Patent ID: 12185890

DETAILED DESCRIPTION

FIGS.1and2show schematically a mobile disinfection device200according to an embodiment of the invention. The device is divided into two main sections: (i) a lower portion202comprising a disinfection chamber203and associated hardware and (ii) an upper cabin204carrying auxiliary components, such as battery214etc. The disinfection chamber203is conveyed along a surface236to be disinfected by a propulsion system228(FIG.9) while preventing radiation leakage through the wall of the disinfection chamber203, which is formed of a material that is impervious to the radiation and acts as a peripheral shielding207.

The disinfection chamber203defines a closed upper end205, an open lower end206(FIGS.4and5) and a surrounding wall207having opposing front and rear portions and opposing side portions. Respective lower front, rear and side edges of the wall207are supported by the propulsion system above the surface to be disinfected, typically leaving a slight air gap so as to reduce frictional contact between the disinfection chamber203and the surface236. One or more radiation sources260are mounted inside the disinfection chamber for irradiating the surface236through the open lower end206. For effective disinfection, UV radiation is commonly used and it is then necessary either to disable the radiation source in the presence of people as is commonly done in known systems; or to prevent leakage of the UV radiation so that the device can still be used even when people are located in close proximity to the device.

To this end, the wall207of the disinfection chamber defines a peripheral shield that is impervious to the radiation and the propulsion system228is configured to obstruct radiation that might otherwise escape from inside the disinfection chamber at the lower edges of the wall207. The propulsion system228may comprise a pair of mutually parallel front and rear rollers232whose respective outer surfaces are configured to obstruct radiation that might otherwise escape from inside the disinfection chamber. The propulsion system further comprises a pair of belts233, each overlapping the front and rear rollers at opposite ends thereof and configured to obstruct radiation that might otherwise escape from inside the disinfection chamber. The propulsion system is configured to drive the belts so as to convey the device along the surface while inhibiting radiation leakage through any gaps that may form between the surface and the lower edge of the disinfection chamber.

These features are seen more clearly inFIGS.17A and17B, which actually show schematically side and end elevations of the device according to a different embodiment described below with reference toFIG.12, wherein the disinfection chamber includes a main outer chamber and an auxiliary inner chamber to provide additional sealing. However, the manner in which the propulsion system blocks radiation is the same for both embodiments. Thus, referring toFIG.17Aand ignoring for the time-being the inner chamber300shown in dotted outline, it is seen that the propulsion system228raises the lower edge of the disinfection chamber slightly above the surface236thereby forming an air gap231, through which radiation could conceivably leak and expose a person nearby. However, the outer surface of the roller serves as an obstruction to such radiation thereby preventing or at least very significantly reducing radiation leakage in the direction of travel of the device. Likewise,FIG.17Bshows that the belts233serve as an obstruction to radiation that might otherwise leak through the air gap231between the surface236and the lower side edges of the disinfection chamber.

The size of the air gap231will, of course, depend on the diameter of the rollers232and the height from the lower edge of the disinfection chamber where their shafts are located. In preferred embodiments, the geometry is such that a small air gap persists so that when the device travels, the lower edges of the disinfection chamber are raised above the surface so as to avoid frictional contact and thus facilitate motion of the device. But the invention does not belie the possibility that the rollers are dimensioned and located to leave substantially no gap. Even in such case, bumps along the surface being disinfected can cause the device to tilt, thereby creating a gap between the surface and at least one lower edge of the disinfection chamber. However, also in this case, radiation leakage will be obstructed by the outer surface of the rollers and belts.

Reverting toFIGS.1and2, it is seen albeit only schematically that the peripheral shielding207constituted by the side wall of the disinfection chamber203has adjustable sealing lips215at its lower edge that create a dark and captured space234with the surface236carrying the device. The sealing lips215are adjustable by a controller237so as to effect minimal frictional contact with the surface236while effectively closing the gap between the surface and the lower edge of the sidewall of the disinfection chamber, thereby preventing leakage of UV radiation. The meaning of “dark” for this description is that no UV light is scattered out and no visible light penetrates therein. At least one closed-loop vacuum dust cleaning unit242is carried by the cabin204and has air inlet(s)244and air outlet(s)246openings (also shown inFIG.9) interfacing with the captured space234. The vacuum unit242has at least one air blower248driven by an electric motor250. InFIG.1, the controller237is shown schematically coupled to the UV source electronics212, but it will be appreciated that other components such as the air blower248and the electric motor250are also controlled by the controller237. The blower248circulates, in a closed loop, air sucked from the captured space234through the inlet opening(s)244via cyclonic dust separator(s)252(also inFIG.7) and via a heat exchange section217and discharges the air back into the captured space234via air outlet opening(s)246. The captured space234is isolated from the surrounding by the peripheral shielding (FIG.9) to avoid scattering of the UV radiation262and to control the air leakage, from the captured space234to the surrounding of the device, of the discharged air coming from the outlet246.

