CH675541A5 - - Google Patents

Description

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Description

The present invention relates to skis used in winter sports, and intended to slide on snow and ice.

Skis generally have a lower sliding face connecting to two lateral faces along two lower edges provided with metal edges, the lateral faces connecting to an upper face. The skis have a relatively small width compared to their length, thus defining a longitudinal direction, their front end being curved upward to form a spatula. The upper face of the ski has an intermediate zone, or binding zone, for fixing a shoe for the user.

In traditional skis, the thickness of the ski body varies according to the longitudinal position considered, and has a maximum in the mounting area of the binding, area in which the bending moments are generally the highest during use ski. The greater thickness in the center and smaller in the vicinity of the ends simultaneously ensures a uniform distribution of the load, as taught for example by patent FR-A-985,174.

Furthermore, the licensee has already described, in French applications n ° 8,607,849, 8,607,850, 8,607,851 and 8,607,852, external forms of skis in which the lateral faces or edges have variable inclinations, the faces lateral being intended to come into contact with snow to obtain particular effects in particular during the turns.

As regards the internal structure of the ski, current skis generally have a composite structure in which different materials are combined so that each of them intervenes in an optimal manner, taking into account the distribution of mechanical stresses. The structure comprises resistance elements or resistance blades, made of a material having a high resistance and a great stiffness, in order to resist the bending and torsion stresses appearing in the ski. The structure further comprises in particular filling elements.

The two main modern composite structures which have given rise to large-scale applications in skiing are the sandwich structure and the box structure.

In the case of a sandwich structure, described for example in documents FR-A-1,124,600 (fig. 1 and 2) and FR-A-2,069,824, the ski comprises a central core, made of cellular material which can be partially hollow, reinforced above and below respectively by an upper resistance blade and a lower resistance blade, the resistance blades having qualities of resistance and stiffness superior to those of the core itself.

It has been observed that the sandwich structures make it possible to produce the skis which have the best gliding in direct tracks, that is to say in displacement in the longitudinal direction of the ski. On the other hand, their lateral attachment qualities on slopes or in turns are not optimal, and for this reason they prefer box structure skis.

In the box structure, described for example in documents FR-A-985 174, FR-A-1 124 600 (fig. 3), the ski comprises an internal core of cellular material which may be partially hollow, the core being surrounded by the resistance elements arranged in strips and partitions constituting a box.

The box structure gives the ski superior elasticity and mechanical resistance in flexion, and great resistance to torsion along the longitudinal axis.

It is found that it follows that such skis with box structure have optimal qualities of lateral attachment on slopes or when cornering on snow. On the other hand they are less efficient than the skis with sandwich structure as regards the sliding qualities.

Like the external shape of the ski, the box has a variable thickness depending on the longitudinal zone considered of the ski, according to this the external shape of the ski. Despite this variable thickness, which results in giving the box a greater thickness and rigidity in the center of the ski and lower in the vicinity of the ends, it is found that the intrinsic properties of the box disadvantage the sliding of the ski, compared to a structure in sandwich.

This results in a need to specialize skis, depending on the type of use that one wants to make of it, and one can choose a ski with a sandwich structure to obtain high speed, for example in downhill competition, and choose a ski with a box structure to get a good grip on the ice, for example in slalom competition.

The object of the present invention is in particular to avoid the drawbacks of known ski structures, by proposing a new structure conferring on the ski simultaneously optimal sliding qualities such as those of skis with sandwich structure, and optimal gripping qualities such as those of box structure skis.

According to another object of the invention, in a ski with box structure, the invention aims to define new means conferring on the ski body variable resistance properties according to the longitudinal position considered, without appreciably altering the properties of variable resistance according to the longitudinal position considered, without appreciably altering the properties obtained by the box structure, but making it possible to significantly improve the glide.

Another object of the present invention is to obtain an advantageously continuous variation of the properties of mechanical resistance as a function of the longitudinal position considered of the ski body, without major modification of structure, thus achieving a homogeneity of structure and behavior, good distribution of reactions along the ski, giving the user an impression of comfort and regularity of the ski reactions.

