Footwear with detachable sole

Abstract

NOT VISIBLE DUE TO STATUS OF PATENT

Description

[0001] FOOTWEAR WITH DETACHABLE SOLE

[0002] CROSS-REFERENCE(S) TO RELATED APPLICATIONS

[0003] This application claims priority from South African provisional patent application number 2023 / 09306 filed on 5 October 2023, which is incorporated by reference herein.

[0004] FIELD

[0005] The present invention relates to foot coverings with parts that can be assembled and replaced by a user, such as an end-user. In particular, the present invention relates to shoes, boots, sandals and the like which are configured for assembly in such a way as to provide a removable and replaceable sole and tread.

[0006] BACKGROUND

[0007] Footwear is typically manufactured by securing a shoe upper to a shoe sole using a strong adhesive and / or by sewing with an industrial machine. However, industrial-grade adhesives can be messy to use and require following proper safety precautions such as wearing protective gear and providing ventilation as they may cause skin, eye, and respiratory irritation. Industrial sewing machines and other machines used in the manufacturing process of shoe assembly are expensive and increase the cost of manufacturing.

[0008] The treads of shoes wear down over time with use. After time, a shoe typically becomes unusable or at least hazardous to use since the tread surface no longer provides sufficient grip and / or may be worn too thin to protect from sharp objects on the ground. However, the upper of the shoe tends to last longer and is often still in good condition when the tread is worn down. Due to factors such as the time, effort and expense of repairing the tread, users generally discard the worn-out shoes and replace them with a new pair. This leads to wastage of shoes that still have potential use and leaves the incentive to take care of shoes remaining to be seen.

[0009] There is accordingly scope for improvement.

[0010] The preceding discussion of the background is intended only to facilitate an understanding of the present disclosure. It should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was part of the common general knowledge in the art as at the priority date of the application. SUMMARY

[0011] In accordance with a first aspect of the invention there is provided a foot covering, comprising: an upper component, a midsole attachable to the upper component to define a foot-receiving zone in use, and a tread part, wherein the midsole has a first major surface having a first set of mating formations defined thereon, and the tread part is removably attachable to the midsole by way of a second set of mating formations defined on a first major surface of the tread part, the second set of mating formations being configured to cooperate with the first set of mating formations to removably attach the midsole to the tread part.

[0012] The first set of mating formations and the second set of mating formations may be configured to cooperate to removably attach the midsole to the tread part by way of a form-fit connection.

[0013] Each of the first set of mating formations and the second set of mating formations may include a plurality of protrusions spaced apart from each other, wherein protrusions of at least one of the first and second sets of mating formations are at least partially resiliently deformable.

[0014] Each of the protrusions may have an elongate stem terminating in a head. The head may be disc shaped. The heads of the protrusions on the tread part and the heads of the protrusions on the midsole may be configured to be captured by each other when the tread part is pressed against the midsole with the heads on the tread part and the heads on the midsole facing each other.

[0015] A surface of the stem of each protrusion may be hyperboloid. The head of each protrusion may have rounded edges. The head of each protrusion may have a central bore.

[0016] The heads of the protrusions on the tread part may be configured to be received by first head spaces defined by adjacent heads of the protrusions on the midsole and may be configured to be retained in first stem spaces defined by adjacent stems of the protrusions on the midsole, and wherein the heads of the protrusions on the midsole may be configured to be received by second head spaces defined by adjacent heads of the protrusions on the tread part and may be configured to be retained in second stem spaces defined by adjacent stems of the protrusions on the tread part, wherein the heads of the protrusions are received by the head spaces by way of urging the heads of the respective parts against each other to deform the protrusions so as to expand the head spaces and allow entry of the heads into the head spaces.

[0017] The heads of the protrusions on the tread part may have a maximum diameter larger than a maximum diameter of the first head spaces at rest and equal to or smaller than a maximum diameter of the first stem spaces, and wherein the heads of the protrusions on the midsole may have a maximum diameter larger than a maximum diameter of the second head spaces at rest and equal to or smaller than a maximum diameter of the second stem spaces.

[0018] The tread part may be removable from the midsole with a pulling force applied to the tread part such that the protrusions on the tread part are removed from the first stem spaces and the protrusions of the midsole are removed from the second stem spaces.

[0019] The foot covering may include a guide arrangement provided by a first guide formation located on the tread part and a second guide formation located on the midsole, the first and second guide formations being configured to align the tread part and the midsole for attachment to each other.

[0020] Engagement of the first guide formation with the second guide formation may provide a seal between the tread part and the midsole.

[0021] The protrusions on the tread part may be located relative to the first guide formation on the tread part, and the protrusions on the midsole may be located relative to the second guide formation on the midsole such that when the first and second guide formations are aligned, the protrusions on the tread part and the protrusions on the midsole are offset relative to each other to allow the heads of the protrusions on the tread part and the heads of the protrusions on the midsole to capture each other when pressed together.

[0022] The first guide formation may be one of a mortise and a tenon and the second guide formation is the other of the tenon and the mortise, the mortise being configured to receive the tenon in use.

[0023] The midsole may include a mound formation extending from a second major surface thereof.

[0024] The upper component may include a lip configured to be captured by a cooperating formation of the midsole.

[0025] The cooperating formation may be a recess defined in an inner sidewall of a rim formation provided on a perimeter of the second major surface of the midsole.

[0026] The lip may include a fold shaped to cooperate with the mound formation such that the fold lies on the mound formation of the midsole when the lip is captured by the cooperating formation. The foot covering may include accommodating formations defined in the second major surface of the midsole configured to accommodate overlapping portions of the upper component. The accommodating formations may be located near a perimeter of the midsole within the cooperating formation.

[0027] The upper component, the midsole, and the tread part are configured to be secured together with stitching. The stitching may be hand stitching. The upper component, the midsole and the tread part include stitching apertures configured to be aligned to each other and joined by the stitching.

[0028] The stitching apertures may include a first set of stitching apertures including a series of stitching apertures having an entry defined on a first side of the fold of the lip and extending through the midsole to an exit defined in a tip of the mortise such that the upper component is securable to the midsole.

