EP0750522A1

EP0750522A1 - Toe piece for a downhill ski safety binding

Info

Publication number: EP0750522A1
Application number: EP95914385A
Authority: EP
Inventors: Frédéric Paradis
Original assignee: Look Fixations SA
Current assignee: Look Fixations SA
Priority date: 1994-03-24
Filing date: 1995-03-20
Publication date: 1997-01-02
Anticipated expiration: 2015-03-20
Also published as: WO1995025567A1; US5899484A; FR2717705B1; DE69503770D1; EP0750522B1; ATE168897T1; DE69503770T2; FR2717705A1

Abstract

PCT No. PCT/FR95/00338 Sec. 371 Date Sep. 24, 1996 Sec. 102(e) Date Sep. 24, 1996 PCT Filed Mar. 20, 1995 PCT Pub. No. WO95/25567 PCT Pub. Date Sep. 28, 1995A toe piece for a ski safety binding includes a jaw having two lateral arms. The lateral arms pivot about a pin. The return and holding forces during the elastic travel are proportional to the triggering threshold. The useful elastic travel is independent of the triggering threshold. A lateral arm of a jaw exerts a moment on a lever which pivots. The lever is connected at one end to a spring. The triggering threshold is adjusted by altering the ratio of the distances between, on the one hand, the pivot of the lever and the point of contact between the spring and the lever and, on the other hand, the pivot of the lever and the point of contact between the jaw and the lever. The jaw acts on the lever through a movable part which is moved to adjust the triggering threshold.

Description

FRONT STOP FOR ALPINE SKI SECURITY FIXING

The invention relates to a front stop for alpine ski safety binding. On a ski, such a stop has the function of holding the front end of a ski boot in place, while allowing this end to be released when the stress exerted on the stop exceeds a predetermined value. This predetermined value is called the trigger threshold. It is chosen so that the force that holds the boot is below the force required to break the bones or tear the ligaments of the skier who boots the ski. The lateral force retaining the shoe designates the force perpendicular to the axis of the shoe exerted at the extreme front end of the shoe corresponding to the torque that the skier must exert to rotate it around an axis located near its tibia.

On the known ski binding front stops, the skier's boot is held in a jaw comprising two lateral wings. Each side wing pivots about a vertical axis. It is returned to its rest position by a spring. The shoe can be released from the binding when the jaw pivots by a certain angle around the axis, corresponding to a certain elastic stroke. The elastic stroke designates the distance that the front end of the shoe travels before being released. Each angular position corresponds to a return force exerted by the spring: it is equal to the spring constant multiplied by the compression or total extension of said spring.

During the lateral run, the force holding the shoe depends on the following five factors:

- the increasing force of the spring (s);

- the decreasing lever arm of the lateral wing acting on one of the two rounded ends of the front of the shoe around the pivot axis, the tibia; - an increasing component of the longitudinal thrust of the heel which presses the shoe against the front stop, which reduces the retaining force;

- the specific internal mechanism of the front stop;

- increasing friction. In general, the result is that the force retaining the shoe increases from the rest position, reaching a maximum or threshold trigger after part of the total stroke. This part varies depending on the threshold setting.

The elastic stroke consists in fact of a useful first part where effectively the return force of the spring can overcome the friction forces plus a component of the longitudinal thrust of the heel piece, and recalls the shoe in the rest position, and a second part where the result of these forces combined with the decreasing lever arm act on the rounded tip of the front of the shoe around the shin, no longer recalls the shoe which therefore remains immobilized in the eccentric position, if no additional external force is not exercised, either to release it or to refocus it.

It is known to be able to adjust the triggering threshold on stops of ski bindings. Indeed, this threshold is not the same for all skiers. It varies according to the size and weight of the skier, as well as his level.

It is possible to adjust the trigger threshold by varying the return force exerted by the spring. The solution adopted is generally that of compressing or tensioning the return spring more or less when the jaw is in its rest position. The more the spring is compressed or stretched in this rest position, the higher the trigger threshold.

With such attachments, the force for returning the jaw to its rest position, for positions below the release position, depends on the setting of the triggering threshold. When the trigger threshold is set close to the minimum, the return spring is not very compressed in the rest position. Therefore, in the vicinity of this position, the holding force is low, compared to the force of the triggering threshold. This balance of forces is designated by the term holding the shoe, and this low holding results for the skier by a feeling of lack of firmness at the start of the elastic race.

When the trigger threshold is set to an intermediate value or to the maximum, the return spring is much more prestressed when the jaw is in the rest position and the retaining force in the vicinity of this position is closer to the force of the threshold. trigger. It is also noted with such bindings that the closer the trigger threshold is set to the minimum, the more proportionally the component of the axial force coming from the heel piece and the friction generated. Therefore, the first useful part of the elastic stroke, ensuring a return to the rest position as described above, is very reduced, and the second part, where the shoe remains immobilized in the eccentric position, is greatly increased , compared to a threshold setting closer to the maximum.

