Safety shoe

Abstract

A safety shoe, comprising an outsole, a midsole, an upper and an optional insole on top of the midsole, wherein the midsole in substance comprises elastic material. The safety shoe is distinguished in that it further comprises an anti-puncture layer, wherein the anti-puncture layer is embedded into the midsole, and the midsole with embedded anti-puncture layer comprises at least 1 or 2 mm of elastic material above the anti-puncture layer, as measured in vertical direction upwards with the shoe standing on a horizontal surface, preferably measured in central position and / or at numerous points, such as 10 points distributed evenly over the sole area, wherein all and / or an average of the points must meet the criterium.

Description

[0001] BAA ref: 146925PC / EH

[0002] SAFETY SHOE

[0003] Technical Field

[0004] The present invention relates to shoes. More specifically, the invention provides a safety shoe.

[0005] Background Art

[0006] Muscle and skeleton issues, in general termed musculoskeletal disorders, is the main reason for sick leave in Norway. If the sick leave could be reduced, it would be beneficial not only for individual health improvement but also for the society, since sickness absence in Norway adjusted for seasonal variations in 3rdquarter of 2024 was as high as 7,19%. Also in other countries, musculoskeletal disorders represent significant challenges, both on individual basis and for the society. Said challenges apparently increase with increasing urbanization.

[0007] A large number of factors influence the health on individual basis and hence also for the society.

[0008] One such factor is the quality of footwear. There are innumerous types of shoes and other footwear, for almost any situation. One type of footwear that may have been neglected is safety shoes, typically used in industry on land and at sea, including installations for petroleum exploration or production.

[0009] In many industries and locations, often with hard, monotonous, slippery or complex surfaces, a risk exists for walking on spikes, nails and similar structures that can puncture and penetrate the sole and injury the user. In safety shoes for industry, it is usual to include a puncture plate or a similar structural layer with function to block penetration of nails through the sole. Normal design is to have an anti-puncture layer as an insole or part of an outsole or as a layer onto the outsole or midsole.

[0010] Safety shoes are often relatively uncomfortable to wear, since the major priority is that they shall be safe against puncturing by nails and similar structures, usually combined with safety against falling, smashing or clamping by heavy objects over the foot of the user. Typically, the toe part of a safety shoe is protected by a protective cap, also termed toe cap, and the sole area is puncture proof by including a puncture plate. To be most effective against injuries, both the toe cap and the puncture plate are rigid structures or comprises rigid structures, such as rigid plates or armorlike lamella-structures such as small plate parts joined together with some flexibility for movement. Armorlike woven or interlaced structure of metal wire or other strong fibers or wires, are also used. Aramid, Kevlar and Twaron are examples on feasible nonmetal fiber materials.

[0011] But safety shoes with more or less rigid puncture plates and toe caps are not very comfortable to wear, and may lack ergonomic qualities, which may result in health issues and increased sick leave.

[0012] A demand exists for a safety shoe having sufficient or full safety relative to applicable standards for safety shoes, whilst having improved ergonomic qualities and comfort for the user, compared to existing safety shoes at comparable safety level. Searching has not revealed any shoe that appears to be similar to the shoe of the present invention. The nearest identified shoes are as described and illustrated in patent publications US20160157554A1, EP2574251A3, EP3648628B1, US9565895B2, EP3367835B1 and EP3574791B1.

[0013] Summary of the invention

[0014] The invention provides a safety shoe, comprising an outsole, a midsole, an upper and an optional insole on top of the midsole, wherein the midsole in substance comprises elastic material. The safety shoe is distinguished in that it further comprises an anti-puncture layer, wherein the anti-puncture layer is embedded into the midsole, and the midsole with embedded anti-puncture layer comprises at least 1 or 2 mm of elastic material above the anti-puncture layer, as measured in vertical direction upwards with the shoe standing on a horizontal surface, preferably measured in central position and / or at numerous points, such as 10 points distributed evenly over the sole area, wherein all and / or an average of the points must meet the criterium.

