Self-cleaning device for applying material between the grout lines of tiles Description Field of the invention The present invention relates to the field of the production of devices which apply plaster material between the tiles and which remove the excess plaster left on the surface of the tiles after application. Even more specifically, an electromechanical device is disclosed for spreading material such as acrylic, silicone and/or mortar between the grout lines of tiles at a speed greater than that which can be obtained with the manual methods used in the art. Prior art The tiles are typically held in place by cementitious material, also known as plaster or mortar, or other suitable adhesives, such as epoxy resin, putty and the like. Liquid mortar is a non- adhesive material that is applied between tiles to fill the gaps between adjacent tiles. This mortar typically comprises a mixture of water, cement, sand and may further include a colored tint and/or fine gravel. It is applied as a thick liquid and hardens over time, identical to the mortar. Mortar is not flexible and cannot expand and contract with varying temperatures. To allow sufficient time for the adhesive to set, the mortar is usually applied at least fourteen to sixteen hours after the tiles have set. Furthermore, excess plaster must be removed as soon as application is complete, as it is very difficult to remove excess plaster from the surface of the tiles once it has dried. The most common procedure used to remove this excess plaster from the surface of the tiles is to manually sponge the excess material, as it is applied, with a wet sponge; a procedure that is laborious and time consuming. During this procedure, the operator is forced to work for most of the time by distributing all his/her weight all over his/her knees, exacerbating the development, over time, of probable occupational diseases, such as bursitis. Other procedures and tools are known to be used to remove excess mortar from the surface of the floor tiles. A common flathead screwdriver has also been used to scrape the mortar off the tile surfaces. However, this method has drawbacks. Due to the small flat area provided on the tip of the conventional screwdriver, only a small amount of excess plaster can be removed at a time. Another tool commonly used has a handle and shaft similar to that of a screwdriver, but which ends at its distal end with a triangular shaped metal scraper head. The end edge of the blade and the corners of the triangle are useful in removing the concrete. In recent years, machinery has been developed that has limited these problems. An example is provided by patent application US10364580B1 to RUDY AMMED BONACHEA RUIZ. The patent claims a mortar installation device having a mortar application element and a mortar removal element at the back of the mortar application element. The mortar application element includes a mortar tank for storing mortar and a mortar dispensing head which rests against an area of a tiled surface, and applies mortar in the spaces between the tiles. The mortar application element may include a user operable piston to push the mortar from the mortar tank to the mortar dispensing head. The mortar dispensing head may include a rear floor wiper to scrape and sweep excess mortar forward from the restricted area of the tiled surface. The mortar removing element removes excess mortar from the tile surface. Another example is that of patent application US5807022A to MICHAEL D. MCCLEARY. The patent claims a device for spreading mortar and plaster for floor tiles, orientable and combined to apply the adhesive material at a predetermined thickness. The device comprises a telescopically adjustable rectangular frame having a leading edge and a trailing edge, and a pair of sides for containing the adhesive material. The rectangular frame is telescopically adjustable in various widths and can be fixed to a particular width depending on the size of the tile for the given installation. The rear edge of the device incorporates a downwardly extending trowel blade, resiliently mounted and having an edge with a sawtooth or square tooth shape. The trowel blade is adjustable so that the device can be used to spread various thicknesses of adhesive material. The material is spread by sliding the device over the tile surface so that the rear edge spatula distributes the adhesive material evenly. Despite these technical advances and the resolution of some problems, these devices are not only expensive, but also very bulky, subject to laborious maintenance, due to the many internal components that are difficult to reach, and above all they do not fully exploit the technologies available on the market today. The object of the present invention is to propose a device which not only provides for exponentially speeding up the operations of spreading the mortar between the tiles, but in the same way to safeguard the operator’s health by offering him/her an intuitive and comfortable tool to use. Many of the components are replaceable and easily accessible/removable, and due to the presence of state-of-the-art sensors, the precision of the tool allows very high results to be achieved. Description of the invention According to the present invention, an innovative electromechanical device is provided for spreading and shaping in a practical and precise manner material of acrylic, silicone and/or soft cementitious paste type in order to create grout lines, joints or mortar. The device advantageously speeds up all the laying operations compared to what can be obtained with the manual methods used in the art, including cleaning the excess product dispensed, minimizing the effort made by the operator and safeguarding him/her from any occupational pathologies, such as bursitis: this pathology is very common especially in operators who spend considerable time bent over and resting on their knees, a position required by the common art for working the grout lines of tiles. The device is composed of a rectangular frame in which a drive wheel is engaged and fixed at the center, which allows