EP0498053B1 - Ski for winter sport comprising a mounting platform for ski bindings - Google Patents

Abstract

Ski, in particular an Alpine ski, having the form of an elongated beam consisting of a core, a lower reinforcement and an upper reinforcement, and comprising, in the zone for fitting the bindings, at least one shock-absorbing element, characterised in that the said shock-absorbing element is arranged on the first upper reinforcement and under a second central upper reinforcement. <IMAGE>

Description

The present invention relates to a ski, such as an alpine ski, a cross-country ski, a monoski or a snowboard. It relates more particularly to an improvement in this type of ski and in particular of its area for mounting the bindings.

We already know different types of ski and there are many variations. These consist of an elongated beam whose front end is curved upwards to form a spatula, the rear end also being more slightly to form the heel.

Current skis generally have a composite structure in which different materials are combined so that each of them intervenes optimally, taking into account the distribution of mechanical stresses when using the ski. Thus, the structure generally comprises peripheral protection elements, internal resistance elements to resist the flexural and torsional stresses, and a core. These elements are assembled by gluing or by injection, the assembly generally being carried out hot in a mold having the final shape of the ski, with a front part strongly raised in tip, a rear part slightly raised in heel, a central arched part. .

Despite the manufacturers' concern to manufacture good quality skis, they have not, to date found a high performance ski satisfactory in all conditions of use.

Also, a number of attempts have already been made to solve the problems of damping and driving the ski. It has been proposed in particular to interpose between the binding (s) of the boot and the ski, damping devices.

Document WO / 91 12056 (included in the state of the art according to Article 54 (3) EPC) relates to a ski comprising pre-drilled zones in the structure of the ski in the form of longitudinal reservoirs; which are, at least in part, filled with an elastomeric layer and a resistant insert into which the fixing screws are screwed. To allow a certain vertical functional movement of the screws in each tank, it is provided that the slide of the bindings is supported on a mounting plate located at a distance from the covering layer of the ski. Optionally, an elastomeric layer fills the space left free between the mounting plate and the cover layer (Figure 5). Each reservoir extends over a significant part of the thickness of the core.

These devices are intended to improve the comfort of the skier as well as the handling and performance of skis. Without shock absorbers, all the irregularities of the tracks, which are harder and harder because they are better and better groomed, subject the ski to shocks and vibrations which are transmitted directly to the skier whose skeleton, joints, muscles and tendons are very stressed, hence not only discomfort but also fatigue which can lead to accidents. In addition, the excessively rigid connection between the skier and the ski is detrimental to good ski handling, in particular by too great an edge grip in the snow which causes untimely braking. However, the proposed devices are only adaptations which are not entirely satisfactory.

The present invention therefore seeks to overcome these drawbacks by proposing a ski whose damping device is integrated into its structure.

To this end, the ski according to the invention has the form of an elongated beam constituted by a core, a lower reinforcement, an upper reinforcement and a damping element in the area for mounting the bindings; said damping element being disposed on said upper reinforcement and under a second central upper reinforcement, characterized in that the second upper reinforcement is covered with a surface covering layer extending forward (AV) and towards the rear (AR) to cover beyond the mounting area the first upper reinforcement; said mounting area projecting from the general plane of the ski to form an integrated damping platform.

The first upper reinforcement and the second central upper reinforcement consist of layers of composite materials or of a metal alloy, while the core is a synthetic foam, wood or honeycomb, and the surface covering layer is polyamide or thermoplastic material.

According to an additional characteristic, the damping element consists of a strip of elastically deformable material, and for example of viscoelastic material.

According to another arrangement, the damping element consists of at least two independent elements, at least one of which has dimensional and / or mechanical and physical characteristics different from the other. For example, it consists of three independent elements.

According to a variant, the fitted ski is such that the binding retaining screws are anchored both in the first upper reinforcement and in the second central upper reinforcement.

