Cross-Country Shoe

The present invention concerns a cross-country ski boot.

As described in particular in Patents N.degree.s FR-A-2 443 853, FR-A-2 387 062, and AT-368 368, cross-country ski boots are already well known in which the soles, made of a molded plastic material, have hollow and/or raised parts intended to cooperate with corresponding raised and/or hollow parts on the upper surface of a cross-country ski. One especially well-known ski boot has a sole equipped with a central longitudinal groove which cooperates with a longitudinal rib on the upper surface of the ski in order to provide lateral control of the boot when the skier's foot is spread out flat on the ski. By virtue of their design, the soles of cross-country boots of this kind make contact with the raised and/or hollow parts of the cross-country ski in circumscribed areas where the frictional forces are concentrated, and, in these circumscribed areas, the soles show a substantially-reduced resistance to wear. This wearing phenomenon is especially pronounced in the area providing support for the heel, which is alternately raised and lowered during cross-country skiing, and which thus comes into periodic contact with the ski.

The aim of the present invention is to solve these problems simply and effectively by increasing the resistance to wear of the heel of the boot, without changing the static stable positioning of the foot.

For this purpose, this cross-country ski boot comprises a sole made of a molded plastic material having a longitudinal groove by means of which, when the boot is flattened out on the ski, the sole covers a longitudinal rib placed on the upper surface of the ski, this sole being characterized by the fact that it comprises, at least in the area of its heel, a shaped rigid reinforcing element which molds itself to the transverse shape of the groove of the sole and which is embedded at least partially in the plastic material of the sole, and by the fact that this reinforcing element carries walking and/or wearresistance runners which are mounted on the surfaces of the element resting for support on the corresponding surfaces of the ski.

Several embodiments of the invention, provided as by way of example will be described below with reference to the attached drawings, in which:

FIG. 1 is an elevation view of a cross-country ski boot according to the invention;

FIG. 2 is a larger-scale vertical and transverse cross-section view along the line II--II in FIG. 1;

FIG. 3 is a perspective view taken from below of the cross-country ski boot according to FIG. 1;

FIG. 4 is an elevation view of the reinforcing element incorporated in the sole of the boot;

FIG. 5 is a plan view of the reinforcing element;

FIG. 6 is a bottom plan view of the reinforcing element;

FIG. 7 is a perspective, overhead view of the reinforcing element incorporated into the sole of the boot;

FIG. 8 is a bottom plan view of another embodiment of the reinforcing element; and

FIG. 9 is a perspective view of a boot according to the invention mounted on a shaped ski having an upper longitudinal rib, the heel of the boot being shown in a raised position.

The cross-country ski boot illustrated in the drawings comprises an upper 1 and a sole 2 made of a molded plastic material. This boot is designed to be attached by its forward tip to a cross-country ski 3 (FIG. 9) having a shaped, transverse section. This cross-country ski 3 has, more especially, on its upper surface a longitudinal rib 3a having, for example, the form of an isosceles trapezoid, which is delimited by a horizontal upper surface 3b making up the short base of the trapezoid rib and two sloping sides 3c, 3d. These two sides are, in turn, connected by horizontal rims 3e and 3f to the two lateral, vertical edges 3g and 3h of the ski 3. For its part, the sole 2 is shaped so as to have in its central portion a longitudinal groove 2a, trapezoidal in shape, which is designed to contain the longitudinal groove 3a of the ski 3 during cross-country skiing when the boot is extended so as to be flat on the ski. Thus, the longitudinal groove 2a delimits two lateral projecting parts 2b in the area of the heel 4.

In accordance with the invention, the sole 2 of the boot comprises, in its rear portion and at least in the area of the heel 4, a rigid reinforcing element 5 which is at least partially embedded in the plastic material making up the sole 2. More precisely, this reinforcing element 5, which is, advantageously, made of a molded rigid plastic material, comprises, as can be best seen in FIG. 2, a central core 5a totally embedded in the plastic material making up the sole 2 and extending above the groove 2a of this sole. This central core 5a is extended downward and outward on each longitudinal side by an internal sloping side 5b, in such a way that the core 5a and the sloping sides 5b together make up a transverse section profile in the shape of a trapezoid having a short upper base. Each sloping side 5b is, in turn, extended outward by a lower, horizontal wing 5c possessing slight width, which is, in turn, extended upward by an external wing 5d. As shown in FIG. 2, the sloping side 5b, the lower horizontal wing 5c, and the external wing 5d are mounted beneath the corresponding parts of identical shape on the sole 2a. However, in accordance with a variant, these parts could also be embedded in the plastic material of the sole 2 at these points. Each external wing 5d may be vertical, or it may, preferably, extend in sloping fashion from the inside outward and downward.

