EP0235059B1 - Cross-country ski - Google Patents

Abstract

A cross-country ski extending along a longitudinal centerline has a forwardly pointed and tapered shovel, a rearwardly tapered tail, and an intermediate portion extending therebetween and defining a central binding-attachment location. The shovel is at its widest of a relatively great width and the tail is at its widest of a relatively small width substantially smaller than the great width of the shovel. The intermediate portion is comprised of a front intermediate portion flaring smoothly forward from the binding location where it is of the small width to the shovel where it is of the great width and a rear intermediate portion of a constant width equal to the small width and extending between the front portion and the tail.

Description

The invention relates to a Nordic ski, or cross-country ski, more particularly intended for the practice of skating step, or half skating step.

For the practice of competitive and high-level cross-country skiing, it is now usual to use skis with parallel edges and a narrow tip, because such skis slide more easily and more quickly in the guide tracks arranged in the snow. , than skis with curved dimension lines. The expression "dimension line" should be understood to mean the profile of the edges of the ski, and this is how a ski having curved dimension lines with progressive reduction in its width from its tip and its heel in the direction of the area of skate is an easy ski, but not efficient; it is easy because its greater width in tip and heel makes it easier to hold the course and to change direction; on the other hand, it is not very efficient, because its movement in the tracks causes lateral braking greater than that of a ski with parallel edges.

A new technique for the practice of cross-country skiing has however appeared and has met with great success due to its effectiveness. This is the technique known as "no skater" or "half skater step". According to the so-called "no skater" technique, the skier propels himself, while sliding, thanks to successive thrusts carried out by taking alternately support on each of the skis, placed obliquely to the direction of movement. According to the "half skater step" technique, the skier takes support, by sliding, several times in succession on the same ski placed obliquely to the direction of movement, while the other ski slides in the track. In both techniques, it is thanks to the inner lower edge of the propellant ski that the skier finds his support.

• - augmentation de la rigidité du ski dans la zone de patin,
• - modification de la cambrure du ski car tout fart ou autre moyen de retenue devient inutile, la retenue étant faite par l'appui transversal réalisé par l'un des skis (celui impulseur),
• - diminution de la longueur du ski pour favoriser sa maniabilité,
• - et raccourcissement de la spatule du ski, pour alléger le ski et faciliter son retour.

To facilitate this technique, manufacturers have had to make various modifications to their skis, namely:

• - increased stiffness of the ski in the skate area,
• - modification of the camber of the ski because any wax or other means of restraint becomes useless, the restraint being made by the transverse support produced by one of the skis (the impeller),
• - reduction in the length of the ski to promote its maneuverability,
• - and shortening of the ski tip, to lighten the ski and facilitate its return.

Despite these modifications, the usual skis with parallel edges, however, only allow imperfectly the practice of this "skater step" technique, because with each lateral lateral support on the snow, the ski more or less rips through its zone between the tip and skate, especially if the snow is hard and frozen, and this shift is all the more accentuated as the speed is faster and the track is smoother. The consequences of these faults or these insufficient transverse support of the pusher ski are significant: if the pusher ski slips, the propellant effect decreases and the speed slows down and in extreme cases, a total lack of support results in a fall if the skater's step is practiced at high speed.

• - mise en place d'une carre interne apparente sur au moins une partie de la longueur du ski,
• - interposition d'une plaque métallique entre la semelle et le chant intérieur du ski pour rigidifier le ski et servir d'arête d'attaque,
• - aménagement de plusieurs rainures longitudinales dans la semelle, à proximité de l'arête intérieure du ski,
• - augmentation de la rigidité du ski en torsion.

Various means have been proposed to remedy these support defects, namely in particular:

• - placement of an apparent internal edge over at least part of the length of the ski,
• - interposition of a metal plate between the sole and the inner edge of the ski to stiffen the ski and serve as a leading edge,
• - arrangement of several longitudinal grooves in the sole, near the inner edge of the ski,
• - increased stiffness of the ski in torsion.

It has finally been proposed to adopt conventional dimension lines, namely for example 46 millimeters in tip, 44 in skid and 45 in heel, or even inverted dimension lines, namely for example 44 millimeters in tip, 46 in skate and 42 in heel.

