EP1925344A1 - Curve of a ski profile - Google Patents

Abstract

The ski (1) has a central zone positioned between a front tip (5) and a rear end (6). The central zone forms a front contact line and a rear contact line with a planar surface when positioned on the planar surface. The front contact line is positioned closer to the front tip than to the rear end, and the rear contact line is positioned closer to the rear end than to the front tip. A distance separating the front contact line from the front tip is greater than 500 millimeters. A shovel is positioned between the front tip and the front contact line.

Description

The present invention relates to skis sliding on snow.

To allow use on different kinds of snow, a ski generally has on the one hand a fairly large length and on the other hand a variable width, the central zone being generally narrower than the end zones.

When a skier practices skiing in powder snow with skis mainly designed for practice on snow groomed, he is forced to change his way of skiing and in particular to change the position of his body. A good, safe and effective skiing technique requires a forward position, it is said that the skier must "engage in the slope". However, when it is found in powdery snow, the skier must move his body backwards, to prevent the front of his skis from sinking too much into the snow.

In order to improve the use of powder snow, it has been proposed to widen certain areas of the ski and to increase the length of the spatula, the latter being delimited in the direction of the length of the ski between the end. before the ski and the forward contact line, that is to say the line of contact that the ski would make if it lay flat on a flat surface.

The document FR 2 786 108 describes such a ski, in which the front and rear contact lines are closer to the shoe than they are in a traditional ski. On the other hand, such a ski has a very raised spatula whose spatula profile is constituted by a succession of portions all having radii of curvature less than 3 m. Such a ski improves the use in the powder snow, but makes it much more difficult to ski on the slopes, where the snow is groomed. In addition, in a ski like this, the succession of spatula portions each having a different radius of curvature but close in value to that of the adjacent portions, decreases the visual perception of the spatula. However, it has been noticed that this visual perception of the presence of a spatula, that is to say of a zone raised in front, is a psychological factor putting in confidence the skier. One can understand, indeed, that the latter will not fear to be stopped or destabilized by the presence of an obstacle of low height, if it is aware that the ski has a raised spatula.

On the other hand, in the case where the skis are made flat and twisted to form a spatula, it lacks continuity because it consists of a succession of portions having a straight profile interconnected by zones of 'angle. In this case, it is considered that there is no tangency between the profile of the spatula and the profile of the central portion of the ski, on the one hand and between the profiles of the different portions of spatulas between them, of somewhere else. If such a construction does not pose a problem when the skis have spatulas with modest dimensions, it becomes problematic in terms of stability, skiability as soon as the length of the spatula increases. Especially since, when a ski has a large spatula made by the method, consisting of twisting skis, there is the presence of "flat" more or less important. We call "dishes" each portion of the ski sole whose profile equates to a right. To detect the presence of "flat", the ski is placed on a flat surface, then the heel is removed so that the point of contact between the sole and the flat surface moves from the front contact line to the ground. end of the ski. This is a movement of unwinding the sole on a flat surface. During this unwinding movement, as soon as the contact between the sole and the flat surface is no longer a simple line transverse to the longitudinal direction of the ski, but a surface, it is considered that this surface constitutes a "flat". The more important a "dish" is, the more harmful it is for the ski's stability of behavior.

In contrast, a ski that has no "flat" is a ski with healthier and more stable behavior that will have more grip. In addition, when skiing in powder snow, the presence of a "flat" in the spatula portion can cause a settlement of the snow at this "flat", which creates a blockage.

The present invention aims to provide a ski that allows to overcome the limitations posed by the devices known in the prior art. In particular, the invention aims to provide a ski whose behavior is optimal both in the powder snow but also on groomed track.

On the other hand the invention aims to improve the behavior of the ski on the snow groomed.

