Shoe having a sole structure and an air pump device for blowing air into a shoe interior space

Abstract

A shoe has an air pump device comprising a bellows formed in a cavity in a heel area of the sole structure. The cavity has an average height of at least 4 mm and extends horizontally over most of the surface of the heel area, so that a support strip of the compressible material of the at least one intermediate layer remains between the cavity and the outside edges of the sole structure on the sides and at the heel, wherein the support strip extends vertically over the full height of the cavity and the average width of the support strip is not more than 20% of the maximum width of the heel area measured transversely to the walking direction. The compressible material has an average hardness between 30 and 55 Shore-A at least in the area of the support strip.

Claims

1. A shoe comprising a sole structure having a top side facing a shoe interior space, and an air pump device for blowing air into the shoe interior space, wherein the air pump device comprises: a bellows formed in a cavity in a heel area of the sole structure; an intake channel coupled to the bellows for transporting air to the bellows from an intake opening; and an air supply device coupled to the bellows for forwarding air from the bellows into the shoe interior space; wherein the sole structure has, at least in the heel area, a multilayer structure comprising: at least one cover layer comprising a layer of a bending stiff material arranged over the cavity; at least one intermediate layer of a compressible material, the intermediate layer containing the cavity; and at least one outsole layer arranged below the cavity; wherein the layer of the bending stiff material forms a bending stiff plate that overlaps the cavity; wherein the cavity extends horizontally over most of the surface of the heel area so that a support strip of the compressible material of the at one intermediate layer remains between the cavity and the outside edges of the sole structure on the sides and at the heel; wherein the support strip extends vertically over the full height of the cavity and the average width of the support strip is not more than 20% of the maximum width of the heel area measured transversely to the walking direction; wherein the cavity has an average height of at least 4 mm; and wherein the compressible material has an average hardness between 30 and 55 Shore-A at least in the area of the support strip.

2. The shoe according to claim 1, wherein the compressible material has an average hardness between 45 and 55 Shore-A.

3. The shoe according to claim 2, wherein the compressible material is a viscoelastic material which exhibits a recovery of at least 80% within a period of 0.3 s when a load thereon is abruptly removed entirely following a compression.

4. The shoe according to claim 3, wherein the bellows formed in the cavity of the sole structure comprises a bladder made from an elastic plastic material which is inserted in the cavity, wherein the intake channel comprises at least one first plastic pipe which opens into the bladder, and the air supply device comprises at least one second plastic pipe which is coupled to the bladder.

5. The shoe according to claim 3, wherein the compressible material exhibits a recovery of at least 90% within a period of 0.3 s when a load thereon is abruptly removed entirely following a compression.

6. The shoe according to claim 2, wherein a top side of the support strip comprises a wide support surface for the at least one cover layer, and a width of the support strip decreases downwardly starting from the wide support surface, wherein the inner surface of the support strip which borders the cavity recedes to the outside.

7. The shoe according to claim 6, wherein starting from the wide support surface the width of the support strip initially decreases strongly and then decreases less with increasing distance from the wide support surface, so that an interior surface is formed that arches outwards.

8. The shoe according to claim 2, wherein the bending stiff plate has a bending stiffness with which a force of 1000 N acting on a middle of the bending stiff plate that is supported at its edges causes a deflection of not more than 10% of the width of the plate.

9. The shoe according to claim 1, wherein the cavity has an average height of at least 6 mm.

10. The shoe according to claim 1, wherein the compressible material is a viscoelastic material which exhibits a recovery of at least 80% within a period of 0.3 s when a load thereon is abruptly removed entirely following a compression.

11. The shoe according to claim 10, wherein the compressible material exhibits a recovery of at least 90% within a period of 0.3 s when a load thereon is abruptly removed entirely following a compression.

12. The shoe according to claim 10, wherein a top side of the support strip comprises a wide support surface for the at least one cover layer, and a width of the support strip decreases downwardly starting from the wide support surface, wherein the inner surface of the support strip which borders the cavity recedes to the outside.

13. The shoe according to claim 12, wherein starting from the wide support surface the width of the support strip initially decreases strongly and then decreases less with increasing distance from the support surface, so that an interior surface is formed that arches outwards.

