SKI BOOT DESCRIPTION

The present invention relates to a ski boot having an improved structure. In particular, the present invention relates to a ski boot that is particularly suitable for use in various sporting activities, such as, for example, alpine skiing, ski mountaineering, telemark, free-ride, crosscountry skiing, and the like.

It is known that the structure of a ski boot generally comprises a shell, at least partially made of plastic material, and a sole fixedly connected to the shell, generally so as to form a substantially monolithic structure therewith.

It is likewise known how, over the course of the years, there has been the tendency to stiffen increasingly the shell and the sole of the ski boot, at times also using metal inserts so that the overall structure of the boot will be able to transmit the forces from the user's foot and leg to the ski efficiently and without any dispersion. This enables, in fact, a considerable increase in the control over the ski. On the other hand, a rigid and substantially undeformable shell and sole enable better support for the user's foot and leg, thus increasing comfort when skiing. The use of very rigid structures leads, however, to drawbacks of various types. For example, a rigid structure constitutes an obstacle to adequate bending of the knees by the user. To solve this type of drawbacks, numerous models of ski boots have been developed, provided with a cuff with flaps made of relatively soft material, designed to facilitate bending of the lower portion of the user's leg. An example of said type of ski boots is described in the patent No. US 4,078,322.

For use in very technical sporting activities, such as for example telemark, which require very accentuated bending of the knee and of the lower portion of the user's leg, ski boots are produced, provided with relatively flexible regions also in the shell and/or in the sole, approximately in a position corresponding to the user's forefoot. An example of said type of ski boots is described in the patent No. EP 647103. Finally, to improve comfort for the user when walking, ski boots are made, which are provided, in a position corresponding to the front portion of the shell and of the sole, or else in a position corresponding to the heel portion, with relatively flexible regions. Said flexible regions, in particular those regarding the sole, behave as a substantially rigid body during skiing. Two different examples of this type of ski boots are described in the patents Nos. US 4,571,858 and US 4,261,114.

Experience has, however, shown that, in ski boots of a known type, other drawbacks continue to exist. The relative rigidity of the sole and of the lower portion of the shell, close to the sole,

renders the ski boot similar to a substantially undeformable element located on the ski. During skiing, particularly in the phases of curving and/or in the case of a non-uniform ski run (for example, in the presence of humps or similar irregularities), the ski boot is not able to follow effectively the natural deformations of the ski. In such situations, this fact causes a reduction in the capacity of control over the ski on the part of the user. There may thus arise considerable critical situations, in the case where the skiing conditions are particularly demanding.

Furthermore, the rigidity of the sole counters the natural movements of the plantar arch of the user's foot, during the steps of bending/compression of the ski. This leads to the presence of torsional stresses at the level of the user's foot, which lie undoubtedly at the origin of a reduced comfort and possible fatigue.

Consequently, the main task of the present invention is to provide a ski boot that will enable the drawbacks referred to previously to be overcome.

In the framework of this task, one of the purposes of the present invention is to provide a ski boot that is able to follow the movements of the ski, in particular the movements of bending/compression of the ski.

Another purpose of the present invention is to provide a ski boot that will enable the natural movements of the plantar arch of the user's foot to be followed effectively.

Not the least important purpose of the present invention is to provide a ski boot that is relatively simple to industrialize and manufacture, at contained and economically competitive costs.

The above task and purposes, as well as other purposes that will appear evident from the ensuing description and the attached drawings, are achieved, according to the invention, by a ski boot comprising a shell designed to house the user's foot and a sole, fixedly connected to said shell and positioned underneath it. Said sole comprises a front portion, approximately in a position corresponding to the user's forefoot, a rear portion, in a position corresponding to the heel of the user, and a median portion located between said front portion and said rear portion, approximately in a position corresponding to the plantar arch of the user. The ski boot according to the invention is characterized in that said median portion of the sole comprises at least one first flexible region, designed to bend reversibly, during use of the boot mounted on a ski.

Further characteristics and advantages of the sole for a ski boot according to the present invention may be better appreciated with reference to the description provided in what follows and to the annexed plate of drawings, which is provided purely by way of illustrative and non-

limiting example and in which:

- Figure 1 is a schematic representation of a partial longitudinal cross sectional view of the ski boot according to the present invention, in a preferred embodiment; and

- Figure 2 is a view from beneath of the sole of a ski boot according to the present invention, in the embodiment of Figure 1; and

- Figure 3 is a view from beneath of the sole of a ski boot according to the present invention, in another preferred embodiment; and

- Figure 4 is a view from beneath of the sole of a ski boot according to the present invention, in another preferred embodiment; and

- Figure 5 is a view from beneath of the sole of a ski boot according to the present invention, in a further preferred embodiment.

With reference to the above figures, the ski boot 1 according to the present invention comprises a shell 2, designed to house the user's foot at least partially. The shell 2 is preferably made of plastic material and has a substantially rigid structure, particularly in a position corresponding to the forefoot and the heel of the user. The ski boot 1 according to the present invention, also comprises a sole 3, fixedly connected to the shell 2, preferably so as to form a monolithic structure therewith. The sole 3 is positioned underneath the shell 2. It comprises a front portion 4, approximately in a position corresponding to the user's forefoot, a rear portion 5, approximately in a position corresponding to the user's heel, and a median portion 6, located between the front portion 4 and the rear portion 5, approximately in a position corresponding to the plantar arch of the user.

