Technical problem A technical problem solved by this invention is how to conceive such a connecting device for a ski and ski boot binding which will offer a stiff basis for a ski boot binding and at the same time dampen the transfer of oscillations (vibrations) of a ski which appear in turns owing to gliding especially on hard and uneven snow and ice whereby it will have a minimum influence on the properties of a ski and will at the same time be simple and cheap.

State of the art Several connecting devices for ski and ski boot bindings are known. They differ among themselves in elastic elements dampening the vibrations of a ski. Their similarity lies in the fact that the connecting devices are fixed to the ski at both ends, whereas the ski boot binding is screwed up to the upper panel of the binding device. Due to price effectiveness it is assumed that only one type of such a binding device is manufactured for all sizes of boots and bindings. A distance between the screw fastening of the connecting device and the fastening of the ski boot binding on the upper panel, which increases with the size of the boot diminished, causes an additional bending effect on the upper panel of the connecting device which decreases its required stiffness. The stiffness of the upper panel is required in order to assure that the boot is fixed into the binding with the same force in all positions of a ski during skiing. With this panel bent, the toe and the heel unit of the binding spread and close thus decreasing or increasing the manually set force at which the binding is supposed to loosen (unfasten) the boot.

Another essential disadvantage of all the described connecting devices, originating from their length foreseen for the largest size of boots and thus for the largest skis, lies in the fact that, with medium and short size skis, it occupies a relatively long section on the central part of a ski thus shortening the section of the toe and heel of a ski which freely oscillate. The more the points where the connecting device is clamped reach the toe or the heel of a ski, the more a relatively stiff connecting device (despite elastic inserts) influences the performances of the toe and heel of a ski, not only in the sense of the desired dampening of oscillations but also in the sense of undesired change of the elasticity of a ski as foreseen by the manufacturer.

An obvious solution of this problem, namely a manufacture of a product line of connecting devices dimensionally adapted.to each size of a ski boot and to dimensionally various bindings, is too expensive. Technical advantages would not justify a higher price which is influenced not only by a number of sizes of a connecting device but also by the increased costs resulting from a larger stock a seller and repair personnel should keep.

For this reason the only sensible connecting device is such that could simply be adapted in the sense of the shortest length possible with respect to different sizes of boots and bindings so that it essentially decreases the effect of the stiffness of the connecting device to a ski due to the points where it is fastened to a ski.

Solution of the technical problem A solution of the technical problem solved by the present invention lies in the fact that the connecting device consists of three pieces, namely of a central hollow flat profile on which an optional binding for a boot is intended to be placed, and of two, preferably the equal fastening elements including also the inserts for the dampening of ski oscillation. The flat profile of the connecting device is adapted to each size of a boot and the binding during the process of mounting the connecting device and the binding onto a ski. The fastening elements are to be fastened only in a form-locking way without any tools or binding means at the front and back ends of the flat profile. The connecting device assembled in this way is mounted onto a ski. The connecting device is then ready for the bindings to be placed in known manner.

The flat profile is preferably hollow in order to reduce weight and in order for the cross- sections of the bright sides of both ends to be directly adapted as the bearings of the fastening elements without additional machining.

To prevent snow from entering the gap between the flat profile and the ski and in order to increase the stiffness of the profile, the latter can be formed as a U-profile with a hollow transversal strap having the same function as said flat profile. The side free straps strengthening the profile are oriented downwards and enclose the side surfaces of the ski. In this part the ski can have side flat deepenings in which lie the side straps of the profile. Such integrally designed solution increases the aesthetic appearance of the ski with the metal parts and does away with the undesired resistance in deep snow which can be caused by the side straps projecting from the flat area of the side surfaces of the ski.

The fastening elements include two elastic intermediate pieces through which the fastening elements and the flat profile are connected in order for the transfer of ski vibration to the flat profile and thus to the boot and the skier to decrease.

In this way only two semi products are manufactured: the flat profile and the fastening element which are held in stock by sellers and servicemen. When mounting the bindings the flat profile has to be cut to the size suitable for the size of the boot and the binding, and into the opening of the connecting device a binding is to be inserted, with which the connecting device is ready to be mounted onto a ski and then suitable for a binding to be screwed thereon.

An elastic bridging insert in the fastening element has an optional property of dampening.

The described multipartial concept offers a possibility of simple manufacturing and, if required, optional composition of the connecting device with a various degree of dampening.

The invention will be described in more detail with two embodiment examples shown in the enclosed drawings, showing Fig. 1 top view of the binding according to the first embodiment and in exploded view; Fig. 2 top view of the binding according to the second embodiment and in exploded view; Fig. 3 longitudinal cross-section of the binding along the line III-III of Fig. 2; and Fig. 4 transversal cross-section of the flat profile according to the third embodiment placed on a ski.

