US20050166422A1

US20050166422A1 - Shoe with an articulated spring-loaded outsole

Info

Publication number: US20050166422A1
Application number: US10/771,156
Authority: US
Inventors: Michael Schaeffer; Richard Ivester
Original assignee: Puma AG Rudolf Dassler Sport
Current assignee: Puma SE
Priority date: 2004-02-04
Filing date: 2004-02-04
Publication date: 2005-08-04

Abstract

Shoe (1), especially an athletic shoe, with a midsole (2) and an upper (3) connected to the midsole (2), the midsole (2) having a base body (2 a) which is connected to the upper (3), and a bottom plate (2 b). To improve the adjustability of the spring properties and/or the damping properties of the shoe sole, it is provided that at least one part (4, 5) of the bottom plate (2 b) is connected to the base body (2 a) by a hinge at an articulation point (7). Furthermore, at least one spring element (8) is provided between the side of the part (4, 5) of the bottom plate (2 b) facing the base body (2 a) and the side of the base body (2 a) facing the part (4, 5) of the bottom plate (2 b). Preferably, one spring is provided in the heel area and a plurality of springs are provided in the forefoot area.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The invention relates to a shoe, especially an athletic shoe, with a midsole and an upper connected to the midsole, the midsole being connected between a base body which is connected to the upper, and a bottom plate (outsole).
2. Description of the Related Art
A shoe of this type is known from published European Patent Application No. EP 0 552 994 B1 and corresponding U.S. Pat. No. 5,282,325. The upper is connected to the base body. While the midsole is connected to an outsole in the forward shoe area, the base body and the outsole diverge from one another in the shape of a wedge toward the end of the shoe. Between the base body and the outsole in the heel area a torsion spring is disposed between a pair of interior plates and the bottom plate can deflect relative to the outsole by compression of the spring. While the resiliency of the shoe sole can be influenced via a spring insert of this type, it is not possible to adjust the spring/damping properties with such an arrangement.

