Shoe with spring plate with h-shape

Abstract

The disclosed invention consists of a one-piece spring plate (32) as part of a shoe (10), in particular a sports shoe (10), comprising a body made from fibre containing composite material, wherein the one-piece spring plate (32) forms as part of a sole body (30) and the one-piece spring plate (32) is curved in its course from a forefoot section (A) via a midfoot section (B) to the hindfoot section (C) analogously to the sole of the foot of a user, providing increased suspension characteristics in any type of terrain. To achieve this the one-piece spring plate (32) is formed like a H with a lateral strand (320), a medial strand (321), a connection bar (324) between the midfoot section (B) and the forefoot section (A) from which on a first side a first omitted bifurcation of both strands (320, 321) in the forefoot section (A) with a fork gap (322), while on a second side an omitted second bifurcation of both strands (320, 321) in the course of the hindfoot section (C) with a central recess (323) is integrally formed, wherein rounded corners and edgeless edges were used and the total length of the spring plate (32) is less than or equal to ¾ of the maximum length (Z) of the midsole (31).

Description

[0001] SHOE WITH SPRING PLATE WITH H-SHAPE

[0002] TECHNICAL FIELD

[0003] The invention includes a one-piece spring plate as part of a shoe, in particular a sports shoe, comprising a body made from fibre containing composite material, wherein the one-piece spring plate is inserted, molded and / or fixed above or below a midsole as part of a sole body and the one-piece spring plate is curved in its course from a forefoot section via a midfoot section to the hindfoot section analogously to the sole of the foot of a user, and a shoe comprising a spring plate and an outsole with suspension structure.

[0004] STATE OF THE ART

[0005] Shoes, more precisely shoe soles are subjected to substantial compressive loads. In particular in case of sports shoes, there are ground reaction forces, which exceed several times the body weight, when contacting the ground with the heel and during push-off at the end of the step cycle. Accordingly, a sole construction must on the one hand provide a sufficient cushioning comfort to avoid premature fatigue or even injuries of the muscles or the bones. On the other hand, it must be capable to withstand these forces over an acceptable lifetime.

[0006] From EP1048233 a shoe in particular a sprint shoe, having a plate arranged in the sole area of the shoe, wherein the plate extends essentially over the complete length of the sole area, is essentially planar shaped in the forefoot part to allow an elastically bending of the plate in longitudinal direction, is known.

[0007] An objective in the construction of sprint shoes is the elastic storing of energy by the shoe during the course of movements. During each landing phase the shoe is deformed in the forefoot part by the rolling- off with the ball of the foot and the toes. During the subsequent push- off with the toes the foot is straightened and the shoe returns into its straight original shape. This procedure is repeated during running with each step.

[0008] To improve the springback effect, US 6553692 discloses a complex arrangement for the heel part of a shoe which transforms a compression movement in the sole into a compression or elongation of a horizontally arranged coil spring. Also here there is a significant residual volume of the cushioning system so that the explained difficulties are not avoided. Furthermore, the design is so complex that it is inconceivable to economically manufacture the corresponding shoe.

[0009] The development has recently been moving away from flat carbon plates, which can be seen for example in DE102006059658. A complex and elaborate spring construction has been introduced here. Such a structure is much more expensive to produce and clunky to use, so this route was probably not pursued.

[0010] To improve the stability by stiffening elements, EP3868243 introduced curved hollow tubes made of fibre composite material. But these sole constructions, comprising at least two reinforcing members, are so stiff that no spring effect is achieved. Although this solution seems to be good against lateral tilting, it leads to a deterioration of the rolling characteristics of the shoe.

[0011] The so far known sports shoes with spring plates act quite similar to a spring storing energy when the user bend it during the stride and releasing it when the user move forward. The development has gone in the direction of several carbon fibre plates and more elaborate structures to improve the suspension in any railing. A two pieces spring plate with a lateral strand and a medial strand is described in US2022142296. Both strands are arranged separately within the midsole or outsole and their cross-sections are curved according to the arch of the sole of the foot. A connection between the two strands is also mentioned, which is formed from a flexible material that accordingly differs from the strands.

[0012] In the realm of cutting-edge high-performance running shoes, a prevailing trend has emerged such carbon plates embedded within the midsole, on top or below the midsole. This carbon plate serves a purpose akin to that of a spring, diligently accumulating energy as the wearer flexes it during each stride and subsequently unleashing that stored power as the wearer propels forward.

[0013] Typically, these plates are meticulously designed to mimic the natural contours of the human foot. While they excel admirably on smooth, even surfaces such as roads, they come with certain limitations when faced with uneven terrain, coupled with an unwelcome increase in weight. This limitation arises from the inherent design principle that compels the plate to flex in a predominantly perpendicular manner in relation to the wearer's motion.

