TECHNICAL FIELD

The present invention relates to a heel for a women' s shoe with a high heel (i.e. a heel having a height greater than 5 cm) .

PRIOR ART

To increase the comfort of a women' s shoe with a high heel (i.e. to reduce the mechanical stresses to which the foot is subjected during walking with a women's shoe with a high heel) , it was proposed to make the heel vertically elastic (i.e. it was proposed to introduce a vertically directed elasticity into a heel) .

To make the heel vertically elastic it was proposed to divide the heel into an upper portion and a lower portion which can vertically move with respect to one another and to interpose between the two portions an elastic body that establishes a mechanical connection between the two portions themselves; the elastic body may be constituted by a metal spring (for example as described in patent application FR2235655A1) , or can be constituted by a "soft" element in plastic material (as for example described in patent application DE8316581U1) . However, this known solution has several drawbacks as it requires a number of additional components, leading to significant complication at the level of the production process and is applicable only to a limited type of heels .

The patent application FR1002135A1 describes a women's shoe provided with a heel wherein a plurality of horizontal slits which confer to the heel a certain vertical elasticity are formed; however, the solution described in this patent application does not allow to obtain an optimum walking comfort since the user clearly notices a "transverse instability" (i.e. perpendicular to the walking direction).

The patent applications CH212632A, GB238134A and FR1247874A1 describe a women's shoe provided with a heel, wherein, in the outer surface a plurality of horizontal grooves are formed which have a shallow depth (practically no more than one or two millimeters) and are "U" shaped to embrace the entire outer surface; however, the solutions described in these patent applications do not allow the heel to confer an adequate vertical elasticity.

DESCRIPTION OF THE INVENTION

The purpose of the present invention is to provide a heel for a women's shoe with a high heel that is free from the drawbacks described above and, at the same time, is easy and inexpensive to manufacture.

In accordance with the present invention, a heel for a women' s shoe with a high heel as defined in the appended claims is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the accompanying drawings, which illustrate certain non- limiting embodiments, wherein:

• Figure 1 schematically illustrates a women' s shoe with a high heel provided with a heel made in accordance with the present invention;

• Figures 2 and 3 are two different perspective views of the heel of Figure 1;

• Figures 4, 5 and 6 are respectively a right side view, a rear view, and a left side view of the heel of Figure 1;

• Figure 7 is a view on an enlarged scale of a detail of Figure 5 ;

• Figure 8 is a perspective view and vertical section of an alternative embodiment of the heel of Figure 1;

• Figure 9 is a view on an enlarged scale of a detail of Figure 8 made according to an alternative embodiment;

• Figure 10 is a perspective view of an alternative embodiment of the heel of Figure 1;

• Figure 11 is a perspective view of a further embodiment of the heel of Figure 1; • Figure 12 is a rear view of the heel of Figure 11;

• Figure 13 is a perspective and vertical section view of the heel of Figure 12;

• Figures 14 and 15 are two different perspective views of a further embodiment of the heel of Figure 1;

• Figure 16 is a view on an enlarged scale of a detail of Figure 15;

• Figure 17 is a perspective and vertical section view of a further embodiment of the heel of Figure 1;

• Figure 18 is a perspective view of a reinforcement pin of the heel of Figure 17;

• Figure 19 is a view on an enlarged scale of a detail of Figure 17;

• Figure 20 is a perspective view of a further embodiment of the heel of Figure 1;

• Figure 21 is a rear view of the heel of Figure 20;

• Figure 22 is a perspective and vertical section view of the heel of Figure 20;

• Figure 23 is a view on an enlarged scale of a detail of Figure 22;

• Figure 24 is a perspective and vertical section view of a variant of the heel of Figure 20;

• Figure 25 is a perspective view of a further embodiment of the heel of Figure 1;

• Figure ^' 26 is a rear view of the heel of Figure 25;

• Figure 27 is a perspective and vertical section view of the heel of Figure 25;

• Figure 28 is a view on an enlarged scale of a detail of Figure 27; and

• Figure 29 schematically illustrates a different women's shoe with a high heel provided with a heel obtained in accordance with the present invention.

