EP0609543B1 - Ski with a damping device - Google Patents

Abstract

Damping device for damping the vibrations of a ski and comprising a flexion blade (15) intended to be connected to the ski, characterised in that it comprises at least two damping means (M1, M2) via which the said blade is intended to be connected to the ski in a movable manner, the said damping means (M1, M2) being connected via the said flexion blade so as to be spaced longitudinally by a certain distance. <IMAGE>

Description

The present invention relates to a ski such as an alpine ski, a cross-country ski background, a monoski or a snowboard. It relates more particularly to a ski equipped with a vibration damping device.

We already know different types of skis made thanks to a structure more or less flexible. There are many variations, which are formed by 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 are combined different materials so that each of them intervenes optimally, taking into account the distribution of constraints mechanical when using the ski. So the structure includes generally peripheral protective elements, internal elements of resistance to resist bending and torsional stresses, and a core. These elements are assembled by gluing or injection, the assembly being carried out generally hot in a mold having the final shape of the ski, with a front part strongly raised with a spatula, a rear part slightly raised in heel, arched central part.

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

Current skis have a number of disadvantages and particular, that of having a bad behavior during the oscillations due vibration or flexing of the ski. Indeed, the persistent vibrations cause a loss of grip and therefore poor ski handling. It is therefore very important to dampen vibrations in good conditions, so it has solutions have already been proposed. Let us note for example the solutions proposed in French patent applications 2,503,569 and 2,575,393. But these devices depreciation actually have only very minor and imperceptible effects for the skier.

The document EP-A-0 490 044 is a ski provided with a stiffener connected to a base flexibly by two remote flexible interfaces, one of the other. The stiffener is used to complete the stiffness of the base without any effect depreciation is sought per se.

The present invention seeks to remedy the various drawbacks mentioned above and offers a particularly simple, effective solution and reliable to vibration damping problems, by combining the advantages of local vibration dissipation through deformation minimal, and offset by taking advantage of the displacement much more important. The device of the invention also does not provide stiffness too much additional local skiing.

Thus, the ski equipped with a damping device of the type includes a bending piece connected to the ski by damping means. The bending piece is a flexible bending blade whose stiffness is negligible compared to the ski itself and which is connected to the ski mobile way, by at least two damping means each forming a flexible connection means of the flexion blade on the ski, constituted by a soft material interface subjected to shear during relative movement of the bending blade with respect to the ski; said damping means being spaced longitudinally by a certain distance "D"; the first way being located in the zone of maximum deformation by the third bending mode and the first mode of torsion or in the zone of maximum deformation by the second flexion mode and the second means being located in the area of maximum deformation by the first bending mode.

According to an additional characteristic, the bending blade is a blade, a profile or a metal rod, made of aluminum or steel, or made of composite material. It has a section between 5 and 300 mm ² . Its length is between 100 and 1,200 millimeters. It should be noted that the blade is flexible in bending and does not generate static, additional bending stiffness (that is to say that the stiffness is negligible compared to the rest of the ski).

Other characteristics and advantages of the invention will emerge from the description which will follow with regard to the appended drawings which are not given as non-limiting examples.

Figures 1 to 3 show a first embodiment of the invention.

Figure 1 is a side view, Figures 1a and 1b illustrating details of construction.

Figure 2 is a top view.

Figure 3 is a side view of the ski in the flex position, the figures 3a and 3b illustrating operating details.

Figures 4 and 5 show another embodiment, Figure 4 being a partial top view, while FIG. 5 is a partial view back in perspective.

Figures 6 and 7 show a variant of the invention, Figure 6 being a side view of FIG. 7 being a top view.

Figures 8 to 10 illustrate an alternative embodiment, Figure 8 being a side view, Figure 9 being a top view, while Figure 10 is a sectional view along X-X.

Figure 11 is a side view according to a variant of the invention.

Figure 12 is a sectional view of a detail according to a mode particular.

Figures 13 and 14 are views from above and respectively the axis (A, AO) of a surfboard equipped with the device according to the invention.

The damping device (1) according to the invention is intended to be connected to a ski with the general reference (2). Said ski being known per se, it does not will not be described in detail. However, remember that it consists of a elongated beam (3) having its own distribution of thickness and width, therefore its own stiffness. It includes a central part (4) also called mounting the bindings (5, 6) intended to retain the boot on the ski, the binding front (5) being commonly known as a stop, while the rear fixing (6) is generally called heel. The front end (7) of the ski (2) is raised to form the spatula (8), while the rear end (9) is also to form the heel (10) of the ski. The beam also comprises a lower surface of sliding (11) and an upper surface (12). Note that the contact of the surface lower (11) with snow is between the front contact point (13) and the point rear contact (14) corresponding to the places where said lower surface starts to get up.

