TECHNICAL FIELD

The present disclosure relates to a footwear product as set forth in claim 1. It further relates to a footwear system and a method as set forth in the further independent claims.

BACKGROUND OF THE DISCLOSURE

Footwear products with high heels are fairly common in fashionable ladieswear. They inhere, however, some danger of twisting the ankle, and related injuries. On the upside, high heels mostly exhibit a very slender shape and are attached to an upper part of the footwear product at a very small attachment area. Thus, they break easily, and at a comparatively low tilt angle, which limits the moment acting on the wearer’s ankle, and accordingly the risk of serious injury. Also, the wearer’s forefoot is in contact with the ground, which enables the wearer to react and control the motion, at least to a certain extent. Platform soles may be used for reasons of aesthetics or other effects. A platform height of these platform soles is typically larger than several centimeters and may reach up to several ten centimeters. In this case, the wearer’s entire foot is disconnected from the ground by a fairly large distance. In fact, the effect is comparable to stilt walking with the foot being rigidly attached to the stilt. Twisting the ankle or stumbling may thus easily result in a large moment acting on the ankle, with the resulting danger of severe ankle injuries, or falling down, or both. Moreover, the knee, or soft tissue stabilizing the knee, may be in danger of injury, for instance due to lateral bending.

Numerous embodiments are known in the art which disclose footwear products in which a sole or heel member may be separated from a top member of the footwear product. EP 1 864585 for an instance discloses a footwear construction in which a heel is secured relative to the underside of a sole member by means of a snap fit connection. The snap fit connection is provided to securely and firmly lock the heel to the sole member. The embodiments disclosed in FR 2655521 ,

EP 2474245, DE 102008017674, FR 2980079 and CN 105639848 exhibit interchangeable heels, wherein the interchangeable heels are fixed to a sole or other part of the footwear product by magnets. In said art, the respective connection interfaces comprise bosses or studs such as to secure the heel members of said embodiments against lateral displacement and disconnection due to momenta being effective at the connection interface. US 2007/0000152, US 2,065,325, US 2,009,876 and US 2,478,810 disclose embodiments wherein outsoles or heel lifts are attached to footwear products by means of snap fit connections. In each of the named examples the attached outsole is rather flat and requires manual operation to detach the respective outsole or heel lift member from the footwear product. In an embodiment disclosed in US 2013/0247413 and FR 2980672, heel members are interchangeable, wherein they are connected to an upper part of the footwear product by threads, a system with locking knobs, or rigid snap fit connections. In an embodiment known from US 8,132,341 a heel is attached to another part of the footwear product by a bayonet locking mechanism. In JP 2005046171 it is disclosed that an auxiliary bottom member is removably attached to a standard slipper so as to raise the size of the person wearing the shoe. This document teaches to provide the auxiliary bottom member with a width sufficient to stably support the slipper and provide stability when walking on the slipper with the bottom member attached. DE 297 15533 teaches a footwear product with replaceable soles.

Summarizing, all of the cited embodiments known from the art are intended to securely lock a sole or heel member to a footwear product such that it does not separate from the footwear product during use. In this respect, none of the cited embodiments is suited to provide a footwear product which enables a wearer to separate a heel or sole from the footwear product while walking in the footwear product.

OUTLINE OF THE SUBJECT MATTER OF THE PRESENT DISCLOSURE It is an object of the present disclosure to provide a footwear product of the type initially mentioned. In an aspect, a footwear product shall be provided in which the danger of ankle injuries or falling down while walking in a footwear product with high heels and/or platform soles is reduced when compared to the art. In a more specific aspect, it is an object of the present disclosure to provide a footwear product in which the wearer is enabled to separate a sole member or heel member from the part of the footwear product in which the wearer’s foot is received while he or she walks in the footwear product, and without manual manipulation. It shall be provided that the base member detaches from top member when there is a danger for the wearer for injuries, but stays firmly attached to the top member in non-critical conditions. This is achieved by the subject matter set forth in claim 1.

Further effects and advantages of the disclosed subject matter, whether explicitly mentioned or not, will become apparent in view of the disclosure provided below.