[0029] The tread part may include grip formations defined in a second major surface thereof, the grip formations being configured to provide grip in use.

[0030] The foot covering may include an elongate groove provided near and extending along a perimeter of the second major surface of the tread part, and a second set of stitching apertures including a series of stitching apertures having an entry defined on a second side of the fold of the lip and extending through the midsole and the tread part to an exit defined in the elongate groove such that the upper component is secured to the midsole and to the tread part.

[0031] The tread part may include a heel tread part having a second set of heel mating formations and a toe tread part having a second set of toe mating formations, and the midsole may include a first set of heel mating formations corresponding to the second set of heel mating formations and a first set of toe mating formations corresponding to the second set of toe mating formations.

[0032] The foot covering may include a heel tread part coupling arrangement provided by a first heel tread part coupling means located on the heel tread part and a second heel tread part coupling means located on the midsole, the first and second heel tread part coupling means being configured to cooperate to couple the heel tread part to the midsole across a width of the midsole.

[0033] The first heel tread part coupling means may be an elongate tongue extending from an edge of the heel tread part and the second heel tread part coupling means is an elongate groove defined in the portion of the midsole which provides the heel, the elongate groove being configured to receive the elongate tongue to couple the heel tread part to the midsole. The foot covering may include a toe tread part coupling arrangement provided by a first toe tread part coupling means located on the toe tread part and a second toe tread part coupling means located on the midsole, the first and second toe tread part coupling means being configured to cooperate to couple the toe tread part to the midsole across a width of the midsole.

[0034] The first toe tread part coupling means may be provided by two elongate members extending from an edge of the toe tread part, and the second toe tread part coupling means may be provided by two elongate cavities defined in the portion of the midsole which provides the heel, each of the elongate cavities being configured to receive a cooperating elongate member to couple the toe tread part to the midsole.

[0035] The foot covering may include a retaining arrangement configured to retain the toe tread part on the midsole, the retaining arrangement being provided by a first retaining formation located on a first major surface of the toe tread part and a second retaining formation provided on a surface of the midsole between the first set of heel mating formations and the first set of toe mating formations.

[0036] The first and second sets of mating formations may be formed of thermoplastic rubber, wherein the protrusions may be formed of thermoplastic rubber having a Shore of between 70 and 90; wherein the protrusions may be formed of thermoplastic rubber having a Shore of between 75 and 85; wherein the protrusions may be formed of thermoplastic rubber having a Shore of between 78 and 82.

[0037] The first set of mating formations may be integrally formed with the midsole and the second set of mating formations may be integrally formed with the tread part.

[0038] In accordance with another aspect of the invention there is provided a method of assembling a foot covering, comprising: providing an upper component and a midsole attachable to the upper component to define a foot-receiving zone in use, the midsole having a first set of mating formations defined on a first major surface thereof; providing a tread part removably attachable to the midsole by way of a second set of mating formations defined on a first major surface of the tread part, the second set of mating formations being configured to cooperate with the first set of mating formations to attach the midsole to the tread part by way of a form-fit connection; bringing into contact the first set of mating formations of the midsole with the second set of mating formations of the tread part; and, pressing together the midsole and the tread part to cause engagement of the first and second sets of mating formations to removably attach the tread part to the midsole.

[0039] The step of pressing together the midsole and the tread part to cause engagement of the first and second sets of mating formations may generate a form-fit connection to removably attach the tread part to the midsole.

[0040] The method may include a step of aligning a guide arrangement which is configured to align the midsole and the tread part before the step of pressing together the midsole and the tread part.

[0041] The step of attaching the upper component to the midsole may include capturing a lip of the upper component in a cooperating formation on a second major surface of the midsole.

[0042] The method may include securing the upper component, the midsole, and the tread part with stitching via stitching apertures provided in each of the upper component, the midsole and the tread part.

[0043] In accordance with a further aspect of the invention there is provided a tread part for a foot covering, comprising: a first major surface having a second set of mating formations defined thereon, the second set of mating formations being configured to cooperate with a first set of mating formations defined in a midsole to removably attach the tread part to the midsole

[0044] Embodiments of the technology will now be described, by way of example only, with reference to the accompanying drawings.

[0045] BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In the drawings:

[0047] Figure 1 is a side view of an example embodiment of a foot covering with a heel tread part and a toe tread part removably attached to a midsole, with the midsole and tread parts being shown in section view to illustrate interlocking protrusions thereof;

[0048] Figure 2 is a side view of the foot covering of Figure 1 with the heel tread part and toe tread part detached from the midsole, with the midsole and tread parts being shown in section view; Figure 3 is a three-dimensional view of the foot covering of Figure 1 looking from the top down through the upper component and midsole to illustrate the interlocking protrusions of the midsole and tread parts respectively;

[0049] Figure 4 is a top down view through a section of the midsole of the foot covering of Figure 1 which illustrates protrusions provided thereon;

[0050] Figure 5 is a top down view of the heel and toe tread parts of the foot covering of Figure 1 ;

[0051] Figure 6 is the same as Figure 3 but shows the tread parts detached from the midsole;

[0052] Figure 7 is a bottom view of the midsole including protrusions of the tread parts to illustrate cooperation of the protrusions with each other when the tread parts (not shown) are removably attached to the midsole of the foot covering of Figure 1 ;

[0053] Figure 8 is a schematic section view of a toe part of an upper component which illustrates features of an example embodiment of an upper component of a foot covering according to aspects of the present disclosure;

[0054] Figure 9 is a schematic section view of a heel part of an upper component which illustrates features of an example embodiment of an upper component of a foot covering according to aspects of the present disclosure;

[0055] Figure 10 is a schematic section view of a toe part of a midsole which illustrates features of an example embodiment of a midsole of a foot covering according to aspects of the present disclosure;

[0056] Figure 11 is a schematic section view of a heel part of a midsole which illustrates features of an example embodiment of a midsole of a foot covering according to aspects of the present disclosure;