SUMMARY OF THE INVENTION

It is a primary object of the present invention is to provide a shoe, especially an athletic shoe and especially preferably a running shoe, such that it becomes possible to adjust the spring properties and/or the damping properties of the shoe sole in a manner as defined as possible and to adapt them to given boundary conditions as well as to change these properties if necessary.
Furthermore, it is a further object to make it possible to influence the stability of the shoe and especially of the sole in an improved manner.
These objects are achieved by the invention in that at least one part of the bottom plate is located by means of a hinge at an articulation point on the base body, between the side of the part of the bottom plate facing the base body and the side of the base body facing the part of the bottom plate there being at least one spring element.
Accordingly the shoe, especially the athletic shoe, therefore calls for a bottom plate which is articulated to the base body by means of a hinge, a spring element between the base body and the bottom plate influencing the spring and/or damping property of a midsole in a purposeful manner.
Preferably, the bottom plate has two parts which are coupled to the base body at the same articulation point.
The base body can be made in one piece and in the shape of a shell and/or plate. This is to be understood especially as the base body for the heel area of the shoe being made as a shell which in part three-dimensionally encompasses the heel of the wearer, while the base body in the forefoot area is made rather in the manner of a plate.
For articulated accommodation of the bottom plate on the base body, it is advantageously provided that the base body has at least one extension which has the shape of a crosspiece, which extends in the direction to the bottom plate, for forming the hinge and which has a hole to accommodate the bearing journal. The bearing journal can be formed by a screw which can be axially fixed with a nut. For stable execution of the hinge, it is preferably provided that the base body has two extensions which are located at a given distance and which are arranged on both sides and off-center relative to the lengthwise axis of the shoe.
At least one part of the bottom plate can be made as bent and/or curved plate which continuously widens in the direction of the articulation point at least over part of its extension transversely to the lengthwise axis of the shoe. Accordingly, most of the part of the bottom plate would be made essentially as a thin plate which according to the required shoe contour is bent or curved and which, moreover, becomes thicker in the direction to the articulation point.
The side of the bottom plate facing the ground can be provided with a conventional outer sole, especially with a rubber sole, and it can be both cemented separately onto the bottom plate and also can be directly injected-molded on.
The stability of the sole can be increased by the base body, on its side facing the bottom plate, bearing a guide element which interacts with an opposing guide element which is located on the side of the bottom plate facing the base body, the guide element and the opposing guide element, upon interaction, preventing or limiting the relative displacement of the base body and the bottom plate transversely relative to the lengthwise axis of the shoe. The guide element and the opposing guide element can be formed by crosspiece-like elevations which are located on the base body or on the bottom plate and which can be caused to engage one another such that relative displacement of the two parts transversely relative to the lengthwise axis of the shoe is prevented.
The execution of the spring element which is being used acquires major importance. It can have at least a cylindrical or prismatic shape in sections, circular and polygonal cross sectional shapes being also possible.
Preferably, the spring element or each spring element is formed of two sections which are connected to one another, the two sections being located coaxially with respect to one another and having a shape which is congruent to one another and a section in a profile perpendicular to a vertical line having smaller dimensions than the other section. When a force acts on the spring element, therefore when the sole is loaded by the weight of the wearer, one possible result is that the section which has been made with smaller dimensions, at least in part, enters the interior of the section which has been made with larger dimensions; accordingly the spring element which is made in this way works in the manner of a shock absorber (piston-cylinder system).
Furthermore, it can be provided that the two sections of the spring element are connected to one another via an elastic connecting section which extends only between the two sections.
It has proven especially effective when the two sections, in a profile perpendicular to the vertical, have a polygonal, especially a hexagonal shape. The two sections and the connecting section of the spring element are made in one piece according to one development.
With respect to the number and arrangement of the spring elements, it has proven advantageous for there to be a single spring element in the heel area between the base body and the bottom plate, preferably under the heel bone and the heel contact area. Here, there can be several, especially three spring elements, between the base body and the bottom plate in the forefoot area, preferably under the ball of the great toe, the ball of the little toe and in the toe region.
The spring elements can be cemented, welded, mechanically connected, or connected in situ (for example, by joint injection molding in the production process) to the base body and/or to the bottom plate.
Preferably, the articulation point of the hinge—viewed in the direction of the lengthwise axis of the shoe—is located in the area of the metatarsal bone, especially roughly in the area of the transition of the rear third of the length of the sole to its middle third.
To reliably hold the spring element in the base body or in the bottom plate, it can be provided that the base body and/or the bottom plate has at least one receiver for interlocking accommodation of the spring element.
