WO2015097015A1

WO2015097015A1 - Sole, particularly for sports shoes

Info

Publication number: WO2015097015A1
Application number: PCT/EP2014/077789
Authority: WO
Inventors: Angelo Mason; Enrico POLEGATO MORETTI
Original assignee: Diadora Sport S.R.L.
Priority date: 2013-12-23
Filing date: 2014-12-15
Publication date: 2015-07-02
Also published as: ITPD20130358A1; CN105828652A; EP3086677A1; US20170000213A1

Abstract

A sole (10, 110), particularly for sports shoes, which comprises in succession from the bottom: - a tread sole (11, 111), - a hollow mid-sole (12, 112) made of elastic material, with a bottom (14, 114) that has through openings (15, 115) that face opposite faces (16a, 16b) thereof, and at least one upper border (17, 117), which delimits a respective opening that is directed toward the bottom (14, 114) and is raised from it by means of supporting elements (18, 118) at least at the heel (19, 119), which define a succession of lateral passages (22, 122) of the mid-sole (12, 112) that connect its internal cavity to the outside, - a laminar support layer (13, 113) for the foot, which is associated perimetrically with the upper border (17, 1 17) so as to cover the opening, the laminar support layer (13, 113) having extensibility characteristics and the mid-sole (12, 1 12) having flexibility characteristics such that in combination the system returns a thrust in response to the pressure of the foot on the laminar support layer (13, 113) during sports activity.

Description

SOLE, PARTICULARLY FOR SPORTS SHOES

The present invention relates to a sole, particularly for sports shoes.

Currently, in the sports shoe field the need is felt to propose shoes capable of controlling movement and of cushioning the impacts of the foot with the ground.

In this regard, the tread of a sports shoe has the function of ensuring traction on slippery ground, such as wet tarmac, and must withstand wear. In fact, since it is subjected to various stresses, it is composed typically of a rubber mix, for qualities of high resistance and durability, with various sculpting in order to adapt to the walking surface and ensure the best possible grip with it.

Very often, the tread has, in the forefoot region, some flexing grooves that allow, in the last phase of rolling, a better mobility thereof, while in the central part of the waist the tread can be absent, leaving space to the mid- sole in order to reduce the weight of the shoe.

As regards the level of shock absorption, it has to be such as to reduce adequately the excessive load in the region of impact of the foot with the ground and return elastically part of the received energy in order to facilitate especially the thrust phase during rolling, trying to reduce muscular stress and the loads affecting the muscular- skeletal system.

Up to now, in order to meet these needs, mid-soles are known which comprise a thickness of elastically flexible and shock-absorbing material, adapted to conform itself anatomically according to the configurations that the foot of the user assumes during the practice of sports. Currently, mid- soles are made of polymeric material, particularly PU and EVA, acronyms of polyurethane and ethyl vinyl acetate, with reinforcements, known as shanks, in the region of the waist made of TPU or PEBAX, acronyms of thermoplastic polyurethane and of Polyether Block Amides.

The shank arranged in the median region of the central section of the sole ensures better torsional stability both during heel impact and during thrust and especially during lateral movements.

The use of ethyl vinyl acetate, hereinafter abbreviated with its acronym EVA, is widespread because, being an expanded material, it is lightweight and capable of absorbing impacts.

However, one of the problems of EVA is that, due to repeated compressions during use, it loses over time the shock-absorbing characteristics and the elastic return of the thrust phase.

Polyurethane foam would solve this problem, but it is heavier than EVA and subject to hydrolysis over a short time.

Sports shoe manufacturers have proposed some solutions to these problems that consist in embedding, at the heel region, shock-absorbing devices that consist of pads containing air or gel or the like, adapted to be deformed and absorb partly elastically and partly plastically the energy of the impact with the ground.

However, over time, the pads deflate and break easily if subjected to repeated compressions during sports activity.

Another proposed solution is the provision of the mid-sole with a honeycomb structure, which however is still too heavy.

The aim of the present invention is to provide a sole for sports shoes that is light and flexible in order to conform easily to the movements of the foot of the user and at the same time is capable of damping effectively impacts with the ground during sports activities.