The heat exchange section217transfers the heat218generated by the device elements, such as motors208and250, drivers210, battery214, UV source electronics212and possibly any other heat source onboard the device to the circulating air in order to increase the air temperature and to facilitate moisture removal from the surface236.

It should be clear that the heat exchange section217in aFIG.1is for illustration purpose only—this section may be concentrated at a single location, as shown in aFIG.1, or it may by split to a number of locations along the airflow path. When the heat exchanger is split, the possible heat exchange locations may be, but are not limited to: at the motor250body by heat exchanging fins (the motor must be positioned inline the airflow, as shown inFIG.1); at the cyclonic separator252envelope which has a significant heat exchange area with the airflow inside the cyclone (for this, the cyclone body should be formed from a conductive material such as metal); at the disinfection chamber203which most probably will be a convenient place for many of the heat-generating components in the device, as it shown inFIGS.3to9; near the UV source260, by directing the discharged air via the UV source260.

The need to convey the heat energy of the device200and its components to the circulating air, and to facilitate moisture removal from the surface236, also requires preventing undesired thermal transfer from the device200and its components to the surrounding. This can be achieved by applying thermal insulation (not shown) to the device200and to its external components. Commercial thermal insulation solutions are well-known and therefore not described in further detail. The thermal insulation may also be configured to suppress the noise signature of the device in order to minimize disturbance to humans in the vicinity of the device (e.g. in hospitals and public facilities).

It should be noted that the UV radiation source260in combination with ongoing energy recirculation by utilizing the heat exchange section217, in its concentrated or split form, and by applying the thermal isolation as stated above, may create a combined attack effect of UV and extreme temperature rise that may, together, increase the probability of killing microorganisms.

Another derivable feature of recirculating the heat energy218of the device200and applying the thermal isolation as stated above is a reduction in noise signature. This feature is especially significant in the presence of humans, as may happen in public facilities (e.g. hospitals).

In order to control the air temperature and leakage direction via the lips215, the vacuum unit242is configured to direct some of the after-cyclone(s)252air into the bleeding air discharge264sub-channel (also inFIG.3). This allows controlling the air temperature inside the captured space234at the desired level and retaining the air pressure inside the captured space234lower than the surrounding pressure. The bleeding air discharge264may be controlled, preferably, by an air blower266driven by an electric motor268and controlled by the controller237, or simply by the size of the discharge pipe nozzle270. The size of the discharge pipe nozzle270may be fixed or variable (not shown).

In order to ensure that the bleeding channel air is free of any kind of contaminations, the bleeding air discharge264outlet may be at least indirectly connected to a UV disinfection chamber272(inFIG.1only), thus ensuring bleeding air disinfection by a secondary UV source274prior to final discharge into the surrounding atmosphere.

In order to further clarify the safety mechanism principles, a simplified schematic of the mechanism is illustrated inFIG.2. To monitor the scattering UV radiation262escaping from the captured space234via the sealing lips215to the surrounding atmosphere, at least one light sensor280is coupled to the interior structure of the captured space234to monitor the visible spectrum external light penetrating into the captured space234via the peripheral shielding207and its lips215. This at least one light sensor280is connected to the controller237and is configured to sense light in the visible spectrum that penetrates into the captured space234from the surrounding. At normal operational conditions, when the sealing lips215of the peripheral shielding207contact the surface236tightly, the inside of the captured space234should be completely dark and the light sensor(s)280should indicate near zero visible light spectrum energy. It may be assumed that visible light penetration from outside the device200into the captured space234is generally proportional to UV radiation scattering from the captured space234via the peripheral shielding207and via its sealing lips215to the surrounding. To support light sensor280functionality in dark or near dark environments, visible spectrum light sources (e.g. LED or bulb)282can be attached to the exterior of the device200envelope to provide supplementary light energy222in order to reduce the dependency on external light conditions. Alternatively, infrared light may be used and therefore within the context of the invention and the appended claims wherever the term “visible” is used in association with “visible light” or “visible spectrum” it is to be understood that this includes infrared. The light sensor280and the supplementary visible spectrum light sources282are interfaced to the controller237of the device200to control the UV source260power and to turn off the radiation source260, whenever predetermined safety criteria are achieved. Another safety mechanism to provide redundant safety level is at least one angle sensor (not shown), configured to determine an angle of the device relative to the surface236and to provide an indication for steep angular gradient which may be evidence of external physical intervention.

