FOOTWEAR WITH IMPROVED UPPER

Abstract

Flexible shoe extending between rear and front ends, between lateral and medial sides, and between the sole assembly and an upper end of an upper. The upper includes an outer shell including an inner and outer layers, the latter having a foot insertion opening with rear and front divisions, the latter extending between lateral and medial edges. A device tightens the upper by bringing the lateral edge toward the medial edger. The inner layer extends opposite the outer layer and in the area of the front division of the foot insertion opening, between the lateral and medial edges. The inner layer is liquid-impermeable and flexible. When the lateral and medial edges of the outer layer are brought toward one another, the distance between the lateral and medial edges is shorter than the portion of the inner layer in the area of the front division or the foot insertion opening.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon French Patent Application No. FR 17/00405, filed Apr. 12, 2017, the disclosure of which is hereby incorporated by reference thereto in its entirely, and the priority of which is claimed under 35 U.S.C. § 119.

BACKGROUND

1. Field of the Invention

The invention relates to a walking or sports article of footwear, such as a shoe, having a liquid-impermeable upper. This shoe can be used in fields such as walking, running on flat or mountainous terrain, skateboarding, ball sports, cross-country or telemark skiing, snowboarding, snowshoeing, or others.

2. Background Information

Depending upon the intended uses, a shoe must have a certain flexibility and a good damping capability. Flexibility must be understood as an ability to follow certain deformations of the foot of a user. This is intended, for example, to enable good foot rolling movement when walking. Damping is intended to reduce or even prevent fatigue or injuries that may result from supports or impacts on the ground, or from various forces.

The shoe must also fulfill other functions such as preserving foot comfort, for example by preventing intrusion of water, that is to say, by ensuring that the foot remains dry or is subject to the lowest possible moisture rate.

To this end, it is known to make a flexible shoe such as shown with reference to FIGS. 1-3, which are part of a set that is described in detail below. According to these drawing figures, a shoe 1 comprises a sole assembly 2 and an upper 3, the upper comprising an outer shell 4, which itself comprises an outer layer 5 and an inner layer 6.

For example, the outer layer 5 has mechanical strength properties, such as resistance to wear and tear or resistance to the tightening forces exerted by a tightening device provided with a lace 7. The outer layer 5 has a root insertion opening 8 divided into a rear division 9, in which a portion of the ankle or of the lower leg of the user is received, and a front division 10 located above the foot, or at the front of the lower leg and above the foot, after putting on the shoe. The front division 10 makes it possible to easily increase or decrease the surface of the opening 8, and therefore to easily put on the shoe, tighten the upper, and take off the shoe.

The inner layer 6 has other properties, such as liquid impermeability, in order to carry out the sealing function. Usually, the inner layer 6 extends opposite the outer layer 5, thereby rendering most of the upper 3 impermeable to liquids. In order for the upper to be impermeable in its entirety, the front division 10 of the foot insertion opening 8 must be liquid-tight. The division 10 is generally hidden by an outer flap 11, an inner flap 12, and an insert 13 positioned between the flaps. The inner flap 12, impermeable to liquid, is connected to the inner layer 6 by means comprising one or more seams 14 and one or more strips 15. These strips are attached by gluing in the area of the seams 14, to prevent water from seeping therethrough.

The above construction renders the upper 3 impermeable to liquid, such as water, and therefore keeps the foot dry. The absence of water in the shoe significantly limits the occurrence of injuries. Consequently, a shoe according to the prior art is generally satisfactory for the user. However, certain disadvantages have nevertheless been observed.

First, a liquid-impermeable shoe according to the prior art sometimes offers insufficient comfort in the area of the front division of the foot insertion opening, particularly when practicing a sporting or intense activity. When the upper is tightened, substantial pressure can be exerted locally on the top of the foot, in correlation with the action of the lace. It is notably in the area of the seams and extra thicknesses created by the strips that excessive pressure can occur, as the upper is more rigid in these areas of extra thickness. As a result, injuries may occur.

Another disadvantage is related to the relative complexity of the structure of a shoe having a liquid-impermeable upper. Because of the number of parts involved, the manufacture of such a shoe is quite lengthy and expensive. For example, as understood with reference to FIG. 3, in a schematic representation, it is quite difficult to affix the constituent elements of the upper 3 to one another. This upper is manufactured with a generally V-shaped preform, the opening angle α of which is between 20 and 40 degrees. In fact, the elements are assembled flat, with the exception of the inner flap 12, which must therefore be deformed to enable its edges to be positioned for assembly. This operation is difficult and time-consuming. In addition, it is necessary to add the strips 15 (see FIG. 2), as mentioned above, which further increases the time required for the manufacture.

