Footwear with an adjustable stabilizing system, in particular for pronation and/or supination control

Abstract

A footwear has a sole that comprises an adjustable stabilising system, in particular to control phenomena of pronation and/or supination. The stabilisation system comprises at least one adjustment member capable of selectively taking at least two alternative positions within a respective seat present in a component of the sole, the adjustment member having a body with at least two portions or sectors that present different degrees of compressibility.

Description

BACKGROUND OF THE INVENTION

The present invention relates to footwear, particularly sports footwear, having a sole fitted with an adjustable stabilising system.

It is known that the gait, that is the placing of the foot on the ground during walking or running, varies from person to person depending on the morphological and/or biomechanical characteristics of the subject. Some people rest their foot on the ground in a “neutral” manner, that is substantially correctly from the biomechanical standpoint; on the contrary in others some defect occurs in resting the foot on the ground, in particular due to excessive pronation (or inverted foot rest) or excessive supination (or everted foot rest). Very briefly, in pronation the foot takes on a position in which most of the body weight is loaded onto the inner (in technical jargon the medial) edge of the foot. On the contrary, in supination the foot takes on a position in which the body weight is loaded onto the outer (in technical jargon the lateral) edge of the foot. Even some people who are immune to gait defects when walking normally may suffer from excessive pronation or supination during running or sports activities in general.

For the above reasons, “neutral” footwear and “stable” footwear are currently available on the market, in particular for practising running.

The “neutral” footwear is provided with a midsole of uniform hardness or rigidity and is thus indicated for persons who do not suffer from any defect in resting the foot. The “stable” footwear is, on the contrary, provided with a midsole of locally differentiated hardness or rigidity and is therefore indicated for persons who have problems of excessive pronation or supination, particularly noticeable during prolonged running.

Usually the midsoles of “stable” footwear have, in the medial zone of the heel, one or more insertions of greater hardness than the rest of the midsole and/or conformed so as to increase the resistance to compression of the midsole in that area; in this manner greater support may be provided to the foot, controlling and/or supporting pronation when resting the foot on the ground. An example of this type of solution is described in EP-A-0 315 340, and reference may also be made to the introduction of this prior document for a detailed examination of the problem mentioned above.

Manufacturers of footwear must therefore produce both “neutral” footwear and “stable” footwear and, in the case of “stable” footwear fitted with inserts, it is also necessary that manufacturers produce numerous versions of a single model of footwear, differentiated one from another in terms of the hardness or compressibility of the relative midsole (as has been seen, the load when resting the foot on the ground varies depending on biomechanics and the person's weight).

This diversification of production involves problems both for the footwear manufacturer, who must set up diversified plant, and for the retailer, who must acquire a larger number of versions of a single model of footwear in the attempt to meet consumers' differing demands.

In view of resolving these drawbacks, footwear has been proposed in which the midsole is fitted with inserts defining at least one air chamber, fitted with valve-operated means of control and capable of being inflated to different pressures; in solutions of this type the operative configuration of the midsole may therefore be modified depending on the extent of pronation that must be corrected. An example of this technique is described in WO 98/56272. Solutions of the type indicated are complicated and expensive, as well as difficult to use for the purpose of adjusting the degree of compressibility of the midsole; apart from this, should said valve break the adjustment system would become unusable.

From the document EP-A-0 258 718 footwear for practising running is also known in which the means that oppose excessive pronation comprises a cushioning strip, which embraces the midsole externally at the heel zone; the strip is fixed in a removable manner to the midsole, so as to enable it to be replaced if necessary. This solution has been found to be unreliable over time, chiefly because use of the footwear involves a risk of damaging the cushioning strip and the means that enable it to be fixed in a removable fashion to the midsole.

SUMMARY OF THE INVENTION

In the light of the above, the present invention aims to produce footwear provided with a new system of adjustable stabilisation, particularly to control pronation and/or supination, of simple and economic construction, as well as being versatile and reliable in use. In this general sphere, a particular purpose of the invention is to produce footwear having a stabilising system conceived to facilitate and simplify the phase of adjusting the degree of compressibility of the respective sole, be this carried out by the producer, the retailer or the consumer.

This and further purposes, which will become clearer below, are achieved according to the present invention by footwear having the characteristics indicated in the attached claims, which constitute an integral part of the descriptive content of this patent application.