Preferably, the retaining force is constant, from the rest position, to the position of release of the boot from the binding. Constant strength has two advantages.

First, it gives the skier a better shoe hold.

Second, the energy absorption by the spring is maximum for a given trigger threshold setting.

The object of the invention is to provide a front stop for ski safety binding comprising a jaw having two lateral wings, pivoting around at least one axis, such as the restoring and restraining forces during the elastic stroke are proportional to the triggering threshold, the useful elastic stroke then being independent of this threshold.

To this end, the front fixing stop it offers is a front stop for alpine ski safety fixing comprising a body, a jaw comprising two lateral wings, pivotally mounted around at least one substantially vertical axis, and a lever. mounted pivoting about a transverse axis integral with the body and on which the jaw, or a jaw wing, by pivoting around its axis exerts a torque, characterized in that the lever is connected to the end of at least one spring, the other end of which is articulated at a fixed point on the fixing body, the setting of the triggering threshold being effected by modifying the ratio of the distances between, on the one hand, the axis of the lever and the point of application of the spring return force on the lever and, on the other hand, the axis of the lever and the point of application of the force exerted by the jaw on the lever, acting on a moving part. When a ski boot, fitting the binding, exerts an action on a lateral wing of the jaw, a torque is exerted on the the sink. This torque is then opposed by a resisting torque exerted by the spring. By modifying the distance between the axis of the lever and the point of application of the spring return force on the lever, the resistive torque opposing the rotation of the lever is changed. The torque exerted by the jaw on the lever, and therefore also the force exerted on the jaw, necessary to remove the binding varies. The trigger threshold is therefore modified. Equivalently, this triggering threshold is modified by varying the distance between the axis of the lever and the point of application of the force exerted by the jaw on the lever. Thus, without having to modify the spring preload when the jaw is in the rest position, it is possible to modify the triggering threshold.

A first variant is characterized in that the lever is mounted vertically in the longitudinal direction of the ski and pivots about a transverse axis passing through the lever, in that the jaw or each lateral wing of the jaw acts by means of a connecting piece on the lever at an application point situated on one side of the transverse axis, in that at least one spring is articulated by its ends, on the one hand, on the fixing body and, on the other hand, on a threaded part, slidably mounted on the lever on the other side of the transverse axis, capable of sliding perpendicular to the transverse axis and in that a screw, mounted on the lever and engaged in the sliding part, moves the latter by turning.

A second variant is characterized in that the lever is mounted vertically in the longitudinal direction of the ski and pivots about a transverse axis passing through the lever, in that the jaw or each lateral wing of the jaw acts by means of a connecting piece on the lever at an application point located on one side of the transverse axis, in that at least one leaf spring is articulated by its ends on the one hand on the fixing body and d on the other hand on a movable part which, displaceable perpendicular to the transverse axis, is provided with a rack cooperating with a rack integral with the lever, locking means being provided to maintain the movable part in position vis-à-vis - screw of the lever. In this case, the spring is a leaf spring which tends to buckle when subjected to stress. To reach buckling of such a spring, a force of intensity greater than a critical value must be exerted (Euler force). Once this threshold is exceeded, the blade behaves substantially like a conventional spring of relatively low stiffness but highly prestressed. Thus, the lateral wing of the jaw, must exert on the spring by means of the lever, a force greater than or equal to the critical force, to pivot around its axis. Once the critical force is reached, the stiffness of the spring leaf being relatively low, the return force of the spring increases little, but the lever arm of the spring with respect to the axis of the lever increases enough to counteract the tending factors. to reduce the force which retains the shoe during the elastic stroke, in particular the increasing component of the axial force of the heel piece and the reduction of the lever arm of the lateral wing acting on the shoe. In this second variant, the locking means ensuring the holding in position of the movable part with respect to the lever may comprise, for example, a wedge secured to a removable flap, mounted on the fixing body possibly forming a window , cooperating with a lug secured to the lever or with at least one lateral wing, or else these locking means may comprise a tongue secured to the moving part, and having at least one tooth cooperating with a second rack secured to the lever.

The springs used in these variants are preferably spring leaves of composite material with fibers mainly unidirectional in the longitudinal direction, with fibers possibly crossed at approximately 90 ° near the neutral axis.