The device200ofFIG.1may be driven over a variety of surfaces236, having either horizontal or vertical orientations or indeed inclined to the horizontal, by an arm (artificial or propelled by human), or by a propulsion system that includes integral mobile sealing elements, such as a pair of rollers232, both capable of sealing the gap between the sealing lips215and the surface236, and, whenever the latter is not contacting the sealing lips215, to propel the device over the, typically horizontal, surface236. As shown inFIGS.3to9and17A and17Band described above, the mobile sealing elements may also be tracks230, comprising belts233, wheels (FIG.13B) and shielding.

Utilizing the tracks230and the rollers232may allow replacing the simplified sealing lips215, illustrated inFIGS.1and2, by self-disinfecting elements. Self-disinfection is highly desirable to avoid transmission of microorganisms from the surface236to other areas of the building. During movement and operation of the device200, the tracks230and rollers232contact surfaces (FIG.6), and after being in contact with the surface236, are periodically exposed to the UV source260radiation. This periodic irradiation disinfects the tracks230and rollers232on the move.

The structure of the tracks230and rollers232is labyrinth-like, thus serving two main functions: a) to propel the device, b) while propelling, to prevent UV radiation262scattering out of the captured space234.

To allow the track propulsion functionality, including sufficient traction and steering, the main weight of the device200should be carried by the tracks230. This implies that the weight of the device carried by the rollers232should be significantly lower than that carried by the tracks230. To achieve this functionality, the rollers232should be formed from either an elastic material, capable of deforming and increasing the traction over the tracks230, or should comprise a flexible and dense brush226, as schematically shown in aFIG.3B. The second alternative allows scraping the surface236by the brush226while blocking UV radiation and preventing it scattering out.

In order to avoid transferring microorganisms via the tracks230and rollers232, as may be required in some demanding hospital scenarios, the tracks230and rollers232can be decoupled from the surface236by secondary propulsion wheels290having a lowering mechanism292(FIG.6). To stabilize the device200, two additional free wheels294are implemented (FIGS.4and6).

The controller237is configured to control the cleaning and the disinfection process, in the following way: a) driving the UV source260at a sufficiently high power; b) driving the propulsion motors208at a speed allowing the device to radiate a sufficient amount of UV energy per unit of area to destroy the microorganism colonies over the surface; c) running the air blower motor250of the vacuum unit at a sufficient speed to achieve sufficient dirt and dust particles separation and to heat up the circulated air, utilizing the heat exchange section217, by the heat sources, to raise the air temperature sufficiently to ensure moisture removal from the surface236and to facilitate destruction of the microorganisms; d) continuously monitoring by the visible spectrum light sensor280the visible spectrum light energy penetrating into the captured space from the surrounding, including from the supplementary light sources282, to estimate the UV radiation262scattering out from the captured space and switching off the UV source260whenever the estimated value is beyond the safety criteria, or adjusting the power of the UV source260to a lower level; e) continuously monitoring the circulating air temperature and changing the bleeding air airflow by adjusting the speed of the bleeding air motor268or by changing the size of the discharge pipe nozzle270.

It should be stated that the driving of the UV radiation source260and of the propulsion motors208may be done simultaneously, or at different times, based on a ‘move and stop’ principle, at which the UV radiation is applied only when stopped and there is no UV radiation on the move.

Whenever a ‘move and stop’ principle is implemented, a reciprocal self-disinfecting sealing lip mechanism284, shown in aFIG.10, can be implemented. The reciprocal self-disinfecting mechanism284allows sealing the treated surface236area at the ‘stop’ and then disinfecting the contact lines of the lips215by the UV source260, while the sealing contact is created by the self-disinfecting material285(e.g. copper or brass) and the surface236(FIG.10B). The structure of the sealing lips215in this embodiment is of a foldable sleeve activated by an actuator286. The contact line of the foldable sleeve is changed by motion of the actuator286. A closed actuator (FIG.10B) exposes the self-disinfecting material285toward the surface236. An open actuator (FIG.10A) exposes non self-disinfecting material215toward the surface236.

