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(11) | EP 2 438 825 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Ventilating bottom and insole and related item of ventilated footwear |
| (57) A breathable, impermeable and elastically compliant composite insole (1) equips a
bottom (2) of an item of footwear (18) having a ventilated foot space (13) and whose
bottom (2) comprises an outsole (3) having holes (4) running through it for aerating
the foot space (13). The insole (1) has a multilayer structure comprising a first
layer (5) of microperforated, semirigid osmotic material, and a second layer (6) of
macroperforated, soft impermeable material which are made to adhere monolithically,
superposed over each other. The second layer (6) is larger in surface area than the
first layer (5) and forms, in combination with the latter, a continuous border (7)
which extends past the edge of the first layer (5) and which peripherally surrounds
the first layer (5) itself. A ventilating bottom (2) and an item of ventilated footwear
(18) form part of this invention.
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[0001] This invention addresses footwear manufacturing technology and, more specifically, relates to a bottom that integrates a ventilating insole and an item of ventilated footwear which in turn integrates the bottom and the insole.
[0002] In the manufacture of footwear, the use of footwear bottoms is known which are designed to allow aeration of the foot by forced ventilation of the foot space activated by the walking movements of the wearer.
[0003] As is known, the purpose of ventilation is to improve wearing comfort under conditions typically favourable to overheating and sweating of the foot. One prior art footwear bottom of this kind comprises an outsole having a plurality of through holes in it, made in a plantar zone of it. The inside surface of the outsole is equipped with an insole which is made of a microperforated material with osmotic properties and which faces the holes in the plantar zone, being interposed between the outsole and the foot space which accommodates the wearer's foot.
[0004] Thanks to the holes in the outsole and the microperforations in the structure of the material the insole is made of, the foot space is in communication with the outside of the footwear, allowing gases, and only gases, to flow from the inside to the outside of the footwear and vice versa, whilst liquids and solids are permanently prevented from passing through the footwear bottom. One disadvantage of this type of footwear is that the material the microperforated insole is made of is rigid, which does not provide comfortable support for the foot.
[0005] For this reason, in the case of winter footwear, it is common practice, in manufacturing the footwear, to place a soft liner under foot inside the foot space but physically separate from the breathable insole which, instead, by the very nature of the footwear design, is housed inside the footwear bottom underneath.
[0006] This solution cannot, however, be applied to summer shoes. In effect, in summer shoes, as is the case with certain Venetian style moccasin designs, for example, the volume of the foot space is quite limited in geometrical and dimensional terms.
[0007] As a result, a soft liner placed inside the foot space would further limit the latter's containment capacity. For this reason, all prior art summer shoes are, in practice, made without the soft liner, which obliges users to accept a rigid plantar support which is much less comfortable for walking.
[0008] The aim of this invention is to overcome the above mentioned disadvantages by providing a solution capable of conferring both breathability and soft support on any type of footwear, whether designed for summer or winter use.
[0009] According to the invention, this aim is achieved by a solution which essentially comprises a multilayer insole combining, in a single physical entity, properties of breathability and soft, compliant support; and which can be entirely incorporated as one into the bottom of the item of footwear without reducing the containment volume of the foot space and thus being applicable without distinction and without limitations of any kind to both winter and summer footwear.
[0010] The technical features of the invention, with reference to the above aims, are set out in one or more of the accompanying claims below and are more apparent, together with its advantages, from the detailed description which follows of a preferred non-limiting example embodiment of it, with reference to the accompanying drawings, in which:
- Figure 1 shows a footwear bottom according to the invention, as viewed from the tread side;
- Figure 2 shows the footwear bottom of Figure 1 as viewed from the foot space side and shown with some parts cut away in order to better illustrate others;
- Figure 3 is an assembly view of an insole according to the invention as viewed from the tread side;
- Figure 4 is an assembly view of the insole of Figure 3 as viewed from the foot space side;
- Figures 5 and 6 are cross sections of the insole, through a cutting plane labelled V-V in Figure 3 and through a plane labelled VI-VI in Figure 4, respectively;
- Figure 7 is a partial view of an item of footwear according to the invention, equipped with an outsole as shown in Figures 1 and 2 and with an insole as shown in Figures 3 to 6.
[0011] With reference to the accompanying drawings, the numeral 2 in Figures 1 and 2 denotes a footwear bottom comprising an outsole 3 provided with a tread face 11 having a zone with a multiplicity of through holes 4 and a groove 12 made on the inside surface of the bottom 2, located at the perforated zone of the tread face 11 and designed to accommodate a breathable, impermeable and elastically compliant composite insole 1.