The shape of these spring blades is suitable for this application, if they are of constant thickness, except at the ends where they are rounded, forming an arc of a circle whose center is offset with respect to the neutral axis of the blade, and if these blades are wider in the center than at the ends, so that in maximum flexion each blade is deformed according to an arc of a circle, that is to say has a constant radius of curvature. The eccentrically rounded ends favor buckling in the chosen direction. These blades can be stacked in parallel to increase their strength. One can also provide a damping device substantially parallel to the spring (s), so that the force opposing the movement of the jaw, and therefore the triggering threshold, are a function of the speed of said movement of the jaw.

Another variant of this ski binding is characterized in that the lever comprises two parallel flat plates in the shape of an "L", which are placed vertically in the longitudinal direction of the ski and spaced from each other, and a plate plane connecting two branches of the two L-shaped plates and perpendicular to them, in that the lever pivots about a transverse axis passing through the end of the connected branches of the L-shaped plates, in that the spring is a helical spring articulated at one of its ends at a fixed point of the fixing body and by its other end at the ends of the non-connected branches of the L-shaped plates, in that a sliding part which can be move while approaching or moving away from the axis around which the lever pivots is guided on the flat plate connecting the two plates in the shape of "L" and in that the jaw, or each wing of the jaw acts on the lever through d 'A connecting bar articulated on the one hand on the jaw, or a wing of the jaw, and on the other hand on the sliding part. By moving the sliding part, placed between the jaw and the lever, the position of the point of application of the force exerted by the jaw on the lever is changed, while the position of the point of application of the spring return force remains unchanged. This therefore sets the value of the trigger threshold. The displacement of this sliding part can be obtained by various devices. For example, it may be a device where the adjustment of the position of the sliding part on the flat plate connecting the two plates in the shape of an "L" is carried out using cables which connect the sliding part to a nut which can move thanks to a screw mounted on the fixing body and which are guided by pulleys, the axis of one of these pulleys being coincident with the axis of the lever. In another example, the sliding part is tapped and a threaded rod at one end and provided with a toothing at its other end is, on the one hand, engaged in the sliding part, and, on the other hand, rotated through its teeth by a rack. A fourth variant, fairly close to the previous variant, is characterized in that the lever comprises two parallel flat plates connected to each other, which are placed vertically in the longitudinal direction of the ski and spaced from each other, in that the lever pivots around a transverse axis passing through the two parallel flat plates of the lever near the center of these, in that a sliding part which can move in approaching or moving away from the axis around which pivots the lever is guided between the two flat plates and is connected to the jaw, or to each wing of the jaw, by means of a connecting piece, in that the spring, one end of which is articulated at a fixed point of the fixing body is a helical spring whose other end is articulated at one end of each flat plate of the lever, in that at the other end of the lever, between the flat plates, is mounted on a n axis, a lever movable in rotation, one arm of which is in contact with a screw mounted in the first lever and which comes, via another arm, in abutment against the sliding part, in order to be able to slide this last on the edges of the flat plates.

In these last two variants, where the spring is a helical spring, it is preferable that this is fitted onto or in a tube, in order to ensure good guidance of the spring, which is otherwise only held by its two ends. .

Advantageously, the tube and the articulated connection on the body of the binding form a single piece. One can also provide a damping device with a substantially cylindrical cylinder which, on the one hand, would ensure the stability of the spring or springs, and, on the other hand, would provide damping whose force adjustment would be automatically aligned with the adjustment elastic force, and therefore trigger threshold, without any additional device. This damping device may include a fluid damper mounted in parallel with the spring, between a fixed point of the fixing body and the lever.

In the case where the spring mounted between the fixing body and the lever is a helical spring, it is advantageously fitted onto the fluid damper which serves as a guide. When the jaw has two axes around which the lateral wings pivot, these preferably converge slightly towards each other upwards, giving a diagonal trajectory, slightly from bottom to top, of the lateral wings. Thus, during a rear fall combined with a twist around the skier's leg, the vertical force component exerted upward on the jaw creates a torque relative to the axis of articulation of the wing. lateral, reducing the lateral force necessary to trigger the fixation.

It is also advantageous to tilt the vertical retention plane of the lateral wings in order to further increase said torque created by a vertical force upwards, in order to be able to release the shoe under the effect of a purely vertical force. associated with a rear fall without torsion.

To allow the best return of the boot in the axis of the ski, an anti-friction plate, in polytetrafluoroethylene for example, is fixed on the binding of the ski, in front of the jaw, at the place where rests a boot held in the binding .

In a preferred alternative embodiment, the front stop according to the invention comprises a second lever mounted pivoting about an axis substantially parallel to the transverse axis of the first lever, a first end of this lever being intended to be placed under the 'front end of a shoe for a skier and the second end of this lever being intended to be housed in a notch made in the first lever.