[0057] Figure 12 is a schematic section view of a toe tread part of a tread part which illustrates features of an example embodiment of a tread part of a foot covering according to aspects of the present disclosure; Figure 13 is a schematic section view of a heel tread part of a tread part which illustrates features of an example embodiment of a tread part of a foot covering according to aspects of the present disclosure;

[0058] Figure 14 is a schematic section view of the toe part of the upper component of Figure 8, the toe part of the midsole of Figure 10, and the toe tread part of Figure 12 secured together;

[0059] Figure 15 is a schematic section view of the heel part of the upper component of Figure 9, the heel part of the midsole of Figure 11, and the heel tread part of Figure 13 secured together;

[0060] Figure 16 is a three-dimensional schematic section view of an upper component secured to a midsole to illustrate the stitching details of an example embodiment of an upper component and a midsole of a foot covering according to aspects of the present disclosure;

[0061] Figure 17 is a schematic exploded three-dimensional section view of the toe part of the upper component of Figure 8, the toe part of the midsole of Figure 10, and the toe tread part of Figure 12 positioned to be secured together;

[0062] Figure 18 is a schematic exploded three-dimensional section view of the toe part of the upper component of Figure 8, the toe part of the midsole of Figure 10, and the toe tread part of Figure 12 positioned closer to each other to be secured together;

[0063] Figure 19 is a schematic three-dimensional section view of the toe part of the upper component of Figure 8, the toe part of the midsole of Figure 10, and the toe tread part of Figure 12 secured together;

[0064] Figure 20 is a schematic exploded three-dimensional section view of the heel part of the upper component of Figure 9, the heel part of the midsole of Figure 11 , and the heel tread part of Figure 13 positioned to be secured together;

[0065] Figure 21 is a schematic exploded three-dimensional section view of the heel part of the upper component of Figure 9, the heel part of the midsole of Figure 11 , and the heel tread part of Figure 13 positioned closer to each other to be secured together;

[0066] Figure 22 is a schematic three-dimensional section view of the heel part of the upper component of Figure 9, the heel part of the midsole of Figure 11 , and the heel tread part of Figure 13 secured together;

[0067] Figure 23 is a schematic section view of a tread part removably attached to a midsole to illustrate the interlocking protrusions of an example embodiment of a midsole and an example embodiment of a tread part, respectively, of a foot covering according to aspects of the present disclosure;

[0068] Figure 24 is a schematic section view of a protrusion of a midsole which illustrates features of an example embodiment of a midsole of a foot covering according to aspects of the present disclosure;

[0069] Figure 25 is a schematic top view of a midsole removably attached to a tread part to illustrate cooperation of the protrusions with each other when the tread part is removably attached to the midsole of a foot covering according to aspects of the present disclosure;

[0070] Figure 26 is a top view of a heel tread part and a toe tread part which illustrates features of an example embodiment of a tread part of a foot covering according to aspects of the present disclosure;

[0071] Figure 27 is a top view of a midsole which illustrates features of an example embodiment of a midsole of a foot covering according to aspects of the present disclosure;

[0072] Figure 28 is a bottom up view through a section of the tread part of Figure 26 attached to the midsole of Figure 27;

[0073] Figure 29 is a side view of a foot covering according to aspects of the present disclosure with the heel tread part and a toe tread part of Figure 26 removably attached to the midsole of Figure 27, with the midsole and tread parts being shown in section view taken along line XXIX - XXIX of Figure 28 to illustrate the coupling of the tread parts to the midsole via the first and second coupling arrangements; Figure 30 is the same as Figure 29 but shows the tread parts detached and uncoupled from the midsole;

[0074] Figure 31 is a side view of a foot covering according to aspects of the present disclosure with the heel tread part and the toe tread part of Figure 26 removably attached to the midsole of Figure 27, with the midsole and tread parts being shown in section view taken along line XXXI - XXXI of Figure 28 to illustrate the coupling of the tread parts to the midsole via the first and second coupling arrangements;

[0075] Figure 32 is the same as Figure 31 but shows the tread parts detached and uncoupled from the midsole;

[0076] Figure 33 is a top view of a midsole which illustrates accommodating formations of an example embodiment of a midsole of a foot covering according to aspects of the present disclosure; and

[0077] Figure 34 is a schematic three-dimensional section view of the midsole of Figure 33.

[0078] DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

[0079] Embodiments of a foot covering are disclosed. The foot covering may be a shoe, a sandal, a boot or any other suitable form of footwear. The foot covering is made of several parts that are attachable to each other in such a way that an end-user (or wearer) can assemble and replace parts of the shoe him- or herself. The foot covering parts include an upper component, a midsole, and one or more tread parts. The tread part is the outermost component of the foot covering that is in contact with the ground in use. The tread part is provided with mating formations, for example in the form of knobs, stubs or other such formations that are compatible with the corresponding mating formations on the midsole. When engaged, the mating formations on the midsole and the tread part capture and hold each other in place such that movement away from each other is prevented. As a function of the shape and form of the mating formations on the tread part and the midsole, these components may be pressed together to attach them together, and may be pulled apart by the user to detach the tread part. This way, the tread part may be securely attached to the midsole and detached with relative ease as the use of glue is obviated. Therefore, the tread part (and as a result the tread of the foot covering) can be easily replaced by a user when it gets worn out with use of the foot covering due to friction, instead of purchasing a whole new foot covering. This enables a user to extend the lifetime of the foot covering and reduces waste by incentivising user-care of the foot covering.

[0080] The parts also include various features that allow for easy alignment and handling during assembly of the foot covering. The respective parts also include stitching apertures or sewing holes which may be aligned with each other to allow a user to join the components together securely using stitching before wearing the foot covering. The upper component, the midsole, and the tread parts are configured to be secured together with hand stitching which avoids the time and manufacturing cost associated with specialised industrial machinery. The foot covering provides a convenient, easy and cost-effective solution to long-lasting footwear needs.