[0014] This drawback becomes particularly pronounced on rugged, uneven terrain, posing a considerable inconvenience. The unwavering rigidity of the plate perpetually maintains the shoe's flat orientation, effectively preventing it from adapting to the ever-shifting topography. Consequently, this results in diminished traction and stability, compromising the overall performance of the shoe.

[0015] DESCRIPTION OF THE INVENTION The disadvantages described above, which are known from the prior art, will be eliminated by the present one-piece spring plate and and a shoe equipped with it.

[0016] The special design of the one-piece spring plate and the installation in a sports shoe as part of a sole body creates a sports shoe optimally adapted to different terrains.

[0017] The design of the one-piece spring plate according to the invention aims to keep the spring effect of a known standard plate while, working on the shape of the carbon part, allowing for a higher adaptability to the terrain and an improved shock absorption in the forefoot and heel.

[0018] BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Further understanding of various aspects of the invention can be obtained by reference to the following detailed description in conjunction with the associated drawings, which are described briefly below.

[0020] It should be noted that in the differently described embodiments, the same parts are provided with the same reference symbols or the same component names, the disclosures contained in the entire description being able to be applied analogously to the same parts with the same reference symbols or the same component symbols.

[0021] A preferred exemplary embodiment of the subject matter of the invention is described below in conjunction with the attached drawings.

[0022] FIG. 1 shows an exploded view of the components of a sports shoe with clearly visible one-piece spring plate between a midsole and an outsole, wherein the spring plate could also be placed between upper and midsole. FIG. 2 shows a top view of a one-piece spring plate, the outer outline of the midsole and indicated bending of lateral strand and medial strand and the different tips, while

[0023] FIG. 3a shows a top view of the spring plate only, with information on the shape and sizes of a fork gap and an end recess, while

[0024] FIG. 3b shows different bending deflections of the lateral strand and the medial strand of the spring plate in use.

[0025] DESCRIPTION

[0026] With reference to the appended FIG. 1 there is illustrated a footwear 10 according to the present invention, comprising in particular an upper 20, a sole body 30 and an outsole 40, most preferred with suspension structure.

[0027] Terms such as 'top', 'bottom', 'inside', 'outside' or the like will be used in the following description; the expert in the field will have no difficulty in understanding that these terms refer to the position of sports shoe 10 in its normal operating position, i.e. in use, as depicted in the attached figure 1.

[0028] The upper 20 comprises a flexible, hollow body shaped to receive the user's foot and provided, for this purpose, with a top opening 21 to allow the footwear 10 to be fitted.

[0029] Preferably, said upper 20 is obtained by means of 'knit' technology, i.e. it has a flexible sock-like structure which is obtained by thermoforming from a seamless knitted fabric tube made in one piece by a knitting machine. However, other types of uppers, made from the most suitable materials for the desired use, can be provided.

[0030] The upper 20 can be subdivided, by way of reference, into three regions, named according to their position with respect to the user's foot: Said upper 20 defines a forefoot region 23, which corresponds to the portion of the upper 20 placed in correspondence with the upper part of the toes of the user and includes the toe P of the footwear, a midfoot region 24, which corresponds to the portion of the upper 20 placed in the intermediate upper part of the foot of the user, and a hindfoot region 25, which corresponds to the portion of the upper 20 placed in proximity to the heel T of the footwear 10. In addition, the upper 20 includes a bottom region 22, which corresponds to the portion of the shoe located at the sole of the user's foot. The upper 20 also defines an inner medial side, not visible in the figure 1 and an outer medial side 26, both extending on opposite sides of the foot, from toe P to heel T through each of the regions 23 to 25.

[0031] Lacing means 27 of a known, advantageously releasable type are preferably associated with the upper 20, being preferably arranged at the top thereof, preferably in the midfoot region 24 and in the vicinity of the opening 21. Said lacing means 27 are suitable for modifying the dimensions of the inner cavity defined by the upper 20 so that the latter adapts to the conformation of the user's foot, and also facilitating the entry and exit of the foot with respect thereto.

[0032] The sole body 30 comprises at least one midsole 31 suitable for association with the upper 20 to support the sole of the user's foot. Preferably, said midsole 31 is formed of a tiled element, configured to essentially copy the contour of the sole of the user's foot and made of an advantageously flexible material, preferably having a hardness between 47 and 53 Shore C (according to ISO 868), capable of conferring comfort to the user and effectively cushioning shocks during walking or running. Preferably, said midsole 31 comprises a thermoplastic elastomer, most preferred a polyamide elastomeric material, such as polyether block amide, PEBA.

