A magnet incorporated sole assembly and footwear thereof

Abstract

A magnet incorporated sole assembly (100) and footwear (200) thereof is disclosed in the present invention. The sole assembly (100) includes a midsole region having at least one magnet chamber (140) housing a first magnet (150) and a second magnet (160) arranged with like poles facing each other across a pre-determined gap (170). Upon application of vertical load during walking or running, the gap reduces and generates a repulsive magnetic force that resists compression of the sole assembly (100). The repulsive force exhibits a non- linear force–displacement response, thereby providing adaptive cushioning and energy return. The magnets are configured to remain non-contacting under normal operational loads, reducing mechanical wear and material fatigue. The invention provides improved shock absorption, progressive load resistance, enhanced durability, and sustained rebound performance compared to conventional foam-based cushioning systems.

Description

PCT-IN26-LYAPL001A MAGNET INCORPORATED SOLE ASSEMBLY AND FOOTWEAR THEREOF CROSS REFERENCE TO RELATED APPLICATION

[0001] The present application claims priority from the Provisional Application No. IN202541021130 filed on March 08, 2025, the full disclosure of which is hereby incorporated by reference herein.FIELD OF THE INVENTION

[0002] The present invention relates generally to footwear and sole assemblies. More particularly, the invention relates to a footwear system incorporating a magnet-based repulsive cushioning mechanism within a sole assembly. The invention concerns a noncontact magnetic elastic support system integrated within the midsole region of footwear to provide adaptive cushioning, impact attenuation, and energy return during walking, running, standing, and multi -directional movements.BACKGROUND OF THE INVENTION

[0003] The sedentary nature of modern lifestyles affords limited opportunities for physical activity, including walking. Consequently, the global prevalence of lifestyle diseases, such as diabetes and obesity, continues to escalate annually, posing significant health concerns worldwide. As a result, people are embracing a healthier lifestyle, characterized by regular physical activity, such as taking over 6,000 steps, playing sports like table tennis, badminton, box cricket at office and incorporating movement into their daily routines even if they work from home.

[0004] Footwear designed for daily use, sports, and prolonged standing commonly incorporates cushioning systems within the sole assembly to attenuate impact forces and improve user comfort. Conventional cushioning structures primarily rely on polymeric foamPCT-IN26-LYAPL001materials such as ethylene-vinyl acetate (EVA), thermoplastic polyurethane (TPU), expanded TPU, and related elastomeric compounds. These materials provide initial resilience; however, over repeated loading cycles, they are susceptible to compression set, material fatigue, and gradual loss of rebound characteristics.

[0005] In an effort to improve energy return and shock absorption, various mechanical spring systems and air-filled or gel-based inserts have been introduced into footwear. While such systems may enhance rebound performance, they often introduce structural complexity, localized stress concentration, mechanical wear, and potential long-term failure due to repeated mechanical contact. Contact-based elastic elements may degrade over time, leading to inconsistent cushioning performance.

[0006] Additionally, conventional foam-based midsoles typically exhibit either relatively linear stiffness behavior or performance degradation after repeated compression. They may provide insufficient adaptive resistance under higher loads or excessive softness under dynamic movements, resulting in reduced stability and suboptimal energy return.

[0007] There remains a need for an alternative cushioning mechanism that provides progressive, adaptive stiffness while minimizing material fatigue and mechanical wear. Such a system should deliver improved energy return, consistent performance over extended usage cycles, and tunability for different user weights and activity levels without introducing complex mechanical components.

[0008] The present invention satisfies this need, as well as others, and generally overcomes the deficiencies found in the background art.PCT-IN26-LYAPL001OBJECT OF THE INVENTION

[0009] It is an object of the present invention to provide a footwear incorporating a magnetbased repulsive cushioning mechanism within a sole assembly.

[0010] It is another object of the invention to provide a non-contact elastic support mechanism that reduces reliance on conventional foam compression or mechanical spring elements.

[0011] It is a further object of the invention to provide adaptive cushioning characterized by a non-linear force-displacement response, wherein resistance progressively increases as compressive load increases.

[0012] It is yet another object of the invention to provide improved durability by minimizing mechanical wear and compression set associated with traditional cushioning materials.

[0013] These and other objects of the invention will become apparent from the detailed description that follows.SUMMARY OF THE INVENTION

[0014] In a broad aspect, the present invention provides footwear comprising an upper and a sole assembly secured thereto, wherein the sole assembly may comprise a single unitary sole structure or may comprise multiple sole regions including an upper sole, a midsole, and a lower sole. In embodiments where the sole assembly comprises multiple sole regions, at least one magnet chamber disposed between any two adjacent sole regions comprises at least one magnet chamber housing at least two permanent or normal magnets arranged with like poles facing each other across a pre-determined gap. In embodiments where the sole assembly comprises a single unitary sole structure, the sole assembly itself comprises at leastPCT-IN26-LYAPL001one magnet chamber housing at least two permanent or normal magnets arranged with like poles facing each other across a pre-determined gap.

[0015] In another aspect, the invention provides a sole assembly configured to be incorporated into footwear, the sole assembly comprising a forefoot portion, a midfoot portion, and a heel portion, and including at least one magnet chamber formed within a midsole region, wherein the magnet chamber houses a first magnet and a second magnet arranged such that like poles face each other across a pre-determined gap under no-load condition.

[0016] In operation, application of vertical load during walking, running, or standing reduces the pre-determined gap between the magnets, thereby generating a repulsive magnetic force that resists compression of the sole assembly. The repulsive force provides a non-contact elastic support mechanism and exhibits a non-linear force-displacement profile, delivering adaptive cushioning and energy return.

[0017] Because the repulsive force is generated without physical contact between the magnets under normal walking loads, the present invention minimizes mechanical wear and reduces long-term performance degradation associated with contact-based springs and repeated foam compression.

