The present invention relates to the field of electric power production.
In particular, the present invention concerns a floor tile capable of producing electric power.
The continued growth of global power demand has required a continuous development of technology in the field of power production.
In recent years, the need to obtain energy while avoiding producing environmental damage typical of, for example, fossil fuels, has determined the attempt to target research towards possible sources of clean energy production.
Among the many possible solutions, one is based in particular on the exploitation of the piezoelectric effect, that is, the property of some crystalline materials to polarize, generating a potential difference when they are subject to deformation, thus producing an electric current that can be stored and used later.
A possible known way to efficiently exploit piezoelectricity of some materials is to insert them into containers destined to be installed below the flooring of places receiving a high number of visitors.
In this way, people passing over the device guarantee a constant stress of the piezoelectric material, allowing to achieve good results in terms of power production.
However, the systems presented by the known art, also due to the innovative nature of this kind of approach, present a number of issues that make them not enough advantageous in case of large-scale use.
In this context, the technical task underlying the present invention is to propose a floor tile that overcomes at least some of the drawbacks of the known art mentioned above.
In particular, it is an object of the present invention to provide an easy-to- install floor tile, on which maintenance operations are simple to perform, and
allowing to optimize the conversion efficiency of mechanical energy applied to the tile in electric power.
The mentioned technical task and the specified aims are substantially achieved by a floor tile, including the technical specifications set out in one or more of the appended claims.
According to the present invention, provided herein is a floor tile comprising: a plurality of piezoelectric stacks, each of these stacks being realized by overlapping a plurality of piezoelectric elements and a first plurality of elastic insulating spacers interposed between each pair of adjacent piezoelectric elements; a plurality of plastic containers, each one of them designed to contain a corresponding piezoelectric stack; at least one box configured to house at least two plastic containers.
The tile further comprises a body configured to accommodate the at least one box and comprising: an upper surface designed to support a flooring; a pressure transfer element, designed to transform the pressure exerted on the upper surface of said body in a uniform compression of all piezoelectric stacks contained therein; a retaining element of the at least one box, designed to fix the box inside the body; elastic elements designed to promote the release from a compressed configuration to a rest configuration when the pressure exerted on the upper surface of the body is removed; and a lower element closing the body.
The present invention also relates to a kit for the production of an energy- producing floor comprising: a plurality of floor tiles according to the claims of the present invention and at least one battery configured to be electrically connected to the tiles.
Further features and advantages of the present invention will become more apparent from the description of an exemplary, but not exclusive, and therefore non-limiting preferred embodiment of a floor tile, as illustrated in the appended figures, wherein:
- Figure 1 a shows an exploded view of a piezoelectric stack of a floor tile according to a possible embodiment;
- Figure 1 b shows the same assembled stack;
- Figure 2 shows an exploded view of a plastic container of a floor tile according to the present embodiment;
- Figure 3 shows an exploded view of a box of a floor tile according to the present embodiment;
- Figure 4 shows an exploded view of a body according to the present invention;
- Figure 5 shows a section of the assembled tile according to the present invention, wherein it is possible to see its constituent elements inside the same;
- Figure 6a shows a further possible embodiment of a plastic container of a floor tile once assembled;
- Figure 6b shows an exploded view of the component shown in Figure 6a. In Figs. 1 a and 1 b, 1 generally indicates a piezoelectric stack constituting the basic element of the present invention.
The piezoelectric stack is realized by overlapping a plurality of piezoelectric elements 2; in accordance with a preferred embodiment, there are at least five piezoelectric elements 2 made by piezotite® diaphragms and the polarities of piezoelectric elements 2 are electrically connected in parallel. The wiring required to connect the piezoelectric elements 2 of each piezoelectric stack 1 of the floor tile 100 converges into an electronic control element 9 which allows to convert the signal produced by the piezoelectric stack 1 into directly usable electric current, for example by a temperature sensor, a repeater for at least one wireless signal, a pressure sensor, a pedometer, a lighting system, a circuit breaker contained in the tile, or stored in an external battery.
Between each pair of adjacent piezoelectric elements 2 a spacer 3 is inserted, which is made of an elastic and electrically insulating material, preferably silicones, which allows the pressure to be transferred to all piezoelectric elements 2 of the piezoelectric stack 1 without, however, the risk of subjecting it to excessive stress. Its task is, in fact, also to dampen
part of the pressure exerted by allowing the life of the stack to be lengthened.
First spacers 3 are also provided at the ends of the piezoelectric stack; these may have different sizes compared to the first elastic spacers 3 interposed between two adjacent piezoelectric elements 2.
When the piezoelectric stack 1 is subjected to a mechanical deformation, a compression in the case described herein, the piezoelectric elements 2 polarize generating a potential difference that allows the generation of electric power.
According to a possible embodiment, the piezoelectric stack 1 also comprises a plurality of second spacers 4 having an open annular shape, also made with an elastic and electrically insulating material, but more rigid than the first spacers 3.
These second spacers 4 are circumferentially disposed with respect to the other elements constituting the piezoelectric stack 1 so that their first portion encloses at least a part of a respective first spacer and in a second portion at least a part of a respective piezoelectric element 2.