[0033] Especially in combination with the outsole 40 with suspension structure, the spring plate 32 is particularly efficient.

[0034] The suspension brackets 41 are one-piece elements and could be only one suspension bracket 41 as shown in Figure 1 or are provided in a number greater than four, completely distributed around the upper 20 and the sole body 30 with respect to the ground. Of course the form of the suspension brackets 41, associated ground support surfaces 42 and free spaces 43 in the suspension bracket 41 or between multiple brackets 41 can vary, wherein in Figure 1 one preferred example is shown. To achieve a spring effect, a one-piece spring plate 32 comprising one single body is inserted, molded and / or fixed above or below the midsole 31 as part of the sole body 30.

[0035] The one-piece spring plate 32 comprises a lateral strand 320 and a medial strand 321, each extending on either side of a longitudinal axis L and connected by a connection bar 324. Both strands 320, 321 run from a forefoot section A via a midfoot section B to a hindfoot section C, along the outer contours of the midsole 31 in a waisted shape of the lateral strand 320 and medial strand 321, whereby the spring plate 32 is only one component. The spring plate 32 is fixed between the upper 20 and the outsole 40, on top of the midsole 31 or below the midsole 31 by known means or may even be inserted into the body of midsole 31.

[0036] The spring plate 32 and all of its components are made of a carbon fibre or aromatic polyamide fibre or glass fibre composite, to achieve the desired stiffness. This material combines excellent elastic properties with a reduced weight. The material for the spring plate is preferably a composite material of carbon fibres which are embedded into a matrix of resin. Also Kevlar=Aramid fibres, short for aromatic polyamide fibres or glass fibres might be used. These materials combine high stiffness and a small energy loss with a low weight.

[0037] Further, also the use of spring steel or other elastic metal alloys is possible. Plastic materials like Pebax or Hytrel have advantages with respect to their manufacture by injection molding, they obtain, however, the necessary elastic properties only by an additional reinforcement with fibres.

[0038] The thickness of all the spring plate 32 components is between about one millimeter and three millimeters, because there is a risk of breaking under high load. Most preferred is a thickness of the one piece spring plate 32 of 1 mm. In forefoot section A, a fork gap 322 is left between lateral strand 320 and medial strand 321, up to connection bar 324, where the tips of lateral strand 320 and medial strand 321 being curved or corrugated. From midfoot section B to hindfoot section C, lateral strand 320 and medial strand 321 are separated and spaced apart and run curved from connection bar 324 to hindfoot section C. Both strands 320, 321 and the connection bar 324 form a substantially H-shaped one-piece spring plate 32. At the end of forefoot section A and at the outer end of hindfoot section C, tips are formed at 320 and 321 respectively, which project away from the connection bar 324. Sharp or pointed edges are avoided along the whole one-piece spring plate 32.

[0039] A central recess 323 is cut out in the midfoot section B of the one-piece spring plate 32, starting from connection bar 324, which separates both strands 320, 321.

[0040] The components of the spring plate 32 and their relative orientation are shown in detail in Figure 2. The lateral strand 320 and the medial strand 321 are acting as long tongue-like springs that store energy while bended and release it during the last part of the gait. To allow both strands 320, 321 to spring independently of each other, they are connected only by the one single connection bar 324 or bridge structure 324. The fork gap 322 and central recess 323 must be designed accordingly.

[0041] The connection bar 324 between lateral strand 320 and medial strand 321, like the other components, is made of the same material as the rest of the spring plate 32 and accordingly all components are moulded to each other.

[0042] It's important, that the central recess 323 in the centre of the the one- piece spring plate 32 is large enough, that a part of the central part of the feet of a user can get directly in contact with the soft midsole 31 for better comfort and shock absorption.

[0043] The total length of the lateral strand 320 and the medial strand 321 must be designed in such a way that a heel area H of the foot comes to rest directly on the midsole 31 in an area free of the one-piece spring plate 32. This means that the heel area H is practically spaced apart to the spring plate 32 on the midsole 31. The hindfoot section C of the one- piece spring plate 32 only projects in the direction of heel area H but does not reach the heel area H of the foot. Therewith the heel area H is completely free from the plate 32 allowing for great shock absorption during landing.

[0044] A bifurcation of the two strands 320, 321 occurs in forefoot section A, with lateral strand 320 terminating in a lateral tip 1 and medial strand 321 terminating in a medial tip 2. Both strands 320, 321 are connected only in forefoot section A via connection bar 324 and lateral tip 1 and medial tip 2 are each rounded and not pointed, as the other outer edges of the strands 320, 321.