Furthermore, the bottom plate can have recesses which are matched to the shape of the spring elements in a profile perpendicular to the vertical. In this way, it becomes possible to save weight, on the one hand, and on the other hand, the spring element can thus be made visible from underneath. These recesses can be re-filled with transparent plastic material.
In order to be able to influence the torsion and flexibility properties of the sole and to enable adjustment of them in a purposeful manner, it can be provided that at least part of the bottom plate has a slot or a groove which extends preferably over the entire thickness of the bottom plate. The slot can extend over at least two thirds of the length of the part of the bottom plate measured in the lengthwise direction of the shoe and runs roughly in the middle, essentially in the lengthwise direction of the shoe and zig-zag in the part. Furthermore, the slot can be filled with a material which is soft relative to the material of the part of the bottom plate.
With respect to the material of the sole components, it has proven effective when the base body and/or the bottom plate and/or the spring element are made of plastic, especially of a thermoplastic material, preferably of polyamide, polyurethane, polyethylene, polypropylene, polybutane, polyvinyl chloride or a mixture of at least two of these plastics. The plastic preferably has a Shore hardness between 75A and 65D; it can be transparent or translucent.
Here, it is especially preferred that the sole does not have any foamed plastic as is normally used for a midsole; therefore it is a foamless sole.
One embodiment of the invention is shown in the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an athletic shoe in accordance with an embodiment of the invention,
FIG. 2 is a bottom plan view of the bottom plate together with the hinge as seen viewed along line A-B in FIG. 1,
FIG. 3 is an exploded perspective view the base body together with the hinge, bottom plate and a spring element,
FIG. 4 is a perspective view of a spring element,
FIG. 5 is a sectional view of the spring element taken along line C-D in FIG. 4;
FIG. 6 is a perspective view of a rear foot bottom plate, and
FIG. 7 is a cross-sectional view taken along line E-F of FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a shoe 1 of the type which is used as a running shoe and which, as is conventional, has an upper 3. Underneath (for orientation, the direction of the upward vertical arrow V is shown) upper 3 is a midsole designated 2 as whole. Affixed to the underside of the midsole 2 is the outer sole 14, which is in the form of a rubber sole.
The midsole 2 is foamless, i.e., it does not have any foamed material, especially any foamed plastic materials, in contrast to a typical midsole which is formed entirely or to a substantial extent of foamed plastic material.
The midsole of the present invention is comprised of a base body 2 a which is permanently connected to the upper 3, and of a bottom plate 2 b which is located below the base body 2 a, to the underside of which the outer sole 14 is attached. The bottom plate 2 b, here, is formed of two parts 4, 5, specifically, a part 4 in the form of a rear foot bottom plate and a part 5 in the form of a forefoot bottom plate.
The two parts 4, 5 are articulated to the base body 2 a by means of a hinge 6 at an articulation point 7. For this purpose, a hinge 6 has a bearing journal 12 which is oriented perpendicular to the lengthwise axis 13 of the shoe 1.
The articulation point 7—viewed in the direction of the lengthwise axis 13 of the shoe 1—lies roughly in the area of the metatarsal bone, specifically roughly in the area of the transition of the rear third of the length of the midsole 2 to its middle third.
This configuration results in that, when the shoe 1 is being used, the parts 4, 5, depending on the loading of the shoe by the weight of the wearer, can pivot relative to the base body 2. The pivoting of these parts is determined by the spring elements 8 which are located between the base body 2 a and the parts 4, 5. At a given load on the shoe 1 or on the through sole 2 by the weight of the wearer, the spring and damping behavior of the spring elements 8 determines the extent of the pivoting motion of the parts 4, 5 relative to the base body 2 a.
In FIGS. 2 & 6, it can be recognized that there is a single spring element 8 in the rear foot area which is covered by the part 4. Here, only a single receiver 20 is shown which is matched to the outer cross sectional shape of the spring element 8 (in this case, the hexagonal shape of the spring element 8). As can be seen in FIG. 7, the receiver 20 has an elevation 27 which is round in cross section, which rises out of the base contour 28 of the rear part 4, and which in the interior has a shoulder 20 a and which is made according to the outside contour of the spring element 8. The spring element 8 can thus be inserted into the receiver 20 and is securely supported there on the shoulder 20 a, as indicated by the broken line illustration of a portion of spring element 8 in FIG. 7.
In the forefoot area which is covered by the part 5, there are three spring elements 8, for each of which a respective receiver 20 is provided. The receivers of the forefoot part 5 can be of the same construction as that described for the receiver 20 of the rear part 4.
As can be further seen, the parts 4, 5, have recesses 21 within the receivers 20 and which extend through the parts 4, 5. The recesses 21 make it possible for the spring element 8 to be viewed from underneath. The recesses 21 have a shape corresponding to the spring elements 8.
The torsion and flexibility properties of the midsole 2 can be influenced by a slot 22 which can likewise be seen in FIG. 2. The slot, in the illustrated embodiment, runs over a large part sole part 5 in the direction of the lengthwise axis 13, in a zig-zag or sinusoidal shape, roughly in the middle of the part 5. The slot 22 can also be refilled with a material which is softer than the material of the bottom plate 2 b; this enables exact adjustment of the torsion and flexibility properties of the midsole 2.