The ski according to the invention makes it possible to satisfy at least three functions: the damping of the structure, a better tolerance of the distribution of pressures and a significant improvement in the suspension of the skier vis-à-vis the shocks received by the ski. Thus, the damping elements are positioned at the places where the deformation is maximum, that is to say at the front and at the rear of the mounting area. The goal is to have a damping gradient all along the mounting area with maximum damping at the ends and minimum in the center. In order to dissipate the energy of the damping element, it is sandwiched between two rigid elements thus causing it to shear.

Other characteristics and advantages of the invention will emerge from the description which follows with reference to the appended drawings, which are given only by way of nonlimiting examples.

Figure 1 is a side view of a first embodiment of a ski according to the invention.

Figure 2 is a top view of Figure 1.

Figure 3 is a cross section along III-III of Figure 1.

Figure 4 is a cross section along IV-IV of Figure 1.

Figure 5 is a partial view on a larger scale in a longitudinal section of the central part of the ski and its area for mounting the bindings.

Figure 5a shows a detail.

Figures 6 to 11 are views similar to Figure 5 showing alternative embodiments.

FIG. 1 represents a ski according to a first embodiment according to the invention. The body of the ski has, in known manner, the shape of an elongated beam having a lower sliding surface (1) and an upper surface (2). The slightly arched central part is extended on the one hand at the front by an anterior part (3) raised to form the tip (4) and on the other hand by a posterior part (5) slightly raised to form the heel of the ski . The rear part (5) being relatively short and of low lift, and the front part (3) being longer and much more arched, as is known per se and shown in the figure.

The structure of the ski body can be of the sandwich type or of the box type or of any other type. In FIGS. 2, 3 and 4, a preferred structure is shown comprising a first rigid upper reinforcement (6) in the form of a shell with "U" section forming a top wall (7) and two side walls (8 and 9), covering a core (10), the assembly being closed at its lower part by a lower element (11) comprising the metal edges (12,13), a sliding layer (14) generally made of polyethylene as well as lower reinforcement elements (15.16). An upper surface layer (17) covers the upper reinforcement to form the decoration.

The reinforcing layers (6,15,16) can be of any type such as layers of composite materials such as fiberglass, carbon fiber with epoxy or polyester resin, or a metal alloy. The core (10) can be filled or unloaded foam, wood or aluminum honeycomb. The surface layer providing the decoration can be made of polyamide. or other such as in thermoplastic material. It can be monolayer or made up of several layers.

The ski comprises in its mounting area (18) bindings (19,20) a damping element (21). According to the invention, this damping element (21) is arranged in the central part of the ski, at the level of the mounting zone (18) of the bindings, on the one hand on the upper reinforcement (6) and more precisely on the upper surface of its upper wall (7) and on the other hand, under a second reinforcement central superior (22). Said damping element is therefore sandwiched between two layers of rigid reinforcement (7,22).

The damping element (21) consists of a strip of resilient material advantageously of the viscoelastic type. This strip of thickness between 0.5 to 6 mm can therefore be made of thermosetting or thermoplastic synthetic viscoelastic rubber or filled PVC: This strip located in the central part (18) at the level of the mounting area of the fasteners does not does not extend longitudinally over the entire length of the ski, but only partially and has a length "X" which depends on the length "L" of the ski. Thus, the length "X" of the damping element can for example be between 400 and 1000 millimeters. The material used to constitute the damping element can be elastic with a hardness of between 60 and 90 shore A, or a viscoelastic material having a damping value of 0.1 to 0.8 (values for a temperature of 20 ° and a frequency of 15 Hz). The second upper reinforcement (22) is in a technical layer of composite materials such as fiberglass or carbon with epoxy or polyester resin, or a metal sheet such as steel or aluminum. This layer can be monolayer or made up of several layers. This second upper reinforcement disposed on the damping element (21) and integral with the latter by gluing or welding has for example a thickness of between 0.5 and 2 mm. The damping element (21) is also glued to the upper wall (7) of the reinforcement (6). In the example shown, it has a length "X" and a width "L1" respectively equal to the length "X" and to the width "L1" of the damping element (21). Since the damping element (21) is arranged on the upper reinforcement layer (7) which extends over the entire length of the ski, the mounting area (18) of the bindings is found to be indoors with respect to in the upper general plane of the ski to form a platform (23) of length "X" and height "h".