[0045] The bifurcation with two split tips 1, 2 allows the medial tip 2 to provide the correct support to the foot thumb when pushing the gait while, the lateral tip 1 independently provides support to the other toes. In this way the foot thumb and the toes are connected but not in a rigid way providing adaptability to uneven ground. Together both tips 1, 2 provide a solid base support when climbing with the toe area.

[0046] The connection bar 324 or bridge 324 acts as a semi-rigid joint, allowing the strands 320, 321 to bend independently, thus maintaining their spring function, and adapt to uneven terrain still providing lateral stability especially when the muscles are tired and became more difficult to keep the feet in correct position during gait. Independent bending of the plate 32 can be achieved in the region of the two split tips 1, 2 and in the hindfoot section C of the separated strands 320, 321.

[0047] For a better understanding of the different possible bends of both strands 320, 321, the lateral strand 320 is shown filled in black and the medial strand 321 is left in white / grey in Figures 3a and 3b, while the connection bar 324 is also shown partly in black and partly in white in Figure 3a. The complete one-piece spring plate 32 runs curved, according to the anatomy of the foot and the midsole 31, curved with rounded corners from forefoot section A to hindfoot section C.

[0048] The lateral strand 320 and medial strand 321 are divided in hindfoot section C and converge in midfoot section B, revealing a single bifurcation in hindfoot section C, the central recess 323 and showing the single bifurcation, the fork gap 322 in forefoot section A.

[0049] The upper bifurcation or fork gap 322 in the spring plate 32 in the forefoot section A has a maximum opening d, which is tapered in the direction of the connection bar 324, whereby straight edges are avoided. The maximum opening d is preferably in the range from 5 mm to 30 mm, particularly preferably between 10 mm and 20 mm, depending on the total length I of the plate 32. This allows the lateral tip 1 and the medial tip 2 to be bent independently and against each other.

[0050] The width e of the connection bar 324 should be between 10 mm and 30 mm for all sizes of spring plates 32, preferably between 12 mm and 22 mm, depending on the total length I of the plate 32. As shown, the connection bar 324 runs approximately perpendicular to the longitudinal axis L between fork gap 322 and lower central recess 323.

[0051] The central recess 323 in the midfoot section B of the spring plate 32 has a maximum length f between 100mm and 220mm and a maximum width g between 30mm and 70mm, and again the side walls are all curved without sharp edges to prevent predetermined breaking points and the risk of injury.

[0052] The entire spring plate 32 must be dimensioned in such a way that, depending on the shoe size, it fits the shape of the midsole 31 and does not protrude beyond it on any side. The total length I of the one-piece spring plate 32, the sum of forefoot section A, midfoot section B and hindfoot section C, should not exceed 3 / 4 of the maximum length Z of the respective midsole 31.

[0053] To illustrate the curvature of the spring plate 32 according to the anatomically given foot curvature of the user, Figure 3b shows sections through the lateral strand 320 and the medial strand 321, whereby the elevation of the medial strand 321 relative to the lateral strand 321, as explained above, is also apparent. Due to the semi-rigid connection, a mutual bending of the strands 320, 321 can be achieved depending on the load, as shown in Figure 3b. Thus, the sports shoe 10 is optimally adapted to different terrains. This allows the medial strand 321 and therewith the medial side and the lateral strand 320 and therewith the lateral side of the one-piece spring plate 32 and thus of the sports shoe 10 to achieve independent spring effects.

[0054] As shown in Figure 3b, lateral strand 320 and medial strand 321 can be bent relative to each other depending on the load, with the bending occurring relative to connection bar 324. The spring effect is thus optimized.

[0055] The design with two longitudinally spaced omitted bifurcations 322, 323, a preformed connection bar 324, rounded corners throughout, the absence of sharp edges, the sufficiently large central recess 323 and the short design of the total length I less than or equal to % of the length of the midsole 31 results in an optimized one-piece spring plate 32. The one-piece spring plate 32 is bend in its course from the forefoot section A in the direction of the longitudinal axis L in the midfoot section B to a minimum and bent away from this again in the region of the hindfoot section C.

[0056] The at least one resilient suspension bracket 41 should be made of EVA or other polymeric materials having different densities in order to confer different mechanical characteristics according to the arrangement on the footwear.