SUMMARY

In view of the preceding, the invention provides an improved shoe. In particular, the invention increases comfort in a shoe having a liquid-impermeable upper. The invention also optimizes the manufacture of the shoe, making it faster and more economical, compared to a shoe according to the prior art.

To this end, the invention provides a flexible shoe comprising a sole assembly and an upper, the shoe extending lengthwise from a rear end to a front end, widthwise between a lateral side and a medial side, and heightwise from the sole assembly to an upper end, the upper comprising an outer shell, the outer shell comprising an outer layer and an inner layer, the outer layer having a foot insertion opening, the foot insertion opening having a rear division and a front division, the front division extending in the direction of the shoe width, between a lateral edge and a medial edge, the shoe further comprising a device for tightening the upper by bringing the lateral edge and medial edge closer to one another.

A shoe according to the invention includes the following features:

• • the inner layer extends opposite the outer layer and in the area of the front division of the foot insertion opening, between the lateral edge and the medial edge;
  • the inner layer is impermeable to liquid;
  • the inner layer is flexible; and
  • in the direction of the shoe width, when the lateral edge and medial edge of the outer layer are brought closer to one another, the distance between the lateral edge and the medial edge is shorter than the portion of the inner layer extending in the area of the front division of the foot insertion opening.

The structure of a shoe according to the invention is such that the inner layer of the outer shell extends continuously from the lateral side to the medial side, passing via the front division of the foot insertion opening. As a corollary, the inner layer comes into contact with the foot of the user in a more homogeneous, or uniform, manner. Also, the mechanical properties of the outer shell are more uniform from the lateral side to the medial side, in particular with respect to bending or flexing. This means for example that the hard spots observed in the area of the strips of a shoe according to the prior art are not found on a shoe according to the invention: the outer shell is more homogeneous with respect to its flexibility. As a result, comfort is better distributed; no hard spot is noticeable. It follows that the forces exerted by the upper are more evenly distributed on the foot, especially in the region of the front division of the foot insertion opening. In other words, the distribution of the tightening forces is more homogeneous or uniform on the top of the foot, in the area of the instep, or even simultaneously in the area of the instep and in the area of the flexion fold, that is, the flexion crease. A resulting advantage is greater foot comfort in the shoe.

Another consequence of the structure of a shoe according to the invention is a simpler construction compared to a shoe according to the prior art. The invention allows for a reduction in the number of parts required to make the shoe. As described below, the invention also facilitates the shoe manufacturing process, requiring a reduced number of operations and further simplifying such operations. It follows in particular that the parts forming the structure of the shoe are more easily assembled. The resulting advantages include shorter manufacturing time, reduced manufacturing cost, and greater manufacturing homogeneity, or uniformity. This latter feature means that the differences in fitting volume between two shoes of the same size are reduced, compared to the differences that are observed on shoes according to the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention will be better understood from the description that follows, with reference to the annexed drawing figures illustrating prior art and non-limiting embodiments, in which:

FIG. 1 is a perspective view of a shoe according to the prior art;

FIG. 2 is a transverse cross section of the shoe along the line 11-11 of FIG. 3;

FIG. 3 is a flat partial schematic view of a preform of the outer shell of the shoe of FIG. 1;

FIG. 4 is a cross section of the preform along the line IV-IV of FIG. 3;

FIG. 5 is a perspective view of a shoe according to a first embodiment of the invention;

FIG. 6 is a transverse cross section of the shoe along the line VI-VI of FIG. 5, in a case in which the device for tightening the upper exerts a tightening action;

FIG. 7 is a view similar to that of FIG. 6, in a case in which the device for tightening the upper does not exert a tightening action;

FIG. 8 is a flat partial schematic view of a preform of the inner shell of the shoe of FIG. 5;

FIG. 9 is a view similar to that of FIG. 8, according to a second embodiment of the invention, and

FIG. 10 is a view similar to that of FIG. 8, according to a third embodiment of the invention.

DETAILED DESCRIPTION

The first embodiment described below relates, for example, to a flexible shoe for walking on firm ground or in snow. However, the invention is applicable to other fields, such as those mentioned above.

The first embodiment is described with reference to FIGS. 5 to 8.

