Accordingly, the invention is based on a problem, how to avoid considerably, if not completely eliminate negative consequences of vibrations generated unavoidably during skiing, especially in such a way, that the present physical characteristics of the ski, which are necessary and required by regular use thereof, would not be essentially affected in any way, and that any measures in this course would be carried out in a practically unnoticeable way, i. e. without any outwardly visible additions and moreover with as simple means as possible.

Those skilled in the art are aware, that during skiing the ski is exposed to vibrations. These result from forces generated, for example, due to the weight of the skier, reactions when running in curves, configuration of the ground and the elasticity of the ski itself. The intensity of vibrations and consequences thereof depend among others on the mode of skiing and of course on the quality of the ground surface. One of possible impacts is, that the said vibrations result certain changes in the intensity of forces acting on the edges of the ski, due to which the ski is exposed to tendency of sliding away from the direction, which can result in common known troubles and sometimes even injury of the skier. Another consequence of the vibrations is, that the vibrations and the related adequate dynamic loadings are transferred from the ski over the bindings and the ski-boot towards the musculature and especially to the skeleton of the skier. Zealous skiers may therefore gradually start to suffer from damages to the skeleton, especially the spine, which is undoubtedly the result of the vibrations observed.

Already in the past several solutions were known, which were all proposed with the intention to damp these vibrations as much as possible and to avoid of the said damages and injuries in this way. These solutions are described e. g. in EP 0 437 142 A1 and US 4,896,895 as well as in EP 0 574 640 Al and also in US 5,242,188.

The solution according to EP 0 437 172 A 1 presents in fact a support of the binding, intended for ensuring mutual connection between the ski and the ski- boot. Already in this solution-evidently under the awareness of the problem of the said vibrations-a damping element has been used; it was placed between the top surface of the ski and appropriate plate, which was located in the area of fastening of the ski-boot to the ski and extended in the longitudinal direction of the ski at certain distance from the top surface of the ski. The said solution presents in fact an accessory, which can be subsequently added to before that already finally manufactured ski. On the one hand this accessory is a universal one and can be used in the same form with all forms and designs of skis, while on the other hand it is visible outwardly, so that it always raises a question, to what extent each such supplement may change exterior of the ski, which is also a result of hard and carefully work of designers. Each such accessory added onto the outer surface of the ski, means also certain increasing of the weight of the ski, and besides, can also generate certain complications during skiing, either due to the snow or ice, which is retained in certain parts of the ski equipment, or due to a danger of entangling into various objects available along ski slopes or even into parts of clothes, especially during a fall, shifting of skis, during transport and in similar situations. Besides, any of such accessories is fastened to the ski in a certain way and on certain locations on the ski, which may also result considerable consequences in change of the elasticity of the ski and the mode of its own oscillation respectively of its fundamental frequency. Thus, adding such an accessory certainly results in a favourable attenuation of vibrations transferred from the ski to the skeleton of the skier, but on the other hand it results a considerable alteration in the regime of oscillation, by which important changes of physical and manoeuvring characteristics of the ski may occur.

Furthermore, in the US 4,896,895 there is described a device for damping of oscillations, vibrations, and impacts during skiing, which consists of an impact absorption layer, an appropriate metal plate, placed over the said layer, as well as of a layer of pressure sensitive adhesive, which is spread on the said layer, namely on the side facing towards the top surface of the ski. The device designed in this way should damp oscillations, vibrations and impacts, and in this way it should improve the manoeuvrability of such skis. The metal plate has a bridge-like design, so that it resta on the upper surface of the ski on two locations. It is fixed immovably on one location, while on the other location it is fixed in such a manner that it can be moved in the longitudinal direction of the ski. The dimensions of the plate, i. e. length etc., enable fixing appropriate ski binding thereon. Although such a device should ensure a maximally free and undisturbed bending of the ski under the plate, the physical characteristics of this very ski as such and the ski with an absorption layer and the said metal plate fixed on it, differ from each other substantially without any doubt, because the distances between the locations of the fixing on the ski in the two mentioned cases differ by at least a length, which is necessary for fixing of the bindings. Again, this causes a change in the oscillation regime and with it in the manoeuvrability of the skis. On the other hand it will be understood, that on the one hand use of metal plates results undesired increasing the weight of the skis, and that on the other hand the number of required fixing points is doubled, which of course doubles the risk of troubles caused by unscrewing or even of pulling-out the screws and similar. Again, such a supplement is visible outwardly and inconvenient, and besides, its compatibility with the ordinary form of the ski is always questionable and bound to certain problems.

