EP0580522B1 - Ski with improved profile - Google Patents

Abstract

This ski, more particularly intended for alpine skiing, includes a gliding sole (17) and metal edges (18), the lateral sharp edges of which are connected to the upper face (3) by lateral sidewalls (2). On the upper face (3) and in front of and/or behind the central zone of the runner (skate) (8) there extends at least one recess (9, 10), the depth of which decreases from the said zone of the runner in the direction of the two ends (4, 5). <IMAGE>

Description

The invention relates to a ski with an improved profile, in particular intended for the practice of winter sports, and more particularly for the practice of alpine skiing.

In known manner, the skis consist of a sliding sole, intended to be in direct contact with snow or ice, and the lateral edges of which are provided with metal edges, themselves connected to the upper face of the ski. by side portions called edges. These edges can be vertical or tilted.

Traditionally, the ski is thicker at the level of the skate than at the ends where the ski gradually thins. This greater thickness is intended on the one hand, to allow the mounting of the screws of the bindings which hold the shoes of the skier, and on the other hand and above all, to confer on this central zone an increased rigidity, in order to allow a distribution sufficiently spread of the load induced by the mass of the skier.

In addition, in order to give the ski qualities of liveliness and nervousness, it is important that its two ends are relatively flexible and thin.

We have for example proposed in document FR-A-2 664 172 (SALOMON) a ski in which on the one hand, the skate area has a central rib intended, with suitable shoes, to allow the approximation between the foot of the user and the edges, in order to improve the efficiency of the edge grips, and on the other hand, the anterior and posterior zones of the ski with respect to the central pad have been lowered at the level of the middle part and raised on the edges in the form of lateral ribs. In this way, it is possible to obtain flexibility of the ends, while retaining masses of inertia improving the dynamic behavior of the ski.

However, if it is true that in this way, the ski obtained has sufficient inertia in its upstream and downstream zones with respect to the skate, while thereby giving the ski greater flexibility and, consequently, promoting the bending of the ski and therefore the rounding of the turn, on the other hand, such a configuration reveals an alteration in the rigidity of the ski, in particular in torsion, which results from the bringing together of the reinforcing elements of the neutral fiber of the ski in the anterior and posterior zones. However, this lower rigidity is reflected on the one hand, by a relative weakness of the ski, which can even lead to risks of breakage, and on the other hand by the genesis of vibrations, significantly altering the behavior of the ski on snow, in particular making it more difficult to keep the ski on the desired path. In addition, the ski according to this configuration requires either the use of specific boots, comprising a large central groove making it possible to house the central rib of the ski, or the use of specific fixing plates compatible with the presence of the central rib of the ski. .

Lightening skis is now a major concern for producers, as too heavy a ski can cause discomfort for the user. Indeed, such a ski is difficult to place in the trajectory, it is not very handy and gives the skier the impression of remaining stuck in the snow. On the other hand, extremities that are too light can generate in the course of use, other unpleasant sensations, in particular giving the impression of badly locating the spatulas by lack of directive effect, which can materialize by inaccuracies in the trajectory. Such a ski has for example been described in document JP-52-6239.

The object of the invention is to provide a ski which overcomes these various drawbacks by proposing a lighter ski, while retaining the inertia of the anterior and posterior zones necessary for increasing the characteristics of liveliness and reactivity of the ski .

The practice of special slalom, and more generally that of free skiing on the track in short turns, requires specific qualities. Indeed, the skis are then energetically stressed, in particular in the form of large edge grips, implying good resistance in lateral bending. In other words, under the effect of a load directly applied to their edges, they must flex as little as possible laterally and / or twist. Indeed, untimely lateral deformations would inevitably generate inaccuracies in the conduct of turns as well as "drops" of edges, possibly possibly causing the skier to fall.

Furthermore, it has been shown that it is possible to modulate the performance of a ski by modifying the pressure distribution of the ski on the snow.