PREFERRED EMBODIMENT OF THE INVENTION

In Figure 1, number 1 indicates as a whole a high heel women's shoe provided with a heel 2. Preferably, the heel 2 has a height greater than 5 cm. According to that shown in Figures 2 and 3 , the heel 2 comprises a main structure 3 with an oblong shape which extends along a vertical axis 4. The main structure 3 in correspondence with a lower base 5 is adapted to rest on the ground and in correspondence of an upper base 6 opposite to the lower base 5 is adapted to be fitted to a sole 7 of the shoe 1. - .

According to that shown in. Figures 2-7, the main heel structure 3 comprises two slits 8 which are horizontally- oriented (i.e. are perpendicular to the vertical axis 4) and are arranged vertically offset (i.e. at a certain vertical distance from one another) . Each slit 8 extends from side to side through the main structure 3 along a longitudinal direction 9 (i.e. parallel to the walking direction), and is blind along a transverse direction 10 (i.e. perpendicular to the walking direction and therefore to the longitudinal direction 9) starting from an inner portion of the main structure 3 and ending in correspondence of a side 11 of the main structure 3. Furthermore, the main heel structure 3 comprises two slits 12 which are horizontally oriented (i.e. are perpendicular to the vertical axis 4) and are arranged vertically offset (i.e. at a certain vertical distance from one another) . Each slit 12 extends from side to side through the main structure 3 along the longitudinal direction 9, and is blind along the transverse direction 10 perpendicular to the longitudinal direction 9 starting from an inner portion of the main structure 3 and ending in correspondence of a side 13 of the main structure 3 opposite to the side 11.

Preferably, the slits 8 are vertically alternated with the slits 12, i.e. a slit 8 is vertically followed and/or preceded by a slit 12. In the embodiment shown in Figures 1-7, two slits 8 to two slits 12 vertically alternated to one another are provided; according to different embodiments the number of slits 8 and/or 12 can be different (for example there may be only one slit 8 and only one slit 12, only one slit 8 and two slits 12 may be present, two slits 8 and three slits 12 may be present, three slits 8 and three slits 12 may be present ... ) .

According to a preferred embodiment, each slit 8 and 12 involve along the transverse direction 10 more than half of the main structure 3.

The slits 8 and 12 reduce the vertical stiffness of the main structure 3 and therefore give the main structure 3 a vertical elasticity. Obviously the number and the size of the slits 8 and 12 must be chosen as a compromise between structural strength (which cannot be too little) and the deformation capacity (i.e. the elasticity). By way of example, the thickness of the slits 8 and 12 is generally between 0.5 and 4 mm. Thanks to the presence of the slits 8 and 12, the main structure 3 of the heel 2 acts integrally as a compression spring so that if the vertical load exceeds a limit value, as can occur during walking, the "coils" of the "spring" are vertically compacted one upon the other preserving the main structure 3 from breaking. The pattern of the slits 8 and 12 is important in order to avoid (or at least restrict) the lateral deflection of the main structure 3 of the heel 2. Generally, an even total number of slits 8 and 12 (i.e. a symmetrical pattern with respect to the longitudinal plane, i.e. parallel to the longitudinal direction 9, of the main structure 3) is preferred as it avoids the onset of unwanted spurious bending.

The main structure 3 of the heel 2 can be made of many materials. By way of example, the main structure 3 of the heel 2 can be made of plastic material (ABS or a thermoplastic technopolymer eventually loaded with glass fibers) that is normally injection molded already in the final, shape, or the main structure 3 of the heel 2 can be made of metallic material (typically aluminum for its lightness) that - is normally solid machined by removal of material.

Depending on the material used to obtain the main structure 3 of the heel 2, to further increase the structural strength of the main structure 3 to transverse loads (i.e. directed along the transverse direction 10) it is possible to provide a reinforcement pin 14 (shown in Figure 8) that is made of a highly resistant material (for example steel) and is inserted inside the main structure 3 wherein it also fulfills the function of supporting the heel layer. Preferably, the reinforcement pin 14 is used when the main structure 3 of the heel 2 is made of low resistance plastic material.