Thus, during a front fall combined with a twist around a tibia of a skier, the second lever creates a torque on the first lever tending to release the boot placed in the stop to compensate for the frictional forces due to the fall before which appear and oppose the release of the skier's shoe.

In any case, the invention will be clearly understood with the aid of the description which follows, with reference to the appended schematic drawing, representing by way of nonlimiting example embodiments of this front stop. ski binding.

Figures 1 to 4 show a first embodiment of this stop,

FIG. 1 is a view of it in longitudinal section along line ll of FIG. 2, FIG. 2 is a top view of it, the jaw of the ski binding being in the rest position Figure 3 is a top view, the jaw being in the release position,

FIG. 4 is a view in longitudinal section of the stop, along the line I V-1 V of FIG. 3, FIG. 5 is a view in longitudinal section of a second embodiment of this stop,

Figure 6 is a side view of the spring used in the two previous embodiments,

Figures 7 to 1 1 show a third embodiment of this stop,

Figure 7 is a top view, the jaw being in the rest position,

FIG. 8 is a view in longitudinal section thereof, along the line VIII-VIII of FIG. 7, the triggering threshold being set to the maximum, FIG. 9 is a top view of this stop, the jaw being in the release position,

FIG. 10 is a view in longitudinal section of this stop along the line X-X of FIG. 9,

FIG. 11 is a view in longitudinal section of this stop, according to line VIII-VIII of FIG. 7, the triggering threshold being set to the minimum,

FIG. 1 2 is a view in longitudinal section along the line XII-XII of FIG. 13 of a fourth embodiment of this stop,

FIG. 13 is a top view of this fourth embodiment of the stop according to the invention,

FIG. 14 and FIG. 1 5 show a fifth alternative embodiment of this stop, in longitudinal section, the jaw being respectively in the rest position and in the release position,

FIG. 16 is a front view of a front ski binding stop according to the invention,

Figure 1 7 and Figure 18 show a sixth alternative embodiment of this stop, in longitudinal section, the jaw being respectively in the rest position and in the release position.

Figures 1 to 4 show a first embodiment of a ski binding according to the invention. A fixing body 1 serves as a support for two lateral wings 2, 3, each pivotally mounted around of a vertical axis 4 and forming a jaw. The binding by means of the jaw 2,3 is intended to maintain the front end of a ski boot 5 in the longitudinal axis of the ski, but also to allow the boot 5 to be released when a force, corresponding to a moment substantially around the tibia, exceeding a predetermined limit, called the triggering threshold, is reached or exceeded. When sufficient force is exerted on the jaw 2, 3 by the shoe 5, a side wing 2 or 3 of the jaw pivots about its vertical axis 4 leaving its rest position (Figures 1 and 2) towards its release position (Figures 3 and 4).

When a force is exerted on a lateral wing, this is transmitted to a lever 6, movable around a transverse axis 7, by means of a connecting piece 8. This force creates a torque with respect to to the axis 7 to which a resistive torque is opposed, generated by the action of two springs 9.

One end of each of these springs is articulated in a suitable cavity in the internal wall of the ski binding body. The other end is articulated on a movable part with adjustable position 10. This part is slidably mounted on the lever 6 by means of a slide link and is tapped. A screw 1 1, movable in rotation, immobile in translation, relative to the lever 6, is engaged with the movable part 10. When the jaw 2, 3 is in the rest position, the screw 1 1 is substantially vertical. The moving part 10 can therefore move from bottom to top or vice versa, bringing with it the end of the springs 9. It is thus possible to vary the resistive torque exerted by the springs 9 on the lever 6, and therefore the threshold of trigger.

The moving part 10 also serves as a cursor and has an index 54 which indicates the setting of the triggering threshold chosen on a scale on the lever 6, through a light 55 on the lever and a window on the rear wall of the body 1 of the binding .

These springs are spring leaves. Figure 2 shows these springs in top view: they are wider in the center than at the ends. Figure 6 shows them from the side: they are of constant thickness except at the ends which are rounded eccentrically with respect to the neutral fiber, in this case in a quarter circle, of radius substantially equal to the thickness of the blade. These springs are made of composite material with fibers mainly unidirectional in the longitudinal direction and fibers crossed at 90 ° near the neutral axis. The two blades are mounted side by side and are wider in the center. Optionally, these blades could be integral and be joined in their center in one piece.

The springs 9 being spring blades stressed in compression in the longitudinal direction, there is deformation of these blades, and therefore consequently rotation of the lever 6 around the axis 7, only when the force exerted on the ends exceeds a value, called the Euler critical force, beyond which the blade 9 flames. The leaf spring then curves and behaves substantially like a conventional spring having a relatively low stiffness, and a significant prestress.