[0015] In contrast to other safety shoes, the safety shoe of the present invention comprises an anti-puncture layer, also termed puncture plate or anti-puncture plate, embedded into the elastic material of the midsole. What apparently is standard design, is to arrange the anti-puncture layer as an insole or part of an outsole or as a layer onto the outsole or midsole. Most typically, a puncture plate is glued on the top of the midsole and is also fastened to the upper by sewing and / or gluing to where the upper is fastened to the midsole. In comparison, the safety shoe of the present invention can be designed with more exact elasticity and support over the area under the foot of the user with foot fitting the shoe size, and the shoe can be designed so as to provide dynamic elasticity and balanced support, whereby a balanced gait can be achievable and a positive effect on the load distribution of the foot during gait or when standing still can be provided, providing a positive health effect for the user and thus the society.

[0016] The term safety shoe, in the context of the present invention, includes safety shoes in a broad sense, including safety boots and other safety footwear. The safety shoes of the invention cover all types of safety shoes including an anti-puncture layer as described and / or illustrated herein and can further include any well-known safety means such as a toe cap, materials and design providing resistance against specific chemicals, liquids, heat, cold, electricity, and more.

[0017] The anti-puncture layer is embedded into the midsole over the full area under the foot of a user fitting the shoe size. More specifically, the anti-puncture layer is embedded into the midsole in all positions and the full area directly below the foot sole of a user fitting the size of the shoe. This means that a minor area just inside the periphery of the sole may be without embedded anti-puncture layer. Preferably, the full projected foot area as projected vertically down from the foot of a typical user fitting the size of the shoe, includes embedded anti-puncture layer in the midsole, preferably said full area and a safety area extending 1, 2, 3 or 4 mm outside and around the projected foot area.

[0018] Apparently, embedding the anti-puncture layer into a midsole that in substance comprises elastic material, wherein the midsole with embedded anti-puncture layer comprises at least 1 or 2 mm of elastic material above the anti-puncture layer, is novel and provides distinguishing technical effect by improved ergonomic quality and comfort over existing safety shoes. However, numerous additional features are preferable since they result in further improved technical effect, including ergonomic quality and / or comfort, some such additional features are as defined in dependent claims. Better balanced dynamic support of the foot can thereby be provided.

[0019] Reduced occurrence of or problems with plantar fasciitis, achilles tendinitis, shin splint, and knee problems are reported effects. Quantification of the improvements will be determined in detail based on larger figures when the safety shoes of the invention have been implemented and used extensively in industry.

[0020] Preferably, the midsole with embedded anti-puncture layer comprises at least 3 mm of elastic material above the anti-puncture layer, more preferably at least 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm of elastic material above the anti-puncture layer. For most users, about 6-8 mm apparently is optimal and thereby preferred as standard design.

[0021] In many preferable embodiments, the midsole is comprising: a harder elastic material (2U), a softer elastic material (2O), wherein the harder elastic material has elastic hardness in a range 1,3 to 3 times higher than the softer elastic material, and the harder elastic material is arranged in a band inside the periphery of the midsole, wherein the band extends inwards from the periphery along the sides and heel of the midsole, wherein the softer elastic material (2O) is arranged in the midsole inside the band of the harder elastic material. Preferably, the softer elastic material is arranged inside the band and over a lowermost thin layer of the harder elastic material forming a cuplike shape of the harder elastic material. In many preferable embodiments, the band of harder elastic material (2U) is wider on the medial side than the lateral side in the heel part of the midsole but preferably extends up from the outsole only up to where the anti-puncture layer 14 is inserted, for ensuring that the anti-puncture layer 14 covers all area under the foot of the user.

[0022] In many preferable embodiments of the safety shoe of the invention, the harder elastic band extends up from the outsole (outsole rubber) or a lower surface or elevation of the midsole to about 4 / 10 - 2 / 3 of the height of the midsole, above which an anti-puncture layer is embedded, over which a layer of the softer elastic material is arranged. Preferably, a support structure (15) is embedded in the medial side of the heel / midfoot, in substance medial to the heel bone of a user fitting the shoe size, preferably in the form of a relatively stiffer plate element on the medial side of or just inside the inner periphery of the midsole medial to the heel bone of a user with feet fitting the shoe size. Preferably, the support structure (15) has shape as an L as seen from behind in cross section of a right foot shoe, with the vertical part extending upwards on the medial side of the heel of the elastic material and the horizontal part extending from the vertical part inwards under or into the elastic material of the midsole. The vertical distance of the L is about equal to the horizontal distance of the L, such as equal within 30% or 20% or 10%.

