1. Field of the Invention
The invention relates to the field of cross-country skiing.
2. Description of Background and Relevant Information
For a long time, cross-country skis have been used with rudimentary devices for binding the boot to the ski. The boot sole had, for example, a tongue or a binding strap extending beyond the front end of the boot and which was held in a lock arranged forward from the position of the boot in relation to the ski.
It has been realized that this type of binding had two major drawbacks. During the practice of the conventional alternate step technique, it was noticed that these systems necessitated a forward rotational movement of the boot in relation to the ski which was located far ahead of the foot. The result was a movement of the foot that was not natural, far from the foot rolling movement that can be observed when walking. During the practice of the skating step, these systems also had the drawback of providing only a very poor lateral guidance of the boot in relation to the ski.
In order to remedy these problems, systems for binding the boot to the ski, whereby the boot was articulated on the ski about an axis arranged immediately behind the front end of the sole, were introduced in the 1980s. These systems had at least part of the binding device arranged under the boot sole. This enabled the boot pivot point to be moved back in relation to the ski and to rigidify the torsional strength of the boot/binding assembly during the practice of the skating step.
The device described in the document FR-2.739.788 shows that the articulation axis of the boot as well as the elastic return means, which tend to apply the boot flat against the ski, are located under the sole.
Other devices, which are described, for example, in the documents FR-2.742.060, FR-2.782.652, WO-01/93963, WO-02/05907, or WO-02/087710, confirm that the trend is to seek a positioning of the binding device that is as much under the boot sole as possible, and no longer mainly at the front of the boot.
However, many of these systems have the drawback of being positioned between the boot and the ski, and of particularly raising the boot in relation to the ski. The primary consequence of this is not allowing for a direct support of the boot on the ski, which can negatively affect a proper support on the ski edges, especially for the practice of the skating step. In addition, in the known systems, the support of the boot on the ski does not occur directly on the ski, but rather generally by means of a baseplate which covers more or less the entire width of the ski upper surface, such as shown, for example, in the document EP-878.218. The presence of such a baseplate increases the height of the boot position and has a tendency to also distribute the pressure over the width of the ski whereas, during edge setting, one wishes instead to concentrate a maximum of the ski pressure on one of the edges, typically the inner edge.
An object of the invention is therefore to provide a cross-country ski which provides for better transmission of forces on the ski edges, as well as optimal stability.
To this end, the invention provides a cross-country ski having a binding zone adapted to receive a device for binding a boot to a ski, wherein the binding zone includes a location for receiving the binding device, and an upper support surface of the ski that is arranged on at least one side of the location for receiving the binding device and on which the boot can possibly come in direct contact when the user applies a pressure force.
Other characteristics and advantages of the invention will appear from the detailed description that follows, with referenced to the annexed drawings, in which:
The binding device 12 is, for example, similar to that described in the document FR-2.739.788 and family member U.S. Pat. No. 6,017,050, which will be referred to for a detailed description. This device includes a front jaw 16 in which a front bar 18 of the boot 14 is adapted to be locked to enable the attachment of the boot to the ski by means of articulation about the transverse axis of the bar. For this purpose, this binding device 12 enables the boot heel to be lifted from the ski. The device 12 also includes longitudinally, at the rear of the jaw 16, an elastic return mechanism that includes an articulated connecting rod 20 adapted, for example, to hook a rear bar (not shown) arranged under the sole 22 of the boot 14. Finally, in the rear extension of the connecting rod, the binding device 12 also includes a guiding edge 24, or rib, the profile of which is complementary to a corresponding groove (not shown) formed under the boot sole.
According to the invention, the arrangement of the binding device 12 on the ski 10 is such that it is arranged transversely on both sides of the position of the binding device 12, of the portions of the upper surface 26 of the ski that form support surfaces 28 which corresponding support surfaces 30 of the boot sole are adapted to contact directly.
The invention encompasses several alternative embodiments.
With respect to a ski having a planar, or flat, upper surface, the shoulders can be made in the form of elevated bosses, or they can result from a recess in the central portion of the ski, this recess thus defining the location of the ski binding device.
This embodiment allows achieving a lower position for the binding, and therefore a lower position of the boot with respect to the snow, which can favorably affect the stability of the system.
Contrary to the embodiment shown in
In the example shown in
In both cases, one can see in
The binding device 12 shown in the drawings is a simple embodiment, and the invention can be implemented with other types of binding devices adapted for the practice of cross-country skiing. The invention also encompasses the binding device being partly integrated into the ski, for example with an element that is articulated directly in the ski, or with part of the guiding edge integrated into the ski. However, the invention provides that, at least in the area of the support zone, the binding device is narrower than the ski. These support zones are preferably longitudinally arranged in an area corresponding to the metatarsophalangeal bending zone of the user's foot, which is the preferred zone through which the user exerts his support force at the end of the thrust, when his heel is already raised with respect to the ski.
Similarly, the examples show the case where two support surfaces are provided on respective sides of the binding. However, taking into account that the forces are mostly important on the side of the ski inner edge, during the practice of the skating step, one can provide that the ski include only one direct support lateral surface, arranged on only one side of the binding device.
Preferably, the lateral support surfaces 28 of the ski are substantially horizontal, meaning that they are substantially parallel to the lower gliding surface of the ski.
However, in the example of embodiment shown in FIGS. 5 to 7, it can be provided that the lateral support surfaces 28, instead of being flat or planar, a curvature complementary to a curvature of the lower surface 30 of the boot sole.
Similarly, as can be seen in
Number | Date | Country | Kind |
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03/10443 | Sep 2003 | FR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/FR04/02216 | 9/1/2004 | WO | 6/28/2006 |