It should also be noted that the amount of UV radiation energy262deployed over the microorganisms on the surface236is practically unlimited, as it is a direct derivative of the UV radiation power and the propulsion speed, which can vary from zero for extremely high UV energy, to a higher propulsion speed for a moderate UV energy.

It should be also stated that the same principle applies to the thermal energy recycling: the amount of thermal energy over the microorganisms on the surface236is practically unlimited, as it is a direct derivative of the recycled power of the device200and the propulsion speed, which can vary from a zero for extremely high thermal energy, to a higher propulsion speed for moderate thermal energy.

It should be also noted that the device200can be autonomous or manually operated.

Whenever the device200is autonomous, the mapping sensors265(FIG.3A) on the top of the device200are configured to indicate the distance to the object ahead of the device and a camera267(FIG.3A) is configured to identify the object. The device200may also be equipped with hazard sensors (not shown) to indicate obstacles such as stairs and means responsive thereto for stopping the device.

The abovementioned sensors should not be considered as limiting the potential autonomous applications based on the present invention. Other sensor technologies may be integrated to provide a higher level of autonomous performance.

The device200may be equipped with a charging module and interface (not shown) for interfacing to an external recharging unit (not shown) configured to recharge the battery214. The recharging unit is configured to provide power to the battery214either by wires, or wirelessly or a combination thereof. When recharging over wires, the recharging unit provides power via conductive connectors (not shown). The device200comprises at least one conductive receptor that is configured, when in electrical communication with at least one of the conductive connectors, to provide power to the battery214of the device.

It should be noted that the UV source260can be selected from a group consisting of: bulbs or LEDs and any combination thereof.

It should be also noted that an alternative for switching off the UV source260(which may shorten the bulb life) is to employ a mechanical shutter mechanism276shown inFIGS.5,6and9.

The method of cleaning and disinfection proceeds in a manner very similar to that disclosed above. This method is presented by aFIG.11and includes: a) driving the UV source260at a sufficient high power; b) driving the propulsion motors208at the speed allowing the device to radiate a sufficient amount of UV energy per unit of area to destroy the microorganism colonies over the surface; c) running the air blower motor250of the vacuum unit242at a sufficient speed to achieve sufficient dirt and dust particles separation and to heat up the circulated air, utilizing the heat exchange section217, by the heat sources, to a temperature sufficient to ensure moisture removal from the surface236and to increase the probability of killing microorganisms; d) continuously monitoring by the visible spectrum light sensor280the visible spectrum light energy penetrating into the captured space from the surrounding, including from the supplementary light sources282, to predict the UV radiation scatter262from the captured space out and switching the UV source260off whenever the prediction is beyond the safety criteria, or adjusting the UV source260power to a lower level; e) continuously monitoring the circulating air temperature and changing the bleeding air airflow by adjusting the bleeding air motor268speed or by changing the size of the discharge pipe nozzle270.

The method, as described above, may be implemented simultaneously when the device is moving and attacking the microorganisms on the move, or when the device moves, stops and attacks. The main difference between the two approaches is the rate of disinfection, which is higher when implemented simultaneously.

To enhance the safety level of the system, an additional, second, UV barrier shown inFIGS.12,17A and17Bis established by an auxiliary inner chamber300contained inside the disinfection chamber203. The inner chamber300is in the form of an upside down box, whose open end is close to the surface236, thus minimizing the UV radiation escaping beneath the lower edge of the inner chamber. The radiation sources are, of course, now supported within the inner chamber300, which thus strictly speaking constitutes the disinfection chamber. However, the disinfection chamber may also be regarded as a double walled chamber having inner and outer portions. When the propulsion system228includes tracks having continuous belts of the kind employed by vehicles such as bulldozers, the outer chamber will most conveniently be of rectangular cross-section. But this does not dictate that the inner chamber300be of rectangular cross-section since it may be cylindrical or any other shape without impeding its functionality. To reduce UV radiation scattering escaping through the bottom edge, adjustable lips304control the gap between the chamber300and the surface236. The gap can be adjusted by the air flow supplied via the air outlet of the vacuum unit242. The higher the air flow, the higher will be the pressure gradient over both the internal and external sides of the lips304and the larger will be the gap. To control the gap in a closed loop, one or more UV light sensors308can be placed in the space between the inner chamber300and the outer chamber203. The sensors308feed UV radiation measurements to the controller237, which sets the vacuum cleaner air blower motor (shown as250FIG.1) to a sufficient speed to increase or decrease the gap. By controlling the gap, frictional forces between the adjustable lips304and the surface236may be reduced or even eliminated. The air discharged via the outlets opening246is exposed to the radiation of UV sources260, thus facilitating disinfection of the air prior to its discharge out of the inner chamber300.