The first embodiment A connecting device of a ski and a ski boot binding according to the first embodiment consists of a flat profile 1 foreseen for the fastening of an optional ski boot binding which is not shown in drawings, and two fastening elements 2 foreseen to be mounted on a ski A whereby the profile 1 and the fastening elements 2 are connected in a form-locking way.

The flat profile 1 is preferably hollow in order to reduce weight of the entire object. The thickness of its wall is such that the screws of the binding reach the required extruding force. At front ends there are openings 3 foreseen as a bearing of the fastening elements 2 which are described in more detail in the continuation.

The fastening elements 2 are formed as small short flat elements of at least three layers: a lower layer 4 foreseen to be laid on the ski A and directly fastened to same with screws 5 lying in drilled holes 5', then a middle dampening layer 6 which is elastic and intended to dampen the vibrations of the ski, and an upper layer 7 which is prolonged to the side with a tongue 8 intended for a tight fitting into a front opening 3 of the flat profile 1. An elastic ring 9 is placed on the tongue 8, the ring assuring a tight contact of the profile 1 and the element 2.

The height of the fastening elements 2 or their tongues 8, respectively, is such as to determine a suitably prescribed largest allowed distance between the gliding side of the ski and the upper surface of the connecting device on which a binding and a boot are placed.

Under the profile there is a free gap that can be filled with a light insert in order to prevent the collecting of snow.

The middle dampening layer 6 of the fastening elements 2 is preferably made of rubber, it can also be made of an optional elastic material. The dampening layer 6 is placed between the lower layer 4 and the upper layer 7 in order to enable damping of the vibrations of the ski regardless of the direction of forces causing vibrations. All three layers of the fastening elements 2 are connected by vulcanization or gluing.

The fastening elements 2 are formed in a way to offer an optional external shaping without decreasing the described application characteristics. They are preferably shaped as a wedge in order to prevent the collecting of snow thereon, in front of them, or behind them.

The second embodiment The second embodiment of the connecting device according to the invention is made of the same flat profile 1 with front openings 3 as described in the first embodiment. Fastening elements 20 which are also foreseen for placing the connecting device to a ski A, are made as lying U-profiles. The lower free strap 21 of the element 20 is foreseen for the laying and fastening to the ski A. The opposite, i.e. the upper free strap 22 is prolonged with a tongue 23 foreseen for the mounting into the openings 3 of the profile 1. In the upper strap 22 there are two larger drilled holes 24, through which fastening screws 25, which lie in openings 26 made in the lower strap 21, are placed.

On the tongue 23 there is an elastic element 27 fitting to the opening 3 of the profile 1. The element 27 is made as a ring with an outer circumference 28 lying between the profile 1 and the binding element 20. This ensures a good contact between the flat profile 1, on which a boot is placed, and the fastening elements 20 only through the elastic element 27 dampening the vibrations of the ski regardless of the direction of the force causing vibrations.

The operation of the connecting device can be adapted to individual needs in a simple and cheap way by replacing the elastic element 27 by another one having the same dampening characteristics of vibrations. Other application advantages of the second embodiment equal those according to the first embodiment, i.e. simple and cheap longitudinal adaptation of the connecting device to the size of a boot, minimal number of various constituent parts in stock both at the manufacturer's and seller's/serviceman's.

The third embodiment The third embodiment of the connecting device is embodied of the fastening elements 2 or 20 according to the first or second embodiment. A profile 30 is embodied in a different way, namely in the sense of a U-profile, the transversal strap 31 of which is hollow in order to allow the fastening elements 2 or 20 at its ends. The side straps 32 increasing the stiffness of the profile, are oriented downwards and embrace the central part of the ski A. The ski A can here be made with side flat holes B in which lie side straps 32 so that the external side contour of the ski is preserved and does not represent an additional resistance especially in deep snow.

All embodiments described above can be carried out in known technological manner. It is simplest and cheapest if the flat profile is manufactured in batch production as a profile made of aluminium or an artificial material by extruding. The fastening elements or better their metal parts may suitably be made of known profiles with additional machining. In the first embodiment, vulcanisation is used to connect both metal parts with a rubber intermediate elastic layer, with the second embodiment an elastic element is manufactured specially in known manner whereby said elastic element is manually placed onto the tongue of the fastening element during mounting onto the ski.

Knowing the described essence of the invention it is understandable that a person skilled in the art can design other embodiments without circumventing the essence of the invention defined in the attached patent claims.