EP0521272A1 - Improvements in damping devices for skis - Google Patents

Abstract

Damping device intended to dampen the vibrations of a ski, characterised in that it consists of at least one flexing blade which comprises a first part fixed to the ski and a second part connected to the ski in a longitudinally movable manner via friction means. <IMAGE>

Description

The present invention relates to a damping device for skiing, such as an alpine ski, a cross-country ski, a monoski or a snowboard. It relates more particularly to an improvement of this type of device, and also relates to a ski equipped with it.

It is known to make the body of the ski 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, the front end of which 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 protective 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.

Current skis have a 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 handling of the ski. It is therefore very important to dampen vibrations, so solutions have already been proposed. Let us note for example the solutions proposed in the French patent applications n ° 2 503 569 and 2,575,393. However, these damping devices have in fact only very minor and imperceptible effects for the skier.

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.

To this end, the damping device according to the invention and intended to damp the vibrations of a ski, is characterized in that it is constituted by at least one bending blade or the like, which comprises a first part rigidly fixed to the ski and a second part connected to said ski movably longitudinally by friction means.

According to an additional characteristic, the second part is spaced longitudinally from the first part, this in order to amplify the relative longitudinal displacements of the second part of the blade relative to the ski.

According to an advantageous arrangement, the friction means comprise at least one friction layer and a pressure member, to make efficient energy dissipation by friction. The friction layer can either be bonded to the flexion blade, or bonded to the ski, or else bonded to the pressure member.

According to one embodiment, the pressure member is a fixed part fixed to the ski.

According to other embodiments, the pressure member is constituted by the base plate of the binding intended to retain the ski boot, or a movable part on which the ski boot rests.

The bending blade is a metal, aluminum or steel blade, or a composite material. It is of rectangular cross section, and can be constituted by a rod of circular section.

The invention also relates to the ski equipped with the device according to the invention which can be either outside its structure, or in this 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 6 show a first embodiment.

Figure 1 is a side view.

Figure 2 is a top view.

Figure 3 is a cross section along T1, on a larger scale.

Figure 4 is a longitudinal section along L1, on a larger scale.

FIGS. 5 and 6 show in side view how the device works, FIGS. 5a and 6a being partial representations on a larger scale of FIGS. 5 and 6.

Figure 7 is a view similar to Figure 3 showing a variant.

FIGS. 8 and 8a represent a variant, FIG. 8a being a cross section along T2 of FIG. 8.

Figure 9 is a partial side view showing another alternative embodiment.

Figures 10 and 11 are views similar to Figures 1 and 2 showing another embodiment.

Figures 12 and 13 show an alternative embodiment, Figure 12 being a side view, while Figure 13 is a cross section along T3.

FIG. 14 is a view similar to FIG. 13 showing another embodiment of FIG. 13.

Figures 15 and 16 show in detail another variant of the friction means, Figure 15 being a partial side view and partially in longitudinal section along L2, while Figure 16 is a cross section along T4.

Figure 17 is a cross-sectional view of a ski in which the damping device is embedded.

Figures 18 to 20 illustrate an alternative embodiment, Figure 18 being a side view, while Figure 19 is a cross section along T5 and T7, and Figure 20, a cross section along T6. FIG. 19 is also a section along T5 and T7 in FIG. 22.

Figure 21 is a schematic side view of another variant.

Figures 22 and 23 show another embodiment.

Figure 22 is a side view.

FIG. 23 is a sectional view along T8 and T9 of FIG. 22.

Figures 24 and 25 are views similar to Figure 4 showing alternative embodiments.

The ski (1) comprising the device consists of an elongated beam (100) 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 generally 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.