Accordingly, disclosed is a footwear product, wherein the footwear product comprises a top member and a base member. The footwear product may in particular be a shoe. Each of the base member and the top member may be provided in one single part or may in turn be assembled from sub-members. The top member is adapted to receive a foot. The top member comprises a front section and a heel section, wherein in certain embodiments the front section may comprise and extend from a toecap. The top member exhibits a bottom side and an upper side, wherein the top member is closed at the bottom side and is open at the upper side at least in the heel section so as to receive a foot through the opening at which it is open at the upper side in the heel section. The top member may for one non-limiting instance comprise a closed compartment with an opening at the upper side in the heel section to receive a foot therethrough. For another non-limiting instance, the top member may comprise one or more straps spanning the upper side to receive a foot between the straps and a closed bottom. It is understood that the named instances are given as examples only, and other embodiments of top members of a footwear product are possible within the scope of the present disclosure, although not being explicitly mentioned. The base member comprises a bottom side and an upper side, and a platform height between the bottom side and the upper side of the base member. The bottom side of the base member is adapted to contact a ground. In particular instances, an outsole is provided on the bottom side of the base member. For certain instances, also the bottom side of the top member may include an outsole configured and adapted to contact the ground. Thus, the top member may be used as a conventional shoe. The bottom of the top member may for one instance be provided with a rubber sole. The footwear product as herein disclosed is adapted and configured to be functionally assembled from at least the top member and the base member, wherein the upper side of the base member is oriented towards the bottom side of the top member. It is understood that, in instances where the base member is directly attached to the top member, the upper side of the base member faces the bottom side of the top member. Such, the top member may be supported by the base member which is provided below the top member when a wearer walks in the functionally assembled footwear product. A connection interface is provided between the base member and the top member. Connection means are provided at the connection interface so as to connect the two members adjacent the connection interface. The connection means are in particular provided on or within surfaces of the members adjacent the connection interface which border the connection interface. The connection between the top member and the base member may be direct, such that the bottom side of the top member is provided adjacent the upper side of the base member. In said instance, the two members adjacent the connection interface are the top member and the base member. In other instances the connection may be indirect, with one or more intermediate members provided between the top member and the base member when the footwear product is functionally assembled. As noted above, in non limiting embodiments, a surface adjacent the connection interface and on the top side of the connection interface may be adapted and configured to contact a ground, for instance in that an outsole is provided. It may thus be provided that the upper part of the footwear product which is provided on top of the connection interface when the footwear product is functionally assembled, or, in more particular instances, the top member, may be used as a standalone shoe without the bottom member attached, but may also be extended to an elevated height shoe in attaching the bottom member. The connection interface with the connection means are adapted and configured such that the connection interface is reversibly separable and further adapted and configured to be reversibly and non-destructively separated by a moment applied, or effective, at the connection interface when said moment is above a threshold moment. On the other hand, the connection interface with the connection means are adapted and configured such that the top member and bottom member stay fixed to each other when said moment is below the threshold moment. The threshold moment is larger than or equal to 0.5 Nm and smaller than or equal to 30 Nm, in particular larger than or equal to 1 Nm and smaller than or equal to 25 Nm, more in particular larger than or equal to 1.5 Nm and smaller than or equal to 20 Nm, more in particular larger than or equal to 2 Nm and smaller than or equal to 15 Nm, more in particular larger than or equal to 2.5 Nm and smaller than or equal to 10 Nm and more in particular larger than or equal to 3 Nm and smaller than or equal to 6 Nm. “Reversibly separable” will be readily understood as the separation being non destructive such that, after separation, no repair is needed, and a footwear product with a separated base member may immediately be re-assembled if desired.

A laterally acting force applied for instance at the bottom side of the base member, or at the ground contact location of the footwear product, yields, through the lever provided by the height of the base member, a moment at the connection interface. It will be appreciated that such a laterally acting force at the bottom of the base member may result from the gravitational force when the person wearing the footwear is about to start an ankle twisting motion.

In an exemplary instance, the connection interface is adapted and configured such that the connection interface is separable by a bending moment, in particular around a toe-heel axis of the footwear product, or in other words, in a frontal plane of the footwear product. The wearer may exert this moment in particular in two ways. She or he may either support the base member on the ground and perform an eversion or inversion of the foot, that is, turn the foot around its longitudinal, toe-heel, axis. This motion takes place when a wearer is in danger of twisting the ankle. Thus, a bending moment around said toe-heel axis becomes effective at the connection interface. The wearer may furthermore support the base member laterally against a firm object, like for instance a step, and perform an adduction or abduction of the leg towards the firm object. Thus, a lateral force is exerted at the top member of the footwear product, a counteracting lateral force is exerted at the bottom of the base member, and a resulting bending moment around the toe-heel axis becomes effective at the connection interface to separate the base member from the top member.

It is understood that the separation should be effected if the moment effective at the connection interface exceeds the threshold value, while the base member remains securely fixed to the top member during normal use of the footwear product. The threshold value should be chosen such that a separation of the base member from the top member occurs if a moment becomes effective at the connection interface which is sufficiently low in order not to cause any or at least not any serious harm or injury to the wearer’s ankle or knee. Suitable ranges for the threshold moment are provided above.

It is appreciated that in the current context spatial designations like top, base, bottom, upper, lower, front, back, lateral, and the like are related to the position of the footwear product for intended use. Also, toe and heel indicate well-defined directions or positions in connection with a footwear product, that is, when a wearer stands on the ground wearing the footwear product. In this respect, the skilled person will readily appreciate that designations of directions and relative positions have clear and unique meanings in the context of a footwear product as such and are independent from the actual orientation of a member in space.