The interaction of the individual components of the midsole 2 is best discerned from FIG. 3. The base body 2 a is made shell-shaped in the rear area of the foot, therefore in the heel area, and encompasses the heel of the wearer three-dimensionally, by which the foot has good support there. In the forward area of the foot, the base body 2 a is made rather plate-shaped; it has only a slight curvature here which is matched to the contour of the foot in this area. In the area of the articulation point 7, therefore where the hinge 6 is located, the base body 2 a has two downward extensions 9, 10, which project downward over the base contour of the base body 2 a and have holes 11 which are used for passage of the bearing journal 12.
The two parts 4, 5 of the bottom plate 2 b are likewise largely plate-shaped, the plate thickness being roughly 2 to 7 millimeters. The parts 4, 5 are made slightly arched according to the ergonomics of the foot during rolling. The two parts 4, 5 thicken in the direction toward the articulation point 7. The hinge 6 is formed by bringing together the ends of the two parts 4, 5 with the two extensions 9, 10 of the base body 2 a. In doing so, the bearing journal 12 in the form of a screw passes through holes 23 in the part 4 of the bottom plate 2 b, through the holes 11 in the extensions 9, 10 and through the hole 24 in the part 5 of the bottom plate 2 b. As a result, the two extensions 9, 10 come to rest in the two receiving spaces 25 which are marked in FIG. 2. The bearing journal 12 is axially fixed with a nut 26.
As can be seen from a combined viewing of FIGS. 2 and 3, there is a guide element 15 which extends in the shape of a crosspiece on the base body 2 a and which interacts with an opposing guide element 16 which is located on the facing surface of part 5 of the bottom plate 2 b and is composed of two crosspieces which are located next to one another at a mutual spacing such that the guide element 15 can just enter between them. This results in that, when the two elements 15, 16 interact, any relative motion of the base body 2 a with respect to the part 5 of the bottom plate 2 b transversely to the direction of the lengthwise axis 13 of the shoe 1 is prevented or at least limited.
The execution of the spring elements 8 follows from FIGS. 4, 5. The spring elements 8 being used in the embodiment have a hexagonal outside contour having a lower section 17 and a section 18 located above it. The two sections 17, 18 are joined to one another via a connecting section 19. As can be seen especially from FIG. 5, the two sections 17, 18 and the connecting section 19 are made in one piece, i.e., the entire spring element 8 is preferably produced by a single injection molding process.
When the spring element 8 is loaded by the weight of the wearer of the shoe the loading force acts vertically on the element. The smaller upper section 18 dips into the interior of the lower section 17. The spring element 8 acts here in the manner of a piston and cylinder unit. Both the spring constant and also the damping properties of spring element 8 can be adjusted almost at will and can be matched to requirements by the geometrical dimensions (size, height, thickness of the sections 17, 18, 19) and by the choice of the material of the spring element 8. For the material of the spring elements 8, TPU with a Shore hardness between 70 and 95 A has proven effective.
The spring elements 8 can be held essentially interchangeably—optionally together with the bottom plate 2 b. By replacing the elements, the spring properties of the midsole 2 and its damping intensity can be adjusted. Furthermore, the stability of midsole 2, and thus of the shoe 1, can be influenced in this way.
While in the embodiment there is only a single spring element 8 in the rear foot area, i.e., in the area of the part 4 of the bottom plate 2 b, several, for example, two or three spring elements 8, can be housed here. The three illustrated spring elements have proven effective in the forefoot area, specifically one in the area of ball of the great toe, of the ball of the little toe and in toe region.
It is also possible for the spring elements 8 to be connected detachably or permanently to the base body 2 a or the bottom plate 2 b. For example, the techniques of cementing, welding, mechanical joining or joining in the production process (in situ) by joint injection molding are possible, as is a combination of these possibilities.
Furthermore, the spring elements 8 can be welded on the end on one or both sides so that an air cushion is formed in their interior. For a one-sided opening, they can lie in the direction of removal from the injection molding tool.
Another possibility which, however is not shown in the figures, is that there are several spring elements 8 which gradually become smaller in dimensions, interleaved in one another. As a result of the parallel connection of the interleaved spring elements high spring stiffness can thus be achieved; this enables better absorption of forces.
It can be seen in FIG. 1 that the part 5 of the bottom plate 2 b in the forward end area, therefore in the area of the tip of the foot, has contact with the base body 2 a. Since when the foot rolls, as a result of the deformation of the individual sole components, a relative change of the length of the base body 2 a and the bottom plate 2 b occurs, in this case, it is recommended that there be a movable guide between the base body 2 a and the bottom plate 2 b in the area of the tip of the foot in order to equalize the aforementioned relative change of length.
Alternatively or in addition, it can also be provided that the part 5 of the bottom plate 2 b in the hinge 6 be supported by means of an elongated hole so that the part 5 can move a small amount in the direction of the lengthwise axis 13 in order to equalize the changes of length. In this case, it is also easily possible, as an alternative configuration to the approach shown in FIG. 1, to provide a permanent connection between the base body 2 a and the part 5 of the bottom plate 2 b in the area of the tip of the foot.

