Patent Application
20080290621
The present invention relates to an alpine snowboard.
Alpine snowboards do not all have the same behavior on snow. For example, some are well adapted to practice in powder snow, while others are recommended in the case of use on hard-pack or even icy snow. In the same order of ideas, certain alpine snowboards are designed to have high qualities in terms of turning behavior, whereas other snowboards are expected to be highly maneuverable in varied circumstances, for example in bumpy terrain.
Each snowboard has a set of structural and dimensional features which determine its behavior on snow and which are selected according to the type of practice for which the snowboard is ideally intended.
An example of such a feature is found in document EP-1 264 618, which proposes to have two symmetrical cutouts in the top portion of a snowboard so that, at the location of these cutouts, the snowboard has a local deformation zone where its bending and/or twist stiffness is lower.
The content of document DE-100 03 345 also constitutes an attempt to modify the behavior of a snowboard. More precisely, this document proposes to improve the sliding behavior of a snowboard, in terms of a lower sensitivity to uneven ground, by conforming the longitudinal sides of the snowboard so that, in a turn, the contact of one of these sides with the snow is limited on the whole to only three zones longitudinally offset from one another.
Like those discussed above, numerous solutions aimed to improve and/or modify the behavior of the snowboard on snow have already been proposed.
However, it can be estimated that it is still possible to meet certain needs of skiers better, particularly beginning skiers.
To this end, it is the object of the invention to confer on a ski a novel behavior on snow, more particularly adapted to practice at beginner level.
According to the invention, this object is achieved with an alpine snowboard, comprising a boot portion having elements of a binding, a tail portion located at the back of said snowboard and extending along about 1/10 of the total length of said snowboard, and a back intermediate portion located between the boot portion and the tail portion, part of which is a zone having reduced mechanical properties, said snowboard having a base and first and second squares each extending on one side of the said base, from the front of the snowboard to a back end of said snowboard, characterized
A snowboard as defined above facilitates the execution of turns particularly for a beginner. Its front part acts effectively in the first phase of a turn, that is upon the entry into a turn, while its back part facilitates the exit from said turn, if need be by initiating a side-slip.
Preferably, said cutout extends along the whole height of the snowboard.
Another advantageous feature of the snowboard may be that it comprises a spatulate portion and a front intermediate portion which is located between the boot portion and the spatulate portion, only the back intermediate portion among the back and front intermediate portions comprising a zone having reduced mechanical properties which is the result of at least one lateral cutout located at least on the lower part of the snowboard and in which the first square at least has a deviation so as to comprise two square portions movable vertically with regard to each other.
Advantageously, the zone having reduced mechanical properties is also the result of another lateral cutout located at least on the lower part of the snowboard, one and the other cutout being located respectively on a first side and a second opposite side of the snowboard, the second square having a deviation at the location of said other cutout so as to comprise two square portions movable vertically with regard to each other, that is a back square portion and a front square portion which are separated by said deviation. When this is the case, the particular behavior of the snowboard is observable both in the case of a left turn and in the case of a right turn.
Preferably, at the location of said zone having reduced mechanical properties, the snowboard comprises additional stiffening means tending to increase the bending stiffness of the snowboard in a longitudinal plane at least. These stiffening means may comprise a thickening of the snowboard at the location of said zone having reduced mechanical properties. Thanks to such means, it is possible to compensate for all or part of the bending stiffness in a longitudinal plane of the snowboard due to the presence of the cutout or cutouts.
Said zone having reduced mechanical properties is located in front of a back contact line of the snowboard.
Advantageously, the zone having reduced mechanical properties is a zone having a lower twist stiffness.
The invention will be better understood from a reading of the description that follows, provided exclusively as an example and with reference to the appended drawings, in which:
In the following description and in the appended claims, the terms “back”, “front” and “lateral”, and similar terms, refer to the direction of movement of the snowboard sliding on snow during normal use.
On the major part of its length, the underside of the unloaded snowboard 1 has a downward concavity, commonly called “camber”.
On the back, the snowboard 1 is upturned from a back contact line 2. On the front, it is upturned from a front contact line 3. In the context of the present invention, and according to the definition given by standard ISO 6289-1985, the back contact line 2 and the front contact line 3 are respectively the back limit of the contact zone of the underside of the ski on a flat surface and the front limit of the contact zone of the underside of the ski on a flat surface, the ski being applied to said surface, that is loaded so as not to have the abovementioned camber.
The snowboard 1 comprises two portions located opposite one another, that is a tail portion 4 and a spatulate portion 5. The tail portion 4 extends along about 1/10 of the total length L of the snowboard 1, from the back end 6 of said snowboard 1. In certain cases, it may extend along only 9% of the total length L.
