EP1586247A2

EP1586247A2 - Footwear provided of an interchangeable sole

Info

Publication number: EP1586247A2
Application number: EP05102844A
Authority: EP
Inventors: Luciano Salotto; Lucio Vaccari
Original assignee: FRA-SER SpA
Current assignee: FRA-SER SpA
Priority date: 2004-04-15
Filing date: 2005-04-11
Publication date: 2005-10-19
Also published as: ITVR20040058A1; EP1586247A3

Abstract

Footwear provided with means that give the sole interchangeable features, consisting of uppers with a lower surface or insole (14) and a sole (10), the lower insole of the uppers and the upper surface of the sole (10) opposite to the walking surface being fitted with means designed to allow mutual interchangeable coupling.

Said means consist of a series of pins and/or capsules (12) positioned on the upper surface of the sole (10) designed to be inserted in respective cavities (13) in the surface of the insole (14).

Description

TECHNICAL FIELD

This invention concerns footwear equipped with means that provide the sole with interchangeable features.
More specifically, this invention refers to footwear provided with means that make it possible to temporarily combine different soles with different uppers, being compatible with each other.
This footwear consists of uppers with the lower surface having elements for coupling and fixing to the upper surface of the sole opposite to the walking surface.
This invention can be applied in the footwear production sector and in particular in the production sector of special footwear which can be used simultaneously for different purposes, that is to say having multi-purpose features.

BACKGROUND ART

It is known that in the footwear sector many different construction processes are employed in order to make the machining phases more practical or to make the use of the footwear by the user more comfortable or practical or even more original.
Among the requirements to which those working in the sector pay particular attention is the need to make the footwear as versatile as possible for different environmental conditions or for the different times the footwear is used or even according to fashion tastes.
One could, for example, envisage the possibility and the need to use the same footwear during relaxation and leisure time and also in places where more formal attire is necessary.
More simply and more in general, the need may occur whereby the user wishes to have different types of sole according to the different uses without having to change footwear every time.
According to other aspects it may be necessary to produce footwear with soles provided with interchangeable features, so as to make them easy to replace, for example when worn out, replacement being carried out directly by the user.
Some solutions for interchangeable soles are currently foreseen in the footwear sector, allowing the soles to be replaced.
Interchangeable soles are, for example, known whereby the sole is equipped with snap-fit elements that engage with a corresponding profile in the lower part of the uppers.
Such traditional systems for joining the uppers and the sole normally foresee means which ensure the coupling and blocking of the elements.
In some cases, Velcro is used, with the gripping surfaces applied on the lower surface of the uppers and the upper surface of the sole opposite to the walking surface.
In other cases, snap-fit elements have also been used that can be fixed with screw-type means which pass through the surfaces longitudinally or in other more appropriate directions so as to hold them together.
Each of these solutions has obviously presented various problems of a practical nature, and from an esthetic point of view they do not present "acceptable" characteristics for the users. In the majority of cases, therefore, these solutions have not encountered the necessary customer satisfaction to justify large-scale marketing.

