EP3829380B1 - Shoe with step-in aid and method for producing a shoe with step-in aid - Google Patents

Description

The invention relates to a shoe with an entry aid and a method for producing a shoe with an entry aid, wherein the shoe, on the one hand, automatically assumes an open state when a bending moment is exerted that is aimed at opening the shoe and, on the other hand, when a restoring moment is exerted that is directed at a Closing the shoe is directed, automatically assumes a closed state again.

The EP 1 443 834 B1 describes a shoe with a sole, an upper and a bistable element that defines a first and second stable state, the shoe having an open or closed state by the bistable element. The shoe can be transferred from the open to the closed state by stepping on it and can be easily opened by holding the heel with the other foot and pulling the foot up or by stepping on an edge, for example, while simultaneously arching the bistable element.

From the DE 2009 023 689 B4 , which is hereby incorporated by reference, a shoe is known which forms an opening and closing mechanism for the shoe through a bistable leaf spring arrangement, in which an actuating edge presses on the bistable leaf spring near its apex, so that even with slight deformation of the bistable leaf spring The switching process is initiated in the area of its apex, in which the insole bends around a bending point and the upper shoe or shoe shaft can be opened or closed. This makes it possible to get out of the shoe with little effort, while when the shoe is closed it is possible to walk safely without the shoe popping open.

An object of the invention is to provide a shoe with an entry aid and a manufacturing method for such a shoe, the shoe being optimized in such a way that it can have various common insoles, for example a solid insole that is glued or nailed to a lasted shaft, but also a soft insole that can be sewn to a shaft using a strobel seam. Another aspect of the task is to optimize the function and durability of a shoe with an entry aid.

The task is solved by the subjects of the independent claims. Advantageous refinements and further developments are the subject of the subclaims.

A shoe with an entry aid is specified, which includes an upper part with a shoe shaft and insole, a shoe sole and a bistable bending jump unit arranged in particular between the insole and the shoe sole.

The shoe upper, insole and shoe sole each have at least two parts that are movable relative to one another: The shoe upper has a shaft-heel part and shaft-front part, which are movable relative to one another; the insole also has an insole heel part and an insole front part, which are movable relative to one another at a bending point; and finally the shoe sole also has a sole-heel part and a sole-front part, which are movable relative to one another at a bending point. The shoe upper, insole and/or shoe sole can each be designed in two parts, in which the bending point is designed as a distance, or can be designed in one piece, in which the bending point is designed as a flexible material.

In the area of the bending point of the insole and at the same time in the area of the bending point of the shoe sole, in particular between the insole and the shoe sole, there is a bistable bending jump unit with a bistable leaf spring set up to switch between two stable states and a housing that at least partially surrounds the leaf spring.

A first triggering means is arranged on the housing of the bending jump unit in such a way that it exerts pressure on a first side of the leaf spring when a bending moment acts on the bending jump unit in order to trigger the leaf spring to jump over, so that the bending jump unit jumps from a stable first state to a stable second state goes over and puts the shoe in an open state.

In addition, a second triggering means is arranged on the housing of the bending jump unit in such a way that, when the restoring moment acts on the bending jump unit and is opposite to the bending moment, it exerts pressure on a second side of the leaf spring opposite the first side in order to trigger the leaf spring to jump over, so that the Bending jump unit returns abruptly from the stable second state to the stable first state and puts the shoe into a closed state.

The term bistable leaf spring refers in particular to any bistable element that can switch between two stable states by exerting pressure on opposite sides of the bistable element.

With the bistable bending jump unit, on the housing of which both a first and a second triggering means are arranged, an independent opening and closing mechanism for a shoe is formed, which is compatible with solid insoles that can be glued or nailed to a lasted shaft, as well as with soft insoles, which can be sewn to a shaft using a strobel seam. While in a solid insole the bending point can be designed, for example, as a gap or as a bridging elastically deformable material, a soft insole can be designed in one piece and form the bending point through its own flexibility. In other words, the insole can be designed to be completely flexible and therefore not have any hard and/or stiff material.

The bistable bending jump unit arranged between the insole and the shoe sole is advantageously designed as a separate component which has triggering means for allowing the leaf spring to jump over both the bending direction and the reverse restoring direction. The bending jump unit can advantageously be attached as a separate component to both a solid and a soft insole. In particular, the bending jump unit is shorter than the insole with respect to the longitudinal direction of the shoe and can be attached to the insole from below in the area of the bending point. The bending jump unit can, for example, have a length with respect to the longitudinal direction of the shoe that is less than three quarters of the length of the shoe or less than two thirds of the length of the shoe or even less than half the length of the shoe.

In order to arrange the bistable bending jump unit between the insole and the shoe sole, a recess can be provided in the shoe sole, which serves to accommodate the bistable bending jump unit. In the case of a one-piece shoe sole, the recess can extend into both the heel part of the sole and the front part of the sole. In this case can There is a thinned sole area below the recess, for example where the usual shoe heel ends, which forms the bending point between the sole-heel part and the sole front part. In the case of a two-part shoe sole, in which the sole-heel part and sole front part are completely separated from one another, recesses can be provided in both the sole-heel part and in the sole front part, which each partially accommodate the bending jump unit.

