DESCRIPTION

The object of present are means adapted to limit the bacterial and virological proliferation in water for hygienic-domestic and/or food use.

More precisely, the object of the present invention is an immersion device adapted to sanitise the water contained in a storage tank or the like.

Even more precisely, the object of the present invention are immersion devices capable of implementing the dual function of control and management of the temperatures of the water (or similar fluids) inside a storage (or the like) and the sanitisation of the same.

The invention mainly falls within the sector of the production of household appliances, more precisely in the field of the realisation of the laundry washing machines, washer-dryers and/or dishwashers that may be used both within the domestic and industrial scope.

Of course, nothing prevents the possibility of extending the use of the aforementioned immersion device also to other sectors, for example, in that of the electric storage water heaters, tanks for storing water for food and domestic use or in all those water storages, temporary or not, where there is the risk of proliferation of bacteria, germs and/or viruses.

It is known that all the aforementioned household appliances, while differing from each other by constructive and functional features, are associated with the presence of at least one storage and at least one electric resistance (or similar components) that, by cooperating with suitable temperature probes, heat and bring said water at a temperature compatible with the service that they must deliver, for example, in order to meet a hot water drawing for domestic or food uses or for the washing of laundry or dishes.

The risk of proliferation of bacteria, viruses and/or germs in water storages is also known.

For example, in storage water heaters the maintenance of water at much lower temperatures than in the past for energy saving needs as well as cold washing programs implemented in laundry washing machines or dishwashers have contributed to amplify the proliferation of bacteria and/or pathogens.

Similarly, despite the cleansing and sterilising function of the detergents used, in the tubs of laundry washing machines and dishwashers, the dirt that inevitably deposits there as a result of the washing processes may be a breeding ground for germs harmful to health, not to mention that they may already be present in the water with which the machine is fed.

In order to limit such drawback, ultraviolet rays generators have been progressively integrated into said household appliances able, as known, to reduce or break down the virological and/or bacterial load possibly present in the water.

For example, in the sector of laundry washing machines or dishwashers, ultraviolet emitters, suitably mounted in the washing water supply pipes and/or inside the drum and/or in the inner walls of the relative washing tanks, have long been provided for and used.

However, such technical choices have not proved to be free from drawbacks.

Frequently, due to construction limits and constraints, such ultraviolet emitters are positioned in points wherein the contact with the washing water is not always guaranteed; this may lead to a reduction in their sanitising effect.

Many of the components mentioned above as possible seat for the assembly of the ultraviolet emitters are made of plastic material, with a view to a containment of the production costs and simplification of the production processes. Therefore, there is the risk that such ultraviolet emitters, if not suitably positioned and immersed in water, directly irradiate said plastic components, accelerating their ageing process; this may lead to frequent maintenance interventions or replacement of the worn components, with negative consequences on the functionality of the appliance and on the related management costs.

Equipping said household appliances with ultraviolet emitters has further required their substantial redesign or, in any case, adaptations and structural modifications so as to make their installation possible.

Furthermore, implementing a sanitisation function of the water used in a household appliance means providing and adding a new specific component, therefore exposing said household appliance to a greater risk of malfunctions or disservices, and consequently to an increase of the maintenance and repair costs. The object of the present invention is to eliminate the drawbacks of the prior art, listed above, by integrating a device for the sanitisation of the water stored and/or used in a household appliance, such as for example a laundry washing machine, a dishwasher or a storage water heater or similar equipment, in a component already provided and supplied with said household appliance.

More precisely, the object of the present invention is to integrate a device for the sanitisation of the water stored and/or used in a household appliance, such as for example a laundry washing machine, a dishwasher or a storage water heater or similar equipment, in a component normally provided and in charge for controlling the heating and/or thermostating of said water.

A further object of the present invention is to provide for an immersion device for the sanitisation and/or thermostating of the water stored and/or used in a household appliance, such as for example a laundry washing machine, a dishwasher or a storage water heater or similar equipment, which is efficient, economical and reliable and without this entailing substantial modifications to the structure and/or basic components of said household appliance.

A further object of the present invention is to provide an immersion device for the sanitisation and/or thermostating of the water that allows retrofiting and/or upgrading operations of household appliances already produced and in operation.

These and other objects are achieved in accordance with the invention, with the features listed in the annexed independent claim 1.

Further features of the present invention shall be better highlighted by the following description of one or more preferred embodiments, in accordance with the patent claims and illustrated, purely by way of a non-limiting example, in the annexed drawing tables, wherein:

- Fig. 1 schematically shows a section and a detail of a laundry washing machine according to a possible executive embodiment of the invention;

- Fig. 2 schematically shows an axonometric view of the device for the sanitisation and/or thermostating of the water temperature according to a first variant of the invention;

- Figs. 3a and 3b show, in a perspective and section view, an exemplary schematisation of the device for the sanitisation and/or thermostating of the water of Fig. 2;

- Fig. 4 schematically shows an axonometric view of the device for the sanitisation and/or thermostating of the water temperature in accordance with a second variant of the invention

The elements of the immersion device of the invention for the sanitisation and/or thermostating of the water are now described using the references contained in the attached figures. Not necessarily, what described in the figures is to scale, with the purpose of highlighting some features instead of others.