The object of the invention is obtained by providing a ski intended to receive the boot of a user and having a front tip, S, a rear end, T, and a central zone placed between the front tip and the rear end and which when it is placed on a flat surface has at least two lines of contact with said flat surface which are on the one hand, the forward contact line, LS, which is placed close to the front tip and on the other hand, the rear contact line, LT, which is close to the rear end, the distance, DS, separating the front contact line, LS, from the ski tip, S, being greater than 500 mm, i.e., DS> 500 mm.

• une première partie de spatule dont le profil latéral est compris entre un arc de cercle de rayon 9 m et un arc de cercle de rayon 5 m ;
• une deuxième partie de spatule contiguë à ladite première partie de spatule, dont le profil est compris entre un arc de cercle de rayon 9 m et un arc de cercle de rayon 1 m ;
• une troisième partie de spatule contiguë à ladite deuxième partie de spatule, et s'étendant jusqu'à la pointe avant S du ski.

Preferably, the portion placed between the front tip S and the front contact line LS, called a spatula, is constituted by a convex zone which comprises:

• a first spatula portion whose lateral profile is between a circular arc radius 9 m and a circular arc radius 5 m;
• a second spatula portion contiguous to said first spatula portion, whose profile is between a circular arc radius 9 m and a circular arc radius 1 m;
• a third spatula portion contiguous with said second spatula portion, and extending to the front tip S of the ski.

Preferably, the profile of the first spatula portion and the second spatula portion has no "flat".

Preferably, the profile of the first spatula portion and the second spatula portion is such that regardless of the pairs of points P1 and P2 placed at a rope distance from each other of 150 mm on the curve reproducing the lateral profile of the spatula, it there is at least one point of said curve between P1 and P2 which is more than 0.5 mm distant from the rope joining P1 to P2.

In one embodiment of the invention, said first spatula portion has a circular arc profile of radius R1 between 5 m and 9 m, and said second spatula portion has a profile in a circular arc of 3 m and 1m.

In one embodiment of the invention, said third spatula portion has a length of between 80 and 130 mm.

Preferably, the height H which corresponds to the distance separating said flat surface of the ski measured at a point 300 mm distant from the front tip of the ski is between 5 mm and 25 mm, that is to say; 5 mm <H <25 mm.

In one embodiment of the invention, the distance, DT, separating the rear contact line LT from the rear end T is less than 300 mm, that is to say: DT <300 mm.

• La figure 1 est une vue d'ensemble d'un ski selon l'invention équipé de dispositifs de retenue d'une chaussure.
• La figure 2 est une vue de côté du ski de la figure 1.
• La figure 3 est une vue de dessous du ski de la figure 1.
• La figure 4 est une vue de côté partielle du ski de la figure 1.
• La figure 5 décrit l'espace dans lequel s'inscrit le profil de la spatule du ski selon l'invention.
• La figure 6 décrit le détail de la courbe reproduisant le profil latéral de la spatule d'un ski selon l'invention.

The invention will be better understood on reading the following description to which is appended the drawing in which:

• Figure 1 is an overview of a ski according to the invention equipped with retaining devices of a shoe.
• FIG. 2 is a side view of the ski of FIG.
• Figure 3 is a bottom view of the ski of Figure 1.
• Figure 4 is a partial side view of the ski of Figure 1.
• FIG. 5 describes the space in which the profile of the spatula of the ski according to the invention is inscribed.
• FIG. 6 describes the detail of the curve reproducing the lateral profile of the spatula of a ski according to the invention.

The ski 1 according to the invention is an elongated structure which extends from a front tip 5 to a rear end 6. The lower surface, called sole 8, is generally flat and is intended to slide on the snow. The upper surface 7 is also generally flat, but may however have some reliefs.

In the central area of the ski, a line, called the middle line of shoe MC is materialized. This line corresponds to the recommended location of the middle of the shoe 4 when the latter is in place between the retaining means which are fixed on either side of the shoe center line MC.

The retaining means consist of a stop 2 placed in front of the line MC and the heel 3 placed behind the line MC. They are used to hold the shoe 4.