As shown in FIG. 5, a walking shoe 21 is provided to receive the foot of the user. Conventionally, the shoe 21 comprises an outer sole assembly 22 and an upper 23 affixed to the sole assembly. The shoe extends lengthwise, along a longitudinal direction L, from a rear end 24 to a front end 25, and widthwise, along a transverse direction W, between a lateral side 26 and a medial side 27.

As shown, the upper 23 comprises a lower portion 30, provided to surround the foot, and has no upper portion. However, an upper may alternatively be provided to comprise both a lower portion and an upper portion, the latter being provided to surround the ankle and possibly a portion of the lower leg of the wearer.

According to the first embodiment being described, the shoe 21 extends heightwise from the bottom surface of the outer sole assembly 22 to an upper end 32, that is to say, up to the free end of the upper 23.

The shoe 22 is structured to allow smooth rolling movement of the foot during walking (for example, the shoe flexes at a flexion crease, such as at the metatarsophalangeal joint, as the heel is raised and lowered in relation to the toe), transmissions of sensory information, and impulses for supports or jump landings. This is why the outer sole assembly 22 and the upper 23 are relatively flexible.

As can be seen in FIGS. 6 and 7, the upper 23 comprises an outer shell 33 that includes an outer layer 34 and an inner layer 35. Each layer 34, 35, shown schematically, comprises the number of components necessary to carry out the desired function(s). This is described in more detail below.

As can be understood with reference to FIGS. 5 to 8, the outer layer 34 has a foot insertion opening 36 that has a rear division 37 and a front division 38, the front division extending in the direction of the shoe width, that is to say, along the transverse direction W, between a lateral edge 41 and a medial edge 42. The rear 37 and front 38 divisions are coextensive to facilitate the passage of the foot when putting on or taking off the shoe.

The shoe 21 further includes a device 43 for tightening the upper 23 by bringing the lateral edge 41 and medial edge 42 closer to one another. In a non-limiting manner, the upper tightening device 43 includes at least one lateral keeper 44, at least one medial keeper 45, and at least one linkage 46 running through the keepers 44, 45. The keepers are exemplary and can take any of a plurality of forms that include holes or eyelets through which a linkage or lace extends and structures around which the linkage or lace slides.

According to the invention, the inner layer 35 extends opposite the outer layer 34 (and in the illustrated embodiment they are in engagement with each other) and, in the area of the front division 38 of the foot insertion opening 36, between the lateral edge 41 and the medial edge 42. The inner layer 35 is impermeable to liquid. The inner layer 35 is flexible. And, in the direction of the shoe width, when the lateral edge 41 of the front division 38 and the medial edge 42 of the front division 38 of the outer layer 34 are brought closer to one another, the distance between the lateral edge 41 and medial edge 42 is shorter than the portion of the inner layer 35 extending in the area of the front division 38 of the foot insertion opening 36. Finally, a shoe according to the invention is simpler to manufacture and more comfortable, as has been explained above, than a shoe according to the prior art.

Still in the context of the invention, specific properties can be conferred on the inner layer 35, as described below.

According to a variation that is part of the first embodiment, the inner layer 35 is inextensible, which, for example, makes it easy to cut and thereby facilitates the manufacture. In another variation of the first embodiment the inner layer 35 is extensible, which can help the outer shell 4 to adapt even better to the shape of the foot. These are selective details that in no way change the context of the invention.

Still for the first embodiment, and in a non-limiting manner, the inner layer 35 of the outer shell 33 includes a membrane and a lining. These elements are not shown in detail in the drawing figures as they are well known to one having ordinary skill in the art. For example, the membrane is impermeable to liquid and permeable to gas. In other words, the membrane is breathable-waterproof, that is to say, it allows a gas, such as water vapor, to pass therethrough, but blocks the passage of a liquid, such as water. This improves the comfort of the foot. The membrane is made of polymeric materials such as polyolefin, polyethylene-propylene copolymer, polyethylene, terephthalate, polycaprolactone, polyvinyl fluoride, polybutylene terephthalate, polyester copolymer, polytetrafluoroethylene, or the like. For example, the membrane comprises a porous polytetrafluoroethylene sheet and a polyurethane layer. Further, and again without limitation, the thickness of the membrane is between 5.0 and 250 micrometers, for example. This reduced thickness contributes to making the inner layer 35 of the outer shell 33 flexible and light.

