EP0577947B1 - Ski having a rib and a support - Google Patents

Abstract

Ski, in particular an Alpine ski, including a lower sliding (gliding) face connected to two lateral faces (2, 3) which are themselves connected to an upper face (4) which comprises a median rib (7) extending longitudinally, at least in the central zone of the ski. The rib is raised with respect to two lowered lateral parts (8, 9) bordering it on each side and on which a support (10) intended to receive the bindings (11a, 11b) bears. The support has the form of an inverted U and comprises an upper wall (100) extending laterally and downwards via two lateral walls (101, 102) in order to constitute a lower housing intended for the passage of the rib (7). The lateral walls (101, 102) of the support (10) comprise at least one recess (131a, 131b) which extends horizontally. The recesses are deformed in the event of overpressure on the support caused during skiing and the support acts as a suspension. <IMAGE>

Description

The present invention relates to a ski, in particular an alpine ski, a monoski or a snowboard.

It relates more particularly to an improvement of this type of ski.

The skis generally used have a lower sliding face connecting to two lateral faces along two lower edges provided with metal edges, the lateral faces connecting to an upper face. The skis have a relatively small width compared to their length, their anterior end being curved upwards to form a spatula. The thickness of the ski is generally greater in the central part than in the front and rear parts of the ski. In the most generally used conventional forms, the width of the lower face of the ski is smaller in the central part than in the rear and front parts, the width being maximum in the front part of the ski, that is to say at the neighborhood of the spatula.

In known ski structures, the upper face of the ski is generally a ruled surface, that is to say defined by the longitudinal displacement of a straight transverse line parallel to the lower face of the ski. In other words, the cross section of the ski is generally a rectangle or a trapezoid, the large opposite sides of the rectangle or the trapezium being formed by the lower face and the upper face of the ski, the small opposite sides of the rectangle or the trapezoid being formed by the side faces of the ski.

The greater thickness of the ski in the central zone gives this central zone increased rigidity. This central zone is also intended to receive the bindings for the adaptation of a user's shoe. On the other hand, the front and rear areas of the ski, which have a reduced thickness, are more flexible and elastically deform when the ski is used. If one wishes to make a ski having good flexibility in the anterior and posterior zones, it is therefore necessary to provide such anterior and posterior zones having a reduced thickness.

A first problem encountered in traditional ski structures is that the central area of the ski, which has a relatively large thickness to give it great rigidity, causes a fairly significant distance of the bindings from the lower edges of the ski. The lower edges are the elements which are intended to bite into the ice, when cornering. The effectiveness of the lower edges provided with edges is all the better as the connection between the user's foot and the edge is more direct. The distance between the edge and the binding tends to degrade the effectiveness of the edges. To remedy this drawback, European patent application No. 465,794 describes a new ski structure having in particular on its upper surface, a middle rib extending longitudinally on either side of the central zone and lowered lateral clearances bordering each side of this rib and on which rests a support or stirrup in the shape of an inverted "U" intended to receive the fixings.

A second problem encountered in current ski structures is that in certain configurations, in particular when the skier is in front support, when entering a curve, or conversely, in rear support, when exiting. a curve ; the part opposite to the support is lightened and loses contact with the snow. To address this problem, French patent applications Nos. 9,016,048, 9,105,012 and 9,204,190, for example, propose replacing the middle rib by an added element, in one or two parts constituting a stiffener, partially linked to a base and which extends longitudinally, at least in the central region of the ski and advantageously beyond, that is to say over a length of between approximately 50 and 80% of the length of the base in contact with snow. The stiffener makes it possible to obtain a balanced distribution of the pressures of the ski in dynamics and to avoid the aforementioned drawback of traditional skis whatever the configuration of the skier. Thus, the ski gains in stability and depending on the adjustment of the stiffener and / or its design, the stability / maneuverability ratio can be improved.

Document EP-A1-0 490 043 also relates to this type of ski with, in addition, a U-shaped stirrup overturned and linked to the base to receive the fastening elements. The support thus constitutes the mechanical transmission and distribution element of the support of the skier on the base. In addition, the stiffener can flex freely without having to directly support the skier's support.

The present invention is an improvement to this type of skis. As has just been explained, these new shapes and structures make it possible to increase the transmission of the efforts of the skier on the edges thanks to a more direct connection between the foot and the edge. This transmission can have a drawback when the ski, driven on the edge at high speed, undergoes a point overpressure such as due to the meeting of an element of hard ice, for example. There can then occur a phenomenon of "stalling" which results in an involuntary lateral sliding of the ski on the side of the slope causing a deviation of trajectory.

