FOOTWEAR MIDSOLE, METHOD OF MANUFACTURE AND MOULD FOR THE MANUFACTURE THEREOF

Abstract

A footwear midsole, method of manufacture and mould for the manufacture thereof, which relates to a footwear midsole and a method for the manufacture of a footwear midsole obtained by moulding. The midsole presents a first body with a hollow or recess that determines perimeter walls in said first body with an intermediate filling that extends above the perimeter walls and a third material, acting as a lining, overlaid on the second material. The method uses a special mould which, in addition to a lower part and an upper part, is equipped with an intermediate piece, such that the method presents a casting phase between the aforementioned walls of a filling layer of said second material, preferably polyurethane.

Claims

1. A footwear midsole characterised in that it comprises: a first lower body, made of a first material, which comprises a hollow determined by a perimeter wall, a second material that fills the hollow and extends above the walls of the first body, determining an intermediate layer, and a third material, as a lining of the midsole, overlaid on the second material.

2. The midsole, according to claim 1, characterised in that the second material is polyurethane.

3. The midsole, according to claim 1, characterised in that the first material is a composite material of rubber with cork or polyurethane with cork.

4. A method for manufacturing footwear midsoles, of the type in claim 1, characterised in that it comprises the following steps: a) Inserting a first hollow body with a perimeter wall that has a tab on its periphery that rests on the upper surface of said lower part of the mould in the lower part of a mould, b) positioning an intermediate plate of the mould on said lower part of the mould, resting on the aforementioned tab, and with said intermediate plate comprising a central through opening approximately coinciding with the hollow of the first body, with said opening determining a side wall and a perimeter edge which will determine the upper surface of the midsole, c) arranging at least one lining of a third material on an upper part of the mould, d) casting the second material into the hollow of the first body, e) placing the upper part of the mould with the lining on the intermediate plate, resting the lining on the perimeter edge of the intermediate plate, f) expanding and curing the second material between the inside of the first body mould and the lining, g) opening the upper part of the mould and of the intermediate plate, and h) extracting the midsole from the lower mould.

5. The method, according to claim 4, characterised in that the lining is positioned in step c) in at least two points arranged on the upper part of the mould, which in step e) will be inserted into holes in the intermediate plate.

6. A mould for manufacturing footwear midsoles, according to the method in claim 4, which comprises a lower part, with a recessed space in the shape of the lower part of the footwear midsole to be manufactured and an upper part, characterised in that it further comprises an intermediate plate with a central through opening that determines a side wall and a perimeter edge that is complementary with the upper part and the coupling of which will determine the upper surface of the midsole.

7. The mould, according to claim 6, characterised in that the intermediate plate comprises at least two holes on the perimeter edge and the upper part comprises at least two points, such that when the upper part is placed over the perimeter edge of the intermediate plate, the points fit into the holes of the edge.

Description

DESCRIPTION OF THE DRAWINGS

[0056] As a complement to the description of the present invention, and for the purpose of helping to make the features of the invention more readily understandable, this specification is accompanied by a set of drawings which form an integral part of it and, by way of illustration and not limitation, represent the following:

[0057] FIGS. 1, 2, 3 and 4 show a series of perspective views of an exemplary embodiment of the mould object of the invention to carry out the method for manufacturing the midsole, shown at different steps of said method, showing the main parts and elements that it comprises.

[0058] FIG. 5 shows an upper plan view of an example of the midsole obtained, in its step prior to the trimming of the surplus material around the perimeter.

[0059] FIG. 6 shows a perspective view of an example of the midsole obtained, according to the method of the invention.

[0060] FIGS. 7 and 8 show two perspective views of the respective cross-sections, longitudinal and transversal respectively, of the midsole obtained, according to the invention, showing the parts that make up the midsole and the configuration thereof.

[0061] FIG. 9 shows a perspective view of a footware with the midsole object of the present invention, specifically a sandal.

PREFERRED EMBODIMENT OF THE INVENTION

[0062] In view of the aforementioned figures, an exemplary embodiment of the midsole, mould and method objects of the invention are described below.

[0063] As shown in FIGS. 1 to 4, the mould (1) for manufacturing a footwear midsole (11), according to the method of the invention, comprises a lower part (2), with a recessed space (2a) to tightly incorporate a first body (11) of a first material, preferably rubber with cork, with said first body having a void or hollow, as well as a perimeter tab that overlaps the upper surface of the lower part of the mould.

[0064] The mould further comprises an intermediate plate (4), which is placed on the lower part (2) of the mould and which has a through opening (4a) approximately coinciding with the void or hollow of the first body (11). Likewise, said intermediate plate has a side wall that delimits the through opening (4a) and a perimeter edge (4b) that will determine the shape of the upper surface of the midsole (10). The lower surface of the intermediate plate is located on the perimeter tab of the first body (11) of the midsole (11). In this preferred form, said intermediate plate also has a recess (4c) over the perimeter edge (4b) determined by a second wall on the perimeter of the edge (4b). Alternatively, the intermediate plate may possibly not include the recess (4c) with the wall on its perimeter, i.e., it may be a plate without said second wall that determines the aforementioned recess. The intermediate plate (4) may incorporate slots (7) for the outlet of air or gases.

[0065] The last part of the mould is the upper part (3) of the mould, preferably comprising a protrusion (3a) intended to be inserted into the recess (4c) of the intermediate plate. In addition, the protrusion (3a) of the upper part (3) of the mould (1) has several points (5), or pointed elements, preferably at least two, such that when the upper part (3) of the mould is lowered or placed on the intermediate plate (4), they fit into holes (6) made to coincide with the perimeter edge (4b) of said intermediate plate (4). If the intermediate plate does not have the second side wall, i.e., if it does not have the recess, the upper part of the mould may not incorporate the aforementioned protuberance.