the invention to move along a surface. By virtue of a regulator, engaged on the surface of the frame and connected to the drive wheel, it is possible to adjust the height of the frame with respect to the surface, according to the customer's needs. The drive wheel is pushed through a telescopic rod, the lower end whereof is connected to a ratchet gear system: the latter, installed on said drive wheel, allows the device to have only a forward motion. In one of the preferred embodiments thereof, the telescopic rod comprises a button which acts on the connection with the ratchet gear system, in such a way as to activate/deactivate the free motion, forwards and backwards, of the device; moreover, the telescopic rod can be extracted at any time from said ratchet gear system, allowing the operator to rest the device at the base of vertical surfaces in order to carry out operations, such as creating joints on the door profile covers. The drive wheel can advantageously provide a shock-absorbing system, which allows the operations to be made precise even on uneven surfaces. The device according to the invention has a small support wheel, engaged in the rear part of said frame and near said drive wheel, which allows canceling effects such as rolling and pitch, said small support wheel advantageously is height adjustable by means of a threaded spring regulator. Preferably, the stability of the device is further ensured by guides with wheels, engaged at the ends of the lower surface of said frame and placed in contact with the surface. The laying and processing operations between the grout lines of the tiles are guaranteed by a nozzle package consisting of: x an orientable dispenser; x a nebulizer of the liquid; x a spatula; x a hydrated microfiber roller; and x a secondary spatula for cleaning the roller. All the electrical components of the nozzle package, and of the invention in general, are advantageously regulated by an internal microcontroller, connected to them by means of wiring. All adjustments are accessible by the user via a keypad installed on the surface of the frame. Specifically, the orientable dispenser, installed, facing downwards, in the front part of the lower surface of the frame, is connected to a tank, installed in the immediate vicinity, which by virtue of an electric motor and a piston compresses the product, so that it emerges from its cartridge, previously loaded on the device, as said product is dispensed from the orientable dispenser. In one of the preferred embodiments, the invention provides a laser pointer, engaged on said orientable dispenser, which allows the user to receive clear information regarding the exact orientation of the orientable dispenser during use; moreover, the present device can advantageously provide a rotation sensor, installed near the drive wheel, which collects data regarding the speed assumed by the drive wheel and sends these to the microcontroller, making the delivery flow constant with respect to the speed of the drive wheel itself. The nebulizer of the liquid, engaged behind said orientable dispenser, nebulizes, through an electric pump, the previously dispensed product, in such a way as to make its spreading and following cleaning thereof effective: the nebulizer of the liquid is also connected to a secondary tank, engaged in the immediate vicinity, which contains the liquids to be nebulized. By virtue of a spatula, engaged in the lower surface of the frame and behind the nebulizer of the liquid, the device advantageously spreads the previously dispensed product inside the grout lines of the tiles as it is moved forward. The spatula is preferably of the replaceable type and adjustable according to the customer's needs, in such a way as to adapt and work perfectly on all surfaces. The microfiber pulley roller, also engaged in the lower part of the frame but above all in close contact with the rear part of said spatula, is made to rotate by said drive wheel by means of a rubber belt: in this way, thanks to the rotation assumed, it not only constantly cleans said spatula, but also allows the device to clean the surface of the product dispensed in excess, escaping from the grout lines. Furthermore, the rubber belt advantageously works, by means of a guide system, in a crossed manner, allowing the microfiber pulley roller to rotate at a speed greater than that assumed by the drive wheel. The cleaning of the microfiber pulley roller is guaranteed on the one hand by a secondary nebulizer, engaged inside the frame and connected to the secondary tank, which makes it constantly hydrated, and on the other hand by a secondary spatula, engaged on the rear in close contact with it, which exploiting the direct contact and rotation assumed by the roller removes the product attached thereto. In one of the preferred embodiments thereof, the present invention may comprise an air bubble level, engaged on the upper surface of the frame, suitable to allow the horizontality and the verticality assumed by the device during its use to be controlled. Finally, the device can advantageously comprise a micro-video camera, engaged in the lower part of the frame, adapted to capture the images during use: said micro-video camera can be connected, via network and/or Bluetooth, to any mobile device; in this way, the user can have access to all the captured images and view, in real time, the correct functioning of the device. The advantages offered by the present invention are clear in the light of the above description and will be even clearer from the accompanying figures and the related detailed description. Description of the figures The invention will hereinafter be described in at least a preferred embodiment thereof by way of non-limiting example with the aid of the accompanying figures, in which: - FIGURE 1 shows a side view of a self-cleaning device for applying material between the grout lines of tiles 100 according to the present patent application; - FIGURE 2 shows a bottom view of the components of a self-cleaning device for applying material between the grout lines of tiles 100 according to