Patent Application
20100148472
This application claims priority under 35 U.S.C. §119 of French Patent Application No. 08 06872, filed on Dec. 8, 2008, the disclosure of which is hereby incorporated by reference thereto in its entirety.
1. Field of the Invention
The invention relates to an alpine ski used, in particular, for the practice of “freestyle” skiing, i.e., for performing various maneuvers, or tricks, such as jumps or glides in an adapted environment which includes rails, for example, on which a skier can slide his/her skis transverse to the longitudinal axis thereof.
2. Description of Background and Other Information
It is known from U.S. Pat. No. 7,341,271 to configure a ski to have zones with variable flexional rigidity in order to obtain an efficient transmission of forces when the ski adopts a curved configuration, with a substantially constant radius of curvature over its length, as shown in the drawings of this patent.
The document FR 2 042 420 also discloses a ski having a zone with a reduced flexional strength. In this case, the objective is to make it easier to ski using a lateral inclination technique, which requires occupying a rear position. As described in the preamble of the document FR 2 042 420, a rotation occurs between the front portion and the rear portion of the ski, around a point located immediately behind the middle of ski, i.e., in the area of the rear binding, or heel piece.
For the practice of freestyle, a skier sometimes wants to perform a trick in which the skier slides the front or rear end, i.e., the shovel or spatula, of the skis on a rail. In this case, the skis of the prior art flex evenly over their entire lengths, so that it is difficult for a skier to reproduce the same maneuver several times. Indeed, depending upon the positioning of the ski with respect to the rail, it is not possible to anticipate the behavior of the ski with a sufficient degree of accuracy.
The invention improves upon characteristics and abilities of known skis, overcoming, or at least lessening, the aforementioned disadvantages and, more particularly, the invention encompasses an alpine ski that facilitates the performance of certain freestyle maneuvers, or tricks, and that facilitates the reproducibility of such freestyle maneuvers/tricks.
To this end, the invention is directed to an alpine ski having binding mounting zone centered on a mounting point, and a unique zone of deformation in flexion between the mounting zone and at least one end of the ski.
In the context of the Invention, a deformation in flexion of the ski is a flexion deformation along a longitudinal axis or direction of the ski.
According to the invention, the particular flexion deformation zone, the location of which is known to the skier, makes it possible to obtain a localized and reproducible deformation of the ski in that zone. The front end, or spatula or shovel, sometimes simply referred to as the tip, defined between this zone and the extreme end of the ski, on the one hand, and the zone for mounting the binding, on the other hand, practically does not flex. Thus, depending upon the characteristics of the particular deformation zone, the skier can obtain the same behavior several successive times, in particular while performing maneuvers, or tricks, known as a “nose press” or “tail press”.
According to advantageous, but non-limiting aspects of the invention, such a ski can incorporate one or several of the following characteristics, taken in any technically acceptable combination:
The invention will be better understood, and other advantages thereof will become more clearly apparent, from the following description of seven embodiments of an alpine ski, given only by way example, and in reference to the annexed drawings, in which:
The ski 1 shown in
The waist width I1 of the ski 1 is greater than 66 mm, or greater than 75 mm in a particular embodiment. The zone 6 is centered on a mounting point A6 defined according to the NF ISO 8364 standard. The mounting zone has an axial length L6.
A length or a dimension is referred to as “axial” when it extends parallel to the axis X1, whereas it is referred to as “transverse” when it extends perpendicular to this axis. The waist width I1 is a transverse width.
The zone 6 has a minimal thickness e6 ranging between 8 and 25 mm over its length L6. The thickness of the ski in the zone 6 is, for a desired rigidity, a function of its width in this same zone.
The ski 1 has an upper surface 8 and a sole 10.
A particular deformation zone Z1 of the ski 1 is arranged between the mounting zone 6 and the front end 2, i.e., forward of the zone 6. A second particular deformation zone Z2 is arranged between the zone 6 and the rear end 4, i.e., at the rear of the zone 6.
Each of the particular flexion deformation zones Z1 and Z2 is manifested by a localized reduction in the thickness of the ski 1.
These zones Z1 and Z2 are provided to adopt a generally dihedral configuration when the ski is subjected to a deformation force in flexion. Such is particularly the case when a skier performs a maneuver known as a “nose press”, i.e., with the front section, or shovel or spatula, of the ski supported on a rail, in which case the zone Z1 becomes deformed. Similarly, the zone Z2 becomes deformed when the user performs a maneuver known as a “tail press”, i.e., the rear section, or shovel or spatula, of the ski is supported on the rail.
As seen more particularly in
A finish layer 15, commonly referred to as the “top”, is affixed on, or above, the reinforcement 12 and bears the decoration of the ski. It can be made of an assembly of a plurality, or several, layers.