As shown more specifically to FIGS. 6 and 7, the outer shell 33 of the upper 23 includes a flexible flap 47 extending in the area of the front division 38 of the foot insertion opening 36. In fact, the flap 47 is arranged between the linkage of the tightening device 43 and the inner layer 35 of the outer shell 33. The flap preserves the inner layer 35 against a possible shearing effect that may be exerted by the linkage, particularly in the case of very intense use of the shoe. As described below, the flap 47 may carry out other functions.

An insert 48 is fitted between the inner layer 35 of the outer shell 33 and the flexible flap 47. This insert is for example made of a flexible synthetic foam block, which can be polyurethane foam, polyethylene vinyl acetate foam, or any suitable material known to one of ordinary skill in the art. Because it contributes to the distribution of stresses related to the action of the linkage 46 during tightening, the insert 48 further improves comfort during use of the shoe. The flap 47, in collaboration with the inner layer 35, thus carries out a function of maintaining the insert 48 in the area of the front division.

With reference more particularly to FIG. 6, when the lateral edge 41 and medial edge 42 of the front division 38 of the foot insertion opening 36 are brought closer to one another, for example by the action of the tightening device 43, the inner layer 35 forms a lateral fold 51 in the area of the lateral edge 41. Similarly, when the lateral edge 41 and medial edge 42 of the front division 38 of the foot insertion opening are brought closer to one another, the inner layer 35 forms a medial fold 52 in the area of the medial edge 42. It is thus understood that the central portion 53 of the inner layer 35, located in the area of the front division 38 of the foot insertion opening 36, becomes deformed at the same time as the lateral 41 and medial 42 edges are brought closer to one another. The central portion is actually capable of becoming deformed by folding in the manner of a bellows. In fact, the inner layer 35 is folded in the area of its central portion 53 when the upper is tightened. In this case, the fitting volume is reduced.

Conversely, with reference to FIG. 7, the inner layer 35 is unfolded in the area of its central portion 53 when the upper is loosened. In this case, the fitting volume is substantial. The tightening device 43 does not exert its tightening action, and the lateral edge 41 and medial edge 42 of the front division 38 of the foot insertion opening 36 are spaced apart.

As can also be seen in both FIG. 6 and in FIG. 7, the shoe 21 includes a lasting board 54. In a non-limitng manner, this lasting board is affixed to the upper 23 by a seam 55, in this case a Strobel-type seam. It can be said more precisely that the lasting board 54 is affixed to the outer shell 33 by the seam 55. The seam is not described in detail here as it is well known to one of ordinary skill in the art. Manufacturing the shoe 21 with a sewn lasting board, as opposed to an adhesively affixed lasting board, makes it possible to obtain a fitting volume that is closer to the shape of a foot. Advantageously, it follows that the shoe offers greater comfort, compared to what it would be an adhered lasting board.

As shown in FIG. 8, the inner layer 35 of the outer shell 33 is made in a single piece. This means that the inner layer extends over the entire upper 23. This does not prevent the inner layer 35 from including a plurality of thicknesses, as mentioned above, including a membrane and a lining. The inner layer 35 is generally V-shaped, having an opening angle β between 45 and 90 degrees. The inner layer 35 is assembled with the outer layer 34, which has the same overall appearance as the inner layer 35. However, the outer layer 34 has a notch 56, shown as a dotted line between the lateral 41 and medial 42 edges, for receiving the flexible flap 47, not shown in FIG. 8. Finally, the upper 23 is made from a generally V-shaped preform, having an opening angle β between 45 and 90 degrees. According to the invention, the elements forming the outer shell 33 are assembled flat. The shoe manufacturing process is thus simplified.

Other embodiments of the invention are described below with reference to FIGS. 9 and 10. For reasons of convenience, the elements shared with the first embodiment are designated by the same reference numerals.

According to the second embodiment, as can be seen in FIG. 9, the inner layer 35 of the outer shell 33 is an assembly of two portions 61, 62. This configuration makes it possible to optimize the cutting of material for the manufacture of the shoe. More specifically, the scraps of material generated by the cutting of plies are smaller. Given that the price per unit area is very high in the case of a membrane impermeable to water and permeable to gas, the resulting saving is substantial.

Still for the second embodiment, the portions 61, 62 are assembled with one another to assume the general appearance of the inner layer 35. The assembly is done via a combination of stitching and adhesively affixed strips, which are located in the area of the lateral side 26 and medial side 27 of the shoe 21. This location of seams and strips is outside of the zones of the upper that are subject to bending or to the action of the tightening device. As a result, foot comfort is preserved.