None of these means, however, makes it possible to solve the problem posed, which is to provide a ski allowing the effective practice of the skater's step, while having excellent behavior in course keeping and in ability to change direction.

• - une première zone qui fait suite au talon et qui est de largeur constante,
• - une deuxième zone qui prend naissance en arrière de la zone de pliure métatarso-phalangienne du pied du skieur chaussant ce ski, et qui s'élargit progressivement et de manière curviligne jusqu'à la spatule.

The subject of the invention is a cross-country ski which meets these requirements. Such a ski is equipped with a heel which widens progressively and in a curvilinear manner from the rear end of the ski, as well as a spatula whose width is decreasing in a curvilinear manner to end in point or in rounding more or less pronounced. Between this heel and this spatula are defined two longitudinal zones, successive and adjacent:

• - a first zone which follows the heel and which is of constant width,
• - a second zone which arises behind the metatarsophalangeal fold zone of the foot of the skier wearing this ski, and which gradually widens and in a curvilinear manner up to the tip.

• Figure 1 est une vue en plan par dessus d'un ski de fond habituel à bords parallèles, une échelle supérieure à l'échelle double ayant été adoptée pour la largeur du ski par rapport à l'échelle choisie pour sa longueur;
• Figure 2 est une vue en plan par dessus réalisée dans les mêmes conditions que la figure 1, mais montrant le ski de fond faisant l'objet de l'invention.

In any case, the invention will be well understood, and its advantages and other characteristics will emerge during the following description of a nonlimiting example of embodiment, with reference to the appended schematic drawing in which:

• Figure 1 is a plan view from above of a usual cross-country ski with parallel edges, a scale greater than the double scale having been adopted for the width of the ski relative to the scale chosen for its length;
• Figure 2 is a plan view from above produced under the same conditions as FIG. 1, but showing the cross-country ski which is the subject of the invention.

Considering the usual ski represented in FIG. 1, 1, 2 and 3 respectively designate its tip, its heel and its skate area. It should be observed that the two edges of this ski are rectilinear and strictly parallel from its tip 1 to its heel 2. The heel 2 widens progressively and in a curvilinear fashion between the transverse line A situated at the level of the end rear of the ski and a transverse line B defining the anterior end of the heel. The spatula 1, for its part, is of decreasing width in a curvilinear manner from the transverse line D, to end, at the level of E, in point or more or less pronounced rounding.

• - une première zone 4 qui s'étend entre la transversale B et une autre ligne transversal C située en arrière de la zone 5 de pliure métatarso-phalangienne du pied 6 du skieur chaussant ce ski; cette zone 4 est de largeur constante de sorte que, dans cette zone, les bords 7, 8 du ski sont parallèles,
• - une deuxième zone 9, qui s'étend entre la ligne transversale C ci-dessus définie et la transversale D définissant le début de la spatule; dans cette zone, le ski s'élargit progressivement et de manière curviligne depuis la transversale C et jusqu'à la spatule: les bords 10, 11 du ski s'écartent progressivement l'un de l'autre de manière curviligne pour se raccorder progressivement à la spatule selon une courbe aux lignes douces et harmonieuses.

In the case of cross-country skiing according to the invention, the heel 2 and the tip 1, which are similar to the heel and the tip of the usual ski of FIG. 1, are connected to each other by two zones successive and adjacent:

• - A first zone 4 which extends between the transverse B and another transverse line C situated behind the zone 5 of metatarsophalangeal fold of the foot 6 of the skier wearing this ski; this zone 4 is of constant width so that, in this zone, the edges 7, 8 of the ski are parallel,
• - A second zone 9, which extends between the transverse line C defined above and the transverse D defining the start of the spatula; in this zone, the ski widens progressively and in a curvilinear manner from the transverse C and to the tip: the edges 10, 11 of the ski gradually move away from each other in a curvilinear manner to gradually connect with a spatula according to a curve with soft and harmonious lines.

It should be noted that the word "tip" means not only the front part curved upwards, but also the substantially flat area which extends and connects it to the body of the ski. It is indeed possible that the part of greater width is practically limited to the connection line between the raised part and the flat part of the spatula; this is the case shown in FIG. 2. However, it is also possible for this part of greater width to extend over a certain length area (a few centimeters) before gradual and continuous decline towards the pad area 3.

