WO1999008759A1

WO1999008759A1 - Improved ski equipment

Info

Publication number: WO1999008759A1
Application number: PCT/FR1998/001798
Authority: WO
Inventors: Pascal Didier Toschi
Original assignee: Pascal Didier Toschi
Priority date: 1997-08-13
Filing date: 1998-08-12
Publication date: 1999-02-25
Also published as: FR2767266B1; FR2767266A1

Abstract

The invention concerns an equipment comprising boots (6), skis (1) and fixing elements (2) each designed to be integrated with one boot (6) and its associated ski (1) and to cause them to be separated in the event of a situation which can lead to the skier wearing the equipment to be injured. The invention is characterised in that it further comprises in each boot: first means (9) maintaining the foot medio-tarsal part integral with the boot sole; second means (15) maintaining the part linking the rear of the foot to the leg, while allowing that part to rotate in the boot (6) about an axis substantially oriented along the shin bone axis; sensing means (25) sensitive to a differential rotation between the first and second maintaining means (9, 15); and means for unlocking (28) said fixing element (2) controlled by said sensing means (25) to release said fixing element (2) in the presence of such a differential rotation.

Description

Improved ski equipment The present invention relates to ski equipment comprising mechanisms for controlling the separation of a boot and a ski, in order to avoid injuries to the knee joint during skiing alpine. More specifically, the invention relates to such equipment considerably reducing the risks of rupture of the antero-external cruciate ligament of the knee.

The invention is based on the observation that, despite the excellent functioning of the ski bindings currently in use, it can be seen that, year after year, a sprained knee remains a lesion very frequently suffered by skiers, the number of 'sprains per season which can be between 10 000 and 12 000 in France. This number is considerable if we consider that the bindings are most often regulated by specialists, so that the cause of these lesions cannot be linked to wrong setting. We also know that tearing, or even rupture of the antero-external cruciate ligament of the knee, often requires heavy and traumatic surgery for the patient, not to mention the cost that the community must bear to finance this care, postoperative treatments and often the high cost due to the patient's absence from the workplace. The idea generally accepted in the design of ski bindings consists in considering that the musculature is itself capable of protecting the ligaments of the knee thanks to muscular contractions caused by the skier's reflex. This reflex is conditioned by the unconscious mental mechanism supposed to be instilled in the skier first during the teaching from which he can benefit, then later thanks to his own experience in the field. The reflex being thus stored, it makes it possible to provoke during the practice of the ski an "active stiffness" of the musculature of the body of the skier which becomes thus a uniform mass to which the binding will react when a danger to the conformation of the skier arises. However, the setting of the binding is chosen according to this uniform mass, that is to say practically the weight of the skier, when he is in a state of "muscular alertness" causing this active stiffness.

Most bindings proceed by lateral exhaust from the front of the shoe to the jaw before the binding, if a torque is applied to the shoe exceeding the chosen setting (for example N ° 6 on a scale of 1 to 10) .

The problem underlying the present invention stems from the fact that this usual calibration (which is necessary so that the binding does not drop unexpectedly and too frequently when there is no danger) is far too great to be able to avoid the tear or rupture of the antero-external cruciate ligament which can already give way if the effort undergone exceeds approximately 1700 N, in the absence of muscular alertness. However, such an absence turns out to be frequent on the one hand among experienced skiers in easy situations on the ground and on the other hand among skiers of all levels in a situation close to stopping. Indeed, in such conditions, the skier does not perceive the imminence of a danger and will not anticipate the risk of trauma. It is then that a differential rotation can occur between the tibia and the femur due to a rotary lateral thrust on the ski roughly along the axis of the tibia, differential rotation which can precisely damage or even tear the ligament in question. It should be noted that, as a general rule, female subjects present a higher risk of rupture of the cruciate ligament compared to male subjects, due not only to their anatomical differences (in particular greater flexibility at the knee joint ) but also the difference in mental state, woman who tends to adopt a more relaxed attitude and style of skiing than the man.

