EP2314178A1

EP2314178A1 - A midsole, particularly for shoes

Info

Publication number: EP2314178A1
Application number: EP10177507A
Authority: EP
Inventors: Armando Cietto
Original assignee: Ac Studio SNC Di Armando Cietto & C
Current assignee: SUGI INTERNATIONAL LIMITED
Priority date: 2009-10-22
Filing date: 2010-09-18
Publication date: 2011-04-27
Also published as: ITTV20090208A1

Abstract

The present application refers to a midsole, particularly for shoes comprising a lower surface (5a) which has an arc-like shape with the convexity directed toward the ground, and an upper surface on which there is, in the region between the tarsus and the metatarsus, a longitudinal seat for at least one elastically compressible insert which can be positioned detachably thereat.

Description

The present application relates to a midsole, particularly for shoes.
Nowadays, the prior patent W02006/010025 illustrating a midsole for Masai walking shoes is known which presents an essentially arc-like shape with the convexity directed toward the ground and, in the heel region, an insert made from a soft polyester sponge or a soft polyurethane sponge, the hardness of which is between 15 and 30.
The convex conformation of the midsole is indicated as the characteristic which may prevent malfunction of the skeletal-muscular system and maintain correct posture of the spinal column.
However such known solution presents several drawbacks: the insert being placed in the heel region and being made from soft material, it has been found that during the rolling motion and therefore during the phase in which the sole interacts with the ground while walking, a sensation of instability is generated for the user caused precisely by the softness of the insert, thereby causing potential aches in the cervical and lumbar regions as well as tension in the posterior muscles of the lower limbs.
Patent US2009/056165A1 is also known, illustrating an improvement on the previous solution wherein in the heel region there is a seat with elastically compressible elements; this solution too presents the same drawbacks as mentioned above.
Patent W02009/061103 is also known, illustrating an improvement on the previous solution wherein a front insert and a rear insert are present which can be positioned in seats adjoining a central protrusion projecting downwards; such solution also has drawbacks in that it is composed of multiple components which increase its structural complexity and thereby cost.
Furthermore, it cannot be modified according to the changing requirements of the single user, who may be subject to different pathologies.
Such solution requires, furthermore, many combinations of components, having different characteristics from each other depending on the relative and specific pathology of the user, thereby requiring the industrial manufacture of many types of shoes to satisfy the many requirements of the individual user; moreover such manufacture increases further given the fact that the same must be made in the various sizes.
The main object of the present invention is therefore to overcome the technical problems described, eliminating the drawbacks of the prior art mentioned and therefore devising a finding which makes it possible to produce a midsole, particularly for shoes, which is structurally simple and composed of a limited number of components, the same being adaptable in a rapid and simple manner to the specific requirements of the user so as to find ample application while industrially manufacturing a single product per size.
Within the sphere of the objective described above, another important object of the invention is to make a midsole which forces the user to adopt a constantly erect position and which, at the moment of walking, solicits the muscles all over the body so as not to burden solely the back muscles.
Another object of the invention is to make a midsole wherein during the rolling motion of the step, the foot, and in particular the metatarsus region, is not strained during such movement.
Another object of the invention is to permit activation of the small muscles responsible for stabilising the joints so that the skeletal muscular system imposes a postural adjustment by the user.
Another no lesser object is to obtain a device which has limited production costs and which can be made in the usual prior production plants.
The task and objects mentioned, as well as others which will appear more clearly below, are achieved by a midsole, particularly for shoes comprising a lower surface which has an arc-like shape with the convexity directed toward the ground, characterised in that it has an upper surface on which there is, in the region between the tarsus and metatarsus, a longitudinal seat for at least one elastically compressible insert which can be positioned detachably thereat.
Further characteristics and advantages of the invention will be clearly comprehensible from the detailed description of a specific, but not exclusive, embodiment, illustrated by way of a non-limiting example in the attached drawings, wherein:

fig. 1 shows, in an exploded view, the midsole which may be used with an insole and outsole;
fig.2 shows the midsole from above;
fig.3 shows the midsole from a lateral view;
fig.4 is a view taken according to the section plane IV-IV in figure 3;
fig.5 shows the various phases of the rolling motion of the step;
fig. 6 shows in a schematic lateral view, how the pressure in the point of the centre of gravity imposes a constantly erect posture which at the moment of oscillation solicits the muscular system of the entire body so as not to burden only the back muscles;
fig.7 and fig.8 respectively show a lateral and front view, a schematic view of the lower limbs of the pelvis.

