EP0283331B1 - Ski having a longitudinal upper rib - Google Patents

Abstract

PCT No. PCT/FR88/00061 Sec. 371 Date Oct. 5, 1988 Sec. 102(e) Date Oct. 5, 1988 PCT Filed Feb. 4, 1988 PCT Pub. No. WO88/05676 PCT Pub. Date Aug. 11, 1988.The ski comprises at its top part a longitudinal rib usable particularly for the lateral guiding of a shoe. In order to improve the technical qualities of the ski without substantially increasing its weight, the cross-section of the rib is comprised at least in the front part of the central area (A) where the shoe sole is bearing, of the superposition of at least two elementary sections (2,3) having each the shape of a quadrilateral and interconnected by a common side forming the lower side of the upper elementary section and the upper side of the lower elementary section of which the lower side is horizontal, the lateral sides (7,8) of the lower elementary section (3) converging upwards and being more inclined with respect to a vertical and longitudinal plane than those (5,6) of the upper elementary section (2).

Description

The present invention relates to a ski comprising a longitudinal rib at its upper part.

Skis are already known, in particular cross-country skis, which have a longitudinal rib on their upper face. This longitudinal rib generally has a trapezoidal cross section, in other words it is delimited by a horizontal upper face and two inclined lateral faces, and this rib with trapezoidal cross section connects to the lower part of the ski which has a rectangular cross section, of low height, whose short sides constitute the edges of the ski. Due to the reduced height of these edges, such a ski slides more easily on snow. Furthermore, in the case of a cross-country ski, the upper longitudinal rib can be used in particular for the lateral guidance of the boot mounted on the cross-country ski, which is adapted for this purpose thanks to the provision, in its sole, a groove having in cross section a shape complementary to that of the rib of the ski. Such cross-country skiing is known in particular from patent FR-A-2565114.

The present invention relates to improvements made to such a ski with the aim of improving its technical qualities, without notably increasing its weight.

To this end, this ski comprising a central zone in which the sole of a shoe is supported and which is situated between two longitudinal front and rear zones which extend the central support zone respectively towards the front and towards the rear, and which are connected to flat anterior and posterior end portions of the ski, and an upper longitudinal rib extending over the most large part of the length of the ski, up to its flat end portions, is characterized in that the transverse section of the rib is formed, in the central zone, by the superposition of at least two elementary sections each having the form of '' a quadrilateral and connected by a common side constituting the lower side of the upper elementary section and the upper side of the lower elementary section whose lower side is horizontal, the lateral sides of the lower elementary section converging upwards and being more inclined, with respect to a vertical and longitudinal plane, than those of the upper elementary section, and in that in the anterior and posterior zones the transverse section of the rib has the shape of a single quadrilateral.

• La figure 1 est une vue en perspective d'un ski de fond à nervure longitudinale, avec des illustrations de la section transversale du ski en différents points de sa longueur.
• Les figures 2 à 20 sont des vues en coupe verticale et transversale, à plus grande échelle, de diverses formes d'exécution du ski suivant l'invention.
• La figure 21 est une vue en perspective d'une variante d'exécution du ski de fond.

Various embodiments of the present invention will be described below, by way of non-limiting examples, with reference to the appended drawing in which:

• Figure 1 is a perspective view of a cross-country ski with longitudinal rib, with illustrations of the cross section of the ski at different points of its length.
• Figures 2 to 20 are views in vertical and transverse section, on a larger scale, of various embodiments of the ski according to the invention.
• Figure 21 is a perspective view of an alternative embodiment of cross-country skiing.

In FIG. 1 is shown a cross-country ski 1 which has a cross section with an evolving profile in the longitudinal direction and which has, at its upper part, over most of its length, a longitudinal rib. The cross section of this rib, located above the edges of the ski, is made up, on certain parts of the length of the ski, by a single quadrilateral, in this case an isosceles trapezoid and, on another part of the length, by two superimposed quadrilaterals, in this case two isosceles trapezoids. More particularly, the cross-country ski 1 can be subdivided into three longitudinal zones where the longitudinal rib is formed, namely a central zone A which bears a cross-country ski chase (not shown) which is connected to the ski at its front end and whose the sole is provided with a longitudinal groove, and two front longitudinal zones B and rear C which extend the central support zone A respectively towards the front and towards the rear, and which are connected to anterior and posterior end portions flat, that is to say devoid of the longitudinal rib. In the anterior B and posterior C zones, the cross section of the rib of the cross-country ski 1 has the shape of a single isosceles trapezoid, while in the central longitudinal zone A its cross section consists of the superposition of two elementary sections, each has the shape of an isosceles trapezoid.

