Patent Application
20180168277
The invention relates to a shoe, in particular a sports shoe, comprising a sole and a shoe upper, wherein the shoe upper has a first material section which at least partially extends around the foot of the wearer of the shoe. Furthermore, the invention relates to a method for tying such a shoe.
Shoes according to the generic kind are well known in the state of the art. The shoe upper is connected with the shoe sole and is tied at the foot of the wearer after putting on the shoe. Typically, therefore laces are used which pull two tensioning sections of the shoe upper which are arranged adjacent to another.
Other solutions use a rotary fastener for tying the shoe at the foot of the wearer.
However it can always be said in general that a respective tying step by pulling of a lace or of a tensioning wire must take place to fix the shoe at the foot of the wearer sufficiently.
It is the object of the invention to further develop a generic shoe and to propose a corresponding method for tying of the shoe by which it becomes possible to allow the tying of the shoe at the foot of the wearer in a more comfortable manner. Thereby it should be possible to do preferably without the use of laces or tensioning wires totally.
The solution of the object by the invention is characterized in that a second material section is arranged on the outside of the first material section which second material section at least partially covers the first material section, wherein the second material section consists of a plastic material having a shape memory effect (memory effect).
The second material section is thereby preferably applied onto the first material section as a laminar coating.
The second material section is preferably designed in such a manner that it exerts a first tensioning force (which force can if applicable be also (almost) zero) onto the first material section at a first, low temperature which presses the first material section against the foot of the wearer of the shoe and that it exerts a second tensioning force onto the first material section at a second, high temperature which second tensioning force is higher than the first tensioning force, preferably at least 20% higher than the first tensioning force. The material of the second material section is thereby preferably designed in such a manner that the first temperature is lower than 25° C. and the second temperature is higher than 35° C., preferably higher than 40° C.
The material of the second material section consists preferably of thermoplastic polyurethane (TPU) or comprises this material. The thermoplastic polyurethane comprises preferably hard segments and soft segments which form a block copolymer. The hard segments consist preferably of polyurethane groups. The soft segments consist preferably of long-chained polyester regions.
The material of the second material section is specifically preferred designed as net or lattice which rests on the first material section, wherein the net or the lattice comprises preferably a plurality of apertures.
A specifically preferred embodiment of the invention provides that the material of the second material section is electrically conductive. In this case it can namely furthermore be provided that the electrically conductive material of the second material section is in connection with a battery by which the electrically conductive material can be charged or flowed through with electrical energy and current respectively via a switch element. By doing so a heating of the second material section results.
The battery is thereby preferably rechargeable. The recharging process can thereby take place by induction for which purpose the shoe is placed on a respective loading station.
The proposed method of tying of a shoe comprises according to the invention the steps:
The heating up of the second material section takes place thereby preferably by using electrically conductive material for the second material section which is charged with current. Especially the heating up of the second material section can take place by actuating a switch element which induces current from a battery into the material of the second material section.
For rising the wearing comfort it can be provided that the shoe upper comprises a sock-like insert (like a kind of inner shoe); this insert can be arranged in the inner of the first material section. In the inner of the sock-like section an inner sole can be arranged in turn.
The second material section which is preferably designed net-like which functions as tensioning element can comprise a circumferential reinforcement edge in the region of the entry of the foot; this can be formed by a flat plastic band. Thereby, the net-like structure can extend down till the sole region; it can also extend completely around the bottom side of the shoe.
Thus, the invention is basing on the idea that the tying of the shoe takes place by using specifically the properties of a plastic material with shape memory. By a selective heating up the said material after putting on the shoe the second material section contracts slightly and exerts thereby the desired tensioning force onto the first material section of the shoe upper.
The following should be mentioned in connection with the second material section made of plastic with shape memory according to the invention: Such a material is available at the marked (trademark: Desmopan®, especially Desmopan DP 2795A SMP). This is a thermoplastic block copolymer which properties can be selectively influenced. The linear polymer molecules of the material consist of a combination of flexible elastic segments with low glass transition temperature and stiff crystalline segments with high melting point. By the selective variation of those hard and soft phases the properties of the material can be influenced.
The material is thermoplastic polyurethane (TPU) and has shape memory properties. The second material section which consists of this plastic material can be brought temporary into another shape and can be also fixed in the same. Thus, if only the soft segments are molten it is possible to force the part into a temporary shape and to cross-link physically the same by crystallisation of the soft segments and to stabilize the same by doing so. If the material is heated up above a predetermined temperature (so-called switching temperature) it “memorizes” its original shape and takes up the same again. This effect is used presently for tying the shoe. By a respective choice of the material components the switching temperature can be predetermined at about 40° C.
The shape memory effect is basing on the fact that the hard segments of the TPU form the phase with the highest transition temperature. This temperature is exceeded when the material is injection moulded to give it the permanent shape. The soft segments of the TPU which consists of long-chained polyester regions form a further phase with a significant lower transition temperature. When the switching temperature is reached only the soft segments melt so that the part can be brought into a temporary shape. During the cooling the soft segments link physically by crystallisation and the part remains this shape. Then, a later melting of the soft segment crystallites triggers the shape memory effect.
Beneficially by the realization of the second material section and using the mentioned plastic material it is reached that after execution of the tying process the shoe rests optimal against the foot of the wearer and a very equal pressure distribution onto the foot of the wearer is obtained.
In the drawing an embodiment of the invention is shown.
In the FIGURE an embodiment of the shoe according to the invention can be seen. The shoe 1 has a sole 2 and a shoe upper 3 which is connected with the sole 2. The shoe upper 3 has as a base layer a first material section 4; this material section is designed continuous and laminar and surrounds the foot of the wearer (not depicted). On the first material section 4 a second material section 5 is arranged; presently, this is designed like a net which comprises a plurality of apertures 6. The inner of the shoe upper 3 is formed by a sock-like section 9 which surrounds the foot of the wearer.
It is essential that the second material section 5 consists of a plastic material with shape memory effect. With respect to this material already specific explanations are made above.
The mentioned shape memory effect is basing on the fact—as already explained—that shape memory polymers comprise a network structure, wherein the excess of a phase transition goes along with a significant change of the mechanical properties. The above mentioned material Desmopan® DP 2795A SMP fulfils those requirements as a phase segregated block copolymer.
The mentioned material differs from conventional TPU thus by the presence of an additional phase transition. Those phase transitions are used here in applications for shape memory polymers. Thus, a mechanical conditioning is possible at which the material is brought under force into a temporary shape.
A switching temperature between 34° C. and 45° C. is provided at which the crystallisation of the soft segments take place.
In the FIGURE is can be seen that in the sole 2 a battery 7 is arranged. A cable which is shown only schematically is connected with the material of the second material section 5, wherein the material of the second material section 5 can be flowed through by the current from the battery 7 via a switch element 8 (electrical switch). This is reached by the fact that the material of the second material section 5 was made conductive which is possible for example by inclusion of carbon particles into the plastic material. The current which is flowing through the second material section creates the required (but relatively minor) heating of the material because the material is acting as an ohmic resistance; thus, if a current is flowing from the battery through the material of the second material section 5 the material section 5 is heated up. If this takes place up to a temperature above ca. 40° C. (i. e. above the switching temperature) the explained shape memory effect takes place which triggers the tying process.
1 Shoe
2 Sole
3 Shoe upper
4 First material section
5 Second material section
6 Apertures
7 Battery
8 Switch element
9 Sock-like section
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/000158 | 1/30/2016 | WO | 00 |
