ES2914448A1 - Self -limpable screen (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Self -limpable screen that comprises a flexible sheet (1) that acts as a protection barrier, where said sheet (1) is dragged by a lower drum (3) semi -submersed rotating inside a bucket (4) that contains a disinfectant agent, moving in the longitudinal direction of the screen. In a first realization the ends of the sheet (1) flexible are stuck forming a single continuous surface, which additionally slides on a higher drum (2). In a second preferential realization the foil (1) flexible is an open sheet that hangs at its ends of the strings (25) of a pulley system (26) that act its movement, and that slides by guides (23) fixed fixed located on the sides of the screen. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

self-cleaning screen

TECHNICAL SECTOR

The invention, as expressed in the title of the present specification, refers to a protection separating screen for use in facilities with a large influx of people.

More specifically, the partition that is the object of the invention is of the type supported by a lower support resting on the ground that comprises a flexible and transparent screen to prevent interpersonal contact. Additionally, it includes a cleaning mechanism that allows the screen to be disinfected semi-automatically or automatically.

BACKGROUND OF THE INVENTION

Currently, there are various types of screens on the market that act as a protective barrier. In recent months, its use has increased due to the expansion of SARS-CoV-2 in the population. One of the recommended measures to prevent the spread of this virus is social distancing, a recommendation that is difficult to reconcile with the functional needs that occur in offices, schools, health centers, hotels and in general in any other work environment with influx of public.

This has led to the use of physical barriers that prevent direct contact and therefore reduce exposure to the virus, especially when it is not possible to maintain distance between people. These protective partitions have a common limitation, and that is that their cleaning and disinfection must be carried out periodically by manual means (as with any other exposed surface) using disinfectant agents that are chemically compatible with the material.

Due to their barrier function, it must be assumed that these partitions constitute surfaces with a certain probability of being contaminated, a probability that is higher the greater the number of people to whom it is exposed. This fact is particularly relevant in activities such as hospitality and in particular in primary medical care, in which the probability that each user is potentially infectious is also greater. and/or suffer from any pathology that makes them especially sensitive to SARS-CoV-2 infection.

In accordance with the established disinfection protocols, surfaces must be disinfected at least daily if they are in public offices with little interaction, such as pharmacies, tobacconists or banks, or with "fixed" users, such as in schools without changes of address. classroom, offices with permanent posts assigned, etc.

On the other hand, in cases where it cannot be ensured that there has been no accidental contact with the barrier, such as can occur in cafeterias or canteens, and in establishments where the probability of contamination is high or entails a greater risk, such as in medical consultations, these surfaces must be disinfected after each user or group of users.

It is common to observe the application of these disinfection protocols on tables, chairs, or electronic terminals after each use, but not on the separating barriers. This is motivated, in part, because the probability of physical contact with the barrier is assumed to be reduced, an assumption whose goodness depends on the circumstances of each type of use and unfortunately on the user himself, so it may be wrong.

On the other hand, there are practical difficulties when carrying out barrier disinfection activities, such as the time required to do so and the availability of people to perform this function, which further limits its application. For example, it is unimaginable that after each consultation of about fifteen minutes on average, an assistant or the doctor himself dedicates himself to disinfecting the barrier before calling the next patient, especially when he must take extreme precautions to expose himself to potentially contaminated surfaces.

And yet, as has already been indicated, due to its barrier function, it is necessary to assume a high probability that said screens are contaminated.

There are currently solutions on the market that cover the function of a protective screen, but none have been identified that incorporate the feature of being self-cleaning.

Specifically, these partitions can be classified according to their rigidity as totally rigid - made with rigid thermoplastics or tempered glass - or flexible - made with flexible thermoplastics -. Depending on their vertical dimension, there are screens half screen, covering approximately the lower or upper half of a person standing, or full screen, extending from the ground to about 2m high.