Increased comfort can also be achieved with the housing, which at least partially surrounds the leaf spring on both sides. In particular, the housing can have a damping effect and/or can additionally be provided with a damping material from the outside, so that the wearer of the shoe is less likely to notice the leaf spring flipping over.

The housing of the bending jump unit preferably comprises a rear housing part and a front housing part, wherein the two housing parts can be designed to be identical and/or symmetrical. A first and a second triggering means are arranged on both the rear and the front housing part. The two housing parts are movable relative to one another, in particular by the action of the bending moment or the restoring moment, preferably in a hinge-like manner at a gap which forms a distance between the two housing parts.

Preferably, the housing of the bending jump unit forms the first triggering means and/or the second triggering means integrally, preferably as an edge of the housing. In other words, the housing and triggering means are preferably formed in one piece and made of the same material. In the case of a housing with a rear and a front housing part, the rear and front housing parts in particular form a first and/or a second triggering means integrally, preferably as edges of the housing, which preferably face the gap.

The housing of the bending jump unit preferably forms an opening for receiving the leaf spring with a circumferential, preferably integral, i.e. one-piece, wall. The circumferential wall has a first wall section on the first side of the leaf spring and an opposite second wall section on the second side of the leaf spring, the first and second wall sections being the first and second, respectively Have or form triggering means, preferably as the inner edge of the wall. In particular, the first and second wall sections are connected to one another via side wall sections. In the case of a housing with a rear and a front housing part, in particular the rear housing part and the front housing part each form openings with such a wall facing one another and preferably towards the gap for receiving the leaf spring.

The leaf spring of the bending jump unit preferably has a plate-like end, which is held in a form-fitting manner in a socket section of the housing that is preferably facing away from the opening of the housing. In a housing with a rear and a front housing part, the leaf spring has in particular two plate-like ends, which are each held in a form-fitting manner in a socket section of the rear or front housing part, preferably facing away from the opening and the gap.

The leaf spring of the bending jump unit preferably has a functional intermediate piece between its ends, in particular with at least one curved leg and/or a folding leg. The functional intermediate piece of the leaf spring is at least partially arranged in a functional section of the housing that preferably faces the opening of the housing. This functional section forms a free space that is preferably as small as possible and is required to switch between the two stable states of the leaf spring. In a housing with a rear and a front housing part, the functional intermediate piece of the leaf spring is in particular arranged at least partially in such a functional section of the rear or front housing part, which preferably faces the opening and the gap.

In a preferred embodiment, the housing of the bending jump unit, in particular the rear and front housing parts, has a projection in order to fix the bending jump unit arranged between the insole and the shoe sole. Furthermore, as explained above, the shoe sole can have a recess for the bending jump unit, so that the bending jump unit can be let into the recess, which also results in fixation.

The bending jump unit arranged between the insole and the shoe sole can be attached to the insole and/or to the shoe sole, preferably by gluing, screwing and/or riveting, in particular by attaching the housing and/or a plate-like end of the leaf spring to the insole and/or attached to the sole of the shoe.

In a housing with a rear and a front housing part, the rear housing part and/or a plate-like end of the leaf spring received therein can be attached to the insole heel part and/or the sole heel part, preferably by gluing, screwing and/or riveting. Furthermore, the front housing part and/or a plate-like end of the leaf spring received therein can be attached to the insole front part and/or the sole front part, again preferably by gluing, screwing and/or riveting.

It can be provided that the rear housing part and/or a plate-like end of the leaf spring received therein is fastened to the insole heel part at its outermost end facing away from the opening and preferably the gap, preferably by rivets or screws, in particular only fastened there. Furthermore, it can be provided that the front housing part and / or a plate-like end of the leaf spring received therein is fastened to the insole front part by rivets or screws at its outermost end facing away from the opening and preferably the gap, in particular only fastened there .

The leaf spring of the bending jump unit can have openings through its plate-like ends in order to fasten the leaf spring by rivets or screws, with one such opening preferably being provided through the outermost ends of the two plate-like ends.

Furthermore, the leaf spring of the bending jump unit can have openings, in particular in its plate-like ends, in order to vary the bending moment and / or the restoring moment for the leaf spring to jump around, in particular to increase this, preferably at least two openings in each case through areas of the plate-like ends facing the functional intermediate piece are provided.

The invention further relates to a bistable bending jump unit which can assume a stable first state and a stable second state and can be suddenly transferred from the first state to the second state by a bending moment and can be suddenly transferred from the second state back into the first state by a restoring moment opposite to the bending moment, especially for a shoe described above.