[0057] List of reference signs

[0058] 10 footwear / sports shoe

[0059] T heel

[0060] P toe

[0061] 20 upper

[0062] 21 top opening

[0063] 22 bottom region

[0064] 23 forefoot region

[0065] 24 midfoot region

[0066] 25 hindfoot region

[0067] 26 outer medial side

[0068] 27 lacing means

[0069] 30 sole body

[0070] 31 midsole (preferred an insole)

[0071] Z maximum length (of the respective midsole)

[0072] 32 one-piece spring plate (H-plate)

[0073] I total length (<3 / 4 of midsole length)

[0074] A forefoot section (area of toe bones)

[0075] B midfoot section

[0076] C hindfoot section (open in area of tarsal bone)

[0077] 320 Lateral strand (one tine, curved)

[0078] 1 lateral tip

[0079] 321 Medial strand (longer than 320)

[0080] 2 medial tip

[0081] 322 Fork gap (in A with d) d maximum opening of upper bifurcation / fork gap

[0082] 323 central recess (in B with f and g) f length g maximum width in B

[0083] 324 connection bar / bridge structure e width

[0084] L longitudinal axis

[0085] H heel area of a foot

[0086] 40 outsole with suspension structure

[0087] 41 suspension bracket

[0088] 42 ground support surface

[0089] 43 free space

Claims

PATENT CLAIMS1. One-piece spring plate (32) as part of a shoe (10), in particular a sports shoe (10), comprising a body made from fibre containing composite material, wherein the one-piece spring plate (32) is inserted, moulded and / or fixed above or below a midsole (31) as part of a sole body (30) and the one-piece spring plate (32) is curved in its course from a forefoot section (A) via a midfoot section (B) to the hindfoot section (C) analogously to the sole of the foot of a user, characterized in that the one-piece spring plate (32) is formed in the form of a H comprising:- a lateral strand (320) running curved with rounded corners from hindfoot section (C) to forefoot section (A) along the outer contour of the midsole (31) analogous to the foot anatomy ending in a lateral tip (1) in the forefoot section (A),- a medial strand (321) running approximately parallel and spaced to the lateral strand (320) curved along the inner contour of the midsole (31) analogous to the foot anatomy with rounded corners from hindfoot section (C) to a medial tip (2) in forefoot section (A),- a connection bar (324) between the midfoot section (B) and the forefoot section (A) from which on a first side- a first omitted bifurcation of both strands (320, 321) in the forefoot section (A) with a fork gap (322) is integrally formed, while on a second side- an omitted second bifurcation of both strands (320, 321) in the course of the hindfoot section (C) with a central recess (323) is integrally formed, wherein rounded corners and edgeless edges were usedthroughout the one-piece spring plate (32) and the total length (I) of the spring plate (32) is less than or equal to % of the maximum length (Z) of the midsole (31) with which the one- piece spring plate (32) interacts.

2. One-piece spring plate (32) according to one of the preceding claims, wherein the fork gap (322) in the forefoot section (A) with split tips (1, 2) has a maximum opening (d), which is tapered in the direction of the connection bar (324) and the maximum opening (d) is preferably in the range from 5 mm to 30 mm, particularly preferably between 10 mm and 20 mm.

3. One-piece spring plate (32) according to one of the preceding claims, wherein in the course of the one-piece plate (32) from the forefoot section (A) in the direction of the longitudinal axis (L) in the midfoot section (B) to a minimum and bent away from this again in the region of the hindfoot section (C) in a waisted shape.

4. One-piece spring plate (32) according to one of the preceding claims, wherein the connection bar (324) runs approximately perpendicular to the longitudinal axis (L) between fork gap (322) and lower central recess (323).

5. One-piece spring plate (32) according to claim 4, wherein the width (e) of the connection bar (324) should be between 10 mm and 30 mm for all sizes of spring plates (32), preferably between 12 mm and 22 mm for average shoe sizes.

6. One-piece spring plate (32) according to one of the preceding claims, wherein the central recess (323) in the midfoot section (B) and (C) of the spring plate (32) has a maximum length (f) between 100mm and 220mm and a maximum width (g) between30mm and 70mm, wherein all side walls are curved without sharp edges.

7. One-piece spring plate (32) according to one of the preceding claims, wherein all strands (320, 321) and the connection bar (322) are comprising the same carbon fibre matrix composite material and / or aromatic polyamide fibre matrix composite material and / or glass fibre matrix composite material, to achieve the desired stiffness.

8. One-piece spring plate (32) according to one of the preceding claims, wherein the constant thickness of all spring plate (32) components is between one and three millimeters, most preferred 1 mm.

9. Shoe (10), comprising an upper (20), a midsole (31) and an outsole (40), characterized by that between midsole (31) and outsole (40) is arranged a one-piece spring plate (32) according to one of the preceding claims and the outsole (40) has a suspension structure comprising at least one suspension bracket (41) each equipped with at least one ground support surface (42) arranged along the outline of the midsole (31), providing a multiple of free spaces (43).

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