Background Art It is known that modern ski bindings are required to allow the immediate release of the toe and/or heel of the user's sports shoe, upon exceeding a pre- established stress level between the ski and the user's leg.

For this aim, known ski bindings are fitted with suitable releasing mechanisms whose activation level basically depends on the user's weight.

In particular, the toe unit of a modern ski binding is usually fitted with one or two jaws, which are shaped so as to accomodate the toe of the sports shoe.

Upon being released, the jaws can rotate with respect to an axis perpendicular to the ski, thereby facilitating the shifting of the toe of the sports shoe in a transverse or vertical direction with respect to the longitudinal axis of the ski.

The main drawback of such known types of ski binding consists in that the contact area between the toe of the sports shoe and the underlying ski (or interconnection plate connected to the ski) must present a very low friction coefficient value in order not to hinder such release movement. In fact, a slowdown in the release of the sports shoe from the binding structure may have harmful consequences for the safety of the user, since the contrasting forces between the ski and the leg of the user are frequently the reason of serious injuries, for example to the knee ligaments.

The aforementioned problem is partly solved by the use of anti-friction plates, which may be mounted on the upper surface of the ski, so as to underlie the sole of the sports shoe. Such anti-friction plates are, for example, made of a plastic material with a low friction coefficient.

Alternatively, the use of bearing devices provided with a sliding member is also known. These devices generally comprise a plate, which is provided at the bottom with means of sliding along an axis, which is transverse to the

longitudinal axis of the ski proper. For example, it is known to use idle rollers, pivotally positioned within respective seats, on which the plate can slide. Furthermore, it is known to use idle cones, positioned with their longitudinal axes not parallel to each other but converging on a single point, corresponding to the supposed position taken by the user's heel.

These known types of bearing devices however, suffer the serious drawback of not following, in a satisfactory manner, the exact movement of the sports shoe during its release from the ski binding. For example, in case of an excessive force applied to the front area of the ski in a certain direction, the jaws of the toe unit of the ski binding are forced to turn in an opposite direction, causing the simultaneous rotation of the sports shoe around the heel, in such a way as to permit the release of the heel of the sports shoe. Generally, known bearing devices provided with idler rollers, do not help this rotation, since the movement of the sliding plate is consistent with the movement of the sports shoe only for a very short initial distance.

Similarly, bearing devices provided with idle cones bring a certain advantage only if the size of the sports shoe is within a certain narrow range, according to which the sports shoe rotates around a point, which approximately coincides with the intersection point of the longitudinal axes of the cones. Therefore, the greater the difference between the actual size of the sports shoe and the size predefined during the design phase, the lower the effectiveness of the release action guaranteed by the bearing device of the ski binding structure.

It is known also to use bearing devices provided with complex mechanisms for guiding the movement of the sliding plate, which include, for example, articulated rods. The main drawback of these solutions resides in their intrinsic structural complexity, which often entails high costs and reduced reliability.

Finally, it is known to use sports shoes having at the bottom a rigid sole, made of a plastic material with a low friction coefficient. The main

drawback of this kind of solution consists in that the user's gait is often quite difficult, due to the low grip of the sports shoe on snow-covered or icy surfaces. It should be noticed that it is difficult to solve this problem by providing the sole of the sports shoe with inserts of resilient materials, since these materials generally present high friction values, which do not comply with the common standards.

Disclosure of the Invention Therefore, the aim of the present invention is to provide a ski binding, which guarantees a safe release of the sports shoe, to which it is associated, regardless of the size of the sports shoe.

Within this aim, an object of the present invention is to provide a ski binding, which guarantees a safe release of the sports shoe, to which it is associated also when such sports shoe is provided with a sole at least partially made of materials with a relatively high friction coefficient.

Another object of the present invention is to provide a ski binding, which is structurally simple and has low manufacturing costs.

Thus, the present invention provides a ski binding comprising: - a toe unit ; and - a bearing device, arranged approximately to the rear of the toe unit, said bearing device comprising a sliding plate, which underlies the sports shoe of the user when the sports shoe is associated to the ski binding, characterised in that such bearing device comprises guiding means for guiding and supporting the sliding plate, the guiding means being arranged so as to allow the sliding plate to perform, with respect to the ski, a rotary- translation movement, which is automatically adaptive to various sizes of the sports shoe.

Brief description of the drawings Further characteristics and advantages of the ski binding, according to the present invention, will become better apparent from the following detailed description of some particular embodiments thereof, illustrated by way of

non-limitative example in the accompanying drawings, wherein: Figures 1 and 2 are perpsective views of a bearing device included in the ski binding, according to the present invention; Figure 3 is a partially sectional view of the bearing device of figures 1 and 2; Figure 4 is an exploded view of the bearing device of figures 1 and 2; Figure 5 is an exploded view from below of the bearing device of figures 1 and 2; Figure 6 is a side view of the bearing device of figures 1 and 2 and a toe unit, included in the ski binding, according to the present invention; Figure 7 is a plan diagram, schematically illustrating the operation of the ski binding, according to the present invention, for sports shoes of different sizes.

