EP0781578A1 - Downhill ski fitted with a device for adapting the transversal position of the binding to the forces applied by the skier - Google Patents

Abstract

The ski has an intermediate platform (10) to which the binding is fixed. The lower surface of the platform has longitudinal blocks (13,14) which are trapezoidal in cross section. Their inclined surfaces (13,16) slide on the inclined surfaces (15,17) of complementary blocks (19,20) on a lower plate (11), fixed to the upper surface (3) of the ski. When there is no weight on the ski the blocks are brought to their rest position by a coil spring (22), between a stop on the end of the platform and the end block (20). An elastic block (12) is between the platform and the lower plate.

Description

Technical area

The invention relates to the field of piste skiing, more precisely it relates to a ski which has a device making it possible to shift the position of the skier's foot relative to the median longitudinal axis of the ski according to the intensity of the pulses generated by the skier, when taking the edges.

Previous techniques

As is known, during the impulse necessary to initiate a turn when practicing piste skiing, the skier exerts a force directed towards the surface of the sole. Depending on the duration and especially the intensity of these pulses, we sometimes obtain long turns, characteristic of the practice of giant slalom, or sometimes short turns observed in the practice of special slalom, which require support forces. more important but of shorter duration. Typically, it has been measured that these vertical pulses can reach 500 daN, for a 80 kg skier, that is to say that these pulses can exceed six times the weight of the skier.

It has been proposed to adapt the skis for the different techniques for which they are intended, by drawing structures, but also dimension lines specific to each of these versions. It will be recalled that the dimension line of a ski is according to a standardized definition, the line which represents the lateral contour of the sliding surface of the ski in the zone situated between the point of maximum front width and the point of rear maximum width. This line is defined by the lower edges. Thus, the dimension line of a ski intended for special slalom is generally more hollow than the dimension line of a ski for giant slalom. Approximately, we can consider that a hollowed out line of dimensions brings the lower edge closer to the axis longitudinal median of the ski, which decreases the torque as well as the time necessary for the passage from one edge to the other and therefore increases the speed of execution.

It has already been proposed in patent FR-A-2,660,567 corresponding to US Pat. No. 5,286,051 to shift the position of the foot transversely relative to the ski by implanting the bindings in an offset manner relative to the median longitudinal axis of the ski. Unfortunately, this offset location is not ideal in all conditions of use of a ski.

Furthermore, it has been proposed in document DE 38 32 290 to equip a cross-country ski with a device allowing the displacement of the binding during the practice of the skater's step. More specifically, this device consists of a platform able to move transversely on the upper face of the ski, and connected to the latter by means of compression springs. Thus, during the propulsion phases when the skier exerts a lateral and transverse force, parallel to the upper face of the ski, the platform moves by compressing the aforementioned springs. The apparent hardness of the ski is therefore modified, which improves the comfort of the skier. In no case can this solution be transposed to the field of piste skiing. Indeed, such a device mounted on an alpine ski would cause the foot to float relative to the board, which would result in the risk of crossing the skis and falling.

The problem that the invention seeks to solve is to allow the dynamic adaptation of the transverse position of the binding as a function of the intensity of the pulses applied by the skier on the ski.

Statement of the invention

• une face inférieure de glisse, bordée par des arêtes, constituant respectivement une carre externe et une carre interne ladite carre interne correspondant aux deux carres en regard lorsque les deux skis d'une paire sont posés à plat l'un à côté de l'autre ;
• une face supérieure destinée à recevoir dans la zone patin un dispositif intermédiaire constitué d'au moins une plateforme sur laquelle est montée une fixation de sécurité composée d'une butée et d'une talonnière, le plan longitudinal médian de la plateforme étant confondu avec le plan longitudinal médian de la planche de glisse, lorsque le dispositif supporte le poids du skieur, ledit dispositif intermédiaire comportant :
  • * des moyens aptes à décaler sous l'effet d'une force la position du plan longitudinal médian de la plateforme par rapport au plan longitudinal médian de la planche de ski ;
  • * et au moins un organe de rappel destiné, en l'absence de ladite force, à ramener en position confondue les deux plans longitudinaux médians, respectivement de la plateforme et de la planche de glisse ;

The invention relates to a piste ski having:

• a lower sliding face, bordered by edges, respectively constituting an outer edge and an inner edge, said inner edge corresponding to the two facing edges when the two skis of a pair are placed flat next to each other ;
• an upper face intended to receive in the skate area an intermediate device consisting of at least one platform on which is mounted a safety binding composed of a stop and a heel piece, the median longitudinal plane of the platform being coincident with the median longitudinal plane of the gliding board, when the device supports the weight of the skier, said intermediate device comprising:
  • * means capable of shifting under the effect of a force the position of the median longitudinal plane of the platform relative to the median longitudinal plane of the ski board;
  • * and at least one return member intended, in the absence of said force, to bring the two median longitudinal planes, respectively of the platform and of the gliding board, back to the same position;

This ski is characterized in that said offset means act under the effect of a force directed perpendicular to the upper face of the gliding board, causing a lateral offset from the median longitudinal plane of the platform, said lateral offset being a function increasing of said force.