The bistable bending jump unit comprises a bistable leaf spring that can switch between two stable states and a housing that at least partially surrounds the leaf spring and that has a first triggering means on a first side of the leaf spring and a second triggering means on a second side of the leaf spring.

The first triggering means is arranged on the housing such that when a bending moment acts on the bending jump unit, the first triggering means presses on the first side of the leaf spring such that the leaf spring jumps over, so that the bending jump unit changes from its first state to its second state.

The second triggering means is arranged on the housing in such a way that when a restoring moment opposite to the bending moment acts on the bending jump unit, the second triggering means presses on the second side of the leaf spring in such a way that the leaf spring jumps over, so that the bending jump unit moves from its second state to its second state Initial state returns.

The bistable bending jump unit is designed in particular for arrangement between a shoe sole and an insole of a shoe, in particular a shoe as described above. Accordingly, the bistable bending jump unit is designed in particular as a separate component and in particular does not include the shoe sole and/or the insole itself.

The bistable bending jump unit can also have one or more of the features described above in connection with the shoe.

The invention also relates to a housing for a bistable bending jump unit for receiving a bistable leaf spring, in particular as described above in connection with the bistable bending jump unit or the shoe.

The housing includes a first release means arranged on a first side of the housing such that, when the leaf spring is accommodated in the housing, it exerts pressure on a first side of the leaf spring at a bending moment, so that the leaf spring is released from a first stable State switches to a second stable state.

Furthermore, the housing comprises a second triggering means which is arranged on a second side of the housing opposite the first side in such a way that, when the leaf spring is accommodated in the housing, pressure is applied to a second side opposite the first side at a restoring moment that is opposite to the bending moment the leaf spring exerts, so that the leaf spring switches from the second stable state back to the first stable state.

The housing for receiving a bistable leaf spring is in particular designed to be arranged between a shoe sole and an insole of a shoe, in particular a shoe as described above. Accordingly, the housing is designed in particular as a separate component and in particular does not include the shoe sole and/or the insole itself.

The housing may further have one or more of the features described above in connection with the bistable bending jump unit or with the shoe.

The invention further relates to a method for producing a shoe, in particular a shoe described above.

A first method step is to provide a shoe upper, an insole and a bistable bending jump unit, in particular a bistable bending jump unit as described above. A second method step is attaching a shoe sole to the shoe upper, the insole and/or the bistable bending jump unit.

In a first variant of the method, a shoe sole is provided. Furthermore, the shoe sole is attached to the shoe upper, the insole and/or the bistable bending jump unit by gluing the shoe sole to the shoe upper, the insole and/or the bistable bending jump unit.

In a second variant of the method, liquid shoe sole material is provided. Furthermore, a cover for closing open areas of the bending jump unit and/or the insole is preferably arranged in order to prevent the entry of liquid shoe sole material. The shoe sole is attached to the shoe upper, the insole, the cover and/or the bistable flexural jump unit by feeding the liquid shoe sole material into a sole shape and to the shoe upper, the insole, the cover and/or the bistable flexural jump unit.

Finally, the invention also relates to a shoe that can be produced or manufactured using the method described above.

The invention is explained in more detail below using exemplary embodiments and with reference to the figures, whereby the same and similar elements are partially provided with the same reference numerals and the features of different exemplary embodiments can be combined with one another.

FIG. 1

zeigt einen Schuh mit Schalensohle als Explosionsdarstellung,

FIG. 2

zeigt einen Schuh mit direktbesohlter Sohle als Explosionsdarstellung,

FIG. 3

zeigt eine bistabile Biegesprungeinheit als Explosionsdarstellung,

FIG. 4

zeigt die Oberseite der bistabilen Biegesprungeinheit im geschlossenen Zustand,

FIG. 5

zeigt eine Schnittdarstellung durch die bistabilen Biegesprungeinheit im geschlossenen Zustand,

FIG. 6

zeigt die Unterseite der bistabilen Biegesprungeinheit im montierten Zustand,

FIG. 7

zeigt die Oberseite der bistabilen Biegesprungeinheit im offenen Zustand,

FIG. 8

zeigt eine Schnittdarstellung durch die bistabilen Biegesprungeinheit im offenen Zustand,

FIG. 9

zeigt eine Blattfeder im geschlossenen Zustand,

FIG. 10

zeigt die Blattfeder im offenen Zustand,

FIG. 11

zeigt eine Schnittdarstellung einer weiteren Ausführungsform einer bistabilen Biegesprungeinheit

Short description of the characters:

FIG. 1

shows a shoe with a shell sole as an exploded view,

FIG. 2

shows a shoe with a direct soled sole as an exploded view,

FIG. 3

shows a bistable bending jump unit as an exploded view,

FIG. 4

shows the top of the bistable bending jump unit in the closed state,

FIG. 5

shows a sectional view through the bistable bending jump unit in the closed state,