It is further noted that within the framework of the present disclosure the use of the indefinite article “a” or “an” does in no way stipulate a singularity nor does it exclude the presence of a multitude of the named member or feature. It is thus to be read in the sense of “at least one” or “one or a multitude of”.

It is moreover noted that in the context of the present application the terms “bordering” and “adjacent” as well as “bordering” and “adjacent to” are considered as synonyms. It is noted that a functionally assembled footwear product of the kind herein described may comprise one or more base members. For instance, one base member may be provided which may more specifically extend from a toe region to a heel region, and may be provided with a constant or a variable platform height, which may in particular increase from a front or toeside end to a back or the heelside end. In another instance, a first base member may be provided in the front or toe region of the footwear product and a second base member may be provided in the back or heel region of the footwear product. More base members may be provided, with equal or different platform heights, which may in certain embodiments increase from the front to the back. A minimum platform height of a base member may in embodiments measure 5 cm or more, more in particular 7 cm or more, and even more in particular 10 cm or more.

It will be appreciated that the desirable threshold moment may depend upon the wearer’s physical conditions, such as, while not limited to, size, weight or the conditions of the muscles and ligaments supporting the ankle and/or knee and/or hip. It will be appreciated that, for instance, for a comparatively heavier wearer it may be desirable if the threshold moment is higher than for a comparatively lightweight wearer. It may thus be provided that the threshold moment is adjustable.

In certain aspects, the connection means may be adapted and configured to be non-destructively separable by a pulling force normal to a surface of the connection interface.

Further, in certain embodiments of the footwear product according to the present disclosure, the connection means are provided on the surfaces bordering the connection interface. Thus, the connection means are not visible from outside when the footwear product is functionally assembled, which may yield advantages with respect to aesthetics of the footwear product. Below, some exemplary embodiments of suitable connection means are mentioned for reference. However, it is understood that these examples are in no way intended to be comprehensive and/or to limit the scope of the present disclosure and/or the protection for which is sought.

For one instance, the connection means may comprise at least a pair of magnetically attracting fasteners provided on the members adjacent the connection interface. The number and/or strength of the magnetically attracting fasteners may be varied so as to provide for an adjustable threshold moment. For a further instance, the connection system may comprise at least a pair of hook- and-loop fasteners provided on the members adjacent the connection interface. Hook-and-loop fasteners in this respect should be broadly understood as any pair of members providing fastening surfaces which are populated by structures which provide a mutual form locking interlock effect due to elastic deformation and elastic restoring forces and resulting interlocking undercuts upon mating the fastening surfaces. In certain embodiments the height of the interlocking structures is in a range of less than 5 mm, in more specific embodiments less than 3 mm, and in even more specific embodiments 1 mm or less. In this respect, a pair of hook-and- loop fasteners as herein referenced may comprise, while not being limited to, fasteners with hooks provided on one fastening surface and loops on the counterpart surface, hook and pile fasteners, touch fasteners, or mushroom head lock fasteners. At least some of the hook-and-loop fasteners may me removable and/or interchangeable. Thus, the interlocking surface and/or interlocking strength per unit area of hook-and-loop fasteners may be varied so as to provide for an adjustable threshold moment. For a further instance, the connection means may comprise at least one adhesive fastener provided on at least one of the members adjacent the connection interface. At least some of the adhesive fasteners may be removable and/or interchangeable. Thus, the adhesive surface and/or adhesive strength per unit area of adhesive fasteners may be varied so as to provide for an adjustable threshold moment. For still a further instance, the connection means may comprise at least one pair of mutually interlocking elements provided on the members adjacent the connection interface. It is understood that, in particular, out of each pair of mutually interlocking elements at least one should be resiliently elastic such as to allow mutual interlocking and an interlock due to resilient deformation and rebound upon mating a pair of mutually interlocking elements.

The at least one pair of mutually interlocking elements may in more specific embodiments comprise at least one pair of positive form lock elements, wherein the interlocking flanks of mutually interlocking positive from lock elements are provided as smooth ramps in and against the interlocking direction such that they may be engaged through a pushing force and disengaged by a pulling force without destroying the form lock elements. That is to say, in other words, any undercuts provided to achieve the positive form lock interlocking effect are shaped such that they are not self-retaining against disengagement; however, interlocking is maintained through the positive form lock until a certain disengagement pulling force is applied to the pair of positive form lock elements. In particular, the at least one pair of interlocking elements may comprise a snap fit joint. At least one pair of mutually interlocking elements may be a press button.

The mutually interlocking elements provided on the base member and the adjacent member may be replaceable so as to provide pairs of mutually interlocking elements with different interlocking strength, and/or the interlocking elements may be configured to provide a variable interlocking force with its counterpart interlocking element so as to provide an adjustable interlocking strength and hence allow an adjustment of the threshold moment. For instance, resiliently elastic members may be provided with biasing means for effecting an adjustable bias.

