FR2670392A1 - Winter sports ski consisting of a base and a stiffener - Google Patents

Abstract

Ski consisting of a first lower assembly or base, the front end of which is raised in order to form the tip; and a second upper assembly or stiffener, the two assemblies being linked with each other via linking means produced by a flexible and/or partially rigid link.

Description

SKI FOR WINTER SPORTS CONSISTING OF A BASE AND A
STIFFENER
The present invention relates to a ski, such as an alpine ski, a cross-country ski, a monoski or a snowboard. It relates more particularly to an improvement in this type of skiing.

 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 in an optimal manner, taking into account the distribution of mechanical stresses during the use of 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 a tip, a rear part slightly raised in the heel, a central arched part. .

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

The present invention relates to improvements made to these skis in order to facilitate their manufacture which makes it possible to obtain the desired characteristics. due to the variety of parameters that can be chosen
The ski according to the invention consists of a first lower assembly or base, and a second upper assembly or stiffener, the two assemblies being linked to each other by connection means produced by a flexible connection and / or partially rigid.

 According to an additional characteristic, the stiffener has a length less than the length of the surface of the base in contact with the snow. It is advantageously between 50 and 80% of the length of the base.

 According to an advantageous arrangement the base and the stiffener are elongated beams whose height is variable along the ski to decrease towards the front and rear ends.

 According to one of the embodiments, the connection between the base and the stiffener is produced by a flexible interface, consisting of a sheet of elastic or viscoelastic material, and extends under the entire lower surface of the stiffener.

 According to another variant, the flexible connection is partial and extends only under part of the length of the stiffener.

 According to another variant, the connection between the base and the stiffener is a rigid connection and does not extend under the entire lower surface of the stiffener.

 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.

 Figure 1 is a side view of a first embodiment of a ski according to the invention.

 Figure 2 is a cross section along II-II of Figure 1.

 Figure 3 is a cross section along III-III of Figure 1.

 Figure 3a is a variant.

 Figure 4 is a side view showing the various components of the ski according to the first embodiment.

 Figures 5 and 6 are schematic views showing the ski in cross section and in two variants.

 Figures 7, 8, 9 and 10 are top views showing three embodiments of the stiffener.

 Figures 11 to 16 are side views showing different variants of the connecting means.

 Figures 11 and 12 show flexible partial connections.

 Figures 13 and 14 show rigid partial connections.

 Figures 15 and 16 show mixed connections, partially flexible and partially rigid.

 Figures 17 to 21 are variants showing in cross section and schematically other embodiments.

 Figures 22 and 23 are side views showing variants.

 FIG. 24 is a diagram representing the stiffness of a ski as a function of its flexion.

 FIG. 1 represents a ski according to a first embodiment according to the invention. It comprises a lower assembly or base (1) and an upper assembly or stiffener (2) Said stiffener (2) is disposed above the base (1) and linked to the latter by connecting means (3).

The base (1) is the element in contact with the snow and is in the form of an elongated beam (10) having its own distribution of thickness, width and therefore its own stiffness. This elongated beam also having a lower stiffness than that of a conventional ski, at least in its part covered by the stiffener (2)
The base (1) comprises a central part (113) slightly arched, having a lower sliding surface (114) and an upper surface (115). The central part (113) occupies most of the length of the base and is extended on the one hand at the front by an anterior part (116) raised to form the spatula (117) and on the other hand by a rear part (118) slightly raised to form the heel of the ski. The rear part (118) being relatively short and of low lift, and the front part (116) is longer and much more arched, as is known. per se and shown in the figures.

 The structure of the base (1) can be of the sandwich type or of the box type or of any other type. FIG. 2 shows a preferred structure comprising, a rigid upper reinforcement (101) in the form of a shell with a "U" section forming a top wall (102) and two side walls (103 and 104), covering a core ( 105), the assembly being closed at its lower part by a lower element (106) comprising the metal edges (107, 108), a sliding layer (109) generally made of polyethylene as well as lower reinforcing elements (110, 111). An upper surface layer (112) covers the upper reinforcement to form the decor of the base.

 The reinforcing layers (101,110,111) can be of any type such as layers of composite materials such as fiberglass, carbon fiber with epoxy or polyester resin, or a metal alloy.