In FIG. 1 are represented various profiles of the cross section of the cross-country ski 1 along the length. At its extreme front cross-sectional part of the ski 1 1 has a flattened rectangular shape delimited laterally by the two vertical sides of the ski and 9.10 that is found all along the ski. The cross section of the rib, considered to be limited to the part situated above the lower rectangular part delimited by the edges 9, 10 and which is absent in the anterior extreme part, has, in the anterior longitudinal zone B, the shape of a single isosceles trapezoid, of height going backwards, as it is represented by the two profiles 1b of small height and 1c of greater height than the previous one. In the transverse connecting plane between the front and central zones B A cross section of the rib 1 passes to the unique shape of an isosceles trapezium with the two superimposed isosceles trapezoids, as shown by profiles 1d and 1 e. Then the cross section of the rib again takes the form of a single isosceles trapezoid in the posterior section C, as illustrated by the profiles 1f, 1g, up to the extreme posterior part of the ski where the rib is absent and the cross section of the ski has a flattened rectangular shape similar to that of the anterior end portion.

In the central support zone A, the length of which is in fact substantially equal to or slightly greater than that of the boot, the cross section of the rib of the cross-country ski 1 comprises an upper elementary section 2, defining a longitudinal guide rib proper, and a lower elementary section or base 3, these two elementary sections each having, in this case, the shape of an isosceles trapezoid. The upper guide rib 2 has a horizontal upper face or edge 4 which is extended downwards by two inclined lateral faces 5,6. The three faces 4,5,6 define the upper rib 2 which contributes to the lateral guidance and to the centering of the boot on the ski, as a result of the engagement of this guide rib 2 in the longitudinal groove of the sole of the boot, during the practice of cross-country skiing.

Preferably the inclination of the lateral faces 5, 6 of the upper guide rib 2, with respect to the vertical and longitudinal plane of symmetry P of the ski, varies from the front to the rear of the central support zone A. At the front of this central support zone A, that is to say where the anterior end of the boot is fixed, the angle a formed by the inclined lateral faces 5, 6 with the vertical plane P varies from 0 to 10 degrees and is preferably close to 5 degrees, while in the rear part of the central support zone A, where the heel of the shoe applies, this angle is more important and it can vary from 20 to 40 degrees.

The lower trapezoidal elementary section or base 3 comprises two inclined lateral faces 7,8 extending downwards the inclined lateral faces 5,6 and symmetrical with respect to the vertical plane P. The upper guide rib 2 and the lower base 3, all the two in the shape of an isosceles trapezoid, therefore have a common base, in the horizontal junction plane P1 between the inclined lateral faces 5,6 on the one hand and 7,8 on the other hand, which constitutes the large base of the rib trapezoidal upper 2 and the small base of the lower base 3.

The inclined lateral faces 7,8 of the base 3 are more inclined, with respect to the vertical and longitudinal plane P, than the upper inclined faces 5,6, the angle of inclination b of these faces 7,8 with respect to the plane P can vary from 30 to 60 degrees. The two lower inclined lateral faces 7,8 of the base 3 are connected to the vertical edges 9,10, of low height, of the ski.

Figures 2 to 20 illustrate, by way of non-limiting examples, various embodiments of the cross-country ski according to the invention. In these various embodiments cross-country skiing is achieved by assembling, by gluing, several profiles preferably made of a composite material of the glass-epoxy resin type.

