Sole for professional footwear, mold for its manufacture, professional footwear, and manufacturing method for the sole

Abstract

The invention relates to a sole (S) for professional footwear (C) comprising a lower sole (1) and a lateral sole (2), characterised in that an insert piece (4) is located inside the sole (S), extending along a surface covering between 60% and 95% of the total surface area of the lower sole (1), where said insert piece (4) comprises a first rear section (4.3) made of a first material, and a second front section (4.4) made of a second material, which is different from the first material. The invention also relates to professional footwear (C) comprising said sole (S), a mold for manufacturing said sole (S), and the method for manufacturing said sole (S).

Description

[0001] SOLE FOR PROFESSIONAL FOOTWEAR AND MOLD FOR ITS MANUFACTURE

[0002] DESCRIPTION

[0003] OBJECT OF THE INVENTION

[0004] The present invention relates to the technical field of the footwear industry and, in particular, to a new sole for professional footwear, as well as the mold for its manufacture. The invention also includes the method for obtaining the sole, as well as the professional footwear itself that incorporates it.

[0005] BACKGROUND OF THE INVENTION

[0006] Professional footwear is footwear that must be able to offer an adequate feeling of comfort and convenience, given that this type of footwear is intended to be used by workers for long periods of time.

[0007] Among professional footwear, safety footwear is a type of shoe that incorporates additional features to protect the user from risks that could lead to accidents. Thus, it is equipped with a safety toe cap to protect the front of the foot and is designed to offer adequate protection to users in case of an accident.

[0008] Currently, it is possible to find in the state of the art various designs of safety footwear that, in addition to protecting users, are able to offer an adequate feeling of comfort and convenience, as required by professional footwear.

[0009] For example, patent ES2923007 describes an energizing safety shoe comprising a safety toecap and a layered sole consisting of a lower layer, an intermediate layer and an upper layer, where the intermediate layer incorporates an elastic insert, located exclusively in the rear area of ​​the shoe, which makes the support of the foot on the ground more comfortable when walking.

[0010] Thus, in the state of the art it is possible to find different solutions to improve the cushioning or gait of the user, although all of them focus essentially on the use of inserts of different materials, usually of an elastomeric nature, but always intended to protect the heel part, neglecting the plantar or front part of the foot.

[0011] The present invention addresses the shortcomings of currently available soles for professional footwear, offering a superior advantage beyond the typically reinforced protection in the heel area. Thus, in addition to the protection and safety this type of footwear provides, it offers significantly better gait than current footwear, improving cushioning not only in the heel area but also in the forefoot, where a propulsive effect is also achieved. It is, therefore, footwear that biomechanically improves the user's gait. As described above, the invention is not limited to the use of the sole in safety footwear and can therefore be used in any type of professional footwear.

[0012] DESCRIPTION OF THE INVENTION

[0013] A first object of the invention is a sole (S) for professional footwear (C) comprising a lower sole (1) and a side sole (2), located essentially transversely to the lower sole (1), wherein said lower sole (1) comprises a first external face (1.1) and a second internal face (1.2), wherein said second internal face (1.2) is located within a cavity whose base is the lower sole (1) and whose side wall is the side sole (2), wherein said side sole (2) comprises a first front end (2.1) located in a front section or toe of the sole (S), a second rear end (2.2) located in a rear section or heel of the sole (S), a first external side face (2.3) and a second internal side face (2.4), opposite the first external side face (2.3), wherein said first external side face (2.3) and second internal side face (2.4) are located within a cavity whose base is the lower sole (1) and whose side wall is the side sole (2).4) extend from the heel to the toe and comprise at least one window (3, 3'), where said sole (S) is characterized in that inside the cavity there is located an insert piece (4) comprising a first upper face (4.1) and a second lower face (4.2), parallel and opposite to each other, where said second lower face (4.2) rests on the second inner face (1.2) of the lower sole (1) and where said insert piece (4) extends along a surface that covers between 60% and 95% of the total surface of the lower sole (1) and comprises a first rear section (4.3) made of a first material, and a second front section (4.4) consisting of a second material, different from the first material, where said first material and second material are selected independently from a group consisting preferably of polyurethane, expanded or cellular polyurethane, expanded rubber, expanded thermoplastic polyurethane (TPU) and EVA (ethylene vinyl acetate), and where said first rear section (4.3) and said second front section (4.4) are joined together by a joining surface (4.5) preferably located at the shank of the professional footwear (C).

