Outsole for footwear

Abstract

The present invention relates to an outsole (1) for footwear, comprising a heel portion (A), a central portion (B) and a forefoot portion (C). The outsole (1) further comprises a reaction plate (2) extending from the heel portion (A) towards the forefoot portion (C), occupying a central portion (B) of the outsole (1). According to the invention, the reaction plate (2) has a rear section (4) arranged near the upper surface (10) of the heel portion (A) and a front section (6) arranged near the lower surface (12) of the forefoot portion (C). Furthermore, the reaction plate (2) comprises an intermediate section (8) between the rear section (4) and the front section (6), which intermediate section is shaped in the form of an inverted Z or S.

Description

Technical Field

[0001] The present invention relates to an outsole for footwear, and more particularly to an outsole for sports footwear that is capable of storing a portion of the energy associated with an impact on the outsole during walking or running movements and releasing the energy to the user in a uniform manner without hindering the user's movements.

[0002] More specifically, the present invention relates to outsoles for footwear that are capable of reducing a user's energy expenditure and improving his / her running economy, ie, reducing the user's oxygen consumption at a given speed. Background Art

[0003] Running economy is a particularly useful parameter for assessing athlete performance because if one athlete consumes more oxygen than another for the same speed, his / her performance may be worse.

[0004] Outsoles for footwear are known which have attempted to address these problems.

[0005] In particular, outsoles are known which are provided with a reactive plate made of carbon fibers inserted into a midsole, "midsole" being understood as that part of the outsole which is situated between the upper and the tread and which may be formed in one piece with said tread. The function of this plate is to store part of the energy generated when the foot contacts the ground and to release this energy during the push-off phase when the foot leaves the ground.

[0006] Typically, the reaction plate is arched and extends from the heel area to the forefoot area occupied by the toes.

[0007] Examples of outsoles provided with such plates are described, for example, in US 5,052,130 and WO 2016 / 179265.

[0008] While widely appreciated, these solutions are not without their flaws.

[0009] In fact, the reactive plate allows only a minimum portion of the kinetic energy generated during a walking or running movement to be recovered, since the material from which the midsole is made actually tends to absorb part of the energy generated. Summary of the invention

[0010] Therefore, the object of the present invention is to at least partially overcome the above mentioned disadvantages with respect to the prior art.

[0011] In particular, a first object of the present invention is to provide an outer sole for footwear that facilitates the walking or running movements of the user.

[0012] Another object of the present invention is to provide an outer sole for footwear which is able to release a greater amount of kinetic energy generated during a walking or running movement to the lower limb than known solutions.

[0013] Furthermore, it is an object of the present invention to provide an outer sole for footwear which is able to provide suitable support for the foot during walking or running movements without affecting the comfort that must be ensured for the user.

[0014] The above-mentioned objects and tasks are achieved by an outer sole for footwear as claimed in claim 1 . BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Characteristic features and further advantages of the invention will emerge from the following description of some examples of embodiments provided by way of non-limiting example with reference to the accompanying drawings, in which:

[0016] - Figure 1 schematically shows a side view of an outsole for footwear according to the present invention;

[0017] - Figure 2 Schematically shows the Figure 1 a bottom plan view of an outer sole;

[0018] - Figure 3 Schematically shows the Figure 2 A cross section along line III-III;

[0019] - Figure 3A Shown on a larger scale Figure 3 A view of the detail indicated by the letter W;

[0020] - Figure 4 Schematic diagram showing the reaction plate relative to Figure 3 Positioning of the inner template of the outer sole shown;

[0021] - Figure 5 , 7 and 9 is the same as Figure 3 Similar figures, but relating to different embodiments of the outsole according to the invention;

[0022] - Figure 6 , 8 and 10 is the same as Figure 4 Similar diagrams, but involving Figure 5 , 7 And 9. embodiments of the outsole.