In the embodiments which follow, single characteristics reported in relation to specific examples may, in actual fact, be interchangeable with other different characteristics existing in other embodiments.
Furthermore, it should be noted that anything which should prove already known during the patent application procedure is understood as not claimed and shall be the subject of a disclaimer from the claims.
With reference to the aforementioned figures, reference numeral (1) denotes a midsole, particularly for shoes, not shown, which may comprise a footbed advantageously divided into a pair of insoles (2a, 2b) advantageously of the ergonomic type and made in soft material to recreate the conditions of a pliant ground surface making walking more physiological, the same being placed to affect the regions (3) of the heel and the toe.
Such shoes also comprise a sole (5) which may be made from rubber or other plastic material.
The midsole (1) is made from plastic material and must enable a distribution of the load from the weight of the foot upon it, at least in the region (6) between the tarsus and metatarsus, corresponding approximately to that of the plantar arch; such midsole (1) may be made from a semi-rigid plastic material.
The midsole structure (1), and consequently the sole (5), if any, respectively have a lower surface (5a, 5b) of an arc-like shape with the convexity directed towards the ground.
Above the midsole (1), there is an upper surface (7) in the heel region (3) and toe region (4) of which the pair of insoles (2a, 2b) is associated and, in the region (6) between the tarsus and metatarsus there is at least one seat (8) which affects, in a longitudinal direction, part of the length of the midsole (1) approximately up to the heel region (3) and toe region (4).
Such seat (8) has longitudinal edges (8a, 8b) which advantageously follow the shape of the adjacent edge (9) of the midsole (1).
Advantageously, the seat (8) has transverse edges (10a, 10b) of different width, the width of the edge directed toward said toe region (4) being greater.
At said seat (8) at least one elastically compressible insert (11) can be positioned detachably.
The insert (11) is therefore located in a region (6) which corresponds to the region of the centre of gravity of the foot of the user.
The insert (11) is substantially shaped complementarily to the seat (8) which has, preferably, at the transverse edges (10a, 10b), temporary engagement means for complementarily shaped grip means present or associated with said at least one insert (11).
The temporary engagement means are composed of a pair of elastically deformable transverse tabs (13a, 13b), which retain the insert (11) in the seat (8) and which thereby snap-insert it into such seat (8).1
In the solution shown, the grip means are in fact constituted by the resting surface of the edges of the insert itself, other embodiments of such means also being possible, for example, grooves or projections interacting temporarily with said engagement means.
The temporary engagement means may, alternatively, be made or be present on the longitudinal edges (8a, 8b).
The insert is elastically compressible but at the same time rigid enough to create a centre of pressure towards the plantar arch, so as to determine a sensation of instability in the user as shown in figure 6, as if, for example, the user were standing with the arch of the foot, and therefore the centre of gravity of the foot, resting on a round sectioned rod acting as an element on which the foot pivots.
This way the body, and in particular the muscles of the trunk, are instinctively induced to move so as to constantly seek a point of balance of the body, thus determining the action of such muscles which are usually not used.
During the rolling motion of the step, illustrated in figure 5, a region (14) having constant dimensions is formed in which the surface (5a) or surface (5b) interact with the sole: in the intermediate condition, in which the region (14) is substantially at the region (6) between the tarsus and metatarsus, all the weight of the body pivots on the centre of gravity passing through said region (6) between the tarsus and metatarsus: the pressure of the weight of the body acting in the point of the centre of gravity imposes a constantly erect posture which at the moment of oscillation solicits the muscular system of the entire body so as not to burden only the back muscles.
During the rolling motion of the step the insert (11), being elastically compressible, absorbs the various pressures on the foot in the point of the centre of gravity and thereby prevents the region (6) between the tarsus and metatarsus from being strained by the movement.
The interchangeable nature of the insert (11) makes it possible to customise the midsole depending on the weight of the user.
In practice it has been observed that the invention accomplishes the aforementioned task and objects, a midsole having been created which is structurally simple in that it is composed of only two elements, the substitution of the insert according to the weight of the user making it possible to adapt the midsole quickly and easily to the specific requirements of the user so as to find a wide range of application while industrially producing a single product for each size and a multiplicity of inserts of varying rigidity or elasticity.
Furthermore, a midsole has been made which forces the user to adopt a constantly erect position and, when walking, solicits the musculature of the entire body so as not to burden exclusively the back muscles, and further during the rolling motion of step, the foot, and in particular the metatarsus region, is not strained by such movement.
Further, the midsole enables activation of the small muscles responsible for stabilising the joints so that the skeletal muscular system provides for a postural adjustment by the user, the invention having limited production, storage and transport costs.
Lastly, the insert is concealed inside the midsole so as not to alter the external aesthetic configuration.
Naturally, the materials used and the dimensions of the single components of the invention may be more pertinent, depending on the specific requirements.
The various means for performing specific different functions certainly need not coexist only in the embodiments shown but may be present in their own right in many other embodiments, even if not shown.
The characteristics indicated as advantageous, opportune or similar may even be absent or be replaced by other equivalent characteristics.

