Attorney Ref.: P6386PC00

DESCRI PTION

Title

SHOE SOLE

Technical Field

[0001] The present invention generally relates to a shoe sole to which upper material may be attached in a variable manner and to respective footwear.

Background Art

[0002] Footwear with interchangeable upper materials has been known for some time and allows the person who wears them to change the physical aspect of the shoes by using the same sole unit wherein conventional mounting techniques for a permanent connection of shoe sole and upper material, for example bonding, welding, suturing and the like are avoided.

[0003] A convertible shoe having a sole and releasable upper strap portions is disclosed in US 4,450,633. Anchoring means attached to the sole edge cooperate with ring means at the ends of the strap portions to releasable secure the upper and sole portions.

[0004] However, such type of shoe does not permit the wearer to adjust and adapt the positioning of the replaceable upper material, this being the reason why the use of this type of footwear is somewhat limited.

[0005] From WO 2012/116382 A1 , a shoe is known which comprises a sole made of plastic, leather, cork, wood, or the like, which is provided with through-holes extending perpendicularly to the longitudinal axis of the sole for variably accommodating bands drawn through for fastening the sole to the foot wherein the holes of the sole through which no bands are drawn during use are covered with decorative plugs or decorative screws to prevent foreign bodies from entering these holes. [0006] Since according to this solution the respective bands or straps of the upper material are immovably arranged in respectively tailored through-holes within the sole main body, the mounting options are restricted and the fit may not be optimally adopted to the foot of the wearer.

[0007] It is therefore the object of the present invention to provide an improved shoe sole which on the one hand does not need to be glued, welded, sewed or vulcanized to an upper material and on the other hand provides the wearer with a greater flexibility regarding mounting options for a wide variety of upper materials as well as with improved adjustment characteristics with regard to individual needs of the wearer.

Disclosure of the Invention

[0008] According to the invention these needs are settled by a shoe sole for variably attaching upper materials according to independent claim 1 . The shoe sole comprises a main body having a longitudinal axis, an upper side, a lower side, a right-hand side region, a left-hand side region, a front end region and a rear end region. At the outer circumference of the upper side of the main body there are arranged at least six ribshaped protrusions at the right-hand side region, at the left-hand side region, at the front end region and/or at the rear end region which protrude in a substantially vertical direction from the upper side of the shoe sole. Thereby, a circumferential railing structure connects at least partially the at least six rib-shaped protrusions with one another, wherein at least six connection slots are formed between the rib-shaped protrusions and the upper side of the main body and a lower side of the circumferential railing structure. The at least six connection slots are adapted for mounting connection elements of an upper material in a loop-like manner at the circumferential railing structure.

[0009] Generally, the term “shoe sole” comprises all sorts of shoe, sandal or slipper bottoms which may be used to support and/or protect human foot soles, i.e. particularly when walking. The shoe sole may comprise all sorts of materials, as for example plastics, leather, cork, wood, rubber or the like, i.e. alone or in combination.

[0010] The term “upper material” comprises all sorts of material which are used to cover the upper side and the side portions of a human foot, i.e. plastics, fabrics, leather, rubber which may be provided in form of full covers, half covers, straps, belts, strips, bands or strings or the like, i.e. alone or in combination. [0011] The term “main body” as used herein substantially includes the part of the shoe sole upon which the foot rests. The circumferential railing structure and the rib-shaped protrusions protrude from and are not part of the main body. The main body however may also include a circumferential edge which at least partially protrudes above the upper side of the shoe sole. In such a case the connection slots are not flush with the upper side of the shoe sole but are arranged between the circumferential railing structure and the circumferential edge.

[0012] The “circumferential railing structure” forms together with the “rib-shaped protrusions” a banister-like arrangement around the shoe sole, preferably along the outer circumference of the shoe sole.

[0013] The term “connection slot” refers to those portions of the shoe sole where the upper material is connected with the shoe sole.

[0014] The term “loop-like manner” as used herein generally defines a mounting type where generally a part of a mounting element is pulled through a connection slot (usually from the inside) guided around the circumferential railing structure and attached at the circumferential railing structure and/or another portion of the mounting element (i.e. as for example a velcro strap which is pulled through the connection slot and is re-attached with a corresponding counter velcro pad at its outer side, thereby forming a loop around the circumferential railing structure; however clips or rings are also conceivable for providing a loop-like mounting). In order to provide interchangeability, the loop is usually reversible; however fixed solutions are also conceivable.