On the other hand, the screens can be supported by a lower support, either on the floor or on furniture, or by an upper support, typically hanging from the ceiling. The latter are not portable or have a very limited autonomy, since they require some type of fixed anchorage to the ceiling. They are also not suitable for outdoor use, since in addition to the above limitation is the fact that they require some type of additional anchoring to the ground to prevent them from moving with wind loads, so they are not considered to be of interest.

On the other hand, flexible partitions, whether they have an upper or lower support, have an important limitation: their manual disinfection is laborious and can entail a greater risk, since due to their flexibility it is necessary to clean them by holding them from the opposite surface.

Rigid half-screen barriers with support on furniture usually consist of front or side barriers, without a frame and for uses with short-term interaction or with very little user turnover. Under these conditions of use, taking into account that disinfection can be infrequent (1-2 times a day) and at the same time that the table or counter on which they are located is disinfected, there is no great advantage in incorporating some sort of self-cleaning mechanism.

On the other hand, rigid barriers supported on the ground incorporate some type of frame or metal fence and support legs with and without wheels. From the point of view of their use as a barrier, those with a half screen only have disadvantages compared to the previous ones, since as they are not on another type of element they can be less effective as a barrier. On the other hand, its geometry is more complex and therefore its disinfection is somewhat more laborious, so its commercial offer is of little interest.

However, full screen ground-supported rigid barriers are commonly used for public spaces, such as cafeterias, workshops or offices. Normally, their dimensions vary between 550 and 2,000 mm in width and 1,800 to 2,200 mm in height, and they use translucent screens made of cellular polycarbonate or transparent ones made of polymethylmethacrylate or tempered glass. For this type of partitions, used in environments with a large influx of people, it would be convenient to have a self-cleaning system.

In the document "Disinfectants and disinfection methods against SARS-CoV-2'' prepared by the Department of Hygiene of the National Center for New Technologies, dependent on the National Institute of Safety and Health at Work, a compendium of the technologies is collected. available in terms of disinfection against SARS-CoV-2.

According to this document, no evidence has been found on the efficacy and safety of SARS-CoV-2 disinfection with ultraviolet or ozone radiation devices. Likewise, the Ministry of Health warns that UV-C radiation and ozone cannot be applied in the presence of people.

In accordance with the above, to disinfect these protection barriers, technologies based on UV_C radiation and ozone must be ruled out, since their application is not possible in the presence of people, which would limit their use and simultaneous disinfection.

However, there is evidence that coronaviruses are inactivated on contact with a 0.1% concentration sodium hypochlorite solution, 62-71% ethanol, or 0.5% hydrogen peroxide within one minute.

For the disinfection of this type of screens using virucidal products, the basic principle used is usually used, with hardly any changes in the last century, in the cleaning of other types of rigid and transparent surfaces - such as car windshields - based on a scraper equipped with a flexible tongue that sweeps the surface, dragging away the dirt and cleaning agents used.

However, this type of disinfection presents as a practical difficulty that it is necessary for an operator to carry out the cleaning manually, which entails long operating times, as well as difficult access to the barrier with the cleaning means.

All these limitations make the disinfection of screens even less feasible in spaces where, due to the high turnover of users - as in medical consultations or the hotel industry -, more frequent disinfection is required without this being prevented. the simultaneous use of the protection barrier.

EXPLANATION OF THE INVENTION

The self-cleaning partition of the present invention solves the problems of the previously described state of the art as it provides a self-cleaning and autonomous physical barrier, of the type of full screen with lower support resting on the floor, which allows its semi-automatic or automatic disinfection quickly and effectively, and which maintains or improves the features of the currently existing ones without significantly increasing its cost.

The automatic cleaning system allows uninterrupted use of the barrier, guaranteeing hygienic and safe conditions in the vicinity of the screen regardless of how often people in the vicinity change.