[0081] An example embodiment of a foot covering (100) is illustrated in Figures 1 to 7. The foot covering (100) includes an upper component (110), a midsole (120), and a tread part (140) which, in Figure 1 , is comprised of a toe tread part (147) and a heel tread part (149) which are removably attached to the midsole. The upper component (110) is attached to the midsole to define a foot- receiving zone which is a region or space in which a user’s foot is placed in use. The upper component may be shaped to cover the whole foot to provide a formal shoe as illustrated in the present embodiment. Other embodiments of the foot covering may be a sneaker or may have an upper component extending above an ankle to provide a boot. The upper component may also be in the form of or provided by one or more straps arranged to attach to the midsole to provide a sandaltype foot covering. The upper component may be made from leather, canvas, polyester, or any other material suitable for a foot covering. In the present embodiment, the tread part (140) is provided as a toe tread part (147) at a toe end (102) of the foot covering and a heel tread part (149) at a heel end (104) of the shoe. Between the toe and heel tread parts is an arch portion (106) to which the tread part does not extend since the arch portion is not expected to experience contact with a walking surface and therefore does not require grip. However, other embodiments of a foot covering may have a tread part extending across the whole midsole, or in other configurations and patterns. The midsole has a first set of mating formations (122) that are configured to engage with a second set of mating formations (142) provided on the tread part. The toe tread part (147) may have a second set of toe mating formations and the heel tread part (149) may have a second set of heel mating formations (collectively the second set of mating formations). The midsole (120) may include a first set of heel mating formations corresponding to the second set of heel mating formations and a first set of toe mating formations corresponding to the second set of toe mating formations (collectively the first set of mating formations). The second set of mating formations of the tread parts (142) may be engaged and connected to the compatible first set of mating formations of the midsole (122) such that the toe tread part (147) and heel tread part (149) can be securely joined to the midsole (120). The first set of mating formations may be integrally formed with the midsole and the second set of mating formations may be integrally formed with the tread part.

[0082] Referring to Figure 2, the tread part (140) may be detached from the midsole (120) by disconnecting the second set of mating formations of the toe and heel tread parts (142) captured by the first set of mating formations of the midsole (122). The tread part may be detached from the midsole by the user pulling the toe and heel tread parts in a direction generally axially away from the midsole, resulting in the separation of the first and second sets of mating formations. The midsole may have a first surface or side (124) on which the mating formations (122) are disposed, and a second surface (126) which is located opposite the first surface. The mating formations of the tread part (142) may be disposed on a first surface or side (144) of the tread part (140). The tread part may have a second surface (146) which opposes the first surface and on which grip formations (158) are provided to provide grip with a walking surface in use. In the present embodiment, the first surface of the midsole (124) is the lower surface when the foot covering is an operable orientation (i.e. , with the tread parts on the ground), and the first surface of the tread part (144) is the upper surface. The grip formations (158) may be grooves or indentations or other features defined in or on the tread part that are configured to provide a nonslip functionality. Referring to Figures 3 and 6, one of the grip formations (158) on each side of the tread part (140) may extend further into the tread part to form an elongate groove (154). The elongate groove (154) may be an angular formation that may provide further grip and prolong wear. With extended use of the shoe, the grip formations may wear down, resulting in the tread part having a smooth second major surface which may be a slipping hazard for user. Therefore, the worn-out tread part may be removed from the shoe and replaced with a new tread part by the user.

[0083] Referring to Figures 3 to 7, each of the first set of mating formations on the midsole (122) and the second set of mating formations on the tread part (142) includes a plurality of protrusions provided across at least most of the first surface (124) of the midsole and the first surface (144) of the tread part, respectively. The protrusions may be arranged in straight rows (e.g., as illustrated in Figure 7) or in other suitable patterns.

[0084] In the present embodiment, each protrusion on the midsole consists of an elongate stem (123) extending from the lower surface of the midsole (124) and having a head (125) at the end of the stem (123). Similarly, the protrusions on the tread part consist of an elongate stem (143) extending from the upper surface of the tread part (144) and terminating in a head (145). The protrusions of the tread part and the midsole may be identically shaped and dimensioned. The heads of the midsole protrusions (145) and the heads of the tread part protrusions are identical and are thin, flat and disc shaped. The heads may be a variety of other shapes in other embodiments suitable for providing a form-fit connection such as square or other regular or nonregular polygon, ovoid, or the like. The protrusions may be resiliently deformable. For example, the protrusions may be made from a rubber or other suitable material which is resiliently deformable. In this manner, heads of the protrusions can be urged from their rest positions or conditions off their respective axes by way of radial forces (e.g., causing the stems to bend, arcing the head). Further, heads can be tilted about their respective axes relative to their rest positions or conditions by way of radially displaced axial forces applied to the heads. Being resiliently deformable, the protrusions return to their rest positions or conditions in the absence of such forces. The rubber may be thermoplastic rubber. The thermoplastic rubber may have a Shore of between 70 and 90, or between 75 and 85, or between 78 and 82. In some examples, the thermoplastic rubber has a Shore of 80.

[0085] The form-fit connection is provided by the spacing and configuration of the stems (123) and heads (125) of the midsole in relation to that of the stems (143) and heads (145) of the tread part, as well as their resiliently deformable nature. The term “form-fit connection” as used herein refers to a mechanical connection between two parts, wherein these parts due to their forms interlock and block each other along at least one defined linear or rotational direction. The form-fit connection of the foot covering described herein is provided by the heads (or, in other embodiments, other comparable features) which, in their rest conditions, interlock and block each other along an axial direction. The form-fit connection may be a force-limited form fit connection in that when a force of sufficient magnitude is applied along the axial direction relative to the heads, the stems and / or heads of the protrusions deform or move away from their rest conditions to break the form-fit connection and permit the tread part to be separated from the midsole.