According to the embodiment shown in Figure 8, the heel 2 comprises the reinforcement pin 14, which has a cylindrical shape, extending coaxially with the vertical axis 4, and is inserted inside a cylindrical seat 15 which is centrally obtained in the main structure 3. According to a preferred embodiment, the reinforcement pin 14 is integral, i.e. rigidly fitted (e.g. glued) , to a lower portion 16 of the main structure 3 arranged under the slits 8 and 12 and is slidably mounted with respect to an upper portion 17 of the main structure 3 arranged above the slits 8 and 12.

Preferably, in a central portion 18 of the main structure 3 arranged in correspondence of the slits 8 and 12 (i.e. arranged between the lower portion 16 and the upper portion 17 of the main structure 3) the reinforcement pin 14 has an external dimension smaller than the inner dimension of the seat 15 so as to avoid touching the wall of the seat 15. In particular, in correspondence of the central portion 18 of the main structure 3 the reinforcement pin 14 locally presents a reduction of the outer diameter.

According to the embodiment shown in Figure 9, in correspondence of the upper portion 17 of the main structure 3 the seat 15 is internally lined with an antifriction bushing 19 which externally is integral (e.g. by gluing) with the main structure 3 and internally houses in a sliding manner the reinforcement pin 14. The presence of the antifriction bushing 19 allows to ensure a better sliding of the reinforcement pin 14 with respect to the upper portion 17 of the main structure 3 even in the presence of temporary deformations of the upper portion 17 (that are possible as a result of mechanical stresses generated by walking) .

According to the embodiment shown in Figures 10 and 12, inside the main structure 3 each slit 8 or 12 ends with a cylindrical surface that is arranged parallel to the longitudinal direction 9; said cylindrical surface allows to avoid the presence of sharp edges inside the slit 8 or 12 thereby improving the fatigue strength. According to the variant shown in Figure 10, in each slit 8 or 12 the cylindrical surface has a diameter that is larger than the vertical dimension of the slit 8 - or 12; and this solution is usable if the slits 8 and 12 are obtained by machining from solid with a tool which provides material removal . According to the variant shown in Figure 12, in each slit 8 or 12 the cylindrical surface has a diameter equal to the vertical dimension of the slit 8 or 12; this solution is preferable if the slits 8 and 12 are directly obtained by way of an injection molding of the main structure 3 since it avoids the formation of undercuts.

According to the embodiment shown in Figures 11-13, only one slit 8 and only one slit 12 are provided, and the reinforcement pin 14 is provided slidably coupled to an antifriction bushing 19 which externally is integral with the main structure 3 in correspondence to the upper portion 17 of the main structure 3.

According to the embodiment shown in Figures 14-16, the main structure 3 comprises a through hole 20, which extends from side to side through the main structure 3 along the longitudinal direction 10 and is arranged in a central position in correspondence of the slits 8 and 12 (i.e. in correspondence of the central portion 18 of the main structure 3) . Preferably, the through hole 20 has an elongated cross section having the larger dimension oriented vertically (i.e. parallel to the vertical axis 4) .

The through hole 20 vertically divides the main structure 3 into two half-structures 3a and 3b (or into two columns 3a and 3b) which are parallel to each other and face each other. According to a preferred embodiment, each half-structure 3a and 3b comprises at least one slit 8 and at least one slit 12, and in one half-structure 3a/3b the slit 8 is vertically- aligned with the slit 12 of the other half-structure 3b/3a and the slit 12 is vertically aligned with the slit 8 of the other half-structure 3b/3a.

In the embodiment shown in Figures 14-16, it is possible to use' ah odd number of slits 8 and 12, as the alternation of slits 8 and 12 into two half-structures 3a and 3b otherwise confers to the main structure 3 as a whole an adequate symmetry with respect to a longitudinal plane (i.e. a plane parallel to the longitudinal direction 9) . It is important to note that the transverse stresses (i.e. directed along the transverse axis 10) tend to open the slits 8 and 12 of one half-structure 3a/3b but to close the slits 8 and 12 of the other half-structure 3b/3a, which by compacting, ensure an adequate mechanical seal; instead the longitudinal stresses (i.e. directed along the longitudinal direction 9) are supported by the vertical compaction of the coils of the half- structure 3a or 3b subject to compression.

The material used for the embodiment shown in Figures 14- 16 is preferably a material of the metal type which allows to obtain the sufficient mechanical strength even in the presence of very reduced transverse thicknesses .

