US20030122349A1

US20030122349A1 - Cross-country ski

Info

Publication number: US20030122349A1
Application number: US10/314,570
Authority: US
Inventors: Christian Paillot
Original assignee: Skis Rossignol SA
Current assignee: Skis Rossignol SA
Priority date: 2001-12-27
Filing date: 2002-12-09
Publication date: 2003-07-03
Also published as: FR2834221B1; EP1323455A1; FR2834221A1

Abstract

Cross-country ski (1) having a tip (4) curved upward, extending beyond the front contact line (2), wherein the projection of the side line of the tip (4) of the ski over a horizontal plane has an inflexion point (6, 7) located forward of the front contact line (2), at least on one side of the ski.

Description

TECHNICAL FIELD

The invention relates to the field of gliding sports and, more particularly, to that of cross-country skiing. More precisely, it relates to a cross-country ski having a tip that is optimized and, more precisely, “narrowed” in comparison to conventional cross-country skis.

Prior Art

In a known manner, a cross-country ski has a front end forming a tip. This tip forms an upwardly curved zone, the width of which decreases toward its end. This tip is curved upward to enable the ski to be on top of the snow and to overcome obstacles and differences in level that exist on the gliding trail.

Generally speaking, this tip is considered to start forward of a transverse line defined in standard fashion as the front contact line.

In cross-country skiing specifically, using the skating technique, the skier performs a movement in which the bearing forces are taken up while the ski is oriented obliquely relative to the direction of displacement.

After having exerted a bearing force on one of the skis, the skier raises this ski so as to bring it forward while he slides on the other ski.

In point of fact, it is frequently observed that, when the skier raises his ski while he slides on the other, the tip tends to come into frictional contact against the snow. When the tip scrapes the snow in this way, it disrupts the skier's movement by reducing his efficiency and, in certain cases, even risks causing him to fall.

The object of the invention is to eliminate or at the very least greatly reduce these scraping effects of the tip, which skiers commonly call “snow-shovel” effects.

SUMMARY OF THE INVENTION

The invention therefore relates to a cross-country ski having a tip extending beyond the front contact line.

According to the invention, the projection of the side line of the tip of the ski over a horizontal plane has an inflection point located forward of the front contact line, at least on one side of the ski.

In other words, the invention consists in reducing the width of the tip in comparison to existing skis, by “narrowing” it. Thus, forward of the front contact line, the ski has a marked narrowing, forming an inflexion point on its side line when the latter is observed from above. Beyond this inflexion point, the tip has a width that decreases less severely up to the end of the ski.

Thus, the tip has a relatively marked variation in its width beyond the front contact line.

In practice, this width reduction may be located at least on the inner side of the ski when the right and left skis are different. Nevertheless, more generally, as skis are usually symmetrical, this width reduction may also be symmetrical relative to the median longitudinal plane, the tip in this case having two inflexion points, one on either side of the ski.

Because the side line at the tip is offset toward the median longitudinal plane of the ski, relative to the side line forming the edges, the risks of seeing this tip scrape the snow when the skier brings his ski forward are greatly reduced.

This result of better “skiability” is combined with a slight reduction in the weight of the ski tip and thus of the ski, which gives rise to a reduction in the ski's overall inertia. This combination improves the ski's behavior.

In practice, it was observed that the effects sought were satisfactory when the width of the tip measured midway between the end of the tip and the front contact line is between 40 and 80%, preferably between 50 and 75%, of the width measured in the region of the front contact line.

BRIEF DESCRIPTION OF THE FIGURES

The way in which the invention is implemented and also the advantages arising therefrom will become clearly apparent from the description of the embodiment that follows, based on the appended figures, in which: [0016]
FIG. 1 is a side view of a cross-country ski according to the invention; [0017]
FIG. 2 is a top view of the ski in FIG. 1.[0018]

IMPLEMENTATION OF THE INVENTION

The front of the cross-country ski ([0019] 1) shown in FIG. 1 lies in a horizontal plane H. The front contact line (2) illustrated in FIG. 1 corresponds to the longitudinal level of the ski where the sole (3) ceases to be in contact with the horizontal plane H. The tip starts beyond this front contact line (2). This tip is curved upward as far as its end (5).
According to the invention, and as illustrated in FIG. 2, the tip ([0020] 4) has two inflexion points (6, 7) located on either side of the median longitudinal plane (8). More precisely, these inflexion points occur on the projection of the side line of the tip (4) over the horizontal plane on which the sole (3) lies.
The inflexion point is understood in its geometrical definition as the point ([0021] 6, 7) where the side line of the tip (4) crosses its tangent (15). Thus, to the rear of the inflexion point (6, 7), the portion (10, 11) of the side line has a curve oriented toward the inside of the ski. Conversely, forward of this inflexion point (6, 7) , the portion (12, 13) of the side line has a curve oriented toward the outside.
Therefore, the tip ([0022] 4) has a narrowing of its width that moves it away from the profile (16, 17) shown in dotted lines in FIG. 2, corresponding to the extension of the side line (18, 19) to the rear of the front contact line 2.
In the embodiment illustrated, the two inflexion points ([0023] 6, 7) are located at the same longitudinal level, but in other variant embodiments that are not shown they may be offset longitudinally and be located closer to or farther away from the front contact line.
In practice, and by way of example, the width L of the board in the region of the front contact line ([0024] 2) is of the order of 38 millimeters. The width l, measured in a horizontal plane midway between the projection (9) of the end (5) of the tip (4) and the front contact line (2) is of the order of 26 millimetres.
It emerges from the foregoing that the cross-country ski according to the invention has several advantages owing to the narrowing of its tip. Particular mention may be made of the quasi-elimination of the risk of scraping the snow in the region of the tip during the movements to bring the ski forward when skating. Mention will also be made of a slight reduction in the weight of the tip of the ski, and therefore of the ski, which gives rise to a reduction in the ski's overall inertia, which improves its behavior. [0025]

Claims

1. A cross-country ski (1) having a tip (4) curved upward, extending beyond the front contact line (2), wherein the projection of the side line of the tip (4) of the ski over a horizontal plane H has an inflexion point (6, 7) located forward of the front contact line (2), at least on one side of the ski.

2. The ski as claimed in claim 1, wherein the projection of the side line of the tip (4) of the ski over a horizontal plane has two inflection points (6, 7) located forward of the front contact line, on each side of the ski.

3. The ski as claimed in claim 2, which is symmetrical relative to its median longitudinal plane, at least in its tip zone.

4. The ski as claimed in claim 3, wherein the width l of the tip (4) measured midway between the end (5) of the tip (4) and the front contact line (2) is between 40 and 8%, preferably between 50 and 75%, of the width L measured in the region of the front contact line 2.