[0086] When the tread part (140) is aligned to the midsole (120) for attachment, the heads (145) of the tread part are configured to be positioned offset to the heads (125) of the midsole. The heads of the midsole are spaced apart so as to define first head spaces (128) between adjacent heads. In the present embodiment, a first head space (128) may be a central space formed by four circular heads (145). The gaps between adjacent stems of the midsole provide first stem spaces (130). Similarly, the heads (145) of the tread part are positioned with second head spaces (128) between adjacent heads. Adjacent stems are disposed spaced apart from each other to provide first stem spaces (130). As mentioned, the heads of the midsole (125) or the heads of the tread part (145) or both may be at least partially resiliently deformable or flexible. The protrusions are provided on the midsole with a spacing selected such that the first head spaces they define are shaped and sized such that they are smaller than the heads (145) on the tread part. In this way, the flexible heads of the tread part (145) may be pushed with a force applied by the user into the first head spaces (128) and past the heads of the midsole (125) by at least partially flexing or otherwise moving away from their rest positions. Once pushed through, the heads (145) of the tread part may return to an unflexed, rest position and may be captured in the first stem spaces (130) of the midsole which are configured to be large enough to accommodate the heads (145). Simultaneously during this process, the heads of the midsole (125) are pushed into the second head spaces (148) of the tread part and past the heads (145) of the tread part where they are housed in the second stem spaces (150) of the tread part. The stems (123) of the midsole protrusions may have a length or height similar or corresponding to (or substantially the same as) the thickness of the heads (145) of the protrusions on the tread part such that the heads (145) are held captive securely in the first stem spaces (130) without significant room for movement along the length of the stems (123). The stems (145) of the tread part protrusions may also be sized relative to the thickness of the heads (125) of the midsole protrusions to prevent a slipping or sliding movement of the head (125) within the second stem spaces (150). As such, the tread part (140) may attach tightly to the midsole (120).

[0087] Once attached, the heads of the midsole (123) and the heads of the tread part (143) may capture each other and block movement away from each other to prevent detachment of the tread part (140) from the midsole (120). This may be achieved by ensuring the partial overlapping of the heads of the midsole (123) and the heads of the tread part (143). To remove the tread part (140) from the midsole (120), a force may be applied to force the heads of the tread part (143) and the heads of the midsole (123) to flex and release themselves from the first stem spaces (130) and second stem spaces (150).

[0088] In some examples, the mating formations are arranged or configured as described below with reference to Figures 23 to 28.

[0089] Referring to Figures 3 to 7, the foot covering may include several features that aid in aligning the upper component (110), the midsole (120) and the tread part (140) to each other during assembly. The second major surface of the midsole (126) may include a cooperating formation (132) configured to capture a lip (112) of the upper component. The cooperating formation (132) may be in the form of a recess (134) at a perimeter (136) of the upper surface of the midsole (126), the recess being shaped and sized to receive and retain the lip (112).

[0090] A guide arrangement (160) may be provided to assist in aligning the midsole and the tread part before the first and second mating formations are pressed together. The guide arrangement (160) may comprise a first guide formation (162) provided on the first major surface of the tread part (144) and a second guide formation (164) provided on the lower or first major surface of the midsole (124). The first guide formation (162) may be a tenon provided by a ridge at the perimeter (152) of the tread part. The second guide formation (164) may be a mortise complementarily shaped and sized to the tenon such that the mortise may receive the tenon in use.

[0091] In some embodiments, the foot covering is provided with one or more of a heal tread part coupling arrangement, a toe tread part coupling arrangement, a retaining arrangement and accommodating formations as described in greater detail below with reference to Figures 26 to 34. In some embodiments, in addition to the mating formations provided to mate the tread parts to the midsole, the foot covering may be configured for stitching the upper component and / or one or more tread parts to the midsole. Features of the foot covering providing this functionality are represented schematically with reference to Figures 8 to 22. The features described below with reference to Figures 8 to 22 may find application in the example foot covering described above with reference to Figures 1 to 7, and vice versa.

[0092] Referring to Figures 8 and 9, a schematic section view of the upper component viewed from the front or toe end (202) of the foot covering and the rear or heel end of the foot covering (204) is shown. The upper component (210) may include a lip (212) running along its periphery. The lip may be a rim or edge extending outward from the periphery of the upper component (210). The lip may include a fold (214) provided in the present embodiment as a rigid, angular bump or crimp.

[0093] Referring to Figures 10 and 11 , the upper or second major surface (226) of the midsole may include a mound formation (222) provided by a bump or crimp shaped complementarily to the fold (214) on the lip (212) of the upper component (210). The fold (214) on the lip (212) is configured to cooperate with and locate on top of the mound formation (222) during assembly to ensure that the upper component (210) is aligned to the midsole (220) when being attached to the midsole during assembly of the shoe. The second major surface of the midsole (226) may also include a cooperating formation (232) configured to capture the lip (212) of the upper component. Such capturing enables easy handling of the components during assembly of the foot covering as the lip (212) is caught by or clipped into place in the cooperating formation (232). The cooperating formation (232) may be provided by a recess or cavity (234) at an edge or perimeter (236) of the upper surface of the midsole (226). The perimeter (236) may include an inwardly extending rim formation (238) having an inner wall (239) in which the recess is defined.

[0094] Referring to Figures 10 to 13, the midsole (220) and tread part (240) may include a guide arrangement (260) configured to align these components during assembly of the foot covering. The guide arrangement may comprise a first guide formation (262) provided on the upper or first major surface of the tread part (244) and a second guide formation (264) provided on the lower or first major surface of the midsole (224). The first guide formation (262) and the second guide formation (264) may be complementarily shaped such that the one fits into the other. In the present embodiment, the first guide formation (262) is a tenon and the second guide formation (264) is a mortise configured to receive the tenon in use. The tenon may be provided as an elongate rim or a series of pins extending from the upper surface of the tread part (244) near a perimeter (252) of the tread part. The pin may have an angled or chamfered top edge with a tip (266) at its highest point. The mortise may be a cavity having a complementary shape to the tenon such that the tenon slots into and fits snugly in the mortise. The tenon and mortise may be shaped and dimensioned to provide a friction or interference fit. The engagement of the mortise and tenon may provide a seal between the midsole and tread part to prevent water or other substances from getting in between these components.

[0095] Referring to Figures 12 and 13, the grip formations (258) on the lower surface of the tread part may be angular grooves disposed across the surface to provide grip with a walking surface. On each side of the tread part (240) may be an elongate groove (254) provided near a perimeter (252) of the tread part. The elongate groove (254) may be angular and extend further into the tread part than the other grip formations. The elongate groove (254) may terminate in a tip (256) at its highest point in the tread part (240).