[0014] For the purposes of this patent, professional footwear or work footwear is understood to be footwear suitable for the performance of a profession. In a particular embodiment of the invention, the professional footwear (C) will be safety footwear, which is characterized by comprising protective elements, such as a safety toecap. However, the invention is not limited to this type of safety footwear and may be used in any professional footwear, including industrial footwear, footwear for healthcare personnel, police officers, etc.

[0015] The invention also includes professional footwear (C) comprising a sole (S) as claimed.

[0016] The invention also relates to a mold for manufacturing the sole (S) for professional footwear (C), as claimed. This mold comprises a piston (7) and a ring (8), where the ring (8) consists of two complementary pieces, although for simplicity, only one of them is shown in the figures. The two pieces of the ring (8) are designed to fit together during the manufacturing process of the sole (S), embracing the piston (7), which is positioned between the two pieces of the ring (8).

[0017] Additionally, the invention relates to the manufacturing process of the claimed sole (S), which comprises: a) injecting a constituent material of the lower sole (1), preferably selected from polyvinyl chloride (PVC), polyurethane (PL1), rubber and thermoplastic polyurethane (TPU), in a molten state, through a second injection channel consisting of a second concave groove (10) of the ring (8), onto the surface of the plunger (7) and allowing said material to cure for a time, preferably from 1 to 3.5 minutes, after which time, once the constituent material of the lower sole (1) has cured, the excess material that may remain located in the groove (11) of the plunger (7) is removed; b) placing the insert piece (4) on the second inner face (1).2) of the lower sole (1) and inject a constituent material of the lateral sole (2), in a molten state, through a first concave slit (9) of the ring (8), circulating or flowing through the first slit (11) of the plunger (7) and allow said injected material to cure for a time, preferably from 1.5 to 5 minutes, after which it solidifies, giving rise to the sole (S) that houses the inserted piece (4) inside.

[0018] BRIEF DESCRIPTION OF THE FIGURES

[0019] To complete the description of the invention and to aid in a better understanding of its characteristics, this description is accompanied by a set of figures in which, for illustrative and non-limiting purposes, the following has been represented:

[0020] Figure 1 represents a perspective view of a professional footwear (C) comprising a sole (S) according to a particular embodiment of the present invention.

[0021] Figure 2 represents an exploded perspective view of the elements of professional footwear (C), according to the particular embodiment shown in Figure 1.

[0022] Figure 3 represents a detailed perspective view of a particular embodiment of the inserted part (4) of the invention.

[0023] Figure 4 represents a perspective view of the piston (7) and ring (8) corresponding to a particular embodiment of the invention.

[0024] Figure 5 represents a partial perspective view of one of the embodiments of the ring (8) that is the subject of the invention.

[0025] List of references shown in the figures:

[0026] S. Sole

[0027] C. Professional footwear

[0028] 1. Bottom sole

[0029] 1.1 First outer side of the lower sole

[0030] 1.2 Second inner side of the lower sole

[0031] 2. Lateral sole

[0032] 2.1 First front end of the lateral sole

[0033] 2.2 Second rear end of the lateral sole 2.3 First external lateral side of the lateral sole

[0034] 2.4 Second inner lateral side of the lateral sole

[0035] 3. 3' Windows

[0036] 4. Insert piece

[0037] 4.1 First top face of the inserted piece

[0038] 4.2 Second lower face of the inserted piece

[0039] 4.3 First rear section of the insert piece

[0040] 4.4 Second front section of the insert piece

[0041] 4.5 Bonding surface

[0042] 4.6 Holes of the inserted part

[0043] 5. Anti-perforation layer

[0044] 6. Safety toe cap

[0045] 7. Piston

[0046] 8. Ring

[0047] 8.1 First rear end of the ring (8)

[0048] 8.2 Second front end of the ring (8)

[0049] 9. First concave groove of the ring (8)

[0050] 9.1 Outlet hole

[0051] 10. Second concave groove of the ring (8)

[0052] 10.1 Deflector relief

[0053] 11. First piston groove (7)

[0054] 12. Gasket, preferably made of Teflon, to prevent material leaks.

[0055] DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

[0056] With the support of the figures accompanying this document, one of the preferred embodiments of the sole (S) that is the subject of the invention, as well as the professional footwear (C) that comprises it, is described in detail.