It can be seen that the surface layer (17) covering the top of the second central upper reinforcement (22) extends forwards and backwards to cover beyond the platform, the first upper reinforcement (6,7 ). Note also that the screws (24) intended to retain the fixings are anchored both in the first upper reinforcement (7) and in the second central upper reinforcement (22) covering the damping element (21) as shown on Figure 5a ..

According to the first embodiment shown in Figures 1, 2, 3 and 4, the thickness "e" of the strip constituting the damping element is constant, but it could be otherwise, as shown in Figures 6 and 7.

Thus, according to the variant of FIG. 6, the thickness "e" of the damping element (21) is greater at the front (AV) to decrease progressively towards the rear (AR).

According to the variant of Figure 7, the variation is opposite and the thickness "e" of the damping element (21) is greater at the rear (AR) to decrease progressively forward (AV).

FIG. 8 is a variant according to which the second central upper reinforcement (22) extends forwards (AV) and rearwards (AR) beyond the damping element (21) to be integral with the front and rear by its front (220) and rear (221) ends at the upper wall (7) of the first upper reinforcement (6).

FIG. 9 is another variant according to which the lower part of the central part (210) of the damping element (21) comprises a succession of hollow transverse profiles (211). these hollow profiles being intended to give better flexibility to the central part of the damping element.

According to an additional characteristic, the damping element (21) consisting of a single element in the embodiments described above, can also be constituted by two or three distinct elements (Figures 10 and 11). Indeed, the damping element can consist of three independent elements (21a, 21b, 21c) at least one of which is made of a material different from the other two. Thus the front element (21a) can be arranged under the front attachment (19) while the rear element (21c) is arranged under the rear attachment (20), the median element (21b) being in turn, disposed between said front element (21a) and said rear element (21c).

The respective lengths "La", "Lb", "Lc" of the different elements (21a, 21b, 21c) can for example be such that
"La" and "Lc" is between 150 and 190 mm
"Lb" is between 180 and 250 mm.
or
"La" and "Lc" is between 200 and 400 mm
"Lb" is between 150 and 200 mm.

As we said earlier, at least one of the elements is made of a material different from the other two or of dimensional or physical characteristics different from the other two.

Thus the front element (21a) can have mechanical and physical characteristics equal or substantially equal to the rear element (21c), while the median element is different. For example, the front (21a) and rear (21c) element can be of viscoelastic material with a hardness of 70 to 80 shore A and a damping value of 0.1 to 0.4, while the the middle element is made of elastic material with a hardness of 35 to 70 shore A.

We could also have an arrangement such that the front (21a) and rear (21c) elements are made of viscoelastic material with a hardness of 80 to 90 shore A and with a damping value of 0.3 to 0.8, while the middle element is made of elastic material with a hardness of 35 to 70 shore A.

We could also have a provision such that the three elements (21a, 21b, 21c) have different characteristics.

FIG. 11 represents another variant according to which the second central upper reinforcement (22 ′) has, in a longitudinal section, the shape of an inverted Ω constituted by a front horizontal wall (22 ′ a) extended by a front transverse wall (22 '' a) extending downwards then from a central horizontal wall (22'b) extended upwards by a rear transverse wall (22''c) extended rearwards by a rear horizontal wall (22 ' vs). The two front (22'a) and rear (22'c) horizontal walls being spaced a height "e" from the first upper reinforcement (6; 7) to constitute a housing for the front damping element (21a respectively) ) and the rear damping element (21c). On the other hand, the central horizontal wall (22'b) is directly integral with the upper wall (7) of the upper reinforcement (6). The three damping elements (21a, 21b, 21c) can be as in the previous case, identical or different in their dimensions and / or in their mechanical or physical characteristics.