[0018] In certain aspects, the magnet chambers are formed within compression-moulded EVA, TPU, expanded TPU, or similar materials that constrain lateral movement of the magnets, maintain alignment of magnetic poles, and prevent tearing of the sole due to magnetic forces.

[0019] The invention further provides embodiments wherein magnet grade, geometry, number, orientation, and chamber configuration may be adjusted to tune the cushioning response for different applications and user requirements.PCT-IN26-LYAPL001BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Having thus described the subject matter of the present invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and whereinFigure 1 illustrates a cross-section view of the magnet incorporated sole assembly;Figure 2 shows a schematic view of the footwear with magnet incorporated sole assembly;Figure 3 shows a cross-section view of the magnet incorporated sole assembly;Figure 4 shows an illustrative view of the magnet incorporated sole assembly;Figure 5 shows an illustrative schematic view of the footwear with magnet incorporated sole assembly;Figure 6 shows an illustrative schematic view of the removable midsole insert;Figure 7 shows an illustrative schematic view of the magnet incorporated sole assembly in compressed condition; andFigure 8a and 8b is a schematic graph showing displacement-force and stiffness-force characteristics of magnetic nonlinear spring compared to a conventional linear spring.

[0021] Skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have necessarily been drawn to scale. Further, the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.PCT-IN26-LYAPL001DESCRIPTION OF THE INVENTION

[0022] The subject matter of the present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of subject matter of the present invention are shown. The subject matter of the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Indeed, many modifications and other embodiments of the subject matter of the present invention set forth herein will come to mind to one skilled in the art to which the subject matter of the present invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. All illustrations of the drawings are for the purpose of describing selected versions of the present invention and are not intended to limit the scope of the present invention. Therefore, it is to be understood that the subject matter of the present invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims.

[0023] As a preliminary matter, it will readily be understood by one having ordinary skill in the relevant art that the present disclosure has broad utility and application. As should be understood, any embodiment may incorporate only one or a plurality of the above-disclosed aspects of the disclosure and may further incorporate only one or a plurality of the abovedisclosed features. Furthermore, any embodiment discussed and identified as being “preferred” is considered to be part of a best mode contemplated for carrying out the embodiments of the present disclosure. Other embodiments also may be discussed for additional illustrative purposes in providing a full and enabling disclosure. Moreover, many embodiments, such as adaptations, variations, modifications, and equivalent arrangements,PCT-IN26-LYAPL001will be implicitly disclosed by the embodiments described herein and fall within the scope of the present disclosure.

[0024] Furthermore, it is important to note that, as used herein, “a” and “an” each generally denotes “at least one”, but does not exclude a plurality unless the contextual use dictates otherwise. When used herein to join a list of items, “or” denotes “at least one of the items”, but does not exclude a plurality of items of the list. Finally, when used herein to join a list of items, “and” denotes “all of the items of the list”.

[0025] For the better understanding of the objects, technology and advantages of the present invention, the instant invention will be further explained in detail with respect to embodiments and accompanying figures as given above. It should be understood that the specific embodiments described herein are only to be used for explaining the present invention but not used to limit the present invention.

[0026] The present invention relates to footwear and sole assembly / assemblies incorporating a magnetic repulsion mechanism configured to provide adaptive cushioning, impact attenuation, and energy return during walking, running, standing, and multidirectional movement activities. More particularly, the invention relates to a footwear comprising a magnet-incorporated sole assembly configured such that like poles of at least two permanent or normal magnets are oriented facing each other across a pre-determined gap, thereby generating a controlled repulsive force that functions as a non-linear elastic support element.

[0027] In an embodiment, the invention provides footwear comprising an upper and a sole assembly secured thereto, wherein the sole assembly may comprise a single unitary sole structure or may comprise multiple sole regions including an upper sole, a midsole, and a lower sole. In embodiments where the sole assembly comprises multiple sole regions, at leastPCT-IN26-LYAPL001one of the sole regions comprises at least one magnet chamber housing at least two permanent or normal magnets arranged with like poles facing each other across a predetermined gap. In embodiments where the sole assembly comprises a single unitary sole structure, the sole assembly itself comprises at least one magnet chamber housing at least two permanent or normal magnets arranged with like poles facing each other across a predetermined gap. The repulsive force generated between the magnets resists compressive loads applied during gait, thereby providing dynamic cushioning and energy return.

[0028] In another embodiment, the invention provides a sole assembly configured to be incorporated into footwear, the sole assembly comprising a forefoot portion, a midfoot portion, and a heel portion, wherein at least one of said portions comprises a magnet chamber containing a pair of magnets arranged with like poles facing each other across a predetermined gap, thereby generating a repulsive magnetic force when subjected to vertical loading.

[0029] In yet another embodiment, the invention provides a method of providing adaptive cushioning and energy return in footwear, comprising arranging at least two magnets within a sole assembly such that like poles face each other across a pre-determined gap, positioning the sole assembly within footwear, permitting controlled compression of the gap during walking or running such that magnetic repulsion resists impact forces, and allowing restoration of the sole assembly toward its original configuration upon load release.

[0030] In preferred embodiments, the magnet-incorporated sole assembly is positioned within the midsole region of the footwear, as the midsole primarily governs impact attenuation and ride characteristics.

[0031] The magnet-incorporated sole assembly may be positioned near the heel portion. The magnet chamber may alternatively or additionally be provided in the forefoot portion, aPCT-IN26-LYAPL001midfoot portion, or distributed across multiple regions depending on load distribution and performance requirements.

[0032] In a particularly preferred embodiment, the magnet chamber is located within the midsole portion beneath the heel region, as heel strike typically experiences the highest ground reaction forces. In this configuration, the magnets act as a non-contact spring system, eliminating material fatigue typically associated with mechanical coil springs or foam compression breakdown.

