METHOD FOR PRODUCING A SHOE SOLE

Abstract

A shoe includes a sole structure that defines a first supporting structure, a second supporting structure, and a third supporting structure, the first supporting structure being disposed within a forefoot region, the second supporting structure being disposed within a midfoot region, and the third supporting structure being disposed within a heel region. Each of the first supporting structure, the second supporting structure, and the third supporting structure define at least one curved surface, against which a plurality of plastic bodies are disposed. The plurality of plastic bodies comprise foamed plastic, define spheres or ellipsoids, are between 1 mm and 13 mm in the three spatial directions, and are arranged loosely within the sole structure without connection to one another. The plurality of plastic bodies are compressed against the first supporting structure, the second supporting structure, and the third supporting structure.

Claims

1. A shoe, comprising: a sole structure defining a first supporting structure, a second supporting structure, and a third supporting structure, the first supporting structure being disposed within a forefoot region, the second supporting structure being disposed within a midfoot region, and the third supporting structure being disposed within a heel region, wherein each of the first supporting structure, the second supporting structure, and the third supporting structure define at least one curved surface, against which a plurality of plastic bodies are disposed, wherein the plurality of plastic bodies comprise foamed plastic, define spheres or ellipsoids, are between 1 mm and 13 mm in the three spatial directions, and are arranged loosely within the sole structure without connection to one another, and wherein the plurality of plastic bodies are compressed against the first supporting structure, the second supporting structure, and the third supporting structure.

2. The shoe of claim 1, wherein each of the first supporting structure, the second supporting structure, and the third supporting structure defines a longitudinal axis, and wherein the at least one curved surface of each of the first supporting structure, the second supporting structure, and the third supporting structure includes a first curved surface on a first side of the longitudinal axis, and a second curved surface on a second side of the longitudinal axis, opposite the first side.

3. The shoe of claim 2, wherein the first curved surface and the second curved surface are joined at a peak.

4. The shoe of claim 1, wherein at least a portion of each of the first supporting structure, the second supporting structure, and the third supporting structure is integrally formed with a bottom wall of the sole structure.

5. The shoe of claim 1, wherein the plurality of plastic bodies are provided between a toe end of the sole structure and the first support structure, between the first support structure and the second support structure, between the second support structure and the third support structure, and between the third support structure and a heel end of the sole structure.

6. The shoe of claim 1, wherein the second supporting structure is disposed at a midpoint between the first supporting structure and the third supporting structure.

7. The shoe of claim 1, wherein each of the first supporting structure, the second supporting structure, and the third supporting structure define an upper wall and a bottom wall, and wherein the at least one curved surface is defined by the upper wall.

8. The shoe of claim 1, wherein the plurality of plastic bodies are selected from the group consisting of expanded thermoplastic polyurethane, expanded thermoplastic elastomer, and expanded polypropylene.

9. A shoe, comprising: a sole structure defining a hollow body and including a first supporting structure, a second supporting structure, and a third supporting structure, the first supporting structure being disposed within a forefoot region, the second supporting structure being disposed within a midfoot region, and the third supporting structure being disposed between a heel end of the sole structure and the second supporting structure, wherein each of the first supporting structure, the second supporting structure, and the third supporting structure defines a longitudinal axis with a first curved surface being disposed on a first side of the longitudinal axis and a second curved surface being disposed on a second side of the longitudinal axis, wherein a plurality of plastic bodies are compressed against each of the first curved surfaces and the second curved surfaces, wherein each of the plurality of plastic bodies is loosely arranged within the sole structure, and wherein the plurality of plastic bodies comprise foamed plastic, define spheres or ellipsoids, and are selected from the group consisting of expanded thermoplastic polyurethane, expanded thermoplastic elastomer, and expanded polypropylene.

10. The shoe of claim 9, wherein the first curved surface and the second curved surface are joined at a peak and the longitudinal axis extends through the peak.

11. The shoe of claim 10, wherein the plurality of plastic bodies are provided between a toe end of the sole structure and the first support structure, between the first support structure and the second support structure, between the second support structure and the third support structure, and between the third support structure and the heel end of the sole structure.

12. The shoe of claim 10, wherein at least a portion of each of the first supporting structure, the second supporting structure, and the third supporting structure is integrally formed with a bottom wall of the sole structure.

13. The shoe of claim 9, wherein the first supporting structure is disposed entirely within the forefoot region, the second supporting structure is disposed entirely within the midfoot region, and the third supporting structure is disposed within a heel region of the sole structure.