In other words, thanks to the device according to the invention, the binding installed on the characteristic platform has a displacement capacity relative to the ski. The intermediate device is arranged in such a way that when the skier exerts a vertical impulse, the latter causes a modification of the position of the platform relative to the upper face of the ski. This displacement is an increasing function of the intensity of the impulse exerted by the skier, that is to say, the offset is greater the greater the force applied by the skier.

Thus, in one embodiment, when the skier enters a turn, the thrust that he produces, directed towards the sole of the ski, causes the shift of his boot towards the inside of the ski. The internal edge is thus found in a position closer to the underside of the boot, which promotes the dynamic behavior of the ski. Furthermore, in another embodiment, this characteristic impulse can cause the platform to pivot relative to the upper face of the ski, resulting in the fact that the ski turns at a greater angle than the boot in order to obtain an oversteer effect making it possible to accentuate the closure of the turn.

Advantageously in practice, the intermediate device comprises means for adjusting the threshold for implementing the shifting means.

In other words, the intermediate device produces its effects only from a pulse intensity, therefore from an adjustable force depending in particular on the weight of the skier.

According to a first fundamental mode of operation of the invention, the means capable of modifying the position of the median plane of the platform cause its transverse translation in the direction of the internal edge, under the effect of a crushing force directed towards the upper face of the ski. In other words, according to this first principle, the turn initiation pulse causes the foot to shift inward, in a direction of movement substantially perpendicular to the longitudinal plane of the ski. The axis of the boot remains parallel to the axis of the ski. The internal edge is found slightly offset under the shoe, which allows, as desired, to reduce the switching time from one edge to another.

In a practical embodiment of this first operating principle, the means intended to bring about the transverse translation of the platform consist of at least one ramp inclined downwards in the direction of the internal edge, in contact with at least one stop. , also inclined, each located respectively on the platform and on the upper face of the ski.

In other words, the cam surfaces arranged opposite between the platform and the ski channel the impulse and convert part of it into transverse displacement.

Advantageously in practice, the stop can be constituted by an inclined ramp, or a cylindrical roller whose axis of revolution is parallel to the longitudinal axis of the ski.

According to a second embodiment of this first operating principle, the means intended to allow the transverse translation of the longitudinal plane of the platform consist of at least two link arms articulated at their upper and lower ends respectively under the platform and on one of the faces of the ski, around axes parallel to the longitudinal axis of the ski.

In other words, the platform is connected for example to the upper face of the ski by a number of arms which allow, during a vertical impulse, the pivoting of the longitudinal axis of the platform relative to the longitudinal axis of the ski , by a deformable parallelogram effect.

Generally, the return members are constituted by studs made of elastic material, or by elastic spring leaves, made of metal or other, or even by helical coil springs.

According to a third embodiment of this first operating principle, the means intended to allow the transverse translation of the longitudinal plane of the platform consist of at least one elastic blade disposed between the platform and the upper surface of the ski, said blade being oriented towards the underside of the ski and towards the outer edge.

Thus, in this alternative embodiment, the platform is connected to the upper surface of the ski by at least one blade oriented in such a way that the depression of the platform results in a deformation of the elastic blade causing the transverse offset of the platform.

In this way, the elastic blade also ensures the return of the platform to its rest position when the pulse is completed. In an advantageous variant, the elastic blade can be embedded in an elastomeric stud which increases the return capacity of the intermediate device.

• une cale pentée solidaire de la face supérieure du ski, la pente de ladite cale étant orientée vers la carre interne ;
• un coin élastique interposé entre la cale pentée et la plateforme.

In a fifth embodiment of the first operating principle of the invention, the means capable of modifying the position of the median plane of the platform relative to the longitudinal plane of the ski consist of:

• a sloping wedge secured to the upper face of the ski, the slope of said wedge being oriented towards the internal edge;
• an elastic wedge interposed between the sloping wedge and the platform.

In this variant, the vertical impulse given to the platform causes the elastic wedge to be crushed and sheared. The difference in thickness of the elastic wedge due to the shape of the sloping wedge causes this shearing and therefore the transverse offset.