FIG. 2 shows a side view of the ski 1 represented while it is placed on a flat surface 9. Two portions of the latter, one at the front, the other at the rear, are in contact with the 9. These contact areas are in fact two lines which are respectively called front contact line, LS, and heel contact line, LT. Between these two contact lines, the ski has a concave curvature called, camber. On the other hand, it is between these two lines of contact that we fix the retaining elements of the shoe.

Beyond the front line of contact, LS, the portion of the ski between it and the front tip, S, is called a spatula. The length of the spatula, DS, corresponds to the distance separating the front contact line, LS, from the front tip, S. According to the invention, this length is greater than 500 mm. In the example described, the total length of the ski L is equal to 1920 mm and the length DS is equal to 730 mm.

Thanks to this spatula of great length, we reduce the risk of charging when skiing in powder. However, the skier may, even when skiing off-piste in the powder, put his body in the forward position and keep a position similar to that he takes when skiing on groomed trail.

The position of the front contact line, LS, is such that the distance, DM, separating it from the middle of the shoe, MC, is greater than 300 mm.

The portion of the ski placed between the rear contact line, LT and the rear end T defines what is called the heel of the ski. In the ski according to the invention, the heel is much smaller in size than the spatula. The rear contact line, LT, is positioned at a distance, DT, from the rear end, T, of the ski which is less than 300 mm. In the example described, this distance is equal to 100 mm.

Figure 3 shows a top view of the ski described in Figures 1 and 2. It shows the respective positions of the front and rear contact lines LS and LT and the shoe center line MC. The lines corresponding to the maximum width of the ski in the spatula zone and in the heel zone and the minimum width line of the ski in the central zone of the ski are also visible.

The line of minimum width of the ski, LWP, is placed near the shoe center line, set back from it. The width of the ski at this line is commonly called the skate width. The shoe width is between 100 and 150 mm. In the example described, the shoe width is 127 mm.

The line of maximum width of the ski at the heel, LWT, is located near the rear contact line, LT, between the latter and the rear end, T, of the ski. It should be noted that the line LWT can also be located exactly at the level of the rear contact line LT. The width of the ski measured on this line is commonly called heel width. The heel width is between 110 and 160 mm. In the example described, the heel width is 137 mm.

The line of maximum width of the ski at the spatula, LWS, is located between the front end of the ski and the forward contact line, LS, at a distance DWS of the latter. The distance DWS is between 440 mm and 640 mm. In the example described, it is 540 mm. The width of the ski on this line is commonly called the spatula width. The spatula width is between 125 mm and 170 mm. In the example described, it is 147 mm.

When the ski is flat on the snow, the lower edges in contact with the snow are limited to the edges located between the rear contact line, LT, and the forward contact line, LS. When the ski is no longer flat on the snow and the skier takes the angle, the contact length increases to a maximum defined by the distance between the line of maximum width at the level of the spatula LWS of the line of maximum width at the heel LWT.

In the ski according to the invention the distance between the lines of maximum width is much greater than that between the front and rear contact lines. With this, as soon as the skier takes a turn and he goes on the edge, the edge length engaged with the track is more important.

Figure 4 describes in side view the spatula of the ski. From the front contact line, LS, and up to the front end, it consists of three parts. The first spatula portion 10 is contiguous and tangential to the central portion of the ski. It has a lateral profile with a low convexity. Thanks to this very low convexity, the curvature of the lateral profile of the ski has a better continuity at the junction between the central portion of the ski and the spatula.

For example, we can give this part a lateral profile of the type of arc whose radius R1 is between 4 m and 9 m. In this case, in the example described, the radius R1 is equal to 6 m.

By choosing a profile arcuate circle, it ensures a better continuity from the central portion to the tip of the ski if the profile of the spatula is formed by portions of the right. On the other hand, the profiles of the central portion and the spatula are, at the level of the contact line before LS, rigorously tangent.