Within this aim, an object of the invention is to provide a sole capable of maintaining over time the sought characteristics of shock absorption and thrust.

Another object of the invention is to propose a sole that is simple and can be manufactured at low costs.

This aim and these and other objects that will become better apparent hereinafter are achieved by a sole, particularly for sports shoes, characterized in that it comprises in succession from the bottom: - a tread sole,

- a hollow mid-sole made of elastic material, with a bottom that has through openings that face opposite faces thereof, and at least one upper border, which delimits a respective opening that is directed toward said bottom and is raised from it by means of supporting elements at least at the heel, which define a succession of lateral passages of said mid-sole that connect its internal cavity to the outside,

- a laminar support layer for the foot, which is associated perimetrically with said upper border so as to cover said opening,

said laminar support layer having extensibility characteristics and said mid- sole having flexibility characteristics such that in combination the system returns a thrust in response to the pressure of the foot on said laminar support layer during sports activity.

Further characteristics and advantages of the invention will become better apparent from the description of two preferred but not exclusive embodiments of the sole according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a side view of the sole according to the invention in its first embodiment;

Figure 2 is a bottom plan view of the sole according to the invention, again in the first embodiment;

Figure 3 is a sectional view of Figure 2, taken along the line III-III; Figure 4 is a sectional view of Figure 2, taken along the line IV-IV; Figure 5 is a top plan view of the sole according to the invention, again in the first embodiment;

Figure 6 is a side view of the sole according to the invention in its second embodiment;

Figure 7 is a bottom plan view of the sole according to the invention, again in the second embodiment;

Figure 8 is a sectional view of Figure 7, taken along the line VIII- VIII;

Figure 9 is a sectional view of Figure 7, taken along the line IX-IX; Figure 10 is a top plan view of the sole according to the invention, again in the second embodiment.

With reference to the figures, the sole according to the invention, in its first embodiment, is designated generally by the reference numeral 10.

As clearly visible in the sectional views of Figures 2 and 3, the sole comprises in succession from the bottom a tread sole 11 made of rubber, a hollow mid-sole 12 made of elastic material, and a laminar support layer 13 for the foot.

In particular, the mid-sole 12 is provided in a single piece and made of thermoplastic elastomeric material, preferably PEBAX.

The hollow of the mid-sole 12 is clearly visible in Figures 3 to 5, which show clearly a bottom 14 that has through openings 15 facing opposite faces 16a, 16b thereof, and an upper border 17, which delimits an opening that is directed toward the bottom 14 and is extended along all of the perimeter of the mid-sole 12. The laminar support layer 13 is associated perimetrically with the upper border 17 so as to cover the opening that it delimits.

The upper border 17 is raised from the bottom 14 by means of supporting elements 18 that extend along the perimeter of the sole 10, being raised further by elements that are higher at the heel 19 than the forefoot 20 and the waist 21.

The same support elements 18, as shown in Figure 1 , define a succession of lateral passages 22 of the mid-sole 12 that connect its internal cavity to the outside.

Said passages extend from the border downwardly and are inclined toward the heel 19 or toward the forefoot 20 until they connect to the bottom 14.

In general, the laminar support layer 13 has extensibility characteristics and the mid-sole 12 has flexibility characteristics such that in combination the system returns a thrust in response to the pressure of the foot on the laminar support layer 13 during sports activity.

In particular, it can have lower elasticity characteristics than the mid- sole 12.

More in particular, in this case the laminar support layer 13 has a non- extensible net-like structure preferably made of plastic material, of the type of thermoplastic polyurethane, in short TPU.

In figure 5 it is shown only partially in the region of the heel 19 in order to allow the mid-sole 12 to be visible.