According to a possible embodiment, at least part of the slits 8 and 12 (i.e. all the slits 8 and 12 or only some of the slits 8 and 12) can be filled with the viscoelastic material (or a material that exhibits an intermediate rheological behavior comprised between "purely viscous materials" and "elastic materials") to give a damping effect favoring comfortable walking.

According to a further embodiment each slit 8 or 12 ends with a cylindrical surface that is arranged parallel to the longitudinal direction 9, with . a diameter preferably greater than the vertical dimension of the slit 8 or 12.

In ^' the embodiment shown in Figures 17-19, the slits 8 and 12 (which confer a vertical elasticity) are transferred by the main structure 3 of the heel 2 to the reinforcement pin 1 . In this embodiment, the reinforcement pin 14 comprises an upper portion 21 that is integral (for example by gluing or mechanical coupling) to the upper portion 17 of the main structure 3, a lower portion 22 that is integral (for example by gluing or mechanical coupling) to the lower portion 16 of the main structure 3, and an intermediate portion 23, that connects without gaps, the lower portion 22 to the upper portion 21 and has a vertical elasticity thanks to the presence of the slits 8 and 12. The intermediate portion 23 of the reinforcement pin 14 comprises the slits 8 and 12, which confer a vertical elasticity to the intermediate portion 23 and have the structural characteristics described above.

In essence, in the embodiment shown in Figures 17-19 the reinforcement pin 14 comprises the upper portion 21 which is mechanically connected (in particular integral to) the upper portion 17 of the main structure 3, the lower portion 22 which is integral to the lower portion 16 of the main structure 3, and elastic means which present a vertical elasticity and are coupled to the reinforcement pin 14 to connect with a vertical elasticity the upper portion 17 of the main structure 3 to the lower portion 16 of the main structure 3. In this embodiment, the upper portion 17 of the main structure 3 is integral to the upper portion 21 of the reinforcement pin 14, and the reinforcement pin 14 comprises the intermediate portion 23 which connects without gaps, the lower portion 22 to the upper portion 21 and integrates in its inside the elastic means. Said elastic means are constituted by the slits 8 and 12 which are formed in the intermediate portion 23 of the reinforcement pin 14.

When the reinforcement pin 14 is used, the main structure 3 can be made of traditional plastic material (e.g. ABS) , while the reinforcement pin 14 can be made of special steel.

In the heel 2 so far described, in its various embodiments the damping effect is therefore obtained by structurally unloading the main structure 3 (or, alternatively, the reinforcement pin 14) by way of the slits 8 and 12 which reduce the vertical stiffness amplifying at the same time the possibilities of movement.

In alternative embodiments shown in Figures 20-24, the reinforcement pin 14 comprises the upper portion 21 which is mechanically connected (in particular in a sliding manner) to the upper portion 17 of the main structure 3, the lower portion 22 that is integral to the lower portion 16 of the main structure 3, and elastic means which present a vertical elasticity and are coupled to the reinforcement pin 14 to connect with a vertical elasticity - the upper portion 17 of main structure 3 to the lower portion 16 of the main structure 3. In these embodiments, the upper portion 17 of the main structure 3 is vertically slidable with respect to the upper portion 21 of the reinforcement pin 14, and the elastic "means are constituted by at least one spring 24 (preferably, but not necessarily, a disk spring) which is interposed between the reinforcement pin 14 and an abutment wall 25 of the upper portion 17 of the main structure 3. It is important to note that by changing the number of springs 24 used, with an equally applied maximum force, the damping effect is modified by increasing or decreasing the vertical displacement of the heel 2.

Preferably, the abutment wall 25 of the upper portion 17 of the main structure 3 is constituted by a metal assembly bushing 26 which is integral to the upper portion 17 and is placed immediately below the insole assembly. A fixing plate 27 is normally provided which is locked at the top of the reinforcement pin 14, leaning against the assembly bushing 26, and prevents the reinforcement pin 14 from sliding off and rotating upon. For example, the fixing plate 27 is locked at the top of the reinforcement pin 14 by means of a screw (not shown) which engages a threaded hole 28 formed through the upper portion 21 of the reinforcement pin 14.