Said self-cleaning screen solves the following technical difficulties inherent to the incorporation of a disinfection process: it is not manual, that is, it does not require the contact of people with the surface to carry out its disinfection; it is fast, that is, it does not require significant time for disinfection and, therefore, it does not interrupt the activity in which the partition is used; it is in situ because it does not require the isolation of the barrier to carry out its disinfection safely for people, as was the case, for example, with ozone-based media or in some types of exposure to UV light; and it is autonomous, since it does not require connection to supplies of any kind (electricity, fluids) to carry out disinfection, allowing its use in any location, forming a portable and autonomous screen.

Additionally, but not least, the self-cleaning partition of the invention does not imply a significant increase in cost, since, in practice, this circumstance would limit its use.

The self-cleaning screen of the present invention provides an effective physical barrier to prevent the droplets that are expelled when speaking, coughing or sneezing from reaching the people close to them. Preferably, it will be made of a transparent material, which allows normal communication between people on both sides of the barrier. Likewise, it will be highly resistant to chemical agents commonly used for disinfection against SARS-CoV-2, such as ethanol solutions (which attack polymethyl methacrylate), sodium hypochlorite solutions (active ingredient of bleach) or soap solutions.

Preferably, it will have good fire resistance properties to prevent its presence from significantly increasing the fire load of a room. For example, the polymethylmethacrylate used in other types of barriers is easily combusted and is not self-extinguishing.

Preferably, the protection barrier will be resistant to UV light and exposure to the elements, and may also have good resistance to impact and cracking (in general, thermoplastics have an impact resistance of 10 to 30 times higher than the of glass).

More specifically, in a first preferred embodiment of the invention, the self-cleaning partition uses a sheet of flexible material as a protective barrier, the ends of which are glued to form a continuous surface, held and driven by two cylindrical drums located at the upper and lower ends of The Frame.

In this way, said continuous sheet forms a double sheet comprising two parallel surfaces that act as independent protection barriers for each of the spaces delimited on both sides of the screen. This arrangement allows that, in the vertical movement of the sheet activated by the rotation of the drums, one of the surfaces of the double sheet rises while the other falls.

In its movement, said sheet slides around the external lateral face of the drums, the lower drum being partially submerged inside a bucket containing water and a disinfectant agent for cleaning it. In the upward movement of the sheet, as it exits the tray, it comes into contact with silicone tabs that sweep its surface and eliminate any excess moisture it may contain.

On the other hand, in a second embodiment of the invention, the self-cleaning screen comprises a flexible sheet open at its ends so as to form a discontinuous surface that is driven by a system of pulleys located in the upper part of the screen. Specifically, said sheet is hung from the belts of the pulley system and moves vertically along fixed guides that are formed on the two sides of the screen.

Likewise, the cleaning system comprises a bucket in which a lower drum is partially immersed, which drags the flexible sheet in its rotation. In this case, the sheet comprises a single surface whose length is equal to the height of the screen, so that, after each cleaning process, said sheet goes from being completely housed inside the guide located on one side of the screen, to be in the guide on the opposite side. Of In this way, a single surface is defined that acts as a protection barrier for the two spaces on each side of the screen.

BRIEF DESCRIPTION OF THE DRAWINGS

To complement the description that is being made and in order to help a better understanding of the characteristics of the invention, a set of drawings is attached to this description, as an integral part thereof, in which with character Illustrative and non-limiting, the following has been represented:

Figure 1.- Shows a perspective view of the first preferred embodiment of the self-cleaning partition, where the flexible sheet comprises a continuous surface.

Figure 2.- Shows an exploded view of the shaft that is housed inside the drum of the screen in figure 1.

Figure 3.- Shows a detailed view of the lower drum of figure 1 semi-submerged in the cleaning bucket.

Figure 4.- Shows the gear system that drives the drums of the partition in figure 1.

Figures 5a and 5b.- Show two possible configurations of the set of internal and external tabs of the screen of the present invention.