In the case shown, the laminar support layer 13 has limited extensibility characteristics, so as to flex toward each other transversely opposite side walls 23 of the mid-sole 12 when it is subjected to the pressure of the foot. Conveniently, in this case the mid-sole is made of elastically flexible material. Figure 4 is a transverse sectional view, taken at the region of the heel 19, in which A designates the direction of movement of the laminar support layer 13 following the pressure applied thereon by the foot and B designates the directions toward which the substantially non- extensible laminar support layer 13, by curving downwardly, flexes the side walls 23 of the mid-sole 12.

As an alternative, the laminar support layer 13 may comprise a non- extensible net coupled to a film made of plastic material for reinforcement, in order to ensure light weight and flexibility. The plastic material of the film also is constituted preferably by TPU.

In order to ensure the thrust for response to the pressure of the foot on the laminar support layer 13, such layer can have, in another version, greater elasticity characteristics than those of the mid-sole 12 and can consist for example of an elastically flexible net made of plastic material, again made of TPU. In this case the deformation thereof does not flex the side walls 23 of the mid-sole 12, the material of which is less elastic, but the material itself deforms downwardly in an elastic manner.

The laminar support layer 13 can be glued to the upper border 17, or preferably, as in the case described, is associated perimetrically with the upper border 17 by heat-sealing two films 24 made of plastic material, between which it is interposed at its peripheral region, with the upper border 17.

The laminar support layer 13 can be likewise associated with the upper border 17 of the mid- sole 12 by gluing.

As clearly visible in the figures in top plan and bottom plan view, the through openings 15 are defined by the crossing of a succession of transverse elements 25 with a longitudinal pin 26.

The transverse elements 25 are shaped, substantially parallel to each other and extending from the lower end of the supporting elements 18 between the two opposite side walls 23 of the mid-sole 12, connecting them.

The tread sole 1 1 substantially covers the transverse elements 25 on the side for contact with the ground at the heel 19 and at the forefoot 20.

The transverse elements 25„ at the waist 21 are conveniently thinner than those of the regions of the heel 19 and of the forefoot 20, constituting substantially an extension of the support elements 18 under the sole of the foot.

In the second embodiment, the sole is designated generally by the reference numeral 110 and is shown in Figures 6 to 10.

In particular, in the sectional view of Figure 8, it can be seen that it comprises, as in the previous embodiment, in succession from the bottom a tread sole 111 made of rubber, a hollow mid-sole 1 12 made of elastic material and a laminar support layer 1 13 for the foot.

The cavity of the mid-sole 112 is clearly visible in Figures 8 to 10, in which a bottom 114 is recognizable which has through openings 115 that face opposite faces 1 16a, 1 16b thereof, and an upper border 117, which delimits an opening that is directed toward the bottom 114 and is extended along the entire perimeter of the mid-sole 112. The laminar support layer 113 is associated perimetrically with the upper border 117 so as to cover the opening that delimits it. In Figure 10 the laminar support layer 113 is shown only partially, as in the previous embodiment, in order to leave the rest of the mid-sole 1 12 in view.

Unlike the previous embodiment, the mid-sole 112 is provided in two parts, with an upper border 117 provided separately from the hollow portion 127 of the mid-sole 112.

In this embodiment also, the upper border 117 is raised from the bottom 114 by means of supporting elements 118 that extend along the perimeter of the sole 1 10, raised more by higher elements at the heel 119 than at the forefoot 120 and at the waist 121.

In particular, the supporting elements 118 appear from the outside as substantially tubular elements, with quadrilateral cross-section in the example and with rounded corners, provided in a single piece with the bottom 114 of the mid-sole 112. The series of these elements, arranged laterally adjacent along the perimeter of the mid-sole 112 as indicated in Figure 6, defines a succession of lateral passages 122 that connect the internal cavity of the mid-sole 112 to the outside.

Actually, the supporting elements 118 are provided in a single piece not only with the bottom 114 but also with each other and the same figure allows to notice that they are alternated on the outside by separators 128 in the described embodiment.

Moreover, the supporting elements 118 arranged side by side along the perimeter constitute substantially the wall of the hollow portion 127.

The tread sole 11 1 is made of rubber and covers, at least partially, the bottom 114 on the side for contact with the ground.