[0023] - Fig.11 , 13 , 15 and 17 show the Figure 3 , 5 , 7 and 9, corresponding side views of the reaction plates of the outer soles;

[0024] - Fig.12 , 14 , 16 and 18 show the Fig.11 , 13 , 15 and 17 are corresponding top plan views of the reaction plates;

[0025] - Figure 19-22 showing respective perspective views of further embodiments of a reaction plate according to the present invention;

[0026] - Figure 23-25 Schematically shows Fig.15 of the reaction plates, but in three different operating configurations. DETAILED DESCRIPTION

[0027] The present invention relates to an outsole 1 for footwear, preferably sports shoes, more preferably running shoes. However, as will become clear from the following description, the outsole of the present invention can also be advantageously applied to walking shoes or safety shoes.

[0028] In the remainder of this description of the outsole 1 and its individual components, "front" will be used to identify the portion of the outsole or its individual components that is relatively closer to the toe during use, while "rear" will be used to identify the portion of the outsole or its individual components that is relatively closer to the heel during use.

[0029] Similarly, "upper" will be used to identify the portion of the outsole or individual components thereof that is further from the ground during use, while "lower" will be used to identify the portion of the outsole or individual components thereof that is closer to the ground during use.

[0030] As shown in the drawings, the outsole 1 includes a heel portion A, a central portion B, and a forefoot or toe portion C. The heel portion A of the outsole 1 is a portion on which the heel or rear foot rests, the central portion B of the outsole 1 is a portion on which the arch or midfoot rests, and the forefoot or toe portion C of the outsole 1 is a portion on which the forefoot rests.

[0031] According to the invention, the outsole 1 further comprises a reaction plate 2, wherein the reaction plate is understood to mean a plate made of a material having elastic properties which allow the reaction plate to follow the movements of the user's foot during walking or running movements.

[0032] As will be explained in detail below, the reaction plate 2 can be elastically deformed during the user's walking or running motion, thereby accumulating elastic energy which is released back to the user's heel or forefoot during the same walking or running motion depending on the walking or running phase.

[0033] For example Figure 1 As shown, the reaction plate 2 extends from the heel portion A toward the forefoot portion C, occupying the central portion B of the outsole 1 .

[0034] According to the present invention, the reaction plate 2 has a rear section 4 arranged near the upper surface 10 of the heel portion A and a front section 6 arranged near the lower surface 12 of the forefoot portion C (see Figure 3 , 5 , 7 and 9).

[0035] Preferably, the rear section 4 of the reaction plate 2 is located at a distance of no more than 10 mm from the upper surface 10 of the heel portion A of the outer sole 1 .

[0036] In a preferred embodiment, the rear section 4 of the reaction plate 2 is located no more than 5 mm from the upper surface 10 of the heel portion A of the outer sole 1 .

[0037] The front section 6 of the reaction plate 2 is then preferably located no more than 10 mm from the lower surface 12 of the forefoot portion C of the outsole 1, wherein "lower surface 12" of the forefoot portion C is understood to mean the surface intended to come into contact with the ground.

[0038] In a preferred embodiment, the front section 6 of the reaction plate 2 is located no more than 8 mm from the lower surface 12 of the forefoot portion C of the outsole 1 .

[0039] According to the invention, the reaction plate 2 further comprises a middle section 8 between the rear section 4 and the front section 6, which is shaped in the form of an inverted Z or S. For simplicity, reference will be made to the Z-shaped form below.

[0040] As will become clear from the description that follows, the specific shape of the reaction plate, combined with its specific positioning within the outsole, results in the creation of an outsole that is not only able to transmit back a portion of the energy generated by the impact of the outsole with the ground during a walking or running movement, but is also able to release this portion of energy during separation of the foot from the ground at the appropriate moment and in the correct area (in the heel or forefoot area, depending on the walking or running phase).

[0041] refer to Figure 3A The middle section 8 of the reaction plate 2 comprises an upper portion 16, a lower portion 18 and a central portion 20. Advantageously, the upper portion 16 is connected to the rear section 4, the lower portion 18 is connected to the front section 6, and the central portion 20 extends diagonally between the upper portion 16 and the lower portion 18.

