OPEN ORTHOPEDIC SHOE AND METHOD FOR MANUFACTURING AN OPEN ORTHOPEDIC SHOE

Abstract

Open orthopedic shoe (1) comprising: a sole (10); a strap (20) for holding the shoe at the back of the foot and / or a fastener (30) for holding the shoe at the front of the foot. According to the invention, said sole (10) comprises an upper layer (11) for contact with the foot and which covers a support part (12) intended to rest on the ground, where the upper layer (11) is made so as to provide the necessary orthopedic correction and the support part (12) and comprises at least two zones (121, 122, 123, 124, 125) having different hardnesses, the average thickness of the support part (12) being greater than that of the upper layer (11) of the sole (10). Figure for abstract: Fig. 1b

Description

Title of the invention: OPEN ORTHOPEDIC SHOE AND METHOD FOR MANUFACTURING AN OPEN ORTHOPEDIC SHOE

[0001] The present invention relates to the field of orthopedic shoes and more particularly concerns an open shoe made in such a way as to be able to provide the necessary orthopedic correction to the person wearing it.

[0002] In this field, closed shoes are known that include an orthopedic insole added to the shoe. An orthopedic insole is understood to mean a medical device or orthosis custom-made by a podiatrist or a podiatrist whose role is to correct the support of the foot in order to relieve pain caused when walking, mainly by deformations of the foot or by poor distribution of support. Such an orthopedic insole makes it possible to reduce pain when walking, to correct body posture, to ensure walking comfort, or even to reinforce the cushioning provided by the shoe. Orthopedic insoles are generally not bulky and easily fit into a pair of closed shoes, such as pumps, loafers, sports shoes, etc.

[0003] Generally, there is only one pair of orthopedic insoles made by a podiatrist, a pair that one wishes to use also in an open shoe. An open shoe is a shoe that allows the upper part of the foot to have an area in the open air. Such open shoes are flip-flops, clogs, slides, sandals, slippers. An open shoe generally includes a sole and fasteners or straps allowing it to be held on the foot. However, unlike a closed shoe, it is difficult to introduce an orthopedic insole into an open shoe in such a way as to keep it in place during use.

[0004] A solution to this problem has been described in document FR 3095741 which relates to an open shoe provided with lateral reinforcements in the heel area of the foot. According to this document, the shoe comprises an upper sole which has a depression allowing a comfort or anatomical sole to be received, a sole which is also held at the back of the foot by the lateral reinforcements of the shoe. However, in the case of a flip-flop, the comfort sole must be cut in order to be able to pass the flip-flop fastener. However, such a cut in the sole constitutes an area of fragility and the onset of rupture. In addition, the gaps resulting from the cut are conducive to the accumulation of dirt or moisture. Dirt or moisture can infiltrate these gaps but also at the assembly level formed by the different soles and constitute sources of deterioration of the sole. Furthermore, the need to introduce a comfort or orthopedic insole in any type of open shoe, without lateral reinforcements, is always present.

[0005] Document WO 2019 / 017974 discloses a method for manufacturing orthopedic insoles or orthoses by molding. The method uses a system for designing an orthopedic insole using computerized design software adapted to adjust the digitized information in a 3D model of the orthosis from the image of the user's foot. The system comprises an image recognition module to identify the different anatomical parts of the foot to allow the design of the orthosis, as well as a display which makes it possible to show the original scan of the foot in an opaque or semi-transparent manner on the screen to allow visualization of how the foot will adapt to the personalized orthosis designed by the system. In a variant, the orthosis thus made is glued to the inside of an open shoe.However, such a method only allows the manufacture of an orthosis from the image of the foot and certain data such as conditions present on the sole of the foot, the outline of the shoe which receives the sole, but without taking into account complex parameters, such as the body position or the distribution of the person's supports, parameters which enter into the logic and the process of making an orthopedic sole by a podiatrist.

[0006] An objective of the invention is to remedy the drawbacks of the aforementioned documents and to provide an original solution for producing an open orthopedic shoe which complies with the correction prescribed by a podiatrist, while being able to provide the necessary support and comfort when walking, and this with a minimum of components.

