Ski boot with improved lateral support
BACKGROUND OF THE INVENTION 
     The present invention relates to a ski boot with improved lateral support. 
     The problem of transmitting the efforts of the foot to the ski in an efficient manner, so as to achieve optimum control of said ski, is nowadays strongly felt for ski boots. 
     In this regard, some solutions are known, related or aimed directly at these problems. Among them, mention should be made of U.S. Pat. No. 3,545,103 which discloses a ski boot closure device comprising a metallic lateral plate that laterally surrounds the outer part of the foot and with which a cuff is rotatably associated. 
     Although this plate stiffens the boot to a given extent, it nonetheless does not provide optimum transmission of the efforts from the foot to the ski. In current skiing technique, the ski is in fact controlled by the inner part of the leg and of the foot, and this is therefore the part of the ski boot that is most intensely stressed during skiing and that transmits the efforts. 
     The placement of the plate on the outer side in the prior patent is therefore not effective for precise ski control. 
     Italian patent no. 1,051,302 discloses a ski boot made of plastics which is substantially constituted by two shells that mutually overlap along lateral joining lines and are kept in this closed position by fastening means. 
     This solution, which has the purpose of providing a method for manufacturing the boot in a mold without back drafts, entails the presence of parts that allow to adapt it to devices for binding to the ski, as well as a framework formed by thick and rigid ridges and by thin flat portions that connect said ridges. 
     Although it partially solves the described technical problem, as the ridges affect both the outer side and the inner side of the boot, even this solution does not allow to achieve optimum transmission of efforts from the foot to the ski, because in controlling the ski, the efforts are discharged approximately at the region of the plantar arch. In the solution illustrated in the patent, this region is not affected by the rigid ridges but by the thin flat portions. 
     Furthermore, the arrangement and shape of the ridges in any case causes the boot to be subject to slight deformations during sports practice that help to reduce the optimum transmission of efforts to the ski. 
     Italian Patent application no. 82513 A/87, filed on Feb. 25, 1987 in the name of this same Applicant discloses a ski boot which is constituted by a semirigid innerboot with which it is possible to associate at least one first rigid element, which partially surrounds the lower and lateral regions of the semirigid innerboot. Two second rigid elements are arranged at the sides of the semirigid innerboot and are rotatably associated with the first rigid element and articulated to it. 
     This solution, too, despite partially overcoming the drawbacks described above, is not optimum as regards effort transmission, because the presence of articulations does not allow, in any case, highly efficient transmission of efforts for optimum ski control. In fact, plays generate at the articulation between the first element and the second rigid elements, also due to wear and deformations, and tend to reduce the efficiency of the transmission. 
     International Patent WO 92/16120 claiming an Austrian priority, no. A 631/91 dated Mar. 21, 1991, discloses a ski boot which comprises a support that can be fixed to the leg above the ankle, is connected to the sole by means of a bar, and is shaped like a stencil that can be fixed and acts together with at least one part of the shell. The stencil-like support is connected to the bar, preferably at a level located between two closed portions of said stencil-like support, by means of a bracket that approximately comprises half of the circumference of the leg. 
     Even this solution is not optimum as regards the transmission of efforts directly to the ski, because it is again constituted by a plurality of elements that can be coupled to each other, to the shell and to the quarter of the boot. 
     It is also noted that the bar is laterally provided with two arms, the lower parts thereof are associated at the heel region of the shell. 
     This solution is not optimum for the transmission of efforts to the ski, because this arrangement produces moments that can open out the curve or cause a self rotation in extreme circumstances. 
     As regards the described technical problem, this same Applicant filed an Italian application, no. 82601 A/90, on Jul. 23, 1990, claiming a quarter associated with the shell, and at least one slot being formed on said quarter at the lateral regions. The slot has the same angle, or a different angle, with respect to at least one guide formed on the shell, and at least one slider is slidingly associated between the slot and the guide. 
     Even this solution has drawbacks due to the fact that the quarter is laterally pivoted to the shell by means of studs or by means of a crosspiece arrangeable at a seat formed transversely and below the sole. 
     On one hand, in fact, the quarter does not have particular lateral support characteristics considering the material of which it is usually made, and on the other hand its tilting does not allow optimum transmission of the efforts to the ski, as the function related to the variation of the inclination that can be achieved for the quarter is privileged. 