Figure 6.- Shows a perspective view of the second preferred embodiment of the self-cleaning partition, where the flexible sheet comprises an open surface.

Figures 7a and 7b.- Show detailed views of the system of pulleys that drive the drum and sheet of the screen in figure 6, where said pulleys are located in a central area and in an upper area of the screen, respectively.

PREFERRED EMBODIMENT OF THE INVENTION

In view of the aforementioned figures, and in accordance with the adopted numbering, it can be observe in them two examples of preferred embodiment of the invention, which comprise the parts and elements that are indicated and described in detail below.

Specifically, in a first preferred embodiment shown in Figure 1, the self-cleaning partition comprises a support structure (5) that encloses a sheet (1) of flexible material that acts as a protection barrier, where the ends of said sheet (1) they are joined to form a continuous surface, held and driven by two cylindrical drums (2,3) located at the upper and lower ends of the screen.

In this way, the continuous sheet (1) forms a double sheet comprising two parallel surfaces separated by the cross section of the cylindrical drums (2, 3), where one of the surfaces acts as a protective barrier for the space comprised a side of the partition, and the other surface acts as a protective barrier for the space on the opposite side of the partition. In its vertical movement, that is in the longitudinal direction of the screen, while one of the surfaces of the double sheet rises driven by the drums (2, 3), the second descends.

This arrangement makes it possible to define an inner face of the flexible sheet (1), oriented towards the inside of the screen, that is towards the space between the two surfaces of the double sheet, and an outer face oriented in the opposite direction, that is towards outside the screen.

The inner face of the flexible sheet (1) is placed in a taut manner on the lateral outer face of the cylindrical drums (2,3), so that, when the drums (2,3) rotate, they print a displacement vertical of the flexible sheet (1), which moves continuously. That is, if the line formed by the ends of the sheet (1) at their junction, arranged transversely to the partition, is established as a reference, said line would move, dragged by the turning movement of the drums (2, 3), in the direction normal to them from the lower drum (3) to the upper drum (2), to then descend and return to the initial position from which it began its movement.

Preferably, to increase the contact surface between the sheet (1) and the drums (2,3), but preventing them from having a lot of weight and inertia, said drums (2,3) are built using hollow aluminum cylinders whose surface is has tried to adjust the adherence of this surface with the flexible sheet (1).

The adjustment between the flexible blade (1) and the drums (2,3) must be adequate to guarantee the correct movement of the blade (1). The most determining factor is the relative adherence between the flexible sheet (1) and the drums (2,3), which is governed by the following factors: the contact interaction between the materials of the elements - drums (2,3) and sheet (1) -in humid conditions, due to the cleaning system, and variable temperature, due to the possibility of placing it outdoors; the existing contact surface between the elements; the tension applied in the assembly of the drums (2,3) that support the flexible sheet (1) and in the assembly of the cleaning system that will be analyzed later; and the precision in the parallelism of the drums (2,3) that print the movement to the blade (1) and the synchronism of its rotation.

On the one hand, insufficient adhesion would make it difficult for the flexible sheet (1) to drag with the rotation of the drums (2,3), a phenomenon that becomes more important if one takes into account the additional resistance offered by the elements that perform the function cleaning. On the other hand, an excessive adherence together with a small parallelism error of the axes (8) of the drums (2,3), would lead to a progressive lateral displacement of the flexible sheet (1) with respect to the axes (8) deforming and disabling the partition in a short time.

Another determining factor for the correct advancement of the flexible sheet (1) is the synchronization of the rotation of the upper (2) and lower (3) drums. For this, preferably but not limiting, a pinion (7)-chain (6) gear system driven from a central shaft (28) has been used. In figure 4 said central shaft (28) can be seen, coupled at one of its ends to a crank (20) through which the rotation of the central shaft (28) is manually activated.