[0007] This objective is achieved by the invention which provides an open orthopedic shoe comprising: - a sole; - a strap intended to hold the shoe at the back of the foot and / or - a fastener intended to hold the shoe at the front of the foot, characterized in that said sole comprises an upper layer intended for contact with the foot and which covers a support part intended to rest on the ground, where the upper layer is made in such a way as to provide the necessary orthopedic correction and the support part comprises at least two zones having different hardnesses, the average thickness of the support part being greater than that of the upper layer of the sole.

[0008] In other words, the invention provides an open shoe whose sole is made in a single piece and includes the orthopedic correction indicated by a podiatrist. More precisely, the upper layer of the sole has a raised shape to hold account of the correction indicated by the podiatrist and the support or resistance part of the sole is made in such a way as to provide the support and the necessary comfort as prescribed by a podiatrist. The data necessary for the manufacture of such an open shoe sole can be obtained from an analysis report or instructions obtained after consultation with a podiatrist or from an orthopedic sole made by the latter.

[0009] Average thickness means the value obtained by averaging the thickness of the upper layer, respectively of the support part over their entire surface. The upper layer is generally thin enough to mainly give relief to the surface on which the foot rests, while the support part, which the upper layer covers, is thicker in order to support the weight that the person's foot applies to the sole when standing or moving, while protecting it from the roughness of the ground.

[0010] Thus, the sole thus obtained can then be equipped with a strap to hold the back of the foot and / or a fastener to hold the front of the foot or the toes, the strap and / or the fastener being fixed to the sole. This gives an open shoe with the necessary orthopedic correction which has very few components, while being resistant and comfortable. Maintaining the foot in position by the strap and / or the fastener, and preferably by the strap and the fastener, is very important, especially in the case of an open shoe, in order to be able to benefit from the necessary orthopedic correction.

[0011] The thickness of the upper layer can be between 0.5 and 5 mm.

[0012] Said at least two zones of different hardnesses of the support part may be made of the same material and include at least two different three-dimensional or 3D lattice-type structures and / or may be made of different materials.

[0013] Said sole may be made of a material included in the group consisting of: PLA (polylactic acid), TPU (thermoplastic polyurethane), nylon (PAU, PA12), alone or in combination. These materials are preferred for their ease of implementation by a polymer object additive manufacturing process.

[0014] Said support part can rest on the ground by means of an outer sole.

[0015] Said outer sole can be made of EVA (ethylene vinyl acetate), ca or an elastomeric mixture, silicone.

[0016] The shoe comprises a fastener and / or a strap which can each be detachably attached to said sole.

[0017] Said sole may comprise a through hole allowing the insertion of a fastener.

[0018] The objective of the invention is also achieved with a method of manufacturing a orthopedic shoe comprising a sole, a shoe support strap at the back of the foot and / or a shoe support fastener at the front of the foot comprising the following steps: a) perform a scan of the upper surface of an existing orthopedic sole; b) enter the hardness values of the different areas of the existing orthopedic sole; c) digitize the values obtained in steps a) and b) and generate a 3D model of the orthopedic insole, and d) using the 3D model generated in step c) to manufacture a sole comprising an upper layer intended for contact with the foot and which covers a support part intended to rest on the ground, where the upper layer is made in such a way as to provide the necessary orthopedic correction and the support part comprises at least two zones having different hardnesses, the average thickness of the support part being greater than that of the upper layer of the sole.

[0019] The sole of step d) may be a polymer object obtained by an additive manufacturing process.

[0020] Said support part can rest on the ground by means of an outer sole which can be obtained by molding rubber or rubber powder, or by injecting EVA (ethylene vinyl acetate) foam, rubber or silicone.

[0021] Said strap can be made of leather, which can be traditional leather or leather of non-animal origin (known as "vegan leather"), vegetable leather or fabric by being obtained by cutting using a laser beam, using a die cutter, using a water jet or it is made by molding a polymer material.

[0022] Said attachment may be a polymer object obtained by additive manufacturing or by injection of a polymer material.