The present invention proposes to resolve this drawback by reducing the maximum overpressure points which can be assimilated to a general vibratory phenomenon. The behavior of the ski is improved by the fact that the extreme amplitudes are smoothed and the ski retains directional stability whatever the surface condition of the terrain on which it operates.

The ski according to the present invention is defined in claim 1. Particular embodiments of this ski appear from dependent claims 2 to 16.

The support can deform in the event of overpressure, by reducing the space of the recess and particularly its height. The support plays the role of a suspension making it possible to avoid the phenomenon of "stalling".

We can provide that the side wall of the support located on the inside of the ski, particularly stressed on the edge grips, is crossed by a front recess close to the front stop of the binding and a rear recess near the heel of fixing spaced from each other. Thus, the front recess is requested mainly during the forward support of the skier exerted at the entry of the turn and the rear recess is mainly requested at the exit of the turn.

Advantageously, each side wall of the support is traversed by a front recess and a rear recess spaced from each other.

According to an additional characteristic, the length of each recess is between 15 and 150 millimeters and its height between 0.5 and 6 mm.

• la figure 1 est une vue schématique d'une vue de profil d'un ski selon l'invention,
• la figure 2 est une vue schématique de dessus d'un ski de la figure 1,
• la figure 3 est une vue en perspective d'un ski selon l'invention,
• la figure 4 est une vue en coupe selon (I-I') de la figure 2,
• la figure 4a représente la force F appliquée sur le support en fonction de la variation de hauteur de l'évidement (Δh),
• la figure 5 est une vue en perspective d'un support destiné au ski selon l'invention,
• la figure 6 est une variante de la figure 5,
• la figure 7 est une variante de la figure 1,
• la figure 8 est une vue en coupe selon (II-II') de la figure 7,
• les figures 9 et 10 sont des vues simplifiées et partielles du ski selon l'invention montrant une forme particulière d'évidement,
• la figure 10a illustre la courbe de variation de la flêche en fonction de la force appliquée sur l'évidement, selon la variante des figures 9 et 10,
• les figures 11 et 12 sont des variantes des figures 9 et 10,
• la figure 12a illustre la courbe de variation de la flêche en fonction de la force appliquée sur l'évidement, selon la variante des figures 11 et 12,
• la figure 13 est une autre variante de forme de l'évidement,
• la figure 14 illustre la courbe de la figure 14,
• la figure 15 est une variante de la figure 7,
• la figure 16 est une autre variante.

Other objects, characteristics and advantages of the present invention will emerge from the following description of particular embodiments, given in relation to the attached figures among which:

• FIG. 1 is a schematic view of a profile view of a ski according to the invention,
• FIG. 2 is a schematic top view of a ski from FIG. 1,
• FIG. 3 is a perspective view of a ski according to the invention,
• FIG. 4 is a sectional view along (I-I ') of FIG. 2,
• FIG. 4a represents the force F applied to the support as a function of the variation in height of the recess (Δh),
• FIG. 5 is a perspective view of a support intended for skiing according to the invention,
• FIG. 6 is a variant of FIG. 5,
• FIG. 7 is a variant of FIG. 1,
• FIG. 8 is a sectional view along (II-II ') of FIG. 7,
• FIGS. 9 and 10 are simplified and partial views of the ski according to the invention showing a particular form of recess,
• FIG. 10a illustrates the curve of variation of the arrow as a function of the force applied to the recess, according to the variant of FIGS. 9 and 10,
• FIGS. 11 and 12 are variants of FIGS. 9 and 10,
• FIG. 12a illustrates the curve of variation of the arrow as a function of the force applied to the recess, according to the variant of FIGS. 11 and 12,
• FIG. 13 is another alternative form of the recess,
• FIG. 14 illustrates the curve of FIG. 14,
• FIG. 15 is a variant of FIG. 7,
• Figure 16 is another variant.

As shown in Figures 1 to 4, the ski has a lower sliding face (1) connecting to two lateral faces (2, 3) along two respective lower edges (20, 30) provided with metal edges. The lateral faces (2, 3) are connected to an upper face (4). The front end of the ski is bent upwards to form a spatula (5) between (A-A) and the front end of the ski. The rear end of the ski is slightly curved upwards to form the heel (6) between (D-D) and the rear end of the ski. (A-A) and (D-D) correspond respectively to the front contact line and to the rear contact line of the ski. The ski may in particular comprise a tip tip (50), and a heel protector (60), fixed by any means such as snap-fastening, or gluing for example (as shown in FIG. 3 more specifically).