14. The shoe according to claim 12, wherein the bending stiff plate has a bending stiffness with which a force of 1000 N acting on a middle of the bending stiff plate that is supported at its edges causes a deflection of not more than 10% of the width of the plate.

15. The shoe according to claim 10, wherein the bending stiff plate has a bending stiffness with which a force of 1000 N acting on a middle of the bending stiff plate that is supported at its edges causes a deflection of not more than 10% of the width of the plate.

16. The shoe according to claim 1, wherein a top side of the support strip comprises a wide support surface for the at least one cover layer, and a width of the support strip decreases downwardly starting from the wide support surface, wherein the inner surface of the support strip which borders the cavity recedes to the outside.

17. The shoe according to claim 16, wherein the width of the wide support surface is in the range between 9 mm and 18 mm, wherein a smaller value for the width of the wide support surface for smaller shoe sizes and a larger value for the width of the wide support surface for larger shoe sizes is preferred.

18. The shoe according to claim 17, wherein the bellows formed in the cavity of the sole structure comprises a bladder made from an elastic plastic material which is inserted in the cavity, wherein the intake channel comprises at least one first plastic pipe which opens into the bladder, and the air supply device comprises at least one second plastic pipe which is coupled to the bladder.

19. The shoe according to claim 16, wherein the bending stiff plate has a bending stiffness with which a force of 1000 N acting on a middle of the bending stiff plate that is supported at its edges causes a deflection of not more than 10% of the width of the plate.

20. The shoe according to claim 19, wherein the outsole layer arranged below the cavity and parts of the intermediate layer arranged between the cavity and the outsole layer protrude downwards, so that the cavity is extended downwards.

21. The shoe according to claim 16, wherein starting from the wide support surface a width of the support strip initially decreases strongly and then decreases less with increasing distance from the support surface, so that an interior surface is formed that arches outwards.

22. The shoe according to claim 16, wherein the bending stiff plate has a bending stiffness with which a force of 1000 N acting on a middle of the bending stiff plate that is supported at its edges causes a deflection of not more than 10% of the width of the plate.

23. The shoe according to claim 1, wherein the bending stiff plate has a bending stiffness with which a force of 1000 N acting on a middle of the bending stiff plate that is supported at its edges causes a deflection of not more than 10% of the width of the plate.

24. The shoe according to claim 23, wherein the outsole layer arranged below the cavity and, if present, the parts of the intermediate layer arranged between the cavity and the outsole layer protrude downwards, so that the cavity is extended downwards.

25. The shoe according to claim 1, wherein the bellows formed in the cavity of the sole structure comprises a bladder made from an elastic plastic material which is inserted in the cavity, wherein the intake channel comprises at least one first plastic pipe which opens into the bladder, and the air supply device comprises at least one second plastic pipe which is coupled to the bladder.

26. The shoe according to claim 1, wherein the outsole layer arranged below the cavity and parts of the intermediate layer arranged between the cavity and the outsole layer protrude downwards, so that the cavity is extended downwards.

27. The shoe according to claim 1, wherein the intake channel coupled to the bellows for transporting air from an intake opening to the bellows has a minimum cross sectional area of 3 mm.sup.2, for shoe sizes longer than about 25 cm a minimum cross sectional area of 4 mm.sup.2.

28. The shoe according to claim 1, wherein the cover layer over the layer of bending stiff material comprises a cushion layer made from a softer material and/or a cover sole with a layer that has been adapted on top to the shape of the heel.

29. The shoe according to claim 1, wherein the bellows formed in the cavity of the sole structure comprises a bladder made from an elastic plastic material which is inserted in the cavity, wherein the intake channel comprises at least one first plastic pipe which opens into the bladder, and the air supply device comprises at least one second plastic pipe which is coupled to the bladder.

30. The shoe according to claim 29, wherein the bladder, the at least one first plastic pipe and the at least one second plastic pipe are manufactured as a single part from the elastic plastic material and inserted in the cavity in the at least one intermediate layer of the compressible material.