[0015] The term “connection elements of an upper material” includes that the connection elements (i.e. in form of straps as for example velcro straps) form part of the upper material or are produced separately from the upper material and attached to the latter in a subsequent step.

[0016] Thus, by means of the shoe sole according to the present invention, it may be achieved that upper material may be applied to the foot and adjusted from all sides in a completely variable manner, e.g. depending on the respective shape of the foot, possible pressure marks, swellings or other problem zones and the like. This means that the inventive shoe sole is also applicable for operated feet, feet with hallux valgus and feet with similar orthopedic problems. [0017] Preferably, along the outer circumference of the upper side of the main body there are arranged at least eight, preferably at least ten and more preferably at least twelve rib-shaped protrusions at the right-hand side region, at the left-hand side region, at the front end region and/or at the rear end region. Likewise, preferably at least eight, preferably at least ten and more preferably at least twelve connection slots are formed between the rib-shaped protrusions and the upper side of the main body and a lower side of the circumferential railing structure. In this manner, an optimum degree of variability and stability may be achieved.

[0018] Preferably, the circumferential railing structure is arranged substantially parallel to the upper side of the main body. In this manner, a particularly precise adjustment of connection elements of the upper material (e.g. belts, straps, rings, velcro elements and the like) is achieved.

[0019] Preferably, the ratio of height to length of at least two of the connection slots is at least 1 :25, preferably at least 1 :15, further preferably at least 1 :10 and still further preferably 1 :4. Hereby, a high degree of particularly lateral moveability is provided and thus a unique flexibility for all sorts of adjustment requirements, e.g. orthopaedic or fashion-related adoptions of the upper material. In this manner, the connections slots may be configured for a moveable connection of upper material.

[0020] In this context, the term “moveable connection” means that the connection slots comprise a configuration which allows that the upper material is attached in or at the connection slots (i.e. by means of connection elements as for example rings, hooks, loops, slings, laces and the like) such that there remains sufficient play for adjusting the upper material or at least portions thereof within the connection slot, e.g. by laterally displacing the connection elements of the upper material within the connection slots. In this manner, a flexible connection is provided due to highly variable and adjustable attachment points.

[0021] Preferably, the at least six rib-shaped protrusions are arranged in a substantially mirror symmetrical manner. Such arrangement may ultimately provide for a uniform force distribution across the side portions and the upper side of the foot. [0022] Preferably, at the front region of the main body two rib-shaped protrusions are arranged. This configuration of the front region of the shoe sole provides for advantageous stability characteristics.

[0023] Preferably, at the right-hand side region of the main body and at the left-hand side region of the main body at least three rib-shaped protrusions, preferably at least four rib-shaped protrusions and more preferably at least five rib-shaped protrusions, are arranged, respectively. In this manner particularly efficient connection and adjustment options are enabled.

[0024] Preferably, at the rear end region of the main body one rib-shaped protrusion, preferably two rib-shaped protrusions, are arranged, wherein preferably the rib-shaped protrusions at the rear end region of the main bod comprise a greater width than the ribshaped protrusions at the front end region of the main body. Hereby, a high degree of stability is provided in the heel region of the foot.

[0025] In a further preferred embodiment, at least two rib-shaped protrusions are arranged in the rear end region of the main body which preferably comprise a smaller length than the neighboring connection slots. In this manner, still sufficient stability may be provided together with a higher degree of flexibility in the heel region of the foot.

[0026] Preferably, the circumferential railing structure comprises a rectangular, square, polygonal, oval or circular cross-section. These cross-sectional forms have proven to be particularly efficient. The specific configuration however depends on the upper material respectively the connection elements of the upper material.

[0027] Preferably the rib-shaped protrusions comprise a rectangular, square, polygonal, oval or circular shape. Also here, these cross-sectional forms are particularly efficient. The specific configuration however depends on the upper material respectively the connection elements of the upper material.

[0028] Preferably, the upper side of the main body comprises a recess configured to receive a corresponding insole (which may also be referred to herein as inner sole) therein. In this manner additional comfort respectively orthopaedic functions may be provided. [0029] Preferably, the in the front region of the main body a thong is arranged which is preferably connected to the right-hand side region of the main body and to the left-hand side region of the main body by means of connection straps. This embodiment is particularly effective for a flip-flop solution. The thong is preferably placed between the big toe and the pointer toe.

