EP1145742B1 - Alpine ski - Google Patents

Abstract

The alpine ski comprises a tip zone (2), a heel zone (4) and an intermediate support zone (3). The support zone receives a stop (12) and a heel piece (13) constituting the ski boot fixing. The resistance to bending in the ski longitudinal direction of the central part of the support zone is less than that in the two end parts of the support zone.

Description

The present invention relates to an alpine ski. Alpine skiing has a front area called the tip area, a back area called the heel area and an intermediate zone called the skate zone.

Figure 1 of the accompanying schematic drawing shows a ski alpine seen in profile in which the tip zone, skate zone and heel zone are designated by the references 2, 3 and 4. It also appears from this figure 1 that the thickness of the ski varies over the length thereof, the thickness being significantly higher in the skate area than in the areas end, i.e. tip and heel areas. Indeed, the fixing of a The skier's shoe is mounted in the skate area. So this is the area which must be the most resistant, and it is through this skate area that passes most of the efforts between the snow and the skier's shoe.

It follows from this structure that the stiffness of a ski, that is to say the flexural strength is not constant over the entire length of the ski. As shown in Figure 2 which represents a curve in which the length of the ski is carried along the abscissa axis and the stiffness is carried along the ordinate axis, it is visible that the stiffness of the ski is much larger in the skate area (P) than in the tip areas (S) and heel (T). The fact of mounting the binding in the area skate and the use of ski boots with a very rigid sole, further increases the stiffness compared to the stiffness of the ski considered alone. he this results in an increase in the difficulty to achieve the curve ski.

The stiffness of a ski is measured as follows: the ski is laid flat between two distant supports of a length L (from 200 to 600 mm), a load F between 40 and 60 kg is applied at mid-distance of these supports. The deformation of the ski under this load is then measured (arrow). Then the ski is moved in order to carry out this measurement on another zone (displacement between 50 to 200 mm). The different values arrow allow to define the stiffness curve shown in figure 2.

To remedy this addition of rigidity by the shoe-binding assembly in the skate area, it was imagined to mount the binding, that is to say a stop and a heel not directly on the ski, but on an intermediate plate fixed locally on the ski for example to one of its ends and mounted with the possibility of sliding on the ski by its other end, which allows unlocking. Such a plate is known by document CH 671 887. This unlocking function allows actually remove the influence of the tension springs from the heel piece on the sole of the shoe increasing the bending of the ski, but such a plate nevertheless contributes, due to its inherent rigidity, to increase the stiffness of the ski. It is also known to make a plate for mounting a shoe binding which has notches favoring its flexion. Such a plate is known from the document FR 2,763,861.

However, by making the plate flexible, we lost the concept of unleashing; moreover, this solution requires the implementation a plate which increases the weight of the ski-binding assembly.

The object of the invention is to define the stiffness of a bare ski in anticipating the influence of the binding-shoe assembly necessary for the use of skiing.

For this purpose, in the alpine skiing which it concerns, the stiffness, that is to say the resistance to bending in the longitudinal direction of the ski, of the part center of the skate area is less than the stiffness in both parts end of the pad area, i.e. the connecting parts with the front and rear zones respectively.

This ski therefore differs from a classic alpine ski in which the stiffness curve, i.e. the resistance to bending in the direction longitudinal of the ski placed flat between two supports, is practically a function of the variation in thickness of the ski, that is to say that the stiffness is generally increasing from the extremities towards the central zone of the skate.

Advantageously, in the central part of the skate area, the stiffness is at least 5% lower than the lowest stiffness of the parts end of the skate area.

Reducing stiffness in the central part of the area pad, will allow to homogenize the stiffness over the length of the area shoe, after taking into account the stiffening provided by the mounting of the shoe inside the binding.

Different solutions can be implemented to obtain this reduction in stiffness, with different ski structures, whether a ski with a traditional structure, that is to say comprising a set lower, resistant longitudinal walls called edges, arranged on either side of a central core, and an upper assembly, of a so-called ski with shells, that is to say comprising an outer casing of material synthetic reinforced on the inside of the ski by at least one layer of laminated fabric, forming the upper wall and the side walls of the ski and the edges of which rest directly or indirectly on the edges, or still a ski with a mixed structure, that is to say comprising a hull of which the edges rest on longitudinal reinforcing elements, present at least in the central part or skate area of the ski.

According to a first embodiment of this ski, in the case where it has visible longitudinal reinforcing elements on the side walls of the ski and called edges, the reduction in stiffness in the skate area of the ski is obtained by a localized decrease in the height or thickness of the edges.

In this case, the localized decrease in edge height can be total, and result in an interruption in the central part of the skate area.

According to a second possibility, the reduction in stiffness in the central part of the skate area is obtained by a localized reduction the width of the upper part of the ski, the lower part comprising the sole and the remaining edges of traditional width.

According to a third possibility, the reduction in stiffness in the central part of the skate area is obtained by bringing together localized upper and / or lower reinforcements and the neutral fiber of the ski.

According to another possibility, the reduction in stiffness in the central part of the skate area is obtained by a localized decrease in the thickness of the ski.