[0096] Referring to Figures 14 to 22, the foot covering may be assembled by capturing the lip (212) of the upper component (210) in the cooperating formation (232) on the midsole (220) such that the fold of the lip (214) lies on top of the mound formation (222) on the midsole. The midsole may be attached to the tread part (240) by aligning the mortise (264) and tenon (262). The mortise (264) on the midsole and the elongate groove (254) on the tread part may be positioned such that they are at least generally in line with the fold (214) in the upper component when assembled.

[0097] Once the components are positioned correctly, the components may be secured together with stitching (270). The stitching may be hand stitching which may be done with two needles and a thread. Provided on the upper component, the midsole and the tread part are stitching apertures (272) which are pre-punched holes that are configured to be aligned or overlayed to enhance the ease of stitching by the user. A first set of stitching apertures (274) may include a series of stitching apertures (272) having an entry defined on a first side (216) of the fold (214) of the lip and extending through the midsole to an exit defined in a tip of the mortise (268) such that the upper component is securable to the midsole. The first set of stitching apertures (274) may extend from a first aperture or entry defined in the angular lip fold (214) to a last aperture or exit defined in the tip of the mortise (268). The first set of stitching apertures secures the upper component (210) to the midsole (220). Ending the first set of stitching apertures at the tip of the mortise, the highest point of the mortise, protects the thread and reduces the chances of water seeping up the thread.

[0098] A second set of stitching apertures (276) may include a series of stitching apertures having an entry defined on a second side (218) of the fold of the lip (212) and extending through the midsole (220) and the tread part (240) to an exit defined in the elongate groove such that the upper component is secured to both the midsole and to the tread part. The entry may be a first aperture of the second set of stitching apertures (276), and the exit may be a last aperture of the second set of stitching apertures (276). Providing the stitching this way ensures that the stitching will not be compromised by wear of the grip formations (258) since the thread is positioned further into the tread than the grip formations.

[0099] The first set of stitching apertures (274) and the second set of stitching apertures (276) provide a double set of stitching which enables a user to undo only one of these two sets of stitching to release and replace the tread parts with new ones without having to undo any other stitching and disassembling the whole foot covering. Similarly, the user is only required to stitch through these two sets of apertures to secure the new tread parts to the rest of the foot covering. Therefore, the tread parts may be easily replaced by the user to extend the lifetime of the shoe.

[0100] Referring to Figures 23 to 28, in some examples, a surface of the stem (323) of each protrusion of the midsole (320) and a surface of the stem (343) of each protrusion of the tread part (340) may be hyperboloid, meaning having the shape produced by revolving a hyperbola about one of its axes.

[0101] The heads (325) of the protrusions of the midsole (320) and the heads (345) of the protrusions of the tread part (340) may have rounded edges. The rounded edges may be smooth, curved edges as opposed to angular edges. The hyperboloid or hourglass-like shape of the stems and the rounded nature of the edges of each head each inhibit tearing or other damage of the protrusions when removing the midsole or tread part of which the protrusions are part from the manufacturing mould used to manufacture the midsole or tread part, as opposed to edges having a sharper angle, such as 90 degrees which may more easily damaged during manufacturing.

[0102] The heads (325) of the protrusions of the midsole (320) may have a central bore (378). Likewise, the heads (345) of the protrusions of the tread part (340) may have a central bore (380). The central bore may be a cut-out portion formed during moulding of the head which allows the head to collapsibly deform or fold in on itself when demoulding the protrusions from a manufacturing mould and minimise damage to the protrusions such as tearing. The bore allows the surrounding portion of each head to bend into the space provided by the bore during demoulding the protrusions and removing the whole protrusion through the stem-shaped cavity of the mould is narrower in width than the head-shaped cavity of the mould.

[0103] The heads of the protrusions on the tread part (345) may have a maximum diameter smaller than a maximum diameter of the first stem spaces (330) of adjacent midsole stems (323), and likewise, the heads of the protrusions on the midsole (325) may have a maximum diameter smaller than a maximum diameter of the second stem spaces (350) defined by adjacent stems (343) of the protrusions on the tread part (340). The resulting freedom of the heads in their respective stem spaces allows the heads to easily pass each other when the respective parts are pressed together or pulled apart when the user applies a reasonable force to the parts.

[0104] Referring to Figures 26 to 32, in some embodiments, the foot covering may include a heel tread part coupling arrangement (382) to couple the heel tread part (349) to the midsole (320) across a width or lateral axis of the midsole. The heel tread part coupling arrangement may be provided by a first heel tread part coupling means (383) located on the heel tread part (349) and a second heel tread part coupling means (384) located on the midsole (320). The first and second heel tread part coupling means may be configured to cooperate to attach the heel tread part to the midsole. The first and second heel tread part coupling means may be complementarily shaped to allow them to fit together and couple the heel tread part to the midsole. The first heel tread part coupling means may be an elongate tongue extending from an edge of the heel tread part. The edge of the heel tread part may be the edge adjacent the vertical drop of the heel formed in the midsole, where the shoe is a formal-style shoe as illustrated. The elongate tongue may extend from the edge of the heel tread part such that the first heel tread part coupling means has an angular C-shaped cross section. The second heel tread part coupling means may be an elongate groove or notch defined in the heel of the midsole. The elongate groove being shaped and dimensioned to receive the elongate tongue inserted therein to couple the heel tread part to the midsole.

[0105] Similarly, the foot covering may include a toe tread part coupling arrangement (385) to couple the toe tread part (347) to the midsole (320) across a width of the midsole. The toe tread part coupling arrangement may be provided by a first toe tread part coupling means (386) located on the toe tread part and a cooperating second toe tread part coupling means (387) located on the midsole. The first toe tread part coupling means may be two elongate members or extensions extending from an edge of the toe tread part. The second toe tread part coupling means may be two elongate cavities defined in the heel portion of the midsole. Each elongate cavity may be shaped and dimensioned to receive one of the cooperating elongate members in use to couple the toe tread part to the midsole. As seen in Figures 26 and 32, the elongate members in the present embodiment are two rectangular extensions and the elongate cavities are rectangular holes in the midsole configured to receive and hold the extensions therein. The elongate members and cavities may be any suitable shape or size.