The ski according to the invention comprises a gliding sole provided with metal edges, the lateral edges of which are connected by vertical or inclined edges with respect to the perpendicular of the sole to the conventionally continuous upper face seen in profile, and on the face at least one of which and in front of and / or behind the central zone of the skid, extends at least one recess, the depth of which decreases from said zone of the skid to the vicinity of the front and / or rear contact line of the ends of the ski. The thickness of the ribs defined by said recess decreases from the area of the pad to the vicinity of the contact line before and / or rear of the ends, and the width of the recesses widens from the pad in the direction of said ends.

This ski comprises, in known manner, reinforcing elements, situated on either side and as far as possible from its neutral fiber, and in particular in internal contact with the decorative element on one side, and the sole of the other side. These reinforcing elements are typically made from a metal alloy, such as an alloy based on aluminum and zinc (ZICRAL - registered trademark) or in a textile sheet, for example green, carbon fibers, or polyaramide (KEVLAR - registered trademark), possibly pre-impregnated with a thermosetting resin. The upper reinforcing element may advantageously have at the ends, the shape of an inverted omega (Ω), the loop of which corresponds to the bottom of the recess characteristic of the invention, and the lateral wings of which make it possible to increase significantly the lateral flexural strength of the ski.

In other words, the invention consists in not modifying the traditional skate area, that is to say in preserving the upper surface of the ski without breaking or discontinuity, in contrast to skis having a projecting platform, but especially to generate ribs on either side of the skate area and on the two lateral edges of the upper face of the ski, which then has the shape of an inverted Ω, capable of giving it rigidity in lateral bending, and in torsion, greater than that of skis known to date, and therefore promote the stability of this ski.

In a first embodiment, the recesses are symmetrical with respect to a vertical plane passing through the longitudinal longitudinal line of the ski. In other embodiments, these recesses have a certain asymmetry, and in particular a variation in depth, the ribs of the same flare being able to be of different dimensions, the bottom of the flare not necessarily being parallel to the sole. .

In a particular case, the upper face provided with these recesses is attached and fixed to the entire ski by gluing. In another embodiment, the ski provided with these two recesses is obtained directly from molding.

The manner in which the invention can be implemented and the advantages which ensue therefrom will emerge more clearly from the example of embodiment which follows, given by way of indication and without limitation in support of the appended figures.

Figure 1 is a schematic perspective representation of a ski according to the invention.

Figure 2 is a top plan view of this ski.

Figure 3 is a schematic view in longitudinal section along the median axis of a first embodiment of the ski.

Figure 4 is a view similar to that of Figure 3 of a second embodiment of this ski.

Figures 5 to 11 are schematic representations of cross sections of the ski according to the invention, made along the lines shown in Figures 2, 3 and 4, and referenced in Roman numerals whose number corresponds to the figure concerned.

Figures 12 and 13 are also cross sections along the line VI - VI of Figure 2, but of a particular embodiment according to the invention.

Figures 14 and 15 are partial longitudinal sections showing alternative embodiments of the front part of a ski according to the invention.

FIG. 16 is a graph representative of the stiffness curve of a traditional ski and of a ski according to the invention.

Referring to FIG. 1, in which a ski according to the invention is shown diagrammatically and bears the general reference (1), this basically consists of a central zone or pad (8) of thickness greater than those of the two ends, and typically about 20 (twenty) millimeters, and extending over a distance close to 600 (six hundred) millimeters. These two ends are respectively constituted by the heel (4) and the spatula (5), of upwardly curved shape. Traditionally, the tip and the heel are lifted up slightly from a line so-called front (6) and rear (7) contact respectively. The thickness of the ski at these two ends is reduced relative to the skate, and is close to 5 (five) millimeters.

In addition, this ski comprises a gliding sole (17), connected to the upper face of the ski (3) by lateral edges (2), possibly inclined relative to the perpendicular of the sole. It goes without saying that the invention can also be applied to skis with rectangular cross section, that is to say with vertical side edges.