Another object of the invention is to define means making it possible to combine, in the same ski, the sliding and fastening properties obtained

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by the new structure and the properties of reaction with snow obtained by the external forms of the ski with variable inclined edges.

The characteristics and advantages of the present invention will emerge from the following description of particular embodiments, made in relation to the attached figures, among which:

Fig. 1 shows a perspective view of a ski according to the invention;

fig. 2 shows a top view of the ski of FIG. 1;

fig. 3 shows a side view of the ski of FIG. 1;

fig. 4, 5, 6, 7 and 8 respectively represent cross sections of the ski of FIG. 2 along the vertical planes B-B, C-C, D-D, E-E and F-F;

fig. 9 shows a top view of another embodiment of the ski according to the invention, the ski having a variable asymmetry as a function of the longitudinal position considered;

fig. 10, 11 and 12 respectively represent cross-sectional views of the ski of FIG. 9 along the vertical planes C1-C1, D1-D1, E1-E1;

fig. 13 shows a top view of another embodiment of the ski according to the invention, having another form of asymmetry by lateral translation of the upper face of the ski relative to the lower face of the ski;

fig. 14 and 15 respectively represent cross-sectional views of the ski according to FIG. 13 according to plans C2-C2 and E2-E2;

fig. 16 illustrates an embodiment according to the invention in which the lateral faces of the box are convex;

fig. 17 shows an embodiment in which the lateral faces of the box are concave, and FIG. 18 shows an embodiment in which the upper face of the box is concave.

As shown in the figures, a ski according to the present invention generally comprises an upper face 1, a lower face 2 or sliding surface, a first lateral face 3, a second lateral face 4, a front end curved upwards in tip shape 5. The underside 2 of the ski is arched upwards between the front contact line 6 and the rear contact line 7. The ski body, or part of the ski comprised between the front contact line 6 and the rear contact line 7, has a maximum thickness in its central zone 8, and a thickness which gradually decreases when one approaches the front contact lines 6 and rear 7.

In the embodiment shown in FIGS. 1 to 8, the ski has a structure with a mechanical resistance box symmetrical with respect to the median longitudinal vertical axis l-l of the ski. Fig. 6 shows a cross section of the ski or the vicinity of its central area 8, section along the plane D-D. In this section, it can be seen that the ski is made up of three main parts: a core 10, of substantially rectangular section, a shell 20, and a lower element 30.

The core 10 can be made of different materials, such as wood or synthetic foam, or other cellular structures and for example aluminum honeycomb; the core can also be partially hollow, consisting for example of metal tubes x> u plastic.

The shell 20, in the embodiment shown, is a composite shell comprising an external appearance layer 21, for example made of thermoplastic material, and a reinforcing layer 22 made of a material with high mechanical resistance such as a laminate or an aluminum alloy. An inner filling layer 23 provides the connection between the core 10 and the reinforcing layer 22.

For example, the outer layer 21 is made of a thermoplastic material such as acrylonitrile butadiene styrene, commonly known as ABS, or a polyamide, or a polycarbonate.

The reinforcing layer 22 can be produced from one or more sheets of glass, carbon or other fabric, these layers advantageously being impregnated with thermoplastic resins such as polyetherimides, or thermosetting resins such as epoxides or polyurethanes . The glass fabric or the like is of the rather unidirectional type, and comprises for example 90% of fibers in the lengthwise direction of the ski, and 10% in the transverse direction. The reinforcing layer 22 can also be made of a metal alloy with a high elastic limit or made of metal glasses, or even a combination of these two materials.

The filling layer 23 can be made of thermoplastic material, either of the same nature as the outer layer, or of a different nature, for example of a nature such that the softening point is lower.