As can be seen in the drawings, the second central upper reinforcement (22) has a length less than the length of the first upper reinforcement (6) and in particular of its horizontal wall (7).

Claims (18)

1. Ski, especially an alpine ski, having the shape of an elongated beam constituted by a core (10), a lower reinforcement (15, 16), an upper reinforcement (6, 7) and a shock absorption element (21) in the mounting zone of the bindings; said shock absorption element being arranged on said upper reinforcement (6, 7) and beneath a second central upper reinforcement (22), characterized in that the second upper reinforcement (22) is covered with a superficial cover layer (17) extending frontwardly (AV) and rearwardly (AR) to cover the first upper reinforcement (6, 7) beyond the mounting zone (18); said mounting zone (18) projecting with respect to the general plane of the ski to constitute an integrated shock absorption platform.
2. Ski according to claim 1, characterized in that superficial cover layer (17) is made of polyamide or of a thermoplastic material.
3. Ski according to any of claims 1 or 2, characterized in that the first upper reinforcement (6, 7) and the second central upper reinforcement (22) are constituted by layers of composite materials or of metallic alloy.
4. Ski according to any of claims 1 to 3, characterized in that core (10) is a synthetic foam, made of wood or of honey comb.
5. Ski according to any of the preceding claims, characterized in that shock absorption element (21) is constituted by a strip of elastically deformable material of a thickness "e" and length "X".
6. Ski according to claim 5, characterized in that shock absorption element (21) is made of viscoelastic material.
7. Ski according to claim 6, characterized in that the length "X" of shock absorption element (21) is comprised between 400 and 1000 millimeters.
8. Ski according to claim 7, characterized in that the thickness "e" of shock absorption element (21) is comprised between 0.5 and 6 millimeters.
9. Ski according to any of the preceding claims, characterized in that shock absorption element (21) is constituted of at least two independent elements (21a, 21b, 21c) of which at least one has dimensional and/or mechanical and physical characteristics different from the other.
10. Ski according to claim 9, characterized in that the shock absorption element is constituted of three independent elements (21a, 21b, 21c).
11. Ski according to claim 10, characterized in that front element (21a) and rear element (21c) are made of viscoelastic material.
12. Ski according to claim 4, characterized in that front element (21a) and rear element (21c) have a length ("La, Lc") comprised between 150 and 400 millimeters.
13. Ski according to claim 12, characterized in that front element (21a) and rear element (21c) have a shore hardness A of 70 to 90 and a shock absorption value comprised between 0.1 and 0.8, whereas median element (21b) is made of elastic material with a shore hardness A of 35 to 70.
14. Ski according to any of the preceding claims, characterized in that retention screws (24) of bindings (18, 19) are anchored both in first upper reinforcement (7) and in second central upper reinforcement (22).
15. Ski according to any of the preceding claims, characterized in that the second central upper reinforcement (22) has a length "X" smaller than the length of the first upper reinforcement.
16. Ski according to claim 15, characterized in that superficial layer (17) extends along the length of the ski.
17. Ski according to claim 16, characterized in that shock absorption element (21) is adhered or welded to the first upper reinforcement (7) and to second central upper reinforcement (22).
18. Ski, especially an alpine ski, having the shape of an elongated beam constituted by a core (10), a lower reinforcement (15, 16), an upper reinforcement (6, 7) and a strip of elastically deformable material (21) in the mounting zone of the bindings; said strip (21) being arranged on said upper reinforcement (6, 7) and beneath a second central upper reinforcement (22), characterized in that retention screws (24) of bindings (18, 19) are anchored both in first upper reinforcement (7) and in second central upper reinforcement (22).

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