In a second operating principle, the invention uses the bending of the ski following a push exerted by the skier, to modify the position of the internal edge. However, we know that, to trigger a turn, you must put the ski on the inside edge and execute an overpressure. Under the effect of the ski's dimension line, in particular the narrowness of the ski at the level of the skate, as well as the overload, the board forming the ski bends downwards. Thus, the fictitious line connecting two fixed points located above the ski will become a rope all the shorter the smaller the radius of curvature of the ski. The invention therefore consists in using this approximation of these fixed points and in channeling it by means advantageously distributed on the upper face of the ski and under the platform.

According to a first embodiment of this second operating principle, the means intended to allow the transverse translation of the longitudinal plane of the platform consist of at least two guide grooves cooperating with two pins each arranged on the underside of the platform and on the upper face of the ski, the directions of the grooves converging on the side of the outer edge of the ski.

In an advantageous form, the intermediate device also comprises at least one additional groove, of direction parallel to the bisector of the directions of guide grooves.

In this way, this complementary groove whose direction is identical to that of the movement of the platform, ensures positive guidance of the transverse offset.

In a practical embodiment, the grooves are arranged on the platform and form through holes. The angle of inclination of these guide grooves relative to the longitudinal plane of the platform is between 30 ° and 60 °, and more favorably at 45 °.

In a second embodiment of this second operating principle, the means intended to allow the transverse translation of the longitudinal plane of the platform consist of a set of at least two journals secured to the upper face of the ski, said journals receiving cylindrical cams able to pivot eccentrically around the trunnions, said cams cooperating with complementary cylindrical housings formed in the platform, so that the bringing together of the trunnions causes the rotation of the cylindrical cams inside the housings, and therefore the lateral displacement of the platform.

In this way, as already said, during the impulse, the bending of the ski causes the approximation of fixed points, in this case the pins, integral with the upper face of the ski. The approximation of these pins results in the rotation of the eccentric cams and therefore the offset of the platform.

According to a third fundamental operating principle of the invention, the intermediate device comprises two platforms respectively supporting the stop and the heel of the safety binding, so as to cause the rotation of the longitudinal axis of the skier's foot, around an axis perpendicular to the upper face of the ski.

According to a first family of variants, the characteristic means of the invention are reversed from one platform to another, while in another family, these means cause a displacement in the same direction but cause an offset of amplitude different from one platform to another.

In other words, the invention in accordance with this third operating principle causes the binding to pivot by a different offset in the same or opposite direction of the stop and the heel piece.

In this way, during the turn, the direction of the longitudinal axis of the foot is distinguished from that of the longitudinal axis of the ski to obtain an oversteer effect making it possible to accentuate the closure of the turn.

• une première rampe inclinée vers le bas en direction de la carre interne, au contact avec au moins une première butée, chacune située respectivement sur la première demi-plateforme et sur la face supérieure du ski ;
• une seconde rampe inclinée vers le bas en direction de la carre externe, au contact avec au moins une seconde butée, chacune située respectivement sur la seconde demi-plateforme et sur la face supérieure du ski.

In a first embodiment of this third operating principle, the means intended to cause the rotation of the platform consist of at least:

• a first ramp inclined downwards in the direction of the internal edge, in contact with at least a first stop, each situated respectively on the first half-platform and on the upper face of the ski;
• a second ramp inclined downward towards the outer edge, in contact with at least a second stop, each located respectively on the second half-platform and on the upper face of the ski.

In other words, the intermediate device of this embodiment corresponds to two platforms already mentioned, associating facing cam surfaces, placed inversely with respect to each other.

In this way, during the pulse, the stop and the heel offset independently.

In an alternative embodiment, the inclination of the first and second inclined ramps are different, which ensures the pivoting of the longitudinal axis of the boot relative to that of the ski.

In a second embodiment of the invention operating on the principle of the rotation of the axis of the shoe, the binding is mounted on two independent platforms equipped with articulated arms as already mentioned. In order to obtain rotation by a different offset from one platform to another, the arms corresponding to each platform are inclined in the opposite direction or have different arm slopes.

Similarly, in a third embodiment of the invention operating on the principle of rotation, the two platforms are equipped with elastic blades as already mentioned. To ensure rotation, in a variant, the blades of the front platform are oriented towards the underside of the ski and towards the outer edge, and the blades of the rear platform are oriented towards the underside of the ski and towards the inner edge, while in another variant, the inclinations of the blades of the two platforms with respect to the upper face of the ski are different.

In a similar variant, the means intended to allow the transverse rotation of the longitudinal plane of the platform consist of a set of two journals integral with the upper face of the ski, the axis passing through the two journals not being parallel to the plane longitudinal of the ski, said journals receiving cylindrical cams able to pivot eccentrically around the journals, said cams cooperating with complementary cylindrical housings formed in the platform in a direction identical to that of the longitudinal axis of the ski, so that the approximation of the pins causes the rotation of the cylindrical cams inside the housings, and the displacement of the platform.