[0023] The combination of the support structure (15) and / or the height and / or width of the wider band of harder elastic material 2U inside the periphery of the heel, and / or the ratio of elastic hardness between elastic materials 2U / 2O, can be combined to provide a specific dynamic elastic support to effect a controlled rotation of the heel and midfoot in clockwise direction, for a right foot of a user with feet fitting the shoe size.

[0024] In many preferable embodiments of the safety shoe of the invention, the harder elastic band extends up to the full height of the midsole, wherein the midsole is molded in two layers, with an intermediate layer comprising an anti-puncture layer and a shank between the two layers. Alternatively, the midsole comprises the harder elastic band extending up to the anti-puncture layer, with or without a shank, with softer elastic material above the anti-puncture layer, but preferably with an embedded support structure on the medial side of the heel / midfoot, in the form of said relatively stiffer L-shaped plate element (15) on the medial side of or just inside the inner periphery of the midsole medial to the heel bone of a user with feet fitting the shoe size. The relatively stiffer plate element preferably has thickness and elasticity as for the shank and is arranged from the top elevation of the outsole and up to the elevation of the anti-puncture / shank, and preferably is wider than the height, by a ratio width / height of 1,1 - 3,5 or 1,2-3, as seen on the medial side of the heel, seeing the vertical side only of said L-shaped plate. Alternatively, the relatively stiffer plate element is arranged at higher elevation on the medial side of the heel / midfoot. Preferably, the safety shoe of the invention comprises a shank. Preferably, the shank and the anti-puncture layer is embedded at the same or about the same elevation. Preferably, the shank and the anti-puncture layer are joined before embedding into the midsole, in correct relative positions, enabling a simplified fabrication method for the shoe by molding and embedding the anti-puncture layer and the shank in one operation. Preferably, the anti-puncture layer is arranged on top of the shank.

[0025] Preferably, the safety shoe of the invention is further comprising a support structure (8) arranged below the softer elastic material in direction medial to lateral and positioned from vertically below to 4 cm in front of the os naviculare bone center of a typical user with feet fitting the shoe size, wherein the support structure has higher elastic hardness than the harder elastic material, with a larger vertical dimension medial compared to lateral as seen with the shoe standing on a horizontal surface, providing increased support under the medial side of the foot arch compared to the lateral side of the foot arch. Preferably the support structure (8) is extending 4 / 10 to 1 / 1 of the distance from medial side to lateral side of the outsole, more preferably 0,3-0, 6 or 0,4-0, 5 of said distance, and is preferably arranged as a part of the rubber outsole (9), and / or arranged between the outsole and the harder elastic material, and / or arranged as embedded into the harder elastic material.

[0026] The shoe of the invention preferably is comprising a shank, wherein the shank (6) is extending over 60-95% of a last length and extending 60-95% over the last width, the shank is twisted in clockwise direction for a right foot midsole as seen from behind from the heel to an intermediate part to a position in front of the naviculare bone of a user, the twisting is at an angle a2 in a range 1° to 10° from horizontal, and the shank is preferably made of polyamide and preferably is, exclusive any ribs, 0.5-3 mm thick, with ribs up to about 6 mm thick. Preferably, at least a part of the midsole top surface of the shoe of the invention is inclined, wherein the midsole is higher on the medial side compared to the lateral side in the heel and intermediate part to a position in front of the naviculare bone of a user, the inclination is at an angle a1 in a range 1 ° to 7 ° from horizontal. Preferably, wherein a2 > a1.