Claims

A midsole (1), particularly for shoes comprising a lower surface (5a) which has an arc-like shape with the convexity directed toward the ground,
characterized in that it has an upper surface (7) on which there is, in the region (6) between the tarsus and the metatarsus, a longitudinal seat (8) for at least one elastically compressible insert (11) which can be positioned detachably thereat.
The midsole according to Claim 1, characterized in that a pair of insoles (2a, 2b) made of soft material is associated on said upper surface (7) at the heel region (3) and at the toe region (4).
The midsole according to claims 1 and 2, characterized in that in said region (6) there is, at said upper surface (7), at least one seat (8) which affects in a longitudinal direction part of the length of said midsole (1) approximately up to said heel region (3) and toe region (4).
The midsole according to claims 1 and 3, characterized in that said seat (8) has longitudinal edges (8a, 8b) which follow the shape of the adjacent edge (9) of said midsole (1).
The midsole according to claims 1 and 4, characterized in that said seat (8) has transverse edges (10a, 10b) of different width, the width of the edge (10b) directed toward said toe region (4) being greater.
The midsole according to claims 1 and 5, characterized in that at least one elastically compressible insert (11) can be positioned detachably at said seat (8) and is located in a position that corresponds to the region of the center of gravity of the foot (12) of the user.
The midsole according to claims 1 and 6, characterized in that said insert (11) is shaped complementarily to said seat (8), which has, at said transverse edges (10a, 10b), temporary engagement means for complementarily shaped grip means which are associated with said at least one insert (11).
The midsole according to claims 1 and 7, characterized in that said temporary engagement means are constituted by a pair of elastically deformable transverse tabs (13a, 13b), which retain said insert (11) in said seat (8).
The midsole according to claims 1 and 8, characterized in that said grip means are constituted by the resting surface of the edges of said insert (11), said insert (11) being elastically compressible and at the same time rigid enough to create a center of pressure toward said plantar arch,
The midsole according to claims 1 and 9, characterized in that during the rolling motion of the step, a region (14) having substantially constant dimensions is formed, in the intermediate condition of said rolling motion in which said region (14) is substantially at said region (6) between the tarsus and the metatarsus, all the weight of the body being pivoted on said at least one insert (11) that is present in said region (6) between the tarsus and the metatarsus.