EP3169176A2

EP3169176A2 - Multi-purpose diabetic shoes with optimized construction

Info

Publication number: EP3169176A2
Application number: EP15749963.3A
Authority: EP
Inventors: Michal SPACEK
Original assignee: Shaper Solution SRO
Current assignee: Shaper Solution SRO
Priority date: 2014-07-17
Filing date: 2015-06-29
Publication date: 2017-05-24
Also published as: CZ2014503A3; WO2016008458A2; CZ305699B6

Description

MULTI-PURPOSE DIABETIC SHOES WITH OPTIMIZED CONSTRUCTION

Technology field

The innovation concerns multi-purpose diabetic shoes with optimized construction, suitable as a casual, formal and hiking footwear.

Present state of the art

The special footwear for diabetics is designed in a way that it is able to prevent further irreversible physiologiocal changes on the legs of diabetics. The main aim of this footwear is to protect the legs of diabetic from possible injury and further defect.

Regarding the correct physiological solution, the most important aspect of the design is the structure of its insole. There are many kinds of insertable or stretching insoles currently on the market, that are designated to provide the best possible comfort and fit for their user. At the same time, they should completely stop or mitigate inherited or gained foot deformations or walk faults. Vast number of these products is also adapted to massage the foot and to stimulate its nerve endings.

Insoles of shoes can be classified in two main groups differentiating in their construction. Firstly, there are insoles that contain a layer of suitable deformable material, such as cork, which temporarily or infinitely adapts to the shape of the foot of theis user. Among these soles belongs for example the solution according to the german patent file no. 3406504, where the insoles includes as well a layer consisitng of cork mash joint by soft glue, which adapts to the lower shape of user's foot during its wear. The same solution concerns for instance japanese patent filing no. 20012994008, where one of the layers of the insole consists of cork, which adapts to the lower shape of foot of its user after longer wear duration. These solutions have, though, significant disadvantages - if the user has, for example, incorrectly formed foot, the inner sole copies the wrong shape and instead of curing such fault, it actually keeps worsening the foot during long term use.

Second group of insoles are items, on whose upper side, which is in contact with the foot of the user, is modelled a relief, whose area more or less corresponds with the footprint of the foot. Among such solutions belongs for example solution described in japanese patent no. 7039402, where the area of the insole, which is in contact with the foot of the user, is formed by groups of protrusions and dimples. The disadvantage of such solution is, though, that it is formed on a unified shape of human foot and doesn't reflect the individual shape. This is especially exhibited in the differences of shape and the incline of toes, hence the foot adapts to the shape of the insole and not the other way round, as it should be.

However, when using either kind of the described insoles, the weight distribution of the body mass over the footprint between the toe joint, pinkie joint and heel bone isn't ideal and hence the longitudinal and cross arch of the foot is enlightened. That means that during every step, there are wrong pressures to the bloodstreams in the soft areas of the foot. Moreover, not all of the lower limb muscles are ideally loaded, so some muscles and sinews on foot are over-encumbered, while some are not in move at all. Using currently known inner soles then leads not only towards higher fatigue, but towards other physical, or even psychical issues, which worsen with higher age.

Eliminating these shortcomings are subject of solution in the Czech patent no. 298894, which describes the insole of footwear, whose upper surface is modelled into the face in the shape of the footprint of the human foot and whose lower face is in the shape of the lower part of human foot with flat toe part. Similiar in idea is as well solution of the Czech utility model no. 16872, where is in addition created dimple for the toe joint.

Other special kinds contain cushioning areas ultilizing gel filament - such as solution subjected to the Czech patent filing PV 2009-219, where at the upper face of structural bearing layer of a sewable insole is added sculpted component, which has got hollows in the areas of the highest pressure concentration, especially in the area under the toes, area between the metatarzal bones, area under the central and side part of the foot and in the area under the heel bone. According to the principle of negative-positive, into these hollows fit similiarly designed elevated components from the gel filament placed in the lower dampening layer of the insertable sole.