However, in another preferred embodiment not shown in the figures, the rotation of the central axis (28) could be activated automatically through a motorized mechanism, such as through a motor powered by rechargeable batteries, whose drive was controlled remotely or locally. In this way, the cleaning and disinfection of the partition could be activated without the need for a person to turn the crank.

In any case, on the central axis (28) there are two pinions (7) that engage, through two independent chains (6), with two toothed wheels (29) located, respectively, at one end of the axis (8) housed inside the upper drum (2) and at one end of the shaft (8) housed inside the lower drum (3). This mechanism allows the turning movement to be transmitted from the central axis (28) to the drums (2,3), synchronizing their rotation.

When using hollow cylinders, to ensure a good centering of the axis (8) of each drum (2,3), said drums (2,3) are preferably placed at each end, respective heads (9) that incorporate a rigid flange (10) that transmits the movement between the shaft (8) and the drum (2,3) and that is fixed to it by means of an interference fit. That is, a pressure or tightening fit for the union between the shaft (8) and the flange (10), in which the diameter of the shaft (8) is greater than the hole delimited by the flange (10) and the shaft ( 8) is fitted inside, thus preventing the relative movement between both pieces and transmitting the torque from one to the other.

Figure 2 shows a detail of the rigid flange (10), which comprises a series of through holes for the introduction of bolts (11), said bolts (11) allowing the fixing of the flange (10) on the head. (9) through the threading of some nuts (12) that are tightened at the base of the head (9). However, the union between flange (10) and head (9) is not limited to a threaded union, but could be made through other methods such as, for example, a tightening fit.

On the other hand, given that the perfect parallelism of the axes (8) is not constructively attainable and a small parallelism error progressively displaces the blade (1) laterally, it is preferable that the blade (1) slide laterally to correct its position and stay centered. To achieve this behavior, in addition to adjusting the relative adherence between the sheet (1) and the drums (2,3), said drums (2,3) are finished at their ends with curved stops (13) made of a slippery material.

Preferably, the bolts (11) connecting the flange (10) arise from the inner base of the curved stop (13), which comprises two discs of different diameters joined by a curved and inclined lateral surface. This lateral surface allows the sheet (1) to slide over the curved stop (13) and corrects its position. On the other hand, the diameter of the smaller disc coincides with the diameter of the drums (2,3), so that the curved stop (13) perfectly fits the ends of the drums (2,3).

According to this configuration, as can be seen in Figure 2, the shaft (8) housed inside the drums (2,3) passes through the head (9), the rigid flange (10), the curved stop (13) and finally the toothed wheel (29) through which its rotation is activated. Said shaft (8) is fixed to the assembly thanks to the interlocking of a mobile flange (14) inside a hole (27) that comprises the cylinder (15) where the toothed wheel (29) is formed.

The protective screen of the present invention also comprises vertical side profiles that form part of the support structure (5) and that house the previously described pinion (7)-chain (6) gear system inside. Likewise, there are some bearings (24) fixed to the sides of the support structure (5) in which the end of the shaft (8) of the tabors (2,3) is inserted, so that the weight of the assembly is supported by said bearings (24).

On the other hand, the cleaning system of figure 3 comprises three main elements: a bucket (4), an inner tab (16) and an outer tab (17). The bucket (4) is located in the lower part of the screen and contains the cleaning medium inside, which can consist, for example, of a sponge soaked in water and a disinfectant agent. The lower drum (3) is partially submerged in said bucket (4) so that when the sheet (1) slides over the spongy material, it drags any possible dirt that may have been deposited on the surface of the sheet (1) . Additionally, the bucket (4) can incorporate a flexible tube (not shown in the figures) to facilitate its filling and emptying, said tube being easily removable from the assembly to be able to clean the inside of the bucket (4) if necessary.

When the partition needs to be cleaned, the movement of the slat (1) will start by activating the crank (20), which will turn until the slat (1) has returned to its original position, that is, when the entire surface comprising the continuous sheet (1) has been submerged in the tray (4) with disinfectant agent.