[0106] Where both the heel and toe tread part coupling arrangements are provided in the shoe, the elongate cavities of the heel tread part coupling arrangement may be provided operatively above or below the elongate groove of the toe tread part coupling arrangement. The heel and toe tread part coupling arrangements may be provided to avoid the use of stitching across the width of the shoe which may introduce waterproofing issues and points of weakness in the foot covering. The heel and toe tread part coupling arrangements anchor the heel and toe tread parts, respectively, where stitching is only available at a periphery of the midsole and tread parts.

[0107] Referring to Figures 26 to 32, in some embodiments, the foot covering may include a retaining arrangement (388) for retaining the toe tread part (347) on the midsole (320). The retaining arrangement may include a first retaining formation (389) provided on a first major surface of the toe tread part (344) and further include a second retaining formation (390) provided on a surface of the midsole between the first set of heel mating formations and the first set of toe mating formations (collectively, the first set of mating formations (322). The surface of the midsole may be the first major surface (324). The second retaining formation may be configured to cooperate with the first retaining formation to retain the toe tread part on the midsole. The first and second retaining formations may be complementary formations being shaped to fit together. In the present embodiment, the first retaining formation is provided by two adjacent circular sockets defined in a central wedge-shaped cut-out portion in the first major surface of the toe tread part and the second retaining formation is provided by two circular plugs protruding from a wedge- shaped portion of the midsole. The plugs may be configured to snugly fit in the two circular sockets when the toe tread part is pressed against the midsole to attach the toe tread part to the midsole at a point near the middle of the foot covering. Similarly to the central bore of the heads of the protrusions, the two circular plugs in the present embodiment each have a central indentation which is provided to allow the plugs to fold in on themselves to prevent damage to the plugs such as tearing when removing the toe tread part from the manufacturing mould used to manufacture the toe tread part. The retaining arrangement provides a point of attachment between the toe tread part and the midsole at portions thereof where mating formations are absent. In use, the retaining arrangement may be engaged by a user by pressing together or otherwise connecting the first and second retaining formations after engaging the mating formations of the midsole and those of the toe tread part to attach and retain the toe tread part to the midsole. In other embodiments, the first and second retaining formations may be provided by any number of formations such as one, three or more. In other embodiments, the retaining formations may be swapped compared to the embodiment illustrated, whereby the plug is provided on the toe tread part and the socket on the midsole.

[0108] Referring to Figures 33 and 34, in some embodiments, the foot covering may include accommodating formations (391) defined in the second major surface of the midsole (326), the accommodating formations being configured to accommodate overlapping portions of the upper component. The accommodating formations in the present embodiment are rectangular depressions or cut-out portions in midsole. The accommodating formations (391) may be located near a perimeter (336) of the midsole within the cooperating formation (not shown). The accommodating formations prevent bulging of the material of the upper component on the stitch line of stitching apertures (372) where the material of the upper component folds to form two layers if the upper component is formed of a single extent of material, or where the material of two pieces of the upper component overlap to be joined by stitching to provide the upper component. The relatively raised overlapping or folded portions of the upper component compared to the single layer portions of the upper component can be housed within the accommodating formations such that after stitching, the upper component appears smooth without bumps or raised portions at the folds or overlaps which may be unsightly to a consumer.

[0109] The foregoing description has been presented for the purpose of illustration; it is not intended to be exhaustive or to limit the technology to the precise forms disclosed. Persons skilled in the relevant art can appreciate that many modifications and variations are possible in light of the above disclosure.

[0110] The language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the present disclosure be limited not by this detailed description, but rather by any claims that issue on an application based hereon. Accordingly, the present disclosure is intended to be illustrative, but not limiting, of the scope of any accompanying claims.

[0111] Finally, throughout the specification and any accompanying claims, unless the context requires otherwise, the word ‘comprise’ or variations such as ‘comprises’ or ‘comprising’ will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Claims

CLAIMS:

1. A foot covering, comprising: an upper component, a midsole attachable to the upper component to define a foot-receiving zone in use, and a tread part, wherein the midsole has a first major surface having a first set of mating formations defined thereon, and the tread part is removably attachable to the midsole by way of a second set of mating formations defined on a first major surface of the tread part, the second set of mating formations being configured to cooperate with the first set of mating formations to removably attach the midsole to the tread part.

2. The foot covering as claimed in claim 1 , wherein the first set of mating formations and the second set of mating formations are configured to cooperate to removably attach the midsole to the tread part by way of a form-fit connection.

3. The foot covering as claimed in claim 1 or claim 2, wherein each of the first set of mating formations and the second set of mating formations include a plurality of protrusions spaced apart from each other, wherein protrusions of at least one of the first and second sets of mating formations are at least partially resiliently deformable.

4. The foot covering as claimed in claim 3, wherein each of the protrusions has an elongate stem terminating in a head.

5. The foot covering as claimed in claim 4, wherein the heads of the protrusions on the tread part and the heads of the protrusions on the midsole are configured to be captured by each other when the tread part is pressed against the midsole with the heads on the tread part and the heads on the midsole facing each other.

6. The foot covering as claimed in claim 4 or claim 5, wherein a surface of the stem of each protrusion is hyperboloid.

7. The foot covering as claimed in any one of claims 4 to 6, wherein the head of each protrusion has rounded edges.

8. The foot covering as claimed in any one of claims 4 to 7, wherein the head of each protrusion has a central bore.

9. The foot covering as claimed in any one of claims 4 to 8, wherein the heads of the protrusions on the tread part are configured to be received by first head spaces defined byadjacent heads of the protrusions on the midsole and are configured to be retained in first stem spaces defined by adjacent stems of the protrusions on the midsole, and wherein the heads of the protrusions on the midsole are configured to be received by second head spaces defined by adjacent heads of the protrusions on the tread part and are configured to be retained in second stem spaces defined by adjacent stems of the protrusions on the tread part, wherein the heads of the protrusions are received by the head spaces by way of urging the heads of the respective parts against each other to deform the protrusions so as to expand the head spaces and allow entry of the heads into the head spaces.