The object of the invention is therefore to propose a ski equipment provided with mechanisms making it possible to control the separation of a boot and a ski, in order to avoid injuries to the knee joint during the practice of alpine skiing. , while retaining the ability of the binding to react normally to the stresses for which a binding is conventionally designed. The invention therefore mainly relates to a ski equipment composed of a pair of boots, a pair of skis and a pair of bindings each intended to secure a boot and an associated ski and cause their separation in the presence of a situation likely to lead to injury to the skier wearing this equipment, characterized in that it further comprises in each of said shoes: first holding means arranged in said shoe to maintain the mid-tarsal area of the foot integrally by compared to the sole of this shoe; second holding means for holding the leg-leg portion, while allowing limited rotation of this part in said shoe around an axis oriented substantially along the axis of the tibia; detection means sensitive to differential rotation between said first holding means and said second holding means; and means for unlocking said fastening controlled by said detection means to release said fastening, in the presence of such a differential rotation.

Thanks to these characteristics, each pair of shoe and binding of the equipment can be separated by not only the efforts to which each binding can react in the event of risk of injury in the presence of a muscular vigilance, but also by means of much reduced efforts which risk leading to knee injuries in the absence of muscular vigilance on the part of the skier.

Other characteristics and advantages of the invention will become apparent during the description which follows, given solely by way of example and made with reference to the appended drawings in which: FIG. 1 shows a schematic elevation view in section one of the right or left sets of ski equipment according to the invention; Figure 2 is a schematic elevational view of the shoe shown in Figure 1 to show in particular the first and second holding means as well as the detection means according to the invention, it being understood that this is by way of 'example of the right shoe; Figure 2A is a sectional view taken along the line IIA-IIA of Figure 2; Figure 3 is a rear view of the right shoe, its outer rigid shell being partially removed to show the second holding means and the detection means according to the invention; Figure 4 is a partial view, on a larger scale and in schematic section along a longitudinal vertical plane, of the ski boot as well as the rear part of the binding thereof to the ski; Figures 5 and 6 are views in horizontal section taken respectively along the lines VV and VI-VI of Figure 4; - Figure 7 shows schematically in a side elevation view, how the shoe is secured to the binding, Figure 7A shows in plan view a detail of the binding of Figure 7; Figure 8 is a plan view of the front part of the binding located at the front of the ski boot and the part thereof ensuring, if necessary, the unlocking of this front part; Figure 9 is a longitudinal vertical sectional view of the front part of the binding and that of the ski boot; FIGS. 10A and 11A show views, in diagrammatic horizontal section, of the right shoe just at the ankle, respectively in a normal situation and in a situation where the antero-external cruciate ligament is stressed to the point of risking rupture; FIGS. 10B and 11B show, by similar views, sections of the second holding means above the ankle; Figures 10C and 11C show similar views of the sections of the second holding means at the top of the shoe.

We will first refer to Figure 1 which very schematically illustrates the principle which is the basis of the present invention. The assembly shown is the right or left part of ski equipment and comprises a ski 1, not shown in detail, a binding 2 comprising a mounting plate 3 secured to the ski 1 by any appropriate means and composed of a part front 4 and a rear part 5, and a shoe 6. The front and rear parts 4 and 5 have only been outlined in this figure, it being understood that a preferred embodiment will be described below. It will already be noted at this stage that the rear part 5 is placed below the middle of the boot 6 seen in the longitudinal direction of the ski 1.

The shoe 6 has a classic shape with a rigid outer shell 7 secured to a sole 8.