Ways to carrying out the Invention With reference to the figures, the ski binding 100, according to the present invention, comprises at least a toe unit 4 and preferably a heel unit (not shown), which are designed to temporarily retain a sports shoe 101 on a ski (not shown). The toe unit 4 is advantageously fitted to the rear with a pair of jaws 5 shaped approximately like a"V"in order to accomodate the toe 102 of the sports shoe 101. The jaws 5 are pivotally mounted on the toe unit 4, so as to permit their outwards opening and therefore the release of the toe 102 of the sports shoe 101 from the ski binding 100 upon exceeding a pre-established stress level. The ski binding 100 comprises a bearing device 1, which comprises at least a sliding plate 12 underlying the sports shoe 101 when it is associated to the ski binding 100.

The bearing device 1 comprises guiding means 6,8, 9a, 9b that are arranged to allow the sliding plate 12 to perform, with respect to the ski, a rotary-translation movement, which is automatically adaptive to various sizes of the sports shoe 101. Preferably, such guiding means comprise a base block 6, which may be mounted on the upper face of the ski, approximately

to the rear of the toe unit 4. The base block 6 comprises advantageously at least a transverse guide 9a, which is provided with a discontinuous stepped profile to permit a rotary-translation movement between the sliding plate 12 and the base block 6.

According to a preferred embodiment of the present invention, a guide element 8 protrudes upwardly from the base block 6 near its rear end 7. The guide element 8 has, in a view taken according to a longitudinal section, an advantageously approximate"T"shape, the flanges of which define a first and a second transverse guide 9a and 9b. Between the first and second transverse guides 9a and 9b, on the opposite side to the vertical element 50, the grooves 51a and 51b can be suitably provided. A first seat 10 of suitable shape and size may be provided between the grooves 51a and 51b. A first pair of wedges lla and lib protrude from the opposite ends of the grooves 51a and 51b. A sliding plate 12 is advantageously connected to the top of the guide element 8. The sliding plate 12 has preferably a plan shape that is approximately rectangular and has at the bottom a second seat 13, shaped around the guide element 8, so that it may accomplish a rotary-translation movement along the same. The sliding plate 12 advantageously comprises an upper cover 12a, at the bottom of which an anti-friction plate 12b can be connected for insertion between the cover 12a and the upper surfaces 14a and 14b of the first guide 9a and the second guide 9b. The anti-friction plate 12b is, in practice, designed to provide anti-friction means between the sliding plate 12 and the base block 6 in particular the guide element 8, since it can be advantageously made of a material with a low friction coefficient in order to be able to rotate-translate freely along the guide element 8. The anti- friction plate 12b is preferably provided with a third seat 15, which is shaped approximately as the first seat 10. From the top of the third seat 15 a second pair of wedges 16a and 16b, having similar shape and size to the first pair of wedges lla and llb, can protrude. Particularly, the wedges 16a and 16b can be arranged so as to lie on a plane, which is substantially parallel to the plane

on which the first pair of wedges lla and llb are arranged to lie.

A resilient element, such as a helical spring 17, housed in the first and third seat 10 and 15, may be suitably positioned between the first and second pairs of wedges lla, llb, 16a and 16b.

In this way, subsequent to a movement of the sliding plate 12 that preloads the spring 17, the spring 17 provides, in practice, resilient recovery means positioned between the base block 6 and the sliding plate 12. As illustrated, this resilient recovery means are designed to permit the recovery of the sliding plate 12 above the guide element 8 of the base block 6.

The first guide 9a is shaped so that it has a first outer edge 18a, whose profile is not linear. In fact, the first outer edge 18 is provided with a cutout 18a, so as to form two opposite stepped areas 20a, 20b and approximately at its ends 19a and 19b. In particular, at the ends 19a and 19b of the first outer edge 18a, each of such stepped areas comprises a first section 20a, arranged parallel to the second outer edge 18b of the second guide 9b, and a second inclined section 20b, connected to the first section 20a.

Operation is therefore as follows: when the sliding plate 12 is located above the guide element 8, their interconnection is not pivotal since both the first sections 20a are housed inside the second seat 13 of the sliding plate 12.

Once the release operation of the ski binding 100 starts, the rotation of the jaws 5 occurs at the same time as the first greatly reduced translation or traverse movement of the sliding plate 12 and more precisely corresponding to approximately the length of the first section 20a. Once this first movement has finished, the sliding plate 12 is free to rotate around a point 200 that is substantially the actual centre of rotation of the sports shoe 101 during its release from the ski binding 100. This free rotation, which occurs regardless of the distance between the sliding plate 12 and this centre of rotation 200, permits a rotary-translation movement between the sliding plate 12 and the ski, and of course the base block 6, which is automatically adjusted to the size of the sports shoe 101. Therefore, the sliding plate 12 is free to rotate

regardless of the size of the sports shoe 101 since the position of the centre of rotation 200 varies depending on the size of the sports shoe, as shown in Figure 7.

It has thus been observed that the ski binding structure according to the present invention achieves the aim and objects since it ensures a safe release of the sports shoe 101, regardless of its size. Also, the release of the sports shoe 101 can happen regardless of the fact that the sole of the sports shoe may slide with respect to the bearing device, since the movement is guaranteed by the movement of the sliding plate 12. Thus, the release of the sports shoe 12 is equally safe and effective even if the sports shoe comprises a sole made of resilient materials having a relatively high friction coefficient.

Finally, the ski binding structure, according to the present invention, is structurally very simple and inexpensive to produce, since the number of components of the bearing device is relatively low and can be easily manufactured.

The disclosures in Italian Patent Application No. TV2001A000095 from which this application claims priority are incorporated herein by reference.