It is understood that the connection means may comprise more than one pair of interlocking elements, and it is further understood that at least one pair of mutually interlocking elements may be combined with other attachment means, such as, while not limited to, one or more pairs of magnetically attracting fasteners, hook- and-loop fasteners, and/or adhesive fasteners.

As implied above, the connection interface may be provided between the bottom side of the top member and the upper side of the base member such that the base member may be directly attached to and located adjacent the top member when the footwear product is functionally assembled

In a further aspect, the members adjacent and bordering the connection interface comprise at least two pairs of mutually matching registering elements so as to define the relative position of the adjacent members with respect to each other and guarantee a well-defined mutual position of the base member and the top member. It is understood that the pairs of registering elements are in particular provided on the upper surface of the lower adjacent member and the lower surface of the upper adjacent member, wherein said upper and lower surfaces face each other and border the connection interface when the footwear product is functionally assembled. In particular embodiments, a female or concave registering element is provided in the upper one of the two adjacent members and a matching counterpart male or convex registering element is provided in the lower one of the two adjacent members. That means, the lower surface of the upper member may be free from protruding elements and thus may be suitable as an outsole, such that an upper part of the footwear product is suitable for walking when the lower member or a lower part is removed.

The mutually fitting registering elements may comprise a pair of female or concave and counterpart male or convex cones. Those yield, as will be appreciated, the advantage of being self-centering when joined with each other. There may a pair of mutually matching registering elements be provided in the heel region of the footwear product, while a further pair of mutually matching registering elements may be provided in the toe or ball region. Thus, the mutual position of the base member and the top member when assembled with each other is well-defined. At least one registering element out of a pair of mutually matching registering elements may exhibit recesses and/or slots so as to be able to accommodate for deformations in the interface region when walking and thus to maintain the registering when walking with the footwear product.

In further embodiments, the registering elements may be provided on a support member which is provided at the bottom of the member adjacent the connection interface on the top side of the connection interface, for more specific instances on the bottom of the top member. Moreover, the connection means may be attached to the support member. More specifically, the support member may be countersunk in a bottom surface of the member adjacent the connection interface of the top side of the connection interface, or the top member, such that no element protrudes from the bottom surface. Thus, a plain bottom surface is provided, suitable for walking thereon, i.e. suitable for use as an outsole. The support member may in particular be made from a harder material, having a higher modulus of elasticity, when compared to the bottom surface of the member adjacent the connection interface on the top of the connection interface. The modulus of elasticity of the support member may more in particular be at least twice the modulus of elasticity of the bottom surface of the member adjacent the connection interface on top of the connection interface, and more in particular may be more than five times or more than ten times the modulus of elasticity of the bottom surface of the member adjacent the connection interface on top of the connection interface. Hence, the support member may be provided sufficiently rigid and stiff so as to maintain the registry of the registering elements when walking in the functionally assembled footwear product, while the bottom of the member adjacent the connection interface on the top of the connection interface may be sufficiently soft to be suitable as an outsole. The support member may thus also be referred to as a rigid support member. As implied above, in non-limiting embodiments, the upper side of the base member extends at least essentially from a front end of the bottom side of an upper adjacent member to a back end of the bottom side of an upper adjacent member when the footwear product is functionally assembled. More specifically the upper side of the base member may at least essentially cover the entire bottom side of an upper adjacent member arranged adjacent the upper side of the base member when the footwear product is functionally assembled. In particular, the adjacent surfaces bordering the connection interface may be congruent.

In a further aspect, a footwear system is disclosed wherein several base members are provided and may be interchanged and replace each other so as to provide a footwear product with a variable aesthetic appearance and/or platform height.

In still a further aspect, a footwear system is disclosed wherein the system comprises a footwear product of any type outlined above and further comprises a multitude of interchangeable connection means so as to allow for an adjustment of the threshold moment.

Further disclosed is a method of separating the base member from the top member of a footwear product of the type outlined above. The method comprises introducing and engaging a foot in the top member of the footwear product, stepping on a ground with the base member, and applying a normal force onto the ground between the base member and the ground. In a first aspect, the method comprises performing a rotation of the foot at least essentially around an axis of the lower leg, that is, performing an adduction or abduction of the foot relative to the leg. In another aspect, the method comprises performing a rotation of the foot at least essentially around a longitudinal axis of the foot, that is performing an eversion or inversion of the foot. In still a further aspect, the method comprises moving the foot laterally, that is performing an adduction or abduction of the leg, such as to exert a lateral force on the top member and a counteracting lateral force at the bottom side of the base member. It is understood that the features and embodiments disclosed above may be combined with each other. It will further be appreciated that further embodiments are conceivable within the scope of the present disclosure and the claimed subject matter which are obvious and apparent to the skilled person.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter of the present disclosure is now to be explained in more detail by means of selected exemplary embodiments shown in the accompanying drawings. The figures show Fig. 1 a side view of an exemplary embodiment of a footwear product as herein described; Fig. 2 a section of a footwear product in a frontal plane outlining a first exemplary embodiment of connection means for attachment of a base member to a top member; Fig. 3 a section of a footwear product in a frontal plane outlining a second exemplary embodiment of connection means for attachment of a base member to a top member;

