EP0510308B1 - Damping device for skis - Google Patents

Abstract

Device intended for damping the vibrations of a ski, characterised in that it consists of at least one flexing blade (13) connected to the ski via a rigid linking means (15) and at least one flexible linking means (18), these said means being spaced longitudinally from one another on the said blade. <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 to this type of skis.

It is known to make the ski body thanks to a more or less flexible structure.

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 a tip, a rear part slightly raised in the 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.

Current skis have a certain number of drawbacks and in particular that of poor behavior during oscillations due to vibrations or flexing of the ski. Indeed, the persistent vibrations cause a loss of grip and therefore, poor skiing. It is therefore very important to dampen vibrations, so solutions have already been proposed. Note, for example, the solutions proposed in French patent applications Nos. 2,503,569 and 2,575,393. However, these damping devices have in fact only very minor and imperceptible effects for the skier.

Document WO-A-8801189 relates to a ski provided with attached elements making it possible to modify the pressure distribution on the ski which comprise a blade made of very rigid material connected to one end of the ski by a fixed connection and to the other end by a bracing element whose height and / or volume can be modified in order to vary the pressure exerted by the blade on the ski. The present invention seeks to remedy the various drawbacks mentioned above and proposes a particularly simple, effective and reliable solution to the problems of damping vibrations by avoiding modifying the pressure distribution on the ski.

Thus, the ski according to the present invention is provided with a device intended to dampen vibrations comprising at least one blade oriented longitudinally and connected to the ski by a rigid connection means, said blade comprising at least one free end, able to move longitudinally when the ski is flexed and being spaced longitudinally of said rigid connection means; this ski is characterized in that said free end is connected to the ski by a flexible means of damping the longitudinal shear stresses during the longitudinal displacements of said free end.

According to additional characteristics, the rigid connection means is located at the other end of said flexion blade.

According to a particular arrangement, the bending blade is an aluminum or composite material blade.

According to particular provisions, the flexion blade is fixed to the upper surface of the ski or in its structure.

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.

Figures 1 to 5 show a first embodiment.

Figure 1 is a side view.

Figure 2 is a top view.

Figure 3 is a cross-sectional view along T1.

Figure 4 is a cross-sectional view along T2.

Figure 5 is an exploded partial perspective view.

Figures 6 and 7 show two variants in top view.

FIG. 8 is a sectional view along T3 of the variant of FIG. 7.

Figures 9, 9a, 10, 10a show in side view, how the ski equipped with the device works.

Figure 9 shows the ski in the rest position, not bent.

Figure 9a shows a detail of Figure 9 on a larger scale.

Figure 10 shows the ski in the bent position.

Figure 10a shows a detail of Figure 10 on a larger scale.

Figures 11 and 12, 13 and 14, 15 and 16, 17 and 18, 19 and 20, 21 and 22 are views similar to Figures 1 and 2 showing other alternative embodiments.

FIG. 19a is a cross section along T3 of FIGS. 19 and 20.

Figures 23 and 24 are partial views on a larger scale showing in side view (Figure 23) and in top view (Figure 24) an improvement.

Figure 25 also shows in side view, another detail concerning a variant.

Figures 26 and 27 show in top view (Figure 27) and in longitudinal section along T4 (Figure 26) another embodiment.

Figure 28 is a side view showing another alternative embodiment.

Figure 29 is another side view showing a variant.

The ski (1) comprising the device consists of an elongated beam having its own distribution of thickness, of width and therefore its own stiffness. It comprises a central part (2) also called a mounting area for the bindings (3, 4) intended to retain the boot on the ski, the front binding (3) being commonly called a stop, while the rear binding (4) is called usually heel. The front end (5) of the ski (1) is raised to form the tip (6), while the rear end (7) is also raised to form the heel (8) of the ski. The beam further comprises a lower sliding surface (9) and an upper surface (10). Note that the contact of the lower surface (9) with the snow takes place between the front contact point (11) and the rear contact point (12) corresponding to the places where said lower surface begins to rise.