BRIEF DESCRIPTION OF THE DRAWINGS

Further purposes, as well as the characteristics and advantages of the present invention, will be clear in the description that follows and in the attached drawings, provided as a simple example for explanatory purposes with no limiting intent, in which:

FIG. 1 is a view in elevation and partial section in diagram form of sports footwear according to the invention;

FIGS. 2 and 3 are views in lateral elevation in diagram form of the side defined as “lateral” and of the side defined as “medial” of a midsole of the footwear in FIG. 1;

FIGS. 4 and 5 are views in diagram form, respectively in plan and in lateral elevation, of a main body of the midsole in FIGS. 2 and 3;

FIGS. 6 is a diagrammatic section along the line VI-VI of FIG. 4;

FIG. 7 is a front elevation in diagram form of an adjustment member being part of a stabilising system of the footwear according to the invention;

FIG. 8 is a diagrammatic section along the line VIII-VIII of FIG. 7;

FIGS. 9 and 10 show, in diagram form, respectively in front and lateral elevation, an insert of the member in FIGS. 7 and 8;

FIG. 11 is a section in diagram form along the line XI-XI of FIG. 10;

FIG. 12 is a diagrammatic plan of the midsole in FIGS. 2 and 3, including the body in FIGS. 4-6, the member in FIGS. 7-8 and the insert in FIGS. 9-11;

FIG. 13 is a diagrammatic section along the line XIII-XIII of FIG. 12;

FIG. 14 is a front elevation in diagram form of an adjustment member being part of a stabilising system according to a possible variant of the invention;

FIG. 15 is a section in diagram form along the line XV-XV in FIG. 14.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1, footwear for athletics or for practising running, fabricated according to the invention, is indicated overall as 1; the footwear 1 has an upper part or upper 2 and a lower part or sole that, in the case given as an example, comprises an outsole 3 and a midsole 4.

The specifics of the upper 2 and of the outsole 3 lie outside the scope of the present invention and will therefore not be illustrated or described in detail; it suffices here to mention that the outsole 3 may be made of synthetic material, for example rubber of differentiated hardness, formed in a single piece or in a number of separate pieces.

The midsole 4 has a body 4a that presents an upper face, a lower face and a peripheral profile or edge; this peripheral profile has a lateral segment, shown in FIG. 2, and a medial segment, shown in FIG. 3; the medial segment is substantially the part of the peripheral profile of the midsole 4 that faces towards the other foot of the user when the footwear 1 is being worn, whereas the lateral segment is substantially the part of the peripheral profile opposed to the medial segment.

The midsole 4 is positioned between the upper 2 and the outsole 3 and on it, inside the footwear 1, rests an arch-support insole, not shown; for this purpose a hollow 4b is defined in the upper zone of the midsole 4, within which said insole is at least partially housed.

The body 4a of the midsole 4 may be obtained by moulding a compressible material that is elastic and light, such as for example EVA, and then joined to the upper 2, for example by gluing it around the peripheral zone of its upper face; the outsole 3 may be associated to the lower face of the body 4a by gluing.

According to the main aspect of the invention, the midsole 4 is fitted with an adjustable stabilising system, to control pronation and/or supination, indicated (as a whole) with D in FIG. 1.

FIGS. 4-6 show the body 4a of the midsole 4; in these figures only the lateral segment of the body 4a is illustrated (FIG. 5), but it should be considered that fabrication is similar for the medial segment (see for example FIG. 3).

As may be seen in FIG. 4, a cavity or seat 10 is present in the posterior part of the body 4a, and in particular in the heel zone, having a prevalently circular lobed section; in the case shown as an example, the peripheral wall of the seat 10 is shaped to define four lobes 10a, 10b, 10c, 10d; the lobes 10a, 10b face respectively towards the anterior end and towards the posterior end of the body 4a, whereas the lobes 10c, 10d face respectively towards the said medial segment and the said lateral segment, and communicate through open passages with the outside of the body 4a. In correspondence with these open passages, covering elements 11 are mounted, shown in particular in FIGS. 5 and 6; in the example the elements 11 are formed at least in part of transparent synthetic material, so as to form windows 11a that face onto the inside of the seat 10, as is visible for example in FIG. 5. As will be clear below, the windows 11 embody means of inspection, for the purpose of allowing the type of adjustment set on the stabilising system, that is the specific object of the invention, to be checked visually.

The seat 10 is destined to receive an adjustment member, indicated with 12 as a whole in FIGS. 7 and 8, whose shape is substantially complementary to that of the seat 10, but of slightly smaller size. The member 12 thus substantially has the shape of a disk defining, along its peripheral wall, four lobes 12a, 12b, 12c, 12d, at approximately 90° one from another.

The member 12 is formed such as to present adjacent sectors or portions of differing hardness, that is having different degrees of compressibility. In the case given as an example, and as is shown in FIG. 7, the member 12 comprises three sectors, indicated with S1, S2 and S3, where the sector S1 includes the lobes 12a and 12d, the sector S2 includes the lobe 12b and the sector S3 includes the lobe 12c; as a simple example, the sector S1 may have a hardness of 55 Shore C, the sector S2 a hardness of 65 Shore C and the sector S3 a hardness of 75 Shore C.