FIG. 6

shows the underside of the bistable bending jump unit in the assembled state,

FIG. 7

shows the top of the bistable bending jump unit in the open state,

FIG. 8th

shows a sectional view through the bistable bending jump unit in the open state,

FIG. 9

shows a leaf spring in the closed state,

FIG. 10

shows the leaf spring in the open state,

FIG. 11

shows a sectional view of a further embodiment of a bistable bending jump unit

FIG. 1 shows a shoe with a shoe upper 5, an insole 2, a bistable bending jump unit 4 and a shoe sole 1. In this example, the insole 2 is sewn to the shoe upper 5 by a Strobel seam 53. The shoe upper 5 includes a shaft heel part 51 and a shaft plate or shaft front part 52, which overlap one another and are movable relative to one another. The insole 2 is formed in one piece in this example, but comprises two parts, namely an insole heel part 21 and an insole front part 22, which are movable relative to one another because the insole 2 is designed to be flexible overall and is therefore flexible in particular at the bending point 23. In other words, in this example, the insole 2 is not made of a relatively hard or stiff material and does not need to have a gap. The shoe sole 1 also has two parts, namely the sole heel part 11 and the sole front part 12, which are movable relative to one another, the shoe sole 1 being flexible at least at the bending point 13. In this example, the bending point 13 is designed as a thinned sole area that connects the heel part 11 and the front part 12 with one another.

Between the insole 2 and the shoe sole 1 there is a bistable bending jump unit 4, which is attached to the insole, in this example by means of rivets 40. Since the bending jump unit 4 has a certain thickness, a recess 14 is incorporated into the shoe sole 1, which is both in the Heel area 11 as well as in the front area 12 extends and serves to accommodate the bending jump unit 4.

The shoe sole 1 can be produced as a molded part or in another way and, as shown, can be designed in one piece, but can also be designed in several parts. The example shown is a so-called shell sole which encloses the shaft like a shell and is glued to parts of the shaft 5, the insole 2 and the bending jump unit 4. The sole 1 is thus a prefabricated part which is suitably connected to the other parts of the shoe to produce the shoe.

The finished shoe with the built-in bending jump unit 4 is a shoe with an entry aid. Such a shoe can be worn like a regular shoe, that is, there is practically no difference when walking. However, there is relief when putting it on and taking it off. The shoe can be opened for putting on and taking off by putting the bending jump unit 4 into a stable bending state, as shown in FIG. 7 and 8th you can see. As a result, the insole 2 bends along the bending point 23 and the shoe sole 1 bends along the bending point 13 and the heel and front part 51, 52 of the shoe upper 5 move apart, so that the shoe opening enlarges and the shoe can be put on and taken off .

The bending jump unit 4 installed in the shoe can be put into the stable bending state by bending the shoe sole 1 and/or the insole 2 by a certain angle around the bending points 13, 23. A certain bending moment or torque is exerted around the bending points 13, 23 as an axis. For this purpose, for example, if you want to get out of the shoe, the sole-heel part 11 can be held on the ground by loading it with the other shoe and a tensile force can be exerted on the shoe upper with the foot.

Conversely, a restoring moment opposite to the bending moment can be exerted on the bending points 13, 23 of the shoe sole 1 and/or insole 2 in order to put the bending jump unit 4 into a stable flat state, as shown in FIG. 4 and 5 you can see. This allows the shoe to be closed, and the restoring moment can be generated in particular by stepping into the shoe with your foot.

FIG. 2 shows a direct-soled shoe with an entry aid. Apart from the differences described below compared to the shoe with a cup sole described above, it preferably has the same features and properties as the shoe described above.

One difference in particular is the manufacturing process using direct soling. The gluing step can be skipped and the sole can be manufactured directly be injected under the shaft and the insole. The tool costs are typically higher with this process, but the unit costs are generally lower because there is no need to manually glue the sole to the upper.

In order to produce a shoe with an entry aid with a direct sole, it may be advantageous to provide a cover 54 made of an elastic material, as shown in FIG. 2 you can see. This can be used to close open areas. In the case of direct soling, openings in the insole 2 and in the bending jump unit 4 towards the sole 1 are closed with a cover 54 made of elastic material.

If the insole 2 is designed with a gap as a bending point 23, this gap can therefore preferably be closed in order to prevent liquid plastic from flowing through the gap in the insole into the shaft interior during direct soling. An elastic material can be used to compensate for the increase in the gap that occurs when the shoe is opened without blocking the movement.

Furthermore, the bending jump unit 4 or the housing of the bending jump unit 4 can have a gap 45, such as in FIG. 4 you can see. Here too, it can be prevented that plastic flows in through the gap between the front housing part 42 and the rear housing part 41 during direct soling and thereby fills the free spaces 44 which the leaf spring 3 requires in the two stable states. The gap 45 between the housing parts can also be closed using an elastic material, since here too a change in length can occur when the bending jump unit is bent.