The lower element 30 comprises a sole 31 of polyethylene constituting the lower face 2 of the ski or sliding surface, lateral edges of steel 32 and 33, and a lower resistance blade 34 of a mechanically resistant material. For example, the lower resistance blade 34 may have a composite structure, comprising a lower layer 341 of glass fibers and an upper layer 342 of aluminum alloy or laminate. The lower resistance blade 34 is secured, along its lateral edges, to the corresponding lower lateral edges of the reinforcing layer 22 of the shell 20.

The reinforcing layer 22 of the shell 20 has, as shown in the figure, an inverted U-shaped structure, constituting an upper resistance strip 221, itself connecting to two lateral resistance walls 222 and 223 secured to their lower edges at the lateral edges of the lower resistance blade 34. In this way, the reinforcing layer 22 of the shell and the lower resistance blade 34 constitute a closed box structure, surrounding the core 10. As shown in FIGS. 4 to 8, the shape and dimensions in section of the box vary according to the area considered along the ski. So in the central area re5

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presented in fa fig. 6, the box has a trapezoidal section with lateral resistance walls 222 and 223 slightly inclined relative to the median longitudinal plane l-l of the ski. Thus, the lateral resistance walls 222 and 223 define, with the lower resistance blade 34, an internal angle A, or angle of inclination, the value of which is close to 90 °.

In fig. 7, in the rear intermediate zone E-E of the ski, the height of the box is lower, and the angle of inclination A is lower, for example of the order of 70 ° as shown in the figure.

In the vicinity of the rear contact line, in zone F-F, fig. 8 shows that the box is then very flattened, its thickness being small, and, simultaneously, the angle of inclination A is small, for example 10 to 20 ° as shown in FIG. 8. The core 10 has a very small thickness.

Likewise, in the front intermediate zone of the ski shown in FIG. 5, or zone according to section C-C, the box has a reduced height and the angle of inclination A is small, for example around 45 ° as shown in the figure.

And in the vicinity of the front contact line 6, the box is very flattened and consists of two upper and lower resistance blades attached to one another; we can then consider that the angle of inclination A is less than 10 °, or even zero.

The structure of fig. 6 is a traditional box structure, while the structure of FIG. 4 or fig. 8, although being box-shaped, has the behavior of a sandwich-type structure, in that the angle A is small. The transition from one to the other takes place gradually, by progressive reduction of the thickness of the ski and simultaneous reduction of the angle of inclination A, when one passes from the central zone of the ski represented on the fig. 8 to an end zone shown in FIG. 4 or in fig. 8.

Without departing from the scope of the present invention, it is possible to provide a symmetrical structure of the type of FIGS. 1 to 8 while choosing construction variants. For example, a ski structure according to the invention can be defined in which, in the central zone of the ski, the lateral resistance walls 222 and 223 are substantially vertical, the angle of inclination A then being close to 90 °.

In another embodiment, it is possible to provide in the central zone an angle of inclination A of less than 90 °, for example 80 ° as shown in FIG. 6.

It is also possible to provide a homogeneous lower resistance blade 34, comprising a single layer of resistant material, or more than two layers.

The presence of the outer layer 21 is not essential to obtain the particular effects according to the invention, and a ski structure can be defined in which the outer layer 21 and the reinforcing layer 22 are one and the same layer. reinforcement.

These same variants can be applied in the embodiments which will be described below, in which the ski has an asymmetrical structure in cross section.

In the embodiment shown in FIGS. 9 to 12, the ski according to the invention has a variable asymmetry along the ski body as a function of the longitudinal position considered. Thus, in the front area of the ski, as shown in section C1-C1 in FIG. 10, the first lateral resistance wall 222 of the box has a tilt angle A1 smaller than the tilt angle A2 of the second lateral resistance wall 223; on the other hand, in the rear zone, represented in section in FIG. 12, the angle A1 is greater than the angle A2, and, in the central zone of the ski shown in section in FIG. 11, the angles A1 and A2 are equal.

In the embodiment shown in FIGS. 13 to 15, the ski is also asymmetrical, and the asymmetry is always in the same direction with respect to the median longitudinal plane I-1 of the ski. In this case, the angle of inclination A1 is greater than the angle of inclination A2 over the entire length of the ski.