According to one embodiment of the ski according to the invention, in the case where it has a structure comprising a material shell synthetic reinforced on the inside of the ski by at least one layer of laminated fabric, forming the upper wall and part of the walls side of the ski and whose edges rest on longitudinal elements reinforcement visible on the side walls of the ski, and which take support directly or indirectly on the edges, reducing the stiffness in the skate area of the ski is obtained by a decrease in the height or by a localized deletion of the longitudinal elements of reinforcement in favor of an increase in height of the side walls of the hull in this area.

Whatever the structure of the ski, the length of the reduction in stiffness is of the order of 200 mm to 600 mm, and preferably between 400 and 500 mm.

Figure 1 est une vue de profil d'un ski alpin.

Figure 2 est une vue représentant la variation de raideur d'un ski traditionnel, sur la longueur de celui-ci.

Figure 3 est une vue représentant la variation de raideur d'un ski selon l'invention, sur la longueur de celui-ci.

Figure 4 est une vue en perspective d'un premier ski.

Figure 5 en est une vue schématique en coupe transversale et à échelle agrandie suivant la ligne V-V de figure 4.

Figure 6 est une vue en perspective d'un second ski.

Figure 7 est une vue schématique en coupe transversale et à échelle agrandie de ce ski suivant la ligne VII-VII de figure 6.

Figure 8 est une vue en perspective d'un troisième ski.

Figure 9 est une vue de côté et à échelle agrandie de la partie centrale de la zone patin du ski de figure 8.

Figures 10 et 11 sont deux vues en coupe transversale et à échelle agrandie de ce ski respectivement suivant les lignes X-X et XI-XI de figure 8.

Figure 12 est une vue de côté et éclatée d'un noyau composant un quatrième ski.

Figure 13 est une vue de côté de ce ski en position montée.

Figures 14 et 15 en sont deux vues en coupe transversale suivant les lignes XIV-XIV et XV-XV de figure 13, respectivement.

In any case, the invention will be clearly understood, with the aid of the description which follows, with reference to the appended schematic drawing representing, by way of nonlimiting examples, several embodiments of this ski.

Figure 1 is a side view of an alpine ski.

Figure 2 is a view showing the variation in stiffness of a traditional ski, over the length thereof.

Figure 3 is a view showing the variation in stiffness of a ski according to the invention, over the length thereof.

Figure 4 is a perspective view of a first ski.

Figure 5 is a schematic view in cross section and on an enlarged scale along the line VV of Figure 4.

Figure 6 is a perspective view of a second ski.

FIG. 7 is a schematic view in cross section and on an enlarged scale of this ski along the line VII-VII of FIG. 6.

Figure 8 is a perspective view of a third ski.

Figure 9 is a side view and on an enlarged scale of the central part of the skate area of the ski of Figure 8.

FIGS. 10 and 11 are two views in cross section and on an enlarged scale of this ski respectively along lines XX and XI-XI of FIG. 8.

Figure 12 is a side and exploded view of a core making up a fourth ski.

Figure 13 is a side view of this ski in the mounted position.

Figures 14 and 15 are two cross-sectional views along the lines XIV-XIV and XV-XV of Figure 13, respectively.

FIG. 3 represents the stiffness curve of a ski according to the invention, in which the length of the ski L has been plotted on the abscissa and in which the stiffness has been carried along the ordinate axis. As shown on this curve, the stiffness in the central part C of the pad P is less than the stiffness in the end parts E and F of the skid zone, i.e. the connecting parts with the spatula zones S and heel T respectively.

To achieve this result, several forms of execution are presented below as examples.

Figures 4 and 5 show a ski having a structure shell, that is to say comprising a shell 5 of synthetic material, reinforced on the inside of the ski by at least one layer of fabric laminate, not shown in the drawing, forming the upper wall 6 and the side walls 7, 8 of the ski and the edges of which rest on the edges 11. This ski has a lower assembly incorporating a sliding sole 9 disposed between the edges, as well as a central core 10 resting on the lower assembly and forming the interior of the ski. Reinforcement elements are provided, which have not been shown in the drawing insofar as they do not relate to the invention. As shown in Figure 4, the part center of the skate area is used for mounting, on the upper face of the ski, a stop 12 and a heel piece 13 constituting the attachment of a skier's shoe.

In the embodiment of the ski represented in FIGS. 4 and 5, the reduction in stiffness in the central part of the skate area is obtained by a localized reduction in the width of the hull made on both sides and other side of the median longitudinal axis of the ski. This translates, as shown in the drawing, by recessed zones 14 obtained by an increase of the inclination of the side walls 8 in this zone relative to the walls side 7 of the ski over the rest of the length thereof. It emerges from Figures 4 and 5 that in the central part of the skate area the width of the upper zone 6 is reduced.

Figures 6 and 7 show a second ski, which is also a ski with shell structure, having the same general characteristics than the first ski. The same elements are therefore designated by the same references than before.

In this second ski, the decrease in the stiffness in the part center of the skate area is obtained by a localized decrease in the thickness of the ski, in a zone 15 located between the stop 12 and the heel piece 13.