[0030] Preferably, the circumferential railing structure forms a closed railing around the outer circumference of the shoe sole. Hereby, the maximum variability may be provided for attaching upper material.

[0031] Preferably, an at least partially circumferential edge is arranged between an underside of the connection slots and the upper side of the shoe sole. In this manner mounting of the connections elements/straps may be facilitated.

[0032] Preferably, the shoe sole comprises an inner portion and an outer portion wherein the outer portion in particular comprises the rib-shaped protrusions and the circumferential railing structure. In this manner different materials may be combined with advantageous properties.

[0033] Preferably, the shoe sole comprising the inner portion and the outer portion is formed by means of two component injection molding. This has proven to be a very effective production method.

[0034] Preferably, the inner portion is formed by a first plastic material component and the outer portion is formed by a second plastic material component wherein the second plastic material component is harder than the first plastic material component. In this manner, a higher force resistance can be achieved in particular at the rib-shaped protrusions and the circumferential railing structure.

[0035] Preferably, the first plastic material component comprises a Shore hardness between about 40 Shore A and about 75 Shore A, preferably between about 50 Shore A and about 70 Shore A, and the second plastic material component comprises a Shore hardness between about 60 Shore A and about 90 Shore A, preferably between about 70 Shore A and about 80 Shore A. In this manner, a particularly fine-tuned material combination may be provided. [0036] Preferably, first plastic material component comprises a tensile strength between about 500 kPa and about 700 kPa, preferably about 600 kPa, and the second plastics material component comprises a tensile strength between about 15 MPa and about 40 MPa, preferably between about 20 MPa and about 35 MPa. In this manner, the force resistance at the rib-shaped protrusions and the circumferential railing structure can be further enhanced.

[0037] As a preferred material for the first plastic component, expanded thermoplastic polyurethane (E-TPLI) is used, as for example Infinergy® (by BASF), and as a preferred material for the second plastic component a thermoplastic polyurethane (TPU) is used, as for example ESTANE® TEX TPU (by Lubrizol).

[0038] A further aspect of the present invention is directed to footwear comprising a shoe sole as described herein and a corresponding insole wherein preferably the insole includes circumferential connection slits configured for connection of upper material thereto. In this manner, the fitting of the shoe sole may be further improved. This is for example of particular interest for persons with narrow respectively slender feet.

[0039] Preferably, the insole further includes a through-hole for a thong. This is particularly advantageous for an intended use as flip-flops.

[0040] Preferably, the insole comprises at its lower side attachment means configured for being attached to the upper side of the main body of the shoe sole, the shoe sole preferably corresponding receiving means configured to receive the attachment means of the insole for providing a secure hold. In this manner, a particularly strong connection between insole and shoe sole may be achieved.

[0041 ] In another aspect there is provided footwear which comprises a walking sole and an insole, wherein the insole comprises circumferential connection slits configured for connection of upper material thereto and attachment means at its lower side configured for being attached to the walking sole. This embodiment enables using an insole to which the upper material is connected by means of e.g. velcro straps, together with in particular lighter walking soles as for instance walking soles for slippers respectively indoor footwear.

[0042] In still a further aspect of the invention, there is provided footwear comprising a shoe sole as described above and an upper material connected by means of connections elements to the circumferential railing structure of the shoe sole in a loop-like manner at the at least six connection slots, respectively. The connection elements (i.e. in form of straps as for example velcro straps) may form part of the upper material or may be produced separately from the upper material and attached to the latter in a subsequent step.

Brief of the

[0043] The shoe sole respectively foot wear according to the present invention is described in more detail herein below by way of exemplary embodiments and with reference to the attached drawings, in which:

Fig. 1 illustrates a perspective top view of a shoe sole according to the present invention;

Fig. 2 illustrates a perspective side view of a shoe sole according to the present invention;

Fig. 3 illustrates a perspective frontal view of a shoe sole according the present invention;

Fig. 4 illustrates a perspective rear view of a shoe sole according to the present invention;

Fig. 5 illustrates a top view of an exemplary insole which may be used together with the shoe sole according to the present invention;

Fig. 6 illustrates a top view of a further exemplary insole which may be used together with the shoe sole according to the present invention;