[0012] The insole 1, illustrated in Figures 3 and 4, has an essentially multi-layer structure and comprises a first layer 5 microperforated, semirigid and made up of osmotic material, and a second layer 6 of macroperforated, soft impermeable material, the layers 5 and 6 being made to adhere monolithically, superposed over each other.
[0013] The expression "first semirigid layer 5" means that the layer 5 has elasticity modulus and thickness combined such that to guarantee structural support for the wearer while at the same time to allow predetermined compliance / deformability (in order to improve the comfort of the wearer of the item of footwear 18).
[0014] In other words, the first layer 5 serves a function of structural support but is not totally "rigid" (which would cause discomfort to the wearer) but is only partially rigid, having a certain amount of compliance which allows limited deformation. For this reason, the first layer 5 is defined as "semirigid".
[0015] Thus, the first semirigid layer 5 defines a structural support which allows a certain amount of compliance.
[0016] The expression "soft material", on the other hand, means that the material (which the second layer 6 is made of) is compliant / deformable to the touch (for example, in a preferred embodiment, the soft material consists of a foam).
[0017] The "soft material" the second layer 6 is made of is in direct contact with the sole of the footwear wearer's foot.
[0018] The "soft material", being compliant to the touch, adapts anatomically to the footwear wearer's foot and thus guarantees greater comfort for the wearer. More generally speaking, it should be noted that the elasticity modulus of the second layer 6 is lower than that of the first layer 5.
[0019] More specifically, the structure of the first layer 5 is microperforated throughout its mass and is permeable to gases and impermeable to liquids.
[0020] The second layer 6, which is made of impermeable polyurethane foam, has a multiplicity of macro holes 9 which are a few millimetres in diameter and which run through a central section of the second layer 6 surrounded by a continuous lip 16 of the soft material, without macro holes 9 running through its thickness.
[0021] As shown also in Figures 5 and 6, the second layer 6 has a surface area that is larger than the corresponding surface area of the first layer 5 and forms, in combination with the latter, a continuous border 7 which extends past the edge of the first layer 5 and which peripherally surrounds the whole of the first layer 5 itself.
[0022] Between the first layer 5 and the continuous border 7 of the second layer 6, extending past the edge of the first layer 5, there is formed a channel 8 which also runs right round the edge of the first layer 5.
[0023] The insole 1 is designed to be housed, through a monolithic impermeable joint, inside the groove 12 of the footwear bottom 2.
[0024] Said housing is obtained with the insole oriented in such a way that the first microperforated layer 5 faces towards the tread face 11 and the second macroperforated layer 6 accordingly faces in the opposite direction, that is to say, oriented towards the foot space 13 of the item of footwear (18) located above the bottom 2.
[0025] The joining means that embody this monolithic connection preferably include a layer 17 of adhesive material located between the continuous border 7 of the second layer 6 and, opposite it, a matching inside surface 12a of the tread face 11. Further, as may be seen in Figure 2 or, better still, in Figure 7, the connection means also include a continuous lip 16 formed on the inside of the tread face 11 and projecting from the tread face 11 towards the inside of the insole channel 8 which surrounds the first layer 5.
[0026] The lip 16 and the channel 8 together form a labyrinth seal which runs round the perforated zone of the tread face 11 of the bottom 2 and which increases the tightness of the seal, preventing liquids and dust on the ground surface from making their way round the insole 1 and reaching the wearer's foot inside the foot space 13.
[0027] In the context of footwear manufacturing technology, the solution described above offers numerous advantages, including the production-related one inherent in the fact that the manufacture of the insoles 1, of the footwear bottoms 2 and of the items of footwear the footwear bottoms 2 are applied to can be made modular and independent of each other.
[0028] Furthermore, the insole, since it is integrated in the structure of the footwear bottom, makes the latter applicable by the footwear manufacturer using a single manufacturing method for both ventilated and conventional footwear, without distinction. From this derives the possibility of simplifying and standardizing production processes, with obvious advantages in terms of economy of production.
[0029] At a strictly functional level, the integration of the insole 1 into the footwear bottom 2 and, as clearly shown in Figure 7, outside the foot space 13 - symbolically delimited by an upper 14 and by a slim liner 15 under foot - offers the advantage of giving any type of shoe or item of footwear 18 the comfort of ventilation and soft support simultaneously, irrespective of whether the footwear is designed for summer or winter use.