In FIGS. 2 and 3, it can be seen that in the rigid outer shell 7 are firstly arranged a fixed liner 7a covering the metatarsals and the toes, as well as first holding means 9 formed of a lining 10, made of a semi-rigid material, with a plantar part 11 fixed on the top of the sole 8 and two side flaps 12 intended to partially cover the mid-tarsal part of the foot. Each flap 12 is rounded at the front and ends obliquely at the rear along a line which extends from the tip of the heel to the antero-malleolar region (see in particular Figure 2). A V-shaped cut 13 facilitates the application of the flaps 12 on the foot and improves the detection performance, as will be seen later.

The plantar part 11 extends towards the rear where it is equipped with a hole 14.

The shoe 6 also includes second holding means 15 formed by a sheath 16 intended to wrap the posterior part of the leg-leg assembly. This sheath is made of a semi-rigid material in one piece, for example the same as that of the lining 10. At its base it has a cap 17 enveloping the heel and provided with a substantially flat bottom from which projecting downward a pivoting pin 18 which is engaged in the hole 14 of the semi-rigid lining 10.

The sheath 16 is then extended upwards by a central zone 19 intended to wrap the achilles-hamstring part, while leaving the front of the leg uncovered inside the rigid shell 7.

Anatomically, it can be seen that the cap 17 makes it possible to cover the retro-malleolar grooves up to the myotendinous junction of the triceps, the median zone 19 covering the lateral and rear faces of the calf.

While continuing to wrap the rear face and the lateral faces of the leg, the sheath 16 has an upper zone 20 extending forwards by two flaps 21 intended to be applied one on the other on the in front of wearing shoe 6 and attaching to each other by a fastening strip 22 of the Velcro® type.

As can be seen in Figures 2 and 3, and according to an important characteristic of the invention, the sheath 16 is distant from the internal surface of the rigid shell 7 over its entire extent, only the bottom of the cap 17 being supported on the rear part 11 of the lining 10. As a result, the sleeve 16 has a limited freedom of rotation about the vertical axis of the lug 18. At its upper part, the sleeve 16 is guided in its movement of rotation by a rail 23 with a T-shaped section formed on the internal surface of the rigid shell 7 at the bottom of the upper zone 20. This rail follows, roughly in a horizontal plane, the periphery of this shell 7 over part of its extent. It cooperates with a slide 24 formed by a groove of section complementary to that of the rail and formed by forming with the sleeve 16. This slide follows the outer periphery of the latter by sliding on the rail 23, during the rotational movements of the scabbard. The lining 10 and the sheath 16 are both semi-rigid with an internal lining of the gelled foam type which is molded into the relief of the corresponding parts of the leg and of the foot of the wearer. The material from which these two elements are made may be the "ORFIT" commercially available from 3M.

The ski equipment according to the invention also comprises detection means, generally designated by the reference 25 in FIG. 1 and intended in particular to detect a differential rotation between the lining 10 and the sheath 16.

In the embodiment described and shown, these detection means 25 comprise in each shoe 6 a set of two cables 26 and 27 (Figures 2, 2A and 3). The routing of cables 26 and 27 is carefully chosen in order to allow good detection, in particular of the movement of differential rotation capable of causing damage to the antero-external ligament of the knee.

Each cable 26 or 27 is attached to the front of the shoe laterally with respect to the foot to a control device 28, a detailed description of which will follow (Figure 2).

Attached to the right to the control device 28 in the shoe on the right, the cable 26 first passes through the front of the rigid shell 7, in which a guide channel 29 is formed, then it passes on the left side so that the 'we no longer see it in Figure 2 at least at this point. The cable 27 which comes from the left part of the control device 28 also passes through a channel 29 of the rigid shell 7, then from the right side to become visible in FIG. 2. At the exit of this channel 29, the cable 27 penetrates in a channel 30 formed in the right lateral flap of the lining 10 which is located at the height of the line between the first metatarsal and the first wedge-shaped. The cable 27 passes in an extension of this channel 30 by freely crossing the V-shaped cutout 13. Then, it leaves it at the level of the external malleolus to enter a similar channel 30 formed in the sheath 16.