Said damping device bearing the general reference (1) is consisting of a bending blade (15). The latter is for example constituted by an aluminum strip of thickness "e" between 1 and 5 millimeters, of width "l" between 10 and 60 millimeters and a length "L" included between 100 and 1,200 millimeters. According to the invention, the bending blade (15) is connected to ski movably longitudinally by damping means, so as to be able to move completely and over its entire length relative to the ski. To this end, the first connection zone (16) of said flexion blade (15) is connected skiing by first connecting means (M1), while the second zone of connection (17) of said blade (15) is connected to the ski by two second means of connection (M2). According to one of the characteristics of the invention, the second zone of link (17) is spaced longitudinally from the first link area (16) of an average distance (D), while the first (M1) and the second (M2) connecting means are also damping means.

In the configuration illustrated in FIGS. 1 to 5 and in FIGS. 11 to 14, the damping device is, for example, disposed at the front of the ski; so, the bending blade (15) extends longitudinally over a length "L" between the front stop (5) and the front contact point (13).

Figures 1 to 3 illustrate a first embodiment according to which the two connecting means (M1, M2) are flexible. Thus, the front end constituting the first connection zone (16) of the flexion blade (15), is linked to the upper surface of the ski by a first damping means (M1) constituting the flexible connection means. Thus, there is disposed between the front end (16) of the flexion blade (15) 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 "e1" is glued or welded on the one hand under the lower surface (19) of the blade, and on the other hand on the upper surface (12) of said ski (2). It can for example have the same width as the width "l" of the blade and a length "L1" of between 2 and 15 centimeters. The surface of the layer is between 200 and 6000 mm ² . The shape of the layer can be rectangular, but can take any other form. The first interface (18) is fixed under the blade (15) and on the upper surface (12) of the ski, either by a thermosetting resin of the polyester, vinylester or polyurethane epoxy type, or by a thermoplastic film or any other means. .

Likewise, the rear end constituting the second connection zone (17) of the flexion blade (15) is connected to the ski by a second damping means (M2) similar to the first means. Thus, there is disposed between the rear end (17) of the flexion blade (15) and the ski, an interface (20) produced by a layer of a flexible material of the elastic type and in particular of the viscoelastic type. This layer of thickness "e2" is glued or welded on the one hand under the lower surface (19) of the blade, and on the other hand on the upper surface (12) of said ski (2). The surface of the layer is between 200 and 6000 mm ² . The shape of the layer can be rectangular, but can take any other form. The interface (20) is fixed under the blade (15) and on the upper surface of the ski, either by a thermosetting resin of the polyester, vinylester or polyurethane epoxy type, or by a thermoplastic film or any other means.

Figures 1, 1a, 1b, 3, 3a and 3b schematically illustrate the how depreciation works. Figures 1, 1a and 1b show the ski in the state rest. In this resting situation, point "a1" of the front end (16) of the blade corresponds to point "b1" of the upper surface of the ski. During bending (Figures 3, 3a, 3b), the bending blade (15) moves longitudinally by compared to the upper surface of the ski and we see that the point "a1" has moved forward, a distance "d1" from point "b1", while the point "a2" has moved backwards relative to the corresponding point "b2", from a distance "d2". During this displacement, there is shearing of the layers of flexible material, and therefore damping. The choice of interface material and of its dimensions determines the depreciation conditions.

The two interfaces (18) and (20) could be strictly identical, but they can advantageously be different. They could by example have different dimensions and / or be made of a material different. Thus, the thickness "e2" of the second interface (20) could be different, and for example greater than the thickness "e1" of the first interface (18), as illustrated in FIGS. 1 to 3. Similarly, the first interface (18) could be of harder material than the material of the second interface (20).

According to a characteristic of the invention, the first interface (18) which is located in the area where there is a maximum of deformation energy by the third mode of bending and the first mode of torsion, must therefore dissipate these two types of vibration, and it can, for this purpose, be made of a material viscoelastic with a hardness of around 60 Shores A and having a thickness about 0.5 millimeters. Similarly, the second interface (20) which is located in rear near the central area (2) of the ski, must dissipate the first bending mode and it can be made of a viscoelastic material of lower hardness at 20 Shores A and have a thickness of 4 millimeters.

According to another characteristic of the invention, the first interface (18) is located in the area where there is a maximum of deformation energy by the second flexion mode, and the second interface (20) which is located in rear near the central area (2) should dissipate the first bending mode. The bending blade (15) constituting a connecting element between the two interfaces (18, 20), making it possible to obtain a relative displacement relative to the ski, more important from the rear end (17) thereof, as illustrated in Figures 3, 3a and 3b, where the displacement "d2" is greater than the displacement "d1".