Figures 8 to 11 show a third embodiment of a ski according to the invention. In this ski, the same elements are designated by the same references as above. This ski has a hull in synthetic material 16, reinforced on the inside of the ski, that is to say on the side of the core 10 by at least one layer of laminated fabric, not shown in the drawing. The shell 16 forms the upper wall 17 and a part of the side walls 18, and its edges rest on elements longitudinal reinforcement 19, visible on the side walls of the ski, and which rest on the edges 11. This structure is clearly visible Figures 8 and 11. The decrease in stiffness in the central part of the ski skate area is obtained by localized removal of elements longitudinal reinforcement 19 in favor of an increase in the walls side 18 of the shell, as can be seen in FIGS. 8, 9 and 10. In the central part of the skate area, the lower edges of the shell 16 rest directly on the edges. A variant of this ski would consist of decrease the height of the reinforcing elements in the central part of the skate area, without completely removing them.

Figures 12 to 15 show another ski in which the same elements are designated by the same references as previously. In this ski, the core 10 has, in the central part of the skate area, a cavity 20. As shown in FIG. 12, a shim 24 is designed to match the shape of the cavity 20.

Figures 13 to 15 schematically represent a ski in accordance with this embodiment constituted as follows: after placing in a mold, the sole 9, the edges 11 and the core 10, there is a reinforcing fabric 22, so that it matches the shape of the core 10 so of the cavity 20, then we have the wedge 24 to fill the cavity 20, and finally this cap is capped by the shell 23. This structure reduces the stiffness of the ski in the central part of the skate area of it. This reduction in stiffness could be obtained in variants not using a shim, but in which the upper reinforcement 22 or the lower reinforcement, not shown, approaches neutral fiber of the ski, in the area where the stiffness must be decreased.

As is apparent from the above, the invention provides a great improvement to the existing technique by providing a ski whose structure, the term structure being taken in the broad sense and being able to designate both an arrangement of materials and dimensions, allows to homogenize the stiffness in the central part of the skate area, without require the implementation of complex means, and on the contrary, in certain forms of execution, by reducing the quantity of material and by then the weight and the cost price of the ski.

It goes without saying that the invention is not limited only to embodiments of this ski described as examples, it embraces on the contrary all the variants. It is in particular that some ski features that have been described in isolation could be combined, for example, a reduction in width combined with a thickness reduction, without leaving the framework of the invention.

Claims (9)

1. Alpine ski comprising a front zone known as a tip zone (2), a rear zone known as a tail zone (4) and an intermediate zone known as a runner zone (3) intended to receive a toe-piece (12) and a heel-piece (13) constituting the binding of the boot of a skier, characterized in that the rigidity, that is to say the bending strength in the longitudinal direction of the ski, of the central part of the runner zone (3) is lower than the rigidity in the two end parts of the runner zone (3), that is to say the parts connected to the front (2) and rear (4) zones respectively.
2. Alpine ski according to Claim 1, characterized in that the rigidity in the central part of the runner zone (3) is lower by at least 5% than the lowest rigidity of the end parts of the runner zone.
3. Alpine ski according to one of Claims 1 and 2, characterized in that the reduction in rigidity in the central part of the runner zone (3) is obtained by localized moving of the upper and/or lower reinforcements (22) closer to the neutral axis of the ski.
4. Alpine ski according to one of Claims 1 and 2, characterized in that, in cases where the ski has longitudinal reinforcement elements (19) visible on the lateral walls of the ski and called sidewalls, the reduction in rigidity in the runner zone of the ski is obtained by a localized reduction in the height or in the thickness of the sidewalls.
5. Alpine ski according to Claim 4, characterized in that the reduction in rigidity in the central part of the runner zone is obtained by a localized discontinuity of the sidewalls (19) in this part.
6. Alpine ski according to one of Claims 1 and 2, characterized in that, in cases where it has a structure comprising a shell (16) made of synthetic material which is reinforced on the inside of the ski by at least one layer of laminated fabric, which forms the upper wall and part of the lateral walls of the ski and the margins of which rest on longitudinal reinforcement elements (19) which are visible on the lateral walls of the ski and are supported directly or indirectly on the edges (8), the reduction in the rigidity in the runner zone of the ski is obtained by a reduction in the height or by localized omission of the longitudinal reinforcement elements (19) in favour of an increase in height of the lateral walls (18) of the shell (16) in this zone.
7. Alpine ski according to one of Claims 1 and 2, characterized in that the reduction in rigidity in the central part of the runner zone (3) is obtained by a localized reduction (15) in the thickness of the ski.
8. Alpine ski according to one of Claims 1 and 2, characterized in that the reduction in rigidity in the central part of the runner zone (3) is obtained by a localized reduction (14) in the width of the upper part of the ski, the lower part comprising the base and the edges remaining of conventional width.
9. Alpine ski according to one of Claims 1 to 8, characterized in that the length of the zone of reduction in rigidity is of the order of 200 mm to 600 mm, and preferably lies between 400 and 500 mm.

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