Figures 1 to 6 show a first embodiment according to which the damping device according to the invention consists of a bending blade (13) disposed at the front on the upper surface (10) of the ski (1). According to the invention, said flexion blade is fixed to the ski by a first part constituted by the rear end (131) of the blade, while it is connected to it by a second part, by friction means (14) . The fixing of the first part (131) of the blade on the ski is a fixed, rigid connection, produced for example by screws, by gluing or by welding. According to this embodiment, the second part is constituted by the front end (130) of the flexion blade (13) which is movable longitudinally relative to the ski, and is connected to it by friction means (14), which consist of two layers (140, 141) of material with a high, dry coefficient of friction and a retaining and supporting stirrup (142). The dry, high friction material may consist, for example, of a layer of thermoplastic rubber or of viscoelastic material. Thus, a first layer (140) of rubber is bonded to the upper surface (10) of the ski, while a second layer (141) is bonded under the central wall (143) of the retaining stirrup which has the shape an Ω (omega) and which is fixed to the ski by screws (15). The front end (130) of the bending blade can thus be move along F1 and F2 between the first layer and the second layer of rubber. So that there is dissipation of the energy of the longitudinal movements along F1 and F2 of the end (130) of the blade, the stirrup maintains a pressure and clamps the blade between the two layers. For this purpose, the height (h) of the lower housing (144) of the stirrup is slightly less than the sum of the thicknesses of the blade and of the two layers when these are at rest, not pinched by the stirrup.

Of course, the intensity or the clamping force of the bending blade between the two friction layers can be adjustable as a function of the damping which it is desired to obtain.

Figure 7 is a view similar to Figure 3, showing an embodiment of the means for adjusting the clamping force, and therefore the intensity of friction. According to this variant, the stirrup (142) is not supported on the upper surface (10) of the ski (100), but supported on an elastic intermediate layer (140i). Thus, the value of the tightening of the screws (14) defines the force of the tightening of the blade (13) between the two layers (140, 141) by variation of the thickness (e4).

Figures 5, 5a, 6 and 6a schematically show the operation of depreciation. Figure 5 shows the ski in the rest state, and Figure 6, during bending. During bending, it is noted that there is relative displacement towards the front of the front end (130) of the blade relative to the friction means (14). According to the schematic representation, the front end has moved forward along F1 over a distance (d) and this movement has been braked by the friction layers (140,141).

It goes without saying that the bending blade can be longer or shorter and for example be as shown in FIG. 8. According to this variant, the blade (13) passes freely under the base plate (17) of the stop (3 ) which comprises a lower housing (18) whose dimensions are greater than the dimensions of the blade to allow passage and free movement. The blade then being fixed by its rear end (131) in the central zone (2) between the front fixing (3) and the rear fixing (4).

FIG. 9 represents another embodiment according to which the front end (130) of the blade is rigidly fixed on the ski, while the rear end (131) is slidably mounted in the friction means (14).

Of course, the damping device according to the invention such as that described above, can be arranged at the rear of the ski as it appears in Figures 10 and 11. Thus the front end (130) of the blade (13) is fixed to the ski and extends rearwards so that its rear end (131) is linked to the ski movably longitudinally by the friction means (14).

The friction means comprise means for pressurizing necessary for friction. These means can be constituted by a pressure member such as the bracket described above and shown in Figures 1 to 11, but also by any other device or member. Thus, the friction means can be arranged under one of the bindings, the mounting of these on the ski ensuring the necessary pressurization and thus constituting the pressure members. Figures 12 and 13 show such an arrangement.

According to this variant, the flexion blade is fixed to the ski by its front end (130), while its rear end (131) is retained by the friction means arranged under the front fixing (3) by a mounting which is see more precisely in Figure 13. As in the previous embodiments, the bending blade (13) is pinched between two layers of friction material (140, 141). Thus, the lower layer (140) bonded to the ski is formed by a part having a U-shaped profile, while the upper layer (141) is bonded under the base plate (17) of the stop (3). It is the more or less important tightening of the screws (170) which will ensure a more or less significant friction.

Figure 14 is a view similar to Figure 13 showing a variant in which the tightening is no longer a function of the intensity of screwing of the screws (170), but only the thickness dimensions of the different elements. Also, lateral spacers (154) are provided in rigid material ensuring rigid support of the base plate and a defined thickness (E).