According to a fundamental characteristic of the invention, the upper face (3) has two recesses, respectively an anterior recess (9) and a posterior recess (10), located on either side of the area of the pad (8) and extending to the surroundings respectively of the planes integrating the front (6) and rear (7) contact lines.

As can be seen in FIG. 1, these recesses (9) and (10) widen from the area of the skid to the aforementioned contact planes. In addition, they are more hollow in the vicinity (15,16) of the shoe (8) than towards the ends, so that their depth decreases from the area of the shoe to the said contact planes, and generates on the lateral edges of the face. upper (3), respectively anterior (11) and (12) and posterior (13) and (14) ribs. These ribs of variable thickness (in transverse direction with respect to the ski) are more visible on the transverse sections 5 to 11, described in more detail below.

We can thus observe in Figure 5 corresponding to the cross section along the line VV of Figure 2, and typically made at the front contact plane (6), a traditional section of a ski, located at the tip , the edges (18) and the base (17) of the sole of which have also been shown diagrammatically.

On the next section (Figure 6) made around the middle of the anterior recess (9), we can observe the two lateral ribs (11) and (12), each of said ribs being limited on one side by the edge ( 2) of the ski, and on the other side by a chamfer (21,22), as well as the bottom (19) of said recess (9). At this level, the base of the recess is about to join the normal thickness of the ski, in particular at the level of the front contact line. In fact, the depth of the recess at this level is reduced.

This depth increases in Figure 7, at which the corresponding section is close to the start (16) of the recess (9). In fact, the depth is significantly greater and the two ribs (11) and (12) are also of greater thickness.

FIG. 8 corresponds to a section made at the level of the pad area (8), an area of maximum thickness intended to receive the fasteners. In the absence of a recess at this level, the upper face (3) is flat and parallel to the sole (17).

Figures 9 and 10 correspond respectively to Figures 7 and 6 for the posterior recess.

And finally, FIG. 11 corresponds to the rear contact zone, that is to say at the start of the heel, and therefore of reduced thickness.

In Figures 5 to 11, the recesses have been shown symmetrically. Thus, the ribs (11,12) on the one hand, and (13,14) on the other hand are of equal thickness and equal height relative to the bottom (19) of the corresponding recesses. In addition, the plane materialized by the bottom (19) is parallel to the sole (17), and the slopes (21) and (22) joining the top of the ribs to the bottom (19) are also symmetrical with respect to the midline. longitudinal of the ski (1).

In other embodiments of the invention, it is also possible to envisage asymmetrical recesses, as shown in FIGS. 12 and 13, in which, on the one hand, the plane materialized by the bottom (19) of the recesses ( 9) and (10) is not parallel to the sole (17), but also in which the ribs themselves do not have the same thickness and / or the same shape, as shown in particular in FIG. 13.

In FIG. 14, the plane of the bottom (19) is parallel to the sole, while in FIG. 15, this bottom is not parallel to the sole (17). This non - parallelism occurs longitudinally in Figure 15, while it is transverse in Figures 12 and 13.

In this way, skis are obtained which are themselves asymmetrical, in particular from the point of view of the distribution of the masses, but also reinforcing elements, making it possible to differentiate between a right ski and a left ski. Each of the two skis constituting a pair therefore has inertia and resistance to the various specific flexural stresses, inducing a different behavior, in particular when cornering, thereby optimizing the initiation of turns and / or the grips of edges.

FIGS. 3 and 4 show a ski according to the invention in longitudinal section.

Thus, in a first embodiment represented in FIG. 3, the ski according to the invention is obtained directly from the molding, the mold having male parts corresponding to the recesses (9) and (10) of the ski, the different elements entering in the constitution of the ski, in particular the sole, the lower and upper reinforcing elements and the decoration being placed in the mold, and the central core is injected, typically made of polyurethane foam, the expansion causes the elements to be pressed against the internal walls of the mold and thereby imparting in skiing the final shape sought, and in particular the two recesses (9) and (10). Either, the ski is obtained in two stages, a first phase of realization of the shell by stamping of metallic reinforcements, or by thermoforming or pre-molding of a thermoplastic or thermosetting shell or of fibrous reinforcements, and a second phase of injection of the central nucleus.