Fig. 4 a section of a footwear product in a frontal plane outlining a third exemplary embodiment of connection means for attachment of a base member to a top member;

Fig. 5 a section of a footwear product in a sagittal plane outlining an exemplary arrangement of connection means along the toe-to-heel direction of a footwear product according to the present disclosure;

Fig. 6 a view onto the top of an exemplary embodiment of a base member outlining an exemplary arrangement of connection means and registering elements; Fig. 7 a view onto the bottom of an exemplary embodiment of a top member outlining the arrangement of connection means and registering elements complementary to the embodiment of the base member of fig. 6; Fig. 8 an exemplary embodiment of a support member on which registering elements are provided and which is adapted and configured for attaching connection means thereto;

Fig. 9 an additional optional feature of the herein described footware product in a first view; and Fig. 10 the optional feature of fig. 9 in a second view.

It is understood that the drawings are highly schematic, and details not required for instruction purposes may have been omitted for the ease of understanding and depiction. It is further understood that the drawings show only selected, illustrative embodiments, and embodiments not shown may still be well within the scope of the herein disclosed and/or claimed subject matter. EXEMPLARY MODES OF CARRYING OUT THE TEACHING OF THE PRESENT DISCLOSURE

Figure 1 depicts a shoe 1 with a platform sole as an exemplary embodiment of a footwear product of the type herein described. Shoe 1 comprises top member 10 and base member 20. Top member 10 and base member 20 are joined at connection interface 30. Shoe or footwear product 1 is functionally assembled from the top member and the base member. The shoe is intended to be placed on a ground 100 at a bottom side of base member 20. An outsole may be provided at the bottom of base member 20. In this respect, spatial orientations or designations like up, down, bottom, top, upper, lower and so forth are clearly defined with respect to footwear product or shoe 1 when placed on the ground as in intended use. Top member 10 is adapted and configured to receive a foot through an opening 13 which is provided at the upper side of top member 10 in a heel section of the top member. As top member 10 is intended to receive foot, it is clearly defined where a front or toe side 11 of the shoe is located and where a back or heel side 12 of the shoe is located. In this respect, it is appreciated that also front and back have clear and unique meanings in the context of a footwear product. Top member 10 and base member 20 are joined at connection interface 30 with a bottom side of top member 10 and an upper side of base member 20 bordering the connection interface. It is understood that top member 10 is closed at its bottom side, and, as mentioned above, comprises an opening 13 at its upper side and in the heel section, adjacent back or heel side 12, such as to receive a foot therethrough. Apart from opening 13, top member 10 is shown as a closed containment for a foot. However, other embodiments are conceivable in which an upper part of top member 10 is provided with additional openings, or in which straps are provided extending from one lateral side of top member 10 to another lateral side of top member 10 and extending over the upper side of top member 10. Base member 20 exhibits a platform height h measured from the bottom side of base member 20 to the upper side of base member 20. While in the present exemplary embodiment platform height h is shown constant from the front side of the shoe to the back side of the shoe, embodiments are conceivable in which platform height h for example increases from the front end of the shoe to the back end of the shoe. Furthermore, shoe 1 is shown as comprising one single base member 20 which comprises a front section 21 and a heel section 22. The base member extends at least essentially from a front end of the bottom side of the top member to a heel end of the bottom side of the top member such that the upper side of the base member at least essentially covers the entire bottom side of an adjacent member arranged adjacent the upper side of the base member.

However, embodiments are conceivable in which a front section and a heel section of the base member are provided as separate members. It will be appreciated that connection means are provided for attaching the base member to the top member. The connection means are provided between the upper side of the base member 20 and the bottom side of top member 10. Thus, the connection system is not visible in a functionally assembled footwear product.