[0023] An additive manufacturing process according to the invention may be a process of the SLS type (Selective Laser Sintering in English, or selective laser sintering in French), FDM (Fused Deposition Modeling in English, or modeling by deposition of fused wire in French), SLA (Stereolithography in English, or stereolithography in French), DLP (Digital Light Processing in English, or digital treatment of light in French) or by polymer injection. The material used is chosen from the group consisting of: PLA (polylactic acid), TPU (thermoplastic polyurethane), nylon (PAU, PA 12), alone or in combination. These materials are preferred for their ease of implementation by a polymer object additive manufacturing process.

[0024] The assembly between the sole, the outer sole and the strap and / or the fastener can be done by gluing.

[0025] The invention will be better understood thanks to the rest of the description, which is based on the following figures: [Fig. 1a] is a perspective view of a pair of open shoes of the invention; [Fig.lb] is an exploded perspective view of an open shoe of [Fig.la]; [Fig.2] is a perspective view of the inner part of the sole of the open shoe according to a first embodiment of the invention; [Fig.3] is a perspective view of the outer sole of the open shoe of the invention; [Fig.4] is an exploded perspective view of a fastener and its decorative element for an open shoe of the invention; [Fig.5] illustrates a top view of a strap for an open shoe of the invention; [Fig.6] is a perspective view of a pair of soles of the open shoe sole according to a second embodiment of the invention; [Fig.7] is a bottom view of the sole of [Fig.6] and [Fig.8] an enlarged scale detail of it.

[0026] In the various figures, identical or similar elements bear the same reference. Their description is therefore not systematically repeated.

[0027] [Fig.1a] illustrates a pair of open shoes according to the invention and [Fig.1b] illustrates by an exploded view an open shoe of the invention. More particularly in an exemplary embodiment illustrated in [Fig.1b], the open shoe 1 comprises a sole 10, a strap 20 and a fastener 30 as well as an external covering or outer sole 40.

[0028] According to the invention, the sole 10 comprises an upper layer 11 intended for contact with the foot and which covers a support part 12 intended to rest on the ground, where the upper layer 11 is made so as to provide the necessary orthopedic correction and the support part 12 comprises at least two zones having different hardnesses, the average thickness of the support part 12 being greater than that of the upper layer 11 of the sole 10.

[0029] The thickness of the upper layer 11 is between 0.5 and 5 mm and is preferably between 1 and 2 mm.

[0030] One of the roles of the support part 12 is to absorb the weight of a person when they rest on the sole 10, it therefore has sufficient strength to not break or permanently deform in use. The support part 12 rests on the ground with its lower face 16, directly or via an outer sole 40. The upper face 17 of the support part 12 is covered with the upper layer 11 shaped to receive the sole of a person's foot.

[0031] Another role of the support part 12 is to ensure the support and comfort of the a person's foot depending on the position of its supports. For this reason, the support part has at least two zones with different hardnesses within its perimeter 15.

[0032] In a first embodiment of the invention, as best seen in [Fig.2], the sole 10 is made of different materials. More particularly, three zones 121', 122' and 123' are noted on the surface of the sole 10. Each zone is made of a material having a hardness different from that of the materials of the other zones. Such a sole can for example be made by an additive manufacturing process or 3D printing of a polymer object, by molding or even by injection of a polymer material. By way of example, the hardness of the zone 121' is approximately 40 Shore A, that of the zone 122' approximately 60 Shore A, that of the zone 123' approximately 20 Shore A.

[0033] In this embodiment, the upper layer 11 is made from the same materials as those of the zones 121', 122' and 123' of the support part 12.

[0034] In a second embodiment illustrated in Figures 1b, 6, 7 and 8, the zones 121, 122, 123, 124, 125, 126, 127 having different hardnesses from the support part 12, as well as the upper layer 11 of the sole 10 are made of the same material. In order to be able to vary the hardness of the different zones, these have a 3D lattice type structure (or "lattice" in English) and are made by an additive manufacturing process. Thus and as visible in the figures, this 3D lattice type structure is a structure made from open cells. An open cell is defined by its geometric shape (several square-shaped cells being illustrated in the figures), by its dimensions and by the thickness of its walls. A lattice type structure thus comprises a repetition of several cells of a predefined geometry.Several lattice-like structures may be superimposed in an area of the support portion 12.