Claims

1. Shoe, comprising:

an upper and

a midsole connected to the upper, the midsole having a base body which is connected to the upper and a bottom plate,

wherein at part of the bottom plate is connected by a hinge at an articulation point on the base body,

wherein at least one spring element is provided between a side of the part of the bottom plate facing the base body and the side of the base body facing the bottom plate.

2. Shoe as claimed in claim 1, wherein the bottom plate comprises two parts which are coupled to the base body at said articulation point.

3. Shoe as claimed in claim 1, wherein the base body is made in one piece and is at least partially in the shape of a shell or plate.

4. Shoe as claimed in claim 1, wherein the hinge comprises at least one extension on in the shape of a crosspiece which has a hole for accommodating a bearing journal.

5. Shoe as claimed in claim 4, wherein the bearing journal is formed by a screw which is axially fixed with a nut.

6. Shoe as claimed in claim 4, wherein the hinge has two extensions on the base body which are located at a given distance and which are arranged on both sides and off-center relative to the lengthwise axis of the shoe.

7. Shoe as claimed in claim 1, wherein at least part of the bottom plate is made formed by a curved plate which widens continuously in a direction toward the articulation point at least over part of the transverse extension of the shoe.

8. Shoe as claimed in claim 1, wherein a side of the bottom plate facing the ground an outer sole of resilient material provided thereon.

9. Shoe as claimed in claim 1, wherein the base body has a guide element on its side facing the bottom plate, the guide element being positioned relative to an opposing guide element on the side of the bottom plate facing the base body such that the guide element and the opposing guide element interact so as to at least limit relative displacement of the base body with respect to the bottom plate transversely with respect to the lengthwise axis of the shoe.

10. Shoe as claimed in claim 1, wherein the spring element, at least in sections, has a cylindrical or prismatic shape.

11. Shoe as claimed in claim 10, wherein the spring element has two sections which are connected to one another, the two sections being located coaxially relative to one another and having a shape which is congruent to one another with one section, in a profile perpendicular to a vertical line, having smaller dimensions than the other section.

12. Shoe as claimed in claim 11, wherein the section with smaller dimensions is able enter the interior of the section with larger dimensions, at least in part, when a force acts on the spring element.

13. Shoe as claimed in claim 11, wherein the two sections are connected to one another via an elastic connecting section which extends only between the two sections.

14. Shoe as claimed in claim 11, wherein the two sections in a profile perpendicular to a vertical line have a polygonal shape.

15. Shoe as claimed in claim 13, wherein the two sections and the connecting section are made in one piece.

16. Shoe as claimed in claim 1, wherein a single spring element is provided in the heel area between the base body and the bottom plate.

17. Shoe as claimed in claim 1, wherein a plurality of spring elements are provided in the forefoot area between the base body and the bottom plate.

18. Shoe as claimed in claim 1, wherein the spring elements are connected to at least one of the base body and the bottom plate by at least one of being cemented, welded, mechanically connected, and connected in situ.

19. Shoe as claimed in claim 1, wherein the articulation point, viewed in the direction of the lengthwise axis of the shoe, is located in the area of the metatarsal bone.

20. Shoe as claimed in claim 1, wherein at least one of the base body and the bottom plate has at least one receiver for interlocking accommodation of a respective spring element.

21. Shoe as claimed in claim 1, wherein the bottom plate has recesses which are matched to the shape of the spring elements in a profile perpendicular to a vertical line.

22. Shoe as claimed in claim 21, wherein the recesses are filled with a transparent plastic material.

23. Shoe as claimed in claim 1, wherein at least one part of the bottom plate has a slot or a groove which extends over the entire thickness of the bottom plate.

24. Shoe as claimed in claim 23, wherein the slot extends over at least two thirds of the length said at least one part of the bottom plate in the lengthwise direction of the shoe and runs roughly in the middle in the lengthwise direction of the shoe in a zig-zag or sinusoidal manner.

25. Shoe as claimed in claim 23, wherein the slot is filled with a material which is soft relative to the material of said at least one part of the bottom plate.

26. Shoe as claimed in claim 1, wherein at least one of the base body, the bottom plate and the spring element is made of plastic selected from the group consisting of polyamide, polyurethane, polyethylene, polypropylene, polybutane, polyvinyl chloride and a mixture of at least two thereof.

27. Shoe as claimed in claim 26, wherein the plastic has a Shore hardness between 75A and 65D.

28. Shoe as claimed in claim 26, wherein the plastic is transparent or translucent.

29. Shoe as claimed in claim 26, wherein the midsole is free of foamed plastic.