• - largeur a de l'extrémité arrière du talon (au niveau de A): comprise entre environ 15 et 25 millimètres;
• - largeur b de la zone 4: comprise entre environ 43 et 46 millimètres;
• - largeur d du ski au point de jonction douce (au niveau de D) entre la zone 9 et la spatule 1: comprise entre environ 45 et 50 millimètres;
• - distance développée e entre A et B: environ de 100 à 200 millimètres;
• - distance développée f entre A et C: environ de 500 à 700 millimètres
• - distance développée g entre D et E: environ de 100 à 250 millimètres;
• - distance I entre C et D: déterminée par la longueur du ski.

Preferably, a ski such as that of FIG. 2 has the following dimensional characteristics (dimensions and lengths):

• - width a of the rear end of the heel (at level A): between approximately 15 and 25 millimeters;
• - width b of zone 4: between approximately 43 and 46 millimeters;
• - width d of the ski at the soft junction point (at D) between zone 9 and the tip 1: between approximately 45 and 50 millimeters;
• - developed distance e between A and B: approximately 100 to 200 millimeters;
• - developed distance f between A and C: approximately 500 to 700 millimeters
• - developed distance g between D and E: approximately from 100 to 250 millimeters;
• - distance I between C and D: determined by the length of the ski.

• a = 21 millimètres
• b = 43 millimètres
• d = 48 millimètres
• e = 150 millimètres
• f = 550 millimètres
• 1 = 1170 millimètres
• g = 280 millimètres

For example, the ski represented in FIG. 2 has the following dimensions for a ski with a developed length of two meters, which corresponds to 1.92 meters under the height rod:

• a = 21 millimeters
• b = 43 millimeters
• d = 48 millimeters
• e = 150 millimeters
• f = 550 millimeters
• 1 = 1170 millimeters
• g = 280 millimeters

The arrangement according to the invention makes it possible to obtain a ski which, while exhibiting excellent behavior as regards its movement in the snow, is particularly suitable for practicing the skating step technique and its variants, in particular for example half a skater step. The rear part of this ski has parallel edges which facilitate the practice of the skater's step, while its front part, wider than the rear part, facilitates the trajectory of the ski at the moment of the impulse when practicing the half skater step: the ski used to trigger the impulse phase is positively supported in the snow without ripping. This facilitates the movement of the skier, whatever the snow conditions and whatever the speed of the skier.

In addition to this decisive advantage for the practice of the skater's step, the greater width of the tip 1 provides other advantages. This improves the stability of the skier and makes it easier to change direction.

Claims (5)

1. Cross-country ski, with a heel (2) which widens progressively and in a curved form from the rear end of the ski, and with a tip (1) the width of which decreases in a curved form to end in a point or a more or less pronounced rounded form, characterised in that the heel (2) and tip (1) are separated by two adjacent, successive longitudinal areas:

- an initial area (4) which follows the heel (2) and which is of constant width,

- a second area (9) which commences at the back of the area of metatarso-phalangeal bending (5) of the foot (6) of a skier wearing this ski, and which wides progressively and in a curved form up to the tip.

2. Cross-country ski according to claim 1, characterised by the following dimensions:

- width (a) of the rear and of the heal (2): between approximately 15 and 25 millimetres;

- width, (b) of the initial area (4): between approximately 43 and 46 millimetres;

- width (d) of the ski at the place (D) where the second area (9) and the tip (1) join: between approximately 45 and 50 millimetres.

3. Cross-country ski according to claim 2, characterised by the following lengths:

- designed length (e) of the heel (2): between approximately 100 and 200 millimetres;

- designed length (f) of the heel (2) and the initial area (4) together: between approximately 500 and 700 millimetres;

- designed length of the tip (1): between approximately 100 and 250 millimetres;

- designed length of the second are, (9): determined by the length of the ski.

4. Cross-country ski according to any of claims 1 to 3, characterised in that the wide area of the tip is situated only at the connection between the tip as such (1) and the front area of the body of the ski.

5. Cross-country ski according to any of claims 1 to 3, characterised in that the wide area of the tip (1) extends for several centimetres in the direction of the foot area (3) before narrowing progressively to the latter.

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