[0057] Figure 1 shows a perspective view of professional footwear (C) comprising a sole (S) according to a particular embodiment of the present invention. The sole (S) comprises a lateral sole (2), positioned essentially transversely to the lower sole (1), which is designed to make direct contact with the ground or surface on which the professional footwear (C) rests. The lateral sole (2) comprises a first front end (2.1), located in a front section or toe of the sole (S), a second rear end (2.2) located in a rear section or heel of the sole (S), and a first external side face (2.3) extending from the first front end (2.1) to the second rear end (2.2). The second internal side face (2.4) is not shown in the figure, although it is located opposite and parallel to the first external side face (2.3).

[0058] Figure 2 shows an exploded view of the elements of the professional footwear (C), according to the particular embodiment shown in Figure 1. In Figure 2, the lateral sole (2) is visible, which can be positioned essentially or completely perpendicular to the plane corresponding to the lower sole (1). Additionally, the insert (4) is shown, located inside the cavity formed between the lower sole (1), the base of the cavity, and the lateral sole (2), corresponding to the lateral surface of the cavity. It is also shown how this insert (4) rests on the second inner face (1.2) of the lower sole (1) and comprises a first rear section (4.3), made of a first material, and a second front section (4.4), made of a second material, different from the first material, where said first rear section (4.3) and said second front section (4.4) are...4) are joined together by a bonding surface (4.5) preferably located on the shank of the professional footwear (C). As described above, both the first and second materials can be independently selected from a group preferably consisting of polyurethane, expanded or cellular polyurethane, expanded rubber, expanded thermoplastic polyurethane (TPU), and EVA (ethylene-vinyl acetate).

[0059] As described above, the first material is different from the second material, either because they are different materials, but compatible with each other, meaning compatible with each other, or because they are the same material, but with different behavior parameters (initial elongation, tensile strength, deceleration in impact absorption, etc.).

[0060] In a particular embodiment, the first material of the first rear section (4.3) may consist of cellular polyurethane (Pll), with an initial elongation of 175% (measured according to ISO 22654:2002), a tensile strength of 0.94 MPa (measured according to ISO 22654:2002), and an impact absorption deceleration of 103 m / s² 2 (measured according to the INESCOP -4970 A method). In turn, the second material of the second front section (4.4) may consist of cellular polyurethane (PLI), with an initial elongation of 226% (measured according to ISO 22654:2002), a tensile strength of 1.16 MPa (measured according to ISO 22654:2002) and an impact absorption deceleration of 207 m / s² 2 (measured according to the INESCOP -4970 A method).

[0061] As described above, the lower sole (1), as shown in Figure 1 and Figure 2, is designed to make direct contact, via its first outer face (1.1), with the ground or surface on which the professional footwear (C) rests during use. It may be made of any suitable material to ensure that the professional shoe meets the required protection standards for the work environment, and this is not a limitation for the purposes of the present invention. In specific embodiments of the invention, this material may consist of polyvinyl chloride (PVC), polyurethane (PLI), rubber, thermoplastic polyurethane (TPU), among other examples.

[0062] Thus, depending on the type of material selected, the bottom sole (1) can be, among other examples:

[0063] . non-slip, in which case it offers superior traction on slippery surfaces;

[0064] Lightweight and flexible, suitable for jobs requiring mobility and agility; and / or

[0065] Resistant to chemicals and high temperatures, suitable for specific industries that work under these conditions.

[0066] Figure 3 shows a detailed view of the inserted piece (4) seen in Figure 2, where in addition to the first rear section (4.3) and the second front section (4.4), as well as the joining surface (4.5), the first upper face (4.1) and a second lower face (4.2), parallel and opposite to each other, are shown, which also constitute the inserted piece (4).

[0067] Figures 1 and 2 show how the first external side face (2.3) and second internal side face (2.4) of the lateral sole (2) extend from the heel to the toe. Also visible on the first external side face (2.3) are a plurality of windows (3, 3'), located in both the rear and front sections of the sole (S). These windows are also located, oppositely and symmetrically, on the second internal side face (2.4). Through these windows (3, 3'), the insert (4), located inside the sole (S), is visible. The function of these windows (3, 3') in the sole (S) is to allow the insert (4) to deform outwards when subjected to the pressure exerted by the wearer's weight.This facilitates the release of energy from the inserted piece (4) and improves the cushioning and propulsion of the foot strike, depending on whether it acts on the rear or front area of ​​the sole (S).