The core (105) can be filled or unloaded foam, wood or aluminum honeycomb;
The surface layer providing the decoration may be made of polyamide. or other such as in thermoplastic material. It can be single layer or made up of several layers.

 According to the invention, the upper face (115) of the central part (113) of the base (1) is covered with a stiffener (2). This element is intended to complete the distribution of the stiffnesses of the base (1) so as to obtain the desired overall distribution. Said stiffener (2) can be of any kind, any shape and any structure.

 According to an advantageous arrangement, the stiffener (2) is in the form of an elongated part (20) also having its own distribution of thickness, width and therefore stiffness.

 In the embodiment given by way of example and represented in FIG. 3, the structure of the stiffener is of the box type and is formed of a core (201) disposed between an upper reinforcement (202) and a lower reinforcement (203 ). The stiffener can also consist of a simple profile made of a single material.

 The upper reinforcement (202) is covered with another additional reinforcement layer (204) in the shape of an inverted "U" and forming an upper wall (205) and two side walls (206,207). A surface layer (208) covers the top and the side faces of the stiffener (2) to form the finish and the decoration thereof.

 As previously for the base, the reinforcing layers of the stiffener can be of all types such as layers of composite materials such as fiberglass, carbon fiber, with epoxy or polyester resin. The core (201) can be filled or unloaded foam, wood or aluminum honeycomb. The surface layer providing the decoration can be made of polyamide.

 According to an advantageous arrangement, (Figure 4), the stiffener (2) has a length "L2" less than the length "L1" of the base (1). Thus, the front end (209) of the stiffener is located between the point (119) of spatula contact of the base and the front end (120) of the standardized area for mounting the fasteners. Similarly, the rear end (210) of the stiffener is located between the rear contact point (121) and the rear end (122) of the standardized area for mounting the fasteners. Thus, if the base (1) has a length "L1" of contact with the snow, the stiffener (2) has a length "L2" such that "L2" is less than "L1".

 For example, the length "L2" of the stiffener is between 50% and 80% of the length "L1". In addition, the relative longitudinal position of the stiffener (2) relative to the base (1) may for example be such that the middle (211) of the stiffener (2) is at the middle (123) of the length (L1 ) of contact of the base (1) with the snow. But it could be otherwise; thus the middle (211) of the stiffener (2) can be further forward (AV) or further back (AR) relative to the middle (123) of one base.

 As regards the width of the two elements, the stiffener (2) can have the same width as the width of the base (1), as shown more particularly in FIG. 3. But it can be otherwise; thus the stiffener (2) may have a width "12" less than the width "11" of the base (1) and thus be narrower than the latter, as shown diagrammatically in FIG. 5. Similarly, the stiffener (2) can be wider than the base (1) as shown in Figure 6.

 Note also that the width of the two base assemblies (1) and / or stiffener (2) can be constant or variable as shown in Figures 7, 8 and 9.

 FIG. 7 shows, in top view an embodiment of a ski according to which the width "12" of the stiffener (2) is variable and roughly follows the variation of the width "11" of the base (1 ).

 Figure 8 is a view similar to Figure 7 showing another embodiment in which the width "11" of the base (1) is variable while the width "12" of the stiffener is constant.

 FIG. 9 is another variant according to which the variation of the width "12" of the stiffener is opposite to that of the width "11" of the base; that is to say that when the width "11" of the base 1 increases, the width "12" of the stiffener 2 decreases.

 According to the embodiments of Figures 7 to 9 the variation of the width "12" of the stiffener is continuous, but it could be otherwise, as shown in Figure 10. According to this variant the stiffener 2 comprises in its central area (212) a narrowing in width to form two lateral clearances (213, 214) extending over a length "L'2" less than "L2"; the stiffener (2) thus comprising a central portion (215) of reduced width.

 The base (1) and the stiffener (2) are elongated parts of respective height "hl" and "h2". Of course in a cross section the two heights "h1" and "h2" can have the same value, but also be different. Thus, in a cross section h1 "can be greater or less than" h2 ". In addition," hl "and / or" h2 "can be constant depending on the longitudinal position where the measurement is made. However, to obtain a good distribution of the stiffness it is advantageous to vary one or the other of the heights "hl" or "h2" and even the two "h1" and "h2". Thus the stiffener can have its height "h2" which decreases forwards or backwards, even see both forwards and backwards as shown, as does the base.