[0042] Preferably, the connection radius R1 between the upper portion 16 and the central portion 20 of the plate 2 is substantially the same as or only slightly different from the connection radius R2 between the central portion 20 and the lower portion 18 of the plate 2 .

[0043] Alternatively, the connection radius R2 between the central portion 20 and the lower portion 18 is greater than the connection radius R1 between the upper portion 16 and the central portion 20 .

[0044] like Figure 3AThe details are shown in Figure 3 and 7 As can be clearly seen in FIG. 1 , the lower portion 18 of the middle section 8 of the reaction plate 2 is preferably positioned adjacent to the lower surface of the outsole 1 .

[0045] Advantageously, the middle section 8 of the plate 2 can be arranged in the central portion B of the outsole 1 (see Figure 1-6 ).

[0046] Alternatively, the middle section 8 of the plate 2 may be arranged in the forefoot portion C of the outsole 1 (see Figure 7-10 ). Advantageously, in this embodiment, the intermediate section 8 can be arranged in a region 11 of the forefoot portion C, which is intended to act as a support for the metatarsal heads of the user's foot.

[0047] This area is located at a distance from the rear end of the outsole equal to about 2 / 3 of the total length of the outsole.

[0048] exist Figure 8 and Fig.10 , the region 11 is schematically shown as being defined by two curved lines 11A and 11B, which take into account the fact that the distance between the metatarsal heads and the rear end of the heel varies depending on the size of the foot of different individuals.

[0049] For example, in the case of a male foot size 42 measured using the French system, the head of the first metatarsal is typically located between 185mm and 202mm from the back of the heel, while in the case of a female foot size 38 measured using the French system, the head of the first metatarsal is typically located between 143mm and 160mm from the back of the heel.

[0050] Similar considerations apply to the other metatarsal heads that are closer to the posterior end of the heel than the head of the first metatarsal (the second, third, fourth, and fifth metatarsal).

[0051] Advantageously, if Fig.12 , 14 , 16 and 18, the middle section 8 of the plate 2 has a width measured along the toe-to-heel axis J of the plate 2, which substantially corresponds to the width of the upper portion 16 of the middle region 8. In particular, the width is between 1.0 and 3.5 cm, preferably between 2.0 and 2.5 cm.

[0052] Reference again Fig.12 , 14 , 16 and 18 , preferably, the middle section 8 of the plate 2 is oriented perpendicular to the axis J.

[0053] refer to Fig.11 , 13, 15 and 17, the rear section 4 of the reaction plate 2 can be substantially flat, while the front section 6 of the reaction plate 2 preferably has an arcuate profile with its concave surface facing upward.

[0054] refer to Figure 4 , 6 , 8 and 10, the peripheral contour of the reaction plate 2 substantially follows the contour 14 of the inner template of the outer sole 1, and the spacing amount b from the contour 14 is preferably between 0.5 and 2.0 cm.

[0055] In some embodiments, the perimeter contour of the reaction plate 2 may be spaced a greater amount relative to the contour of the inner template at certain points. For example, this amount may be increased in the toe area of ​​the outsole, or depending on the configuration of the shoe.

[0056] Reference now Figure 19-22 , wherein for a simpler explanation, a reaction plate 2 having a linear outer contour is shown. However, the following discussion also applies when the outer contour of the plate is shaped as described above (see, for example, Fig.12 , 14 , 16 and 18).

[0057] Fig. 20 and 22 A reaction plate 2 is shown which is provided with a central opening or eyelet 32 ​​which is arranged in the middle section 8 of the plate 2 and extends towards the rear section 4 and towards the front section 6 .

[0058] The provision of the openings 32 advantageously results in different reactions of the plate on the medial and lateral sides of the outsole. Specifically, during the running phase, the openings 32 have the effect of making the plate 2 react differently on the medial and lateral sides to the compressive forces acting thereon, thereby following the natural development of the ankle spiral of the foot.

[0059] Preferably, the reaction plate 2 has a constant thickness between 1.8 mm and 2.5 mm.