In the embodiment shown in FIGS. 2 to 4, the cross-country ski is obtained by the assembly of two profiles, namely an external profile 11 or "shell", whose evolving cross section defines the profile of the ski over its whole length, as has been explained with reference to FIG. 1, and an internal profile 12 or "core" which retains the same shape of cross section over the entire length of the ski but whose height is variable. The ski also comprises a lower horizontal reinforcement element 13 which is glued under the core 12 and under this reinforcement element 13 is in turn glued the sole 14 of the ski itself. Figures 2 to 4 are shown various profiles of the shell 11 corresponding to that of the various cross sections of the ski. In FIG. 2 which represents a cross section of the ski in the central support zone A. The external shell 11 consequently has a cross section constituted by the two superimposed isosceles trapezoids and it comprises the upper horizontal face or edge 4, the faces upper 5.6 slightly inclined with respect to the vertical and longitudinal plane of symmetry P, and the lower lateral faces 7.8, more inclined with respect to the vertical plane P and which extend downwards by the vertical edges 9.10 of the ski . The inner core 12 has a cross section in the shape of an omega and it includes an upper horizontal wall 15, located under the edge 4 and glued to it, two side walls 16, 17, vertical or slightly inclined by with respect to the vertical and longitudinal plane P, by forming a rectangle or a central isosceles trapezoid, and two horizontal lower wings 18, extending outwards respectively from the lower ends of the vertical faces 16,17 and under which is glued the 'reinforcing element 13. These horizontal wings 18,19 may end with flanges 20,21 folded square upwards, parallel to the edges 9,10 and glued inside thereof.

Preferably the distance between the lateral and vertical faces 16,17, at their lower ends where they are connected to the wings 18,19, is equal to one third of the width d of the ski, each of the wings 18.19 therefore also having a width equal to one third of the width of the ski d / 3. The advantage of such a distribution is that it makes it possible to obtain effective support for the upper guide rib, formed by the faces 4,5,6, to reinforce the "internal element or core 12" when it is pushed in. to reinforce the ski edges and to fulfill the shearing functions of a ski core while providing a hollow and light structure, having an excellent resistance / weight ratio. Furthermore, the fact that the core 12 supports the ridge 4 for guiding the shoe and follows its shape, this core 12 transmits directly, by its lower part formed by the horizontal wings 18, 19, the forces exerted by the shoe on all parts of the ski in contact with snow, i.e. edges or edges 9.10.

FIG. 3 represents the shape of the cross section of the ski in the anterior A or posterior zone B. In this case the outer shell 11 has a cross section reduced to a single isosceles trapezium while the core 12, still in the form of an omega , has a reduced height.

FIG. 4 represents the cross section of the ski in one of its anterior or posterior end portions. In this case the outer shell 11 has a flat and horizontal shape and it covers the core 12, still in the form of an omega but of very reduced height.

Figures 5 to 7 illustrate various variants of the inner core of the ski.

In the embodiment of the invention shown in Figure 5 the inner core 22 has an I-shaped cross section whose upper horizontal wings 22a and lower 22b, connected by a vertical core 22c, are respectively glued in support under the edge 4 and on the central part of the reinforcing element 13.

In the alternative embodiment of the invention shown in Figure 6 the cross section of the central core 23 has the shape of an inverted Y, and this core comprises an upper vertical core 23a extending to the middle a horizontal wing 23b glued under the edge 4, two inclined lower branches 23c, 23d coming from the vertical core 23a, extending downwards and outwards and which are connected to respective horizontal wings 23e, 23f extending outwards and glued to the reinforcing element 13.

In the alternative embodiment of the invention shown in Figure 7 the cross section of the inner core is in the form of an omega and this core consists of two halves substantially symmetrical with respect to the plane P, each having substantially the shape of a Z. The upper horizontal wings 24a, 24b, extending towards the plane P, of these two Z-shaped halves are superimposed and glued to each other, under the edge 4, while the horizontal wings lower 24c and 24d, extending outwards, are glued to the reinforcing element 13. Vertical walls 24e, 24f extend respectively between the horizontal wings 24a, 24c on the one hand and 24b, 24d d ' somewhere else.

FIG. 8 illustrates an alternative embodiment in which the reinforcing element 13 has, in its central part, a longitudinal rib 13a projecting inwards, this rib 13a extending between the lower parts of the two lateral faces and vertical 16,17 of the core 12 in the shape of an omega.