Improved solutions of the design of the insole often interfere with optimized construction of the whole shoe. Footwear specified in the european patent filing EP1997/006565, for instance, consists of a top and lower bearing part, which is joined to the mentioned vamp, and it includes outsole with intentionally integrated wedge heel. That is adapted for placement of internally sorted insole or auxiliary insole with supportive elements (based on a layer of granulated material, for example) at least under a part of this internally sorted insole. These supportive elements elastically deform under the user's weight, which in effect causes internally sorted insole to deform in such way, that it permanently takes the unique anatomic shape of the foot of the user of such shoe. Czech application of the invention PV 1991-3921 has a solution where the inside surface of the lower part of the footwear, which is in touch with the user's foot, is anatomically formed and it works as an elastic pad for the foot. Beneath this pad is placed at least one stiff layer, for example from wood or hard plastic. Sole is manufactured from elastic, however long-lasting material. The whole lower part of the shoe is, especially in the toe part and with a benefit as well in the heel part, turned upwards. The stiff layer is produced with a cut-out in the toe part or is elastic in the same part.

As was already stated, the next important requirement of the shoe is effective solution of the correct outlet of the vapour, which is created inside the shoe. For instance, in the USA patent no. 5044096 and European patent no. 0382904 is described outsole produced form plastic, that is devided into two layers, between whose is inserted breathable, but water-proof membrane (from Gore-Tex material, for example).

Patent filing USA 2002/157278 describes breathable footwear, that consits of breathable vamp and breathable insole joined togehter by quilted seam. Beneath the insole is joined breathable and waterproof membrane. Simple unit of elastomer outsole with passable holes is joined to the vamp/insole unit by glue or by direct injection.

Pending patent PCT 02/32246 describes footwear with an outsole, whose sole is perforated by a number of drains in the form of a valve so, that the vapour permeating down through the multi-layer outsole, which is sorted over them, has to be firstly directed to the narrow drains.

Footwear optimized with focus on user comfort, suitable for diabetics, especially as a work footwear designated into difficult enviroments, is subject of public Czech patent filing PV 2009-365. Vamp of the shoe is, in the instep area, where it transitions to the complete tongue (that's critical regarding bruises), equipped with cushioning. In the tip of the shoe, it is equipped by steel support and with plastic thermo-heel protector in the heel part. There is a lining held together by zig-zag grade seams with a tri-puncture, which is supported by glued technical tape and it's then joined to the sewable insole. To its cork shaping element is joined tread layer of the outsole out of elastomer mixture via intermediate layer of injected thermoplastic elastomer. The insole structure is composed not only out of mentioned sewable insole, but as well out of insertable insole. The sewable insole has got modelled component on the upper face of its structural bearing layer, which has got hollows in the areas of the highest pressure concentration, especially in the area under the toes, area between the metatarzal bones, area under the central and side part of the foot and in the area under the heel bone. According to the principle of negative-positive, into these hollows fit similiarly designed elevated components from the gel filament placed in the lower dampening layer of the insertable sole.

Above described footwear has an optimized construction suitable for diabetics, however, its construction was designed for work shoe, which is not suitable for other uses, such as casual, formal or hiking footwear.

Subject matter of the invention

Multi-purpose footwear for diabetics with optimized construction described in the invention does away with mentioned disadvantages, suitable as casual, formal or hiking footwear with outsole glued to the vamp of the shoe. The main idea of the invention lies in the novel production of the footwear fot diabetics, described by following traits:

• the derb vamp of the footwear has got lowered derb with the ability to compensate for minor foot deformations by special closing mechanism,

• stiffening vamp elements, especially heel protector and welt, are made of elastic thermoplastic materials with the shape memory,