The member 12 may be formed of a single material, but with the various sectors of differentiated hardness or density, or may be made of different materials of different hardnesses that form the respective sectors. The material or materials constituting the member 12 might be polymers, such as thermoplastic polyurethane (TPU), expanded two-component polyurethane (hexocyanate polyol) or Pebax™ (polyammide and TPU), or expanded cross-linking materials such as EVA, that can be injected or heat formed. The synthetic body of the member 12 might also be configured so as to present a cavity of a substantially toroidal shape, subdivided into sub-chambers containing a fluid (such as air) at different pressures, so as to define a corresponding number of sectors having different degrees of compressibility.

As FIG. 8 shows, a circular housing 12e is formed in the lower face of the member 12, with at its centre a hexagonal seat 12f; the member 12 also presents a central axial hole 12g, having an end that opens in correspondence with the seat 12f.

The housing 12e is destined to receive an insert, here comprising a plate 13 shown in FIGS. 9-11, formed as a single piece of rigid material, for example a thermoplastic material. The plate 13 presents a circular base wall 13a, from the centre of which a tubular part of limited height 13b rises, which in the case given as an example has a hexagonal inner and outer section.

FIGS. 12 and 13 show the midsole 4 fitted with the adjustable stabilising system, respectively in plan and in section.

As may be seen, the member 12 is inserted within the seat 10, with the lobes 12a-12d of the member occupying the lobes 10a-10d of the seat. The lower face of the member 12, fitted with the plate 13, rests on the bottom of the seat 10. In the assembled condition, two opposing lobes of the member 12—in the example lobes 12c and 12d—are partially visible through the windows 11a of the covering elements 11.

Production of the midsole 4 is very simple.

The body 4a of the midsole 4 may be moulded, for example in EVA, in ways and employing means that are known, such as to present the seat 10 with the relative passages for the elements 11; these elements 11, of transparent material, may be over-moulded or co-moulded with the body 4, or applied subsequent to the formation of the body 4a and glued to it.

The member 12, fitted with the plate 13, is then inserted into the seat 10, with the tubular part 13b of the plate 13 inserted into the seat 12f. The plate 13 is for preference glued inside the respective seat 12e of the member 12, exploiting the wide flat surface of the base wall 13a.

After assembling the upper 2 onto the sole, an insole of the arch support type may be assembled inside the footwear 1, in the hollow 4b, thus covering the upper side of the adjustable stabilising system. In the condition shown, in correspondence with the windows 11a of the elements 11 present on the medial and lateral segments of the peripheral profile of the midsole 4, the lobes 12c and 12d of the member 12 are partially visible. In the preferred embodiment of the invention, the various sectors S1, S2 and S3 have visibly differentiated colours or appearances, or bear different indications in the part visible through the windows 11a.

The adjustable system of the footwear is very simple to operate.

The member 12, not being fixed in the seat 10 of the body 4a, may be rotated through 360° around an axis indicated as X in the figures, so that selectively it may take up a plurality of possible positions within the seat 10. In the case shown as an example, four alternative angular positions are provided for, defined by the number of lobes of the seat 10 and of the member 12.

To produce rotation of the member 12 it is sufficient to insert the tip of an appropriate tool into the hole 12g of the member 12; in the case given as an example this tool comprises an Allen key of suitable size to engage in the hexagonal section of the tubular portion 13b of the plate 13 (it is clear that the portion 13b might be shaped so as to co-operate with the tip of a tool of a different type, such as a screwdriver or a spanner with square section). Access to the hole 12g may be obtained by removing the arch-support insole from the footwear 1 or, alternatively, a passage substantially coaxial with the hole 12g may be provided in the arch support insole.

Using the tool the member 12 may be made to rotate clockwise or anticlockwise in the seat 10, so as to position the sector S1-S3 of interest in the desired position of the medial or lateral part of the heel; as has been said, the member 12 is here predisposed to be rotated by 90° to change position; in consequence there are four possible different combinations of positions of the sectors is S1-S3 in the medial zone or lateral zone of the heel, and that is:

1) medial S3, lateral S1;

2) medial S2, lateral S1;

3) medial S1, lateral S3;

4) medial S1, lateral S2.

The stabilisation system described, with two or more differentiated degrees of hardness, thus enables the degree of resistance to compression of the midsole 4 to be varied for the purposes of controlling pronation and/or supination of the foot.

In the adjustment phase, even when this is performed with the arch-support insole removed, the member 12 is for preference maintained within the seat 10 by means of the extreme portions of its two opposed lobes inserted in the elements 11; as may be realised, rotation substantially comes about “stepwise” and is enabled thanks to the deformability of the materials comprising the body 4a and the member 12; engagement between the lobes of the member 12 and those of the seat 10 ensures that the adjusted position that is set will be maintained.