In this case, the approximation of each pin generates a different angle of rotation on each cylindrical cam therefore a pivoting of the platform relative to an axis perpendicular to the surface of the sole of the ski.

Generally, the return member is constituted in a known manner by a compression spring, an elastic pad or a leaf spring.

Furthermore, concerning the arrangement of the intermediate device with respect to the ski, in certain embodiments, the ski has a housing at the level of the skate area, inside of which said intermediate device is at least partially embedded.

In addition, to ensure certain independent assembly and manufacturing facilities, it may be advantageous for the means intended to allow the movement of the platform, which are integral with the upper face of the ski, to be mounted on a lower plate, itself in solidarity with the ski.

Brief description of the figures

The manner of carrying out the invention as well as all the advantages which ensue therefrom will emerge clearly from the description of the numerous embodiments which follow with the support of the appended figures among which:

Figures 1 and 2 are cross-sectional views of an alternative embodiment of the invention shown respectively in the rest position and under the effect of an impulse exerted by the skier.

FIG. 3 is also a cross-section view taken on a straight ski of an alternative embodiment of the form illustrated in FIG. 1.

Figures 4 and 5 are cross sections of alternative embodiments operating with articulated arms, respectively in the rest position and in the active position.

Figures 6 and 7 are cross sections of an embodiment operating with elastic blades, respectively in the rest position and in the active position.

Figures 8 and 9 are cross sections of a device according to the invention having a sloping wedge and an elastic wedge, respectively in the rest position and in the active position.

FIG. 10 is a side view of a ski showing in solid line a ski at rest and in dotted lines a ski undergoing bending under an impulse force.

Figures 11 and 12 are top views of a ski according to the invention comprising a light plate cooperating with pins fixed on the ski, respectively in the rest position and in the active position.

Figures 13 and 14 are top views of a ski in which the device according to the invention operates by means of eccentric cams, respectively in the rest position and in the active position.

FIG. 15 is a view in longitudinal section of the same device along the axis XV-XV 'of FIG. 13.

Figure 16 is a schematic top view of a ski having an intermediate device in two parts according to the invention respectively located under the heel and under the stop of the binding.

Figures 17 and 18 are two schematic sketches illustrating the different and independent movements of the platforms according to the invention and showing the rotation of the longitudinal axis of the boot relative to that of the ski.

Figures 19 and 20 are two top views of a ski equipped with a device according to the invention respectively in the rest position and in the active position in which the platform has pivoted relative to the ski.

Ways to realize the invention

As already said, the invention aims to equip a ski with an intermediate device allowing the modification of the position of the boot relative to the ski during the pulses for turning initiations.

As already said, this device can cause either the transverse translation of the boot relative to the ski, which causes the internal edge of the ski to shift relative to the internal face of the boot, which improves cornering. According to another principle, the intermediate device allows the rotation of the axis of the boot relative to the longitudinal axis of the ski causing an oversteer effect in which the tip tends to rotate more than the foot to register in a sharp turn.

First operating principle of the invention Example 1

In the embodiment illustrated in Figure 1, the pair of skis (1, 2) is shown in section, the ski (1) being the left ski and the ski (2) being the right ski. The plane (9) is the plane of symmetry of the pair. This is symmetrically equipped with an intermediate device according to the invention.

This device mainly consists of three parts, namely a platform (10) on which the binding rests, a lower plate (11) directly secured to the upper face (3) of the ski, and an elastomeric intermediate stud (12) forming a member reminder.

The platform (10) has on its lower face, longitudinal bearing surfaces (13, 14) with trapezoidal section. The inclined faces (15, 16) of these trapezoidal bearing surfaces (13, 14) are opposite with inclined faces (17, 18) of the bearing surfaces of complementary trapezoidal sections (19, 20) formed on the lower plate (11). The inclined slopes of these cam surfaces (15 - 18) are oriented downward and in the direction of the internal edge (4) of the ski.

Advantageously, these facing surfaces (15 - 18) can be covered with a layer intended to reduce the coefficient of friction, for example made of polytetrafluoroethylene.

Furthermore, this intermediate assembly comprises one or more return members constituted either by an elastomeric stud (12) or by metal helical springs (22) or with a leaf. These return members are arranged between the platform (10) and the lower plate (11), either in the central zone or in the lateral zones, bearing on a stop (21) formed for this purpose on one end of the platform (10).

The operation of this embodiment is easily understood from the view of FIGS. 1 and 2.