DESCRIPTION OF THE INVENTION

This invention proposes to provide footwear with an interchangeable sole, the means permitting the interchangeable feature being constructed in such a way as to eliminate or reduce the problems indicated above.
The invention also proposes to provide footwear with interchangeable soles that can be easily constructed so as to be economically advantageous.
This is achieved by means of interchangeable footwear whose features are described in the main claim.
The dependent claims of the footwear with interchangeable soles according to the invention describe advantageous embodiments.
The main advantages of this solution , in addition to those ensuing from the construction simplicity rather than the traditional complexity of the known coupling means, concern above all the security of the coupling between the contact surfaces of the upper and the removable sole.
In addition, the quality of the footwear is higher and the esthetic result is evident, since it can also become a considerable attraction in the colourful and multifaceted world of fashion.
The solution in question also offers the not-indifferent advantage of allowing the sole, being interchangeable, to be replaced directly by the user, for example when it is worn out or also for different environmental situations, without having to totally replace the footwear and without requiring the assistance of technicians or repairers working in this sector.
The footwear according to the invention therefore consists of uppers, the lower part of which presents layers of different material alternated with foils and other materials that alternate to allow the use of pins designed to be accommodated in respective cavities in the uppers and/or the sole.
According to a preferred embodiment of the invention, pins are used in the upper part of the sole, i.e. the surface opposite to the walking surface, which are accommodated in the respective housings in the lower surface of the sole.
These pins protrude from surfaces which can have a cellular structure containing a special fluid designed to form a coupling that creates pressure, giving the coupling the necessary stability.
The pins consist of capsules made from elastic material and which, being positioned along a fluid line, can be subjected to an increase in pressure so that they are conveniently dilated inside the housing in the opposite part of the coupling.
According to advantageous embodiments of the invention, the upper surface of the sole consists of a layer of moulded plastic film presenting truncated cone shaped protrusions, arranged with their axis perpendicular to the plane of the sole's upper surface.
The lower surface of the plastic film presents a series of incisions which connect all the protrusions.
By polymerising this film with the body of the sole, we obtain microtubes which connect the truncated cone shaped cavities forming the protrusions. Both the microtubes and the cavities must be filled with an incompressible fluid.
Corresponding with each protrusion in the sole is a cylindrical hole in the uppers, with a diameter greater than the diameter of the relative protrusion.
To insert the protrusion in the hole, it is sufficient to join the sole to the uppers by means of a two-pin system that makes alignment easy and, once the insertion has been carried out, by turning a screw in the heel which pushes a piston, the fluid is pressurised causing the protrusions to dilate and expand until they occupy the entire space in the hole. The coupling is thus transformed from a free coupling to a forced coupling, constraining the sole and uppers together until the screw is turned anticlockwise to reduce the pressure, restoring the free coupling condition and allowing the sole to be detached from the uppers.
In addition to the cylinder designed to generate pressure, an expansion chamber is also necessary to allow the fluid to limit the overpressure caused by normal walking.
As an alternative to the microtubes, a thin layer of porous material can be used between the impermeable layer of the protrusions and an impermeable layer designed to contain the fluid.
Other coupling possibilities are also foreseen and will be described and illustrates in the following description of the possible embodiments.

DESCRIPTION OF THE DRAWINGS

Other features and advantages of the invention will become evident on reading the description given below as a non-binding example, with the help of the drawings shown in the accompanying figures, in which:

figure 1 represents a schematic cross-section view of the hydraulic system for coupling the sole with the uppers through the use of microtubes, with the two parts still separate;
figure 2 shows a cross-section view of the sole coupled with the uppers, with one of the blocking pins in the expanded condition;
figure 3 represents a schematic view of a fluid compression element in the hydraulic system;
fig. 4 shows a view of the expansion chamber inserted in the fluid circuit, designed to compensate for any excessive compression;
figure 5 is the schematic view of a sole coupled with the uppers by means of a vacuum type system;
figure 6 is an alternative to figure 7 without the foil if the material, the deformation of which can be noted, is sufficiently rigid, and is the schematic view of a sole coupled with the uppers in the vacuum solution, in a stage prior to blocking;
figure 7 is a schematic view of the coupling system with the parts blocked;
figure 8 shows a blocking pin in a stage prior to insertion in the respective housing where it is held in place by heat-dilation type means;
figure 9 is a view of the pin and the heat-dilation coupling system in the insertion and blocking stage;
figure 9a is a schematic view of the bimetallic foil type blocking pin;
figure 10 is a schematic view of the pin which is inserted in the uppers by means of an EAP type fibre coupling system;
figures 11 to 13 represent schematic views of the pin and the respective blocking system in conditions prior to and following insertion and blocking;
figures 14, 15 and 16 represent schematic views of the blocking system using pressurised microtubes;
figure 17 shows a schematic view of a construction detail of the solution using piezoelectric crystal and EAP fibres.