The cable 27 enters this channel at the height of the retro-malleolar part, and then follows the rear part of the sheath (FIG. 3) starting to the left and crossing the cable 26 just below the slide 24. It ends then in the left flap 21 of the sleeve 16 where a tensioner 31 is located (not visible in the figures).

The cable 26 follows an opposite path, being hooked on the right in the control device 28, passing through the left flap 12 and the sheath 16 then after having crossed the cable 27 behind it, leading to a tensioner 31 located in the flap 21 on the right.

Of course, the same description can be made, mutatis mutandis for the shoe 6 on the left. The right and left turnbuckles 31 are of identical construction. Each of them comprises a box 32 of rectangular vertical section in which are arranged, in opposition on the small faces, two racks 33 cooperating with a locking block 34. This comprises pawls 35 resiliently biased towards the outside and cooperating respectively with the racks 33. The pawls 35 can be retracted into the block 34 by means of a handle 36 accessible from the outside of the locking block 34. When the pawls 35 are out, they oppose the movement of the block 34 in the direction of unlocking or relaxing the corresponding cable 26 or 27 by bracing on the sides of the teeth of the racks 33. Consequently, when the block 34 is pulled by bringing it closer to the end edge of the flap 21 , the pawls jump from a pair of teeth opposite to another pair of teeth of the racks 33 which tightens the corresponding cable without possibility of relaxation.

On the other hand, when the user turns the lever 36, the pawls 35 are retracted so that the block 35 can move in the opposite direction (in FIG. 1 to the left) by causing the corresponding cable to relax.

Thus, after having put on the shoe 6 and positioned the leg and the foot correctly in the sheath 16 and the lining 10, the skier, by actuating the two tensioners 31, can tension the cables 26 and 27, which folds the lining and the sheath on the corresponding anatomical parts to wrap them tightly at the tension desired by the skier. In fact, it turns out that the correct tension in the cables 26 and 27 is obtained, when the skier has the feeling that his anatomical parts introduced into the shoe are comfortably tightened by the lining 10 and the sheath 16.

We will now refer to Figures 4 to 6 to describe in detail the rear part 5 of the fastener 2. It comprises a locking ring 37 embedded in the sole 8 of the shoe 6 and provided with a cavity 38 with a concave bottom and open downwards. In the wall of this cavity 38 are formed two cells 39 diametrically aligned along the longitudinal median axis XX of the shoe 6 (Figures 5 and 6). These cells 39 each define a profiled attachment surface 40.

The rear part 5 also comprises a chassis 41 integrated into the mounting plate 3. On this chassis is mounted a mounting pin 42 having a certain freedom of rotation about its axis Y-Y which is oriented vertically and cuts the axis X-X. At the base of this mounting pin 42 are provided two cams 43 which are integral with it and which are aligned diametrically along the axis X-X, respectively towards the front and towards the rear. Each cam has a concave profile 44.

The spindle 42 has a diametrical slot 45 (FIG. 5) oriented along the axis XX and at the bottom of this slot 45, it is crossed by a tilting axis 46 on which two hooks 47 are oscillatingly mounted. Between the hooks 47, l axis 46 also carries a hairpin spring 48, the branches of which bear on the hooks 47 so as to urge them outwards away from one another (direction of the arrows fl in FIG. 4) by a tilting around a horizontal transverse axis ZZ (FIG. 5) on which the tilting axis 46 is aligned.

The rear part 5 of the attachment 2 also includes an unlocking ring 49 centered on the axis Y-Y and having in section the shape of an inverted U. It is slidably mounted in the chassis 41 in the direction of the Y-Y axis.

A mounting part 50 is fixed flat on the lower part of the chassis 41 below the unlocking ring 49. This part has a central recess in which the pin 42 and the cams 43 are positioned, the latter having a certain freedom of rotational movement around the YY axis.