[0035] A zone according to the present invention is delimited by continuous walls of the contour or periphery 15 of the sole 10 and by continuous walls delimiting adjacent zones. Thus, the zone 121 is delimited by the periphery 15 and by the continuous boundary wall with the adjacent zone 122. The zone 123 is delimited by the periphery 15, by the boundary wall with the zone 122 and by that with the zone 124. The other zones are delimited in a similar manner, as better seen in [Fig.7].

[0036] For example, the equivalent hardnesses of the different zones are between 5 and 100 shore A measured according to the standards ASTM D2240, ISO 868 and ISO 7619-1. We speak here of equivalent hardness because for the same material with its own hardness (e.g.: 70 shore A) we can have different lattice structures giving zones with hardnesses equivalent to or lower than the material itself. We can also have the same lattice everywhere but with materials of different shore hardnesses (e.g.: 70 and 90 shore A).

[0037] In one variant, different materials are used for at least two zones of different hardness.

[0038] The sole 10 according to this second embodiment is obtained using an additive manufacturing process.

[0039] An additive manufacturing process according to the invention may be a process of the SLS type (Selective Laser Sintering in English, or selective laser sintering in French), FDM (Fused Deposition Modeling in English, or modeling by deposition of fused wire in French), SLA (Stereolithography in English, or stereolithography in French), DLP (Digital Light Processing in English, or digital treatment of light in French) or by polymer injection.

[0040] The material used to make the sole 10 is chosen from the group consisting of: PLA (polylactic acid), TPU (thermoplastic polyurethane), nylon (PAU, PA12), alone or in combination. These materials are preferred for their tolerance to skin contact.

[0041] Additive manufacturing generally uses a 3D printer into the memory of which a 3D printing file is downloaded, generally comprising a slicing of the 3D model of the sole and printing parameters. The 3D model of the sole is obtained by scanning an existing orthopedic sole, manufactured by a podiatrist and by measuring the hardness of the different areas comprising it. The geometry of the existing sole is measured by a non-contact measuring means, such as an optical scanner, or by contact, such as a three-dimensional probing device. The measurement record also includes measurements of other characteristics such as hardness and roughness, using a durometer device, such as a portable durometer with a penetrating foot, and a portable roughness meter with a measuring probe or an optical roughness measurement.

[0042] In one variant, the 3D model of the sole is obtained by scanning an existing orthopedic sole, manufactured by a podiatrist, and manually entering digital data corresponding to the different hardnesses of the support zones. In yet another variant, the 3D model of the sole is produced using digital data transmitted by a podiatrist who has examined the person for whom the open shoe is to be manufactured. This method makes it possible to have access to the correction of an orthopedic sole without going back to the podiatrist, and to integrate it into the construction of open orthopedic shoes, such as sandals, flip-flops, slippers, clogs.

[0043] As better seen in Figures 1b and 8, the sole 10 comprises in its front part a through hole 18 allowing the insertion of the fastener 30 intended to hold the shoe at the toes. The hole 18 is made within a cylindrical cavity 19, for reinforcement, located on the lower face of the sole 10.

[0044] A fastener assembly 30 is best seen in [Fig. 4]. It comprises a body 31 of elongated shape and oval or drop-shaped cross-section and ending in a flattened upper part 34 which serves as a support for a pellet 32 removably mounted on its support. The lower part of the body 31 is held by a base 33 in the cylindrical cavity 19 of the sole 10.

[0045] In a variant, the fastener which serves to hold the shoe at the front of the foot may be a strap of the type used in the manufacture of sandals or mules.

[0046] In the example illustrated in the figures, the open shoe also comprises a strap assembly 20 which ensures that the shoe is also held in place in the rear part of the foot. [Fig.5] illustrates such a strap in plan view and comprising: a central part 21 provided with a through hole 23 at the front, the central part extending towards the rear by two lateral parts 22.

[0047] The strap is fixed to the sole 10 by fixing the central part 21 to the fastener 30 and the lateral parts on the periphery of the sole 10.

[0048] In the example illustrated in Figures 1a and 1b, the lateral parts of the strap 20 join and are fixed using their joining part to the rear of the sole for better support of the rear of the foot. With reference to [Fig.lb], the strap 20 comprises an orifice 24 which cooperates with a stud 35 located on the upper part of the fastener 30 allowing the two parts to be better positioned relative to each other and to prevent rotation of the fastener.