[0030] The method of manufacturing the footwear bottom can be summarized in the following basic steps which relate to preparing - for example by injection moulding - a semifinished body for a footwear bottom 2 having a tread face 11 with a plurality of holes 4 running through it;
preparing a breathable, impermeable and elastically compliant composite insole 1 by adhesion of a first microperforated layer 5 of semirigid, osmotic material, and a second macroperforated layer 6 of soft, impermeable material superposed over each other, the first and second layers 5, 6 being of shape and size such that, in combination with each other, they form on the second layer 6, a projecting border 7 surrounding the first layer 5; and connecting the composite insole 1 and the body of the footwear bottom 2 along the border 7.
[0031] The connection may be made by gluing or any of several equivalent means such as, for example, ultrasound sealing.
[0032] Regarding the connection, it should be noted that the lip 16 protruding from the inside surface 12a of the tread face 11 and projecting towards the front channel 8 of the insole 1 has - besides the purpose of providing a tight seal - the important purpose of centring the insole 1 on the body of the footwear bottom 2, this centring action making it possible to correctly guide the assembly between the insole 1 and the bottom 2 when these two parts are made at different times, at different places and by different operators.
1. A bottom for an item of footwear (18), comprising: an outsole (3) provided with a
tread face (11) having a zone with a multiplicity of through holes (4) and a groove
(12) made on the perforated zone of the tread face (11), the bottom being characterized in that it further comprises an insole (1) with a multilayer structure comprising a first
layer (5) of osmotic material, microperforated and semirigid, and a second layer (6)
of macroperforated, soft impermeable material superposed over each other and made
to adhere to each other, the second layer (6) being larger in surface area than the
first layer (5) and forming, in combination with the latter, a continuous border (7)
which extends past the edge of the first layer (5), peripherally surrounding the first
layer (5) itself, and which delimits with the latter an interposed channel (8) that
surrounds the first layer (5); the insole (1), with a composite structure, being housed
inside the groove (12) with the first, microperforated layer (5) facing towards the
tread face (11) and with the second, macroperforated layer (6) accordingly facing
towards the opposite direction.
2. The bottom according to claim 1, characterized in that it comprises connection means for obtaining a tight sealed monolithic joint between
the insole (1) and the bottom (2).
3. The bottom according to claim 2, characterized in that the connection means include a layer (17) of adhesive material located between the
continuous border (7) of the second layer (6) and, opposite it, a matching inside
surface (12a) of the tread face (11).
4. The bottom according to claim 2 or 3, characterized in that the connection means include a continuous lip (16) projecting from the tread face
(11) towards the inside of the insole (1) channel (8) which surrounds the first layer
(5), the lip (16) and the channel (8) forming, in combination with each other, a labyrinth
seal which runs round the perforated zone of the tread face (11) of the bottom (2).
5. The bottom according to any of the foregoing claims, characterized in that the structure of the first layer (5) is microperforated throughout its mass and is
permeable to gases and impermeable to liquids.
6. The bottom according to any of the foregoing claims, characterized in that the second layer (6) has a multiplicity of macro holes (9) running through it, which
are a few millimetres in diameter and which run through a section of the second layer
(6) surrounded by a continuous impermeable edge (10) of the soft material.
7. The bottom according to any of the foregoing claims, characterized in that the second layer (6) is made of polyurethane foam.
8. An item of footwear with ventilated foot space, characterized in that it comprises a bottom (2) according to any of the foregoing claims.
9. A method for manufacturing a bottom (2) of an item of footwear (18), which is breathable,
impermeable and provides soft foot support, characterized in that it comprises the steps of:
- preparing a semifinished body of a footwear (18) bottom (2) having a tread face (11) with a plurality of holes (4) running through it;
- preparing a breathable, impermeable and elastically compliant composite insole (1) by adhesion of a first semirigid microperforated layer (5) of osmotic material, and a second macroperforated layer (6) of soft impermeable material superposed over each other, the first and second layers (5, 6) being of shape and size such that, in combination with each other, they form on the second layer (6), a projecting border (7) surrounding the first layer (5) and delimiting with the first layer (5) a channel (8);
- and connecting, along the projecting border (7), the composite insole (1) to a groove (12) made in the body of footwear (18) bottom (2), with the first, microperforated layer (5) facing towards the tread face (11) and with the second, macroperforated layer (6) accordingly facing towards the opposite direction.
10. The method according to claim 9, characterized in that the step of connecting the insole (1) to the bottom (2) of the footwear (18) is accomplished
by gluing the border (7).
11. The method according to claim 10, characterized in that the step of connecting the insole (1) to the body of the bottom (2) is preceded by
a step of centring the insole (1) on the body of the footwear bottom (2) so as to
guide it by inserting into the front channel (8) of the insole (1) a protruding lip
(16) projecting from the opposite inside surface (12a) of the tread face (11) of the
footwear (18) bottom (2).