Two retaining hooks 51 arranged in diametrically opposite positions along the axis XX are slidably mounted in the mounting piece 50. They are biased inward by return springs 52 bearing between a washer 53 of the corresponding hook and the bottom of a notch 54 formed in the mounting part 50. The hooks 51 are normally engaged with a lower flange 55 formed on the locking ring 49, which they are capable of releasing by being pushed outwards by the cams 43. One or more release springs 56 are arranged in the locking ring 49 by bearing on the mounting part 50. A single helical spring can be provided which goes around in the ring or several springs distributed angularly therein (case which is shown schematically in Figure 4).

We will now refer to FIGS. 7 to 9 to describe more particularly the front part 4 of the attachment 2. However, it will be noted with regard to the rear attachment 5, that the latter also comprises a locking lever 57 (FIG. 7) articulated on the chassis 41 around a transverse horizontal axis 58 slightly forward relative to the rear part 5 of the binding. This lever 57 is shown in FIG. 7A which shows that it comprises a flat plate 59 widened approximately to a quarter of its length from its front end, where it has an opening 60. In this opening 60 is engaged l 'assembly shown in detail in Figures 4 to 6 as seen elsewhere in Figure 7. On the edge of the opening 60 are provided two eyelets 61 in which are taken respectively coupling lugs 62 integral with the periphery of the locking ring 49 and aligned along the axis ZZ roughly in the extension of the tilting axis 46 of the hooks 47 (see Figure 6). The front end of the plate 59 is formed around the axis 58 to ensure the articulation of the lever.

At its opposite end, the plate is provided with a thrust plate 63 on which the skier can press, using a ski pole 64 for example, in order to be able to lower the lever 57, when the binding 2 has to be locked.

The front part 4 of the attachment 2 comprises a pivot 65 mounted for rotation in the chassis 41 around a vertical axis R-R. The distance of this axis R-R from the axis Y-Y of the rear part 5 is chosen according to the size of the skier. It may be adjustable by means of adjustment (not shown).

The pivot 65 is in vertical abutment against the chassis 41 by a shoulder 66 forming a vertical stop facing downwards, its lower part being engaged in a hole 67 in the chassis. This lower part has a lateral flat 68 against which resiliently bears a plate 69 in which can turn an adjusting screw 70 of the tension at which the binding must be adjusted to react to dangerous situations in the event of muscular vigilance of the skier.

To this end, a spring 71 is more or less compressed by this screw 70 thanks to a tension plate 72 which is screwed on this screw. This plate can be provided with an indicator finger to allow the display of the force with which the fixing 2 is adjusted, through a window of the chassis 41. In addition, the screw 70 is rotatably mounted therein. The pivot 65 also includes a shoulder 73 forming a vertical stop facing upwards. Against this shoulder abuts a clamping housing 74 which is engaged on the pivot 65 at its front part where it has a hole 75 adjusted to the diameter of the pivot 65 above the shoulder 73. It is stopped on this pivot by a horizontal plate 76 blocked on the latter by a screw 77. This mounting allows the casing to rotate on the pivot 65, under certain conditions only.

As shown in FIG. 8, in top view, the casing has roughly the shape of a coated A, the top of which is mounted on the pivot 65 and the two branches of which cover a front tongue 78 of the shoe 6.

The housing 74 being hollow, it houses part of a transmission mechanism 79 comprising a lever 80 also having a top view in an A shape. This lever is articulated there around a horizontal transverse axis SS by the branch at the top 81 of A which pivots in the side walls of the casing as shown in FIG. 8.

This branch at the top 81 of the lever 80 also carries a hook 82, the active part of which crosses the front wall of the casing 74 through an opening 83 in order to be able to engage in a notch 84 formed laterally in the pivot 65. FIG. 8 shows that the width of the hook 82 is adjusted to that of the notch 84 so that if the hook is released as shown, the pivot 65 and the casing 74 are integral in rotation.

