Biomechanical ski-boot

Abstract: By embedding blocks of resilient material, where necessary reinforced, in the toe-piece and heel of the sole of a ski-boot, so that their upper surfaces make contact with a counter-sole made of rigid material internally covering the bottom of the shell and with the bottom of the wedge contained inside the shell, the responsiveness and the accuracy of transmission of the movements from the limb and foot of the skier to the ski remain unaffected, while the muscular fatigue affecting the limbs and back of the skier is substantially reduced.

Description: The present invention relates to ski-boots and more specifically to an improvement to the soles of these boots. It is well-known that modern ski-boots comprise a substantially rigid casing or shell with which a sole is associated at the bottom, while the top part is completed by a leg part which is normally hinged with the shell and shaped according to the different models (front entry, rear entry, etc.). The ski-boot is completed internally by a shoe which comfortably supports the skier's foot. The more recent types of ski-boots are furthermore equipped with devices for adjusting certain features which are important for ordinary or competitive use of the boot, such as for example adjustment of the lateral inclination of the boot (known as "canting"), the forward inclination of the leg-piece, the degree of bending of the said leg-piece, etc. One of the main problems associated with the ski-boot structure briefly described above is that of the responsiveness and accuracy of transmission of the movements from the leg and foot and from the joints (heels, knees, hips) of the skier to the ski via the boot and therefore ultimately via the sole of the said boot. Another equally important problem is that of the muscular fatigue affecting the limb of the skier in particular when the latter has to ski on a hard and not perfectly smooth surface. Until now, in the design of ski-boots, more attention has been paid to solving the first problem, with the result that ski-boots have been proposed and designed so as to offer an excellent if not exceptional competitive performance, but without adequate consideration being given to the comfort of the skier. In other cases, the entirely opposite approach has been adopted, with the design of ski-boots which are extremely comfortable but unsuitable for use even of a slightly competitive nature. European Patent Application No. 432793 discloses a ski-boot wherein the outsole is joined with the insole either through a rubber dampening plate (20), extending all over the entire upper surface of the sole, or through flexible metal strip (39,39') is interposed between the outsole (32,32') and the insole (2',2''). The metal strip is fixed to the insole (2',2'') by fixing means (41,41'), preferably rivets, inserted in holes (30,30') made in the insole. French Patent Application No.2663821 discloses an insole (4) in contact to an outsole (2) by means of cross-pieces (6,7) attached to the lower surface of the insole, each cross-piece resting on a respective dampening element (8,9) attached to the upper surface of the outsole. On the contrary, the aim of the present application is of reducing vibrations which are transmitted to the skier's foot from the sole of the ski-boot. Both the above mentioned prior art publications contain features appearing in the preamble of claim 1. The aim of the present invention is therefore to provide a boot in which the accuracy of transmission of the movements from the leg and foot of the skier to the ski is maintained and at the same time the fatigue affecting the skier's lower limb is reduced, in particular on hard and/or uneven surfaces. This aim is achieved in this ski-boot comprising a rigid shell with which is associated, a rigid countersole rigidly integral with the shell, said shell having first and second non rigid elements interposed between said sole and the countersole, comprising a separate toe part and a separate heel part connected to the bottom of the sole, characterized in that of said non rigid elements, each having a lower end surface and an upper end surface extending over at least most of a width of the sole, the first one is disposed in such a way that its lower end surface contacts the said toe part and the upper end surface contacts the said countersole whereas the second one is disposed in such a way that the lower end surface contacts the heel part and the upper end surface contacts the countersole so that both the toe part and the heel part from one side and the countersole on the other side are spaced from each other by said non rigid elements, the said elements passing through the sole and the said countersole abutting on the upper surface of said sole at all locations of the countersole except at locations at which said upper surfaces of said non rigid elements contact the countersole . The tests carried out with the ski-boot according to the present invention have demonstrated, on the one hand, that the responsiveness and accuracy of transmission of the movements from the skier's leg and foot to the ski is maintained at an excellent level, compatible in particular with high-quality competition boots owing to the counter-sole made of rigid material, and, on the other hand, that there is a substantial reduction in the sensation of fatigue and pain affecting not only the lover limbs but also the back of the skier when the ski is used on hard and not perfectly smooth surfaces. As a result of the system of blocks, the vibrations of the sole are reduced substantially, enabling the skier to perform more precisely and efficiently the athletic movement of reversal of the edges of the skis. The present invention is illustrated, with regard to its two preferred embodiments, in the description with follows with reference to the accompanying drawings provided by way of a non-limiting example. In the accompanying drawings: Figure 1 is plan view of the bottom of the ski-boot according to a first embodiment of the present invention; Figures 2, 3 and 4 are sectional views along the planes II-II, III-III and IV-IV, respectively, of Fig. 1; Figures 5, 6, 7 and 8 are views, corresponding to those of Figures 1-4, of a second embodiment of the invention. Figures 1 to 4 illustrate in particular a portion of the rigid shell 20 of the boot, on the bottom 22 of which a conventional wedge 24 rests internally via an insert or counter-sole 25 which is made of aluminium or wood or compound plastic materials, is light and at the same time is rigidly integral with the shell 20 which is injected onto it and which has the function of increasing the responsiveness and accuracy of reaction during transmission of the movements from the skier's limb to the ski via the boot. The sole of the boot consists in this case of two portions 26 and 28, the toe-piece and heel respectively, which are fixed externally to the bottom of the boot in the conventional manner, for example by means of screws, the circles 30 of which in Figure 1 represent the outlines. As shown in broken lines in Fig. 1 and in the cross-sections of Figures 2 to 4, the two elements 33 and 36 made from a resilient material, such as polybutadiene rubber for example, are anchored in the respective toe and heel parts 26 and 28 forming the sole of the boot. In particular in this embodiment the elements 33 and 36 extend through the bottom 22 of the shell 20 of the boot until they come into contact with the rigid insert or counter-sole 25. Since the movements imparted by means of the skier's legs and feet to the ski are transmitted via the toe-piece and heel of the boot it is obvious that these movements pass through the elements or blocks 33 and 36. Without affecting the accuracy and responsiveness of the transmission of the movements in question, the result obtained is a substantial reduction in the sensation of fatigue (which may even take the form of actual pain) experienced when a boot with a high degree of accuracy and responsiveness in the transmission of movements (i.e. a boot of the type suitable and designed for competition) is used on a hard snowy and not perfectly flat surface. When the elements or blocks 33 and 36 have large dimensions, namely form a portion not smaller than the volume of the toe-piece and heel of the sole, it is envisaged, in order to obtain greater strength and wear as well as greater rigidity (responsible for the responsiveness and accuracy of transmission of the movements), to reinforce the blocks themselves for example using polyester coninjected with polybutadiene rubber or by including reinforcing fibres or the like. The embodiment of Figures 5 to 8 consists of a variation with respect to that shown in Figures 1 to 4, in which the block or resilient element 44 passes not only through the bottom 22 of the shell 20, but also the rigid insert 25 until it makes superficial contact with the bottom of the wedge 24. The invention has been described with regard to two of its preferred embodiments, but it remains understood that conceptually and mechanically equivalent modifications and variations are possible and may be envisaged without departing from the scope of the claims.