In order to limit friction, an anti-friction plate 12 is placed under the ski boot 5. A variant of this stop is shown in FIG. 5. Here, the mode of adjustment of the triggering threshold and its display vary. In addition, the two connecting pieces 8 are integral and no longer form a single connecting piece 8. The movable piece with adjustable position 10 is no longer tapped, but provided with a rack 53, cooperating with a first rack 1 3 linked to the lever 6. A tongue 14, provided with a tooth 1 5 is secured to this movable part 10. This tooth cooperates with a second rack 1 6, also linked to the lever 6.

In this variant, when the attachment is paved, the spacing of the lateral wings 2,3 induces an opposite force of the springs 9, which push and lock the rack 53 of the moving part 10 relative to the rack 13 linked to the lever 6. When the binding is removed, in order to prevent said racks from coming off and the setting to be modified, two locking means are provided:

- The first means comprises a wedge 1 8 associated with a window 19 which blocks the rotation of the lever 6 in the direction of clockwise, and is placed directly between the body 1 and the lug 17 of the ievier 6. This wedge 1 8 could also be located between the body 1 and a side wing 2 (or 3).

Thus, in order to adjust the triggering threshold, it is necessary, with the binding removed, to remove the shim 18 and the window 19 for example by pivoting the assembly around a joint on the body 1. So he is possible to rotate lever 6 clockwise. This movement releases the rack 53 from the movable part with adjustable position 10. Using the tongue 14, it is possible to slide the movable part with adjustable position 10 to the desired position, corresponding to the desired triggering threshold. . The position of the lever 6 is finally blocked in a clockwise direction, by returning the shim 18 and the window 1 9 to its initial position, ensuring the locking of the chosen setting.

- The second locking means always includes the tooth 1 5, which cooperates with a second rack 1 6, also linked to the lever 6. To change the setting, it is necessary, as before, to disengage the main rack 13 from that of the moving part 10 by pivoting the lever 6 clockwise, while pushing to release the tooth 1 5 from the second rack 1 6, and slide the moving part 10 to the desired position.

Advantageously, a small spring integrated into the movable part 10 ensures the release of its rack 53 and the rack 13 of the lever 6. To facilitate adjustment in the direction of increasing the triggering threshold, a small projection 56 is provided. on at least one side of the top of the lever 6, which serves as a pivot / stop actuated by finger or with the aid of any other suitable tool, making it possible to push the tongue 14 in the opposite direction to the push of the lever 6 necessary to release the racks.

The window 1 9 makes the opening in the fixing body 1 more airtight, and makes it possible to view the setting of the triggering threshold indicated by the tooth 1 5 at the top of the tongue 14, serving as an index against the scale, on the top of the lever 6.

In the variant shown in Figures 1 7 and 18, the leaf spring 9 is placed above the axis 7, unlike the two previous variants. The lateral wings 2, 3 are placed below this axis 7.

A compensating lever 70, pivotally mounted about an axis 76 substantially parallel to the transverse axis 7, is provided in this variant. One end 77 of this lever 70 carries the anti-friction plate 12. The other end 78 of the lever is housed in a notch 71 produced in the lever 6. During a front fall combined with a twist around the skier's tibia, a vertical force is exerted on the anti-friction plate 1 2 and also on the end 77 of the lever. This additional vertical force is added to the weight, in part, of the skier and the friction force opposing the lateral movement of the boot is increased, compared to a simple twist around the tibia of the skier. This friction force is opposed to the action of the shoe on one or the other of the lateral wings 2,3 of the stop and therefore to the release of this shoe. The lever 70 is provided to compensate for this additional friction force, that is to say that it makes it possible to promote the release of the shoe when the latter pressed, substantially vertically, on the anti-friction plate 1 2. indeed, by pressing on the end 77 of the lever, the other end 78 of the lever acts on the lever 6, against the leaf of the spring 9. The torque thus created makes it possible to reduce the force necessary to exert on one lateral wings 2,3 to release the skier's shoe.

The ratio of the lever arms around the axis 76, the shape of the notch 71 produced in the lever 6 are chosen so that the torque exerted on the lever 6 by the end 78 of the lever 70 is substantially equal to the loss of torque exerted by a lateral wing 2 or 3 on the lever 6 due to the additional friction force between the anti-friction plate 12 and the skier's shoe.

Figure 1 8 shows the stop according to the variant described above in its shoe release position, at the end of triggering.

In the embodiment, shown in Figures 7 to 1 1, the leaf spring 9 is replaced by a helical spring 109. The parts of this variant having the same function as the corresponding parts of the first two variants have the same references increased by 100.