The thickness e16 of the core 16 is locally reduced in order to form the zone Z1, so that the total thickness e1 of the ski 1 in the zone Z1 has a minimal value ranging between 6 and 8 mm, i.e., a value substantially less than that of the thickness e6. The thickness e1 corresponds to the sum of the minimal thickness e16 and of the thicknesses of the reinforcements 12 and 14 and of the sole 10, these two thicknesses being substantially constant over the length of the ski 1.
In practice, the minimal value the thickness e16 is greater than 1.5 mm to limit the risk of rupture of the core 16 in the zone Z1. In an alternative, however, one can provide an interruption of the core 16 in the area of the zone Z1 and/or zone Z2, which makes it possible to put the upper 12 and lower 14 reinforcements in contact, in order to limit the constraints in these reinforcements.
The front shovel 18, or spatula, of the ski 1 is defined herein as being the portion of the ski extending between the zone Z1 and the front end 2, or tip. The minimal thickness e18 of the shovel 18 is between 8.5 and 11 mm. This thickness is greater than in conventional skis, in which it has a value generally ranging between 5 and 7.5 mm. This needs to be brought closer because the shovel 18 can be substantially more rigid than in conventional skis, because the flexing of the ski occurs primarily in the area of the zones Z1 and Z2.
In practice, the rigidity of the shovel 18 is dependent upon the distance between the reinforcements 12 and 14, i.e., upon the thickness of the core 16. In the case in which the shovel includes a top or layer that is spaced from the upper reinforcement, with a possible interposition of a fitting or spacer, the rigidity of the shovel is not actually affected because the distance between the reinforcements remains similar to that of the illustrated embodiment. For example, the shovel can have a total thickness of 16 mm by having the same rigidity as that of the shovel 18 shown in the drawing figures, if the thickness of the sandwich comprised of the elements 12, 14, and 16 has a minimal value ranging between 8.5 mm and 11 mm.
The rear shovel or spatula 19 of the ski 1 is defined between the zone Z2 and the rear end 4, or, in the illustrated twin tip ski, the rear tip. The minimal thickness e19 of the shovel 19 has same value as the thickness e18.
A straight line Δ1, perpendicular to the axis X1, is positioned where the thickness of the ski begins to decrease by moving away from the point A6, in relation to the value the thickness e6. A straight line Δ′1, perpendicular to the axis X1, is positioned where the thickness of the ski 1 begins to decrease, by moving away from the end 2, in relation to the value the thickness e16. The zone Z1 is defined between the straight lines Δ1 and Δ′1.
A central point A1 of the zone Z1 is equidistant from the straight lines Δ1 and Δ′1 and is located on the surface 8, halfway between the right and left lateral edges 20 and 22 of the ski 1. This point can be considered as a softening point, or a weakened point, of the ski in the zone Z1.
The axial length L1 of the zone Z1, i.e., the axial distance between the straight lines Δ1 and Δ′1, has a value ranging between 150 and 200 mm. The axial distance D1 between the straight line Δ1 and the mounting point A6 has a value ranging between 285 and 385 mm. The axial distance D′1 between the points A1 and A6 is between 360 and 480 mm.
The zone Z1 should be sufficiently spaced from the middle of the ski so that the particular deformation zone has a limited effect on the normal performance or functioning of the ski, i.e., such as that while traversing a flat trail, without any particular trick or maneuver being performed by the skier. In practice, as shown in
The zone Z2 is substantially symmetrical with the zone Zi with respect to the mounting point A6. It extends between two straight lines Δ2 and Δ′2 perpendicular to the axis X1, and there is a central point A2, or softening point, of the zone Z2 on the surface 8. The axial length L2 of the zone Z2 is between 150 and 200 mm, and the straight line Δ2 extends a distance D2, ranging between 285 and 365 mm with respect to the mounting point A6. The distance D′2 between the points A2 and A6 is between 360 and 480 mm.
In an alternative embodiment, the zone Z2 may not be at the same distance from the point A6 as the zone Z1. In particular, zones with various lengths can be provided along the axis X1, between the mounting zone 6 and the zones Z1 and Z2.
The lengths L1 and L2 are not necessarily equal, just as the lengths D1 and D2, on the one hand, and D′1 and D′2, on the other hand.
The ski 1 includes a single particular deformation zone Z1 between the mounting zone 6 and the end 2, so that the ski 1 is capable of becoming deformed in only one zone between the front of the skier's boot and the front end of the ski. Similarly, a single particular deformation zone is provided between the mounting zone 6 and the rear end 4, so that the skier knows that the ski can become deformed in only one zone between the rear of the boot and the rear end of the ski.