As seen for example inFIG.17A, the radiation escaping the inner chamber300via the gap will enter the outer chamber203and be blocked by the rollers232and the tracks230. To assure good contact between the tracks230and the surface236, a floating track-barrier mechanism310is employed. Unlike in typical tracks designed to distribute platform weight over a track contact area, in the floating tracks310some of the platform weight is transferred to the driving wheels312, left and right (FIG.13B), and some to the free wheel314, thus providing the system propulsion based on tri-wheel principle—two driving wheels312and one free wheel314.

To allow measurement of the system motion vector, distance and direction, the free wheel314is equipped with a magnetic pick-up sensor316(FIG.13A) which counts the number of exposures of the sensor316to metal pins318integrated inside the free wheel314. The number of exposures is proportional to the distance that the free-wheel314moves over the surface236. The direction of the free-wheel314is continuously measured by an encoder320integrated into the mounting assembly of the free-wheel314(FIG.13A). Driving wheels312(FIG.13B) are coupled to a belt pulley322, which is driven via a belt324by another belt pulley attached to the shaft of a motor208. As shown inFIG.13C, the roller232may carry flexible sealing strips330capable of creating, simultaneously, at least two sealing lines with the surface236, thus compensating for roughness and non-planarity of the surface236.FIG.13Dshows a similar principle of creating more than one sealing line implemented in the belts233wherein two lips332are provided to create two sealing lines with the surface236.

To remove dust and small obstacles ahead the front roller232, a vacuum cleaning unit340shown inFIG.14is coupled to the shielding207. A vacuum suction duct342cleans the lane ahead of the roller232and tracks230, to assure smooth operation and minimize the number of obstacles on the surface236. As shown inFIG.15A, the vacuum air-flow is in an open-loop: an air blower248driven by an electric motor250applies suction through a suction duct342ahead of the front roller232for capturing contaminated air, which is discharged into the disinfection chamber300by a pipe246. To achieve faster actuation response of adjustable lips304, a controller responsive to sensor signals can control a discharge valve346actuated by a servo motor (not shown). The discharge valve346lets the air move into the space between the shield207and the chamber300and thereby controls the amount of air flowing via the adjustable lips304. This closed-loop control is faster and much more precise than control based on power/speed regulation of the air blower motor250described above.

FIG.15Bshows pictorially in cross-section the main features of the vacuum unit340. After being sucked through the duct342, the air flows via a bag filter (not shown) located inside a filter compartment350and then directed by the air blower248into the pipe246.

FIG.16shows an arrangement of the UV light sensors308and visible spectrum light sensors280are located in between the shielding207and the disinfection chamber300, or more precisely, between the floating track-barrier mechanism310and the auxiliary chamber300. Visible spectrum light sources (LED)282are coupled to the shielding207margins and to the vacuum unit340.

The description of the above embodiments is not intended to be limiting, the scope of protection being provided only by the appended claims.

It is to be noted that the terms “upper” and “lower” as used in the foregoing description when applied to the ends of the disinfection chamber define their orientation relative to the surface being disinfected. Thus, when the device is used to disinfect a horizontal surface, such as a floor, these terms also correspond to their actual orientation in space. However, when the device is configured for riding on a surface that is not horizontal, such as a vertical wall, the “lower” open end of the disinfection chamber will now be vertical and adjacent to the wall surface, while the “upper” end will be remote from the wall surface. Therefore, in the claims, the “lower” and “upper” ends are referred to as “proximal” and “distal” respectively, which are equally applicable regardless of whether the device is horizontal or inclined to the horizontal during actual use.

Although the device has been described with particular regard to a UV radiation source, it will be appreciated that the principles of the invention are equally applicable to other potentially hazardous radiation sources.

Features described with reference to one or more embodiments are described by way of example rather than by way of limitation to those embodiments. Thus, unless stated otherwise or unless particular combinations are clearly inadmissible, optional features that are described with reference to only some embodiments are assumed to be likewise applicable to all other embodiments also.