The upper face comprises a central rib (7) extending longitudinally in the central zone of the ski. We consider the central zone of the upper face of the ski, constituted by the ski part located between 1/3 and 2/3 centered in the middle of the ski between the cutting zones BB and CC shown in FIGS. 1 and 2. In this zone, at least the middle rib (7) is raised relative to two lowered lateral parts (8, 9) bordering it on each side.

The middle rib (7) constitutes a thicker part of the ski, that is to say that the distance between the upper face of the middle rib (7) and the lower face (1) of the ski is increased, to give the central area of the ski with appropriate mechanical rigidity. The length (L ₂ ) of the rib is preferably between 50 and 100% of the length (L ₁ ) of the lower sliding face (1) coming into contact with the snow, that is to say between (AA) and (DD).

A support (10) of length (L) less than (L ₂ ) and having the shape of an inverted "U", intended to receive the fasteners (11) is supported on each lowered side part (8, 9). It is linked to these parts by any means such as gluing, screwing or welding. It comprises an upper wall (100) on which the fasteners (11) are screwed, and is extended laterally and downwards by two side walls (101, 102) to form a housing (12) intended for the passage of the middle rib (7). Thus, it should be noted that the dimensions of the housing (12) both horizontal (l ₁ ) and vertical (h ₁ ) are greater than the respectively horizontal (l ₂ ) and vertical (h ₂ ) dimensions of the rib to form a space " e ".

According to the invention, the side wall (102) of the support (10) located on the inside of the ski (INT) comprises at least one recess (13), preferably two recesses (130a, 130b) spaced apart from one other. In this particular case, the front recess (130a) is located near and below the front stop (11a) of the binding (11) and the rear recess (130b) is located near and below the heel piece (11b) of the fixing. Each recess extends horizontally so that its length (l) is greater than its height (h). The length (l) of each recess is between 15 and 150 millimeters. The length (l) is between 0.02 and 0.75 L when the side wall has only one recess. In general, the length (l) is between (0.02 / n) and (0.75 / n) L when the wall has n recesses.

As shown in Figure 4, each side wall (101, 102) can be crossed by one or more recess (130b, 131b) thus allowing the interchangeability of the right and left ski. For example, each side wall (101, 102) of the support can be provided with two recesses (130a, 130b, 131a, 131b) spaced from one another. It can also be provided that each recess has a different shape and / or length.

qui s'inscrit dans un cône de fonctionnement limité par une limite minimale D₁ et une limite maximale D₂. D₁ correspond à la droite de pente égale à 200N/mm et D₂ à la droite de pente égale à 2000N/mm. Différents paramètres permettent de faire varier la courbe $\text{F=f (Δh)}$

pour chaque évidement dont principalement, la forme de l'évidement, sa longueur, l'épaisseur des parois latérales (101, 102) du support, la rigidité du matériau du support, etc.FIG. 4a represents the force F applied to the support vertically from the center of the recess as a function of the variation in the height of the recess (or clearance). Each recess designed according to the invention is defined by its curve $\text{F = f (Δh)}$

which is part of an operating cone limited by a minimum limit D ₁ and a maximum limit D ₂ . D ₁ corresponds to the straight line with a slope equal to 200N / mm and D ₂ corresponds to the straight line with a slope equal to 2000N / mm. Different parameters allow you to vary the curve $\text{F = f (Δh)}$

for each recess including mainly the shape of the recess, its length, the thickness of the side walls (101, 102) of the support, the rigidity of the support material, etc.

Figures 5 and 6 show two different ways of designing the recesses. Each recess of the support (10) of FIG. 5 is formed by an open recess or depression produced on the lower edge (101a, 102a) of the side wall (101, 102) of depth equal to the height of the recess to be produced . The recess thus constitutes a lumen when the support is in abutment on the lowered lateral parts of the ski. In FIG. 6, each recess (130a, 130b, 131a, 131b) is constituted by a slot made in the side wall proper of the support and located at a certain distance from the lower edge (101a, 102a) of the side wall (101, 102).

The support is made of plastic or composite material accepting a certain deformation. It is produced in one piece, preferably by molding. Provision may be made for the upper support wall to include a metal or fiber-based insert (103), preferably glass, and resin, preferably phenolic, allowing the fastenings to be screwed, as shown in FIG. 6. The insert can be embedded in the plastic during the molding of the support part.