Another solution of damping oscillations in skis is known from the EP 0 574 640 A 1. The solution of the same inventor as by those in accordance with US US 4,896,895, means an upgrade of the latter, for it again proposes a metal plate, under which a layer of some elastomeric material should be placed; the layer rests on the upper surface of the ski. The said elastomeric layer is provided by cavitations obtained for example by means of crosswise arranged ribs. In the said cavitations a kind of cells filled with air should be available, which should additionally damp the vibrations generated during skiing. This solution might really offer more effective vibration damping as the previously mentioned solutions, however, all the previously enumerated problems in connection with the increase in weight, change in the mode of fixing, inconvenience, increase in risking potential defects, questionable outward appearance etc. remain entirely unsolved.

In the US 5,242,188 a removable plate for fixing the ski bindings is described.

The said source deals with the idea, how to provide the same user with a possibility of using various skis without any need of executing the always time consuming and demanding remounting of ski bindings. The said solution applies a component intended for damping of impacts and vibrations as well, but all exposed problems in connection with the increase in weight, change in the mode of fixing, inconvenience, increase in risking potential defects, questionable outward appearance etc. remain further present.

The present invention relates to a ski having a forward portion with curved end area, an essentially straight rear portion and a central portion, which is bent gently in a direction away from the ground, where an appropriate sliding surface is arranged on the bottom side of the ski and limited with two appropriate ski edges extending along the ski. Furthermore, an appropriate surface for placing the ski-boot and for fixing the ski bindings is available on the top side in the area of the central portion of the Moreover, the core of the ski in the central part is adapted for taking over bending and other loadings occurring during regular use of the ski. If desired, such a ski may be equipped by a plateau arranged on the central portion of the ski, i. e. by the so called platform, designed mainly for the purpose of increasing the height, i. e. the thickness of the ski in the said central portion. The ski according to the invention comprises in its interior a vibration damping layer, which is preferably placed under an area available on the top surface of the central portion of the ski, which is foreseen for placing the ski-boot and fixing appropriate ski bindings. However, the said vibration damping layer can be placed either between the core and the plateau or in even the core itself e. g. in the case of the absence of the plateau. Furthermore, the said layer is made of appropriate elastomeric material, preferably of rubber. In this way, the layer placed inside the ski is totally unnoticeable and so non-disturbing.

Now, the invention will be described and explained in more detail on the basis of the embodiment shown in the accompanied drawing, where Fig. 1 is a top plan view of a ski according to the invention; Fig. 2 is elevation view of the ski; and Fig. 3 is a cross-section of the ski in the plane III-III according to Fig. 1.

As shown in the Fig. 1 and 2, the ski according to the invention is manufactured as an integral group of components, bent slightly away from the direction of the ground, with a suitably and conveniently conceived outward form. The forward portion 1 of the ski is bent in the direction away from the ground and at the utmost end 10 of the forward portion 1, the ski is preferably equipped with an appropriate protective means 11. On the utmost end 20 of the rearward portion 2, i. e. on the so called tail, a protective means 21 is arranged in a given case as well.

The central portion 3 of the ski, which is bent in the direction away from the ground, is designed with an appropriate core 31 (Fig. 3) and is usually slightly thicker or higher as the forward portion 1 and the rearward portion 2 of the ski.

The reason for this is of quite physical nature and is based on the loading state occurring by a beam supported in two points and loaded with a centrally distributed transverse loading. Such a thickening of the central portion 3 of the ski is generally known and logical. Thereby, several embodiments of the said core 31 are possible. In the past the core 31 was made exclusively of wood, later of synthetic material, aluminium and some other kinds of metals and alloys, as well as of adequate combinations of components, i. e. combinations of the said materials. However, for the purpose of this description, the term"core" 31 should be understood as to designate an integral or a combined group of materials forming the cross-section of the central portion 3 of the ski, which is generally capable to take over bending and other loadings, to which the ski is exposed during its regular use.