According to the first embodiments shown in FIGS. 1 to 25, the damping device according to the invention consists of a flexion blade (13, 13a, 13b) disposed on the upper surface (10) of the ski outside of its structure itself.

According to a characteristic of the invention, the blade is connected to the ski by rigid connection means (15, 150) and at least means for flexible connection (17, 18, 180) spaced apart longitudinally from said rigid connection means (15, 150).

FIGS. 1 to 10 show a first variant according to which the damping device is such that it is the rear end (130) of the flexion blade (13) which is fixed to the ski in the central zone (2), and extends forward (AV). The bending blade (13) is for example constituted by an aluminum strip of thickness "e₁" between 1 and 5 millimeters, of width "l₁" between 10 and 60 millimeters and of length between 100 and 1200 millimeters .. Its rear end (130) is rigidly fixed to the ski at the stop (3) by rigid connection means. Thus, the rear end (130) of the aluminum strip is for example arranged under the base plate (14) of the fixing (3) and retained with it by the screws (15). For this purpose, the end (130) of the strip ends in an enlarged part (130 ') comprising holes (16) allowing the passage of the fixing screws (15). According to the invention, the front end (131) of the flexion blade (13) is linked to the upper surface of the ski by damping means (17) constituting the flexible connection means. Thus, there is disposed between the front end (131) of the flexion blade (13) and the ski, an interface (18) produced by a layer of a flexible material of the elastic type and in particular of the viscoelastic type. This layer of thickness "e₂" of between 0.5 and 4 millimeters is glued or welded on the one hand under the lower surface (132) of the blade and on the other hand on the upper surface (10) of said ski (1 ). It can have the same width "l2" as the width "l₁" of the blade and a length "L₂" of between 2 and 15 centimeters. It will be noted that the rigid connection means (15) are spaced longitudinally by a distance "D" from the flexible connection means (17).

The material used can be elastic with a density of 10 to 85 shores A or a viscoelastic material with a modulus of elasticity of 15 to 160 megapascals, a hardness of 50 to 95 shores A and a damping value of 0.13 to 0.72. Of course, these data are only exemplary embodiments, for a temperature of 20 degrees and a frequency of 15 Herz. The interface (18) is fixed on the blade (13) and on the upper surface of the ski either by a thermosetting resin of the epoxy poylester, vinylester or polyurethane type, or by a thermoplastic film or any other means. Of course, it is possible to fix the rear end (130) of the blade independently and independently of the stop (3), as shown in Figures 6 and 7. In Figure 6, the blade is fixed in front the stop, while in Figure 7, it is fixed behind. In this case, the blade (13) passes freely under the base plate (14) of said stop (see Figure 8). To this end, the lower surface of the base plate includes a hollow profile (140) whose dimensions are greater than the dimensions of the blade (13) to allow passage and free movement. The blade is then fixed directly to the ski by screws (150) in the area between the front binding (3) and the rear binding (4).

It is also possible to fix the flexion blade (13) to the upper surface (10) of the ski (1) by gluing or welding.

Figures 9, 9a, 10, 10a schematically show the operation of depreciation. Figure 9 shows the ski in the rest state and Figure 10, during bending. At rest, the point "a" of the front end (131) of the flexion blade corresponds to a point "b" of the upper surface (10) of the ski. During bending (FIG. 10), it is noted that there is a relative longitudinal displacement (d) between the points "a" and "b". During this displacement, there is shearing of the layer of flexible material and therefore damping. The choice of interface material and its dimensions determining the depreciation conditions.

Of course, the damping device can be arranged at the rear of the ski, as shown in FIGS. 11 and 12. Thus according to this variant, the flexion blade (13) is fixed to the ski rigidly by its end front (131) and extends rearward. The rear end (130) of the blade being linked to the ski by damping means (17) constituted as before by an interface (18) made of flexible material.

It goes without saying that the ski can comprise both a front bending blade (13a) and a rear bending blade (13b), as shown in FIGS. 13 and 14.