[0049] An outer sole 40 provided with raised parts 41 ([Fig.3]) ensuring better grip of the sole completes the assembly formed by the sole 10, the strap 20 and the fastener 30. In a preferred embodiment, the assembly of these components is carried out by gluing.

[0050] In another embodiment, the fastener 30 and / or the strap 20 are detachably mounted on the sole 10, for example using press studs or any other removable assembly means known to those skilled in the art.

[0051] Other variations and embodiments of the invention may be envisaged within the scope of the invention as claimed.

[0052] Thus, the 3D model of the sole can be used to make a mold and obtain the sole by molding or injecting a polymer material using this mold.

Claims

Claims

1. Open orthopedic shoe (1) comprising: - a sole (10); - a strap (20) intended to hold the shoe at the back of the foot and / or - a fastener (30) intended to hold the shoe at the front of the foot, characterized in that said sole (10) comprises an upper layer (11) intended for contact with the foot and which covers a support part (12) intended to rest on the ground, where the upper layer (11) is made so as to provide the necessary orthopedic correction and the support part (12) comprises at least two zones (121, 122, 123, 124, 125, 126, 127, 121', 122', 123') having different hardnesses, said at least two zones are made of the same material and comprise at least two different 3D lattice-type structures, the average thickness of the support part (12) being greater than that of the upper layer (11) of the sole (10).

2. Shoe according to claim 1 characterized in that the thickness of the upper layer (11) is between 0.5 and 5 mm.

3. Shoe according to one of the preceding claims, characterized in that said sole (10) is made of a material included in the group formed of: PLA (polylactic acid), TPU (thermoplastic polyurethane), nylon (PAU, PA 12), alone or in combination.

4. Shoe according to one of the preceding claims, characterized in that said support part (12) rests on the ground by means of an outer sole (40).

5. Shoe according to the preceding claim, characterized in that said outer sole (40) is made of EVA (Ethylene vinyl acetate) or rubber or silicone.

6. Shoe according to one of the preceding claims, characterized in that at least one of the fastener (30) and the strap (20) is detachably fixed to said sole (10).

7. Shoe according to one of the preceding claims, characterized in that the sole (10) comprises a through hole allowing the insertion of the fastener (30).

8. Method for manufacturing an open orthopedic shoe (1) comprising a sole (10), a strap (20) for holding the shoe at the back of the foot and / or a fastener (30) for holding the shoe at the front of the foot comprising the following steps: a. performing a scan of the upper face of an existing orthopedic sole; b. entering the hardness values of the different zones of said existing orthopedic sole; c. digitizing the values obtained in steps a) and b) and generating a 3D model of the orthopedic sole, and d.using the 3D model generated in step c) to manufacture a sole (10) comprising an upper layer (11) intended for contact with the foot and which covers a support part (12) intended to rest on the ground, where the upper layer (11) is made so as to provide the necessary orthopedic correction and the support part (12) comprises at least two zones (121, 122, 123, 124, 125, 126, 127, 121', 122', 123') having different hardnesses, said at least two zones are made of the same material and comprise at least two different 3D lattice-type structures, the average thickness of the support part (12) being greater than that of the upper layer (11) of the sole (10).

9. Method according to the preceding claim, characterized in that the sole (10) of step d) is a polymer object obtained by an additive manufacturing process.

10. Method according to one of claims 8 or 9, characterized in that said support part (12) rests on the ground by means of an outer sole (40) obtained by molding rubber or gum powder, or by injection of EVA (ethylene vinyl acetate) foam, rubber or silicone.

11. Method according to one of claims 8 to 10, characterized in that said strap (20) is made of vegan leather, vegetable leather or fabric, being obtained by cutting using a laser beam, using a die cutter, using a water jet or it is made by molding a polymer material.

12. Method according to one of claims 8 to 11, characterized in that said fastener (30) is a polymer object obtained by additive manufacturing or by injection of a polymer material.

13. Method according to one of claims 10 to 12, characterized in that the assembly between the sole (10), the outer sole (40) and the strap (20) and / or the fastener (30) is done by gluing.

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