Figure 2 shows a sectional view of an exemplary footwear product, wherein the section is taken in a frontal plane. That is, in other words, the plane of the drawing is perpendicular to that of figure 1. Base member 20 and top member 10 are shown separated from each other. A containment 19 of top member 10 is visible in which a foot may be received through opening 13 at the upper side of top member 10. As mentioned above, top member 10 is closed at its bottom side 14. Base member 20 comprises upper side 23 and bottom side 24, wherein, as mentioned above, bottom side 24 is intended to be in contact with the ground when the footwear product is in use and may be provided with or as an outsole. The surface of bottom side 14 of the top member 10 and the surface of upper side 23 of base member 20 each comprise a recess. The recesses in the top and bottom members are intended to receive connection means and are provided so as to at least overlap, or, in embodiments, be coincident with a counterpart recess in the other one of the top and bottom member when the footwear product is functionally assembled. In the embodiment shown in figure 2, a ferromagnetic plate 34 is arranged inside the recess on the bottom side 14 of top member 10. Magnets 31 are attached to the base member 20 and in the recess of the top side 23 of base member 20. Hence, a pair of magnetic mutually attracting fasteners - namely magnets and ferromagnetic plates - is provided on the members adjacent the connection interface. In the embodiment shown, the magnets are releasably attached to the base member, for instance by screws as indicated at 38. Thus, the number of magnets may be varied and magnets of different strength and/or surface area facing the ferromagnetic plate may be used, and thus the magnetic coupling force between the magnets of the base member and the ferromagnetic plate of the top member, and consequently the threshold moment, may be varied. Likewise, the ferromagnetic plate may be interchangeable so as to vary for instance the surface area of the ferromagnetic plate facing the magnets. It will be appreciated that also a further magnet may be installed at the top member instead of the ferromagnetic plate. The skilled person will appreciate that for the magnetic coupling the plate 34 and the magnets 31 will not need to be in contact with each other, such, that it is possible to maintain a distance between the ferromagnetic plate 34 and the magnets 31 when the footwear product is functionally assembled, and have to surfaces of the bottom side 14 of top member 10 and the upper side 23 of the base member in well-defined contact with each other. A distance member 32 is applied to define the remaining distance between the magnets 31 and the ferromagnetic plate 34 when the footwear product is functionally assembled. To this extent, in the exemplary embodiment of figure 2, the ferromagnetic plate 34 is countersunk inside the recess in the surface of the bottom side 14 of the top member by a depth d, while a top surface of the magnets 31 protrudes from the surface of the upper side 23 of the base member by a height s. The magnets 31 and distance member 32 are chosen such that height s is maintained smaller than depth d, thus maintaining a distance (d-s) between the magnets and the ferromagnetic plate when the footwear project is functionally assembled. It will be appreciated that also this distance has an effect on the coupling force and hence the threshold moment. Thus, for a given set of magnets the threshold moment may also be varied in applying distance members 32 of different thickness. It is noted that, in the shown exemplary embodiment, the magnets are shown to be attached to the base member by screws. The skilled person will appreciate that any other suitable attachment method and device for, in particular releasably, attaching the magnets to the base member may be applied. The ferromagnetic plate may be fixedly attached to the top member, but may in embodiments also be releasably attached to the top member, for instance by screwing, while any other suitable method of attaching the ferromagnetic plate to the top member may be applied.

In this respect, a footwear system is disclosed which comprises one or a multitude of top members, one or a multitude of base members, one or a multitude of ferromagnetic plates and/or magnets connected or connectable to a top member at the bottom side thereof, and at least one of a multitude of magnets and of a multitude of distance members connectable to a base member on the top side thereof.

The embodiment shown in figure 3 is very similar to the one shown in figure 2, whereas, instead of a pair of magnetic mutually attracting fasteners a pair of hook- and-loop fasteners 35, 36 are provided as connection means. The hook-and-loop fasteners are attached to the top member 10 and the base member 20, respectively, by means of screws 38 and 39. Hence, the hook-and-loop fasteners may be exchanged with hook-and-loop fasteners having a different interlocking strength, thus enabling variation and adjustment of the threshold moment. Further, at least one adhesive fastener may be provided instead of the magnetic mutually attracting fasteners or the hook-and-loop fasteners. Also, an adhesive faster may be releasably attached to the base member and/or the top member so as to apply adhesive fasteners of different adhesive strength and vary and/or adjust the threshold moment. Again, it is understood that the hook-and-loop fasteners and adhesive fasteners may be attached to the base member and/or top member by screwing or any other suitable attachment means and/or method.

Further, a footwear system is disclosed which comprises one or a multitude of top members, one or a multitude of base members, and a multitude of hook-and-loop fasteners connectable to connectable to at least one of a top member at the bottom side thereof and a base member on the top side thereof. In still a further aspect, a footwear system may comprise one or a multitude of top members, one or a multitude of base members, and a multitude of adhesive fasteners connectable to at least one of a top member at the bottom side thereof and a base member on the top side thereof. The skilled person will further readily appreciate that different types of connection means may be combined within one footwear product and/or provided in one footwear system.