The inner tongue (16) is located at a height above the lower drum (3) and extends along the entire width of the sheet (1) preferably in a direction parallel to drums (2,3), that is transverse to the screen. Said inner tongue (16) is in direct and tight contact with the inner face of the flexible sheet (1), so that it pushes and moves said sheet (1) outwards, that is, towards the outside of the screen. The inner tab (16) will preferably be made of silicone, or some other material with equivalent characteristics, so that it is capable of sweeping the inner face of the sheet (1) to remove any traces of moisture that remain on it after disinfection.

For its part, the outer tongue (17) is located at a height above the inner tongue (16), also in the transverse direction of the screen. Where appropriate, the outer tongue (17) is in direct and tight contact with the outer face of the flexible sheet (1), so which pushes and moves said sheet (1) inwards. Similarly, the outer tab (17) sweeps the outer face of the sheet (1) to remove any traces of moisture.

The configuration of the previously described inner (16) and outer (17) tabs, in which a thrust is applied to both faces of the flexible sheet (1), also allows adjusting the tension of said sheet (1) after its assembly on the drums. To facilitate this task, it is preferable to place the tabs (16,17) close to each other.

This last arrangement, in which there is a single inner tongue (16) and a single outer tongue (17) like the one in figure 5a, is designed so that the drive of the drums (2, 3) is always done in the same direction. of rotation, so that the surface of the double sheet that has an upward movement is the one that comes into contact with some tabs (16,17) so that the remains of moisture are dragged downwards towards the tray (4).

However, to be able to operate the mechanism indistinctly with any direction of rotation, it would be necessary to have a double set of tabs (16,17) in contact with both surfaces of the double sheet, such as the one shown in figure 5b, so that Whatever the surface of the double sheet that had the upward movement - taking into account the direction of rotation of the drums (16,17) -, there would always be a tongue (16,17) in its ascent.

Lastly, to close the space between the flexible sheet (1) and the lateral vertical profiles of the support structure (5), additional lateral profiles (19) can be included, arranged between the two surfaces comprising the double sheet and that extend along the height of the screen, oriented in the transverse direction of the screen that close the set preventing gaps that connect both sides of the screen.

On the other hand, in a second embodiment of the invention shown in Figure 6, the self-cleaning screen comprises a support structure (5) that encloses a flexible sheet (1) open at its ends so as to form a discontinuous surface that is actuated by a system of pulleys (26) located in the upper part of the screen. Specifically, said sheet (1) moves vertically along fixed guides (23) that are formed on the sides of the support structure (5) of the screen.

Preferably, the length of said sheet (1) is equal to the height of the partition, so that, contrary to what happened with the double sheet of the first embodiment, said sheet (1) comprises a single surface that acts as a barrier of protection for the two spaces included on both sides of the screen.

The two ends of the open slat (1) comprise two sections that are transverse to the screen (22), that is, along the width of the screen, which are inserted into the side guides (23) and enable the slat to slide ( 1) in the vertical direction. Said transverse profiles (22) hang from belts (25) -preferably made of nylon or another material with equivalent mechanical properties- that are wound around the pulley system (26).

The pulley system (26) comprises two types of pulleys, preferably rubber, as shown in figures 7a and 7b. On the one hand, at both ends of the upper part of the screen, there are some first driven pulleys on which two independent belts (25) slide, from which the two transverse profiles (22) hang respectively, using the same belt (25). ) to hold both ends of said transverse profiles (22), as shown in figure 7b.

In order to synchronize the movement of the two transverse profiles (22), which must move in the longitudinal direction of the partition while maintaining parallelism between them, said driven pulleys are driven by second drive pulleys that are preferably located at a medium height in the side of the screen on a central axis (28), as shown in figure 7a. Said central shaft (28), is in turn coupled to the mechanism that activates the rotation of the assembly which, as in the previous embodiment, can be either a crank (20) or a motorized and automatic system.