[0033] The magnets may be cylindrical disc-type, rectangular block-type, ring-shaped, spherical, polygonal, or any other geometrical configuration suitable for integration into a footwear sole. In certain embodiments, cylindrical disc magnets are preferred due to uniform axial force distribution. In alternative embodiments, rectangular or custom-profile magnets may be employed for space optimization within thin sole constructions.

[0034] Multiple magnet pairs may be arranged in parallel or series configurations across the heel, midfoot, or forefoot regions to tailor stiffness characteristics according to user weight, activity type, or footwear category.

[0035] A method of manufacturing a footwear having a magnet-based cushioning system, the method comprising: forming a midsole body from a polymeric material; creating at least one magnet chamber within the midsole body; positioning a first magnet and a second magnet within the magnet chamber such that like poles face each other across a predetermined gap under no-load condition; securing the magnets within the magnet chamber in axial alignment to permit controlled reduction of the gap under vertical load; and assembling the midsole body with an upper and an outsole to form the footwear, wherein the magnets are configured to generate a repulsive magnetic force upon reduction of the gap to provide non-contact cushioning.PCT-IN26-LYAPL001

[0036] In an embodiment, the magnet chamber is formed during compression moulding of the midsole body.

[0037] In an embodiment, the magnet chamber is formed by machining, cutting, or postmould cavity formation.

[0038] In an embodiment, the magnets are neodymium iron boron magnets.

[0039] In an embodiment, the method further comprising selecting magnet diameter, thickness, and magnetic grade to achieve a predetermined repulsion strength under axial loading.

[0040] In an embodiment, the method further comprising providing an initial air gap between the magnets such that the magnets remain non-contacting under normal walking loads.

[0041] In an embodiment, the method further comprising encapsulating the magnets within a containment structure to prevent lateral displacement.

[0042] In an embodiment, the magnet chamber is positioned in at least one of a heel region, midfoot region, or forefoot region of the midsole body.

[0043] The method further comprising testing the assembled magnet pair under incremental loading to verify repulsion strength prior to integration into the footwear

[0044] Referring to the accompanying drawings, the present invention illustrates a magnetincorporated sole assembly generally denoted by reference numeral (100) and footwear incorporating the same generally denoted by reference numeral (200).

[0045] In one embodiment, as shown in Figure 1, the sole assembly (100) comprises a forefoot portion (110), a midfoot portion (120), and a heel portion (130). The sole assemblyPCT-IN26-LYAPL001(100) may be structured as a single integral unit or as a layered construction comprising an insole layer, a midsole layer, and an outsole layer.

[0046] Figure 2 illustrates footwear (200) comprising an upper (210) and the sole assembly (100) secured thereto. The upper (210) may be formed from leather, synthetic materials, fabric, mesh, polymeric sheets, or combinations thereof. The sole assembly (100) is attached to the upper (210) through conventional bonding, stitching, moulding, or fusion techniques.

[0047] Again, referring to figure 2, at least one magnet chamber (140) is formed within the sole assembly (100). In a preferred embodiment, the magnet chamber (140) is located within the heel portion (130), although alternative placements within the forefoot portion (110) or midfoot portion (120) are also contemplated.

[0048] Figure 3 illustrates a sectional view of the sole assembly (100) showing the magnet chamber (140) positioned within the midsole region. The magnet chamber (140) houses a first magnet (150) and a second magnet (160), arranged such that like poles face each other across a pre-determined gap (170) under no-load condition.

[0049] In the illustrated embodiment, the first magnet (150) is positioned toward the upper side of the magnet chamber (140) and the second magnet (160) is positioned toward the lower side. The magnets are aligned substantially along a vertical axis such that compressive forces applied during walking reduce the pre-determined gap (170), thereby generating an increasing magnetic repulsive force.

[0050] Figure 4 illustrates an embodiment wherein multiple magnet chambers (140a, 140b) are distributed across the heel portion (130) and forefoot portion (110) to provide distributed cushioning and load balancing.PCT-IN26-LYAPL001

[0051] Figure 5 illustrates a cross-sectional view footwear (200) with the sole assembly (100), depicting the magnet chamber (140) embedded within the midsole structure. The chamber walls (141) are formed from compression-moulded material to restrict lateral movement of the magnets while permitting controlled axial displacement.

[0052] In certain embodiments, guide members, sleeves, or stabilizing ribs may be provided within the magnet chamber (140) to maintain alignment of the first magnet (150) and second magnet (160) during repeated compression cycles.

[0053] Figure 6 illustrates an alternative embodiment wherein the magnet chamber (140) is integrated within a removable midsole insert (180), which can be positioned within the footwear (200) and optionally replaced to alter stiffness characteristics.

[0054] Figure 7 illustrates an embodiment in which a protective separator or non-magnetic buffer layer (190) is positioned adjacent to one or both magnet chambers to prevent physical contact under extreme loading conditions while maintaining repulsive functionality. The buffer layer may air, foam, elastomeric material, or a combination thereof.

[0055] Figure 7 also illustrates the sole assembly (100) in compressed condition during heel strike, wherein the pre-determined gap (170) is reduced relative to its rest configuration, thereby increasing the magnetic repulsive force resisting further compression.

[0056] Figure 8a and 8b schematically illustrates a conceptual displacement-force and stiffness-force profile comparing a conventional linear spring with the magnet -based spring system of the present invention.

[0057] In a conventional linear spring system, force increases proportionally with displacement, resulting in a substantially constant stiffness throughout compression. SuchPCT-IN26-LYAPL001behavior may produce relatively larger changes in deceleration during heel strike, particularly when subjected to higher loads.

[0058] In contrast, the magnet pair arranged with like poles facing each other produces a non-linear force-displacement response. As the magnets approach each other, the repulsive force increases disproportionately relative to reduction in gap distance. This results in an initially lower effective stiffness during early compression, followed by progressively higher stiffness as the magnets move closer together.