• the inner equipment of the shoe consists of sewable insole with lower non-wowen fibrous layer and upper lightened layer with open pores and shape memory, complimented by insertable insole consisting of lower layer, which has heightened formed gel components on its lower side in the areas of the highest foot stress, especially in the area under the fingers, under the metatarzal bones, area under the middle and rear side parts and under the heel bone,

• the heightened components with gel filament can be embedded by pressure in the upper lightened layer of the sewable insole with shape memory,

• the insertable insole also includes middle layer based on the dampening foam with shape memory and upper textile layer,

• the glued outsole part contains midsole based on lightened polyurethane and on-step contact layer based on compact thermolastic polyurethane

To its benefit, the sewable insole has got upper lightened layer based on polyurethane foam with open pores and shape memory joined to the upper surface of the non-wowen fibrous layer. The hightened gel components can be embedded by pressure in this lightened layer of the insertable insole, are manufactured from compact polyurethane with the ability of compensation for the reduction of the tissue on the foot, and thus reduce the risk of skin creaks and creation of ulcers. The insertable insole contains . lower and middle layer based on the dampening materials with open pores, while in order of better air circulation, these layers are spot-joined around the foot.

With benefit, the lower layer of the insertable insole is made of permanently elastic polymer material, especially from polyurethane with open pores, without permanent deformation resulting from the ballast of the human body.

With benefit, the middle layer of the insertable insole is manufactured from shape polymer foam, especially based on polyurethane with open pores with the ability of adapting to the original shape of the foot of the user, including possible deformations or even smaller amputations.

With benefit, the midsole of the outsole part can be manufactured from lightened polymer material, especially polyurethane, that can dampen the hits during walk. As well with benefit, in order to improve stability during walking, the contact layer of the outsole overlaps the vamp by 3 mm to 4 mm and it's made of polymer material, especially of compact polyurethane and it's furnished with finely cut tread with anti-skid attributes.

Overview of Figures in the drawings

For a better understanding of the invention, please see attached blueprints, where: Fig. 1 - is the composition and execution of single components of the footwear for diabetics according to the invention,

Fig. 2 - shows the outer appearance of the footwear regarding the invention - in the male version

Fig. 3 - shows the outer appereance of the footwear regarding the invetnion - in a female version

Example of application of the invention

Multi-purpose footwear for diabetics with optimizd construction in the production sample (see fig. 1) is, due to its derb vamp 1 with lowered derb and closing mechanism able to compenate for possible minor foot deformations. The stiffening vamp elements, especially heel enforcement and welt, are manufactured from elastic thermoplastic materials with shape memory. The vamp has got different appearance in male footwear (see fig. 2) and female footwear (see fig. 3). The inner equipment of the shoe (see fig. 1) consists of sewable insole 2 with lower non-wowen fibrous layer 2T and upper lightened layer 22 with open pores and shape memory, complimented by insertable insole 3 consisting of lower layer ϋ which has heightened formed gel components 3Λ (note: in fig. 1 is the lower layer 3J picturd in the view from below) on its lower side in the areas of the highest foot stress, especially in the area under the fingers, under the metatarzal bones, area under the middle and rear side parts and under the heel bone. These heightened components with gel filaments 3_^4 can be embedded by stress in the upper lightened layer 2_2 of the sewable insole 2 with shape memory. The insertable insole 3 includes middle layer 3_^2 based on the dampening foam with shape memory and upper textile layer 33. Glued outsole part 4 includes midsole 4 based on the lightened polyurethane and on-step contact layer 4_^2 based on compact thermoplastic polyurethane.

The sewable insole 2 has got upper lightened layer 2_^2 based on polyurethane foam with open pores and shape memory placed on the upper surface of the lower non-wowen fibrous layer 2J,. In mentioned lightened layer 22 are hightened gel filled components 3.4. which can be embedded by pressure in the insertable insole 3. These components are manufactured from compact polyurethane with the ability to compensate for reduction of tissue on foot and can lower the risk of skin creaks and ulcer creation.

