Technical field

The invention concerns the sole of footwear, in particular of sports footwear, preventing slipping on surfaces, in particular in halls and on artificial surfaces.

Background of the invention

From the technical experience, various solutions are known to prevent slipping between the sole and the walking surface. This includes various additional elements like strips, chains, protrusions etc. which can be used in particular in an open terrain. Their disadvantage is the possibility of damage of ^* one of the surfaces and their unsuitability in various games, like basketball, volley-ball, floorball and others, in particular hall games. The same problems with slippery surface can occur m hospitals, sanatoriums, rehabilitation and other similar premises. Insufficient value of the friction coefficient is very often the cause of even serious injuries and health complications .

As well, various designs of footwear sole are known. Such soles have usually high acquisition prise and their utilization is to a high extent limited both by the specific surface and its maintenance, and also by a very narrow assortment. With the exception of expensive types of sports footwear, suitable models are in fact inaccessible for older people, hospitalized people, handicapped children and adults and as well for socially handicapped groups. It is possible to state and prove that even the most expensive, specially slip-safe constructed footwear degrades in the course of time its features on the contact surface and therefore loses a significant part of its utility value and becomes even dangerous due to its slippery- surface. So far, there are no means on the market to recover it at least partially and finally they become a burden also from the ecologic point of view.

Summary of the invention

The above mentioned shortcomings are to a high degree removed by the sole of footwear, in particular of sports footwear, preventing slipping on the surface according to this invention. Its principle is that the sole is provided with at least one cavity filled with liquid consisting of 5 to 90% of weight propan-1 , 2 , 3-triol , 5 to 15% of weight natural bee honey, 2 to 70% of weight starch powder and 8 to 55% of weight water, while on the bottom side the sole is provided with at least one one-way valve for outflow of the liquid out of the cavity.

In the advantageous design the liquid contains 10 to 15% of weight of gel of silicic acid.

The one-way valve is in the advantageous design in the form of a cone the wider side of which is towards the cavity and the narrower part out of the sole. The cavity can be filled with absorptive material. The cavity is with advantage provided with an inflow opening for filling with the liquid. In the advantageous design, two cavities are placed in the front part of the shoe and one in the rear part of the shoe.

Composition of the liquid arranges high adhesion between the shoe sole and the walking surface or the game surface. This prevents slipping and decreases the risk of injury. From the sports point of view, players have a higher stability which influences also their performance and other users benefit from higher safety and savings of funds for purchase of possible new footwear because the described liquid, as mentioned, regenerates most of types of sole materials used for home, hospital and sports purposes.

The above described liquid has, in addition to its utility slip-safe features, one important feature which is its total non-toxicity. Each of the mentioned components is even used in food assortment. Their mutual composition maintains this feature. There are no special requirements as to the storing conditions. The liquid is almost frost-proof. Its application is very simple, the cavity in the sole is filled with- the mentioned liquid and in movement it flows through one-way valves in the form of micro-openings to the surface of the sole. The one-way valves automatically open in flexing the sole and they close again in its unbending. Considering the minimum size of the outflow openings and considering their shape the liquid will outflow only when the shoe is bent and it will slightly dew the shoe surface. Such cavity can also perform the function of a damping element in jumping etc.

Duration of utilization period depends only on the size ¹ of the cavity, the amount of the liquid and the frequency of use. The cavity is with advantage provided with an input opening for filling the liquid so that the footwear with the required slip- safe features can be used in fact during its whole life cycle. The demands for utilization are in fact minimal. Only a minimum thin film must be created on the sole. Accidental spillage of the liquid is treated by mere wiping like with usual water. The cavity can be filled with an absorptive flexible material which allows better regulation of the liquid outflow and at the same time it can serve as a flexible element. In the advantageous design two cavities are placed in the front part of the shoe and one in its rear part.

The price conditions are very advantageous compared to the utility features. None of the components, either their dispersion endangers the environment. The liquid is slightly hydroscopic and its effectiveness falls in years unless it is protected against moisture of the surrounding environment .

Usually the decrease in efficiency is not measurable. Special demands for maintenance and handling with the footwear are negligible and there is not serious reason to protect it for example against children.

Examples of the invention

The example sole of sports footwear preventing slipping is provided in its front part with a cavity filled with the liquid consisting of 30% of weight propan-1 , 2 , 3-triol , 10% of weight natural bee honey, 30% of weight starch powder, 20% of weight water and 10% of weight gel of silicic acid. On the bottom part the sole is provided with one-way valves in the form of cone micro-openings for outflow of the liquid from the cavity. The cavity is filled with absorptive flexible material and it is provided with the input opening for filling with the liquid.

In another design the sole is provided with two cavities placed in the front part of the shoe and one cavity in the rear part of the shoe .

The accurate percentage or another description of the liquid composition in the form of an example can be misleading because the nature of the walking surface must be known, its dirtiness and whether the surface is contaminated with grease. Prevention of slipping on surfaces contaminated with any grease is not included in the subject of the described solution.

After filling the cavity with the liquid, it is closed and does not outflow from the sole. After wearing the shoe and its utilization, it means walking, running, jumping etc., the sole is flexed and the valves open through which the liquid flows in a minimum amount to the sole surface. This results in dewing the sole surface which is enough for prevention of slipping of the shoe on the surface. Cavities can be filled with absorptive flexible material which can with its features, like in particular rigidity and flexibility, improve the overall features of the footwear. The liquid can be added using the input opening.

Industrial use

The footwear sole, in particular of sports footwear, preventing slipping on the surface, according to this technical solution will find utilization in particular for hall sports and sports operated on artificial surfaces. At the same time, it can be used in other sports halls, hospital and sanatorium premises etc.