10. The foot covering as claimed in claim 9, wherein the heads of the protrusions on the tread part have a maximum diameter larger than a maximum diameter of the first head spaces at rest and equal to or smaller than a maximum diameter of the first stem spaces, and wherein the heads of the protrusions on the midsole have a maximum diameter larger than a maximum diameter of the second head spaces at rest and equal to or smaller than a maximum diameter of the second stem spaces.

11. The foot covering as claimed in any one of claims 1 to 10, including a guide arrangement provided by a first guide formation located on the tread part and a second guide formation located on the midsole, the first and second guide formations being configured to align the tread part and the midsole for attachment to each other.

12. The foot covering as claimed in claim 11 , wherein the first guide formation is one of a mortise and a tenon and the second guide formation is the other of the tenon and the mortise, the mortise being configured to receive the tenon in use.

13. The foot covering as claimed in any one of claims 1 to 12, wherein the midsole includes a mound formation extending from a second major surface thereof.

14. The foot covering as claimed in any one of claims 1 to 13, wherein the upper component includes a lip configured to be captured by a cooperating formation of the midsole.

15. The foot covering as claimed in claim 14, wherein the lip includes a fold shaped to cooperate with the mound formation such that the fold lies on the mound formation of the midsole when the lip is captured by the cooperating formation.

16. The foot covering as claimed in any one of claims 1 to 13, including accommodating formations defined in the second major surface of the midsole, the accommodating formations being configured to accommodate overlapping portions of the upper component.

17. The foot covering as claimed in claim 16, wherein the accommodating formations are located near a perimeter of the midsole within the cooperating formation.

18. The foot covering as claimed in any one of claims 1 to 17, wherein the upper component, the midsole and the tread part include stitching apertures configured to be aligned to each other and joined by stitching.

19. The foot covering as claimed in claim 18, wherein the stitching apertures include a first set of stitching apertures including a series of stitching apertures having an entry defined on a first side of the fold of the lip and extending through the midsole to an exit defined in a tip of the mortise such that the upper component is securable to the midsole.

20. The foot covering as claimed in any one of claims 1 to 19, including an elongate groove provided near and extending along a perimeter of a second major surface of the tread part, and a second set of stitching apertures including a series of stitching apertures having an entry defined on a second side of the fold of the lip and extending through the midsole and the tread part to an exit defined in the elongate groove such that the upper component is secured to the midsole and to the tread part.

21. The foot covering as claimed in any one of claims 1 to 20, wherein the tread part includes a heel tread part having a second set of heel mating formations and a toe tread part having a second set of toe mating formations, and wherein the midsole includes a first set of heel mating formations corresponding to the second set of heel mating formations and a first set of toe mating formations corresponding to the second set of toe mating formations.

22. The foot covering as claimed in claim 21 , including a heel tread part coupling arrangement provided by a first heel tread part coupling means located on the heel tread part and a second heel tread part coupling means located on the midsole, the first and second heel tread part coupling means being configured to cooperate to couple the heel tread part to the midsole across a width of the midsole.

23. The foot covering as claimed in claim 22, wherein the first heel tread part coupling means is an elongate tongue extending from an edge of the heel tread part and the second heel treadpart coupling means is an elongate groove defined in the portion of the midsole which provides the heel, the elongate groove being configured to receive the elongate tongue to couple the heel tread part to the midsole.

24. The foot covering as claimed in any one of claims 21 to 23, including a toe tread part coupling arrangement provided by a first toe tread part coupling means located on the toe tread part and a second toe tread part coupling means located on the midsole, the first and second toe tread part coupling means being configured to cooperate to couple the toe tread part to the midsole across a width of the midsole.

25. The foot covering as claimed in claim 24, wherein the first toe tread part coupling means is provided by two elongate members extending from an edge of the toe tread part, and the second toe tread part coupling means is provided by two elongate cavities defined in the portion of the midsole which provides the heel, each of the elongate cavities being configured to receive a cooperating elongate member to couple the toe tread part to the midsole.

26. The foot covering as claimed in any one of claims 21 to 25, including a retaining arrangement configured to retain the toe tread part on the midsole, the retaining arrangement being provided by a first retaining formation located on a first major surface of the toe tread part and a second retaining formation provided on a surface of the midsole between the first set of heel mating formations and the first set of toe mating formations.

27. The foot covering as claimed in any one of claims 1 to 26, wherein the first and second sets of mating formations are formed of thermoplastic rubber, wherein the protrusions are formed of thermoplastic rubber having a Shore of between 70 and 90; wherein the protrusions are formed of thermoplastic rubber having a Shore of between 75 and 85; wherein the protrusions are formed of thermoplastic rubber having a Shore of between 78 and 82.

28. The foot covering as claimed in any one of claims 1 to 27, wherein the first set of mating formations are integrally formed with the midsole and the second set of mating formations are integrally formed with the tread part.

29. A method of assembling a foot covering, comprising: providing an upper component and a midsole attachable to the upper component to define a foot-receiving zone in use, the midsole having a first set of mating formations defined on a first major surface thereof; providing a tread part removably attachable to the midsole by way of a second set of mating formations defined on a first major surface of the tread part, the second set of mating formations being configured tocooperate with the first set of mating formations to attach the midsole to the tread part by way of a form-fit connection; bringing into contact the first set of mating formations of the midsole with the second set of mating formations of the tread part; and, pressing together the midsole and the tread part to cause engagement of the first and second sets of mating formations to removably attach the tread part to the midsole.

30. The method of claim 29, wherein the step of pressing together the midsole and the tread part to cause engagement of the first and second sets of mating formations generates a form-fit connection to removably attach the tread part to the midsole.

31. A tread part for a foot covering, comprising: a first major surface having a second set of mating formations defined thereon, the second set of mating formations being configured to cooperate with a first set of mating formations defined in a midsole to removably attach the tread part to the midsole.