Figures 7 and 8 show a variant in which the ski comprises a first lower assembly or base (40) and a second upper assembly or stiffener (70) intended to complete the distribution of stiffness of the base. The stiffener constitutes the middle rib (7) in the central zone and is raised relative to the lateral parts (8, 9) of the base. The stiffener is partially linked by each of its ends to the base by rigid or flexible connecting means (70a, 70b). The flexible connection means can be constituted by an interface made of flexible elastomeric or plastic material, for example.

The structure of the base (40) can be of the sandwich type or of the box type or of any other type. In FIG. 8, a preferred structure is shown comprising a rigid upper reinforcement (400), in the form of a shell with a "U" section forming a top wall (400a) and two side walls (400b, 400c) covering a core ( 401), the assembly being closed at its lower part by a lower element (402) comprising the metal edges (403), a sliding layer (404) generally made of polyethylene as well as lower reinforcement elements (405). An upper protective and decorative layer (406) covers the upper reinforcement to form the decoration of the base.

The reinforcing layers (400, 405) can be of all types such as layers of composite materials such as fiberglass, carbon fiber with epoxy resin and / or polyester. They can also be made of metal, metal alloy or fibrometal.

The core (401) can be filled or unloaded foam, wood or aluminum honeycomb.

The monolayer or multilayer surface coating providing the decoration can be made of polyamide or other material, such as a thermoplastic material.

The structure of the stiffener may be of the box type with variable section along the ski, and formed of a core disposed between an upper reinforcement and a lower reinforcement (not shown). It can also be made up of a simple reinforced section with a longitudinally evolving section obtained by the TRE, SMC technique.

Figures 9 and 10 show an example of the shape of a recess whose height (h) is constant. The application of a force (F) on the support causes its deformation and the proportional decrease in the height (h) of the recess creating a suspension effect. FIG. 10a represents two examples of curves (C ₁ and C ₂ ) for recesses having the general shape of FIGS. 9 and 10, that is to say at constant height. In comparison, the two curves C ₁ and C ₂ are linear but the slope of C ₁ is less than that of C ₂ because the length of the recess of C ₁ is less than the length of the recess of C ₂ (all other equivalent parameter otherwise).

, dont la pente est supérieure à celle de P₁, correspond à la déformation de la partie centrale de longueur l₄ jusqu'à ce que ${\text{Δh=h}}_{\text{4}}$

.FIGS. 11 to 12a show another example of the shape of the recess, the height of which is variable and which includes an upper edge (14) in steps. In the case presented, the recess comprises a central part of the length (l ₄ ) and height (h ₄ ) located between two lateral parts of length (l ₃ ) and height (h ₃ ); with (h ₄ ) greater than (h ₃ ). FIG. 12a illustrates the curve (C) of variation of the arrow Δh as a function of the applied force F at the center of the recess. This curve is divided into two straight line portions P ₁ and P ₂ . P ₁ corresponds to the deformation of the recess until ${\text{Δh = <figure-callout id="2" label="h" filenames="imgf0001.png,imgf0002.png" state="{{state}}">h</figure-callout>}}_{\text{2}}{\text{and <figure-callout id="2" label="P" filenames="imgf0001.png,imgf0002.png" state="{{state}}">P</figure-callout>}}_{\text{2}}$

, whose slope is greater than that of P ₁ , corresponds to the deformation of the central part of length l ₄ until ${\text{Δh = <figure-callout id="4" label="h" filenames="imgf0001.png,imgf0002.png" state="{{state}}">h</figure-callout>}}_{\text{4}}$

.

FIG. 13 illustrates a triangular-shaped recess, the upper edge (15) of which comprises a first increasing straight portion (150) connecting to a second decreasing straight portion (151).

FIG. 14 shows the progressive variation of the curve of the arrow as a function of the force applied to the point (152) of maximum height (h max).

Of course, other forms of recess can be envisaged.

FIG. 15 shows an advantageous variant of the invention which provides for the integration of the different parts constituting the ski between them. In particular, the stiffener comprises a narrowing of its height (h ₅ ) extending at least over the corresponding length (L) of the support so as to form a clearance to reduce the height (h ₆ ) of the support and therefore the height bindings in relation to snow. Similarly, the height (h ₇ ) of the base varies to allow good integration of the support elements / base / stiffener therebetween.

FIG. 16 illustrates a variant in which the support consists of two independent half-supports (10a, 10b) spaced from one another, a first front half-support (10a) on which the front stop (11a) is fixed ) for retaining the shoe, and a second rear half support (10b) on which the heel piece (11b) is fixed. In this case, one or more recesses (131a, 131b) can be provided on the side walls of each half support.