Fig. 7 illustrates a perspective top view of footwear which comprises a shoe sole according to the present invention and an exemplary insole;

Fig. 8 illustrates a top view of a further exemplary insole which may be used together with the shoe sole according to the present invention;

Fig. 9 depicts a bottom view of the insole according to Fig. 8; Fig. 10 depicts another example of footwear with a walking sole and an insole according to Figs. 8 and 9;

Fig. 11 shows a perspective rear view of another preferred embodiment of a shoe sole according to the present invention;

Fig. 12 illustrates a cross-sectional view of a shoe sole according the present invention and a velcro strip to be mounted thereto;

Fig. 13 illustrates a cross-sectional view of the inventive shoe sole according to Fig. 12 with a fixed velcro strap;

Fig. 14 illustrates a rear view of the inventive shoe sole according to Fig. 13; and

Fig. 15 illustrates a side view of the inventive shoe sole according to Fig. 13. of Embodiments

[0044] In the following description certain terms are used for reasons of convenience and are not intended to limit the invention. The terms “right”, “left”, “up”, “down”, “under" and “above" refer to directions in the figures. The terminology comprises the explicitly mentioned terms as well as their derivations and terms with a similar meaning. Also, spatially relative terms, such as "beneath", "below", "lower", "above", "upper", "proximal", "distal", and the like, may be used to describe one element's or feature's relationship to another element or feature as illustrated in the figures. These spatially relative terms are intended to encompass different positions and orientations of the devices in use or operation in addition to the position and orientation shown in the figures. For example, if a device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be "above" or "over" the other elements or features. Thus, the exemplary term "below" can encompass both positions and orientations of above and below. The devices may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein interpreted accordingly. Likewise, descriptions of movement along and around various axes include various special device positions and orientations. [0045] To avoid repetition in the figures and the descriptions of the various aspects and illustrative embodiments, it should be understood that many features are common to many aspects and embodiments. Omission of an aspect from a description or figure does not imply that the aspect is missing from embodiments that incorporate that aspect. Instead, the aspect may have been omitted for clarity and to avoid prolix description. In this context, the following applies to the rest of this description: If, in order to clarify the drawings, a figure contains reference signs which are not explained in the directly associated part of the description, then it is referred to previous or following description sections. Further, for reason of lucidity, if in a drawing not all features of a part are provided with reference signs it is referred to other drawings showing the same part. Like numbers in two or more figures represent the same or similar elements.

[0046] Fig. 1 shows a perspective top view of an inventive shoe sole 1 . The shoe sole 1 comprises a main body 2 with a longitudinal axis X, an upper side 5 and a lower side 6, with a right-hand side region 7a, a left-hand side region 7b, with a front end region 7c and with a rear end region 7d. Along the outer circumference of the upper side 5 of the main body 2 multiple rib-shaped protrusions 3a, 3b, 3c, 3d, 3e and 3f are arranged. At the righthand side region 7a there is arranged in this embodiment a rib-shaped protrusion 3a, at the left-hand side region 7b a rib-shaped protrusion 3e, at the front end region 7c ribshaped protrusions 3a and 3f and at the rear end region 7d rib-shaped protrusions 3c and 3d. The rib-shaped protrusions 3a, 3b, 3c, 3d, 3e and 3f protrude in a substantially vertical direction Y from the upper 5 side of the shoe sole 1 . A recess 5a for receiving an insole is preferably provided in the upper side 5 of the shoe sole 1 . Lower side 6 may comprise a profile (not shown here).

[0047] Further, a circumferential railing structure 4 connects in this embodiment the ribshaped protrusions 3a, 3b, 3c, 3d, 3e and 3f with one another, wherein connection slots 8a, 8b, 8c, 8d, 8e and 8f are formed.

[0048] Thereby, in the present embodiment, connection slot 8a is formed between the rib-shaped protrusions 3a and 3f and the upper side 5 of the main body 2 and a lower side of the circumferential railing structure 4. Connection slot 8b is formed between the rib-shaped protrusions 3a and 3b and the upper side 5 of the main body 2 and a lower side of the circumferential railing structure 4. Connection slot 8c is formed between the rib-shaped protrusions 3b and 3c and the upper side 5 of the main body 2 and a lower side of the circumferential railing structure 4. Connection slot 8d is formed between the rib-shaped protrusions 3c and 3d and the upper side 5 of the main body 2 and a lower side of the circumferential railing structure 4. Connection slot 8e is formed between the rib-shaped protrusions 3d and 3e and the upper side 5 of the main body 2 and a lower side of the circumferential railing structure 4. Connection slot 8f is formed between the rib-shaped protrusions 3e and 3f and the upper side 5 of the main body 2 and a lower side of the circumferential railing structure 4. In this embodiment, the rib-shaped protrusions 3a, 3b, 3c, 3d, 3e and 3f comprise rectangular or square shapes. Further, the circumferential railing structure 4 comprises a rectangular or a square cross-section in this embodiment.