The choice of an arcuate profile is not limiting in the context of the invention. We can also choose other profiles provided that they fit in the space between two arcs passing through the point LS and tangent, at this point, the profile of the central portion of the ski. The two arcs of the circle in question are, on the one hand, an arc of circle of radius 9 meters and, on the other hand, an arc of circle of radius 5 meters. It will be noted, moreover, that we speak here of the point LS, while we have designated higher LS as being the forward contact line. This is not a contradiction in that when you look at the side profile of the ski, the LS line is a point.

The profile of the first spatula portion 10 extends from the point LS to the intermediate point J1.

The second part of the spatula 11 is contiguous and tangent to the first spatula part. It has a lateral profile with a greater convexity. For example, this part may be given a lateral arc-like profile whose radius R2 is between 1 m and 9 m, preferably between 1 m and 3 m. In the present case, in the example described, the radius R2 is equal to 1.5.

For the second spatula portion 11, either, the choice of an arcuate profile is not limiting within the scope of the invention. It is also possible to choose other profiles provided that they fit in the space between two arcs passing through the point J1 and tangent, at this point, to the profile of the first spatula portion 10. The two arcs of the circle in question are, on the one hand, an arc of circle of radius 9 meters and, on the other hand, an arc of circle of radius 1 meter.

The profile of the second spatula portion 11 extends from the intermediate point J1 to the intermediate point J2.

Because of the very low convexity of the first spatula portion 10, it is almost not visible, except to put the ski on a flat surface and look in profile. The second part of the spatula, may have a greater convexity, it can be more visible and improve the visual perception of the spatula for the skier.

One can choose the same convexity for the first and the second part of spatula. For example, a spatula whose profile has only one radius of curvature R1.

In all cases and to further improve the visual perception of the spatula by the skier, we can proceed to a shaping of the third part of spatula 12 with an even greater curvature. The third part of spatula 12 is the end part of the spatula. It is contiguous and tangential to the second spatula portion 11 and has a length E of between 80 mm and 130 mm. In the example described, the third spatula portion has a length E of 120 mm measured from the end S of the ski.

The profile of the third spatula portion may take the form of an arc of radius R3, with R3 ≤ R2 ≤ R1.

FIG. 5 describes the space in which the profile of the spatula of the ski according to the invention is inscribed. In the graph of FIG. 5, the abscissa axis corresponds to the plane surface 9, while the ordinate axis corresponds to the height of the ski sole from the flat surface 9. The bottom curve 15 corresponds to the profile of a spatula which from the point LS, to the point J2 would have the convexity of an arc of circle of radius equal to 9 meters. While the curve of the top 16 corresponds to the profile of a spatula which from the point LS, to the point J1 would have the convexity of an arc of radius of radius equal to 5 meters, then from the point J1 to the point J2 , the convexity of a circular arc of radius 1 meter.

Any spatula profile, of which the first and second spatula parts, that is to say the portions situated between the points LS and J2, fit into the space delimited by these two curves 15, 16 and which does not present no "dishes" corresponds to a spatula profile according to the invention. The absence of "flat" is noted by the test of "unrolled ski at the spatula". We put the ski on a flat surface, we raise it by the heel, that is to say the rear part, then we see that the contact between the sole of the ski and the contact surface moves from the line of contact LS to the tip S and that during this movement said contact consists of a single line. At no time does this become a plurality of lines, or even a surface.

The absence of "flat" is also noted on the curve reproducing the lateral profile of the spatula. It is considered that the spatula has a "flat", when taking two points P1 and P2 of said curve, placed between points LS and S, separated from each other by a rope distance of 150 mm, the curve between P1 and P2 never deviates from the rope joining P1 and P2 with a value greater than 0.5 mm.