[0059] This progressive stiffness characteristic permits relatively higher compression velocity during initial part of the foot gait, thereby improving damping characteristics and distributing impact over time. As compression continues, increasing magnetic resistance reduces further acceleration and mitigates already reduced peak deceleration forces.

[0060] The resulting behavior provides controlled deceleration during heel strike and assists energy return during lift-off. The magnetic nonlinear spring thus functions as a load-responsive damping and thrust-assist mechanism integrated within the sole assembly.

[0061] The observed displacement-force behavior from figure 8 demonstrates that the magnet-based cushioning system provides progressive load resistance rather than constant stiffness. This enables reduction of peak impact forces while maintaining responsive energy return. The non-contact magnetic interaction produces repeatable nonlinear stiffness characteristics without reliance on material compression or mechanical spring deformation. Accordingly, the system contributes to reduced joint impact, smoother gait transition, and reduced perceived effort during walking or running accompanied with relatively higher upward trust.

[0062] The present invention provides a magnet-based cushioning system that generates a non-linear force-displacement response within the sole assembly of footwear. UnlikePCT-IN26-LYAPL001conventional foam-based systems that exhibit approximately linear compression characteristics within their operating range, the magnet pair arranged with like poles facing each other produces a progressively increasing repulsive force as the gap between the magnets decreases.

[0063] This non-linear behavior results in relatively lower effective stiffness during the initial phase of compression, followed by progressively higher stiffness as loading increases (later phase of compression). During heel strike or initial foot contact, the lower initial stiffness permits controlled compression and improved damping characteristics, thereby distributing impact forces over time. As compression continues and the magnets approach each other, the increasing repulsive force provides higher resistance, reducing peak deceleration and limiting excessive collapse of the sole assembly.

[0064] Even in embodiments where the magnets may contact at maximum loading, the magnetic repulsive force remains continuously present throughout the compression cycle and contributes to load sharing prior to surface contact. The magnetic system thus functions as a progressive load-responsive element that modifies the velocity and deceleration profile during gait.

[0065] Upon unloading during gait transition and lift-off, the stored magnetic potential energy assists in restoring the original gap between the magnets, thereby contributing to an upward thrust and energy return. This results in reduced perceived effort during walking or running.

[0066] Accordingly, the invention provides the technical effects of controlled nonlinear stiffness, reduction of peak impact forces transmitted to lower limb joints, enhanced energy return, improved durability due to reduced reliance on material compression, and sustained cushioning performance over repeated load cycles.PCT-IN26-LYAPL001

[0067] It is to be understood that the sole assembly (100) may be incorporated into various types of footwear (200) including but not limited to formal shoes, sports shoes, casual shoes, sandals, hiking boots, slippers, and other footwear categories. The structural dimensions, thickness, and material composition of the sole assembly (100) may vary depending upon the intended application without departing from the scope of the invention.

[0068] The upper (210) can be constructed from knit, mesh, leather, synthetic leather, or other materials suitable for all-day use. Reinforcement may be provided in the heel, midfoot, and toe regions to support containment during lateral and multi-directional movements encountered in gym activities and light sports. The upper may be designed with office-appropriate aesthetics while maintaining performance functionality, enabling users to transition between work and physical activity without changing footwear. An insole may be removable or integrated and may be contoured to provide arch support and pressure distribution, cooperating with the magnetic midsole to reduce localized pressure points.

[0069] The outsole may be formed from rubber, TPU, or other abrasion-resistant materials and is bonded to the midsole region. The outsole may include tread patterns optimized for office floors, indoor courts, urban environments, or other use conditions. Stack height, rocker geometry, and outsole design may be adjusted to address specific user requirements.

[0070] The magnet chamber (140) is formed from compression-moulded EVA, TPU, expanded TPU, or similar materials. Chamber walls (141) constrain lateral movement of the magnets, prevent tearing of the sole due to magnetic forces, and maintain intended alignment of magnetic poles during repeated loading cycles. The magnets are encapsulated within compression-moulded or otherwise formed EVA, TPU, or similar materials to form sealed chambers that structurally integrate the magnets into the midsole.PCT-IN26-LYAPL001

[0071] Guide members, sleeves, stabilizing ribs, or structural reinforcements may be provided to ensure axial alignment and prevent excessive lateral displacement.

[0072] The midsole region may further comprise conventional foam, gel, or other cushioning materials surrounding the magnet chambers to provide additional damping and comfort. The midsole may be formed from one or more cushioning materials such as EVA, TPU, expanded TPU, or blends thereof, optionally arranged in multiple layers of different densities to achieve desired ride characteristics.

[0073] The permanent or normal magnets may be cylindrical disc-type, rectangular blocks, ring-shaped elements, spherical forms, polygonal shapes, or customized geometries suitable for integration within the sole assembly. Cylindrical disc magnets may be preferred in certain embodiments due to uniform axial force distribution; however, alternative geometries may be selected for space optimization.

[0074] The magnets may comprise rare-earth magnets, such as neodymium magnets, any rare earth magnet like samarium-cobalt, neodymium-iron-boron magnets, or any other magnet having selected grade, energy product, dimensions, and geometry to generate the desired repulsive force profile. The magnitude of repulsive force may be adjusted by altering magnet grade, dimensions, number of magnets per chamber, chamber geometry, and compliance of surrounding materials.

[0075] In certain embodiments, the magnets are arranged along a vertical axis. In alternative embodiments, the magnets may be arranged in combinations of vertical, oblique, and horizontal orientations to tailor the force profile during multi -directional movements.