The upper border 117 and the separators 128 are made of thermoplastic elastomeric material, preferably two types of PEBAX, and the hollow portion 127 is made of polymeric material, preferably EVA. In this embodiment also, a peculiarity of the sole 110 resides in that the laminar support layer 1 13 has extensibility characteristics and the mid- sole 112 has flexibility characteristics such that in combination the system returns a thrust in response to the pressure of the foot on the laminar support layer 113 during sports activity. The materials of the support layer 113 and of the mid-sole 112 can be the same described in the previous embodiment, and so can their respective characteristics, one relative to the others, can be of the same type already described.

It can be noted from figure 10 that the laminar support layer 1 13 consists of a net.

It can have limited extensibility characteristics, so as to flex toward each other transversely opposite side walls 129 of the mid-sole 112 when it is subjected to the pressure of the foot, as described previously and shown in Figure 4 for the first embodiment.

Again, in this case the laminar support layer 113 is associated perimetrically with the upper border 117 by heat- sealing two films 124 made of plastic material, between which it is interposed at its perimetric region, with the upper border 117.

However, the laminar support layer 113 can be equally associated with the upper border 117 of the mid-sole 112 by gluing.

In other constructive variations, the mid-sole 12 or 112 can have multiple upper borders 17, for example, one in the heel region and one in the forefoot region, the openings of which are covered by respective laminar support layers 13 or 113.

Advantageously, in the provision of a shoe, the use of a sole 10 or

110 according to the invention, particularly with a net-like laminar support layer 13 or 1 13 to be coupled to other vapor-permeable elements of the insole, allows to obtain a shoe with vapor-permeability characteristics, creating a ventilation buffer volume in the cavity of the mid-sole 12 or 112.

It should be noted that during the use of a shoe that comprises a sole 10 according to the invention, with a laminar support layer 13 having lower elastic characteristics than the mid-sole 12, the pressure of the foot of the user causes a lowering of the laminar support layer 13 that causes the elastic deformation of the opposite side walls 23 that flex substantially in direction B, moving closer in the manner already described and shown in Figure 4.

During rolling, the compression to which the portion of sole has just been subjected occurs and the laminar support layer 13, by cooperating with the mid-sole 12, resumes its initial position, releasing the accumulated energy with a "springboard" thrust effect against the foot.

The laminar support layer 13 facilitates significantly the thrust phase during sports activity.

The same remarks can be repeated for the second embodiment of the sole 110.

For both embodiments, the "springboard" thrust effect is obtained also if the laminar support layer has greater elasticity characteristics than the mid-sole, and is due in this case to the elastic return of such laminar support layer.

It should be noted that the cavity of the mid-sole allows to provide a structure that is flexible, in order to conform anatomically to the configurations of the foot, and lightweight thanks to the reduced quantity of material used.

Moreover, the use of a laminar support layer, of the type described, allows to keep unchanged over time the characteristics of elastic performance and thrust, and likewise the cavity inside the mid-sole allows, by limiting at the same time the weight of the structure, to cushion the impact with the ground, reducing the dependence of this characteristic on the material used.

It should be noted also that in both embodiments the supporting elements 18 and 1 18 not only space the upper border 17 or 117 from the bottom 14 or 114 of the mid-sole 12 or 112 but are also designed to cushion impacts with the ground and to return at least partially the energy in the thrust phase.

In practice it has been found that the invention achieves the intended aim and objects, by providing a sole capable of conforming easily to the foot during use of the shoe and to cushion effectively impacts with the ground while ensuring the necessary elastic return in the thrust phase.

Moreover, the sole maintains the initial cushioning and thrust characteristics longer over time.

Another advantage of the sole according to the invention resides in the particular aesthetic effect due to the fact that the through openings in the bottom of the mid-sole and the lateral passages make the inside of the cavity and the laminar support layer visible from the bottom.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; all the details may further be replaced with other technically equivalent elements.

In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to requirements and to the state of the art.