 According to the invention the stiffener (2) is linked to the base (1) by connection means (3) such that the connection between the two elements is flexible and / or partially rigid.

 The embodiment shown in Figures 1, 2 and 3 shows an example where the connection (3) between the two base assemblies (1) and stiffener (2) is completely flexible. To this end, the connecting means (3) are produced by a flexible interface (30) arranged between the two assemblies, over the entire length of the stiffener. The interface therefore has a width "12" equal to that of the stiffener (2) and a length "L2" equal to that of the latter.

 The interface (30) is produced by a layer of a flexible material of the elastic type, and in particular of the viscoelastic type, of thickness from 0.1 to 5 mm, which is glued or welded on the one hand to the upper surface. (115) of the base (1) and on the other hand under the lower surface (216) of the stiffener.

The material used can be elastic with a hardness of 10 to 85 shores A or viscoelastic material with a modulus of elasticity of 15 to 160 megapascal, a hardness of 50 to 95 shores A and a damping value of 0 , 13-0.72. Of course these data are only examples of implementation., And for a temperature of 20 degrees and a frequency of 15 hertz
The interface (30) is fixed to the base (1) and the stiffener (2) is produced either by a thermosetting resin of the polyester, vinylester or polyurethane epoxy type or a thermoplastic film, or any other means.

 The flexible connection according to the embodiment previously described is total and extends under the entire length (L2) of the stiffener (2), but it can be otherwise. In fact, the flexible connection can only be partial and not extend under the entire length of the stiffener (2) as shown in FIGS. 11 and 12.

 FIG. 11 therefore represents a first variant according to which the connection (3) is flexible and partial, and is produced by two flexible interfaces, a first flexible front interface (31) and a second flexible rear interface (32) disposed respectively under the front end (209) and rear end (210) of the stiffener (2).

 FIG. 12 represents a second variant according to which the flexible connection (3) is produced by a flexible central interface (33) disposed between the base (1) and the stiffener (2) in the central zone of the ski and the length of which " L3 "is less than the length" L2 "of said stiffener, to constitute a partial flexible connection.

 According to other variants, the connection (3) between the base (1) and the stiffener (2) is partially rigid; that is to say that the connection, when it is rigid, does not extend under the entire surface of the stiffener (2) as shown in FIGS. 13 and 14.

 FIG. 13 shows a variant according to which the connection (3) is partial and rigid; that is to say that the stiffener (2) is rigidly connected by its central lower surface (218) to the base (1). Thus, only the central part (212) is fixed to the base (1) while the front part (219) and the rear part (220) are free.

 Figure 14 shows another arrangement where the connection (3) is rigid and partial. According to this arrangement, only the front and rear ends (209 and 210) of the stiffener (2) are fixed to the base (1) to leave the central area (212) free.

 The rigid connection (3) can be obtained by any means such as bonding, by mechanical connection such as screws or rivets or even by welding, in particular by ultrasound or by vibration.

 Of course the connection (3) between the base (1) and its stiffener (2) can be mixed, that is to say partly flexible and partly rigid as shown in FIG. 15.

 Thus, according to the variant of FIG. 15, the central zone of the ski comprises a flexible central link (33), while the front and rear ends (209 and 210) of the stiffener are fixed to the base (1) by two partial links , rigid, a first rigid link or front link (35) and a second rigid link or rear link (36).

 According to the variant of Figure 16 the arrangement is reverse. Thus, the rigid partial connection (34) is in the center as according to the variant of FIG. 13 but the front (219) and rear (220) parts of the stiffener (2) are linked to the base by flexible partial connections, a first flexible front link (31) and a second flexible rear link (32). The rigid central link (34) can be obtained by a downward projection from the stiffener or a central intermediate wedge or central rigid interface (340).

 According to the embodiment previously described, the upper surface (115) of the base is a surface whose generator is parallel to the lower sliding surface (114). But it could be conceived that the upper surface (115) is oblique and inclined as shown in FIG. 17 where the connection interface (3) is inclined either towards the inside of the ski, or towards the outside.

 Figures 18, 19 and 20 are schematic views in cross section of three other alternative forms of the interface.