Furthermore, the housing parts 41, 42 can be provided with openings or openings, particularly on their underside, which reveal the leaf spring 3 as shown in FIG. 6 you can see. Penetration of the plastic into the free spaces 44 can then also be prevented here by closing these breakthroughs or openings.

The in FIG. 2 The shoe shown has a multi-part, here two-part sole in which the bending point 13 is formed by a gap. However, a one-piece sole can also be formed on the directly soled shoe. Even with what is fortified, especially Gluing a finished sole manufactured shoe can the sole can be one or more parts. With a sole designed in two parts, it is conceivable that the two sole areas in the area of the bending point 13 are connected to one another by means of an elastic material.

The FIG. 3 to 8 show the above-mentioned bistable bending jump unit 4, which can have a rear and a front housing part 41, 42, which are spaced apart from one another by a gap 45 and can be moved in a hinge-like manner relative to one another. The housing parts 41, 42, which can be made of plastic or metal, for example, enclose a typically metallic leaf spring 3, which can assume two stable states and will be described in more detail below. It can also be provided that the housing encloses a spring package consisting of a plurality of leaf springs 3, in particular stacked one above the other.

The housing parts 41, 42 of the bistable bending jump unit 4 are designed in such a way that they form both lower release edges 41B, 42B and upper release edges 41A, 42A. In other words, a housing part forms a trigger edge on its top and bottom sides. These trigger edges each serve to trigger the leaf spring 3 to jump between its two stable states. The housing parts 41, 42 enclose the leaf spring 3, in particular in a form-fitting manner, with the free spaces 44 required by the leaf spring in its two stable states being kept free. The free spaces 44 are kept as small as possible. The housing parts 41, 42 are designed in such a way that the overall height of the bending jump unit 4 remains low in order to enable use in flat soles. The required free spaces 44 are kept as small as possible. When force is introduced, contact quickly occurs between a trigger edge 41A, 41B, 42A, 42B and the leaf spring 3.

The leaf spring 3 then preferably does not react elastically, but remains stiff until the triggering force is reached, which improves the function of the shoe. The housing 41, 42 achieves a high level of rigidity in that the release edges of a housing part 41 and 42 are connected to one another on the two sides. On housing part 41, a force introduced at the trigger edge 41A is also intercepted laterally via the trigger edge 41B. Due to the lateral connection of the top and bottom, the release edges hardly react elastically when force is applied.

As already described above, the insole 2, bending jump unit 4 and shoe sole 1 are preferably glued together, since they transmit the forces that occur when the leaf spring 3 jumps around. In order to improve the force introduction of the bending jump unit 4 towards the sole 1 and the insole 2, the housing parts 41, 42 have a projection 43. The projection 43 can in particular enlarge the adhesive surface with sole 1 and insole 2. When assembled, the projection 43 of the housing parts 41, 42 is located between sole 1 and insole 2.

Due to the particularly identical housing parts 41, 42, which enclose the leaf spring 3 laterally in a form-fitting manner and are also preferably in an adhesive bond with the sole 1 and insole 2 (and preferably in combination with the fixation, for example by rivets 40 on openings 3B), the shaft parts 51, 52 can be prevented. The accommodation of the housing 41, 42 in the recess 14 also counteracts twisting. Such an anti-twist protection is advantageously still guaranteed even if the fastening points (e.g. rivets 40) are reduced, so that in particular, for example, only one fastening point is provided per housing part, which could otherwise result in the loss of the anti-twist protection.

Due to the shoe according to the invention with a bending jump unit 4, which forms upper and lower triggering means (triggering edges), it is in particular not necessary for the insole 2 itself to form triggering edges. This means that the bending jump unit 4 can be used for various common shoe manufacturing processes.

In the case of a lasted shaft 5, for example, a part of the leather, the so-called supplement, is glued or nailed to the underside against the insole 2. A stable insole 2 is typically used in this process. However, lasted shafts are relatively expensive because of the leather surcharge and time-consuming gluing.

The so-called strobing is a cheaper shaft production process. Here, the shaft 5 is sewn to the insole 2. As already explained above, this is done using the Strobel seam 53. There are special sewing machines (Strobel machines) that have this Be able to sew an "angle connection". In this process, the insole 2 is ideally not made of a solid and stiff material, but rather textile. The bending jump unit 4 can also be connected to such an insole 2 of a strobed shaft in order to obtain a shoe with an entry aid.

Like in the FIG. 3 to 8 As can be seen, the leaf spring 3 has openings 3B in order to attach the leaf spring 3 to the insole 2. The housing or the two housing parts 41, 42 also have holes or openings in order to fasten the housing 41, 42 to the insole 42. When the leaf spring is received in the housing, the openings 3B in the leaf spring 3 coincide with the holes or openings in the housing. It is therefore possible, when attaching the leaf spring 3 or the housing 41, 42 to the insole 2, to simultaneously attach the leaf spring 3 relative to the housing 41, 42. However, it can also be provided that the housing 41, 42 is attached, for example glued, to the insole 2 and the leaf spring 3 is in turn attached to the housing, so that the leaf spring 3 is indirectly attached to the insole.