Under the effect of an impulse (F) generated by the skier towards the upper face (3) of the ski, the inclined slopes (15 - 18) of the trapezoidal cams slide over one another and cause lateral displacement ( E1-E2) and vertical (H1-H2) of the platform (10) in the direction (D) of the inner edge (4).

Obviously, the value of the displacement is a function of the slope given to the cam surfaces (15 - 18), of the coefficient of friction between these surfaces, and of the stiffness of the return device (12, 22).

As already said, these parameters can be advantageously adjusted to ensure optimal displacement.

Typically, it is considered that the platform must not vary in position under the simple effect of the weight of the skier, also called normal load, and it is observed that the results on the handling of the ski are markedly improved if, under the effect of an impulse corresponding to five or six times the weight of the skier, the platform shifts laterally by one or two millimeters.

Of course, it is not departing from the scope of the invention by multiplying the number of facing cam surfaces, or even by giving them advantageous profiles allowing progression of the offset as a function of the pulse.

Thus, in the variant shown in FIG. 3, the trapezoidal cam surfaces (15, 16) of the platform (10) can be replaced by cylindrical rollers (23, 24) which can optionally be made rotary with respect to their longitudinal axis by means for example of bearings.

The disappearance of the impulse results in the actuation of the return members (12 - 22) which bring the platform back to the initial position, in which its longitudinal plane (25) coincides with the longitudinal plane (6) of the ski. .

Of course, it does not depart from the scope of the invention by integrating the lower plate inside the upper face of the ski, or then by replacing this lower plate with simple trapezoidal cams directly integral with the upper surface of the ski.

Example 2

In a second variant shown in FIGS. 4 and 5 in which only a straight ski is shown, the platform (30) and the lower plate (31) secured to the upper face (3) of the ski are connected by articulated arms (32, 33) inclined to the side of the internal edge (4) of the ski.

These arms (32, 33) are articulated on the platform (30) and on the lower plate (31) by means of axes (34 - 37) parallel to the longitudinal axis of the ski. The inclined arms are articulated either inside housings (38-41) provided for this purpose on the platform (10) and on the lower plate (31), or by means of yokes (not shown) arranged under the platform and on the bottom plate.

Of course, the invention also covers the embodiments in which the lower plate (31) is replaced by simple hinge joints of the arms (32, 33), integral with the upper face of the ski.

As already said, the space between the platform (30) and the lower plate (31) receives a return member (12) formed either of an elastomeric stud, or of a mechanical spring (not shown).

In operation, this device behaves as follows. When the platform (30) is crushed by the force of implusion F, the inclined arms (32, 33) pivot relative to their axis of articulation (34, -37). In this way, the platform moves laterally in the direction of the initial inclination of the arms, namely on the side of the internal edge (4) of the ski.

Example 3

As shown in Figures 6 and 7, in a third embodiment, the offset of the platform (45) relative to the upper face (3) of the ski is provided by at least one elastic metal plate. In the form shown, these two metal plates (46, 47) comprise two horizontal portions (48, 49) respectively integral with the upper face (3) of the ski and with the lower face of the platform (45), connected by a portion inclined (50). The inclination of the inclined portion (50) is directed downward and towards the outer edge (5) of the ski. The blade can be spring steel or aluminum alloy.

Obviously, similar results are obtained by using a larger number of blades arranged in parallel.

In the advantageous form illustrated, the blades (46, 47) are embedded in an elastomeric stud (53) which reinforces the return effect of the blade.

The operation of this intermediate device is as follows.

During the impulse (F) given by the skier, the blades deform at their folding zones (51, 52) and the inclined central part (50) acts as a lever arm causing the shift of the platform (51), as shown in the figure.

Example 4

In the form illustrated in Figures 8 and 9, the platform (85) rests on an elastic wedge (86) which itself rests on a sloping wedge (87) secured to the upper face (3) of the ski. The slope of this wedge is oriented downwards and towards the internal edge (4) of the ski.

Thus, during the crushing caused by the impulse (F) of the skier, the elastic wedge (86), typically made of elastomeric material, deforms and shears in such a way that the platform (85) is offset from the side of the internal edge of the ski, as illustrated in figure 9.

Second operating principle of the invention Example 5

The embodiments shown in Figures 11 and 12 are based on the fact that during a vertical impulse (F) given by the skier, the ski bends downward (see Figure 10). It follows that two fixed points represented in the drawing by the references (55, 56), tend, during bending to approach (57,58).

