Patent Application
20090172974
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.
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 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 inwardly. This is undesirable, since walking with snowshoes having a frame which flexes during gait is difficult.
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:
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 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.
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 frame 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.
In the annexed drawings
Frame member 12 is U-shaped in the embodiment shown in
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
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 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, 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 10b 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
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 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
It can be seen in
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
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 is members 24f and be compacted underneath upwardly-oriented tongue members 24e. When the user leans against his snowshoe 10 to 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, 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
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.
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.
Frame member 102 could be made from any suitable material, but in the example shown in
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, 102f.
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