[0066] To use the aforementioned mould (1), the first body (11), preferably of a first material that is rubber with cork, is inserted tightly in the recess (2a) of the lower part (2) of the mould, such that the perimeter tab of said first body rests on the upper surface of the lower part (2) of the mould.

[0067] Next, the intermediate plate (4) is lowered or placed on the lower part (2) of the mould, such that the lower surface of the plate (4) rests on the perimeter tab of the first body (11).

[0068] The lining (13) of the footwear midsole, made of a third material, which may be natural, leather, synthetic, or microfibre, is then placed on the plate (4), covering the central opening (4a) of the plate. The upper part (3) of the mould is then lowered or positioned on the intermediate plate (4), causing the points (5) of the protrusion (3a) to pass through the lining (13), to fix its position in the mould, with said points (5) being inserted into the holes (6) on the edge (4b) of the intermediate plate while the protrusion (3a) is inserted into the recess (4c) of the plate (4). After this operation, the upper part (3) of the intermediate plate (4) is raised or separated again.

[0069] The next step is to cast the second material (12), preferably polyurethane, as filler material for the midsole (10), inside the first body (11), through the opening (4a) of the intermediate plate (4). Once said polyurethane (12) has been cast, the upper part (3) of the mould is again lowered or positioned on the intermediate plate (4) and the polyurethane is allowed to expand and cure.

[0070] Once the polyurethane (12), or second material, has cured, the upper part (3) and the intermediate plate (4) of the mould (1) are raised and the footwear midsole (10) is removed, which has several surplus areas (10a) generated by the perimeter tab of the first body (11), to the excess lining (13) and sometimes to the excess of the second material (12). These surplus areas are removed by manual or refined die-cutting.

[0071] Said midsole will have a first body (11) of a first material, preferably a rubber material with cork, with a perimeter wall of said material, an intermediate layer of a second material (12), preferably polyurethane, arranged immediately on the perimeter wall of the first body (11) and a lining (13) of a third material, preferably leather or microfibre, overlaid on the second material (12).

[0072] The design of the intermediate layer of the second material (12) is defined by the configuration of the side wall of the opening (4a) of the intermediate plate (4). This side wall may be, for example, concave, convex, flat, among other options, and in addition, may incorporate embossing or bas-reliefs, which may have different designs, such as animals, trademarks, flowers, geometric patterns, etc. The height of this wall will provide the height to the intermediate layer (12) of the second material.

[0073] Additionally, the lower surface of the intermediate plate (4) is complementary to the upper surface of the lower part (2) as well as to the shape of the perimeter tab of the first body (11). Consequently, by alternating the shapes of said surfaces, the shape of said intermediate layer of the second material (12) is modified.

[0074] Preferably, all of the parts (2, 3 and 4) of the mould (1) are joined together by a joint (8) and, in addition, they are equipped with closure elements (9) to seal the mould (1) prior to casting between the lower part (2) and the intermediate plate (4) and subsequently during the expansion and curing of the second material (12) after lowering the upper part (3) of the mould.

[0075] FIG. 5 shows the midsole (10) obtained with the described mould (1), prior to the removal of the surplus areas (10a) from the midsole.

[0076] FIGS. 6 to 8 show an exemplary embodiment of the midsole (10) obtained in the described mould (1) and according to the method object of the invention, showing the configuration of the same comprising a lower base (11) made of a first material, preferably rubber with cork, an upper lining (13) made of a third material, preferably leather or microfibre, and an intermediate layer, or body, (12) made of a second material, preferably polyurethane,

[0077] FIG. 6 shows an midsole (10) in which the different layers that make up the midsole (10) are visible, showing how the intermediate layer (12) of the second material extends above the perimeter wall, or walls, of the first body (11), and eliminating the direct support of the sole of the foot on said walls. This figure shows a decorative example of the intermediate layer, decorative, and therefore optional, markings (14) in the intermediate area (12) of the front part of the midsole, corresponding to several vertical lines in bas-relief. These decorative vertical lines correspond to lines embossed in the side wall of the intermediate plate and that were marked on the intermediate layer (12) of the second material during the manufacture process. Likewise, it shows how the lower side of this intermediate layer (12) is a line that is continuous and laterally flat. As mentioned, depending on the configuration of the intermediate plate (4), mainly of its side wall, as well as its lower surface, one design or another can be generated on the intermediate layer (12) of the footwear midsole (10).

[0078] FIG. 7 shows a longitudinal cross-section of the aforementioned midsole (10) which also shows the different components of the midsole (10), specifically, the void or hollow of the first body (11) and its perimeter wall or walls, as well as the filling of the second material that determines the intermediate layer (12).

[0079] FIG. 8 shows a cross-section in which the perimeter wall or walls of the first body (11) are shown, on which the second material of the intermediate layer (12) is overlaid, preventing the user from noticing, when resting the sole of the foot on the footwear midsole (10), that these perimeter walls are made of a first material that is harder than the second material, and therefore improving user comfort.

[0080] FIG. 9 shows an example of a footwear that incorporates a midsole object of the invention, specifically a sandal. The sandal has been manufactured starting from a midsole with a lower body (11), an intermediate layer (12) and a lining (13) where the foot of the user rests. Starting from the midsole, a leather or upper part (16), made up of a strip designed to cover part of the instep of the user of the sandal, has been added to hold the foot to the midsole. Said leather (16) can be attached to the midsole by different means. In the case shown, the leather (16) is arranged between a sole (15) and the lower surface of the midsole, which are joined or bonded together preferably by means of an adhesive. The leather (16) can also be glued to the sides of the midsole.