[0027] The shoe of the invention preferably is comprising ETPU (expanded thermoplastic polyurethane), EVA (ethylene vinyl acetate), ATPU (aliphatic polyether-based thermoplastic polyurethane), Pebax (polyether and polyamide block copolymers) in a Shore A hardness range 40 - 80, more preferably about 60, as the harder elastic material, and ETPLI, EVA, ATPLI or Pebax in a Shore A hardness range 20 - 60, more preferably about 30, as the softer elastic material. The shank 6 and / or the support plate 15, preferably have hardness about Shore D 70-90, preferably about 80. The elastic hardness values are measured according to ASTM D2240. The shank 6 and / or the plate 15 are preferably made of PA6 or PA66 (polyamides). Other materials than specified herein can be used and can be feasible. In the future, even more feasible materials can be available and more preferred.

[0028] Preferably, the anti-puncture layer of the shoe of the invention comprises a tightly woven fiber structure, is made from Kevlar, polyimide, carbon fibers, glass fibers, boron fibers, and / or metal fibers.

[0029] In some extra robust embodiments, the shoe of the invention preferably comprises an additional anti-puncture layer arranged in between the outsole and the midsole.

[0030] Figures

[0031] Figure 1 is an expanded illustration of an embodiment of a safety shoe of the invention.

[0032] Figures 2-4 are cross sections of the sole of the safety shoe of Fig. 1, in the heel, midfoot and forefoot, respectively.

[0033] Detailed description of the invention

[0034] The test procedure for ensuring correct functionality of the safety shoe of the invention with embedded anti-puncture layer, preferably is according to the test standard EN ISO 20345:2022, to which reference is made. Thereby, it can be ensured that personnel working on building sites, in industry, on ships and petroleum installations and other sites or locations with risk for sole puncturing, have safety shoes of quality at least meeting the regulatory requirements. The test is a test of required force for penetrating the sole with a standardized nail, wherein safe load without penetration corresponds to 1100 Newton force, at a midpoint of the sole. Numerous test points are required, to ensure even quality, but number of or position of test points are not defined in detail. Reference is made to Figure 1, illustrating a safety shoe 1 of the invention, comprising an outsole (9), a midsole (2U and 20), an upper (10) and an optional insole (not illustrated, also termed inlay or inlay sole) on top of the midsole, wherein the midsole (2U and 20) in substance comprises elastic material. The safety shoe is distinguished in that it further comprises an anti-puncture layer (14), wherein the antipuncture layer is embedded into the midsole, and the midsole with embedded antipuncture layer comprises at least 2 mm, more preferably 5 or 6-8 mm, of elastic material above the anti-puncture layer, as measured in vertical direction upwards with the shoe standing on a horizontal surface. Not visible in Fig. 1 but visible in Fig.

[0035] 2, a support structure (15) is embedded in the medial side of the heel / midfoot, in substance medial to the heel bone of a user fitting the shoe size, in the form of a relatively stiffer plate element on the medial side of the inner periphery of the midsole medial to the heel bone of a user with feet fitting the shoe size.

[0036] The embodiment of a safety shoe 1 of the invention, is in Figure 1 illustrated with “exploded” sole. The lowermost part 2U comprises the outsole 9 and a lower part of the midsole, termed 2U (U for under). Above the lowermost part, a shank 6 is illustrated, and the anti-puncture layer 14. Above the anti-puncture layer 14, an upper part 20 (0 for over) of the midsole is illustrated. A toe cap 13 is also illustrated.

[0037] Above the “exploded” sole, an illustration of the fully built safety shoe 1 of the invention is illustrated.

[0038] Figure 2 illustrates a cross section of the heel area of the sole, including outsole 9, midsole 2U under part (U for under) and 20 (0 for Over) over part of the midsole, stiffening plate 15, shank 6, anti-puncture layer 14 and 20. The midsole harder elastic material 2U preferably is 1,3 to 3 times harder than the softer elastic material 20, more preferably 1,5 to 2,5 times harder, most preferably about 2 times harder, referring to elastic hardness as measured according to ASTM D2240. However, it is possible to use materials 2U and 20 being closer to each other with respect to elastic hardness, but the dynamic support of the resulting sole preferably should be adjusted by adapting the width, rotation and stiffness of shank 6, the stiffness and size of plate 15 and the width and / or height of medial band of material 2U, and clockwise rotation of the surface on top of the midsole (inside) material 20 and inside and below, for material 2U, as seen for a right foot from behind.