The function of the second spacers 4 is to maximize the deflection of the piezoelectric element 2 during the compression of the stack, thus increasing the energy production, this being possible since each second spacer 4 is configured to support an outer edge of the respective piezoelectric element
In addition, the open annular structure of the second spacers 4 provides a guide for the wiring needed for stack operation.
Preferably, the piezoelectric elements 2, the first spacers 3 and the second spacers 4 have a circular or quadrangular cross-section with the lateral size being greater than the height.
Fig. 1 b shows in detail a piezoelectric stack assembled according to the embodiment comprising the second spacers 4; also shown is the second portion of the second spacer 4 at the base of the stack circumscribing an empty space 5, since there are no further piezoelectric elements 2 below,
which guarantees the space required for the deformation of the piezoelectric elements 2 during the compression of the stack.
The newly defined piezoelectric stack 1 is configured to be inserted into a plastic container 6 of which an exploded view is shown in Fig. 2a.
The plastic container performs the function of isolating the piezoelectric stack from the other tile components; there is also a through hole 7 through which the wiring of the piezoelectric stack 1 can conveniently pass.
In accordance with an alternative embodiment, the plastic container 6 is made by a plurality of small plates 6a, two small plates 6a in the specific example shown in more detail in the appended Figs. 6a, 6b, each having a plurality of passage seats 6b configured to engage a portion of the edge of a respective piezoelectric element 2.
In use, said small plates 6a define the retaining walls for the piezoelectric stack 1 to which they are associated, so as to ensure a stable positioning of the same within the floor tile 100.
Always in accordance with this embodiment, the plastic container 6 further comprises a pressure element 6c having a flat upper portion 6d and a lower portion 6e, realized by means of a plurality of blades suitable for interposing between two adjacent piezoelectric elements 2.
This solution allows both to bind the piezoelectric elements 2 to their edge ends and to optimize the transmission of the pressure uniformly, thus ensuring their correct bending when pressed, thereby optimizing the process of converting mechanical energy into electric power.
The plastic container 6 is in turn configured to be inserted into a box 8, of which an exploded view is shown in Fig. 3, inside which at least two plastic containers 6 may be accommodated, with the corresponding piezoelectric stack 1 .
According to a preferred embodiment, shown in the appended figures by way of non-limiting example, the boxes have a quadrangular base and are configured to accommodate 4 piezoelectric stacks 1 .
The box is divided into compartments by a separator equipped with through holes 10 which are configured to allow the passage of the wiring of each single piezoelectric stack 1 contained in box 8.
Fig. 4 shows an exploded view of a body 1 1 made according to the present invention.
the structure of the body 1 1 comprises an upper surface element 12 configured to support a flooring, for example: parquet, linoleum, carpet, ceramic tiles or other types of tiles.
Also present is a pressure transfer element 13, designed to transform the pressure exerted on the upper surface of said body 1 1 in a uniform compression of all piezoelectric stacks 1 contained therein.
The pressure transfer element consists of two plates 13a and 13b and a connection element 13c. The connection element is configured to connect the pressure transfer element to a
retaining element 14 configured to bind at least one box 8 inside the body
1 1 .
The plate 13b is secured to the connection element 13c and is connected to the plate 13a by means of elastic elements, for example springs.
The structure of the body 1 1 is complemented by a lower element closing the body.
In use, the completely assembled floor tile 100, of which a section is shown in Fig. 5, can take two configurations.
If no pressure is exerted on the tile, it assumes a rest configuration; when, for example, a person is walking on the tile, the exerted pressure determines its passage to a compression configuration in which the piezoelectric elements 2 are deformed mechanically.
This deformation of the piezoelectric elements 2 causes their polarization, generating a potential difference at the ends of the piezoelectric stack 1 , thus producing an electric current.
When the pressure drops because the person has moved, the tile returns to the rest configuration.
The present invention also relates to a kit for the production of an energy- producing floor. The kit comprises a plurality of floor tiles 1 according to the present invention and at least one battery suitable to be electrically connected to the tiles and to accumulate the electric power produced by them.
Optionally, the electric power could be used by actuators that can take advantage of the energy contained in the battery, or even directly produced by the tiles, for their functioning; for instance, a lighting system could be electrically connected to the batteries.
Advantageously, the presence of elastic elements in the body and the mechanical features of the first elastic insulating spacers favour the return of the floor tile 100 from the compression configuration to the rest configuration.
This feature ensures that, after a stress, the floor tile 100 has time to come back to a rest configuration before receiving further stresses, thus maximizing efficiency and reducing the risk that the tile will always stay in the compression configuration if the stresses to which it is subject have an excessively high frequency.
In addition, the shape and size of the body 1 1 can be easily adapted to the type of floor under which its installation is desired. In case a tile flooring is installed, the tile will be made the same size of the flooring tile, whereas in the case of parquet flooring or similar solutions the size of the tile is not influential and can be decided, for example, based on criteria such as ease of transport and of laying.
The particular structural shape of the floor tile 100 according to the present invention further allows for a high modularity of the same, thus guaranteeing a remarkable ease of replacement of the individual components, for example in the event of failure, without necessarily having to replace the whole floor tile 100.