The central core 5a of the reinforcing element 5 may be continuous or, in accordance with a variant, it may be drilled with holes 5e spaced apart and aligned longitudinally, as may be better observed in FIGS. 5 to 7, these holes being filled with the plastic material of the sole 2 after molding, thereby improving the anchoring of the reinforcing element 5 in the sole 2. This anchoring may also be strengthened by means of points 5f produced in the molding which are spaced out longitudinally on the core 5a and extend upward. Each external wing 5d may also be provided with spaced anchoring points 5g arranged laterally along its upper edge.

The stiffness of the reinforcing element can be increased by providing, on the inner surfaces of the external wings 5d, stiffening ribs 5h extending vertically and spaced apart in the longitudinal direction.

The reinforcing element 5 carries, furthermore, on each longitudinal side, a wear-resistant and/or walking runner 6. This runner 6 fits the shape of the inner sloping side 5b and of the horizontal wing 5c beneath which it is attached. This attachment may, advantageously, be produced by gluing the runner 6 to the reinforcing element 5. The adhesion may be improved horizontal wings 5c with rough surfaces, for example ridges. Each runner 6 comprises an inner sloping wing 6a which is interposed between the sloping side 3c, 3d of the rib 3a of the ski 3 and the inner sloping side 5b of the reinforcing element 5, as well as a lower horizontal wing 6b extending between the lower horizontal wing 5c of the reinforcing element 5 and the corresponding horizontal rim 3e, 3f of the ski 3. Each runner 6 is attached to the reinforcing element 5 by any appropriate means, and this attachment may be strengthened by the anchoring of a rib 6c provided on the runner 6 (or the reinforcing element 5) along its edge, this rib being engaged in a groove 5i formed in the reinforcing element 5 (or the runner 6).

According to one variant, illustrated in FIG. 8, the grooves 5i of the reinforcing element 5 are replaced by a succession of recesses 5j, in which the corresponding points emanating from the runners 6 are inserted.

It may be observed, according to the preceding description, that the reinforcing element 5 is visible on the outside of the sole 2 on the two outer lateral sides of the two rear projections 2b extending downward, which are delimited by the central groove 2a in the area of the heel 4. The reinforcing element 5 may cover the rear extremity on each of the projections 2b. However, in the embodiment shown in the drawing, this rear extremity is covered by a portion 6d of the walking and/or wear-resistant runner 6 which runs upward and rearward.

The vertical, transverse section of the reinforcing element 5, which has an approximate W shape, as can be seen in FIG. 2, has a profile which decreases toward the front of the boot, that is, its height decreases progressively and this reinforcing element stops at about the middle of the sole 2, that is, at the beginning of the area of plantar support. The sole 2 is this subdivided into two parts, a flexible front part corresponding to area A in FIG. 1 and extending from the front end of the boot to the front end of the reinforcing element 5, and a rigid rear part B extending from the end of the reinforcing element 5 to the rear of the heel 4.

The reinforcing element 5 extends dissymmetrically in the longitudinal direction on both sides of the boot. FIGS. 1 to 7, which illustrate a left boot, show that the lower horizontal wing 5c and the corresponding outer wing 5d of the reinforcing element 5, which are located on the left side of the boot, i.e., on the outer side, are longer than the corresponding wings located on the right, or inner, side of the boot, and they extend substantially up to the beginning of the plantar support area, thus substantially over the half of the sole length corresponding to the rigid rear area B. On the other hand, the wings 5c, 5d of the reinforcing element 5, which are located on the inner side, i.e., on the right side of the left boot shown in FIGS. 1 to 7, extend substantially only over the length of the heel 4, that is, they stop before reaching the beginning of the arch. This construction results from the fact that, in an optimal median position of the foot on the ski 3, the boot 2 has a natural overhang which is more sizable on the outer edge, and from the fact that it would be necessary to fill in uselessly the area corresponding to the area of the arch, in order to produce a symmetrical reinforcing element 5 extending to the front of the foot.