[0039] Further reference is made to Figure 3, illustrating a cross section of a midfoot part of the sole. The shape and distribution of the materials are somewhat different compared to the heel cross section, most notable is outsole material 9 comprising a thicker support structure 8 on the medial side, under or slightly in front of the os naviculare bone of a typical user with feet fitting the shoe size. The increased thickness of relatively stiffer materials 8 and 6 on the medial side of the midfoot, prevents “os naviculare drop” and / or provides dynamic “os naviculare support”. The increased structure thickness 8, preferably extends 0,2 – 0,7 or 0,3 – 0,6 or 0,4 – 0,5 times the width of the sole from medial to lateral side, as illustrated, saving weight whilst retaining the intended effect.

[0040] Figure 4 illustrates a cross section through a forefoot part of the sole. The distribution of the material components is relatively even on the medial and lateral side, meaning a balanced support on the medial and lateral side of the foot of a user with feet fitting the shoe size.

[0041] The effect of the sole construction, as seen in cross sections from the heel, to the midfoot and the forefoot, is a dynamic support and comfort providing a correct orientation of the ancle and the bone structure from the foot and upwards, resulting in less pain or problems for at least 8 out of 10 people. The load is balanced around the main natural bone structure. For a safety shoe, such effect is novel and surprising.

[0042] Numerous other embodiments are possible. Many preferable embodiments are as defined in claim 1 as combined with one or more of the dependent claims. Some of the further preferable embodiments of the safety shoe of the invention, include features as described and / or illustrated in the patent publications WO2021112683A1 and WO2021112682A1, both in the name of the Applicant and both herein included by reference. Some other preferable embodiments comprise features not derivable from WO2021112683A1 and / or WO2021112682A1.

[0043] The sole of the safety shoe of the invention, also termed shoe of the invention or only shoe, has a soft elasticity at initial compression by the foot of the user, softer than a safety shoe and even softer than a traditional walking shoe, and similar to the initial softness of a sport shoe with extensive damping. At increasing compression, the elasticity becomes progressively harder, particularly on the medial side of heel and midfoot, and more expressed in the midfoot area than the heel area. The effect, when increasing the weight on the heelbone, is that the resistance to further compression is more expressed on the medial side compared to the lateral side. As a consequence, there is a dynamic progressive resistance against too much inward rotation of the heel bone (biomechanically defined as a “heel bone valgus rotation”). The torque creates a clockwise rotation for the right foot seen from behind, effecting the vertical orientation of the heelbone as well as the vertical alignment of the achilles tendon, compared to when using a traditional safety shoe, walking shoe or sport shoe. Excessive heel bone valgus rotation is thereby reduced or prevented. Likewise, when progressing the step from heel impact to midfoot stance, the foot arch is supported by progressively harder elasticity in the midfoot area, under the longitudinal foot arch and particularly under the medial side thereof, earlier (at less compression) and harder elasticity, providing “os naviculare lift”. Preferably, the safety shoe of the invention comprises a combination of archroller and shank, whereby the archroller provides increasing force from the underlayer up on the shank at increasing compression, most on the medial side of the midfoot, whilst the shank bends and distribute the force along the medial, longitudinal foot arch (medial plantar fascia). If the detailed design is as here described, said bending of the shank in substance follows the shape of the foot arch.