DESCRIPTION OF ONE EMBODIMENT OF THE INVENTION

The footwear provided with an interchangeable sole according to the invention foresees the preparation of a sole whose upper surface, that is the one opposite to the walking surface, is fitted with protruding/withdrawing means designed to couple with respective protruding/withdrawing means in the lower surface of the uppers.
According to the solution shown in figure 1, the sole 10 comprises an upper surface 11 equipped with a plurality of pins 12 designed to be inserted and blocked in housings 13 present in the lower surface of the uppers 14.
In this case, a grommet 15 is present at the mouth of each housing 13.
More specifically, the upper surface of the sole 10 consists of a layer of moulded plastic film 11, with hollow truncated cone shaped pins or capsules 12 made from elastic material and arranged with their axis perpendicular to the plane of the upper surface of the sole 10.
By means of a series of incisions, channelling 16 is cut in the lower surface of the plastic film 11, connecting all the capsules to each other.
By polymerising the film with the body of the sole, groups of microtubes are formed connecting all the truncated cone cavities 12' which form the capsules 12.
Both the microtubes and the cavities are filled with an incompressible fluid.
Corresponding with each capsule protruding from the sole, the uppers present cylindrical holes 13, the diameter of which is greater than the relative capsule.
To insert the capsule in the hole it is sufficient to couple the sole with the uppers by means of special pins, not shown in the drawings, which make alignment easy. A screw 17 (figures 3 and 4) inserted in the heel is then turned to press a piston 18, thus increasing the pressure of the fluid and dilating the capsules which expand until they fill the entire space between the capsule and the hole.
This transforms the free coupling into a forced coupling, constraining the sole 10 and the uppers 14 until, by turning the screw 17 in an anticlockwise direction, the pressure is reduced and a free coupling condition is restored, allowing the sole to be detached from the uppers. In addition to the piston 18, designed to generate pressure, an expansion chamber 19 (figure 4) is foreseen, fitted for example close to the piston, allowing the fluid to limit the overpressure caused by normal walking.
According to one embodiment of the invention, the microtubes can be replaced by a thin layer of porous material between the impermeable layer of the capsules and an impermeable layer designed to contain the fluid.
Figures 5 to 7 show a type of coupling between the sole 10 and the uppers 14 which uses a vacuum type system.
In this case, a porous layer 20 is inserted in the central part between the sole 10 and the uppers 14 to separate them.
Also between the uppers and the sole, but along the edges where they come into contact with each other, a thin steel foil is inserted and is integral with the uppers 14.
After placing the sole in contact with the uppers, vacuum is created through the suction duct 22 generating forces that tend to crush the uppers against the sole.
This effect is particularly marked on the thin steel foil 21, which will rest against the sole only along the edges.
Various solutions based on the same principle are possible.
Figures 8 and 9 show a solution in which the capsule pins are made from a rigid material and are inserted in respective housings which dilate with heat.
In this case the upper part of the sole 10 is integrated with a small surface 23 that forms the finish of the sole.
The lower side of this surface 23 consists of a layer of resistant material 24 which can be connected to sources of electrical energy and in which small aluminium tubes 25 are set with their axis perpendicular to the plane of the upper side of the sole.
In correspondence with each tube 25 are cylinders 26 made from material not subject to dilation, such as "invar", "superinvar" or plastic material, and integral with the uppers. The diameter of the cylinders is slightly larger than the diameter of the hole in the corresponding aluminium tube 25 at room temperature.
The cylinder 26 cannot be inserted in the cavity of the tube 25 at room temperature.
To carry out the insertion it is necessary to connect two wires present in the finish of the uppers to an external source of electromagnetic power in order to heat the layer of resistant material to 80 degrees or more.
In this condition, the tubes 25 dilate, in particular the inner cavity dilates, allowing insertion of the cylinders 26 into the respective tubes 25.
This permits the coupling of the sole 10 with the uppers 14, that is to say the tubes 25 with the cylinders 26.
In this case too, alignment is made easier thanks to a two-pin system, not shown in the drawings.
Once insertion has been completed, the current is detached from the resistant material 24, and as the temperature decreases the free coupling is transformed into a forced coupling.
When the wires present in the footwear are connected to a power source and the tubes 25 are heated to an appropriate temperature, the conditions of free coupling are restored, allowing the sole 10 and the uppers 14 can be separated.
This solution can make use of known resistant material and relative electronic circuits, with dimensions that can also be extremely limited and miniaturised.
In actual fact, instead of metal the tubes 25 can be made from special plastic materials such as "Hard polyurethane", which has a higher dilation coefficient than metals.
The thickness of the layer of resistant materials 24 and of the tubes 25 can be several tenths of a millimetre.
A variation of this solution, as shown in figure 9a, foresees replacing the whole tubes present in the previous solution with split tubes according to a cylinder generator or a helix, made from bimetallic material.
The feature of these split tubes, the inner part A being made from aluminium while the outer part I is made from invar, is that the variation in temperature leads to a more evident variation in the inner diameter of the tube, thus allowing a secure coupling even in the presence of a minor variation in temperature.
Figures 10 to 13 show a solution in which the pins of the sole are held in the respective housings in the uppers by means of extendable fibres 27.
In this case, the pin 28 which protrudes from the surface of the sole is made from rigid material and presents a circular groove 29 which accommodates the extendable fibre 27.
This extendable and retractable fibre consists of small inserts made from special material, such as piezoelectric crystal or EAP fibres or the like, which are inserted in a respective housing in the surface of the uppers 14 close to a respective hole 30, so as to retract from the hole when stimulated.
The inserts 27 are arranged longitudinally with respect to the surface of the uppers, thus being parallel to it.
These inserts are made from special rigid fibres of an appropriate length, for example around 20 mm, which shorten by a few tenths in the presence of electrostatic voltage.
Using appropriately shaped pins 28 achieves the objective of quickly constraining and releasing the sole 10 to and from the uppers 14.
Miniscule voltage generators are used to generate the charge needed to retract the fibre 27 from the hole 30 so that the respective pin can be extracted.
In all the cases indicated above, the pins protruding from the soles can also be positioned in the uppers, and the pins and respective holes can be positioned indifferently on the soles or the uppers.
Figure 17 shows the detail of this blocking system, whereby the EAP is fitted and blocked between two layers. According to the voltage applied by the conductor C, the end of the fibre F either remains flush with the wall of the cylindrical housing or penetrates the hole and blocks the pin.
According to other advantageous solutions of the invention, means can be foreseen that check the correct insertion of the pins in the respective holes.
These means, positioned in the lower part of the housing, can consist of electrical contacts connected to a network of conductors arranged in a matrix, which make it possible, using common external electronics, to check that each pin is correctly inserted in the corresponding housing.
This solution, to be considered as an optional, can be applied in all cases except for the vacuum solution, but is particularly economical when the pins are made from metal.
The check is carried out in a similar way to that used to manage keyboards, that is to say on a withheld basis, indicating the disconnections.
Briefly, line and column cross-connection systems are used, and when for example the first column is enabled and the lines have been read, the second column is enabled and the lines are read and so on, until all the columns have been completed.
For each type of footwear, mapping must be prepared and compared with the results.
The invention is described above with reference to a preferred embodiment. It is nevertheless clear that the invention is susceptible to numerous variations that are within its scope, in the framework of technical equivalents.