The lever 80 descends obliquely downwards and backwards where its lateral branches end in plates 85 in the form of a parallelogram which are held in complementary openings 86 provided respectively on either side in the lower wall of the housing 74 The plates 85 are biased downwards by respective springs 87 bearing on the inner face of the upper wall of the casing 74. The front part of the shoe 6 is arranged to receive the control device 28 (FIG. 2) which comprises essentially a pallet 88 mounted oscillating in this front part. When viewed from above, this pallet essentially has the shape of an H, the intermediate branch of which forms an oscillation pin 89 of axis TT oriented horizontally and longitudinally and received in rotation in the tongue 78 of the shoe.

The front branches of this pallet 88 each carry a pusher 90 located respectively below the corresponding hole 86 presented by the casing 74. The pushers 90 are urged upwards by respective springs 91. The rear branches of the pallet 88 form an attachment cable 92 and cables 26 and 27 are respectively connected to it. The operation of this equipment is as follows.

It is assumed that the user wants to put on the ski 1. To do this, he puts on each shoe 6, taking care to fit the foot in the lining 10 and the bottom of the leg in the sheath 16. He tightens the sheaths 16 by the top by attaching the fixing strips 22. Then, it proceeds to tightening the cables 26 and 27 using the tensioners 31 until each lining 10 and each sleeve 16 are tightly applied to the corresponding anatomical parts. The tensioners are locked using the levers 36. The two cables 26 and 27 in each shoe 6 being tensioned at their fair value, the corresponding pallet 88 is in its horizontal neutral position.

When the fasteners 2 are open, the hooks 47 are in their retracted position in which they substantially overlap. The locking ring 49 is in its upper position as is the locking lever 57 (Figure 7). The springs 56 are relaxed and the spring 48 is compressed. The skier can now attach skis 1.

The tongue 78 of the shoe 6 is engaged below the casing 74 of the corresponding binding 2 and the cavity 38 is presented above the rear part 5 of the binding. The hooks 51 are engaged in the cavity 38 while the shoe 6 is placed on the wafer 3. The skier operates the lever 57 using his stick 64 to lower the associated locking ring 49, against the action of the springs 56. The hooks 47 are released and tilt outwards under the action of the spring 48 for hooking behind the respective attachment surfaces 40. The fixings are then locked.

The ski equipment according to the invention that has just been described can essentially respond to two types of stress which can prove to be dangerous. The first type includes the stresses to which the fasteners in use currently react. It is essentially the efforts of rotation in the horizontal plane of the boot relative to the ski which risk inducing a twist on the skier's leg, and the tearing forces which are caused above all by a sudden acceleration of the skier's body relative on skis. The bindings mainly react to these efforts by being adjusted for the situation in which muscular alertness is present. In the bindings according to the invention, the rotational stresses are limited by the front part 4, because if the shoe 6 undergoes a rotational force, the casing 74 is pushed to one side or the other in the direction of the applied effort. (Note that, in a conventional manner, the tongue 78 of the shoe 6 is taken laterally in lateral retaining parts of the casing, parts which have been omitted from the drawing for the sake of simplification).

If the force exceeds the threshold set by the adjustment assembly 68 to 72, the front part 4 gives way and the shoe 6 is released laterally at the front. The rotation being made with respect to ski 2, the cams 44 push the hooks 51 outwards, which releases the locking ring 49 pushed by the springs 56. The ring 49 then strikes the profiled edges of the hooks 47 which leave from this makes them attachment surfaces 40 overcoming the force of the spring 48. The rear part 5 releases the shoe 6.

If the stress leads to a tearing force, the attachment surfaces 40 push the hooks 47 inward provided that the stress exceeds a limit prefixed by the tension of the spring 48 and the profile of these surfaces 40. The hooks 47 are then not actuated by the locking ring 49 from which they escape due to their rounded profile which they have in the area of this ring.