14. The shoe of claim 9, wherein the second supporting structure is disposed at a midpoint between the first supporting structure and the third supporting structure.

15. A shoe, comprising: a sole structure defining a first supporting structure, a second supporting structure, and a third supporting structure, the first supporting structure being disposed within a forefoot region, the second supporting structure being disposed within a midfoot region, and the third supporting structure being disposed within a heel region of the sole structure, wherein each of the first supporting structure, the second supporting structure, and the third supporting structure extend from a bottom wall of a sole structure toward an upper, and define a curved surface, wherein a plurality of plastic bodies are compressed against the curved surface, wherein the plurality of plastic bodies comprise foamed plastic, define spheres or ellipsoids, are between 1 mm and 13 mm in the three spatial directions, and are arranged loosely within the sole structure without connection to one another, and wherein the plurality of plastic bodies are compressed against the first supporting structure, the second supporting structure, and the third supporting structure.

16. The shoe of claim 15, wherein each of the first supporting structure, the second supporting structure, and the third supporting structure defines a longitudinal axis, and wherein the curved surface of each of the first supporting structure, the second supporting structure, and the third supporting structure includes a first curved surface on a first side of the longitudinal axis, and a second curved surface on a second side of the longitudinal axis, opposite the first side.

17. The shoe of claim 15, wherein the plurality of plastic bodies are provided between a toe end of the sole structure and the first support structure, between the first support structure and the second support structure, between the second support structure and the third support structure, and between the third support structure and a heel end of the sole structure.

18. The shoe of claim 15, wherein the first supporting structure is disposed entirely within the forefoot region and the second supporting structure is disposed entirely within the midfoot region.

19. The shoe of claim 15, wherein the second supporting structure is disposed at a midpoint between the first supporting structure and the third supporting structure.

20. The shoe of claim 15, wherein at least a portion of each of the first supporting structure, the second supporting structure, and the third supporting structure is integrally formed with a bottom wall of the sole structure.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0033] In the drawing an embodiment of the invention is shown.

[0034] FIG. 1 shows schematically a first process step of the production of a shoe sole according to the invention,

[0035] FIG. 2 shows the top plan view onto the shoe sole after carrying out the process step according to FIG. 1, wherein the sole hollow body of the shoe sole is not yet filled,

[0036] FIG. 3 shows schematically the subsequent process step at which the sole hollow body of the shoe sole is filled with plastic bodies and

[0037] FIG. 4 shows the section A-B according to FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

[0038] In FIG. 1 the start of the production process of a sole structure 20 of a shoe sole is shown schematically. An extruder 18 plasticizes plastic material and outputs the same via an extrusion head 17 so that a plastic hose 2 is produced which is closed around the whole circumference. When the same is long enough it is placed into a blow mold 3 which consists of two mold halves which are moved against another into the direction of the double arrow and then enclose the plastic hose 2 for blow molding in known manner.

[0039] As already mentioned alternatively an injection molding of a plastic blank can be taken in consideration which is then deformed in the blow mold 3.

[0040] By the blow molding process a sole hollow body 4 (see FIGS. 2 and 3) is produced which provides a reception space in its inner.

[0041] A first deformation tool 13 and a second deformation tool 15 are schematically indicated. Those tools 13, 15 are moved against another in the direction of the arrow when the mold halves of the blow mold 3 are closed. By the tools 13, 15 supporting structures 9 (see FIGS. 2 to 4) are formed into the sole hollow body 4.

[0042] A plurality of tools 13, 15 are provided although in FIG. 1 is shown only one single pair of tools 13, 15.

[0043] As can be seen from FIG. 2 a number of the mentioned supporting structures 9 have been produced presently which are described in detail below. For example, illustrated in FIGS. 2 and 3, a first supporting structure 9a can be formed in a forefoot region 21, a second supporting structure 9b can be formed in the midfoot region 22, and third supporting structure 9c can be formed in the heel region 23. Each supporting structure 9 can provide a supporting function at desired locations via the contact area of the foot on the surface of the shoe sole 1 so that at the application of the body weight of the wearer of the shoe the shoe sole 1 does not yield to the side in an uncontrolled manner.

[0044] Details of the supporting structure are apparent from FIG. 4. Here it can be seen that the sole hollow body 4 comprises an upper wall 5 and a bottom wall 6 which are arranged facing another with a distance after carrying out the blow molding process and enclose the mentioned hollow between another. By the deformation tools 13 and 15 recesses 7 and 8 are formed at those locations which are apparent from FIG. 2, namely by the first deformation tool 13 the recess 7 and by the second deformation tool 15 the recess 8.