Claims

Footwear provided with means that give the sole interchangeable features, said footwear consisting of uppers with a lower surface or insole (14) and a sole (10), the lower insole of the uppers and the upper surface of the sole (10) opposite to the walking surface being fitted with means designed to allow mutual interchangeable coupling, characterised in that said means consist of a series of pins and/or capsules (12) positioned on the upper surface of the sole (10) designed to be inserted in respective cavities (13) in the surface of the insole (14).
Footwear provided with means that give the sole interchangeable features, characterised in that said pins (12) and respective cavities (13) are positioned indifferently in the insole (14) of the uppers or in the sole (10).
Footwear provided with means that give the sole interchangeable features according to either of the foregoing claims, characterised in that the upper surface of the sole (10) consists of a layer of moulded plastic film (11), in which hollow truncated cone shaped pins or capsules (12) are present, made from elastic material and arranged with their axis perpendicular to the plane of the upper surface of the sole (10).
Footwear provided with means that give the sole interchangeable features according to any of the foregoing claims, characterised in that the lower surface of said plastic film (11) presents channelling (16) consisting of a series of incisions or microtubes which connect all the capsules (12) to each other.
Footwear provided with means that give the sole interchangeable features according to any of the foregoing claims, characterised in that said microtubes (16) and the cavities of the capsules (12) are filled with an incompressible fluid.
Footwear provided with means that give the sole interchangeable features according to any of the foregoing claims, characterised in that instead of the microtubes (16) a thin layer of porous material is positioned between the impermeable layer of the capsules and an impermeable layer designed to contain the fluid.
Footwear provided with means that give the sole interchangeable features according to any of the foregoing claims, characterised in that said pins or capsules are made from rigid material and are inserted in respective heat-dilated housings.
Footwear provided with means that give the sole interchangeable features according to any of the foregoing claims, characterised in that the dilation of said housings is achieved by means of an external source of electromagnetic power which heats the layer of resistant material to 80 degrees or more.
Footwear provided with means that give the sole interchangeable features according to any of the foregoing claims, characterised in that according to a variation, instead of the whole tubes present in the previous solution, split tubes according to a cylinder generator or a helix, made from bimetallic foil, are used.
Footwear provided with means that give the sole interchangeable features according to any of the foregoing claims, characterised in that the sole pins are held in place in the respective housings in the uppers by means of extendable or retractable fibres (27).
Footwear provided with means that give the sole interchangeable features according to any of the foregoing claims, characterised in that said extendable fibres (27) are enabled by an electrical current and miniscule voltage generators, producing a charge allowing the pins to be extracted from the holes, are used to stimulate the fibre (27) so that it withdraws from the hole (30) thus freeing the space for extraction of the respective pin.