Conversely, it is considered that the spatula of the ski does not present "flat" when whatever pairs of points P1 and P2 are placed at a distance of rope from each other of 150 mm on the curve reproducing the lateral profile of the spatula, there is at least one point of said curve between P1 and P2 which is more than 0.5 mm distant from the rope joining P1 to P2. Of course, when we speak here of distance from the curve to the chord, it is the shortest distance, that is to say that measured on the bisector of the chord at the point considered.

Figure 6 describes the detail of the curve 13 reproducing the lateral profile of the spatula of a ski according to the invention. On this curve 13, two points P1 and P2 are placed at a rope distance of 150 mm, that is to say that the rope 14 joining the point P1 at the point P2 has a length of 150 mm. Since according to the invention, the spatula has no "flat", there is at least one point, placed between P1 and P2, at which the distance d between the curve 13 of the rope 14 is greater than 0.5 mm.

The spatula height of a ski is commonly measured by determining, at a point 300 mm from the front tip, the height H which the ski makes relative to a flat surface on which it is posed. The ski according to the invention has a high spatula, because the height H is between 5 mm and 25 mm.

The present invention is not limited to the embodiment described here by way of purely descriptive example, but it covers any equivalent embodiment.

NOMENCLATURE

• 1- ski
• 2- stop
• 3- heel
• 4- shoe
• 5- forehead
• 6- rear end
• 7- upper surface
• 8- sole
• 9- flat surface
• 10- first part of spatula
• 11- second part of spatula
• 12- third part of spatula
• 13- curve reproducing the spatula profile
• 14- rope
• 15- bottom curve
• 16- top curve

Claims (8)

Ski (1) for receiving the shoe (4) of a user and having a nose, S, a rear end, T, and a central zone between the nose (5) and the rear end (6) and when it is placed on a flat surface (9) has at least two lines of contact with said flat surface which are on the one hand, the front contact line, LS, which is placed near the front tip ( 5) and on the other hand, the rear contact line, LT, which is close to the rear end (6);
which ski is characterized in that the distance, DS, separating the front contact line, LS, from the ski tip, S, is greater than 500 mm, $$\mathrm{DS}>500\mathrm{mm}$$

Ski according to claim 1, characterized in that the portion placed between the front tip S and the front contact line LS, called spatula, is constituted by a convex zone which comprises: - A first spatula portion (10) whose lateral profile is between a circular arc radius 9 m and a circular arc radius 5 m; - a second spatula portion (11) contiguous to said first spatula portion (10), whose profile is between a circular arc radius 9 m and a circular arc radius 1 m; a third spatula portion (12) contiguous with said second spatula portion (11); and extending to the front tip S of the ski. Ski according to claim 2, characterized in that the profile of the first spatula portion (10) and the second spatula portion (11) has no "flat". Ski according to claim 2, characterized in that the profile of the first spatula part (10) and the second spatula part (11) is such that whatever pairs of points P1 and P2 are placed at a rope distance one of the other 150 mm on the curve reproducing the lateral profile of the spatula, there is at least one point of said curve between P1 and P2 which is more than 0.5 mm distant from the rope joining P1 to P2. - Ski according to one of the preceding claims, characterized in that said first spatula portion (10) has an arcuate profile of radius R1 between 5 m and 9 m, and said second spatula portion (11) has a profile in a circular arc of 3 m and 1 m. Ski according to one of the preceding claims, characterized in that the third spatula portion (12) has a length E of between 80 and 130 mm. Ski according to one of claims 1 to 4, characterized in that the height H which corresponds to the distance separating said flat surface of the ski measured at a point 300 mm distant from the front tip of the ski is between 5 mm and 25 mm. mm, that is to say: $$\mathrm{5}\mathrm{mm}\mathrm{<}\mathrm{H}\mathrm{<}\mathrm{25}\mathrm{mm}$$

Ski according to one of claims 1 to 5, characterized in that the distance, DT, separating the rear contact line LT from the rear end T is less than 300 mm, that is to say: $$\mathrm{DT}<300\mathrm{mm}\mathrm{.}$$

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