In the same spirit, according to the third embodiment, as can be seen in FIG. 10, the inner layer 35 of the outer shell 33 is an assembly of three portions 63, 64, 65. Here again, the configuration allows optimizing the cutting of material for the manufacture of the shoe, and the resulting saving is substantial.

Again, the portions 63, 64, 65 are assembled with one another to assume the general appearance of the inner layer 35. The assembly is done via a combination of stitching and adhesively affixed strips, which are located in the area of the lateral side 26, medial side 27, and rear end 24 of the shoe 21. This location of seams and strips is outside of the zones of the upper that are subject to bending or to the action of the tightening device. As a result, foot comfort is preserved.

In any case, the invention is made from materials and according to implementation techniques known to one of ordinary skill in the art.

The invention is not limited to the embodiments described above, and includes all technical equivalents that fall within the scope of the claims that follow.

For example, one can provide a configuration for which the outer layer 34 and inner layer 35 of the outer shell 33 are affixed to one another by glue dots 39, that is, by spots of glue spaced apart within the interface between the inner and outer layers of the outer shell. Glue dots 39 are shown in FIGS. 6 and 7, but are optional in the previously described embodiment. The glue dots improve the ability of the outer shell 33 to grip the foot evenly, while preserving its ability to block the intrusion of water and to allow gas to pass therethrough.

Generally speaking, the flexible flap 47 extends over an area between 80% and 100% of the front division 38 of the foot insertion opening 36. This optimizes the function of protecting the top of the foot. The flexible flap 47 also sometimes extends over an area greater than 100% of the front division 38 to obtain protection against obstacles, such as low hanging branches, in the area of the flexion crease.

Further, at least because the invention is disclosed herein in a manner that enables one to make and use it by virtue of the disclosure of particular exemplary embodiments, such as for simplicity or efficiency, for example, the invention can be practiced in the absence of any additional element or additional structure that is not specifically disclosed herein.

Claims

1. Flexible shoe comprising: a sole assembly;an upper extending upwardly from the sole assembly;the shoe extending: lengthwise from a rear end to a front end;widthwise between a lateral side and a medial side; andheightwise from the sole assembly to an upper end;the upper comprising: an outer shell comprising: an inner layer;an outer layer comprising a foot insertion opening that includes a rear division and a front division;the front division extending widthwise between a lateral edge and a medial edge of the foot-insertion opening;an upper-tightening-device configured to bring the lateral edge and medial edge closer to one another;the inner layer extending opposite the outer layer and in the area of the front division of the foot insertion opening, between, the lateral edge and the medial edge;the inner layer being a liquid-impermeable layer;the inner layer being a flexible layer; anda distance between the lateral edge and medial edge is shorter than the portion of the inner layer extending in the area of the front division of the foot insertion opening when the lateral edge and medial edge of the outer layer are brought closer to one another by the upper-tightening-device.

2. Shoe according to claim 1, wherein: the inner layer of the outer shell comprises a membrane and a lining.

3. Shoe according to claim 2, wherein: the membrane is impermeable to liquid and permeable to gas.

4. Shoe according to claim 2, wherein: the thickness of the membrane is between 5.0 and 250 micrometers.

5. Shoe according to claim 1, wherein: the outer shell of the upper comprises a flexible flap extending in the area of the front division of the foot insertion opening.

6. Shoe according to claim 5, wherein: an insert is fitted between the inner layer of the outer shell and the flexible flap.

7. Shoe according to claim 1, wherein: when the lateral edge and medial edge of the front division are brought closer to one another, the inner layer forms a fold in the area of the lateral edge.

8. Shoe according to claim 1, wherein: when the lateral edge and medial edge of the front division are brought closer to one another, the inner layer forms a fold in the area of the medial edge.

9. Shoe according to claim 1, further comprising: a lasting board.

10. Shoe according to claim 1, wherein: the tightening device comprises at least one lateral keeper, at least one medial keeper, and at least one linkage extending through the keepers.

11. Shoe according to claim 1, wherein: the inner layer of the outer shell is made in a single piece.

12. Shoe according to claim 1, wherein: the inner layer of the outer shell is an assembly of two portions.

13. Shoe according to claim 1, wherein: the inner layer of the outer shell is an assembly of three portions.

14. Shoe according to claim 1, wherein: the outer layer and inner layer of the outer shell are affixed to one another by glue dots.

15. Shoe according to claim 1, wherein: each of the outer sole and the upper has a flexible structure allowing the shoe to flex during use at a flexion crease of the shoe.