Of course, the invention is not limited to the embodiments described and shown by way of examples, but it also includes all the technical equivalents as well as their combinations and other variants within the limits of the claims.

Claims (16)

1. Ski comprising a lower sliding surface (1) joined at two lateral surfaces (2, 3) along two lower edges (20, 30), the lateral surfaces joined at an upper surface (4) which comprises a median rib (7) extending longitudinally, at least in the central zone of the ski; said rib being raised with respect to two lateral lowered portions (8, 9) bordering it from each side and on which a support (10, 10a, 10b) takes support, such support being adapted to receive the bindings (11, 11a, 11b) and having the shape of an inverted "U" which comprises an upper wall (100) extended laterally and downwardly by two lateral walls (101, 102) to constitute a lower housing adapted for the passage of the rib (7), characterized in that at least one of the lateral walls (101, 102) of the support (10, 10a, 10b) comprises at least one recess (13, 130a, 130b, 131a) extending horizontally, which is either formed by an open undercut obtained on the lower edge (101a, 102a) of the lateral wall (101, 102) of the support so as to constitute a slot when the support is in support on the lateral lowered portions (8, 9) of the ski, or is a slit obtained in the lateral wall (101, 102) of the support and is located at a certain distance from the lower edge (101a, 102a) of said lateral wall (101), such that the application of a force (F) on the support causes its deformation and the proportional reduction of the height (h) of the recess creating a suspension effect.
2. Ski according to claim 1, characterized in that the lateral wall (102) of the support (10, 10a, 10b) located on the inner side (INT) of the ski is crossed by a front recess (130a) and a rear recess (130b) spaced from one another.
3. Ski according to claim 1, characterized in that each lateral wall (101, 102) of the support (10, 10a, 10b) comprises a front recess (130a, 130b) and a rear recess (131a, 131b) spaced from one another.
4. Ski according any of the preceding claims, characterized in that the length "L₁", of the rib is comprised between 50 and 100 percent of the length "L₂" of the lower sliding surface (1) in contact with the snow.
5. Ski according to claim 4, characterized in that it comprises a first lower assembly or base (40) and a second upper assembly or stiffener (70) which constitutes the median rib (7), and each of whose ends is connected to said base (40) by flexible and/or rigid connection means (70a, 70b).
6. Ski according to claim 5, characterized in that the base (40) is a beam constituted of a core (401) located between two reinforcements, a first upper reinforcement (400) and a second lower reinforcement (405), of a sliding layer (404) laterally comprising two lateral metallic running edges (403), said upper reinforcement being covered at least partially by a superficial protection and decoration layer (406).
7. Ski according to claim 5 or 6, characterized in that the stiffener (70) is constituted of a section comprising one or more reinforcement layers and whose shape changes longitudinally such that its rigidity varies according to the longitudinal position considered.
8. Ski according to any of the preceding claims, characterized in that each recess (13, 130a, 130b, 131a, 131b) is defined by a curve of force F applied on the support (10, 10a, 10b) perpendicularly with respect to the center of the recess as a function of the variation of the height (Δh) of the recess (or clearance) which is comprised in a functional cone limited by, on the one hand, a straight line (D₁) having a slope equal to 20ON/mm, and on the other hand, a straight line (D₂) having a slope equal to 200ON/mm.
9. Ski according to claim 8, characterized in that the height (h) of the recess is constant longitudinally as a function of its length (l).
10. Ski according to claim 9, characterized in that the height (h) the recess is variable longitudinally as a function of its length (l).
11. Ski according to claim 9 or 10, characterized in that the height (h) of the recess is comprised between 0.5 and 6 millimeters.
12. Ski according to claim 9, 10 or 11, characterized in that the length (l) of the recess is comprised between 15 and 150 mm.
13. Ski according to claim 12, characterized in that L being the length of the support (10), the length (l) of each recess is comprised between (0.02/n) and (0.75/n) L when the lateral wall (101, 102) comprises n recesses.
14. Ski according to any of the preceding claims, characterized in that the support is constituted by a single molded element made of a plastic material or a composite material.
15. Ski according to claim 14, characterized in that the upper wall of the support (10) comprises an insert (103) which is metallic or fiber and resin based, embedded in the plastic material enabling the bindings to be screwed.
16. Ski according to any of the preceding claims, characterized in that the support (10, 10a, 10b) is linked to each lateral lowered portion (8, 9) by adhesion, screwing or welding.

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