[0049] In this embodiment, the connection slots 8b and 8f are the connections slots with the greatest length and have the greatest curvature. The connections slots 8c and 8e are the connection slots with the second greatest length. The connection slots 8a and 8d have the third greatest length, wherein the connection slots 8a and 8d comprise about the same length. In a preferred embodiment, the length of connection slot 8d may be greater than length of connection slot 8a and vice-versa, i.e. depending on the intended use of the shoe sole. In this embodiment, connections slots 8a and/or 8d may be provided for tight respectively non-adjustable connections of upper material whereas connections slots 8b, 8c, 8e and 8f are configured for moveable connection of upper material respectively of the corresponding connection elements.

[0050] Fig. 2 illustrates a perspective side view on the inventive shoe sole 1 of Fig. 1 . Exemplarily, it is shown for connection slot 8d that the slot comprises a length L and a height H. The ratio of height H to length L of the connection slot 8d is at least 1 :25, preferably at least 1 :15, further preferably at least 1 :10 and still further preferably 1 :4. It is conceivable that all connection slots comprise these ratios or only some of them. Preferably, connection slots 8a and 8d may comprise greater H:L ratios since the length is usually smaller than the length of lateral connection slots 8b, 8c, 8e and 8f. Usually, height H is the same for all connection slots 8a, 8b, 8c, 8d, 8e and 8f. Yet, in case of profiled shoe soles 1 the height H may vary in the individual connection slots.

[0051] In Fig. 3, a perspective front view of the inventive shoe sole 1 of Fig. 1 is depicted. As can be derived from this figure in context with Figs. 1 and 2, the rib-shaped protrusions 3a and 3f arranged in the front region 7c of the shoe sole 1 comprise a length which is greater than the length of the lateral rib-shaped protrusions 3b and 3e but smaller than the length of connection slot 8a. The rib-shaped-protrusions 3a, 3b, 3c, 3d, 3e and 3f and the connection slots 8a, 8b, 8c, 8d, 8e and 8f are arranged in a mirror-symmetrical manner, i.e. with regard to longitudinal axis X.

[0052] In Fig. 4, a perspective rear view of the inventive shoe sole 1 of Fig. 1 is depicted. As can be derived from this figure in context with Figs. 1 and 2, the rib-shaped protrusions 3c and 3d arranged in the rear region 7d of the shoe sole 1 comprise a length which is greater than the length of the lateral rib-shaped protrusions 3a, 3b, 3e and 3f and greater than the length of connection slot 8d. Also, the rib-shaped protrusions 3c and 3d comprise a curvature which is greater than the curvature of the circumferential railing structure 4 in the area of connection slots 8a and 8f. Preferably, the portion of the circumferential railing structure 4’ arranged between the rib-shaped protrusions 3c and 3d is preferably thinner respectively comprises a smaller height than the rest of the circumferential railing structure 4.

[0053] Fig. 5 is a top view of a pair of insoles 10 (i.e. right insole R and left insole L) wherein each insole comprises circumferential connection slits 11 through which connection straps or bands (e.g. velcro straps) may be guided for achieving an improved or tighter fitting, for example for persons with narrow respectively slender feet. The insoles may comprise a waist and/or may be formed to compensate for possible protrusions or troughs which may be provided in the upper side 5 of the shoe sole 1 , i.e. for achieving specific ergonomic effects when standing or walking.

[0054] Fig. 6 is a top view of an alternative pair of insoles 10 (i.e. right insole R and left insole L) wherein each insole again comprises circumferential connection slits 11. Additionally, the insoles 10 comprise a through-hole 12 configured for passing through a thong which may be provided on an inventive shoe sole 1 . The trough-hole 12 is usually arranged between big toe and pointer toe.