31. The shoe according to claim 29, wherein straight and/or curved bending rods are arranged inside the bladder and are fastened to the wall of the bladder adjacent to the top side of the cavity and to the wall of the bladder adjacent to the bottom side of the cavity in such manner that they are inclined relative to the horizontal, and the bending rods are deformed elastically when the bladder is squeezed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, the invention will be explained in greater detail with reference to preferred embodiments represented in the drawing. In the drawing:

(2) FIG. 1 is a diagrammatic side view of a shoe according to the invention with a sole structure and air pump device;

(3) FIG. 2 is a diagrammatic cross section through the heel area of the shoe along plane A-A of FIG. 1;

(4) FIG. 3 is a diagrammatic cross section through the heel area of an alternative embodiment; and

(5) FIG. 4 is a diagrammatic cross section in the longitudinal direction of the shoe through a bladder in an embodiment that includes bending rods inside the bladder.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

(6) FIG. 1 is a diagrammatic side view of a shoe 1 according to an embodiment of the invention. Shoe 1 comprises an upper 2 and a sole structure 3, the top side 4 of which faces into the interior space of shoe 1. For the purpose of the description of the present invention, all components of the shoe that are located between the interior space of shoes 1 and the underside of an outsole that comes into contact with the ground are considered to be components of the sole structure. This definition must be stated explicitly here because parts of this sole structure, particularly the insole, can be considered part of the upper for manufacturing purposes. Sole structure 3 is sometimes also called the floor of the shoe. In the shoe 1 according to the invention shown in FIG. 1, sole structure 3 comprises (from bottom to top) an outsole layer 5, an intermediate layer 6 and a cover layer 7. Each of these layers may themselves comprise several components, particularly several layers. In an embodiment not shown in FIG. 1, outsole layer 5 and intermediate layer 6 may be designed from the same material and even produced as a single part. Preferably, however, outsole layer 5 and intermediate layer 6 comprises different materials, wherein the material is chosen with a view to the function of the respective layers.

(7) The shoe according to the invention is equipped with an air pump device for blowing air into the interior space of the shoe. The air that is blown into the interior space of the shoe is preferably sucked in through an opening in the outside of the shoe, so that fresh air can be supplied to the interior space of the shoe. In a less preferred alternative embodiment, the air that is blown into the interior space of the shoe can also be sucked in at a site in the interior space of the shoe which is closer to the foot opening (that is to say, the upper opening into the interior space of the shoe) than the openings through which the air is blown into the interior space. The air pump device has a bellows formed in cavity in a heel area of the sole structure, an intake channel coupled to the bellows for transporting air from the intake opening into the bellows, and an air supply device coupled to the bellows for forwarding air from the bellows to the interior space of the shoe.

(8) In the embodiment shown in FIG. 1, the intake channel 11 comprises a tubular line that opens into cavity 10 and is routed upwards from intermediate layer 6 in the heel area along upper 2 in such manner that intake opening 12 is positioned above sole structure 3. The higher intake opening 12 is positioned, the less risk there is that dust and moisture stirred up from the ground will be sucked in with the air by the air pump device. In the preferred embodiment represented schematically in FIG. 1, intake channel 11 is mostly accommodated in a plastic component that is coupled to sole structure 3, which component is fastened to the back of upper 2. In alternative embodiments, the plastic component may also be routed inside upper 2, between an outer upper element and an inner upper element (lining). In the latter case, intake opening 12 may also be located on the top border of the upper, that is to say on the foot opening. In other embodiments, intake channel 11 may also be formed in an air supply device on the side of the shoe, as is described in EP 2 772 151 A1 for example. Intake channel 11 may also comprise multiple tubes or pipes that transport the air from intake openings to cavity 10, which may be conformed at various positions on the shoe. Air supply device 13 may also include one or more channels or conduits that open into cavity 10. The channels of air supply device 13 that lead away from cavity 10 may open into openings on top side 4 of sole structure 3. In one embodiment, the air leaving from cavity 10 is first forced into a channel of air supply device 13. The channel then branches into a plurality of smaller channels, which in turn then end at openings on the top side of intermediate sole 6. A cover layer placed over intermediate sole 6 consists for example of an insole which also has passthrough openings at the locations where the channels on the top side of the intermediate layer end, which then open into the interior space of the shoe. If cover layer 7 comprises multiple layers arranged one on top of the other, including the insole, each of these layers has openings that correspond with each other, and which serve to connect air supply device 13 with the interior space of the shoe. Embodiments are also conceivable in which intake channel 11 and air supply device 13 are not coupled to separate openings in the cavity but are each coupled to a collector line, which opens into cavity 10 at one opening. A valve is located at the point where the collector line branches into the intake channel and the air supply device, and said valve may either provide the connection between the collector line and the intake channel or between the collector line and the air supply device depending on the pressure conditions (compression or expansion) prevailing in the cavity and the collector line. In addition, further embodiments are conceivable in which the air supply device comprises a line that connects cavity 10 in heel area 9 with a manifold cavity located under the ball or toe area in intermediate layer 6 and/or cover layer 7, wherein this manifold cavity is filled for example with an open-pored material or an air-permeable, wide-meshed but mechanically stable tissue or fleece, so that the air supplied via the line from cavity 10 is able to spread through the ball area inside the manifold cavity. The layers arranged over this manifold cavity then include passthrough holes, from which the air that is distributed in the manifold cavity exits into the interior space of the shoe. Such an arrangement is known from EP 2 218 348 A1 for example.