Here we find the fixing body 101 serving as a support for two lateral wings 102, 103 each pivoting about a vertical axis 104 and forming a jaw, maintaining the front end of the sole of a shoe 105. When the latter exerts a force on the jaw, the latter is transmitted to a lever 106 movable around a horizontal axis 107 by means of a connecting piece 108.

The lever 106 has two parallel plates 120 and 12 in the shape of an "L", placed vertically in the longitudinal direction and spaced from one another. When the jaw 102, 103 is in the rest position, the substantially horizontal branch of the "L" and higher than the other branch. A third substantially flat and vertical plate 1 22 connects the two substantially vertical branches of the plates 1 20 and 1 21 in the shape of an "L" when the jaw is in the rest position. The lever 106 pivots about the axis 107, which passes through the plates in the shape of an "L" near the lower end of the vertical branch, when the jaw is in the rest position.

In the vicinity of the end of the other branch, the end of a cylindrical compression spring 109 is attached by means of an articulated connection. The other end of the spring is fixed by means of another articulated link at a fixed point of the fixing body. When the binding is removed, the end of the spring 109 attached to the lever 106 rests on a surface 142 provided for this purpose on the internal face of the binding body 101. This surface constitutes the edge of a rib 143 of the fixing body 101.

The jaw 102 or 103 transmitting the force exerted by the shoe 105 on a lateral wing, the connecting piece 108 is supported, on the one hand, in a cavity formed in a lateral wing and, on the other hand, in an articular cavity on a movable part with adjustable position 1 10. This movable part 1 10 is guided by a slide link on the plate 1 22 connecting the two plates in the form of "L" 1 20 and 1 21 of the lever 106. In the rest position, the moving part 1 10 can move on a line of greatest slope of the plate 1 22. Thus, for a given force exerted on the jaw, the force transmitted by the connecting part 108 on the lever does not vary, but the torque exerted with respect to the horizontal axis 107 varies as a function of the position of the moving part 1 10.

The position of the moving part 1 10 is adjusted on the plate 1 22 using a screw 123, a nut 1 24, cables 1 25 and pulleys 126. The screw 1 23 is fixed to the fixing body 101, mobile in rotation and immobile in translation relative to this body 101. The nut 124 is engaged on the screw 1 23 and is movable in translation and immobile in rotation relative to the body 101. The cables 1 25 are attached to each side of the nut 104 on the one hand, and to the moving part 1 10 on the other hand. They are guided by the pulleys 1 26. A pulley 1 26 is located at each end of the horizontal axis 107 around which the lever 106 pivots, as well as near the anterior wall of the fixing body 101. Thus, when the lever pivots, the position of the moving part 1 10 does not vary relative to the plate 1 22 without acting on the screw 1 23. The nut 1 24 also serves as a cursor, indicating the adjustment of the triggering threshold on a scale (not shown) fixed on the body 101. Thus, in Figures 7 to 10, the movable part 1 10 is at the bottom when the jaw is in the rest position. This corresponds to the maximum trigger threshold. In Figure 1 1, the moving part 1 10 is at the top, the trigger threshold is minimal.

Figures 12 and 1 3 show a variant of this embodiment. We find the general shape of the previous ski binding stop. Only vary the mode of adjustment of the position of the moving part 1 10 on the plate 1 22 of the lever 106 and the device for viewing the adjustment.

Here, the moving part 1 10 is tapped. It is screwed onto two threaded rods 1 27, each provided at their lower end, with a toothed wheel 1 28. A transfer pinion 1 29 connects the two toothed wheels 128. A lever 130, provided with a rack 1 31, cooperates with the toothed wheels to move the moving part 1 10. A spring 1 32 keeps the rack apart from the toothed wheels 1 28. By pushing the lever 130 so as to rotate it around the fulcrum 133, the teeth of the rack 131 meshes with a toothed wheel 1 28. If the lever 1 30 then moves longitudinally, that is to say by entering or leaving the fixing body, the toothed wheel 1 28 gears turns and by means of the transfer pinion 1 29 drives the other toothed wheel 1 28. The two threaded rods 127 then rotate in the same direction and drive the moving part 1 10. By releasing the lever 1 30, once the desired position is reached, the spring 1 32 keeps the rack away 131 of the toothed wheel 1 28, and recalls the rack 131 in the fixing body 101.

A small lever 134 mounted pivoting about a horizontal axis rests on the upper face of the moving part 1 10 and with an index 135 indicates the setting of the triggering threshold chosen on a scale 136.