Figure 4 shows a further exemplary embodiment of a footwear product of the type herein disclosed. The connection system in this case comprises two mutually interlocking pairs of elastic tongues 42, 43 provided on the bottom side 14 of top member 10, and 44, 45 provided on the upper side 23 of base member 20. Elastic tongues 42, 43, 44 and 45 are dimensioned, shaped and arranged such that tongues 44 and 45 may be received between tongues 42 and 43 upon an elastic outward deformation of tongues 42 and 43 and/or an elastic inward deformation of tongues 44 and 45. The pairs of tongues thus jointly form a pair of interlocking elements. It is noted that, while in some embodiments all tongues 42, 43, 44 and 45 may be provided as elastic tongues, it is sufficient if out of each pair of mutually interlocking tongues 42, 44 and 43, 45, respectively, one tongue is provided with a sufficient elasticity or resilience such that the tongues may mate by displacement of the tip of at least one tongue and may provide a form lock due to elastic rebound. When the footwear product is functionally assembled, tongues 44 and 45 are interlocked with tongues 42 and 43 through respective undercuts. As is seen, the interlocking flanks of the tongues, that is the laterally inner flanks of tongues 42 and 43 and the laterally outer flanks of tongues 44 and 45, are smoothly shaped and form smooth ramps in and against the interlocking direction. Such, they may be engaged through a pushing force while displacing the upper side 23 of base member 20 towards the bottom side 14 of top member 10, and may be disengaged by a pulling force when separating base member 20 from top member 10. It is noted that the pairs of tongues are positive form lock elements and may be disengaged without destroying the tongues. The skilled person will further appreciate that due to an elastic interlocking force, wherein the pairs of tongues are interlocked by mutually engaging undercuts, a threshold force needs to be applied in order to disengage the thus provided connection system, while at lower disengagement forces the tongues are safely interlocked and provide a secure attachment of base member 20 to top member 10. A biasing member may be provided so as to apply an adjustable biasing force on at least some of the tongues, wherein the adjustable biasing force serves to adjust the force needed to separate the interlocked tongues from each other, and hence to adjust the threshold moment. In the shown exemplary embodiment, an extendable threaded element 46 is provided between the inner pair of tongues 44, 45. It will be readily appreciated that, if the length of extendable threaded element 46 is increased, the resulting bias on tongues 44, 45 will increase the threshold moment, while shortening the extendable threaded element 46 reduces the bias and hence reduces the threshold moment. In other exemplary embodiments at least one tongue or at least one of the pair of tongues on the top member and pair of tongues on the bottom member may be interchangeable in order to vary the interlocking strength of the mutually interlocking tongues.

Figure 5 depicts a longitudinal or sagittal section of an exemplary embodiment of a footwear product of the type herein described. In this embodiment, two pairs 4a and 4b of interlocking elements are provided spaced from each other in a longitudinal, that is, toe-to-heel, direction in order to provide sufficient stability of the functionally assembled footwear product.

Figure 6 shows a view on the upper side 23 of base member 20 of a specific embodiment of the herein disclosed footwear product. Two magnets 31 are provided at the upper side 23 of base member 20 and attached the base member by means of screws 38. One magnet, as a connection means for connecting the base member to a top member, is provided in the posterior or heel and midfoot region, while a second method is provided in the anterior or ball and toe region. Furthermore, two protruding cones 25 - actually shaped as truncated cones - are provided as convex registering elements, wherein one of the convex registering elements is provided anteriorly and the other one is provided posteriorly. Figure 7 depicts the counterpart arrangement on the bottom 14 of top member 10. Ferromagnetic plates 34 are attached to top member 10 by means of screws 39. Convex registering elements are shaped as convex truncated cones 15 in the surface of the bottom side 14 of the top member and shaped and dimensioned to fittingly receive protruding cones 25 provided on the top side of the base member. The ferromagnetic plates 34 and the convex cones 15 are arranged on the bottom 14 of the top member so as to be in registry with their counterparts on the top side of the base member when the footwear product is functionally assembled, and in particular when the upper side of the base member is in registry with the bottom side of the top member. The relative position of the base member and the top member, or, more generally spoken, the members adjacent the connection interface, is provided by the interlocking registering elements 15 and 25. The convex registering cones 15 are slotted so as provide some elastic deformation capability and hence to accommodate for relative movement and maintain the registry of the registering elements and, accordingly, the top member and the bottom member also upon elastic deformation when walking in the footwear product. The convex registering elements are shaped in a support member 16, and the ferromagnetic plates are attached to the support member, whereas support member 16 is attached to top member 10 by means of screws 17. In other exemplary embodiments, the support member may be glued to the top member or be attached to the top member by any other suitable means or method, or may form a single one-piece member with the top member. The bottom side 14 is shaped such that no element protrudes from the surface of the bottom side 14. Hence, the bottom surface of the top member is suitable for walking on. To this extent, the surface of the bottom side of the top member may be provided as an outsole, and may be shaped from a relatively soft material, such as, for instance, while not being limited to, rubber. Being shaped from a relatively soft material, the bottom of the top member can adapt to a ground and provide sufficient friction with the ground to enable walking on the ground with the top member as a standalone shoe. Support member 16 is made from a harder material, having a higher modulus of elasticity, when compared to the bottom surface of top member 10.

The modulus of elasticity of the support member 16 is at least twice the modulus of elasticity of the bottom surface of top member 10, and more in particular may be more than five times or more than ten times the modulus of elasticity of the bottom surface of top member 10. Such, the support member is sufficiently rigid and stiff so as to maintain the registry of the registering elements when walking in the functionally assembled footwear product, while the bottom of top member 10 is sufficiently soft to be suitable as an outsole. Support member 16 may thus also be referred to as a rigid support member. Support member 16 is countersunk in the bottom surface of member 10 so as not to impede walking on the bottom surface of the top member.