 According to these different variants, the interface area is not flat but has a complex shape. According to the variant of Figure 18 the surface of the interface (3) is curved. According to the variant of Figure 19 the base (1) comprises a longitudinal hollow profile and the lower surface (216) of the stiffener (2) comprises a corresponding projecting profile. The arrangement shown in Figure 20 is reversed. Thus the base (1) comprises on the top a projecting profile and the lower surface (216) of the stiffener comprises a corresponding hollow profile.

 According to the previous embodiment, the lower surface (216) of the stiffener (2) has a shape complementary to the upper surface (115) of the base, and this at least at the connection, but it could be otherwise as is shown in the variant of FIG. 21 according to which it is the connection (3) which ensures the form cooperation, on the one hand with the base (1) at its lower surface, and on the other hand with the stiffener ( 2) at its upper surface.

 Note that the surface layer (112) of the base (1) can extend over the entire length thereof, including in the area of the connection or only in areas where there is no said connection (3).

 According to Figures 1, 2 and 3, it can be seen that the surface layer (112) is interrupted at the level of the connection. Thus the flexible connection and therefore the interface (30) is directly fixed on the upper reinforcement (101) of the base.

 FIG. 3a shows a variant according to which the surface layer (112) of the base extends even in the region of the connection. Thus the interface (30) is fixed on the surface layer (112) of said base (1).

 The stiffness of the stiffener (2) can be equal to that of the base (1), but it can be different and in particular equal to 150% of the latter.

 Figures 22 and 23 show variants according to which the stiffener (2) mounted on a flexible interface is retained longitudinally relative to the base (1). For this purpose the base (1) comprises two stops, a first front stop (130), and a second rear stop (131). Figure 22 is an embodiment where the stiffener is somehow embedded in the base. Figure 23 is another embodiment.

 The embodiments of FIGS. 12 and 13 make it possible to obtain a ski whose rigidity varies non-linearly with the deformation of the ski. This ski reacts differently depending on the speed and the amplitude of the flexions Indeed at rest and during low flexions, given the presence of the front (ea) and rear (er) spaces. The base is not in contact with the ends of the stiffener. On the other hand, from a certain bending, there is contact and action of the stiffener on the base. FIG. 24 schematically represents the curve of the stiffness of the ski as a function of the flexion thereof.

 It may also be noted, that the flexible connection produced with an elastic interface and produced with a sheet may be such that said sheet has a constant or variable thickness. For example, being increasingly thick towards the front or vice versa, or even thicker both forwards and backwards. One could also conceive of the use of a layer of flexible material whose properties are such that the stiffness is not constant throughout this layer. Indeed it could be more flexible at the front or vice versa.

 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 as well as their combinations and other variants are also possible without departing from the scope of the invention.

Claims (36)