Another variant is shown in Figures 14 and 1 5. A lever 206 comprises two parallel flat plates 220 and 221 connected together by a plate 222 substantially horizontal when the lateral wings 202, 203 forming the jaw are in the rest position. The two parallel flat plates 220 and 221 are placed vertically in the longitudinal direction of the ski and are crossed by a transverse axis 207 around which they pivot. The plate 222 is tapped and receives a screw 237. The head of the screw 237 is provided with a slider 256 free in rotation, the index of which indicates the setting of the triggering threshold on a scale 257 fixed on the lever 206. A sliding part, with adjustable position 210 is guided on the edges of the vertical plates 220 and 221. It is connected to each branch of the jaw by a connecting piece 208. The movable piece 210 slides so as to approach or move away from the transverse axis 207.

A second lever 238 comprising two arms is mounted vertically, pivoting around a second transverse axis 239, between the two vertical plates 220 and 221 of the lever 206. An arm of this lever is in contact with the end of the screw 237, the other with the moving part 210. Thus, by acting on the screw 237, the moving part 210 slides while approaching or moving away from the axis 207, thus making it possible to vary the torque of a given force exerted by the jaw on the lever 206 relative to the axis 207, and therefore the trigger threshold. Advantageously, the edges of the two vertical plates 220 and

221 on which the moving part 210 slides are inclined relative to the line of contact with the lateral wings 202,203 making it possible to change the initial compression of the spring 209 at the same time as the length of the lever arm, thus contributing to the change in triggering threshold .

The second lever 238 being mounted between the plates 220, 221 on one side of the transverse axis 207, a spring 209 is attached to one of its ends by means of a connecting piece articulated to a third axis 240 transverse, mounted between the plates 220, 221, on the other side of the axis 207. The other end of the spring is fixed by means of a connecting piece articulated at a fixed point of the body of fixing 201. This spring 209 is fitted onto a tube 241, in order to ensure better guidance of the spring when the latter is compressed and relaxes.

Advantageously, the articulated connection on the fixing body 201 and the tube 241 form a single piece.

In FIGS. 14 and 15, the tube 241 is the outer tube of a fluid damper 258. This damper 258 is mounted in parallel with the spring 209. The end of the rod 259 of the piston of the damper is articulated at the axis 240, and the bottom of the cylinder 260 is articulated at the same fixed point of the fixing body 201 as one of the ends of the spring 209.

In all the variants described above, the jaw has two lateral wings pivotally mounted about an axis 4. These axes can be vertical or they can slightly converge towards each other, as shown in Figure 1 6 The ends of the axes located near the ski are then more distant from each other than the other two ends giving a diagonal trajectory, slightly from bottom to top, of the lateral wings. Thus, during a rear fall combined with torsion around the skier's leg, the vertical force component exerted upward on the jaw creates torque in relation to the hinge axis of the side wing, reducing the lateral force required to trigger fixation.

It is also advantageous to tilt the vertical retaining plane of the lateral wings in order to further increase said torque created by a vertical force upwards, in order to be able to release the shoe under the effect of an associated vertical force. to a rear fall without torsion.

On the other hand, in all of these variants, an anti-friction plate 1 2, 1 1 2, 21 2 is placed on the ski boot fitting the binding.

As it goes without saying, the invention is not limited to the embodiments described above by way of example, on the contrary it embraces all variants. Thus, other arrangements of the springs, other adjustments of the position of the moving part for example are possible.

Claims

1. Front stop for alpine ski safety binding comprising a body (1; 101; 201), a jaw comprising two lateral wings (2,3; 102, 103; 202, 203), pivotally mounted around at least one axis ( 4; 104; 204) substantially vertical, and a lever (6; 106; 206) mounted pivoting about a transverse axis integral with the body (7; 107; 207) and on which the jaw, or a jaw wing, in pivoting about its axis exerts a torque, characterized in that the lever is connected to the end of at least one spring (9; 109; 209), the other end of which is articulated at a fixed point on the fixing body , the setting of the triggering threshold being effected by modifying the ratio of the distances between, on the one hand, the axis of the lever and the point of application of the spring return force on the lever and, on the other hand , the axis of the lever and the point of application of the force exerted by the jaw on the lever, acting on a moving part.

2. Front stop according to claim 1, characterized in that the lever (6) is mounted vertically in the longitudinal direction of the ski and pivots about a transverse axis (7) passing through the lever, in that the jaw or each wing side of the jaw (2, 3) acts via a connecting piece (8) on the lever (6) at an application point located on one side of the transverse axis (7), that at least one spring (9) is articulated by its ends, on the one hand, on the fixing body (1) and, on the other hand, on a threaded part (10), slidably mounted on the lever ( 6) on the other side of the transverse axis (7), which can slide perpendicular to the transverse axis (7), and in that a screw (1 1), mounted on the lever (6) and engaged in the sliding part (10) moves the latter by turning.