Note that the friction pressure can be variable and for example a function of the bearing force of the ski boot (20). According to this new embodiment shown in Figures 15 and 16, the stop (3) comprises a support piece (21) for the shoe which is mounted movable around a transverse axis (22), under which one of the friction layers (141) is bonded, while the other layer (140) is bonded to the upper surface (10) of the ski. The rear end (131) of the blade (13) can thus move longitudinally between the two friction layers (140, 141). This movement being more or less braked depending on the value of the force (F) applied by the shoe on the support plate (21). Note that the fixing (3) with its movable support plate (21) was the subject of a French patent application No. 82.20852 filed by the applicant.

In the various embodiments proposed in FIGS. 1 to 16, the damping device is arranged outside the structure proper of the ski. However, it would of course not depart from the scope of the invention if it were arranged in the very structure of the ski, as shown schematically in FIGS. 17.

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). Thus in the embodiment of FIG. 17, the damping device is embedded in the ski and an upper plate (106) ensures both the pressure necessary for friction, and both the tightness of said device by completely isolating it from the outside.

In the previously proposed solution, the friction layers are bonded to the ski and to the friction part. However, it could be quite different, and the friction interfaces (140, 141) could be linked to the blade for rubbing on the ski and / or on the pressure piece (142, 17, 21). In addition, the friction layers (140, 141) which extend only on the end of the blade, in the embodiments shown, could just as well extend over a greater length, or even over any the length of said blade.

Note also that one could make a combination of damping by friction, with damping by shearing, as described in French patent application No. 91.05421. Figures 18 to 20 show such a variant in which the ski comprises a first front blade (13a) and a second rear blade (13b). The front blade (13a) being fixed to the ski by its end front, while the rear blade (13b) is by its rear end. The two blades extending towards the central zone (2) to overlap each other and be linked together by a layer (145) of viscoelastic material. The damping by friction being of course also carried out as according to the embodiments of Figures 12, 13 and 14 or the like. FIG. 19 shows such an embodiment according to which the flexion blades (13a, 13b) are clamped in their middle part (132) between a layer of friction material (142) and the upper surface of the ski thanks respectively to the pressure provided by the base plate of the stop (3) and the heel piece (4).

FIG. 21 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 linked to the ski (1) by friction means (14).

The bending blade (13, 13a, 13b, 13c) is a steel, aluminum or composite material blade whose width (l₁) is between 10 and 60 millimeters, its thickness (e₁) between 1 and 5 millimeters , and its length (L₁), between 200 and 1200 millimeters.

FIGS. 22 and 23 represent another embodiment according to which the flexion blade (13) is fixed to the ski by its front end (130) while it is, by its middle part (132) and its rear part ( 131), retained in skiing by friction means, such as those described for the production of FIGS. 18 and 19. Thus FIG. 19 is also a sectional view along T5 and T7 of FIG. 21. Furthermore, to avoid the buckling of the bending blade, the device comprises means for preventing buckling which are constituted by retaining stirrups (164) fixed to the ski and comprising a lower housing (165) allowing the blade to pass, its longitudinal movement, but holding it vertically to prevent it from moving up. Thus between said lower housing and the blade, a small operating clearance (j) is provided.

To avoid any longitudinal displacement of the friction layers (140, 141), these can be embedded at least partially in their respective support part, as shown in FIG. 24 which is a view similar to FIG. 4.

Figure 25 is another view similar to Figure 4 showing another embodiment in which the friction layer lower (140) is glued to the ski, while the upper layer (141) is glued under the blade to bear on said lower friction layer.

It goes without saying that the bending blade which, in the proposed embodiments, has a rectangular section, can take any type of shape. It can for example be constituted by a cylindrical rod.

Furthermore, it should be noted that the material constituting the friction layers is chosen as a function of the damping performance to be obtained, and for example as a function of the type of ski, or type of use.

Of course, the damping device may not include a friction layer. Indeed, the flexion blade could just as well rub directly on the ski, the surface of which could be more or less rough, granulated or striated.

It should be noted that the damping device could be covered with an external envelope serving both as a sealing part and as a decoration part. This outer envelope could moreover serve as a stirrup (142) or as a retaining part preventing the blade from buckling.

