose such as
the heel gripping
member 38 and the toe plate claw 32.
However helpful in increasing the gripping effect of snowshoe 10 the staggered
configuration of tongue members 24 may be, it will not hinder the snowshoe
when it is carried
frontwardly by the foot during the forward movement thereof during a step.
This is due to the fact
that the snowshoe will be lifted above ground during that portion of the step
and, alike the toothed
heel gripping member 38 and the toe plate claw 32, the tongue members 24 will
not slide along the
ground but rather be carried spacedly over it.
Secondly, a very unexpected and advantageous result stems from the staggered
configuration of tongue members 24: the rigidity of the entire snowshoe 10 is
increased. Indeed,
under a person's load, the upwardly-oriented tongue members 24e will be
tensioned while the
downwardly-oriented tongue members 24f will be compressed. This is due to the
semi-rigid nature
of decking 20 and to the staggered configuration of tongue members 24 which
will incur outwardly-
oriented forces in the downwardly-oriented tongue members 24f and inwardly-
oriented forces in the
upwardly-oriented tongue members 24e. The outward force exerted by the
downwardly-oriented
tongue members 24f will help maintain the frame side bars 14, 16 in position,
i.e. will help prevent
side bars 14, 16 from undesirably flexing inwardly. This consequently helps
prevent frame 12 from
flexing during gait, which is a highly desirable result.
This is contrary to prior art deckings where all the tongue members or decking
attachments are usually upwardly-oriented (or, more generally, all oriented in
a same direction.
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instead of having a staggered configuration): in such a case, all tongue
members would be forced
inwardly under load, resulting in the frame side bars being undesirably forced
inwardly each time
the user's weight is applied on the decking. This means that the prior art
frames often flex in and out
during gait, which makes walking much more difficult; or, in the alternative,
much more rigid
frames are required, making the snowshoe heavier, bulkier and more expensive.
This unexpected advantage of the snowshoe rigidity being increased is highly
interesting for all kinds of snowshoes, but moreso for snowshoes of the type
that have an opened-
ended peripheral frame 12 such as the one shown in the embodiment of figures 1-
3. Indeed, by
providing snowshoe 10 with a frame having a gap at the read end of frame
member 12, the overall
io rigidity of frame member 12 is decreased, ceteris paribus. However, this
gap is advantageous in that
it decreases the friction or drag effect of the snowshoe during gait. It also
allows snow to be
unloaded more easily from decking 20 by sliding off decking 20 towards the
rear end lOb of
snowshoe 10. It is recalled that a snowshoe will be lifted over ground when
the foot is moved
forward during a step, but that the rear tail 10b of the snowshoe will drag
along the ground during
that time. Indeed, the front tip 10a of the snowshoe must desirably be tilted
upwardly to prevent it
from diving into the snow or otherwise sliding underneath a tree branch or
other ground obstacle,
which results in its tail end 10b dragging along the ground. Having a
transverse frame portion at the
snowshoe tail end l Ob increases the friction of the snowshoe significantly.
As a result, having the staggered configuration of tongue members 24 will in
fact
mitigate the trade-off that would otherwise have been made: the rigidity of
frame member 12 will be
significant while still having a frame member 12 devoid of any rear transverse
bar and having
reasonable dimensions and weight.
Figures 4-6 show a second embodiment of a snowshoe 100 according to the
present
invention. Snowshoe 100 is similar to snowshoe 10, except as detailed
hereinafter.
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Snowshoe 100 comprises a generally U-shaped peripheral frame member 102 having
an opened rear end and carrying a decking 104 that is at least semi-rigid.
Decking 104 comprises a
central load-bearing portion 106 and a number of tongue members 108a, 108b
that will be
collectively referred to as tongue members 108.
5 Frame member 102 could be made from any suitable material, but in the
example
shown in figures 4-6, frame member 102 is made of wood.
Frame member is pierced to form a number of slots 110 that extend through
frame
member 102 from an inner side thereof 102g to an outer side thereof 102h,
between the frame
member top and bottom portions 102e, 102
10 Tongue members 108 include a number of tongue members 108a that extend from
the
decking load-bearing portion 106 into slots 110 and a number of other tongue
members 108b than
those that extend into slots 110 that extend towards the bottom portion 102f
of frame member 102.
Tongue members 108a are fixed inside slots 110.
The embodiment of figures 4-6 consequently shows another type of staggered
configuration of tongue members 108 which still provides the desired
advantages detailed
hereinabove.