Referring to FIG. 11 For example, the housing can have holding elements 48H arranged in particular in the socket section 48, which engage in the openings in the leaf spring 3. The holding elements 48H can be formed integrally with the housing, that is to say, in the case of a housing made of plastic, they can be designed, for example, as plastic clips which engage in the outer opening 3B of the leaf spring 3 and fix it to the housing.

The bending jump unit 4 or the housing 41, 42 of the bending jump unit 4 can be fastened to the insole 2, for example, using rivets 40 or screws as fastening elements. Preferably, at least one fastening element is provided per housing part 41, 42 or per end of the leaf spring 3, so that there are two fastening points per shoe, which can be sufficient due to the anti-twist protection described above.

In practice it has been found that an attachment with only two attachment points per shoe can be advantageous, especially if the attachment points are arranged at the outermost ends of the leaf spring. Under certain circumstances, the leaf spring 3 can be fixed with more than two fastening elements and/or in places that depend on the the outermost ends of the leaf spring 3 are away, for example closer to the functional intermediate piece of the leaf spring 3, lead to problems such as the breakage of rivets, which is due to shear loads due to the bends that occur when walking within the riveted composite of leaf spring 3, housing 41, 42 and insole 2 can be attributed.

It can therefore be provided that the housing parts 41, 42 are fastened with (exactly) one fastening element (e.g. rivet) per insole part 21, 22. Through this linear arrangement in the longitudinal direction of the shoe, shear loads can be avoided and durability can be increased. In particular, the fastening points (e.g. rivets) are located at the outer ends of the plate-like ends of the leaf spring 30. There are openings for fastening 3B here. This allows the leaf spring to move freely, in particular the plate-like ends 30 can move more freely, and the release force can be increased.

The fastening elements, in particular the rivets 40, can have a diameter that is larger than 3mm, in particular larger than 4mm. For example, diameters between 4mm and 12mm can be provided, preferably between 4mm and 8mm. A diameter of 4.8mm can be particularly cheap. The fastening elements, in particular the rivets 40, can be made of metal, for example aluminum, or preferably stainless steel. Stainless steel rivets have the advantage of greater resilience.

The attachment described at the outermost ends of the leaf spring 3, in particular through openings 3B and preferably with only one fastening element per end of the leaf spring, has advantages in terms of function in addition to the advantages already described in terms of durability.

In particular, the release force can be increased by fastening (only) to the outermost ends of the leaf spring, in particular with only one fastening element. The release force is the force that is necessary to move the shoe from the open to the closed state. A high release force can be advantageous because the shoe only closes (or opens) when the wearer consciously builds up pressure.

The increase in the triggering force is due to the fact that the plate-like ends 30 of the leaf spring 3 are in the two stable states (see FIG. 9 and 10 ) may be slightly curved. In other words, the ends 30 of the leaf springs 3 can be slightly deformed in the transverse axis by the application of force by the bow legs 34.

When the bow legs 34 jump around, the deformation at the ends of the leaf springs 3 can change. If this movement is blocked in the plate-like ends 30 of the leaf spring 3, for example by rivets 40 at the positions where the openings 3A are located, a tension can arise within the leaf spring 3, which counteracts the bistable properties and the triggering forces of the shoe are reduced out of. It may therefore be advantageous not to attach the leaf spring to the openings 3A. Nevertheless, these openings 3A can advantageously influence the tensions in the leaf spring and additionally increase the triggering force. It can therefore be provided that at least one opening in the leaf spring, in particular in a plate-like end 30, which influences the stresses and is not used for fastening, is present. For example, four openings 3A on each leaf spring can be located on the plate-like ends 30 of the leaf spring 30 and near the ends of the bow legs 34. They are advantageous for additionally increasing the release force.

The openings 3A, which can be circular, for example, can in particular have a diameter of over 3mm, preferably over 4mm. For example, it can be provided that the diameter is between 3mm and 12mm or preferably between 3mm and 8mm. A diameter of 4.9mm may be suitable. This in turn allows the triggering force to be additionally increased and/or the tensions that counteract the bistable effect of the leaf spring to be reduced.

The triggering force of the bistable bending jump unit 4 is preferably higher than 1kg, particularly preferably higher than 6kg, very particularly preferably higher than 8kg and even more preferably higher than 10kg, namely for example 11kg.

FIG. 9 and 10 show a bistable leaf spring 3 in its two stable states. The leaf spring 3 has plate-like ends 30. The bistable leaf spring 3 has a central folding leg 33 and two outer bow legs 34. The folding leg 33 has five bends 35 in order to shorten the length of the leaf spring 30, whereby the outer legs 34 assume an arc shape upwards or downwards, depending on the switching state of the bistable leaf spring. As a result of this waviness, the leaf spring 3 occupies a certain spatial height. The housing 41, 42 therefore has free spaces 44 in order to keep this height free. As a result of the internal buckling tension in the bow leg 34, it can jump around due to pressure, which is generated in particular by a triggering means. As described above, edges of the housing are provided in particular, which press against an arch leg 34 of the leaf spring 3, so that the leaf spring 3 or the bending jump unit 4 jumps around. Such a triggering or actuating edge is preferably arranged such that it presses on or near the apex of the bow leg.