 1. Ski formed by a first lower assembly or base (1), the front end of which is raised to form the tip (117); and a second upper assembly or stiffener (2), the two assemblies being connected to each other by connection means (3,30,31,32,33,34,35,36,340) produced by a flexible connection and / or partially rigid.  2. Ski according to claim 1, characterized in that the stiffener (2) has a length "L2" less than the length "L1" of the surface of the base (1) in contact with the snow.  3 .. Ski according to claim 2, characterized in that the length "L2" of the stiffener is between 50 and 80% of the length "him".  4. Ski according to claim 3, characterized in that the front end (209) of the stiffener (2) is located between the tip contact area (119) of the base and the front end (120) of the area mounting fixings.  5. Ski according to claim 3, characterized in that the rear end (210) of the stiffener (2) is located between the heel contact zone (121) of the base and the rear end (122) of the zone mounting fixings.  6. Ski according to any one of the preceding claims, characterized in that the middle (211) of the stiffener (2) is located at the middle (123) of the area in contact with the snow from the base.  7. Ski according to any one of claims 1 to 5, characterized in that the middle (211) of the stiffener (2) is located in front of the middle (123) of the area in contact with the snow from the base.  8. Ski according to any one of claims I to 5, characterized in that the middle (211) of the stiffener (2) is located behind the middle (123) of the area in contact with the snow from the base.  9. Ski according to any one of the preceding claims, characterized in that the width "12" of the stiffener. (2) is equal to, less than or greater than the width "11" of the base (1).  10. Ski according to claim 9, characterized in that the width "12" of the stiffener. (2) is constant.  11. Ski according to claim 9 characterized in that the width "12" of the stiffener. (2) is variable and changes as a function of the longitudinal position.  12. Ski according to claim 11 characterized in that the variation of the width "12" of the stiffener is continuous.  13. Ski according to any one of the preceding claims, characterized in that the base (1) and / or the stiffener (2) is an elongated beam.  14. Ski according to claim 13, characterized in that the height "hl" of the base (1) and / or the height "h2" of the stiffener is constant.  15. Ski according to claim 13, characterized in that the height "hl" of the base (1) and / or the height "h2" of the stiffener is variable.  16. Ski according to claim 15, characterized in that the height "h2" of the stiffener decreases towards the front.  17. Ski according to claim 16, characterized in that the height "h2" of the stiffener decreases towards the rear.  18. Ski according to any one of the preceding claims, characterized in that the base (1) is a beam constituted by a core (105) disposed between two reinforcements, a first upper reinforcement (101) and a second lower reinforcement (110,111 ), and comprises a sliding layer (109) laterally comprising two lateral metal edges (107, 108), said upper reinforcement being covered, at least in part by a surface layer (112).  19. Ski according to claim 18, characterized in that the surface layer (112) of the base (1) is interrupted at the level of the stiffener (2).  20. Ski according to any one of the preceding claims, characterized in that the stiffener (2) is a beam constituted by a core (201) disposed between two reinforcements, a first upper reinforcement (204) and a second lower reinforcement (203 ), said upper reinforcement being covered with a surface layer (208).  21. Ski according to any one of the preceding claims, characterized in that the connection (3) between the base (1) and the stiffener (2) is produced by a flexible interface (30,31,32,33).  22. Ski according to claim 21, characterized in that the interface consists of a sheet of elastic or viscoelastic material.  23. Ski according to claim 22, characterized in that the sheet of flexible material has a variable hardness.  24. Ski according to claim 22 or 23, characterized in that the sheet of flexible material has a variable thickness.  25. Ski according to any one of claims 22 to 24, characterized in that the sheet of elastic or visco material has a thickness between 0.1 and 5mm.  26. Ski according to any one of claims 21 to 25, characterized in that the flexible connection (30,31,32,33) extends under the entire lower surface (216) of the stiffener (2).  27. Ski according to any one of claims 21 to 25, characterized in that the flexible connection is partial, and extends only under a part of the stiffener (2).  28. Ski according to any one of claims 21 to 25, characterized in that the interface (33) is disposed only under the middle zone of the stiffener over a length "L3" less than the length "L2" of the stiffener.  29. Ski according to claim 27, characterized in that the flexible connection is constituted by two interfaces, a first flexible front interface (31) disposed under the front end (209) of the stiffener (2) and a second flexible rear interface ( 32) disposed under the rear end (210) of said stiffener (2).  30. Ski according to any one of the preceding claims, characterized in that the connection (3) between the base (1) and the stiffener (2) is a rigid connection (34,35,36) and does not extend not under the entire lower surface of the stiffener.  31. Ski according to claim 30, characterized in that the stiffener (2) is rigidly fixed by its central zone (34) on the upper middle surface of the base.  32. Ski according to claim 30, characterized in that the front and rear ends (209,210) of the stiffener (2) are fixed to the base (1).  33. Ski according to any one of the preceding claims, characterized in that the upper surface (115) of the base (1) cooperates with the lower surface (216) of the stiffener (2) by complementary shapes.  34. Ski according to claim 33, characterized in that the upper surface of the base (1) comprises a longitudinal hollow profile or a longitudinal projecting profile and the lower surface of the stiffener respectively comprise a corresponding projecting profile or a profile in corresponding hollow.  35. Ski according to any one of claims 1 to 32, characterized in that the shape of the lower surface (216) of the stiffener (2) is different from the upper surface (115) of the base (1) and the connection comprises at its lower surface a shape complementary to the shape of the upper surface of the base while the upper surface has a shape complementary to the shape of the lower surface of the stiffener (2).  36. Ski according to any one of claims there 30 and 33 to 35, characterized in that one of the connections connecting the ends of the stiffener (2) to the base (1) is flexible, while the other is rigid.