FIG. 9 illustrates an embodiment in which each of the edges 9, 10 is extended inward by a rim with the respective square 9a, 10a held between the corresponding wing 18, 19 of the core 12 in the form of omega and the reinforcing element 13.

In the variant embodiment of the invention shown in FIG. 10, the reinforcing element 13 is extended, at its ends, by a flange 13b extending at right angles upwards and which is kept glued between the flanges 20.21 of the wings 18.19 of the core 12 in the shape of an omega and the edges 9.10.

FIG. 11 represents an alternative embodiment of a cross-country ski in which the edges 9, 10 practically no longer exist as such. In other words, in this alternative embodiment the lower inclined lateral faces 7,8 are connected directly to the ends of the wings 18,19 of the core 12 and to the ends of the lower reinforcement element 13, the assembly being carried out as before by gluing.

In the variant embodiment of the invention shown in FIG. 12, the lower horizontal wings 18, 19 of the omega-shaped core 12 end in flanges 22, 23 having in cross section the shape of an inverted U or open down. These U-shaped flanges 22,23 respectively cover the upwardly extending square edges 13b of the reinforcing element 13 and they are glued to both these edges 13b and to the edges 9,10 ski.

Although in the preceding description it has been indicated that the cross section of the ski rib, with an evolving profile, was constituted by a single isosceles trapezoid or two superimposed isosceles trapezoids, it is possible to produce the ski according to the invention with different quadrilateral profiles. Figures 13 to 17 illustrate, without limitation, some profiles which can be adopted for the cross section of the ski, in the central area where the two superimposed quadrilaterals are located.

FIG. 13 illustrates a cross section in which the upper elementary section 2 has a rectangular shape and is connected to the small upper base of a lower elementary section 3 in the form of an isosceles trapezoid, the assembly then being symmetrical with respect to the vertical plane and longitudinal P.

In the variant embodiment of the invention shown in FIG. 14, the upper elementary section 2 has the shape of a rectangular trapezoid also connected to a lower elementary section 3 in the form of an isosceles trapezium.

In the variant embodiment of the invention shown in FIG. 15, the upper elementary section 2 has the shape of any trapezium and it is connected to a lower elementary section 3 in the form of an isosceles trapezium.

Figures 16,17,18, illustrate embodiments in which the elementary section 3 smaller than the shape of any trapezoid, the upper elementary section 2 having the shape of a rectangle or a square (Figure 16 ), any trapezoid (Figure 17) or an isosceles trapezoid (Figure 18).

Figures 19 and 20 illustrate embodiments of the invention in which the two upper elementary sections 2 and lower 3 are constituted by any quadrilaterals. In this case the two quadrilaterals constituting the upper 2 and lower 3 elementary sections are connected along a common side, indicated in phantom, and which is contained in a junction plane P1 inclined relative to the horizontal. Here again the lateral sides 5,6, converging upwards, of the quadrilaterals constituting the upper elementary section 2 are less inclined, with respect to the vertical and longitudinal plane P, than the lateral sides 7,8, convrerging upwards, of the quadrilateral constituting the lower elementary section 3. Furthermore, in the embodiment of the invention shown in Figure 19, the upper side 4 of the upper elementary section 2 is horizontal, while in the embodiment of the invention shown in Figure 20, this side is inclined relative to the horizontal.

FIG. 21 represents an alternative embodiment of the ski in which the central support zone A comprises a front part in which the cross section of the ski consists of two superimposed quadrilaterals, in this case two isosceles trapezoids, while its posterior part consists of a single quadrilateral, in this case an isosceles trapezium. In this case the ski boot is guided at the front by the upper longitudinal rib engaging in a relatively narrow groove, formed in the front part of the shoe, while the heel of this shoe comes to bear on the rear part of the central zone A, with a cross section in the shape of a single isosceles trapezoid. The lower surface of the heel can then be flat, in which case the heel rests on the upper horizontal edge 4 of the rib, or else it can have a longitudinal notch so that this notch comes to cover the rib.