the present patent application; - FIGURE 3 shows a top view of a horizontal section of a self-cleaning device for applying material between the grout lines of tiles 100 according to the present patent application. Detailed description of the invention The present invention will now be described purely by way of non-limiting or binding example with the aid of the figures, which illustrate some embodiments relative to the present inventive concept. With reference to FIGS.1, 2 and 3, the main components of a self-cleaning device for applying material between the grout lines of tiles 100 according to the present patent application are shown. In particular, FIG. 1 shows a side view of a self-cleaning device for applying material between the grout lines of tiles 100, showing some internal components in broken lines; FIG. 2 shows a bottom view of some components belonging to the self-cleaning device for applying material between the grout lines of tiles 100; FIG. 3 shows a horizontal section of the internal components of the frame 11. The invention consists of a frame 11, with rectangular form, adapted to contain, maintain quite stable/firm and protect the internal components of the invention; Inside said frame 11, precisely in the median part of the lower surface, a drive wheel 12 is engaged, adapted to be moved by the user by means of a telescopic rod 10, allowing the movement of the invention along a surface. By virtue of a regulator 25, engaged on the surface and connected to said drive wheel 12, it is possible to adjust the height of said frame 11 with respect to the surface. Said telescopic rod 10, engaged in the center of said frame 11, allows the user to move the invention comfortably and with minimum effort: the lower end is connected to said drive wheel 12 by means of a ratchet gear system 13, such as to allow the invention to assume only a forward motion; by means of a push button 16, adapted to move the connection of said telescopic rod 10 with said ratchet gear system 13, it is possible to activate/deactivate the free motion, forwards and backwards, of the device 100. The invention comprises a small support wheel 14, engaged in the rear part of said frame 11 near said drive wheel 12, capable of canceling effects such as rolling and pitch; said small support wheel 14 is height adjustable by means of a threaded spring regulator 24. To improve the stability of the invention, two guides with wheels 15 are engaged at the ends of one of the long sides of the lower surface of said frame 11: by means of contact with the surface, they provide further precision during the use of the device 100. The dispensing of the product 200 and its processing are performed by a series of components described below. The dispensing of the product 200 to be inserted inside the space between the tiles is ensured by an orientable dispenser 17, by means of an electric motor. Said orientable dispenser 17 is connected to a tank 27, installed in the immediate vicinity, adapted to contain said product 200 to be dispensed, and being provided with an electric motor and a piston, it compresses said product 200, so that it comes out of its cartridge, as said product is dispensed through said orientable dispenser 17. A nebulizer of the liquid 18, engaged in the lower part of said frame 11 behind said orientable dispenser 17, nebulizes, by means of an electric pump, the previously dispensed product 200, in such a way as to make its application and subsequent cleaning effective. The nebulizer of the liquid 18 is also connected to a secondary tank 28, engaged in the immediate vicinity and within the frame 11, adapted to contain the liquids to be nebulized. Said tank 27 and said tank 28 each comprise a capacity sensor adapted to activate LEDs 22- 23, engaged on the surface of the frame 11, when the product 200 and/or the liquids have terminated. By means of a door 21, engaged in the upper part of said frame 11, both tanks 27- 28 can be removed, in such a way as to allow constant cleaning and maintenance thereof. The invention provides a spatula 19, engaged in the lower surface of said frame 11 and behind the nebulizer of the liquid 18, which performs the function of spreading the previously dispensed product 200 inside the grout lines of the tiles. The spatula 19 is replaceable and adjustable according to the customer's needs. A microfiber pulley roller is engaged in close contact with the rear part of said spatula 19 and is adapted to be moved by the drive wheel 12 by means of a rubber belt 30, in such a way as to constantly clean and at the same time both said spatula 19 and the surface from said product 200 dispensed in excess, outside the grout lines: said rubber belt 30 is engaged inside said frame 11, and works in a cross manner by means of a system of guides 26, in such a way that the microfiber pulley roller 20 rotates at a speed greater than that assumed by the drive wheel 12. The microfiber pulley roller 20 is, in turn, constantly clean, by virtue of the hydration obtained from a secondary nebulizer 29, connected to said secondary tank 28, and by virtue of a secondary spatula 31, engaged at the rear and in close contact with said microfiber pulley roller 20: the secondary spatula 31, exploiting the direct contact and rotation assumed by said microfiber roller pulley 20, removes the previously removed attached product 200. Finally, a microcontroller 33, installed inside said frame 11, regulates all the electrical components of the invention by means of wiring, in such a way that said orientable dispenser 17, said nebulizer of the liquid 18, said spatula 19 and said microfiber pulley roller 20 support the motion of said drive wheel 12. All the functions and adjustments provided by the microcontroller 33 are accessible by means of a keypad 32 connected to it, installed on the upper surface of said frame 11. Finally, it is clear that modifications, additions or variants may be made to the invention described thus far which are obvious to a man skilled in the art, without departing from the scope of protection that is provided by the appended claims.