In FIGS. 11 and 12 showing a portion of a straight ski seen from above, the front being located to the left of the drawing, the platform (60) according to this embodiment, has at least two lights (61, 62) , arranged obliquely to the longitudinal plane (61) of the platform. These two lights (61, 62) are as spaced as possible to use the effect of distance between the fixed points secured to the ski. These lights (61, 62) are oriented in such a way that they converge on the side of the outer edge (5) of the ski.

Inside these two oblique openings, two pins (55, 56) secured to the upper surface (3) of the ski are passed, either directly via yokes, or by means of a lower plate ( not shown).

Furthermore, in an advantageous form, the platform (60) comprises a third lumen (64) arranged transversely, along a bisector of the oblique lumens. This third light also receives a pin (65) or a guide bar secured to the upper face (3) of the ski.

Preferably, the inclination of the lights (61, 62) relative to the median longitudinal plane (6) of the ski is between 30 and 60 degrees, and preferably in the vicinity of 45 degrees.

The operation of this device is as follows.

During the bending of the ski, the fixed points represented by the pins (55, 56) tend to approach. Of course, the platform (60) being undeformable, taking into account in particular the rigidity and the stiffness of the associated shoe, the platform (60) tends to move in order to adapt to the decrease in distance (Do - D) between the fixed points (55, 56). In other words, the approximation of the fixed points (55, 56) tends to drive the platform (60) from the side of the internal edge (4). This movement is of course facilitated and channeled by the transverse groove (64) of complementary guide. As expected, the median longitudinal plane (66) of the platform is offset from that (6) of the ski on the side of the internal edge (4).

Of course, it does not depart from the scope of the invention by reversing the relative position of the pins and the grooves, that is to say by placing the pins under the platform and the grooves on a plate secured to the upper side of the ski. In the same vein, crossing lights have been shown, but it goes without saying that the invention also covers solutions in which the lights are replaced by non-crossing grooves.

Example 6

In the variant illustrated in FIGS. 13 to 15, the platform (70) has two through circular openings (71, 72) located in the extreme parts of the platform (70). These circular openings (71, 72) receive two cylindrical cams (73, 74) with free rotation. Each of these cams (73, 74) comprises a journal (75, 76) arranged eccentrically, extending downward towards the upper surface (3) of the ski to which they are integral. These cylindrical cams (73, 74) are pivotally mounted relative to the pins (75, 76).

In an advantageous form, the cylindrical cams (73, 74) have two bearing surfaces (77, 78) of different diameters, coming to be embedded in two bearing surfaces of complementary diameter arranged in the platform at the level of each opening (71, 72). The bearing surface (77) of greater diameter is disposed on the side of the lower face of the platform (70), this to ensure that this platform (70) is held in place by the cams (71) (see FIG. 14).

To improve the coefficient of friction between on the one hand, the pins (75, 76) and the cams (73, 74), and on the other hand, the cams (73, 74) and the platform (70), the surfaces contact are treated and typically covered with polytetrafluoroethylene.

The operation of this device is as follows. As already said, during the bending of the ski subsequent to a vertical impulse, the fixed points formed by the pins (75, 76) integral with the upper face of the ski tend to approach. This results, at the level of the cams (73, 74), by a rotation of the latter around the pins (75, 76), in order to keep the spacing between the centers (79, 80) of each cam constant. These rotations cause the platform (70) to move and in particular the offset of its median plane (81) relative to that (6) of the ski, as illustrated in FIG. 14.

Third operating principle of the invention

The embodiments described above allow the transverse offset of the longitudinal plane of the binding relative to that of the ski. It is a translational movement which allows the internal edge of the ski to move towards the internal side of the boot. The variants described below, corresponding to a third operating principle of the invention, make it possible to modify the angle formed by the median longitudinal plane of the ski and that of the boot, under the effect of a trigger pulse of turns.

In general, this operation can be obtained by using two platforms (90, 91) as described above, the front platform (90) supporting the stop of the binding while the rear platform (91) receives the heel piece. Thus, each of the two platforms (90, 91) is equipped with means allowing the transverse offset of its longitudinal plane (92, 93) relative to that (6) of the ski. The means may be identical or be of a different nature from one platform to another. In other words, the invention covers devices in which the front platform is for example offset by a cam clearance, while the rear platform operates with the crushing and shearing of an elastic wedge.

In addition, the rotational movement of the orientation of the shoe can be obtained mainly according to two different constructions. Thus, in a first embodiment illustrated in FIG. 18 for a straight ski, the means allowing the transverse offset of each platform cause displacements in opposite directions, namely that the front platform (90) tends to move in the direction of the outer edge (5), while the rear platform (91) shifts towards the inner edge (4). In this way, the ski tends to rotate at an angle greater than that of the boot, which is similar to an oversteering phenomenon.