Between the tail portion 4 and the spatulate portion 5 are three other portions of the snowboard 1 in succession, that is a back intermediate portion 8, a boot portion 9 and a front intermediate portion 10. The back intermediate portion 8 connects the tail portion 4 to the boot portion 9, which the front intermediate portion 10 connects to the spatulate portion 5. The boot portion 9 is the portion where an adapted binding is attached to rigidly join a snowboard boot to the snowboard 1, in a manner known per se. In
As may be seen in
The back intermediate portion 8 comprises a zone having reduced mechanical properties 19. In the context of the present invention, a zone having reduced mechanical properties is a zone in which the twist stiffness, the bending stiffness and/or other mechanical properties of the snowboard 1 are lower than on either side of said zone, varying abruptly along a few centimeters or even a few millimeters in the longitudinal direction X-X′. Symmetrical on the whole about a vertical and longitudinal plane P, the zone 19 is offset frontward from the back contact line 2. Preferably, it is precisely a zone having a lower twist stiffness, that is a zone in which the twist stiffness of snowboard 1 about its longitudinal axis X-X′ is lower than on either side of the said zone. The lower twist stiffness of the snowboard 1 at this zone 19 is the result of a narrowing at said zone 19, in which each side of the snowboard 1 bounds an outwardly directed lateral cutout 20.
Each cutout 20 terminates downward and upward. In other words, each cutout 20 extends along the whole height of the snowboard 1 and particularly on the lower part of said snowboard. At this lower part, each cutout 20 is bounded by one of the squares 14 and 15. For this purpose, each square 14 or 15 is bent several times in order to have an inward deviation 21, at the zone 19. Each deviation 21 skirts a cutout 20.
Each cutout 20 has a length D which is advantageously between 6% and 17% of the length L of the snowboard 1, and preferably between 11% and 12% of said length L and/or between 150 mm and 200 mm.
Each cutout 20 has a depth p which is advantageously between 0.2% and 2% of the length L of the snowboard 1, and preferably between 0.4% and 0.5% of said length L. Although it can reach several centimeters, the depth p is preferably between 4 mm and 10 mm.
The deviation 21 of a square 14 or 15 connects two portions of said square together, that is a back square portion 22 and a front square portion 23 which are vertically movable with regard to each other in case of twisting T about the longitudinal axis X-X′, symbolized by the arrow D in
The back portions 22 extend along the tail portion 4 and on either side of the back contact line 2, which they cross. They are therefore located in one of the regions where the pressure of a square 14 or 15 on the snow is the highest when the skier executes a turn. In other words, a sufficiently long portion subsists behind the zone 19 to act effectively to “dig in” when executing a turn on snow.
The presence of the deviations 21 at the discontinuity zone 19 confers a novel behavior on the snowboard 1, which is characterized by a greater aptitude for side-slip. A snowboard having such an aptitude is particularly appropriate for beginners.
At the zone 19, the narrowing of the snowboard 1 results in little or no reduction of the bending stiffness of said snowboard 1 at least in the longitudinal and vertical plane P. This results from the presence of additional stiffening means which, in the example described, have the form of a local thickening 24 of the snowboard 1 at the zone 19. This thickening is advantageously lower than 15% of the thickness of the snowboard 1 just behind the zone 19. Preferably, it is between 2% and 10% of the thickness of the snowboard 1 just behind the zone 19.
The invention is not limited to the embodiment described above. In particular, the cutouts 20 may not pass completely through the snowboard 1 and may be located only in the lower part of said snowboard 1.
Furthermore, the two cutouts 20 may not be symmetrical to one another. The snowboard 1 may even have only a single cutout at its zone 19. In the case of an asymmetry, one of the cutouts 20 may be offset from the other cutout 20 along the snowboard so that, on snow, the inner square behaves differently from the outer square which does not play the same role as the inner square in a turn. When this is the case, it becomes possible to switch the left and right skis to benefit from a novel behavior on snow.
Furthermore, at least one of the deviations 21 may be replaced by a continuous solution where the corresponding square is interrupted. However, the configuration in which each square is made of a single piece and comprises a deviation skirting a cutout has the advantage of being rugged and economical.
Moreover, additional stiffening means other than the local thickening 24 of the snowboard 1 may be provided at the zone 19 in order to increase the bending stiffness of the snowboard at said zone in a longitudinal plane at least. For example, these additional stiffening means may comprise one or more additional reinforcements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 0755277 | May 2007 | FR | national |