The insertable insole 3 includes lower layer 3_J_. and middle layer 32 based on dampening materials with open pores, whereas these layers 3_^1, 3_^2 are spot-joined in order to provide air circulation around the foot. The lower layer _A of the inserbatle insole 3 is made of permanently elastic polymer material, especially from polyurethane with open pores without permanent deformation resulting from ballast. The middle layer 32 of the insertable insole is made of shape polymer foam, especially based on polyurethane with open pores with ability to adapt to the original shape of user's foot, including possible deformations or even minor amputations.

The midsole 4J_ in the outsole part 4 is manufactured from lightened polymer material, especially form polyurethane with the abiity to dampen hits during walking. The contact layer 4_^2 in the outsole part 4 overlaps the vamp by 3 mm to 4 mm. It is produced from polymer material, especially from compact polyurethane and it's provided with finely cut tread with anti-skid attributes.

Claims

P A T E N T C L A I M S

1. Multi-purpose diabetic shoes with optimized construction suitable as a casual, formal, or hiking footwear with outsole part glued to the vamp, is significant because its derb vamp (1) with lowered derb and closing mechanism able to compensate for possible minor foot deformations. The stiffening vamp elements, especially heel enforcement and welt, are manufactured from elastic thermoplastic materials with shape memory. The inner equipment of the shoe consists of sewable insole (2) with lower non-wowen fibrous layer (2.1) and upper lightened layer (2.2) with open pores and shape memory, complimented by insertable insole (3) consisting of lower layer (3.1), which has heightened formed gel components (3.4) on its lower side in the areas of the highest foot stress, especially in the area under the fingers, under the metatarzal bones, area under the middle and rear side parts and under the heel bone. These heightened components with gel filaments (3.4) can be embedded by stress in the upper lightened layer (2.2) of the sewable insole (2) with shape memory, then middle layer (3.2) based on the dampening foam with shape memory and upper textile layer (3.3) while the glued outsole part (4) includes midsole (4.1) based on the lightened polyurethane and contact layer (4.2) based on compact thermoplastic polyurethane.

2. Muti-purpose diabetic shoes according to the claim no. 1 claim, is significant, because the sewable insole (2) has got - on the upper surface of the lower non-wowen fibrous layer (2.1) -joined upper lightened layer (2.2) based on the polyurethane foam with open pores with shape memory, while in this lightened layer (2.2) are hightened gel components (3.4), that can be embedded in the insertable insole (3), which are produced of compact polyurethane with the ability to compensate for reduction of tissue on foot and lower the risk of skin creaks and ulcer creation.

3. Multi-purpose diabetic shoes according to the claim no. 1, is significant, because the insertable insole (3) contains lower layer (3.1) and middle layer (3.2) based on dampening material with open pores, while these layers (3.1, 3.2) are spot-joined in order to improve air circulation around the foot.

4. Multi-purpose diabetic shoes according to the claim no. 1, is significant, because the lower layer (3.1) of the insertable insole (3) is made of permanently elastic polymer material, especially from polyurethane with open pores, without permanent deformation due to ballast.

5. Multi-purpose diabetic shoes according to the claim no. 1, is significant, because the middle layer (3.2) of the insertable insole (3) is made of polymer shape foam especially based on polyurethane with open pores and with the ability to adapt to original shape of user's foot, including possible deformations or even minor amputations.

6. Multi-purpose diabetic shoes according to the claim no. 1, is significant, because the midsole (4.1) of the outsole part (4) is made of lightened polymer material, especially polyurethane with the ability to dampen hits during walking.

7. Multi-purpose diabetic shoes according to the claim no. 1, is significant, because the contact layer (4.2) of the outsole part (4) overlaps the vamp by 3 mm to 4 mm in order to imropve stability during walking.

8. Multi-purpose diabetic shoes according to the claim no. 1, is significant, because the contact layer (4.2) of the outsole part (4) is made of polymer material, especially compact polyurethane and it^'s provided by finely cut tread with anti-skid attributes.