[0068] Preferably, the first rear section (4.3) extends from an initial end corresponding to the second rear end (2.2) of the lateral sole (2) to a final end, covering up to 30% of the total surface area of ​​the lower sole (1), and the second front section (4.4) extends from the final end of the first section (4.3) to reach 95% of the total surface area of ​​the lower sole (1). As described above, both sections are joined to form a single insert (4). The specific joining technique between the first rear section (4.3) and the second front section (4.4) is not limiting to the invention and may consist of any suitable technique, such as injection molding, adhesives, etc.

[0069] In a preferred embodiment of the invention, as shown in Figure 3, the first rear section (4.3) of the insert piece (4) will be located in the rear section or heel of the sole (S) and the second front section (4.4) of the insert piece (4) will be located in the front section or toe of the sole (S), where the rear section of the sole (S) extends from the second rear end (2.2) to a position where the shank of the professional footwear (C) will be located and the front section of the sole (S) extends from said position to the first front end (2.1).

[0070] The configuration of the insert (4) in two sections, a first rear section (4.3) made of a first material and a second front section (4.4) made of a second material, different from the first material, is one of the distinctive technical features of the invention. In this way, the claimed insert (4) offers the advantage of providing distinct technical effects, in particular, different biomechanical characteristics, in the first rear section (4.3) and in the second front section (4.4). Thus, on the one hand, it provides a cushioning effect in the rear section or heel of the sole (S), where the first rear section (4.3) is located.3) of the insert (4), which translates into a notable reduction in physical problems for the user, such as plantar fasciitis, joint pain, ankle overload, periostitis, among others, during prolonged or physically demanding work periods, and a synergistic, cushioning, and propelling effect on the foot strike in the front or toe section of the sole (S), where the second front section (4.4) of the insert (4) is located, coinciding with the phalangeal area, achieving significant improvements in gait mechanics. Thus, professional footwear (C) using the claimed sole (S) will have the advantage, compared to other footwear in the prior art, of being a shoe that biomechanically improves the user's gait, is very comfortable, and suitable for adapting to each phase of the gait.The biomechanical properties of the claimed sole (S) have been shown to be extremely durable, remaining unchanged for virtually the entire lifespan of the footwear.

[0071] Furthermore, the claimed sole (S) offers the additional advantage of allowing more precise adaptation of professional footwear (C) to the user's foot type, whether pronating, supinating or normal.

[0072] Furthermore, in a further preferred embodiment of the invention, as shown in Figure 2 and Figure 3, the inserted piece (4) may comprise along the surface corresponding to the first upper face (4.1) a plurality of holes (4.6) that may penetrate the inserted piece (4) to a depth that may be variable, not being limiting for the object of the invention.

[0073] In turn, the height or distance between the first upper face (4.1) and the second lower face (4.2) of the inserted piece (4) may vary between 5 and 30 mm, in any case being adequate to support the weight of the user of the professional footwear (C) where the professional sole (S) is located, during its use. Likewise, the height (H) of the lateral sole (2), as shown in Figure 2, is not a limiting technical characteristic for the object of the invention.

[0074] As described above, the invention also includes professional footwear (C) comprising a sole (S) as claimed.

[0075] In a preferred embodiment of the invention, as shown in Figure 2, said professional footwear (C) may comprise an anti-perforation layer (5) parallel to the lower sole (1), located in direct contact with the first upper surface (4.1) of the insert (4). Said anti-perforation layer (5) may be made of a material suitable for ensuring the desired level of protection, such as, for example, a metal, resin, aramid fibers (Kevlar®), etc.

[0076] In a further particular embodiment of the invention in which the footwear is a safety shoe, said professional footwear (C) shall further comprise a safety toecap (6) located in direct contact with the front section of the sole (S), as well as a textile or fabric attached to the sole by gluing, molding, or any other technique intended for this purpose.

[0077] Additionally, Figures 4 and 5 show a particular embodiment of the mold for manufacturing the sole (S) for professional footwear (C) as claimed. This mold comprises a plunger (7) and a ring (8), where the ring (8) consists of two complementary pieces, although for simplicity, only one of them is shown in the figures. The two pieces of the ring (8) are designed to fit together during the manufacturing process of the sole (S), embracing the plunger (7), which is positioned between the two pieces of the ring (8).

[0078] Each ring piece (8) in turn comprises at least a first concave groove (9) and a second concave groove (10), designed to form a first injection channel and a second injection channel, respectively, once the ring (8) is attached to the plunger (7).