[0055] In Fig. 7 an example of footwear 20 with an inventive shoe sole 1 is shown having a thong 9 and respective thong straps 9a and 9b which are connected exemplarily in connection slots 8b and 8e, i.e. for y-shaped types as for example flip-flops or slim sparkles. The shoe sole 1 comprises an insole 10 according to Fig. 6 above (connection slits have been omitted). In this embodiment rib-shaped protrusions 3a and 3f are spaced further apart than in the embodiment according to Fig. 1 . In other words, in this exemplary embodiment connection slot 8a has a greater length; alternatively further rib-shaped protrusions may be provided in the front region forming additional connection slots, i.e. as long as a moveable connection for the respective upper material may be ensured. Also, one relatively long respectively continuous frontal rib-shaped protrusion may be provided leading to connection slots in the lateral front regions. In the rearward area of the shoe sole 1 , a rear strap 14 is provided which is connected in connection slots 8c and 8e in order to provide a rearward holding element for a foot. Thus, also in this embodiment, connections slots 8b, 8c, 8e and 8f are configured for moveable connection of upper material, respectively.

[0056] Fig. 8 depicts, in top view, a similar pair of insoles 10 (i.e. right insole R and left insole L) as is shown in Fig. 6. On the upper side of the insoles 10 one can see the connection slits 11 , the trough-hole 12 and additionally an attachment means structure 13’. The actual attachment means 13 which are arranged at the lower side of the insoles 10 are illustrated in Fig. 9. The attachment means 13 may for example comprise velcro structures which provide a safe fixation with a corresponding velcro structure arranged at the upper side of the shoe sole 1 . The attachment means 13 may of course comprise any other suitable configuration, as for example magnetic, snap-in or click-in solutions and the like.

[0057] In Fig. 10 another aspect of the insoles 10 according to Figs. 8 and 9 is illustrated. Instead of using the insole 10 with the attachment means 13 and, if applicable, the trough-hole 12 for a thong together with the shoe sole 1 , it is also possible to provide alternative footwear 30 by attaching the insole 10 (with or without through-hole 12) at a walking sole 31 for in particular slippers or indoor footwear. In other words, the waling sole 31 is usually relatively thin and less robust than the shoe sole 1 described above. Again, at the connection slits 31 and/or at one or more of the attachment means 13 straps which enclose a foot may be connected (for example as velcro systems). In this manner, it is enabled that the insole 10 may be taken out of a shoe sole 1 or out of any sort of shoe in order to use the latter as slipper, indoor footwear or summer sandal. In other words, such variable insole is transformable into light footwear.

[0058] Finally, Fig. 11 illustrates in a perspective rear view another preferred embodiment of an inventive shoe sole 1. Here, four rib-shaped protrusions 3c, 3d, 3d’ and 3d” are arranged in the rear region 7d of the shoe sole 1 which comprise a length which is smaller than the length of the rear rib-shaped protrusions shown in Fig. 4 but still greater than the length of the lateral rib-shaped protrusions. Yet, in this embodiment, the length of the rib-shaped protrusions 3c, 3d, 3d’ and 3d” is preferably smaller than the length of connection slot 8d. Preferably, the portion of the circumferential railing structure 4’ arranged between the rib-shaped protrusions 3c and 3d’, between 3d’ and 3d and between 3d and 3d” is preferably thinner respectively comprises a smaller height than the rest of the circumferential railing structure 4. Usually, connection slots 8d, 8d’ and 8d” comprise about the same length. It is however also conceivable that connection slot 8d comprises either a smaller length than connection slots 8d’ and 8d” or a greater length than connection slots 8d’ and 8d” (i.e. depending on the actual application of the shoe sole 1 ). Advantageously, the rib-shaped protrusions 3d and 3d’ comprise a smaller length than the neighboring connection slots 8d, 8d’ and 8d”.

[0059] In Fig. 12, a cross-sectional view of an inventive shoe sole 1 being formed of an outer portion 1 b and an inner portion 1a, e.g. by means of two component injection molding process as one piece. The outer portion 1 b in particular comprises the rib-shaped protrusions and the circumferential railing structure 4, as well as an outsole 19. The main body 2 comprises the inner portion 1a and the outer portion 1 b up to the upper side 5 including circumferential edge 17. The shoe sole 1 is illustrated together with a rear strap 15 having a velcro pad 16a and a velcro counter pad 16b which shall be mounted at connection slot 8d’ of shoe sole 1. By means of the arrows it is depicted how the strap 15 shall be mounted in form of a loop around the circumferential railing structure 4 above connection slot 8c.