Figures 15 and 16 show another embodiment according to which the flexion blade (13) is fixed to the front of the ski by its front end (131) by means of screws (150). The blade (13) then extending rearward and its rear end (130) is linked to the ski and more precisely at its upper surface (10) by damping means (17) which are identical to those described above, that is to say by a bonded interface (18) made of flexible material.

Figures 17 and 18 show another variant in which the blade (13) is fixed to the rear of the ski by screws (150) and extends forward to be connected to the ski by an interface (18) in an area behind the heel.

It goes without saying that in the embodiments of FIGS. 15 to 18, the bending blades can be more or less long.

Thus, the blade (13) of Figure 19 is freely engaged under the stop (3) to extend beyond the latter, to be linked elastically to the ski. For this purpose, the base plate (14) comprises a hollow profile (140) whose dimensions allow the passage and the free movement of the bending blade (13).

Figures 21 to 24 show a variant in which there is a multiplication of longitudinal effects due to the flexing of the ski. To this end, the ski comprises two flexion blades (13a, 13b): a first front flexion blade (13a) and a second rear flexion blade (13b). The front flexion blade (13a) is fixed to the ski in front of the stop (3) by its front end (131a) by means of screws (150) and extends backwards passing freely under said stop (3). Likewise, the rear flexion blade (13b) is fixed to the ski behind the heel piece (4) by its rear end (130b) to extend forwards, passing freely under said heel piece (4) as far as the central zone. (2) between the two fixings (3, 4). It is noted that there is overlap of the two ends. The rear end (130a) of the first blade (13a) being engaged under the front end (131b) of the second blade (13b). The covering is done over a length "l₃".

In this variant, the damping means consist of an interface (18) constituted by a layer of flexible or viscoelastic material, as above, but disposed not on the ski, but between the two blades in their overlap zone. Thus, the rear ends (130a) of the first blade (13a) and the front (131b) of the second blade (13b) are not at all linked to the ski.

To avoid any lifting of the ends (130a and 131b) of the bending blades (13a and 13b), it is possible to provide a vertical retainer, such as a screw (19) housed in an oblong hole (190) produced in the stack of the two ends (130a and 131b) and of the damping layer, as shown in FIGS. 23 and 24. The vertical restraint could also be achieved by an inverted U-shaped bracket or any other means.

Another variant is shown in FIG. 25 where a second damping layer (180) is glued under the rear end (130a) of the first blade (13a) and to the upper surface of the ski (10).

In the various embodiments proposed in FIGS. 1 to 25, the damping device is arranged outside the structure proper of the ski. However, of course, it would not go beyond the scope of the invention if it were arranged in the structure of the ski itself, as shown schematically in FIGS. 26 and 27.

The skis most often consist of a core (101) covered by one or more layers of upper reinforcement (102), or even lower (103). The top of the ski is generally covered by a layer of decorations (104), while the bottom comprises a sliding layer of polyethylene (105).

The bending blade, in the example shown, is fixed under the upper reinforcement (102) and takes place in a housing (106) produced in the core. It goes without saying that it would not go beyond the scope of the invention whatever the place of the damping device. Indeed, the bending blade could be between the core (101) and the lower reinforcement (103) or even between the upper reinforcement (102) and the surface layer (104).

It should be noted that the bending blade shown and described above has a constant cross section, but it could be otherwise. Thus, the section of the blade, in a cross section can be variable. Indeed, the width can vary, as well as the thickness. The shape of the profile which, in the embodiments shown, is rectangular, could be trapezoidal and vary along its length.

FIG. 28 represents another variant in side view according to which the damping device is constituted by a blade (13c) fixed in its central part (132) and whose front (131) and rear (130) ends are elastically connected to the ski (1).

FIG. 29 shows a variant according to which the blades (13c) and (13b) linked elastically together in the central zone (2) of the ski are fixed at their ends by the corresponding ski bindings (3 and 4).