Thanks to the different colours or indications of the sectors S1, S2, S3, the adjustment that has been performed may be perceived directly from outside the footwear 1 for the medial and lateral segments, through the windows 11a of the elements 11.

From what is described above it is clear that the degree of compressibility of the midsole 4 may be modified in an extremely simple fashion, depending on the morphological and biomechanical characteristics of the consumer. This is particularly advantageous, not only for the manufacturers and retailers of the footwear, but also for the consumer who may, at need, modify the adjustment in view of different occasions of use of the same footwear. The adjustable stabilisation system described may be inserted in any type of midsole of footwear for athletics or sports in general, for example for practising running or tennis; the invention is capable of being used with any type of footwear.

Naturally, the construction details and embodiments may be varied with regard to what is described and illustrated here, without thereby departing from the scope of the present invention as defined by the attached claims.

In the example described above, without limiting intent, the system according to the invention is operative in the heel zone of the footwear 1, but it is clear that it could also be provided in the zone of the forefoot; one and the same footwear could if desired to be provided with more than one adjustment systems D, for example one in the heel zone and the other in the forefoot zone.

The number of positions of the member 12 that can be selected may naturally be more or fewer than four, and may vary depending on the type of footwear. The profile of the seat 10 and of the member 12 might also be different from that given as an example, the possibility remaining that a plurality of selectable positions may be determined. Also the dimensions of the member 12 might be different depending on the type of footwear (in that light, for example, it is known that the midsoles of training footwear are in general wider and thicker than those of competition footwear).

In a possible variant, for example for footwear to be used in the gymnasium, the system might be conceived so as to enable direct adjustment from outside the footwear. In that variant, the elements 11 are open, that is configured such as to comprise openings through which respective portions of the peripheral edge of the member 12 project directly outside the midsole 4; in this fashion, the member 12 embodies a sort of wheel, which may be made to rotate manually without the need for tools, acting on said peripheral edge.

In another possible variant, the elements 11 and the relative passages may be omitted, and adjustment may be made by extracting and subsequently re-inserting the member 12 into the seat 10, in a different angular position than previously; in this case, the footwear 1 is provided with a removable arch-support insole.

A possible variant of the invention is represented in FIGS. 14 and 15, which use the same reference numbers as the previous figures to indicate the elements technically equivalent to those already described. In this variant the body of the member 12 is formed from a single material, for example EVA, so as to define a plurality of chambers or containers of air or other fluid, indicated with S1a, S2a and S3a, at different pressures; each chamber extends in a respective sector S1, S2, S3 of the member 12, in such a fashion that these sectors have differentiated degrees of compressibility.

Claims

1. Footwear having a sole that comprises an adjustable stabilising system, in particular to control phenomena of pronation and/or supination, wherein the adjustment system comprises at least one adjustment member capable of selectively taking at least two alternative positions within a respective seat present in a component of the sole the adjustment member having a body with at least two portions or sectors that present different degrees of compressibility.

2. Footwear according to claim 1, wherein different positions of said member within said seat correspond to different positions of one said sector with respect to a specific zone of the peripheral profile of the sole.

3. Footwear according to claim 2, wherein

said seat extends between a medial zone and a lateral zone of the peripheral profile of the sole, and

in at least one of said positions, a first of said sectors lies at least partially in said medial zone and a second of said sectors (S1) lies at least partially in said lateral zone.

4. Footwear according to claim 1, wherein said member is angularly rotatable or can be moved in, or with respect to, said seat.

5. Footwear according to claim 1, wherein said seat and said member have substantially complementary peripheral profiles.

6. Footwear according to claim 4, wherein said component comprises the body of a midsole of compressible material, said member is approximately disk-shaped and said seat has an approximately circular section.

7. Footwear according to claim 4, wherein said seat and said member have peripheral profiles each defining two or more projections or lobes.

8. Footwear according to claim 1, wherein said seat communicates with at least one passage that opens onto a peripheral edge of said component of the sole, through said passage at least part of one of said sectors being visible and/or accessible from outside the footwear.

9. Footwear according to claim 8, wherein said sectors have, at least in the respective parts visible through said passage, different colours or appearances or indications one from another.

10. Footwear according to claim 8, wherein said passage is covered by an element formed at least in part of transparent material.

11. Footwear according to claim 4, wherein said member is arranged to be displaced angularly between said alternative positions using a tool.

12. Footwear according to claim 1, wherein each of said sectors presents at least one chamber containing a fluid, the chambers of different sectors being at different pressures.

13. Footwear according to claim 1, wherein said seat is formed in a heel part of the sole.