The peculiarity of the ski boot 1 , according to the present invention, consists in the fact that the median portion 6 comprises at least one first flexible region 7, designed to bend reversibly and preferably in a pre-defined way, during use of the boot, mounted on a ski (not shown). Advantageously, the first flexible region 7 is made so as to be able to bend in an anisotropic way, in a pre-defined direction and sense. Preferably, the first flexible region 7 bends according to a direction substantially orthogonal to the resting plane 25 of the user's foot. In particular, during a phase of thrust, i.e., of transmission of forces from the boot to the ski, as occurs during entry into a curve, the first flexible region 7 bends in the direction of the ski (or of the terrain), as indicated by the arrow 8. In a similar way, in a phase of counterthrust, i.e., of transmission of forces from the ski to the boot, as occurs during exit from a curve, the first flexible region 7 bends in the direction opposite to the ski (or to the terrain), basically in the direction indicated by the arrow 9. The first flexible region 7 is thus able to bend with direction

and sense that correspond, in the different phases of skiing, to the direction and sense of the lines of force transmitted between the user's leg and the ski.

In a preferred embodiment, the first flexible region 7 comprises one or more corrugations 10 of the sole 3, each of which extends along a pre-defined directrix. As illustrated in Figures 2-5, the corrugations 10 can develop along directrices that are parallel to or intersect one another, according to the requirements. For example, in the embodiment of Figure 2, the corrugations 10 extend along parallel directrices 11, having a direction substantially perpendicular to the longitudinal axis 12 of the sole 3. Instead, in the embodiment of Figure 3, the corrugations 10 extend along parallel directrices 13, having a direction substantially parallel to the longitudinal axis 12. Obviously, the different types of corrugations can coexist, within the first flexible region 7, as illustrated in the embodiments of Figures 4 and 5. Furthermore, as is, for example, illustrated in the embodiment of Figure 5, the corrugations 10 can develop along directrices 14 and 15, forming pre-defined angles 16 and 17 with the longitudinal axis 12. Obviously, the angles 16 and 17 can vary according to the requirements.

Preferably, as illustrated in Figure 1, the corrugations 10 are formed by a succession of reliefs and grooves having a transverse profile that reproduces, at least partially, a waveform of a periodic type. The waveform characterizing the aforementioned transverse profile can be chosen according to the requirements. For example, a profile with a waveform of a triangular type, as illustrated in Figure 1 , or else square, circular, or sinusoidal (not illustrated) can ensure a greater flexibility of the flexible portion 7, whereas a profile with a semi-triangular, semi- square, semi-circular waveform (not illustrated) ensures a greater rigidity thereof. A modulation of the degree of flexibility of the first flexible region 7 is obtained, not only by varying the geometrical disposition of the corrugations 10 but also by appropriately calculating the height H of the corrugations 10 and/or the corresponding radius of curvature R. The effective degree of bending of the first flexible region 7 can be modulated also by varying the overall thickness K of the sole 3. In particular, calculating appropriately the latter parameter it is possible to cause the first flexible region 7 to come to bear upon the ski, during the movement of bending downwards. This is particularly advantageous because the ski itself behaves, in this case, as a limiter designed to prevent over-extensions of the first flexible region 7, which, with time, could damage the structure thereof. It is then evident how the first flexible region 7 may be made in such a way as to adapt the dynamic behaviour of the ski boot better to the type of use for which the boot is designed. According to a particularly advantageous embodiment, illustrated in Figure 2, the shell 2

comprises one or more second flexible regions 20 that extend from the first flexible region 7, approximately in a position corresponding to the plantar arch of the user. Advantageously, the second flexible regions 20 comprise one or more second corrugations 21, which constitute the prolongation of one or more of the first corrugations 10 of the first flexible region 7. In particular, the second corrugations 21 extend along directrices 11 parallel to one another and having a direction substantially perpendicular to the longitudinal axis 12 of the sole 3. This solution is particularly advantageous, given that it enables selective modulation of the rigidity of the shell 3, particularly in the proximity of the first flexible portion 7. The second flexible regions 20 can bend together with the first flexible region 7 during use of the boot 1 mounted on a ski. The median portion of the shell 3 is then able to follow the movements of the sole 3, so increasing the effectiveness of the movements of adaptation of the boot to the thrust and counterthrust that are transmitted between the user's leg and the ski.

As the corrugations 10 of the first flexible region 7, also the second corrugations 21 may extend along directrices 13-15, which are not perpendicular to the longitudinal axis 12. For example, in the first flexible region 7 is realised according to the embodiments shown in Fig. 3- 5, the second corrugations 21 will extend along directrices 13-15 that are parallel or angled with respect to the longitudinal axis 12, so as constitute, at least in this latter case, the natural prolongation of the first corrugations 10.

It has in practice been seen that the ski boot according to the present invention enables the problems of the known art to be solved and presents numerous advantages with respect thereto. In particular, thanks to the presence of the first region 7, the boot proves to be no longer an undeformable element but is able to change its own configuration according to the direction of the forces transmitted between the user and the ski. The boot can follow the bending movements of compression/extension of the ski, in particular during the steps of curving and/or in the presence of a non-uniform ski run. At the same time, also the natural movements of the plantar arch are followed. On the other hand, the fact that the flexible regions 7 and 20 are set in a position corresponding to the median portion of the sole and of the shell enables in any case an effective and non-dispersive transmission of the forces from the user's foot/leg to the ski. As compared to the solutions of the prior art, the ski boot, according to the invention, thus presents the major advantage of ensuring an effective transmission of the force between the user and the ski and, simultaneously, of modifying its own configuration according to the modalities with which this transmission of the forces occurs. This results in a greater control over the ski during all the phases of skiing and in an improved comfort for the

user.

The ski boot according to the present invention does not present particular aspects of difficulty from the production standpoint. It can in fact be conveniently manufactured by means of the known techniques of moulding of plastic materials. Consequently, it has proven relatively simple to industrialize at contained and economically competitive costs.