[0076] Variants include magnet assemblies configured in Halbach arrays, wherein magnet orientations are varied sequentially to focus the magnetic field in a preferred direction, thereby increasing effective repulsive force for a given material usage. Different chamberPCT-IN26-LYAPL001numbers and placements, including additional chambers under the midfoot, medial and lateral columns, or segmented pods, may be employed for localized tuning.

[0077] In a specific embodiment, the pre-determined gap between the magnets may be approximately 9 mm under no-load condition. Upon application of load, the gap reduces progressively, generating a repulsive force that may range from approximately 05 kg to 35 kg depending upon magnet grade, size, surface area, flux density, and separation distance.

[0078] In certain embodiments, a repulsive force in the range of 15 kg to 25 kg may be generated during typical walking loads, whereas forces in the range of 15 kg to 35 kg or greater may be generated during running or jumping activities. These values are illustrative and may be varied by selecting appropriate magnet parameters and chamber compliance.

[0079] In certain non-limiting embodiments, the magnet is NdFeB N52 / N35.

[0080] In one non-limiting embodiment, the footwear comprises an upper secured to a sole assembly including an outsole, a midsole region, and optionally an insole. The midsole region includes at least one magnet chamber formed within a polymeric body. The magnet chamber houses a first permanent magnet and a second permanent magnet arranged such that like poles face each other across a pre-determined air gap under no-load condition. The magnets are axially aligned to generate a substantially vertical repulsive force when the gap is reduced during loading.

[0081] In a specific embodiment, the magnets are neodymium iron boron magnets selected from grades including N35 and N52, although other grades may be used. The magnets may be cylindrical disc-type magnets having diameters in the range of 25 mm to 50 mm and thicknesses in the range of 3 mm to 6 mm. In certain embodiments, magnet dimensions are selected to achieve a repulsion strength in the range of approximately 5 kg to 35 kg under axial loading prior to surface contact.PCT-IN26-LYAPL001

[0082] In alternative embodiments, the magnets may be rectangular blocks, square plates, ring-shaped magnets, polygonal shapes, or combinations thereof. Multiple magnet pairs may be positioned in the heel region, midfoot region, forefoot region, or distributed across multiple regions of the midsole.

[0083] In certain embodiments, the magnet chamber is formed within a compression-moulded EVA or TPU midsole body. The chamber may include internal containment walls configured to restrict lateral displacement and maintain pole alignment during repeated load cycles. The magnets are configured to remain non-contacting under normal walking loads, thereby minimizing mechanical wear.

[0084] In one embodiment of operation, the footwear incorporating the magnet chamber is worn by a user during walking, running, standing, or other locomotion activities. During heel strike or load application, vertical force applied to the sole assembly reduces the predetermined air gap between the first and second magnets.

[0085] As the gap decreases, a progressively increasing repulsive magnetic force is generated due to the like-pole orientation of the magnets. The repulsive force resists further compression of the sole assembly, thereby absorbing impact energy.

[0086] Upon reduction of the applied load during gait transition or toe-off, the repulsive magnetic force assists in restoring the initial gap between the magnets. This restoring action provides energy return and contributes to upward thrust during lift-off.

[0087] In certain embodiments, the force-displacement behavior of the magnet pair exhibits a non-linear response, such that resistance increases disproportionately as the gap narrows. This progressive stiffness provides adaptive cushioning under varying load conditions.PCT-IN26-LYAPL001

[0088] In some embodiments, the magnets are configured to generate progressive repulsive force during reduction of the gap, optionally contacting at peak load.

[0089] In one non-limiting embodiment of manufacturing, a midsole body is formed from a polymeric material selected from EVA, TPU, expanded TPU, rubber, or combinations thereof. During moulding, at least one magnet chamber is formed within the midsole body. Alternatively, the magnet chamber may be formed by machining, cutting, or cavity formation after moulding.

[0090] A first magnet and a second magnet are positioned within the magnet chamber such that like poles face each other across a pre-determined air gap under no-load condition. The magnets are secured within the chamber in axial alignment to permit controlled reduction of the gap under vertical loading.

[0091] In certain embodiments, magnet grade, diameter, thickness, and initial gap distance are selected based on desired repulsion strength and footwear application. The magnet pair may be pre-tested under incremental axial loading to verify repulsion strength prior to final assembly.

[0092] Following magnet placement, the midsole body is assembled with an outsole and secured to an upper to form the completed footwear. In certain embodiments, the magnets may be encapsulated within a containment structure to prevent displacement during repeated load cycles.

[0093] In alternative embodiments, multiple magnet chambers may be integrated into different regions of the midsole during a single moulding process.

[0094] In certain embodiments, the initial air gap between the magnets may range from approximately 1 mm to 10 mm depending on intended cushioning characteristics.PCT-IN26-LYAPL001

[0095] In some embodiments, repulsion strength may be configured to fall within ranges including 5-25 kg, 15-25 kg, 15-35 kg, or greater, depending on user weight and footwear type.

[0096] In further embodiments, the magnet-based cushioning system may be incorporated into formal shoes, casual shoes, sports shoes, sneakers, sandals, flip flops, hiking boots, street shoes, slippers, or specialized orthopedic footwear.

[0097] All such embodiments are illustrative and non-limiting, and variations in magnet configuration, material selection, chamber geometry, and placement location may be implemented without departing from the scope of the invention.

[0098] Conventional footwear midsoles primarily rely on polymeric foam materials such as EVA or TPU to provide cushioning and energy return. However, such materials are susceptible to compression set, material fatigue, and gradual loss of resilience over repeated loading cycles. Mechanical spring-based inserts have been proposed to improve rebound characteristics, but such systems introduce structural complexity, localized stress concentration, wear, and potential mechanical failure over time. Accordingly, there exists a need for an alternative cushioning mechanism capable of providing adaptive stiffness, improved energy return, and enhanced durability without reliance on contact-based mechanical springs.