Of course, in these two previous embodiments, the angles A1 and A2 vary as a function of the position considered along the ski, and their variation is of the same type as that of the embodiment of FIGS. 1 to 8: in the central area, the angle admits a maximum value, and decreases when you get closer to the ends of the ski.

There is shown in Figs. 16 to 18 some other variants of the longitudinal profile of the box according to the invention. Thus, in fig. 16, the lateral resistance walls 222 and 223 are convex, for example in the form of a cylinder portion. In fig. 17, the lateral resistance walls 222 and 223 are concave. In fig. 18, the upper resistance blade 221 is concave, while in the previous embodiments it was substantially planar and simply arched longitudinally upwards.

In the embodiments which have been shown, the lateral resistance walls 222 and 223 are substantially parallel to the external lateral faces 4 and 3 respectively of the ski, and, in certain embodiments, they constitute by themselves said external lateral faces . The lateral resistance walls, inclined and with variable inclination, then combine the effects of modification of the behavior of the box and of the ski for gliding and hooking, and of behavior of the ski linked to the shape of the lateral faces of the ski.

The ski according to the present invention can be manufactured by traditional means, for example by a process described in document FR-A-985,174.

However, the ski according to the invention can also be manufactured according to a process described in French patent application No. 8,703,119 filed the same day by the holder.

The present invention is not limited to the embodiments which have been explicitly described, but it includes the various variants and generalizations thereof contained in the field of claims below.

Claims (11)

Claims 1. Skiing for evolution on snow or ice, including 5 10 15 20 25 30 35 40 45 50 55 60 65 4 7 CH 675 541 A5 body comprises, substantially over its entire length, a core (10) surrounded by a mechanical resistance box, the box comprising an upper resistance blade (221) secured to two lateral resistance walls (222, 223) themselves secured to '' a lower resistance blade (34), the lateral resistance walls (222, 223) forming with the lower resistance blade (34) an angle of inclination (A), characterized in that at least one of the walls of lateral resistance has a variable tilt angle A along the ski body as a function of the longitudinal position considered, giving the ski body mechanical resistance properties which are variable as a function of the longitudinal position considered. 2. Ski according to claim 1, characterized in that the angle of inclination (A) in the central zone of the ski is greater than the angle of inclination (A) in the vicinity of at least one of the ends of the ski contact area. 3. Ski according to any one of claims 1 or 2, characterized in that the angle of inclination (A) in the central zone of the ski is greater than the angle of inclination (A) in the vicinity of the line front contact (6) of the ski. 4. Ski according to any one of claims 1 to 3, characterized in that the angle of inclination (A) in the central zone of the ski is greater than the angle of inclination (A) in the vicinity of the line rear contact (7) of the ski. 5. Ski according to any one of claims 1 to 4, characterized in that the lateral resistance walls (222, 223) are symmetrical to each other with respect to a median longitudinal vertical plane (ll) of the ski . 6. Ski according to any one of claims 1 to 4, characterized in that the lateral resistance walls (222,223) are asymmetrical. 7. Ski according to any one of claims 1 to 6, characterized in that the angle of inclination (A) is at most equal to 90 ° over the entire length of the ski body. 8. Ski according to any one of claims 1 to 7, characterized in that the angle of inclination (A) is substantially equal to 90 ° in the central area of the ski. 9. Ski according to any one of claims 1 to 8, characterized in that, in the vicinity of at least one of the two contact lines (6, 7), the angle of inclination (A) is less than 10 °. 10. Ski according to any one of claims 1 to 9, characterized in that the angle of inclination (A) varies continuously along the body of the ski. 11. Ski according to any one of claims 1 to 10, characterized in that the lateral resistance walls (222, 223) are substantially parallel to the corresponding outer lateral faces (4,3) of the ski. 5 10 15 20 25 30 35 40 45 50 55 60 65 5