     SUMMARY OF THE INVENTION 
     The aim of the present invention is to solve the described technical problems, eliminating the drawbacks of the above mentioned prior art and thus providing an invention that allows to achieve, for the boot, optimum transmission of the efforts from the leg to the ski and thus precise control of said ski, substantially in the absence of moments that can open out the curve or cause a self rotation. 
     Within the scope of the above aim, another important object is to provide an invention that ensures highly efficient transmission of efforts for optimum and immediate ski control. 
     Another important object is to provide an invention that associates with the preceding characteristics that of improving effort distribution, balancing the efforts between the leg and the foot. 
     Another object is to provide an invention that allows a distribution of the efforts that facilitates the vertical release of the toe and of the binding in safe conditions. 
     Another object is to provide an invention that has low manufacturing costs and also increases the aesthetic features of the boot. 
     This aim, these objects and others which will become apparent hereinafter are achieved by a ski boot with improved lateral support, comprising at least one quarter associated with a shell, characterized in that it comprises at least one rigid element which is monolithic, or formed integrally, with said shell and at least partially affects the inner side of the foot and leg and the plantar arch. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further characteristics and advantages of the invention will become apparent from the detailed description of some detailed but not exclusive embodiments, illustrated only by way of non-limitative example in the accompanying drawings, wherein: 
     FIG. 1 is a side view of the ski boot with the rigid element applied thereto; 
     FIG. 2 is a second side view of the ski boot of FIG. 1; 
     FIG. 3 is a perspective view of the rigid element alone; 
     FIG. 4 is a view, similar to the preceding one, of the rigid element according to a further aspect of the invention; 
     FIG. 5 is a view, similar to FIG. 1, of a further embodiment of the invention; 
     FIG. 6 is a sectional view, taken along the plane VI--VI of FIG. 5; 
     FIG. 7 is a view, similar to FIG. 1, of another embodiment of the invention; 
     FIG. 8 is a view, similar to FIG. 2, of the ski boot shown in the preceding figure; 
     FIG. 9 is a rear perspective view of the rigid element according to still a further aspect of the invention; 
     FIG. 10 is another sectional view, taken along the plane X--X of FIG. 7. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the above figures, the reference numeral 1 designates the ski boot, which is constituted by at least one quarter 4 associated to a shell 2, by means of adapted studs 3. 
     The boot is also constituted by at least one rigid element, designated by the reference numeral 5, that is formed monolithically. The rigid element 5 has no moving components and is preferably located at the inner side 6 of the foot. 
     The rigid element 5 also has a first flap 7 which is adjacent both to the shell 2 and to the quarter 4 at the inner side of the foot and at the inner side 8 of the leg. The first flap is fixed to the shell and to the quarter at the studs. 
     The first flap 7 is essentially L-shaped, and its first wing 9 runs approximately from the region in front of the heel to the metatarsal region. A C-shaped arm 10 is associated below said wing and is fixed at the plantar arch 11. As clearly visible in FIG. 1, the arm 10 extends beneath and along the plantar arch from a zone located below the malleolar region 17 of the shell 2, to a zone located below the metatarsal region thereof. 
     The second wing 12 in the first flap 7 advantageously protrudes beyond the upper perimetric edge 13 of the quarter 4, and surrounds it to the rear. The second wing 12 is connected to a second flap 15 by means of a first bridge 14. The second flap 15 affects the outer side 16 of the leg and is then fixed at the studs 3 at the end that lies approximately adjacent to the malleolar region 17. 
     The first and second flaps are also mutually connected by means of a second bridge 18 at the region overlying the heel 19. 
     The rigid monolithic element is advantageously arranged both on the inner side of the foot and on the outer side of the leg and, in view of the fact that it is rigidly fixed at the plantar arch, allows to achieve optimum ski control. The ski control in fact substantially occurs by means of the inner side of the foot and of the leg, and the transmission of efforts from these parts to the ski is discharged approximately at the plantar arch, which can thus be defined as the &#34;control center&#34; of the foot. 
     The structure and arrangement of the rigid element therefore allows to transmit forces in a precise and immediate manner, substantially without moments that can open out the curve or cause self rotation. The absence of articulations ensures the highly efficient transmission of efforts for optimum ski control. 