[0060] Advantageously, the reaction plate 2 is made of a technopolymer. Preferably, the plate 2 is made using a technopolymer having a matrix based on polyamide or polyether block amide (PEBA), reinforced with carbon or glass fibers.

[0061] refer to Figure 1 , 2 , 3, 3A, 5, 7 and 9, the outsole 1 preferably includes a midsole 22 and a tread 24. The tread 24 is the portion of the outsole that is intended to come into contact with the ground, while the midsole 22 is the portion of the outsole that is located between the upper of the shoe (to which the outsole 1 is applied) and the tread 24.

[0062] The tread 24 is applied to the lower surface 23 of the midsole 32 .

[0063] A tread 24 may be applied to midsole 22 to cover the entire lower surface 23, optionally with lugs extending along the heel and toe.

[0064] Alternatively, the tread 24 may be arranged along the heel portion A and the forefoot portion C, leaving the central portion B of the outsole 1 uncovered.

[0065] In this case, corresponding openings 34 may be arranged in the central portion of the midsole 22 and / or in the forefoot portion of the tread 24. Advantageously, the reaction plate 2 may be visible from the outside of the outsole through these openings (see Figure 2 ).

[0066] The presence of openings 34 also allows the overall weight of outsole 1 to be reduced.

[0067] Advantageously, thanks to the arrangement of the plate 2 in the central portion B of the outer sole 1 , it is possible to dispense with the inclusion of a reinforcing shank in the midsole. In fact, this function is already performed by the plate 2 .

[0068] Preferably, the midsole 22 comprises an upper element 26 and a lower element 28 which are separated from each other. As shown in the figures, the reaction plate 2 is interposed between the upper element 26 and the lower element 28. In this embodiment, once the outsole is applied to the upper of the shoe, both the upper element 26 and the lower element 28 can be seen from the side. The plate 2 is in turn sandwiched between these elements 26, 28 which are glued together.

[0069] Advantageously, a seat 30 suitable for housing the reaction plate 2 and the upper element 26 may be arranged in the lower element 28 of the midsole 22 .

[0070] Preferably, the seat 30 is arranged in the lower element 28 so that once inserted into the seat 30 , the upper element 26 is flush with the upper surface of the lower element 28 .

[0071] In this embodiment, once the outer sole 1 is applied to the upper of the shoe, the upper element 26 is not visible from the side. Only the lower element 28 is visible.

[0072] Preferably, the upper element 26 and the lower element 28 of the midsole 22 are made of expanded polymer material. Advantageously, the lower element 28, which is arranged substantially between the tread 24 and the reaction plate 2, and the upper element 26, which is arranged between the user's foot and the reaction plate 2 during use, can both be made of a material with high elasticity, such as ethylene vinyl acetate (EVA), which is able to transfer back most of the impact energy received during running or walking movements. Advantageously, ethylene vinyl acetate (EVA) can be combined with expanded polyether block amide (PEBA) in order to obtain a greater rebound effect.

[0073] To this end, ethylene vinyl acetate (EVA) may advantageously have nitrogen added to it before being loaded into the mold to improve its elasticity and reduce its density.

[0074] Alternatively, two different materials or the same material but with different properties (eg, different hardness) may be used for the lower element 28 and the upper element 26 .

[0075] As shown in the drawings, the middle section 8 of the plate 2 may be received within a gap 36 formed between the upper element 26 and the lower element 28 of the midsole 22 to facilitate molding and assembly of the outsole.

[0076] The tread 24 may be made of a polymer material such as TPU, TPR or vulcanized rubber.

[0077] Advantageously, the thickness of the midsole 22 (whether formed by a single element or by two separate elements) is substantially constant along the heel portion A and the forefoot portion C. This thickness may be between 3 and 5 cm.

[0078] Preferably, the heel portion A is thicker than the forefoot portion C.

[0079] Advantageously, the difference between the thickness of the midsole along the heel portion A and the thickness along the forefoot portion C (known in technical terms as the "drop") is not greater than 5 mm.

[0080] In turn, the thickness of the tread 24 is preferably between 3 and 5 mm.