We will now examine the behavior of the bindings according to the invention in the presence of stresses present when the skier abandons (most often unconsciously) muscular alertness. For this, reference will be made more particularly to FIGS. 10A to 11C which respectively represent for FIGS. 10A to 10C and for FIGS. 11A to 11C anatomical attitudes in the absence of such stresses and in the presence of these. Furthermore, FIGS. 10A and 11A concern a view taken at the ankle, FIGS. 10B and 11B a view taken above the ankle and FIGS. 10C and 11C a view taken at the flaps 21. The anatomical parts sketched are not described; they are assumed to be correctly interpreted by those skilled in the art. It is clear that the dimensions given in the drawings to the lining 10 and to the sheath 16, and especially those of the linings which pad them internally strongly depend on the anatomy concerned of each individual. By comparing FIGS. 10A to 10C respectively to FIGS. 11A to 11C, it can be seen that the cables 26 and 27 form means for detecting two types of particular movements present when the skier is not in muscular alertness. A first of this type of movement is a differential rotation of the tibia and fibula with respect to the rear part of the foot. This causes a difference in rotation between the lining 10 and the sheath 16 and consequently a traction on one of the cables 26 or 27 and a relaxation of the other of these cables. Pallet 88 is then urged to tilt around the axis TT (Figures 8 and 9). Therefore, the lever 80 is raised against the action of one of the springs 87 and with the help of the other of these springs. The hook 82 leaves the notch 84 and the casing 74 is freed from the pivot 65 to rotate around its axis RR. The shoe 6 thus initiating a rotation around the axis YY, the rear part 5 of the binding 2 is released, thus separating the ski 1 and the shoe 6. The danger of injury to the knee is therefore immediately eliminated. Note that a differential rotation in both directions operates the opening of the binding, Figures 11A to 11C illustrating only one.

The second type of movement to which the fixation reacts in the manner just described consists of a lateral displacement of the talus which can tilt from one side to the other, which reveals the threat of injury Knee. If this occurs, the talus causes lateral pressure in the rear region of the corresponding side flap 12 of the lining 10, thus stretching the cable 26 or 27 which runs there. This also results in the lifting of the pallet 88 and the release first of the front part 4 and then of the rear part 5 in the same manner as described above. The reaction at the level of the lining 10 can be improved in this respect, if the lining is produced with a V cut as shown in FIG. 2 in particular, the talus exerting its lateral thrust especially on the rear part of the flap 12.

Of course, the two types of combined movements can occur in isolation or simultaneously, the release of the binding being carried out in all cases.

To remove the skis voluntarily, the skier can open the bindings simply by consciously carrying out one or the other of the types of movements which have just been described.

Such an opening can be done without any danger and the command is acquired very quickly by the skier.

Other advantages of the equipment according to the invention are as follows. 1) - The rear part 5 admits a limited recoil or even the release of the boot 6 relative to the ski 1, thus obviating the injuries linked to the hyperextension of the knee.

2) - The release of the rotating foot is made optimal by eliminating the anteroposterior compressive force on the shoe 6.

3) - As already indicated, the binding 2 reacts to the tearing off, when the skier projects himself forward relative to the ski 1.

4) - The binding according to the invention offers perfect resistance to the lateral shear forces applied between the sole 8 and the ski 1.

(5) The usual adjustment of the rear (stop) part of the binding is deleted.

In the specific embodiment of the invention that has just been described, the detection means are formed by cables acting on the front part of the binding.

However, several variants can be envisaged for these detection means and their way of releasing the fixation.

Thus, the cables can be replaced by linkages.

Cables or linkages can be designed to control the rear part of the fastener instead of the front part. The detection can be done by means of mediotarsal lateral plates transmitting the lateral thrust of the foot.

The transmission of the reactions on the lining 10 and the sheath 16 can be done by electrical contactors and the control means comprise electromagnetic devices for actuating the opening of the binding.

Likewise, the electrical means thus arranged can be replaced by hydraulic means.

In another variant, the detection signal can be transmitted from the rear part to the front part of the binding, for example electrically or hydraulically.