Of course, the bending blade can take any desired shape and in particular that which is illustrated by way of example, in FIGS. 4 and 5. In this variant, the blade (15) is in the form of a profile having a rib central extending over a certain length of the blade, so as to avoid buckling of the blade. At the front end of the blade, an enlarged area (160) is linked to the ski surface by a front interface (180). The blade or profile can be produced by injection in charged plastic material. The modulus of the material as well that the section of the blade is chosen so as to obtain the stiffness in compression wanted. When using high modulus materials, such as steel or carbon, the blade can be replaced by a simple cylindrical rod or rectangular of small section, so as not to exceed values in too much compression.

It goes without saying that the damping device (1) can be arranged on the ski, other than on the front, and in particular be arranged at the rear of the ski, as this is shown in Figures 6 and 7 where elements similar to the mode of previous production, have the same references. So everything that has been described for the device placed at the front, illustrated in Figures 1 to 5, is valid for the device placed at the back.

It goes without saying also that the bending blade could extend as far as the central zone (4) of the ski, as shown in FIGS. 8 to 10. In this case, the bending blade (15) passes freely under the base plate (21) of the stop, the underside of which comprises a hollow profile (22) whose dimensions are larger than the dimensions of said blade (15), to allow passage and free movement.

In the embodiment described above, the two means of connection and damping (M1, M2) are made by a layer of material viscoelastic bonded to both the blade and the ski by bonding or welding, so that the damping is obtained by the shearing of the elastic layer.

FIG. 11 illustrates a particular mode where a third means damping (M3) is arranged between modes (M1) and (M2), respectively mean distance "D1" from (M1) and "D2" from (M2). The means (M3) can be of everything type, as described above, i.e. type with flexible interface, dry or viscous friction.

FIG. 12 illustrates the case of a device integrated into the structure of the ski. In particular, the ski is provided with a longitudinal internal housing (40) and allows the blade to move freely when the ski is stressed. Housing is covered with an internal reinforcing layer (41) and a protective top and decoration (42).

Figures 13 and 14 illustrate the use of the device of the invention on a snowboard (43). In this particular case, it may be advantageous orient the device along an axis (AA ') which has a certain angle (α) by relative to the median longitudinal axis (BB ') of the surf. In fact, unlike a ski alpine, the surf is used asymmetrically, the surfer adopts a position of conduct which causes it to exert efforts towards the toes (in "front side") and in the direction of the heels (in "back side") along an axis (CC ') substantially corresponding to the axis of symmetry of the fasteners (44, 45). So, he may be advantageous to orient the device more or less by an angle (α) by relative to the median longitudinal axis (BB ') of the surf. It goes without saying that the device could have another provision and in particular that illustrated in fine lines interrupted. According to this arrangement, the bending blade (15 ') is not in the axis (BB ') of the snowboard (43) and extends substantially parallel to this axis.

Of course, the invention is not limited to the embodiments thus described and shown as examples, but it also includes all of the technical equivalents and their combinations within the scope of the claims.

Claims (9)

1. Ski equipped with a shock absorbing device of the type comprising a flexion element connected to the ski by shock absorbing means, the flexion element being a flexible flexion blade (15) whose stiffness is negligible with respect to the ski itself, and being movably connected to the ski by at least two shock absorbing means (111, 112) each forming a flexible linkage means of the flexion blade on the ski (18, 20), constituted by an interface made of a flexible material stressed in shearing during the relative displacement of the flexion blade with respect to the ski; said shock absorbing means being longitudinally spaced apart by a certain distance

   

   D

   

   ; the first means (111) being located in the zone of maximum deformation by the third flexional mode and the first torsional mode or in the zone of maximum deformation by the second flexional mode, and the second means (112) being located in the zone of maximum deformation by the first flexional mode.
2. Ski equipped with a shock absorbing device according to claim 1, characterized in that the flexion blade (15) is a blade, a section, or a rod made of metal aluminum, steel or composite material.
3. Ski equipped with a shock absorbing device according to claim 2, characterized in that the flexion blade has a width (l) comprised between 10 and 60 millimeters, a thickness (e) comprised between 1 and 5 millimeters, and a length (L) comprised between 100 and 1,200 millimeters.
4. Ski equipped with a shock absorbing device according to claim 1, 2, or 3, characterized in that the interface (18) is a layer of viscoelastic material welded or adhered to the flexion blade (15).
5. Ski equipped with a shock absorbing device according to claim 4, characterized in that the layer of viscoelastic material has an area comprised between 200 and 6,000 mm² and a thickness e1" comprised between 0,5 and 4 millimeters.
6. Ski equipped with a shock absorbing device according to any of the preceding claims, characterized in that the blade (15) is connected by a third shock absorbing means (M3) arranged between the two means (M1, M2).
7. Ski equipped with a shock absorbing device according to any of the preceding claims, characterized in that the flexion blade (15) is arranged and fixed at the upper surface (12) of the ski.
8. Ski equipped with a shock absorbing device according to any of claims 1-6, characterized in that the flexion blade (15) is arranged in the ski structure.
9. Ski equipped with a shock absorbing device according to any of the preceding claims, characterized in that this ski is an alpine ski.

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