In all of the embodiments of the invention which have been described above, the interior of the ski can be left empty or it can be filled with an appropriate filling material. The upper longitudinal rib 2 of the ski has a width and / or height which is constant, as shown in the drawing, or variable along its length. It can be used not only for lateral guidance and centering of the shoe but also for mounting the binding holding the front end of the shoe.

Although it has been discussed in the foregoing description of the application of the invention to cross-country skiing, it goes without saying that the particular structure of the ski could be used for other types of ski, in particular for alpine skiing or ski touring.

Claims (25)

1. Ski comprising a central area (A) where the sole of a shoe bears and which is located between two front (B) and rear (C) longitudinal areas which extend the central bearing area (A) respectively forwardly and rearwardly, and which are joined to front and rear plane end parts of the ski, and an upper longitudinal rib extending over the greater part of the length of the ski, up to its plane end parts, characterized in that the transverse section of the rib is constituted, in the central area (A), by the superposition of at least two elementary sections (2, 3) each having the form of a quadrilateral and interconnected by a common side constituting the lower side of the upper elementary section and the upper side of the lower elementary section of which the lower side is horizontal, the lateral sides (7, 8) of the lower elementary section (3) converging upwardly and being more inclined, with respect to a vertical and longitudinal plane (P), than those (5, 6) of the upper elementary section (2), and in that, in the front (B) and rear (C) areas, the transverse section of the rib has the form of a single quadrilateral.
2. Ski according to Claim 1, characterized in that the lateral sides (5, 6) of the upper elementary section (2) converge upwardly.
3. Ski according to Claim 1, characterized in that the lateral sides (5, 6) of the upper elementary section (2) are vertical.
4. Ski according to any one of the preceding Claims, characterized in that the bearing area (A) of the sole of the shoe has a length which is equal to or greater (2) than that of the shoe.
5. Ski according to any one of the preceding Claims, characterized in that it is obtained by assembling two profiles, namely an outer profile (11) or "shell", of which the evolutive transverse section defines the profile of the ski over the whole of its length, and an inner profile (12) or "core" which conserves the same shape of transverse section over the whole length of the ski but whose height is variable.
6. Ski according to Claim 5, characterized in that it comprises a lower horizontal reinforcing element (13) which is glued beneath the core (12) and beneath this reinforcing element (13), the sole (14) proper of the ski is, in turn, glued.
7. Ski according to either one of Claims 5 and 6, characterized in that the core (12, 22, 23, 24) comprises an upper horizontal wall (15, 22a, 23b, 24a) glued beneath the horizontal upper face or edge (4) of the outer shell (11), at least one horizontal wall (18, 19; 22b, 23e, 23f; 24c, 24b) glued to the horizontal lower reinforcing element (13) and at least one vertical wall (16, 17; 22c; 23a; 24e, 24f) extending between the upper and lower horizontal walls.
8. Ski according to Claim 7, characterized in that the inner core (12) has a transverse section in omega form and it comprises an upper horizontal wall (15), located beneath the edge (4) and glued thereto, two lateral walls (16, 17), vertical or slightly inclined with respect to the vertical and longitudinal plane (P), forming a rectangle or a central isosceles trapezium, and two horizontal lower flanges (18) extending outwardly respectively from the lower ends of the vertical faces (16, 17) and beneath which the reinforcing element (13) is glued.
9. Ski according to Claim 7, characterized in that the inner core (22) has a transverse section in I form, whose upper and lower horizontal flanges (22a) and (22b), connected by a vertical web (22c), are respectively glued in abutment beneath the edge (4) and on the central part of the reinforcing element (13).
10. Ski according to Claim 7, characterized in that the transverse section of the central core (23) has the form of an upturned Y, and this core comprises an upper vertical web (23a) extending as far as the middle of a horizontal flange (23b) glued beneath the edge (4), two inclined lower branches (23c, 23d) issuing from the vertical web (23a), extending downwardly and outwardly and which join respective horizontal flanges (23e, 23f) extending outwardly and glued to the reinforcing element (13).