(9) In the shoe according to the invention, of which a preferred embodiment is represented schematically in FIG. 1, at least in heel area 9 sole structure 3 has a multilayer structure comprising at least outsole layer 5, intermediate layer 6 made from a compressible material, and a cover layer that comprises a layer of bending stiff material arranged over cavity 10. The layer of bending stiff material forms a bending stiff plate 8 that covers cavity 10. Stiff plate 8 in the embodiment according to FIG. 1 overlaps cavity 10 and is formed only in heel area 9. In alternative embodiments the stiff plate may also extend beyond heel area 9. Cover layer 7 may comprise multiple layers, of which one is the layer of bending stiff material. In other embodiments, cover layer 7 may also consist entirely of bending stiff material. In preferred embodiments, cover layer 7 comprises the insole. In other embodiments, the insole may be arranged over a separate layer of bending stiff material, which constitutes the bending stiff plate.

(10) FIG. 2 shows a diagrammatic cross section through the sole structure along plane A-A according to FIG. 1. In this embodiment, sole structure 3 comprises an outsole layer 5, which includes a bulge 18 below cavity 10 of such kind that the outsole layer protrudes downwards and cavity 10 is enlarged. Sole structure 3 further comprises an intermediate layer 6 made from a compressible material. Cavity 10 extends horizontally over most of the surface of heel area 9, with the result that a support strip 16 of the compressible material of the intermediate layer (or also the compressible material of multiple intermediate layers arranged one on top of the othernot shown in FIG. 2) remains between cavity 10 and the outside edges on the side and heel areas of sole structure 3. FIG. 2 shows a cross section through the side sections of support strip 16. Strip 16 extends vertically over the full height of cavity 10. The average width of support strip 16 is not more than 20% of the maximum width of heel area 9, measured transversely to the walking direction. In a preferred embodiment, the average strip width is equal to about 14-17% of the maximum width of the heel area transversely to the walking direction. In the embodiment shown in FIG. 2, top side 23 of cavity 10 is formed by the underside of cover layer 7, and bottom side 24 of cavity 10 is formed by the top side of outsole layer 5.

(11) The compressible material of intermediate layer 6 (orin other embodimentsthe compressible materials of the intermediate layers) has an average hardness between 30 and 55 Shore-A at least in the region of support strip 16. Preferably, it has an average hardness between 45 and 55 Shore-A. In preferred embodiments, the compressible material is a viscoelastic plastic material which in the event of a complete removal of load abruptly following a compression (sudden raising of the foot off the ground) exhibits a recovery of at least 80%, preferably at least 90% within a period of 0.3 s. A period of 0.3 s was chosen as a reference time for recovery because this time approximately corresponds to the time that is for expansion in a fast step frequency. The compressible material for the intermediate layer is preferably chosen from polyurethane foam, ethylvinyl acetate (EVA) orpreferablyexpanded thermoplastic polyurethane (eTPU) with closed-cell foam. In one embodiment, the intermediate layer comprises a polyurethane foam having a density between 0.45 and 0.5 g/cm.sup.3. A plastic of which the deformation remains practically entirely reversible even after a large number of loading and unloading cycles is preferred. An expanded thermoplastic polyurethane (eTPU) with high recovery capability, and which has high rebound elasticity with a rebound height greater than 45% (measured in a ball rebound test according to DIN EN ISO 8307) is particularly preferred.