According to a preferred embodiment, the spring 24 is compressed between the abutment wall 25 of the upper portion 17 of the main structure 3 and an annular shoulder 29 of the reinforcement pin 14; said annular shoulder 29 is obtained by way of tapering (thinning) of the reinforcement pin head 14.

According to a preferred embodiment, in correspondence to the upper portion 17 of the main structure 3 the seat 15 is internally lined by at least an antifriction bushing 19 which externally is integral to the main structure 3 and internally houses in a sliding manner the reinforcement pin 14.

In the embodiment shown in Figures 20-24, the lower portion 16 of the main structure 3 is separated from the upper portion 17 of the main structure 3 by way of a through cut 30 which completely separates the two portions 16 and 17 without any point of contact between the two portions 16 and 17 themselves (exactly as also happens in the embodiment shown in Figures 17-19) .

In the embodiments shown in Figures 20-23, the reinforcement pin 14 has two diameter variations so as to ensure the necessary structural strength consistently with the final thinning of the heel 2.

In the variant shown in Figure 24, the lower portion 16 of the main structure 3 is formed in one piece (i.e. is monolithic) with the reinforcement pin 14; in other words, the lower portion 16 of the main structure 3 constitutes an extension of the lower portion 22 of the reinforcement pin 14. From another, and perfectly equivalent, point of view, the lower portion 16 of the main structure 3 is integrated in the lower portion 22 of the reinforcement pin 14. This variant allows to reduce the assembly costs, because it is no longer necessary to couple the lower portion 16 of the main structure 3 to the lower portion 22 of the reinforcement pin 14 making, at the same time, the lower portion 16 of the main structure 3 integral to the lower portion 22 of the reinforcement pin 14. Obviously, the reinforcement pin 14 (integrating the lower portion 16 of the main structure 3) is made of high strength structural material (aluminum or steel) , while the remaining part of the main structure 3 is made of non- structural plastic material (typically ABS) . This feature (the reinforcement pin 14 that integrates the lower portion 16 of the main structure 3) shown in Figure 24 can also be used in conjunction with the embodiment shown in Figures 17-19.

The embodiment shown in Figures 25-28 constitutes an evolution of the embodiment shown in Figures 8-9 and 11-13; in this embodiment shown in Figures 25-28, the main structure 3 of the heel 2 presents the slits 8 and 12, while the reinforcement pin 14 is coupled to a series of disk springs 24 fully matching the conformation of the reinforcement pin 14 shown in Figures 20-24. The main structure 3 presents three slits 8 and 12 vertically alternated to one another (in particular two slits 12 and one slit 8 vertically alternated between the two slits 8) ; said slits 8 and 12 have the structural characteristics described above and therefore for their detailed description reference is made to what has already been said above. The reinforcement pin 14 coupled to the series of disk springs 24 is completely analogous to the reinforcement pin 14 shown in Figures 20-24 and previously described and therefore for its detailed description reference is made to what has already been said above.

The heel 2 described above has numerous advantages.

In the first place, the heel 2 described above has an optimal vertical elasticity that allows to reduce the negative stresses on the foot and on the leg of the user of the shoe 1 without penalizing, at the same time, walking which remains "natural" (i.e. the user's walking is not disturbed or otherwise adversely affected by the elasticity conferred by the vertical slits 8 and 12) . This result is obtained thanks to the presence of slits 8 and 12 of different type and alternated to one another that allow to offer adequate resistance also to transverse loads.

In addition, the heel 2 described above is applicable to any type of shoe 1 without significant constructive complications; for example, in Figure 29 a heel for a- women's shoe with a high heel is shown which is provided with a heel 2 of the type described above and is completely different with respect to the shoe 1 shown in Figure 1.

Finally, the manufacturing process to obtain the heel 2 described above is particularly simple and quick and thus economical. In particular, in the heel 2 described above is the main structure 3 to adapt to the external conditions thanks to its intrinsic morphological constitutive characteristics and without the addition of additional components. The possible use of the reinforcement pin 14 does not particularly complicate the manufacturing process since the reinforcement pins are already normally present in many heels for women shoes with high heels.

The advantages of the present invention are particularly evident in a high heel, i.e. when the heel 2 has a height greater than 5 cm. Thus, the present invention is advantageously applied to a heel 2 for a women' s shoe 1 with a high heel, which heel 2 has a height greater than 5 cm.