In another embodiment shown in FIG. 4, an upper part (20) presenting the two recesses (9) and (10) is reported on a ski (1) produced in the traditional manner, for example these being obtained by machining, and revealing the ribs (11 - 14). The part (20) is fixed to the ski (1), in particular by bonding, either directly or even, by means of an elastic or visco-elastic film, with the aim of increasing the damping characteristics thereof. .

FIG. 9 materializes the upper reinforcement element (23) of the ski according to the invention. As already said, this reinforcing element can be constituted by a metallic alloy, or by a textile sheet pre-impregnated with a thermosetting resin. It is positioned in internal contact with the decor element (24), and is therefore relatively distant from the neutral fiber of the ski. As can be seen in FIG. 9, this reinforcing element has an inverted Ω shape, the wings of which are separated, and the loop of which adopts the shape of the bottom (19) of the flare (10). The wings follow the internal shape of the ribs (13,14). In this way, it is understood that at the areas adjacent to the skate area, the ribs being thicker, the wings of the reinforcing element are longer, thus giving this area increased resistance to lateral bending forces. , notwithstanding the loss of thickness due to the recess.

The skis thus obtained exhibit very good resistance in lateral bending, in particular due to the lateral wings of the upper reinforcement element in the form of Ω. The increased depth of the recesses at proximity to the skate area also makes it possible to correct the stiffness curve of the ski, while reducing the mass of the ski and maintaining at the ends a sufficient mass to release a correct inertia and a sufficient resistance to bending forces to allow to obtain a ski of good reactivity and nervousness, and also of precision.

FIG. 16 shows the stiffness curve of a traditional ski, in solid lines, and of the ski according to the invention, in which the reduction in stiffness clearly appears in the adjacent areas of the skate area, while retaining the required stiffness at the ends.

Claims (8)

1. A ski, in particular alpine ski, comprising a running sole (17) and metal edges (18), whose lateral ridges are connected by lateral sides (2) to the upper face (3) which is conventionally continuous when laterally viewed, said upper face (3) presenting in front of and/or behind the central zone of the support face (8) at least one recess (9, 10), whose depth decreases from said zone of the support face (8) to the vicinity of the front (6) and/or rear (7) contact line of the ends (4, 5) of the ski, characterized in that the thickness of the ribs (11 - 14) defined by said recess (9, 10) decreases from the support face (8) to the vicinity of the front (6) and/or rear (7) contact line of the ends (4, 5) of the ski, and in that the width of the recess (9, 10) widens from the zone of the support face (8) in the direction of the ends (4, 5).
2. The ski as claimed in claim 1, comprising reinforcement elements, situated on either side of its neutral axis, produced on the basis of a metal alloy or a textile cloth preimpregnated with a heat-setting resin, wherein the upper reinforcement element (23) has the shape of an inverted omega (Ω), in which the loop corresponds to the base of the recess (19), and whose lateral wings adopt the inner shape of the ribs (11-14) defined by said recess.
3. The ski as claimed in one of claims 1 and 2, wherein each of the recesses (9, 10) is symmetrical with respect to a vertical plane passing through the longitudinal midline of the ski.
4. The ski as claimed in one of claims 1 and 2, wherein the recesses (9, 10) have a certain degree of asymmetry with respect to a vertical plane passing through the longitudinal and/or transverse midline of the ski.
5. The ski as claimed in claim 4, wherein the base (19) of said recesses (9, 10) is not parallel to the sole (17).
6. The ski as claimed in one of claims 4 and 5, wherein the ribs (11, 12) and (13, 14) of a same recess (9, 10) are of different shape, and in particular thickness and/or height.
7. The ski as claimed in one of claims 1 to 6, wherein the upper face (3) provided with its recesses (9, 10) is attached to the ski by gluing.
8. The ski as claimed in one of claims 1 to 7, wherein said ski is formed directly by molding.

Images