In another embodiment, illustrated schematically in FIG. 17, the two front (90) and rear (91) platforms tend to offset on the same side, that is to say on the side of the internal edge ( 4), but the offset of the rear platform (91) is greater than that of the front platform (90) which results in the appearance of an angle between the longitudinal plane of the shoe (7) and that (6) ski.

Example 7

The variant embodiment illustrated in FIGS. 19 and 20 follows from the embodiment corresponding to FIGS. 13 to 15. In this particular embodiment, the platform (100) receives in two circular openings (101, 102), two cylindrical cams ( 103, 104) each comprising an eccentric pin (105, 106) secured to the upper face (3) of the ski. To obtain a pivoting of the longitudinal plane (107) of the platform (100) when bringing together the anchor points of the trunnions (105, 106) consecutive to bending of the ski, these trunnions (105, 106) are installed so that the axis (107) connecting them forms an angle with the median longitudinal plane of the ski (6). In this way, when these anchoring points are brought together, the platform (100) naturally tends to position itself in the configuration illustrated in FIG. 20 in which the front (8) of the ski turns towards the inside of the turn , relative to the longitudinal plane (108) of the platform (100).

It appears from the above that the ski according to the invention, that is to say one equipped with the characteristic device makes it possible to offset the ski boot relative to the board when the skier exerts a vertical thrust, in particular when taken turn. This offset may consist of a translation of the boot in a direction perpendicular to the longitudinal plane of the ski, or else in a pivoting of the position of the boot relative to the ski.

It follows that the off-center position of the internal edge improves the speed of tilting from one edge to another, which is particularly sought during the sport of skiing.

In addition, the pivoting resulting in an oversteering phenomenon makes it possible to improve the closure of the turn.

Claims (28)