(12) In the embodiment shown in FIG. 2, cover layer 7 comprises a bending stiff plate 8 consisting of a bending stiff material which is positioned over a support surface 17 of support strip 16 of intermediate layer 6, and an insole 15 arranged over this, which insole is coupled to the material of upper 2 (at a lasting margin 21, for example). The layer of rigid material that forms bending stiff plate 8 is preferably bonded to contact area 17 of support strip 16 with adhesive. Insole 15 is bonded adhesively to stiff plate 8. Various embodiments for joining insole 15 to upper 2 are possible, but these are not so important in the context of the present invention. For example, insole 15 may be bonded to the material of upper 2 in a region where the materials lie flat against one another (lasting margin 21). The material of the upper is stitched to the material of the insole by a special method known as the Strobel method, which is not shown. A cover sole (not shown in FIG. 2) may be arranged over insole 15 as a further component of cover layer 7. Cover sole may comprise a cushion layer made from a soft material and/or a layer whose top side is conformed to the shape of the heel.

(13) FIG. 3 is a diagrammatic representation of an alternative embodiment of sole structure 3. Outsole layer 5 including bulge 18 and support strips 16 of intermediate layer 6 are constructed as in the embodiment of FIG. 2. In the embodiment shown in FIG. 3, the air pump device comprises a bladder 20 made from an elastic plastic material, which substantially fills cavity 10. In this embodiment, bladder 20 lies on the top side of outsole layer 5, on the inner walls of support strips 16 and the underside of cover layer 7. Bending stiff plate 8 of cover layer 7 is formed by insole 15 itself. The material of upper 2 is for example bonded adhesively to the underside of insole 15, wherein the composite structure of upper 2 and insole 15 is bonded adhesively to intermediate layer 6, that is to say to the support areas 17 of strip 16 of intermediate layer 6 in heel area 9. A cover sole 19 made from a soft material is arranged over insole 15. FIG. 3 is merely a diagrammatic representation which provides a simplified illustration of the bond between upper 2 and insole 15. In fact, insole 15 and the material of upper 2 are usually bonded to each other adhesively with the aid of a device called a lasting margin, as is represented in FIG. 2.

(14) In the embodiments shown in FIGS. 2 and 3, cavity 10 extends over the entire height of intermediate layer 6 in heel area 9. But other embodiments are also imaginable in which the material of intermediate layer 6 (or of one of several intermediate layers) may also be arranged above cavity 10 and below cover layer 7 and/or below cavity 10 and above outsole layer 5. This may be the case particularly when multiple intermediate layers are provided.

(15) In a preferred embodiment, particularly an embodiment that uses the bladder 20 shown in FIG. 3, straight and/or curved bending rods may be arranged in cavity 10 between top side 23 and bottom side 24 of cavity 10, which rods are coupled to the material adjacent to top side 23 and bottom side 24 in such a way that they are inclined with respect to the horizontal, wherein the bending rods are deformed elastically when cavity 10 is compressed.

(16) FIG. 4 illustrates an embodiment in which bending rods 22 are arranged inside a bladder 20 that fills a cavity 10. In this diagrammatic cross sectional representation, for the sake of simplicity only two bending rods 22 are shown, of which one (cross-hatched) bending rod 22 is positioned in the section plane and the other is behind the section plane. Bending rods 22 preferably comprise the material of the bladder, that is to say an elastic plastic. They are coupled to the wall of bladder 20 in such manner that they are aligned at an angle to the horizontal. In the diagrammatically represented embodiment, bending rods 22 are not straight but curved, so that they are deformed in a certain, predetermined way when cavity 10 and therewith bladder 20 is compressed.

(17) Many alternative embodiments are conceivable within the scope of the inventive thought. For example, two or more bladders, each with associated suction channels and air supply devices may be provided in cavity 10, or cavity 10 may be divided by partitions into two of more sub-cavities, each with associated suction channels and air supply devices.