[0081] The above drop value advantageously allows the user's foot to rest on the ground in the arch area, which is beneficial for the push-off action of the foot when running.

[0082] Furthermore, by using a smaller drop value, combined with a forefoot midsole thickness of approximately 4 cm, the amount of energy that can be transferred back to the user's foot will be greater due to the arrangement of the middle section 8 of the plate 2.

[0083] refer to Figures 23 to 25 , the following will combine Figure 7 , 15 The working principle of the reaction plate 2 of the outer sole according to the present invention is briefly described by the embodiment of the plate 2 shown in Figures 1 and 16.

[0084] However, the following discussion also applies to the other embodiments shown in the figures.

[0085] In a manner known per se, the timing of the running movement can be comprised between two consecutive contact moments of the heel of the same foot and is formed by a so-called "stance phase" and a swing phase, wherein the "stance phase" accounts for about 60% of the entire cycle and the swing phase accounts for about 40% of the entire cycle.

[0086] The standing phase includes:

[0087] - The landing phase, in which the heel makes contact with the support surface;

[0088] -Stand phase, in which the entire plantar area is in contact with the support surface;

[0089] -The push-off phase, in which the toes remain in contact with the support surface while the heel lifts off the ground.

[0090] The swing phase instead occurs between the lifting of the toes from the ground and the subsequent landing of the heel of the same foot.

[0091] Figure 23-25 Schematic diagram showing the foot stance phase ( Fig.23 ) and the push-off phase ( Fig.24 and 25 ) during the three periods.

[0092] During the stance phase, when the forefoot portion of the outsole strikes the ground (this impact is schematically represented by the arrow Fg), the middle section 8 of the plate is subjected to a compression Fz which allows part of the impact energy to be stored.

[0093] The Z-shaped form of the intermediate section 8 has in fact the effect that, due to the flexing movement of the central portion 20 , the upper portion 16 can be moved closer towards the lower portion 18 , storing a corresponding amount of elastic energy.

[0094] Since the midsole (especially the upper element) is made of a material with high elasticity, the compression of the middle section 8 is promoted. This material facilitates the compression of the middle section 8 of the plate 2 on the one hand, and ensures that the user's foot does not feel any discomfort due to the presence of the Z-shaped middle section on the other hand.

[0095] At the same time, due to the specific Z-shaped configuration of the middle section, the force Fz generates a moment Mz, which applies an upward thrust to the rear section 4 of the plate 2, which is conducive to the separation of the heel portion A of the outsole 1 from the ground G.

[0096] During the next phase (see Fig.24 ), the heel portion A of the outsole 1 is separated from the ground, and the contact point C between the forefoot portion of the outsole and the ground moves toward the toe end as the forefoot portion swings.

[0097] Therefore, since the front section 6 of the plate 2 has a concave profile, the force Ftrans acting on the plate 2 generates a moment Mtrans, which, even if its intensity is smaller than the moment Mz, will continue to generate an upward thrust along the rear section 4 of the plate, thereby promoting the separation of the heel portion A of the outsole 1 from the ground G.

[0098] During this phase there will also be an initial release of the elastic energy stored in the middle section 8 of the plate 2 .

[0099] Finally, during the next phase (see Fig.25 ), the contact point C between the outsole and the ground moves further toward the toe end of the outsole.

[0100] During this phase (which corresponds to the push-off phase, the so-called rolling phase), the force Ft-t acting on the plate 2 moves further toward the toe end of the foot. This force Ft-t also generates a moment Mt-t acting on the rear section 4 of the plate 2, thereby providing a further upward thrust along the heel portion A of the outsole 1.

[0101] The concave profile of the front section 6 of the plate 2 arranged near the lower surface of the outsole together with the Z-shaped form of the middle section 8 causes a so-called "teeter-totter effect" to occur, which facilitates separation of the toes during the push-off phase.

[0102] Furthermore, the push-off phase is also facilitated by the complete release of the elastic energy stored in the middle section 8 of the plate 2 during the first few phases.