Downhill skiing : - A lower sliding face, bordered by edges, respectively constituting an outer edge (5) and an inner edge (4), said inner edge corresponding to the two facing edges when the two skis of a pair are placed flat l 'next to each other; - an upper face (3) intended to receive in the skate area an intermediate device consisting of at least one platform (10, 30, 45, 60, 70, 85, 90, 91, 100) on which is mounted a fixing of safety composed of a stop and a heel piece, the median longitudinal plane (25, 66, 81, 108) of the platform being coincident with the median longitudinal plane (6) of the gliding board, when the device supports the weight of the skier, said intermediate device comprising: * means capable of shifting under the effect of a force the position of the median longitudinal plane (25, 66, 81, 108) of the platform relative to the median longitudinal plane (6) of the ski board; * and at least one return member (12, 22) intended, in the absence of said force, to bring the two median longitudinal planes, respectively of the platform and of the gliding board, back to the same position; characterized in that said offset means act under the effect of a force directed perpendicular to the upper face of the gliding board, by causing a lateral offset from the median longitudinal plane of the platform, said lateral offset being an increasing function of said strength. Ski according to claim 1, characterized in that it comprises means for adjusting the threshold for implementing the shifting means. Ski according to claim 1, characterized in that the means capable of modifying the position of the median plane of the platform cause its transverse translation in the direction of the internal edge, under the effect of a crushing force directed towards the face superior of skiing. Ski according to claim 3, characterized in that the means intended to bring about the transverse translation of the platform consist of at least one ramp inclined (17, 18) downwards in the direction of the internal edge (4), in contact with at least one stop (15, 16), each located respectively on the platform (10) and on the upper face (3) of the ski. Ski according to claim 4, characterized in that the stop is constituted by an inclined ramp (15, 16). Ski according to claim 4, characterized in that the stop is constituted by a cylindrical roller (23, 24) whose axis of revolution is parallel to the longitudinal axis of the ski. Ski according to claim 3, characterized in that the means intended to allow the transverse translation of the longitudinal plane of the platform (30) consist of at least two link arms (32, 33) articulated at their upper and lower ends respectively under the platform (30) and on one of the faces of the ski, around axes (34, 37) parallel to the longitudinal axis of the ski. Ski according to claim 3, characterized in that the means intended to allow the transverse translation of the longitudinal plane of the platform (45) consist of at least one elastic blade (46, 47) disposed between the platform (45) and the surface upper (3) of the ski, said blade (46, 47) being oriented towards the lower face of the ski and towards the outer edge (5). Ski according to claim 8, characterized in that the elastic blade is embedded in an elastomeric pad (53). Ski according to claim 3, characterized in that the means intended to allow the transverse translation of the longitudinal plane (66) of the platform (60) consist of at least two guide grooves (61, 62) cooperating with two pins (55 , 56) each arranged on the underside of the platform (60) and on the upper face (3) of the ski, the directions of the grooves (61, 62) converging on the side of the outer edge (5) of the ski. Ski according to claim 10, characterized in that the intermediate device also comprises at least one additional groove (64) of direction parallel to the bisector of the directions of the guide grooves (61, 62). Ski according to claim 10, characterized in that the grooves (61, 62) are arranged on the platform (60) and form through holes. Ski according to claim 10, characterized in that the angle of inclination of the guide grooves (61, 62) relative to the longitudinal plane (66) of the platform is between 30 ° and 60 °, preferably in the vicinity of 45 °. Ski according to claim 1, characterized in that the means capable of modifying the position of the median plane of the platform with respect to the longitudinal plane of the ski are constituted by: - a sloping wedge (87) integral with the upper face (3) of the ski, the slope of said wedge being oriented towards the internal edge (4); - An elastic corner (86) interposed between the sloping wedge (87) and the platform (85). Ski according to claim 3, characterized in that the means intended to allow the transverse translation of the longitudinal plane (81) of the platform (70) consist of a set of at least two pins (75, 76) integral with the face upper (3) of the ski, said pins (75, 76) receiving cylindrical cams (73, 74) able to pivot eccentrically around the pins (75, 76), said cams (73, 74) cooperating with cylindrical housings (71 , 72) complementary formed in the platform, so that the approximation of the pins (75, 76) causes the rotation of the cylindrical cams (73, 74) inside the housings (71, 72), and the lateral displacement of the platform (70). Ski according to one of claims 1 to 9, characterized in that the intermediate device comprises two platforms (90, 91) respectively supporting the stop and the heel of the safety binding. Ski according to claim 16, characterized in that the means allowing the modification of the position of the longitudinal plane (92, 93) of each platform (90, 91) are reversed from one platform to another, so as to obtain a offset of the platforms on either side of the median longitudinal plane (6) of the ski, and to cause the rotation of the longitudinal axis (7) of the boot around an axis perpendicular to the upper face (3) of the ski . Ski according to claim 16, characterized in that the means allowing the modification of the longitudinal position (22, 23) of each platform (90, 91) are in the same direction and cause an offset of different amplitude from a platform to the 'other so as to cause the rotation of the longitudinal axis (7) of the boot about an axis perpendicular to the upper face of the ski. Ski according to claims 16 and 18, characterized in that the means intended to cause the rotation of the platform consist of at least: - A first ramp inclined downward towards the internal edge, in contact with at least a first stop, each located respectively on the first half-platform and on the upper face of the ski; - A second ramp inclined downward towards the outer edge, in contact with at least a second stop, each located respectively on the second half-platform and on the upper face of the ski. Ski according to one of claims 17 and 19, characterized in that the inclinations of the first and second inclined ramps are different. Ski according to claims 7 and 18, characterized in that the arms corresponding to each half-platform are inclined in the opposite direction. Ski according to claims 7 and 18, characterized in that in the rest position, the inclinations of the arms of the half-platforms are different. Ski according to claims 8 and 17, characterized in that one of the blades is oriented towards the underside of the ski and towards the outer edge, and in that the other blade is oriented towards the underside of the ski and towards the edge internal. Ski according to claims 8 and 18, characterized in that in the rest position, the inclinations of the two blades relative to the upper surface of the ski are different. Ski according to claim 1, characterized in that the means intended to allow the transverse rotation of the longitudinal plane (108) of the platform (100) consist of a set of two pins (105, 106) integral with the upper face (3 ) of the ski, the axis (107) passing through the two pins (105, 106) not being parallel to the longitudinal plane (6) of the ski, said pins (105, 106) receiving cylindrical cams (105, 106) able to pivot eccentrically around the pins (105, 106), said cams (103, 104) cooperating with complementary cylindrical housings (101, 102) formed in the platform (100), so that the pins (105, 106) are brought together ) causes the rotation of the cylindrical cams inside the housings, and the displacement of the platform. Ski according to claim 1, characterized in that the means intended to allow the transverse rotation of the longitudinal plane of the platform consist of a set of two journals integral with the upper face of the ski, the axis passing through the two journals being parallel in the longitudinal plane of the ski, said journals receiving cylindrical cams able to pivot eccentrically around the journals, said cams cooperating with complementary cylindrical housings formed in the platform along an axis not parallel to the longitudinal plane of the platform, so that the approximation of the pins causes the rotation of the cylindrical cams inside the housings, and the displacement of the platform. Ski according to one of the preceding claims, characterized in that it has a housing at the level of the skate area, inside which is at least partially embedded the intermediate device. Ski according to one of the preceding claims, characterized in that the means intended to allow the movement of the platform, which are integral with the upper face of the ski, are mounted on a lower plate, itself integral with the ski.

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