[0099] The present invention addresses this technical problem by providing a magnetbased cushioning system integrated within the midsole region of a sole assembly, wherein at least two permanent or normal magnets are arranged with like poles facing each other across a pre-determined gap. Upon application of vertical load during walking, running, or standing, reduction of the pre-determined gap generates a repulsive magnetic force that resists compression of the sole assembly. Because the resisting force is generated through magneticPCT-IN26-LYAPL001repulsion rather than mechanical contact, the system functions as a non-contact elastic support mechanism.

[0100] The magnetic repulsion system produces a non-linear force-displacement response, wherein initial compression is relatively compliant to provide cushioning comfort, and resistance progressively increases as the gap reduces, thereby delivering adaptive stiffness under higher loads. This progressive response enables improved impact attenuation, energy return, and load distribution when compared to conventional foam-only midsoles. The ability to tune magnet grade, geometry, chamber configuration, and gap distance further allows customization of the force profile to suit different user weights and activity levels.

[0101] Because the repulsive force is generated without physical contact between the magnets under normal walking loads, the system minimizes frictional wear and mechanical fatigue typically associated with springs or repeated polymer compression. The magnet chambers are structurally integrated within compression-moulded ethylene vinylacetate copolymer (EVA), thermoplastic polyurethane (TPU), polyethylene terephthalate, poly-tert-butyl methacrylate or mixture of these materials such as EVA and TPU or any elastomer, or similar materials to constrain lateral movement and maintain alignment, thereby preventing tearing of the sole due to magnetic forces. This non-contact configuration enhances longterm durability, reduces compression set, and maintains consistent performance over extended usage cycles.

[0102] In order to evaluate the suitability of the magnet-based cushioning mechanism for incorporation within a footwear midsole assembly, experimental testing was conducted to determine the repulsion force generated between pairs of magnets arranged with like poles facing each other. The primary objective of the testing was to quantify the repulsion strength of magnets intended for integration into the midsole region of footwear. The evaluationPCT-IN26-LYAPL001parameter considered was the maximum repulsive load sustained by a magnet pair prior to surface contact (touchdown).

[0103] All testing was conducted under ambient environmental conditions at room temperature and atmospheric pressure.

[0104] Test Apparatus: A custom-built magnet repulsion strength evaluation apparatus was developed to simulate axial loading conditions corresponding to vertical compressive forces experienced within a footwear midsole. The apparatus comprised non-magnetic shafts, linear bearings for controlled vertical motion, and custom-designed magnet holding cabinets configured to ensure substantially full surface alignment between opposing magnet faces. The apparatus further included a weight-loading platform supported by wooden pegs, a 3D-printed size adjuster to accommodate different magnet diameters, and paper strips used for verifying the presence of an air gap between opposing magnet surfaces.

[0105] A calibrated weighing scale and incremental weights of 0.1 kg, 0.2 kg, 0.5 kg, 1 kg, 2 kg, 5 kg, and 10 kg were used for controlled loading.

[0106] In the test configuration, two magnets were mounted within the custom holding cabinets such that like poles (N / N or S / S) faced each other across an initial air gap. The magnets were axially aligned to ensure substantially uniform distribution of repulsive forces across their surfaces.

[0107] Sampling Procedure: The magnets tested comprised neodymium iron boron (NdFeB) permanent magnets imported in commercial batches. Multiple sizes and grades were evaluated to determine suitability for midsole applications. The tested samples included cylindrical disc-type magnets of varying diameters and thicknesses, magnetized through thickness.PCT-IN26-LYAPL001

[0108] Testing Procedure: For each test iteration, a selected magnet pair of identical size and grade was placed within the holding cabinets such that like poles faced each other. The initial levitating air gap between the magnets under no-load condition was recorded.

[0109] Incremental weights were then added vertically onto the loading platform positioned above the upper magnet. The applied load progressively reduced the air gap between the magnets due to increasing compressive force.

[0110] The air gap was monitored using thin paper strips inserted between the opposing magnet surfaces. Free movement of the paper indicated the continued presence of an air gap, confirming non-contact repulsion. Absence of paper movement indicated complete surface touchdown.

[0111] Weights were incrementally increased until the two opposing magnet surfaces contacted each other. The total weight required to eliminate the air gap was recorded as the repulsion strength of the magnet pair under axial loading.

[0112] Result: Multiple iterations of the testing produced consistent and reproducible results. The measured magnetic flux and repulsion strength values (till touchdown) are summarized below:PCT-IN26-LYAPL001

[0113] The results demonstrate that repulsion strength increases with magnet diameter, thickness, and magnetic grade. The data further confirms that the magnetic repulsion response is non-linear with respect to decreasing air gap.

[0114] Technical Interpretation and Application in Footwear: The testing confirms that a pair of magnets arranged with like poles facing each other generates a progressively increasing repulsive force as the air gap decreases under load. This non-linear forcedisplacement characteristic differs from conventional linear foam compression behavior.

[0115] When integrated into a footwear sole assembly at selected positions such as the heel region, midfoot region, or forefoot region, the magnet pair acts as a non-contact elastic element. During heel strike or weight insertion, the compressive load reduces the magnet gap, generating repulsive force that absorbs impact energy. As the load is reduced during gait transition or toe-off, the repulsive force assists in restoring the original gap, thereby contributing to upward thrust and energy return.

[0116] Because the repulsion is generated without mechanical contact under normal operational loads, material fatigue and mechanical wear are minimized. The magnet systemPCT-IN26-LYAPL001thus functions as a durable, adaptive, non-linear cushioning element suitable for integration into a midsole assembly.

[0117] It is further contemplated that by selecting appropriate magnet diameter, thickness, grade, orientation, and initial gap distance, a desired repulsion range may be achieved, including but not limited to 5 kg to 25 kg, 15 kg to 25 kg, 15 kg to 35 kg, or higher, depending on footwear type, user body weight, and intended application.