Claims: A ski-boot comprising a rigid shell (20) with which a sole is associated, a rigid countersole (25) rigidly integral with the shell (20), said shell (20) having first (33) and second (36,44) non rigid elements interposed between said sole and the countersole, comprising a separate toe part (26) and a separate heel part (28) connected to the bottom of the sole, characterized in that of said non rigid elements, each having a lower end surface and an upper end surface extending over at least most of a width of the sole, the first one (33) is disposed in such a way that its lower end surface contacts the said toe part (26) and the upper end surface contacts the said countersole (25) whereas the second one (36, 44) is disposed in such a way that the lower end surface contacts the heel part (28) and the upper end surface contacts the countersole (25) so that both the toe part (26) and the heel part (28) from one side and the countersole on the other side are spaced from each other by said non rigid elements, said elements passing through the sole and said countersole (25) abutting on the upper surface of said sole at all locations of the countersole except at locations at which said upper surfaces of said non rigid elements contact the countersole . Ski-boot according to Claim 1, characterized in that said non-rigid material is a resilient material incorporating, where necessary, stiffening elements. Ski-boot according to Claim 2, characterized in that said resilient material is polybutadiene, unmodified polyurethane or an expanded or semi-rigid polymer. Ski-boot according to Claim 2 or 3, characterized in that said stiffening material, where used, is a thermoplastic or thermo-setting material mixed with said resilient material. Ski-boot according to Claim 2 or 3, characterized in that said stiffening material consists of linear elements and fibres, such as carbon fibres, kevlar, etc. Ski-boot according to Claim 1 in combination with one of Claims 2 to 5, characterized in that said non rigid or resilient elements (33, 36, 44) made of resilient material consist of blocks which are coinjected or in any case anchored or interposed in each of them. Ski-boot according to Claim 6, characterized in that a conventional wedge (24) is arranged inside said boot and said blocks pass through the bottom (22) of the shell (20), coming into contact with the lower surface of said wedge (24). Ski-boot according to Claim 7, characterized in that said blocks are integral with a counter-sole (25) made of rigid material which covers internally said bottom (22) of said shell (20). Ski-boot according to Claim 8, characterized in that said counter-sole (25) is made of aluminium, wood or compound plastic materials.

Inventors: GOGGIA GIUSEPPE, LORATI PIERLUIGI, MAREGA ANTONELLO, GOGGIA, GIUSEPPE, LORATI, PIERLUIGI, MAREGA, ANTONELLO
Applicants: TECNICA SPA
Application year: 1993
Main classification: A43B1
IPC codes: A43B5, A43B13