     Furthermore, the shape of the rigid element 5, which flares out from the bottom upward starting from the region of the plantar arch 11, improves effort distribution, balancing these efforts between the leg (substantially in the application of efforts in the rear region, as well as lateral efforts for control and edge grip) and the foot (substantially in the application of efforts in the front region to achieve tight curves and quick reversals). 
     It has thus been observed that the invention has achieved the intended aim and objects, furthermore obtaining an optimum rear support that also discharges backward efforts onto the load-bearing structure of the boot. 
     The shape of the rigid element 5 and the related effort distribution furthermore facilitate the vertical release of the toe unit of the binding in safe conditions, because the resting effort that acts on said rigid element is not discharged fully onto the heel, as usually occurs in the prior art, but a part of said effort produces an overturning moment beneath the sole, thus facilitating vertical release. 
     The ski boot according to the invention is naturally susceptible to numerous modifications and variations, all of which are within the scope of the same inventive concept. 
     Thus, for example, FIG. 4 illustrates a rigid element 105 which is constituted only by a first flap 107 the first wing 109 thereof is associated with the arm 110 in a downward region. The arm is fixed at the plantar arch region. 
     The first wing 109 and the second wing 112 of the first flap 107 thus affect the inner side of the foot and the inner side of the leg. 
     FIGS. 5 and 6 illustrate another embodiment of a boot 201 constituted by at least one quarter 204 associated with a shell 202. 
     Here also there is a rigid element 205 constituted by a first flap 207 which has a first wing 209 and a second wing 212 that respectively affect the inner side 206 of the foot and the inner side 208 of the leg. 
     Here also below the first wing 209 there is an arm 210 which is rigidly associated at the plantar arch 211. 
     The first flap 207 is also fixed to the shell 202 and to the quarter 204 by means of the studs 203. The second wing 212 is directly connected to the shell 202, and a lug 220 protrudes from the shell and can be arranged at a complementarily shaped opening 221 that is formed on the second wing 212, above the upper perimetric edge 213 of the quarter 204. 
     The second flap 215 is instead fixed to the shell 202 by means of the studs 203. 
     FIGS. 7 to 10 illustrate another embodiment of a ski boot 301 which is composed of at least one quarter 304 associated with a shell 302. 
     Here also there is a monolithic rigid element 305 which is constituted by a first essentially L-shaped flap 307 the first wing 309 thereof affecting the inner side 306 of the foot. An arm 310 is associated in a downward region with said wing and is fixed at the plantar arch 311. 
     A first arched, or curved, slot 322 is formed at the second wing 312, and its rotation center is arranged approximately at the axis of the studs 303. 
     The first slot 322 constitutes a guiding element for the rotation of the quarter 304, which has at least one adapted lug 320a which is rigidly coupled to, and protrudes externally from, the quarter 304 and slidingly engages the first slot 322; the lug 320a is thus suitable to limit the rotation of the quarter 304. 
     The tip of the second wing 312 that protrudes above the upper perimetric edge 313 of the quarter 304 is connected to a second flap 315, by means of a first bridge 314. The second flap 315 affects the inner side 308 of the leg and is fixed at the studs 303, at its loose end. 
     The connection between the second wing 312 of the first flap 307 and the second flap 315 occurs also by means of a second bridge 318 that lies above the malleolar region 317 and by means of a third bridge 323 which is arranged in a median region with respect to the first and second bridges. 
     A second arched slot 324 is formed at the second flap 315 as well. The slot center of rotation lies approximately at the axis of the stud 303, and the slot, too, acts as guiding element for the rotation of the quarter 304. This oscillation is limited by the presence of a lug 320b that protrudes outside the quarter 304 and engages the slot 324. 
     In the interspace between the ends of the first and second slots and the respective lugs it is possible to interpose an element, for example a plastic block, that has the required degree of elasticity and thus allows to change the forward or backward flexing of the quarter. 
     The inclination of the quarter can also be changed by interposing a spacer element, at the first bridge 314 and/or at the second bridge 318 and/or at the third bridge 323 and at the outer lateral surface of the quarter 304. The spacer element may have the desired thickness. 
     Naturally, the materials and the components that constitute the boot may be the most pertinent according the specific requirements.