Figure 8 shows an exemplary embodiment of a rigid support member 16 in more detail. Support member 16 comprises concave registering elements or concave cones 15. Each of the concave registering elements 15 comprises, in the depicted exemplary embodiment, four slots 115, only some of which are denoted by reference numerals in the drawing, in the wall thereof and extending at least essentially along the cone longitudinal axis. Said slots provide for some enhanced elastic deformation capability of the concave registering elements so as to accommodate for elastic deformation when applying load upon walking in the footwear product. Thus, convex registering elements 25 (of. figure 6) are securely maintained within concave registering elements 15 even when walking in the footwear product and thus causing elastic deformation of the outsole of the top member and of support means 16. Further, support member 16 comprises through holes 117 which are intended to receive screws 17 (of. figure 7) for attaching support member 16 to top member 10, and threaded holes 139 which are intended to receive screws 39 (of. figure 7) for attaching connection means, for instance ferromagnetic plates 34, shown in figure 7, to the support member. The support member may for non-limiting instances made from metal or from, for other instances, plastics like, while not limited to, polyamide, polypropylene, polyethylene, polyoxymethylene or polycarbonate, wherein these materials may be fiber reinforced, for instance by carbon or glass fibers, or may be non-reinforced.

In particular in instances in which the herein disclosed footwear product is used as a convertible footwear product, that is, as a footwear product with varied platform height, an aesthetically unwanted effect may arise. That is, a bottom surface of a member may in instances be used as an outsole and thus become worn, while, in other instances, the same bottom or lower surface may be arranged adjacent an upper surface of a bottom member of the footwear product. For instance, the top member may be alternatively used as a standalone shoe, as mentioned above, or may be combined with a platform member attached to the bottom or lower side of the top member. In the latter case, the edge of the outsole may at the same time be an edge of the interface between an upper and lower member. Then, the wear of the outsole may be visible on the lateral surface of the footwear platform. This issue may be remedied by the particulars outlined in connection with figures 9 and 10. A bottom side 14 of a lower section 101 of an upper or top member 10, in these particular embodiments, exhibits a plateau 112 encircled by a rim 111 and having sloped flanks 110. Lower member or bottom member 20 exhibits, on its upper or top side 23, a depression 211 encircled by a skirt 210. Depression 211 is sized and shaped to receive plateau 112. The height of skirt 210 is chosen such that, when assembling the upper and lower members, convex registering members 25 engages concave registering members 15, and furthermore magnets 31 and ferromagnetic plates 34 may couple with each other. More generally, as the skilled person will readily understand, this dimensioning will also allow other types of connection members to get into a functional relationship and lock the upper and lower member to each other. This may, in embodiments, be achieved in that the height of skirt 210 is chosen at least marginally smaller than the height of plateau 112. In other embodiments, convex registering members 25 and the connection means provided on the bottom member 20, such as, while not limited to, magnets 34 shown in figure 9, may be provided on elevations at the bottom of depression 211. In the embodiment shown, the flanks 110 of plateau 112 as well as the inner walls of skirt 210 are sloped. The skilled person will appreciate that the geometry of the flanks 110 of plateau 112 and the inner walls of skirt 210 need to be adapted to each other in such a way as to allow disengaging the upper member and the lower member from each other by a tilting movement about an anterior-posterior axis of the footwear product. In the shown embodiment, the slopes 110 of plateau 112 as well as the inner wall of skirt 210 are sloped so as to enable a tilting around the anterior-posterior axis of the footwear product for disengaging the upper member 10 from lower member 20. As will be appreciated, when walking on the bottom side 14 of upper member 10 only the plain bottommost surface of plateau 112 will get into contact with the ground and thus experience wear, while rim 111 will remain proper and clean. When upper member 10 and lower member 20 are assembled, the worn surface is hidden inside depression 211 , while the visible edge of rim 111 is not affected by wear. The skilled person will readily appreciate that the members shown in figures 9 and 10 may by way of example be the top and bottom members, or, more generally, in a footwear product comprising more than just two members, the members illustrated in figures 9 and 10 may be an upper and a lower member adjacent a connection interface. However, as will be appreciated, the circumferential seam between the upper member and the lower member will be visible when the upper and lower members are assembled and may exhibit a gap. In order to camouflage this seam, the upper and lower member may, in an embodiment not shown in the drawings, comprise circumferential furrows and/or rims adjacent their lower and upper sides, 14 and 23, respectively, as optional aesthetic features.

While the subject matter of the disclosure has been explained by means of exemplary embodiments, it is understood that these are in no way intended to limit the scope of the claimed invention. It will be appreciated that the claims cover embodiments not explicitly shown or disclosed herein, and embodiments deviating from those disclosed in the exemplary modes of carrying out the teaching of the present disclosure will still be covered by the claims.