[0045] Each of the supporting structures 9 defines a longitudinal axis 25 that extends through the upper wall 5 and intersects a closed end region 14 at a peak, illustrated, for example, in FIG. 4. As can be seen the recess 7 has a closed end region 14 and defines a first curved surface 26 on a first side of the longitudinal axis 25 and a second curved surface 27 on a second side of the longitudinal axis 25, as shown in the cross section of the shoe sole 1 of FIG. 4. The recess 8 has an opening by the second deformation tool 15 which is designed needle-shaped at its axial end. This opening is dimensioned in such a manner that the recess 7 with its closed end region 14 can at least partially enter into the same.

[0046] The supporting structure 9 which is produced in such a manner prevents respectively impedes a relative movement between the upper wall 5 and the bottom wall 6 in horizontal direction (at intended use of the shoe which has the mentioned shoe sole 1).

[0047] When the described sole hollow body 4 is completed insofar the hollow, which is contained in the same, is filled with plastic bodies 10. This is illustrated in FIG. 3. For this a filling nozzle 19 is inserted into an opening 11 in the sole hollow body 4. Then, via the filling nozzle 19 sphere-shaped or ellipsoid plastic bodies 10 made of expanded thermoplastic polyurethane (E-TPU) are filled, as the case may be supported by pressurized air, into the sole hollow body 4 between a toe end 28 and a heel end 29 of the sole hollow body 4 until the same is completely filled with plastic bodies 10 and the plastic bodies 10 are compressed against each supporting structure 9 (e.g., against the first curved surface 26 and the second curved surface 27). With respect to the material of the plastic bodies 10 hints to respective publications are already given above.

[0048] It is essential that the plastic bodies 10 are filled into the hollow of the sole hollow body 4 quasi as loose material and are placed in the hollow unconnected with another. Accordingly the plastic bodies 10 are free from any connection with another. The plastic bodies 10 indeed stabilize mutually after filling of the sole hollow body 4, but are arranged loosely to another.

[0049] Hereby not only the damping behavior of the sole and thus of the shoe can be influenced very beneficially; also the production process is easy and can be carried out cost-efficiently.

[0050] By the evacuation of air, i.e. by the application of a vacuum at a second opening 12 of the sole hollow body, the filling process can be supported and as the case may be after completion of the same air can be evacuated from the inner of the sole hollow body 4 (see arrow at the opening 12).

[0051] The openings 11 respectively 12 can be closed after completion of the filling process with plastic bodies 10. Here, especially a welding of the openings is taken in consideration. So, a hermitically closed hollow is created in the shoe sole 1 which is filled with the loosely arranged plastic bodies 10.

[0052] In cooperation with the supporting structure 9 the possibility is given to influence the spring and damping behaviors of the shoe sole in a certain range arbitrarily but to take care nevertheless that a good hold for the foot at good stability of the sole is given at the intended use of the shoe which is provided with the shoe sole.

[0053] In FIG. 2 also a preferred embodiment of the described process is illustrated: Here, a U-shaped insert 16 can be seen which is inserted prior to the closing of the blow mold 3 into the cavity of the same. By the blow molding process the insert 16 is firmly connected (welded) with the plastic hose 2 respectively the sole hollow body 4.

[0054] The insert 16 can be used to influence selectively the supporting function of the shoe sole 1. Preferably, the insert 16 is used as heel shell which supports the foot of the user of the shoe which is equipped with the shoe sole in the rear region and namely in the region of the heel.

[0055] 1 Shoe sole

[0056] 2 Plastic hose

[0057] 3 Blow mold

[0058] 4 Sole hollow body

[0059] 5 Wall

[0060] 6 Wall

[0061] 7 Recess

[0062] 8 Recess

[0063] 9 Supporting structure

[0064] 10 Plastic body

[0065] 11 First opening

[0066] 12 Second opening

[0067] 13 First deformation tool

[0068] 14 Closed end region

[0069] 15 Second deformation tool

[0070] 16 Insert

[0071] 17 Extrusion head

[0072] 18 Extruder

[0073] 19 Filling nozzle

[0074] 20 Sole structure

[0075] 21 Forefoot region

[0076] 22 Midfoot region

[0077] 23 Heel region

[0078] 25 Longitudinal axis

[0079] 26 First curved surface

[0080] 27 Second curved surface

[0081] 28 Toe end

[0082] 29 Heel end