[0060] Fig. 13 shows the inventive shoe sole 1 of Fig. 12 with rear strap 15 being mounted at the circumferential railing structure 4 above connection slot 8c (see in particular the detail view). The velcro counter pad 16b has been pulled through connection slot 8c from the inner side, guided around circumferential sailing structure 4 and attached at velcro pad 16a. Between the underside Su of the connection slot 8d’ and the upper side 5 of the shoe sole 1 the at least partially circumferential edge 17 is arranged. Usually, the circumferential edge 17 is arranged below all of the connections slots; however, it is generally possible that the underside Su of all or of some of the connections slots is flush with the upper side 5 of the shoe sole 1 .

[0061] Fig. 14 shows a rear view of an inventive shoe sole 1 with rear strap 15 visible behind connection slot 8d’. Velcro pad 16a and velcro counter pad 16b provide for an efficient, reliable and interchangeable mounting of rear strap 15 (and the respective upper material connected thereto) at the circumferential railing structure 4. Rib-shaped protrusion 3d is arranged between connection slot 8d and connection slot 8d’. [0062] In Fig. 15, a side view of the outer portion 1b of the inventive shoe sole 1 is shown with eight lateral connection slots 8d’, 8c, 8c’, 8c”, 8b, 8b’, 8b” and 8b’” which provide for an enhanced flexibility for mounting different types of upper material by means of velcro straps or other suitable connection means which ensure interchangeability and a secure mounting, rear strap 15 forms a loop around circumferential railing structure 4 at connection slot 8c which arranged between rib-shaped protrusions 3c and 3c’. The velcro pad 16 and velcro counter pad 16a are attached to one another in a relatively short distance above circumferential railing structure 4. Reference number 18 schematically represents an upper material which is connected by means of strap 15 to connection slot 8c (exemplarily). Thereby, strap 15 may form part of the upper material 18 or may be made of separate material which is attached to strap 15.

[0063] This description and the accompanying drawings that illustrate aspects and embodiments of the present invention should not be taken as limiting-the claims defining the protected invention. In other words, while the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. Various mechanical, compositional, structural, electrical, and operational changes may be made without departing from the spirit and scope of this description and the claims. In some instances, well-known circuits, structures and techniques have not been shown in detail in order not to obscure the invention. Thus, it will be understood that changes and modifications may be made by those of ordinary skill within the scope and spirit of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below.

[0064] The disclosure also covers all further features shown in the figures individually although they may not have been described in the afore or following description. Also, single alternatives of the embodiments described in the figures and the description and single alternatives of features thereof can be disclaimed from the subject matter of the invention or from disclosed subject matter. The disclosure comprises subject matter consisting of the features defined in the claims or the exemplary embodiments as well as subject matter comprising said features.

[0065] Furthermore, in the claims the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single unit or step may fulfil the functions of several features recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. The terms “essentially”, “about”, “approximately” and the like in connection with an attribute or a value particularly also define exactly the attribute or exactly the value, respectively. The term “about” in the context of a given numerate value or range refers to a value or range that is, e.g., within 20%, within 10%, within 5%, or within 2% of the given value or range. Components described as coupled or connected may be electrically or mechanically directly coupled, or they may be indirectly coupled via one or more intermediate components. Any reference signs in the claims should not be construed as limiting the scope.

List of reference numbers:

1 shoe sole

1 a inner portion (two component)

1 b outer portion (two component)

2 main body (one component)

3a-f rib-shaped protrusions

4 circumferential railing structure

4’ circumferential sealing structure at 8d

5 upper side

5a recess

6 lower side

7a right-hand side region

7b left-hand side region

7c front end region

7d rear end region

8a-f connection slots

9 thong

9a-b thong straps

10 insoles

11 connection slits

12 through-hole

13 attachment means

13’ attachment means structure (sole upper side)

14 rear strap (upper material)

15 rear strap (upper material)

16a velcro pad

16b velcro counter pad

17 circumferential edge (at least partially)

18 upper material

19 outsole

30 footwear

31 walking sole

H height

L length

Su underside connection slots

X longitudinal axis Y vertical axis