In the central portion 3 on the top side 4 of the ski a plane area 5 is foreseen for fixing the ski bindings, which are not shown in the drawing, and for placing the ski-boot, which is also not shown in the drawing and which can be attached on the ski by means of the said bindings. On the bottom side 6 of the ski a sliding surface 7 is provided, where two appropriate edges 8,9 are arranged along the lateral margins of the said sliding surface 7 on the bottom side 6 of the ski.

Especially by the skis used in the last time, i. e. by the carving-skis comprising expressive turning edges, there is a tendency, that the thickness/height of the central portion 3 of the ski should be considerably greater than a usual thickness or height. By such a ski the width of the sliding surface 7, i. e. the distance between the edges 8,9 in the transverse direction on the front portion 1 or the rear portion of the ski 2 is considerably greater than the width of the central portion of the ski 3. Thus the edges 8,9 are distinctively curved, by which correctly transferring of weight of the skier from one to the other edge 8, 9 enables appropriate manoeuvring of the ski along a curved-line route with relatively small curvature radius. In this way the manoeuvrability of such skis can be really excellent.

To this aim, the central portion 3 of this ski kind is preferably equipped by a suitable plateau 30, which is foreseen-to provide an appropriate area 5 for placing the ski-boot and fixing the ski bindings on the one hand, and moreover a desired height of the central portion 3 on the other hand. In order to avoid increasing of the ski width and herewith also the weight of the ski, and simultaneously due to tendency of ensuring as great as possible ratio between the widths of the sliding surface 7, or the distances between the edges 8,9 in the transversal direction on the forward portion 1 and the rearward portion of the ski 2, and the width of the central portion 3 of the ski, it is reasonable to reduce as much as the width of the sliding surface 7 of the central portion 3 of the ski. However, it is necessary to ensure a sufficient width of the area 5 on the top side 4 of the ski, where a ski-boot has to be placed in a regular manner and the width of which is therefore such as it actually has to be. Therefore, arrangement of the plateau 30 on the central portion 3 seems to be an optimum.

Such a plateau 30 extending from the forward portion 1 to the rearward portion 2 of the ski, as shown also in the Fig. 1 or 2, in each case enables quite uniform distribution of loadings along the complete functional surface of the top side 4 of the ski and thus by appropriate design of the ski, it should not result any essential change with respect to distribution of forces or to elasticity or also other physical characteristics of the ski as such.

Nevertheless, vibrations in general unavoidable occur during skiing also with the described design of the ski, where on the one hand these vibrations cause sliding-away of the actually loaded ski edge 8,9 from the desired direction, while on the other hand also the skier is exposed to intensive dynamic stresses.

In order to reduce said sliding-away, it is in common necessary to increase the force pressing the edge 8,9 towards the ground, the consequence of which are even much more intensive stresses to which the musculature and skeleton of the skiers are exposed. Due to problematic vibrations the loadings are therefore much more intensive and more inconvenient. Of this reason, the ski according to the invention is equipped with a damping layer 35 placed in its interior at least in the area of the central portion 3, especially under the area 5, which is foreseen for placing the ski boot. This damping layer 35 is built-in either between the core 31 and appropriate conceived plateau 30 (Fig. 3) or even in the core 31 itself, which is not separately shown in the drawing.

The said damping layer 35 is preferably made of elastomeric material, preferably of rubber. In such a manner by the skis according to the invention, the vibrations occurring on the actually active edge 8,9 can be transferred through appropriate areas of the core 31 to the layer 35, where the vibrations are dampened. On the surface 5 above the said layer 35, the effect of the vibrations is therefore so weak, that the loadings to which the body of the skier is exposed can be essentially reduced with respect to those occurring in the absence of the layer 35.

With the ski according to the invention the said layer 35 may be quite invisible, therefore it is possible with this kind of the ski, to eliminate negative impacts of vibrations which unavoidably occur during skiing, in an outwardly almost invisible way, e. g. without any visible additions and with actually simple means, as well as without any essential modifications of the usual physical ski characteristics, required and necessary for any regular mode of its use.