Description:
This invention relates to a low friction bearing arrangement for a ski boot in contact with a ski.
Various means are known which permit release of a skier's ski boot from his ski binding when he experiences a fall which twists his leg while limiting the uncertainties due to the coefficient of friction between the ski boot and the ski. These means consist of, for example, an assembly of moveable parts secured to the ski and adapted for rotation or translation, or of a fixed part made of a material having a low coefficient of friction secured to the ski.
In the first instance, the assembly is relatively expensive, fragile and may be hindered in its operation by the presence of small stones. In addition, the ski boot is raised with respect to the ski by the thickness of the above-mentioned elements, and this is detrimental to the practice of the ski sport in accordance with modern techniques.
In the second instance, the sole of the ski boot has a rugged surface and patterns adapted to prevent the sliding of the boot on snow or ice when walking without skis. Thus to try to improve the sliding of the sole of a ski boot on a ski while, at the same time, trying to prevent the sliding of the same ski boot when walking on snow or ice presents a delimma. In addition, the rugged surface of the sole may catch small stones thus increasing the friction of the sole of the ski boot on the ski.
The main feature of the present invention is to overcome the above-mentioned drawbacks in a simple and effective manner.
In the arrangement in accordance with the invention, the soles of the ski boots have, at the location where they contact the skis, one or more substantially transversal slots which are relatively narrow, advantageously smooth, and devoid of patterns to prevent the catching and holding of small stones therein capable of hindering the sliding of the ski boots on the skis.
The arrangement in accordance with the invention includes the attachment, to the skis, of friction plates corresponding to the slots in the soles of the ski boots. These plates permit the contact of smooth rubber or plastic elements with an equally smooth surface of metal or plastic.
A plate having a high coefficient of resistance to wear or to oxidation may be inserted or molded in each slot in the sole. Stainless steel may, for example, be used for such plate.
In order to hinder the least possible the task of walking with the boots in accordance with the invention, the slots are preferably not located in the normal bearing area of the sole on the ground.
The invention will now be disclosed in detail in the following description with reference to the accompanying drawings which illustrate, by way of example, preferred embodiments of the invention in which:
FIG. 1 is a perspective bottom view of a ski boot in accordance with the invention, only the sole of the boot being shown;
FIG. 2 is a perspective top view of a ski including part of the arrangement in accordance with the invention;
FIG. 3 is a side view of the whole arrangement, in a simple embodiment of the invention;
FIG. 4 illustrates a detail of the arrangement shown in FIG. 3; and
FIG. 5 illustrates a second embodiment of the arrangement in accordance with the invention permitting a better resistance to wear.
In FIG. 1, the bottom of a sole 1 is provided with two slots 2 and 5 having smooth bottom surfaces, the depth of each slot being identified by reference numeral 9 and the width thereof by reference numeral 4. The slot 2 is disposed at a distance 3 from the front end of the sole corresponding to one third of the length of the sole, and the slot 5 is located in the heel of the boot.
The slot 2 has parallel edges which are shown as being straight. However such edges may be curved. Similarly, the bottom of slot 2 may be flat or curved.
In FIG. 2, the ski 6 includes a friction plate 7 made of metal or plastic and secured to the ski by means of two countersunk screws 12. The central axis of plate 7 is located at the same distance 3 mentioned in the description of FIG. 1 from the bearing surface of the front ski attachment 14. The width 8 of the plate 7 is less than the width 4 of the slot 2. The height 11 of the plate 7 is greater than the depth 9 of the slot 2.
The friction plate 7 preferably has a shape corresponding to the shape of the slot 2 in the sole of a ski boot.
FIG. 3 illustrates the assembly on a ski 6 of a sole 1 comprising two transversal slots 2 and 5 bearing on the corresponding friction plates 7 and 17.
In FIG. 4, it may be seen that the contact area of the sole 1 with the ski 6 is limited to the upper surface of the plate 7 creating the gap 10 between the normal surface of the sole and the ski. This gap 10 may, however, be of relatively low value. The small stones will practically have no tendency to remain on the smooth surface of slot 2, in contact with friction plate 7, the gap 10 permitting, on the other hand, their release from the space between the sole of the ski boot and the ski.
By means of a proper choice of material, there may be obtained a low coefficient of friction between the plate 7 and the bottom of the transversal slots of the sole 1. Thus conditions for minimum friction are provided to permit a good lateral operation of the ski binding.
In FIG. 5, a boot plate 13 is inserted or molded at the bottom of slot 2 to protect such slot from damages which may be caused by stones 15 entering the slot during walking without skis.
It is within the scope of the invention to modify the shape, the dimensions and the proportions of the slots and of the friction plates or to make them of various materials or combination of materials, or to locate them in any fashion in the soles of the ski boots and on the skis.