[0103] This way, the running motion is facilitated without compromising comfort.

[0104] At this point, it is clear that a Z-shaped middle section is provided on the inner side of the outsole of the reaction plate 2, and the middle section is arranged near the upper surface of the outsole along the heel portion and near the lower surface of the outsole along the forefoot portion, so as to maximize the release of the energy stored by the outsole during the running movement.

[0105] In particular, the Z-shaped form of the middle section facilitates flexion of the reaction plate, making the shoe less rigid and facilitating storage of more energy in the middle section, thereby maximizing the transfer of this energy to the user's heel through the resulting "see-saw" effect.

[0106] A person skilled in the art may modify the embodiments of the outsole in order to meet specific needs and / or replace the described elements with equivalent ones, without departing from the scope of the appended claims.

Claims

1. An outer sole (1) for footwear, the outer sole comprising a heel portion (A), a central portion (B) and a forefoot portion (C), the outer sole (1) further comprising a reaction plate (2) extending from the heel portion (A) towards the forefoot portion (C) and occupying the central portion (B) of the outer sole (1); The outer sole (1) is characterized in that the reaction plate (2) has a rear section (4) arranged near the upper surface (10) of the heel portion (A) and a front section (6) arranged near the lower surface (12) of the forefoot portion (C), and the reaction plate (2) includes a middle section (8) located between the rear section (4) and the front section (6), and the middle section is shaped in the form of an inverted Z or S.

2. The outsole (1) according to claim 1, characterized in that The middle section (8) comprises an upper portion (16), a lower portion (18) and a central portion (20); the upper portion (16) is connected to the rear section (4), the lower portion (18) is connected to the front section (6), and the central portion (20) extends diagonally between the upper portion (16) and the lower portion (18) of the middle section (8).

3. The outsole (1) according to claim 2, characterized in that The lower portion (18) of the middle section (8) of the reaction plate (2) is located near the lower surface of the outer bottom (1).

4. Outsole (1) according to any one of the preceding claims, characterized in that The intermediate section (8) is arranged in a central portion (B) of the outer sole (1).

5. The outsole (1) according to any one of claims 1 to 3, characterized in that: The middle section (8) is arranged in the forefoot portion (C) of the outer sole (1).

6. An outsole according to any one of the preceding claims, characterized in that The rear section (4) of the reaction plate (2) is substantially flat, and the front section (6) of the reaction plate (2) has an arched profile with the concave surface of the arched profile facing upwards.

7. Outsole (1) according to any one of the preceding claims, characterized in that The outsole comprises a midsole (22) and a tread (24); the tread (24) is applied to the lower surface (23) of the midsole (22).

8. The outsole (1) according to claim 7, characterized in that The midsole (22) includes an upper element (26) and a lower element (28); the upper element (26) and the lower element (28) are separated from each other, and the reaction plate (2) is interposed between the upper element (26) and the lower element (28).

9. Outsole (1) according to the preceding claim, characterized in that A seat (30) suitable for accommodating the reaction plate (2) and the upper element (26) is arranged in the lower element (28).

10. The outsole (1) according to claim 7, characterized in that The tread (24) is arranged along the heel portion (A) and the forefoot portion (C) of the outer sole (1), so that the central portion (B) of the outer sole is not covered; an opening (34) is arranged in the central portion of the midsole (22) and / or the forefoot portion of the tread (24), through which the reaction plate (2) can be seen from the outside of the outer sole.

11. Outsole (1) according to any one of the preceding claims, characterized in that The reaction plate (2) is provided with a central opening (32), which is arranged in a middle section (8) of the reaction plate (2) and extends towards a rear section (4) of the plate (2) and towards a front section (6) of the plate (2).

12. Outsole (1) according to any one of the preceding claims, characterized in that The middle section (8) of the reaction plate (2) has a width measured along the toe to heel axis (J) of between 1.0 and 3.5 cm.

13. Outsole (1) according to any one of the preceding claims, characterized in that The middle section (8) of the reaction plate (2) is oriented perpendicular to the toe-to-heel axis (J).

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