By installing the bistable leaf spring 3 in the bending jump unit 4 with its bow legs pointing downwards and its folding legs pointing upwards in the flat state, a particularly stable state for the shoe results.

List of reference symbols:

1

Shoe sole

11

Sole heel part

12

Sole front part

13

Bending point of the shoe sole

14

recess

2

Insole

21

Insole heel part

22

Insole front part

23

Bending point of the insole

3

leaf spring

3A

breakthrough

3B

Breakthrough for fastening

30

Plate-like ends of the leaf spring

34

bow shank

35

folding leg

4

Bistable bending jump unit

40

Rivets

41

rear housing part

41A

lower release means on the rear part of the housing

41B

upper release means on the rear part of the housing

42

front housing part

42A

lower release means on the front part of the housing

42B

upper release means on the front part of the housing

43

projection

44

Open spaces

45

Gap between the rear and front parts of the housing

46

All-round wall

46A,B

First, second wall section

46C,D

Side wall sections

47

Opening to accommodate the leaf spring

48

Version section

48H

Holding element

49

Functional section

5

Shoe shaft

51

Shaft heel part

52

Shaft front part

53

Strobel seam

54

cover

Claims (15)

1. Shoe with step-in aid comprising:

   - a shoe upper (5) having an upper heel part (51) and an upper front part (52), which are movable in relation to each other,

   - an insole (2) having a bending point (23) between an insole heel part (21) and an insole front part (22), which are movable in relation to each other,

   - a shoe sole (1) having a bending point (13) between a sole heel part (11) and a sole front part (12), which are movable in relation to each other,

   - a bistable bending spring unit (4) arranged in the area of the bending point (23) of the insole (2) and the bending point (13) of the shoe sole (1) between the insole (2) and the shoe sole (1), said bistable bending spring unit having a bistable leaf spring (3) configured to spring between two stable states and a housing (41, 42) at least partially surrounding the leaf spring, wherein the housing comprises a free space (44) for springing between the two stable states of the leaf spring,

   - wherein a first release means (41B, 42B) is arranged on the housing (41, 42) of the bending spring unit (4) such that it exerts pressure on a first side of the leaf spring (3) in the event of a bending torque acting on the bending spring unit (4) in order to trigger the leaf spring (3) to spring, so that the bending spring unit (4) abruptly changes from a stable first state to a stable second state and moves the shoe into an open state and

   - wherein a second release means (41A, 42A) is arranged on the housing (41, 42) of the bending spring unit (4) such that it exerts pressure on a second side of the leaf spring (3), which is opposite the first side, in the event of a restoring torque acting on the bending spring unit and opposing the bending torque, in order to trigger the leaf spring (3) to spring over, so that the bending spring unit (4) returns abruptly from the stable second state to the stable first state and move the shoe into a closed state.
2. Shoe according to claim 1, wherein the housing (41, 42) of the bending spring unit (4) comprises a rear housing part (41) and a front housing part (42), on which of which a first and a second release means are arranged and wherein the rear housing part (41) and the front housing part (42) are movable relative to each other, in particular by the action of the bending torque or the restoring torque, preferably with a gap (45) that separates the rear housing part (41) from the front housing part (42).
3. Shoe according to any one of claims 1 or 2, wherein the housing (41, 42) of the bending spring unit (4) integrally forms the first release means (41B, 42B) and/or the second release means (41A, 42A), preferably as an edge of the housing (41, 42).
4. Shoe according to any one of claims 1 to 3, wherein the housing (41, 42) of the bending spring unit (4) with a circumferential, preferably integrally formed wall (46) forms an opening (47) for receiving the leaf spring (3), such that the circumferential wall has a first wall portion (46B) on the first side of the leaf spring and has an opposite second wall portion (46A) on the second side of the leaf spring, wherein the first and second wall portion (46B, 46A) have or form the first or second release means (41B, 41A), preferably form this as an inner edge, and wherein the first and second wall portion are connected to each other via side wall portions (46C, 46D).
5. Shoe according to any one of claims 1 to 4, wherein the leaf spring (3) of the bending spring unit (4) has a plate-like end (30), which is held in a socket portion (48) of the housing (41, 42).
6. Shoe according to any one of claims 1 to 5, wherein the leaf spring (3) of the bending spring unit (4) has a functional intermediate piece between its ends, in particular with at least one bow leg (34) and/or a folding leg (35), and the functional intermediate piece of the leaf spring (3) is arranged at least partially in a functional portion (49) of the housing (41, 42), which forms a free space (44) required for springing between the two stable states of the leaf spring (3), wherein in particular the functional intermediate piece of the leaf spring (3) is in each case at least partially arranged in such a functional portion (49) of the rear or front housing part.
7. Shoe according to any one of claims 1 to 6, wherein the housing (41, 42) of the bending spring unit (4) has a protrusion (43) to fix the bending spring unit (4) arranged between the insole (2) and the shoe sole (1).
8. Shoe according to any one of claims 1 to 7, wherein the bending spring unit (4) arranged between the insole (2) and the shoe sole (1) is fastened to the insole (2) and/or to the shoe sole (1), preferably by gluing, screwing and/or riveting, in particular by fastening the housing (41, 42) and/or a plate-like end (30) of the leaf spring to the insole (2) and/or to the shoe sole (1).
9. Shoe according to claim 8 with reference back to claim 2, wherein the rear housing part (41) and/or a plate-like end (30) of the leaf spring received therein is attached to the insole heel part (21) and/or the sole heel part (11), preferably by gluing, screwing and/or riveting, and wherein the front housing part (42) and/or a plate-like end (30) of the leaf spring received therein is fastened to the insole front part (22) and/or the sole front part (12), preferably by gluing, screwing and/or riveting.
10. Shoe according to claim 9 with reference back to claim 2, wherein the rear housing part (41) and/or a plate-like end (30) of the leaf spring received therein is in each case fastened at its outermost end facing away from the opening (47) and the gap (45) to the insole heel part (21), preferably by rivets or screws, in particular is fastened there only, and wherein the front housing part (42) and/or a plate-like end (30) of the leaf spring received therein is in each case fastened at its outermost end facing away from the opening (47) and the gap (45) to the insole front part (22) by rivets or screws, in particular is fastened there only.
11. Bistable bending spring unit (4) which can assume a stable first state and a stable second state and can be abruptly transferred from the first state to the second state by a bending torque and can be abruptly transferred from the second state back to the first state by a restoring torque opposing the bending torque, for arrangement between a shoe sole (1) and an insole (2) of a shoe, in particular for a shoe according to any one of claims 1 to 10, comprising:

    - a bistable leaf spring (3) that can spring between two stable states and

    - a housing (41, 42), which at least partially surrounds the leaf spring with a first release means (41 B, 42B) on a first side of the leaf spring and a second release means (41A, 42A) on a second side of the leaf spring, wherein the housing comprises a free space (44) for springing between the two stable states of the leaf spring (3),

    - wherein a first release means (41B, 42B) is arranged on the housing (41, 42) such that when a bending torque is exerted on the bending spring unit (4), the first release means (41B, 42B) presses on the first side of the leaf spring (3) such that the leaf spring (3) rebounds so that the bending spring unit (4) springs from its first state to its second state, and

    - wherein a second release means (41A, 42A) is arranged on the housing (41, 42) such that when a restoring torque opposing the bending torque is exerted on the bending spring unit (4), the second release means (41A, 42A) presses on the second side of the leaf spring (3) such that the leaf spring (3) rebounds so that the bending spring unit (4) springs from its second state back to its first state.
12. Housing (41, 42) for a bistable bending spring unit (4) for receiving a bistable leaf spring (3) and for arrangement between a shoe sole (1) and an insole (2) of a shoe, in particular according to claim 11, comprising:

    - a free space for springing the leaf spring (3),

    - a first release means (41B, 42B), which is arranged on a first side of the housing (41, 42) such that when the leaf spring (3) is received in the housing (41, 42) it exerts pressure on a first side of the leaf spring (3) when a bending torque is applied such that the leaf spring (3) springs from a first stable state into a second stable state, and

    - a second release means (41A, 42A), which is arranged on a second side of the housing (41, 42) opposite the first side such that when the leaf spring (3) is received in the housing (41, 42) it exerts pressure on a second side of the leaf spring (3) opposite the first side when a restoring torque opposing the bending torque is applied such that the leaf spring (3) springs from a second stable state back into a first stable state.
13. Method for producing a shoe, in particular according to any one of claims 1 to 10, comprising:

    - providing a shoe upper (5), an insole (2) and a bistable bending spring unit (4) according to claim 11,

    - attaching a shoe sole (1) to the shoe upper (5), the insole (2) and/or the bistable bending spring unit (4).
14. Method according to claim 13 comprising:

    - providing the shoe sole (1),

    - attaching the shoe sole (1) by gluing the shoe sole (1) to the shoe upper (5), the insole (2) and/or the bistable bending spring unit (4).
15. Method according to claim 13 comprising:

    - providing fluid material for shaping the shoe sole,

    - preferably arranging a cover (45) for closing open areas of the bending spring unit (4) and/or the insole (2) to prevent entry of fluid material,

    - attaching the shoe sole (1) by feeding the fluid material into a sole mould and onto the shoe upper (5), the insole (2), the cover (45) and/or the bistable bending spring unit (4).

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