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 and their combinations.

Claims (24)

Damping device intended to dampen the vibrations of a ski, characterized in that it consists of at least one bending blade (13, 13a, 13b, 13c) which comprises a first part (131, 130, 132) fixed to the ski and a second part (130, 131) connected to the ski movably longitudinally by friction means (14). Damping device according to claim 1, characterized in that the second part (130, 131) is spaced longitudinally of the first part (130, 131, 132) by a distance (D). Damping device according to claim 1 or 2, characterized in that the friction means (14) comprise at least one friction layer (140, 141) and a pressure member (142, 17, 21, 106). Damping device according to claim 3, characterized in that the friction layer (140, 141) is bonded to the flexure blade (13). Damping device according to claim 3, characterized in that the friction layer (140) is bonded to the ski. Damping device according to claim 3, characterized in that the friction layer (141) is bonded to the pressure member (142, 17, 21, 106). Damping device according to any one of the preceding claims, characterized in that the pressure member is a fixed part (142, 106, 17) fixed to the ski. Damping device according to claim 7, characterized in that the fixed part is a stirrup (14) fixed to the ski. Damping device according to claim 7, characterized in that the fixed part is constituted by the base plate (17) of the binding (3,4) intended to retain the ski boot (20). Damping device according to any one of Claims 1 to 6, characterized in that the pressure member is a moving part (21) on which the ski boot (20) rests. Damping device according to any one of the preceding claims, characterized in that the flexion blade (13, 13a, 13b, 13c) is a metal, aluminum or steel blade. Damping device according to any one of Claims 1 to 10, characterized in that the flexure blade (13, 13a, 13b, 13c) is made of composite material. Damping device according to any one of Claims 11 to 12, characterized in that the flexure blade has a width (l₁) of between 10 and 60 millimeters, a thickness (e₁) of between 1 and 5 millimeters and a length (L₁), between 10 and 1200 millimeters. Damping device according to any one of the preceding claims, characterized in that the friction layer (140, 141) consists of elastic or viscoelastic material. Ski equipped with the device according to any one of the preceding claims. Ski according to claim 15, characterized in that the flexion blade (13, 13a, 13b, 13c) is arranged and fixed to the upper surface (10) of the ski. Ski equipped with the device according to claim 15, characterized in that the flexion blade (13, 13a, 13b, 13c) is arranged in the structure of the ski. Ski according to any one of claims 16 or 17, characterized in that the flexible blade (13) extends between the central zone (2) for mounting the bindings (3, 4) and the front contact point (11) . Ski according to any one of claims 16 or 17, characterized in that the flexible blade (13) extends between the central zone (2) for mounting the bindings (3, 4) and the rear contact point (12) . Ski according to either of Claims 16 and 17, characterized in that the flexion blade (13, 13a, 13b, 13c) extends both over the central area (2) for mounting the bindings and over the area located between said central area (2) and the front contact point (11). Ski according to either of Claims 16 and 17, characterized in that the flexion blade (13, 13a, 13b, 13c) extends both over the central area (2) for mounting the bindings and over the area located between said central area (2) and the rear contact point (12). Ski according to any one of claims 18 to 21, characterized in that the flexion blade (13, 13a, 13b, 13c) is fixed rigidly to the ski by its rear end (131), while its front end (130) is linked to the ski by the friction means (14). Ski according to any one of claims 18 to 21, characterized in that the flexion blade (13, 13a, 13b, 13c) is rigidly fixed to the ski by its front end (130), while its rear end (131) is linked to the ski by the friction means (14). Ski according to claim 20, characterized in that it comprises two flexion blades, a front flexion blade (13a) whose front end is fixed to the front of the ski and extending towards the rear, a blade rear flexion (13b) whose rear end is fixed to the rear of the ski to extend forward, the rear ends of the front blade (13a) and front of the rear blade (13b) overlapping in the central zone (2) and being connected together by an elastic connection (145), each of the blades being moreover connected to the ski in their middle part (132) by friction means (14).

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