[0118] The above experimental evaluation demonstrates that the cushioning mechanism of the present invention is not a mere use of magnets in footwear, but a deliberately engineered non-contact elastic system exhibiting a progressive, non-linear force-displacement response specifically tuned for midsole integration. The recorded data establishes that repulsion strength can be predictably controlled by selecting magnet diameter, thickness, grade, and initial air gap, thereby enabling load-bearing capacities within footwear-relevant ranges while maintaining an air gap under normal operating loads. Unlike conventional foam or mechanical spring systems that rely on material compression or physical contact and are subject to fatigue and wear, the present arrangement provides adaptive resistance without mechanical contact, resulting in improved durability, energy return, and performance consistency. The experimentally validated tunability and non-linear cushioning behavior support the presence of a technical effect and distinguishes the invention from simple or arbitrary placement of magnets within footwear structures.

[0119] In certain embodiments, the magnets may be a single magnetic unit or multiple magnets.

[0120] The spring effect of magnet incorporated sole assembly (i.e. absorbing and returning of force) will not degrade overtime like in the case of actual springs or elastomer based sole assembly.PCT-IN26-LYAPL001

[0121] In certain embodiments, the magnets may be coated with coating such as nickel plating or layers of copper and nickel plating, powder coatings or paints or fluorinated parylene conformal coating covered with a polysulfone thermoplastic overlayer to avoid corrosion of magnet, thereby increasing the life time of the magnet incorporated sole assembly.

[0122] In certain embodiments, the footwear based on present invention includes but not limited to formal shoes, casual shoes, sports shoes, sneakers, sandals, flip flops, street shoes, hiking boots, slippers, and moccasins.

[0123] In certain embodiments, the upper body of the footwear is provided for housing foot of the user.

[0124] In certain embodiments, the insole is fitted to the bottom of the upper, and the midsole is between the insole and outsole, and the outsole is fitted to the bottom of the midsole.

[0125] In certain embodiments the midsole assembly is laid between the outsole assembly and the upper body of the footwear.

[0126] In certain embodiments, the insole assembly laid on the outsole assembly or is put on the outsole assembly, for providing a cushion or comfort or convenience to wearer's foot.

[0127] In certain embodiments, outsole assembly fitted under the midsole and directly contacting with the ground.

[0128] In certain embodiments, the sole assembly has outsole, midsole and insole formed integral thereto.

[0129] In certain embodiments, the wave configuration of sole assembly depends on the type of footwear.PCT-IN26-LYAPL001

[0130] In certain embodiments, thickness of magnet incorporated sole assembly or thickness of insole / midsole / outsole assembly may vary according to the type and use of the footwear.

[0131] In certain embodiments, the repulsive force and / or attraction force generated by magnet incorporated sole assembly depends on one or more parameters such as placement of the magnet in the magnet incorporated sole assembly, dimension of magnets or magnet unit, distances between the magnets, dimensions of the magnet layers, dimensions of the foam layers.

[0132] Without bounding to any particular theory, magnet incorporated sole assembly according to present invention, absorbs shock during downward motion of footwear wearer and returns energy during upward motion like a nonlinear spring. Further, unlike elastomers or spring based sole assembly, the absorption and return energy efficiency won’t degrade with time.

[0133] The magnet incorporated sole assembly according to present invention, helps in reducing pain in joints and feet of the user. Further, the user of footwear with magnet incorporated sole assembly would feel lighter when they stand on the ground.

[0134] In certain embodiments, the magnetic repulsion force generated between the magnets is lower than the total body weight of the user. For example, a magnet pair may generate a repulsion force of approximately ranging upto, say 200 N under axial loading, while the user body weight may be 60 kg or greater. In such configurations, the magnets may progressively approach each other under load and may contact at peak compression.

[0135] However, even in embodiments where surface contact occurs at maximum loading, the magnetic repulsion force remains continuously present throughout the compression cycle and provides a pre-load resistance prior to contact. The repulsive force progressivelyPCT-IN26-LYAPL001increases as the gap decreases, thereby reducing the effective impact force transmitted to the surrounding sole material and to the joints of the user.

[0136] During heel strike or weight insertion, the magnetic repulsion acts as a non-linear shock absorber by absorbing a portion of the applied load before mechanical compression of surrounding material dominates. During gait transition and lift-off, the stored magnetic potential energy contributes to restoring separation between the magnets, thereby assisting upward thrust and reducing perceived step effort.

[0137] Thus, the magnetic system functions as a progressive load-sharing element that reduces peak impact forces and enhances energy return, even where full magnetic levitation is not achieved.

[0138] Non-Limiting Advantages: The present invention provides non-contact elastic resistance, reduced material fatigue, adaptive load response, customizable stiffness, improved energy return, and extended durability compared to conventional foam-only soles. The magnetic system reduces reliance on mechanical springs and minimizes compression set commonly observed in polymeric cushioning materials.

[0139] While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person skilled in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.

[0140] Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open-ended as opposed to limiting. As examples of the fore going: the term “including” should be read as mean “including, without limitation” or the like; the term “example” is used to provide exemplary instances of the item in discussion, not an exhaustive limiting list thereof; and adjectives such as “conventional,”PCT-IN26-LYAPL001“traditional,” “standard,” “known” and terms of similar meaning should not be construed as limiting the item described to a given time period or to an item available as of a given time, but instead should be read to encompass conventional, traditional, normal, or standard technologies that may be available or known now or at any time in the future. Likewise, a group of items linked with the conjunction “and” should not be read as requiring that each and every one of those items be present in the grouping, but rather should be read as “and / or” unless expressly stated otherwise. Similarly, a group of items linked with the conjunction “or” should not be read as requiring mutual exclusivity among that group, but rather should also be read as “and / or” unless expressly stated otherwise. Furthermore, although item, elements or components of the disclosure may be described or claimed in the singular, the plural is contemplated to be within the scope thereof unless limitation to the singular is explicitly stated. The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent.