Coaxially to said driving pulleys, on one of the sides of the screen, there is also a chain system (6) that engages and activates the rotation of a lower drum (3) of the screen, as shown in the figure 7a. The flexible sheet (1) rests on the lower drum (3), in such a way that it is dragged by it and makes it possible to tighten said sheet (1).

In the same way as in the external embodiment, the lower drum (3) is partially submerged in a bucket (4) that contains the appropriate cleaning means for its use. disinfection. In the vicinity of the lower drum (3) and above it, there is a double set of inner (16) and outer (17) tabs like the one described above.

In this second preferred embodiment, when it is necessary to clean the partition, actuating the crank (20) will cause said sheet to begin its downward movement along the guide (23) located on one of the sides of the partition, while a once dragged by the lower drum (3) and sanitized in the tray (4), it will begin to ascend through the guide (23) located on the opposite side until it reaches the upper part of the screen.

In this way, contrary to what happened in the previous embodiment, since the flexible sheet (1) is open and with a length equal to the height of the screen, not its entire height is occupied by the protection barrier while it is being closed. proceeds to clean the sheet, but hollow spaces are formed as seen in figure 6, which correspond to the moments in which the sheet is partially inserted in the guide (23) on one side, and partially in the guide (23) on the opposite side.

For this same reason, a second set of tabs (16,17) is necessary, since the sheet, after each cleaning process, goes from being completely housed inside the guide (23) located on one side of the screen, to being in the guide (23) on the opposite side. In order to be able to carry said sheet (1) from one side of the screen to the other, it is necessary to activate the lower drum (3) in both directions, for which a double set of tabs (16,17) will be required, like the one in figure 5b so that the sheet always meets a set of tabs (16 or 17) in its upward movement.

Lastly, it should be noted that in both preferred embodiments the self-cleaning partition has a structure at its base that enables it to rest on the ground, which may additionally comprise rolling means (18) for easy transport.

Claims (10)

1. - Self-cleaning screen comprising a support structure (5) that encloses a flexible sheet (1) that acts as a protection barrier, characterized in that it also comprises: - a rotating lower drum (3) submerged at least partially inside a bucket (4) containing a cleaning agent; Y - at least one drive means that moves the flexible sheet (1) in the longitudinal direction of the screen, where said sheet (1) is dragged by the external lateral face of the lower drum (3). 2. - Self-cleaning screen according to claim 1, characterized in that the ends of the flexible sheet (1) are joined to form a single continuous surface. 3. - Self-cleaning screen according to claim 2, characterized in that it further comprises an upper drum (2) that drags the inner face of the continuous sheet (1), said upper drum (2) being parallel to the lower drum (3) and being its turn synchronized. 4. - Self-cleaning screen according to claim 3, characterized in that the drive means comprises a gear system that transmits rotation to the drums (2, 3) from a central axis (28). 5. - Self-cleaning partition according to claim 1, characterized in that the flexible sheet (1) is an open sheet at its ends. 6. - Self-cleaning partition according to claim 5, characterized in that the ends of the flexible sheet (1) comprise transverse profiles (22) to the partition that slide along fixed guides (23) formed on the sides of the structure support (5). 7. - Self-cleaning screen according to claim 6, characterized in that the drive means that moves the sheet (1) comprises a system of pulleys (26) and belts (25), where the transverse profiles (22) hang by their ends of said straps (25). 8. Self-cleaning screen according to any of claims 4 or 7, characterized in that the rotation of the central axis (28) or of the pulley system (26) is activated manually or automatically. 9. Self-cleaning screen according to any of the preceding claims, characterized in that it comprises at least one inner tab (16) and at least one outer tab (17) that sweep the surface of the flexible sheet (1). 10. Self-cleaning screen according to any of the preceding claims, characterized in that the ends of the lower drum (3) comprise a curved stop (13) that corrects and centers the position of the sheet (1).