11. Ski according to Claim 7, characterized in that the transverse section of the inner core is in omega form and this core is constituted by two halves substantially symmetrical with respect to plane P, each having substantially the shape of a Z, the upper horizontal flanges (24a, 24b), extending towards plane (P), of these two Z-shaped halves are superposed and glued to each other, beneath the edge (4), whilst the lower horizontal flanges (24c, 24d), extending outwardly, are glued to the reinforcing element (13), and vertical walls (24e, 24f) extend respectively between the horizontal flanges (24a, 24c) on the one hand and (24b, 24d) on the other hand.
12. Ski according to any one of Claims 6 to 11, characterized in that the reinforcing element (13) presents, in its central part, an inwardly projecting longitudinal rib (13a).
13. Ski according to any one of Claims 7 to 12, characterized in that the lower inclined lateral faces (7, 8) of the outer shell (11) extend downwardly by vertical edges (9, 10) inside which extend and are glued vertical raised edges (20, 21; 22, 23; 13b) of the core (12) or of the lower horizontal reinforcing element (13).
14. Ski according to Claim 13, characterized in that the inner core (12), with transverse section in omega form, comprises two lower horizontal flanges (18, 19) extending outwardly and terminating in raised edges (20, 21) extending vertically upwards.
15. Ski according to Claim 14, characterized in that the vertical raised edges (20, 21) of the lower horizontal flanges (18, 19) of the core (12) are glued directly to the edges (9, 10) of the outer shell (11).
16. Ski according to Claim 15, characterized in that the lower reinforcing element (13) terminates in raised edges (13b) extending upwardly and which are engaged between the vertical edges (9; 10) and the vertical raised edges (20, 21; 22, 23) of the flanges (18, 19) of the core (12), being glued together therewith.
17. Ski according to Claim 16, characterized in that the raised edges (22, 23) of the flanges (18, 19) of the core (12) have an upturned U shape so as to cap the vertical raised edges (13b) of the reinforcing element (13).
18. Ski according to any one of Claims 7 to 12, characterized in that the lower inclined lateral faces (7, 8) of the outer shell directly join the ends of the lower reinforcing element (13).
19. Ski according to any one of the preceding Claims, characterized in that the lower elementary section (3) has the form of any trapezium, in particular or isosceles, and the upper elementary section (2) has a square, rectangular or trapezoidal form.
20. Ski according to Claim 19, characterized in that the two elementary sections (2, 3) each have the form of an isosceles trapezium and they are joined to each other by a common base constituting the large base of the upper elementary trapezoidal section (2) and the small base of the lower elementary trapezoidal section (3).
21. Ski according to Claim 20, characterized in that the upper trapezoidal elementary section which constitutes an upper guiding rib (2), presents a horizontal upper face or edge (4) which is extended downwardly by two inclined lateral faces (5, 6) and symmetrical with respect to the vertical and longitudinal plane of symmetry (P) of the ski and the lower trapezoidal elementary section or base (3) comprises two inclined lateral faces (7, 8) extending downwardly the inclined lateral faces (5, 6) symmetrical with respect to the vertical plane (P), the lower inclined lateral faces (7, 8) of the base (3) being more inclined, with respect to the vertical and longitudinal plane (P), than the upper inclined faces (5, 6).
22. Ski according to Claim 21, characterized in that the angle of inclination of the lateral faces (5, 6) of the upper guiding rib (2), with respect to the vertical and longitudinal plane of symmetry (P) of the ski, varies from the front to the rear of the central bearing area (A).
23. Ski according to Claim 22, characterized in that, at the front of the central bearing area (A), i.e. where the front end of the shoe is fixed, the angle a formed by the inclined lateral faces (5, 6) with the vertical plane (P) varies from 0 to 10 degrees and it is preferably close to 5 degrees, whilst, in the rear part of the central bearing area (A), this angle is greater and it may vary from 20 to 40 degrees.
24. Ski according to either one of Claim 22 and 23, characterized in that the angle of inclination (b) of the lower inclined lateral faces (7, 8) of the base (3), with respect to the vertical and longitudinal plane (P), varies from 30 to 60 degrees.
25. Ski according to any one of Claims 1 to 17, characterized in that the upper and lower elementary sections (2) and (3) each have the form of any quadrilateral.

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