[0141] Although the foregoing subject matter has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be understood by those skilled in the art that certain changes and modifications can be practiced within the scope of the invention.

Claims

PCT-IN26-LYAPL001We Claim:

1. A sole assembly configured to be incorporated into footwear, the sole assembly comprising:a forefoot portion,a midfoot portion,a heel portion, anda midsole region disposed between an upper sole and a lower sole,wherein the midsole region comprises at least one magnet chamber formed from compression-moulded polymeric material,wherein the at least one magnet chamber houses a first permanent magnet and a second permanent magnet arranged with like poles facing each other across a predetermined gap under no-load condition,wherein the magnet chamber constrains lateral movement of the first and second permanent magnets and maintains alignment of magnetic poles during repeated loading cycles,and wherein reduction of the pre-determined gap under compressive load generates a non-contact repulsive magnetic force exhibiting a non-linear force-displacement profile.

2. A footwear comprising:an upper, anda sole assembly secured to the upper,wherein the sole assembly comprises a forefoot portion, a midfoot portion, and a heel portion, and includes a midsole region disposed between an upper sole and a lower sole,PCT-IN26-LYAPL001wherein the midsole region comprises at least one magnet chamber housing a first permanent magnet and a second permanent magnet arranged such that like poles face each other across a pre-determined gap under no-load condition,wherein the pre-determined gap is configured to reduce upon application of vertical load during use of the footwear, thereby generating a repulsive magnetic force that resists compression of the sole assembly,and wherein the repulsive magnetic force provides a non-contact elastic support mechanism and a non-linear force-displacement response to provide adaptive cushioning and energy return.

3. The sole assembly according to claim 1, wherein the magnet chamber is formed from ethylene-vinyl acetate (EVA), thermoplastic polyurethane (TPU), expanded TPU, or blends thereof.

4. The sole assembly according to claim 1, wherein the first and second permanent magnets are rare-earth magnets, wherein the rare-earth magnets comprise neodymium-iron-boron magnets.

5. The sole assembly according to claim 1, wherein the magnets are cylindrical, rectangular, ring-shaped, spherical, polygonal, or customized geometries.

6. The sole assembly according to claim 1, wherein the magnets are configured in a Halbach array arrangement.

7. The footwear according to claim 2, wherein the pre-determined gap comprises air, foam, elastomeric material, or a combination thereof.

8. The footwear according to claim 2, wherein the magnets are arranged in vertical, oblique, horizontal, or combined orientations.

9. The footwear according to claim 2, wherein multiple magnet chambers are provided in at least the heel portion and forefoot portion.PCT-IN26-LYAPL00110. The sole assembly according to claim 1, wherein the pre-determined gap is approximately 9 mm under no-load condition.

11. The sole assembly according to claim 1, wherein the magnets are selected to provide a repulsion strength in the range of 5 kg to 35 kg under axial loading prior to surface contact.

12. The footwear according to claim 2, wherein the magnets remain spaced apart under normal walking loads without physical contact.

13. A method of providing adaptive cushioning in footwear, the method comprising: providing a sole assembly having a magnet chamber containing a first magnet and a second magnet arranged with like poles facing each other across a pre-determined gap;applying vertical load to the sole assembly during walking, running, or standing, thereby reducing the gap between the magnets;generating a repulsive magnetic force in response to reduction of the gap; and resisting compression of the sole assembly through the repulsive magnetic force to absorb impact energy and provide upward restoring support.

14. The method according to claim 13, wherein the repulsive magnetic force increases progressively as the gap decreases.

15. The method according to claim 13, wherein the magnets remain physically noncontacting under normal operational loads.

16. The method according to claim 13, further comprising restoring the pre-determined gap upon reduction of load, thereby providing energy return during toe-off17. The method according to claim 13, wherein the repulsive force profile is non-linear with respect to displacement.PCT-IN26-LYAPL00118. The method according to claim 13, wherein cushioning performance is adjusted by selecting magnet size, grade, thickness, or initial gap.

19. The method according to claim 13, wherein the repulsive force acts as a shock absorber during heel strike and as a thrust-assist during lift-off.

20. A method of manufacturing a footwear having a magnet-based cushioning system, the method comprising:forming a midsole body from a polymeric material;creating at least one magnet chamber within the midsole body;positioning a first magnet and a second magnet within the magnet chamber such that like poles face each other across a pre-determined gap under no-load condition; securing the magnets within the magnet chamber in axial alignment to permit controlled reduction of the gap under vertical load; andassembling the midsole body with an upper and an outsole to form the footwear, wherein the magnets are configured to generate a repulsive magnetic force upon reduction of the gap to provide non-contact cushioning.

21. The method according to claim 20, wherein the magnet chamber is formed during compression moulding of the midsole body.

22. The method according to claim 20, wherein the magnet chamber is formed by machining, cutting, or post-mould cavity formation.

23. The method according to claim 20, wherein the magnets are neodymium iron boron magnets.

24. The method according to claim 20, further comprising selecting magnet diameter, thickness, and magnetic grade to achieve a predetermined repulsion strength under axial loading.PCT-IN26-LYAPL00125. The method according to claim 20, further comprising providing an initial air gap between the magnets such that the magnets remain non-contacting under normal walking loads.

26. The method according to claim 20, further comprising encapsulating the magnets within a containment structure to prevent lateral displacement.

27. The method according to claim 20, wherein the magnet chamber is positioned in at least one of a heel region, midfoot region, or forefoot region of the midsole body.

28. The method according to claim 20, further comprising testing the assembled magnet pair under incremental loading to verify repulsion strength prior to integration into the footwear.

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