The disclosures in Italian Patent Application No. PD2013A000358 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A sole (10, 110), particularly for sports shoes, characterized in that it comprises in succession from the bottom:

- a tread sole (11, 111),

- a hollow mid-sole (12, 112) made of elastic material, with a bottom (14, 114) that has through openings (15, 115) that face opposite faces (16a, 16b) thereof, and at least one upper border (17, 117), which delimits a respective opening that is directed toward said bottom (14, 1 14) and is raised from it by means of supporting elements (18, 118) at least at the heel (19, 119), which define a succession of lateral passages (22, 122) of said mid-sole (12, 112) that connect its internal cavity to the outside,

- a laminar support layer (13, 113) for the foot, which is associated perimetrically with said upper border (17, 117) so as to cover said opening, said laminar support layer (13, 113) having extensibility characteristics and said mid-sole (12, 112) having flexibility characteristics such that in combination the system returns a thrust in response to the pressure of the foot on said laminar support layer (13, 113) during sports activity.

2. The sole according to claim 1, characterized in that said laminar support layer (13, 113) has limited extensibility characteristics, so as to flex toward each other transversely opposite side walls (23, 123) of said mid-sole (12, 112) when it is subjected to the pressure of the foot, said mid-sole (12, 112) being made of elastically flexible material.

3. The sole according to claim 2, characterized in that said laminar support layer (13, 113) has lower elasticity characteristics than said mid-sole (12, 112).

4. The sole according to claim 3, characterized in that said laminar support layer (13, 113) comprises at least one non-extensible net.

5. The sole according to claim 3, characterized in that said laminar support layer (13, 113) comprises at least one substantially non- extensible net coupled to at least one film made of plastic material.

6. The sole according to claim 5, characterized in that said substantially non-extensible net is made of plastic material.

7. The sole according to claim 1, characterized in that said laminar support layer (13, 113) had greater elasticity characteristics than said mid- sole (12, 112).

8. The sole according to claim 7, characterized in that said laminar support layer (13, 113) comprises an elastically flexible net.

9. The sole according to claim 8, characterized in that said elastically flexible net is made of plastic material.

10. The sole according to claim 1, characterized in that said upper border (17, 1 17) is extended along the entire perimeter of said mid-sole (12, 112).

11. The sole according to claim 1, characterized in that said laminar support layer (13, 113) is associated perimetrically with said upper border (17, 117) by heat-sealing two films (24, 124) made of plastic material, between which it is interposed at its perimetric region, with said upper border (17, 117).

12. The sole according to one or more of the preceding claims, characterized in that said mid-sole (12) is made in a single piece of thermoplastic elastomeric material.

13. The sole according to claim 1, characterized in that said supporting elements (18) protrude downwardly from the upper border (17) and are inclined toward said heel (19) or toward said forefoot (20) so as to connect to said bottom (14).

14. The sole according to claim 1, characterized in that said through openings (15) of said bottom (14) are defined by the crossing of a succession of transverse elements (25) with a longitudinal pin (26), said transverse elements (25) being substantially parallel to each other and extending from the lower end of said supporting elements (18) between said two side walls (23) of said mid-sole (12).

15. The sole according to claim 14, characterized in that said tread sole (11) covers said transverse elements (25) on the side for contact with the ground, adapting to their contour, at said heel (19) and at said forefoot (20).

16. The sole according to claim 1, characterized in that said supporting elements (118) are externally substantially tubular and with rounded edges and are provided in a single piece with said bottom (114) of said mid-sole (112).

17. The sole according to claim 16, characterized in that a succession of said supporting elements (118), which are arranged side by side along the perimeter of said mid-sole (112), defines a succession of said lateral passages (122) that connect the internal cavity of said mid-sole (112) to the outside.

18. The sole according to claim 17, characterized in that said supporting elements (118) are alternated in their succession, on the outer side, by separators (128).

19. The sole according to claim 1, characterized in that said mid-sole (112) is provided in two parts, with an upper border (117) that is provided separately from the hollow portion (127) of said mid-sole (112).

20. The sole according to claims 18 and 19, characterized in that said upper border (117) and said separators (128) are made of thermoplastic elastomeric material and said hollow portion (127) is made of polymeric material.