[0079] In a preferred embodiment of the invention, a deflector relief (10.1) can be additionally located at the entrance of the second concave groove (10), designed to improve the circulation of the molten material injected during the manufacturing process of the sole (S), which will form the sole once solidified.

[0080] In a further preferred embodiment of the invention, the ring (8) may further comprise at least one outlet hole (9.1), located at the second front end of the ring (8.2), designed to facilitate the outlet of the injected material during the manufacturing process of the sole (S), thus ensuring an adequate distribution of the molten material injected into the mold.

[0081] Additionally, the invention relates to the manufacturing process of the claimed sole (S), as previously described. One of the main challenges of the claimed process is ensuring that the injected material flows properly from the first rear inlet (8.1), corresponding to the heel of the sole (S), to the second front outlet (8.2), corresponding to the toe of the sole (S), without material loss. This challenge has been overcome by injecting the material through two channels: a first injection channel and a second injection channel, formed by the specific design of the plunger (7) and ring (8).

[0082] In a preferred embodiment of the invention, the process may comprise an improvement in the flow of the molten material injected into the mold by injecting it into the second feed channel through a deflector relief (10.1) located at the entrance of the second concave groove (10) of the ring (8).

Claims

CLAIMS 1. A sole (S) for professional footwear (C) comprising a lower sole (1) and a lateral sole (2), located essentially transversely to the lower sole (1), wherein said lower sole (1) comprises a first external face (1.1) and a second internal face (1.2), wherein said second internal face (1.2) is located within a cavity whose base is the lower sole (1) and whose lateral wall is the lateral sole (2), wherein said lateral sole (2) comprises a first front end (2.1) located in a front section or toe of the sole (S), a second rear end (2.2) located in a rear section or heel of the sole (S), a first external lateral face (2.3) and a second internal lateral face (2.4), opposite the first external lateral face (2.3), wherein said first external lateral face (2.3) and second internal lateral face (2.4) extend from the heel to the toe and comprise at least one window (3, 3'), where said sole (S) is characterized in that inside the cavity there is located an insert piece (4) comprising a first upper face (4.1) and a second lower face (4.2), parallel and opposite to each other, where said second lower face (4.2) rests on the second inner face (1.2) of the lower sole (1) and where said insert piece (4) extends along a surface that covers between 60% and 95% of the total surface of the lower sole (1) and comprises a first rear section (4.3) made of a first material, and a second front section (4.4) made of a second material, different from the first material, where said first rear section (4.3) and said second front section (4.4) are joined together by a joining surface (4.5).

2. Sole, according to claim 1, wherein the first material and second material are selected independently from a group consisting of polyurethane, expanded polyurethane, expanded rubber, expanded thermoplastic polyurethane, and ethylene vinyl acetate.

3. Professional footwear (C) characterized in that it comprises a sole (S) according to claim 1 or 2.

4. Professional footwear (C) according to claim 3, wherein said footwear further comprises a safety toecap (6) located in direct contact with the front section of the sole (S).

5. Mold for manufacturing a sole (S) for professional footwear (C) according to claim 1 or 2, characterized in that it comprises a piston (7) and a ring (8), where said ring (8) is made up of two complementary pieces designed to fit together during the manufacturing process of the sole (S), embracing the piston (7), and wherein each ring piece (8) in turn comprises at least a first concave groove (9) and a second concave groove (10), designed to form a first injection channel and a second injection channel, respectively, once the ring is coupled (8) to the piston (7).

6. Mold, according to claim 5, wherein at the entrance of the second concave groove (10) there is a deflector relief (10.1), designed to improve the circulation of the injected molten material during the manufacturing process of the sole (S).

7. Manufacturing process of the sole (S) for professional footwear (C) according to claim 1 or 2 by means of a mold according to claim 5 or 6, characterized in that it comprises: a) injecting a constituent material of the lower sole (1), in a molten state, through a second injection channel consisting of the second concave groove (10) of the ring (8), onto the surface of the plunger (7) and allowing said material to cure; b) placing the insert (4) on the second inner face (1.2) of the lower sole (1) and injecting a constituent material of the lateral sole (2), in a molten state, through a first concave groove (9) of the ring (8), circulating through a first groove (11) of the plunger (7), and allowing said injected material to cure for a time until its solidification, giving rise to the sole (S) that houses the insert (4) inside.

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