In view of the existence of the zones Z1 and Z2, and of the relative rigidity of the mounting zone 6 and of the shovels 18 and 19, the flexing behavior of the ski 1 is reproducible, i.e., predictable, which makes it easier for the skier to control the ski, including controlling the ski during the performance of elaborate freestyle tricks.
This behavior can be characterized by a measurement of the flexion properties of the ski 1 when a given force is exerted on the ski, which is supported on two rods 202 and 204, each having a circular cross section, the centers of which are spaced from one another by an axial distance d200 equal to 400 mm, and which are arranged under the sole 10 of the ski, symmetrically on both sides of the zone Z1.
When the ski 1 is supported on the two rods 202 and 204 under the effect of its weight, its sole 10 is substantially flat in the zone Z1, and its trace in the plane of
When a load E1 perpendicular to the sole 10 is exerted in the center of the zone Z1, i.e., in the vicinity of the point A1, and in a direction extending from the surface 8 towards the sole 10, while the ski 1 is in support on the rods 202 and 204, as explained hereinabove, the ski flexes in the zone Z1 and adopts a generally dihedral configuration in the vicinity of this zone, as shown in
The bending deflection f of the zone Z1 is shown in the configuration of
The thicknesses and distances mentioned hereinabove are such that, for a static load E1 with an intensity equal to 900 Newtons, i.e., corresponding to a weight of approximately 90 kg, and a distance d200 equal to 400 mm, the deflection f is greater than 13 mm.
These thicknesses and distances, for particular embodiments, can be selected by digital simulation or tests on samples, so that this deflection is greater than 15 mm.
The zone Z2 is also configured so that the deflection defined under the same conditions has a value greater than 13 mm, and 15 mm in a particular embodiment.
This confers a good behavior for the ski 1 when the skier performs tricks, or maneuvers, such as mentioned hereinabove.
Moreover, when the skier skis in powder snow, the flexion zone Z1 enables the shovel 18 to pivot upwards, about an axis perpendicular to the axis X1 and passing in the vicinity of the point A1, which makes it easier for the ski 1 to lift off.
In the second to seventh embodiments shown in
The ski 1 of
An elastomeric block 34 is arranged between the plate 30 and the upper surface 8 of the ski 1. The plate 30 makes it possible to maintain the longitudinal rigidity of the ski, i.e., related to longitudinal flexion, to a value comparable to that of a conventional ski, as long as the plate 30 does not buckle. In other words, the ski becomes slightly deformed or does not become deformed in the zone Z1 as long as the bending stress is not sufficient to cause the plate 30 to buckle. With respect to the embodiment of
The elastomeric block 34 guarantees that if the plate 30 buckles, it becomes deformed upwards and not in the direction of the sole 10 of the ski 1. This block is however optional insofar as a preferred buckling direction for the plate 30 can be obtained by means of an adapted configuration thereof.
In this embodiment, the shovel 18 is not thicker than in a conventional ski. It has a thickness e18 ranging between 5 mm and 7.5 mm. Indeed, one can consider that the plate 30 at least partially compensates for the loss of rigidity of the ski, whereas, in the first embodiment, it is the thick shovels that fulfill this function.
In the embodiment of
To make the ski more lively, i.e., to provide the ski with more reactivity or with pep, a spring 48 is inserted between the end 44 of the blade 40 and an abutment 49 fixed with respect to the ski 1. This spring exerts on the end 44 a force E2 that is directed towards the screw 42, which can enable the blade 44 to restore the energy of the spring after bending, and to provide more rebound to the ski.
In the embodiment of
According to one advantageous aspect of a particular embodiment of the invention, an elastomeric wedge or spacer can be positioned between the surfaces 52 and 62, which improves the bending progressiveness in the zone Z1 and which yields better performance when the ski snaps back.
In the embodiment of
The lengths of the blades 70, taken parallel to the thickness e1 of the ski 1, increases and then decreases over the length of the zone Z1 taken parallel to the axis X1. In an alternative, all of the blades 70 can have the same length.
In the embodiment of
In the embodiment of
An upper reinforcement 104, visible through a cut-away section of
The deformation zones Z1 and Z2 of the skis of the embodiments of
The technical features of the various embodiments mentioned hereinabove can be combined with one another. For example, a counter-deflection stop blade can be used in the embodiment of
The invention has been described in relation to a twin tip freestyle ski. It however applies to other types of skis, in particular a ski of which only the front tip is raised, i.e., the tail having an otherwise conventional shape.
The embodiments and alternative embodiments have been described hereinabove by way of example, and the invention encompasses any and all equivalent embodiments.
The invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 08.06872 | Dec 2008 | FR | national |