Claims (17)

1. Ski equipped with a device intended to damp vibrations, comprising at least one blade (13, 13a, 13b, 13c) oriented longitudinally and connected to the ski by a rigid linkage means (15, 150), said blade (13, 13a, 13b, 13c) comprising at least one free end (130, 130a, 131, 131b), adapted to be displaced longitudinally when the ski is biased in flexion, and being spaced longitudinally from said rigid linkage means (15, 150); characterized in that said free end is connected to the ski by a flexible means (17, 18, 180) for damping longitudinal shearing biases during longitudinal displacements of said free end.
2. Ski according to claim 1, characterized in that the rigid linkage means (15, 150) is located at the other end of said flexion blade (13, 13a, 13b, 13c).
3. Ski according to any of the preceding claims, characterized in that the flexion blade (13, 13a, 13b, 13c) is an aluminum blade.
4. Ski according to claim 1 or 2, characterized in that the flexion blade (13, 13a, 13b, 13c) is made of a composite material.
5. Ski according to any of the preceding claims, characterized in that the flexion blade has a width "l₁" comprised between 10 and 60 millimeters, a thickness "e₁" comprised between 1 and 5 millimeters and a length "L₁" comprised between 10 and 1200 millimeters.
6. Ski according to claim 5, characterized in that the flexible linkage means (18, 180) are constituted by an interface made of a flexible material arranged between said flexion blade (13, 13a, 13b, 13c) and the ski.
7. Ski according to claim 6, characterized in that the interface (18, 180) is a layer of an elastic or viscoelastic material welded or adhered to the end of the flexible blade (13, 13a, 13b, 13c) on the one hand, and to the ski, on the other hand.
8. Ski according to claim 7, characterized in that the layer of viscoelastic material has a width "l₂" comprised between 10 and 60 millimeters, a thickness "e₂" comprised between 0.5 and 4 millimeters and a length "L₂" comprised between 2 and 15 centimeters.
9. Ski according to any of the preceding claims, characterized in that the flexion blade (13, 13a, 13b, 13c) is arranged and fixed at the upper surface (10) of the ski (1).
10. Ski according to claim 9, characterized in that the flexion blade (13, 13a, 13b, 13c) is arranged in the structure of the ski (1).
11. Ski according to any of claims 9 or 10, characterized in that the flexible blade (13) extends between the central mounting zone (2) of the bindings (3, 4) and the front contact point (11).
12. Ski according to any of claims 9 or 10, characterized in that the flexible blade (13) extends between the central mounting zone (2) of the bindings (3, 4) and the rear contact point (12).
13. Ski according to any of claims 9 or 10, characterized in that the flexion blade (13, 13a, 13b, 13c) extends along both the central mounting zone (2) of the bindings and the zone located between said central zone (2) and the front contact point (11).
14. Ski according to any of claims 9 or 10, characterized in that the flexion blade (13, 13a, 13b, 13c) extends along both the central mounting zone (2) of the bindings and the zone located between said central zone (2) and the rear contact point (12).
15. Ski according to any of claims 11 to 14, characterized in that the flexion blade (13, 13a, 13b, 13c) is rigidly fixed to the ski by its rear end (130), whereas its front end (131) is connected to the ski by a flexible shock absorption linkage (17, 18).
16. Ski according to any of claims 11 to 14, characterized in that the flexion blade (13, 13a, 13b, 13c) is rigidly fixed to the ski by its front end (131), whereas its rear end (130) is connected to the ski by a flexible shock absorption linkage (17, 18).
17. Ski according to claims 15 and 16, characterized in that it comprises two flexion blades, a front flexion blade (13a) whose front end (131a) is fixed to the front of the ski and extends rearwardly, a rear flexion blade (13b) whose rear end (130b) is fixed to the rear of the ski to extend frontwardly, the rear end (130a) of the front blade (13a), and the front end (131b) of the rear blade (13b) overlapping in the central zone (2) and being connected to one another by an elastic linkage (18).

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