Claims

CLAIMS 1.- Ski equipment composed of a pair of boots (6), a pair of skis (1) and a pair of bindings (2) each intended to secure a boot (6) and an associated ski (1) and to cause their separation in the presence of a situation likely to lead to injury to the skier wearing this equipment, characterized in that it further comprises in each of said shoes (6): first holding means (9) arranged in said shoe (6) to hold the mid-tarsal part of the foot integrally relative to the sole (8) thereof; second holding means (15) for holding the leg-leg portion of the skier's leg, while allowing limited rotation of this part in said shoe (6) about an axis oriented substantially along the axis of the tibia; detection means (25) sensitive to differential rotation between said first holding means (9) and said second holding means (15); and unlocking means (28) of said attachment (2) controlled by said detection means (25) to release said attachment (2), in the presence of such differential rotation.

2.- Equipment according to claim 1, characterized in that said first holding means (9) comprise a lining (10) fixed internally to the sole (8) of the shoe (6) and comprising a lower part (11) on which rests the foot and from which laterally flaps (12) intended to wrap the mid-tarsal part of the foot from above and associated with means for clamping this mid-tarsal part.

3.- Equipment according to any one of claims 1 and 2, characterized in that said second holding means (15) comprise a sheath (16) disposed in the rear part of the shoe (6) and extending upwards therein, said sheath (16) being released from the interior wall of said shoe ( 6) to allow its pivoting, and having an extent making it possible to cover the lower leg with the exception of the front part thereof, and in that it is provided at its upper part (20) with means ( 21) to be able to belt the leg in a removable manner. 4.- Equipment according to claims 2 and 3, characterized in that said detection means (25) comprise two traction cables (26, 27) attached by one end to said unlocking means (28) and respectively led laterally towards the back and up along said lining (10) and said sheath (16) to, by a modification of their tension, detect said differential rotation and in that their opposite end located at the top of said sheath (16), is attached to a tensioning mechanism. (31). 5.- Equipment according to claim 4, characterized in that said cables (26, 27) are arranged to also cause the tightening of said lining (10).

6.- Equipment any one of claims 4 and 5, characterized in that said cables (26, 27) cross a first time at the upper part of said lining (10) and a second time at the upper rear part of said scabbard (16).

1. - Equipment according to claim 6, characterized in that said lining (10) laterally comprises rear parts extending said flaps

(12) in the direction of said sheath (16), and in that said cables (26, 27) are attached to these rear parts in order to be able to transmit pressure towards them towards the outside induced by the talus of the skier and thus causing the release of the binding (2) in the presence of such pressure.

8.- Equipment according to any one of claims 1 to 7, characterized in that said unlocking means (28) are located in the front part of said shoe (6) and arranged to unlock the front part (4) of said fixing (2).

9.- Equipment according to any one of claims 1 to 8, characterized in that the rear part (5) of said binding (2) is located below the central part of the sole (8) of the shoe ( 6) and in that it comprises locking means (47) capable of hanging on hooking surfaces (40) of said shoe, locking means which are arranged to unhook from said hooking surfaces (40 ) by pivoting said shoe (6) about a vertical axis.

10.- Equipment according to claim 9, characterized in that said rear part (5) comprises two opposing hooks (47) mounted articulated about a transverse horizontal axis (46) in a frame (41) of said fixing (2) and capable of catching on said hooking surfaces (40) under the action of an elastic force, in that said catching surfaces (40) are provided in notches (39) trapping said hooks laterally in their hooking position, and in that said hooks (47) are mounted articulated about said axis (46) in a support (42) pivotally mounted about a vertical axis (YY) in said chassis (41). 11.- Equipment according to claim 10, characterized in that said pivoting support (42) is coupled to unlocking means (49, 51) capable of driving said hooks (47) from said notches (39) when a torque around said vertical axis (YY) is exerted by said shoe (6) on said hooks (47).