[0044] The subject matter of the present invention is a safety shoe, as defined in the independent claim, with preferable embodiments as defined in the dependent claims and / or in the description and / or as illustrated. In some preferable embodiments, the safety shoe of the invention comprises features also found in the shoes as described and illustrated in the patent publications WO2021112683A1 and WO2021112682A1, to which reference is made, for providing dynamic elasticity and biomechanical support as described above, for the benefit of the user, in addition to the benefits of a safety shoe. In a further subject matter of the present invention, a shoe is provided, comprising an upper, an outsole and a midsole, wherein the midsole comprises a harder elastic material (2U), a softer elastic material (2O), wherein the harder elastic material has elastic hardness in a range 1,3 to 3 times higher than the softer elastic material, and the harder elastic material is arranged in a band inside the periphery of the midsole, wherein the band extends inwards from the periphery along the sides and heel of the midsole, further comprising a shank 6 and an arch roller 8, and a support structure 15, preferably in the form of the L-shaped plate element (15), wherein the shoe is in agreement with any one of claim 1-10 and the description herein, except that the shoe is without an anti-puncture layer, and preferably said band of the harder elastic material is wider on medial side than lateral side of the heel, up to 1 / 3 to 2 / 3 or ¾ of the total height of the midsole as standing on a horizontal surface, and / or the volume or cross-section area of the harder elastic material 2U is larger on the medial side of the heel of the shoe than on the lateral side. In substance, the cross section of the sole is as seen in figures 2-4, for heel, midfoot and forefoot, respectively, but without the anti-puncture layer 14, wherein the volume of the removed anti-puncture-layer 14 has been replaced by the softer elastic material 2O.

Claims

146925PC / EH Claims1.Safety shoe (1), comprising an outsole (9), a midsole (2U and 2O), an upper (10) and an optional insole on top of the midsole, wherein the midsole (2U and 2O) in substance comprises elastic material, characterized in that the shoe further comprises an anti-puncture layer (14), wherein the anti-puncture layer is embedded into the midsole, and the midsole with embedded anti-puncture layer comprises at least 2 mm of elastic material above the anti-puncture layer, as measured in vertical direction upwards with the shoe standing on a horizontal surface.2.The safety shoe of claim 1, wherein the midsole with embedded anti-puncture layer (14) comprises at least 3 mm of elastic material above the anti-puncture layer, more preferably at least 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9mm or 10 mm of elastic material above the anti-puncture layer.3.The safety shoe of claim 1 or 2, wherein the midsole (2U and 20) is comprising: a harder elastic material (2U), a softer elastic material (2O), wherein the harder elastic material has elastic hardness in a range 1,3 to 3 times higher than the softer elastic material, and the harder elastic material is arranged in a band inside the periphery of the midsole, wherein the band extends inwards from the periphery along the sides and heel of the midsole, wherein the softer elastic material (2O) is arranged in the midsole inside the band of the harder elastic material.4.The safety shoe of claim 3, wherein the band of the harder elastic material extends up from the outsole or a lower surface or elevation of the midsole to about 4 / 10 - 2 / 3of the height of the midsole, above which an anti-puncture layer is embedded, over which a layer of the softer elastic material is arranged, and preferably a support structure (15) is arranged in or on and below the midsole, in substance medial to the heel bone of a user with feet fitting the shoe size.5.The safety shoe of claim 3, wherein the harder elastic band extends up to the full height of the midsole, wherein the midsole is moulded in two layers, with an intermediate layer comprising an anti-puncture layer and a shank between the two layers.6.The safety shoe of claim 1-4, comprising a shank (6).7.The safety shoe of claim 1-6, further comprising a support structure (8, 9), also termed archroller, arranged below the softer elastic material in direction medial to lateral and positioned from vertically below to 4 cm in front of the naviculare bone center of a typical user with feet fitting the shoe size, wherein the support structure has higher elastic hardness than the harder elastic material, with a larger vertical dimension medial compared to lateral as seen with the shoe standing on a horizontal surface, providing increased support under the medial side of the foot arch compared to the lateral side of the foot arch, preferably the support structure (8) is arranged in the rubber outsole (9), preferably extending 0,3-0, 7 or 0,4-0, 6 or 0,4-0, 5 times the distance from medial side to lateral side of the outsole.8.The safety shoe according to claim 1-7, wherein the anti-puncture layer comprises a tightly woven fibre structure, from Kevlar, polyimide, carbon fibres, glass fibres, boron fibres and / or metal fibres.9.The safety shoe of claim 1-8 comprising an additional anti-puncture layer, preferably arranged in between the outsole and the midsole.10.The safety shoe of claim 1-9, wherein the shank and the anti-puncture layer are joined before embedding into the midsole, in correct relative positions, enabling a simplified fabrication method for the shoe by molding and embedding the antipuncture layer and the shank in one operation, preferably, the anti-puncture layer is arranged on top of the shank.

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