3. front stop according to claim 1, characterized in that the lever (6) is mounted vertically in the longitudinal direction of the ski and pivots about a transverse axis (7) passing through the lever, in that the jaw or each wing side of the jaw (2,3) acts via a connecting piece (8) on the lever (6) at an application point located on one side of the transverse axis (7), that at least one leaf spring (9) is articulated by its ends on the one hand on the fixing body (1) and on the other hand on a movable part (10) which, movable perpendicular to the transverse axis (7), is provided with a rack (53) cooperating with a rack (1 3) integral with the lever (6), locking means being provided to keep the moving part (10) in position with respect to the lever (6).

4. Front stop according to claim 3, characterized in that the locking means ensuring the maintenance in position of the movable part (10) vis-à-vis the lever (6) comprise a wedge (1 8) integral with a removable flap (1 9), mounted on the body (1) possibly forming a window, cooperating with a lug (1 7) integral with the lever (6) or with at least one lateral wing (2,3).

5. Front stop according to claim 3, characterized in that the locking means ensuring the maintenance in position of the movable part (10) vis-à-vis the lever (6) comprise a tongue (14) integral with the movable part (10), and having at least one tooth (1 5) cooperating with a second rack (1 6) integral with the lever (6).

6. Front stop according to one of claims 2 to 5, characterized in that each spring is formed by a spring leaf (9) made of composite material with fibers mainly unidirectional in the longitudinal direction, possibly with fibers crossed at about 90 ° near the neutral axis.

7. front stop according to claim 6, characterized in that the spring blades (9) are of constant thickness, except at the ends where they are rounded, forming an arc of a circle whose center is offset from the axis neutral of the blade, and in that these blades are wider in the center than at the ends, so that in maximum bending each blade is deformed according to an arc of a circle, that is to say has a constant radius of curvature .

8. Front stop according to claim 1, characterized in that the lever (106) comprises two parallel flat plates (1 20, 121) in the shape of "L", which are placed vertically in the longitudinal direction of the ski and spaced the one from the other, and a flat plate (1 22) connecting two branches of the two L-shaped plates and perpendicular to them, in that the lever (106) pivots about a transverse axis (107) through the end of the connected branches of the L-shaped plates, in that the spring (109) is a helical spring articulated at one of its ends at a fixed point of the fixing body and by its other end at the ends unconnected branches of plates (1 20, 121) in the form of "L", in that a sliding part (1 10) which can move towards or away from the axis (107) around which the lever (106) pivots is guided on the flat plate (122) connecting the two plates in the shape of "L", and in that the jaw (102, 103), or each wing of the jaw acts on the lever (106) via a link bar (108) articulated d 'firstly on the jaw, or a wing of the jaw (102, 103), and secondly on the sliding part (1 10).

9. Front stop according to claim 1, characterized in that the lever (206) comprises two parallel flat plates (220, 221) interconnected, which are placed vertically in the longitudinal direction of the ski and spaced one of the other, in that the lever (206) pivots about a transverse axis (207) passing through the two parallel flat plates of the lever near the center of these, in that a sliding part (210) which can move approaching or moving away from the axis (207) around which the lever pivots, is guided between the two flat plates (220, 221) and is connected to the jaw (202, 203), or to each wing of the jaw, via a connecting piece (208), in that the spring (209), one end of which is articulated at a fixed point of the fixing body (201), is a helical spring, the other end of which is articulated at one end of each plane plate (220, 221) of the lever, so that at the other he end of the lever is mounted, between the flat plates, on an axis (239), a lever (238) movable in rotation, one arm of which is in contact with a screw (237) mounted in the first lever (206) and which comes, via another arm, in abutment against the sliding part (210), in order to be able to slide the latter on the edges of the flat plates (220, 221).

10. Front stop according to one of claims 2, 8 and 9, characterized in that, in the case where the spring is a helical spring (109, 209), it is fitted on or in a tube (241) .

1 1. Front stop according to one of claims 1 to 10, characterized in that the axes (4; 104; 204) around which pivot the wings of the jaw converge slightly towards each other upwards.

12. Front stop according to one of claims 1 to 1 1, characterized in that it comprises a fluid damper (258) mounted in parallel with the spring (209), between a fixed point on the fixing body and the lever (206).

13. Front stop according to claim 1 2, characterized in that, in the case where the spring (109, 209) mounted between the fixing body (101, 201) and the lever (106, 206) is a helical spring, it is fitted on the fluid damper (258), which serves as a guide.

14. front stop according to one of claims 1 to 13, characterized in that it comprises a second lever (70) pivotally mounted about an axis (76) substantially parallel to the transverse axis (7) of the first lever (6), a first end (77) of this lever (70) being intended to be placed under the front end of a shoe for a skier and the second end (78) of this lever (70) being intended to lodge in a notch (71) made in the first lever (6).