It is also noted that any dimensional and spatial term (such as “lower”, “upper”, “inner”, “outer”, and the like) refers to the positions of the elements as shown in the attached figures, without any limiting intent relative to the possible operating conditions.

In the present description, at least initially, reference shall be made to a sanitisation function of the water contained within a generic storage provided in a household appliance and used for different purposes, e.g., such as washing water, rinsing water, domestic water or the like.

Hereinafter, “storage” is generically to be understood as any tank, vessel or container, in the most varied shapes, geometries and volumes, able to store a certain amount of water.

For descriptive simplicity, regardless of the type of household appliance and function thereof, said water shall be indicated with the expression “service water”, while the device in charge of said sanitisation function and elimination of bacteria, viruses, germs or other pathogens shall be referred to as “sanitising device”.

According to a possible variant of the invention, said sanitising device may be integrated in household appliances that provide for heating of the water contained in the storage thereof, such as, without any limiting intent, laundry washing machines, washer dryers, dishwashers and/or in a storage water heater, heat pumps, solar storages or, more generally, in any other tank or water vessel subject to phenomena of bacterial proliferation and/or diffusion of viruses and pathogens.

In such case, said sanitising device is preferably installed in the proximity of one of the means of the household appliance normally intended for heating the service water and being advantageously integrated on a component already equipped with said household appliance.

Without any limiting intent, the sanitising device of the invention may therefore be positioned on an inner wall of the storage, in the proximity of at least one electric resistance thereof and integrated into the device normally setup for the control and the thermostating of the service water.

In fact, it is known that an electric resistance, electrically insulated relative to the walls or body of the storage, is generally “immersed” in the service water in order to correctly carry out the specific heating function thereof.

Therefore, the substantial proximity of the sanitising device of the invention to said electric resistance: - ensures direct and effective purification of the service water,

- involves, at least for some specific applications, important advantages in terms of operation and durability of the household appliance that implements it (e.g., with particular reference to the parts thereof and/or components of plastic material).

Experimentally, it has been further observed that the sanitisation device of the invention, when positioned at the aforementioned electric resistance, may maximize and improve the sanitising effect thereof.

In fact, it would be advantageously located in a zone of the storage characterised by a consistent exchange of water, ensured by the convective motions due to the heating thereof; this may favour a reduction in the proliferation of bacteria, viruses, germs or other pathogens harmful to health and/or a more efficient reduction thereof.

Scientific studies and laboratory tests have also proved that the ultraviolet radiation, in addition to having a sanitising effect, may contribute to slow down and/or limit the formation of limescale on the surfaces in contact with the service water, especially if rich in calcium carbonates.

In particular, it has been proved that the exposure to the ultraviolet light of said water mainly produces calcite crystals which, being less dense and adherent than other types of calcium carbonate compounds are more easily removable from the surfaces whereon they deposit, for example from the inner walls of a storage of a household appliance or from the functional components thereof.

I.e., there would be a strong mitigation of the calcareous encrustations on said surfaces and/or components and, as a consequence, of the technical problems that may arise in terms of heat transfer, anomalous energy consumptions and frequency of maintenance interventions.

In the aforementioned household appliances, it is also known the use of at least one temperature probe able to:

- detect the temperature of the service water contained in the storage thereof, and consequently - “drive”, by activating or deactivating them, the relative one or more electric resistances, so as to allow an appropriate thermostating of said service water up to a temperature sufficient to meet the service that the household appliance must deliver (e.g., a drawing for sanitary or food use and/or suitable for the washing of laundry or dishes).

The already available and generally known temperature probes differ from each other based on the position and installation method thereof, the type of technology that manages them and/or, more simply, based on their geometrical shape. With reference to the latter case, both probes having a substantially cylindrical, tapered and “elongated” geometry and of the “button” type are for example known, which have a more “flattened”, “low” and “flat” shape compared to the first ones.

A “button”-type temperature probe 1 is for example shown in Fig. 2 and/or 3 and/or 4.

The outer casing or container body 10 of said probe 1 is shown in particular, that houses at least the main functional components, such as at least the temperature sensor 2 and at least part of the relative printed circuit 3 (or PCB) whereon it is mounted.

Without any limiting intent, said temperature sensor 2 may preferably comprise at least one NTC or PTC thermo-resistor, or similar components adapted to detect at least the temperature of the service water wherein the probe 1 is immersed and/or in direct contact.

One or more holes 11 (or slots or similar openings) obtained passing on said container body 10, for example at the base 100 thereof, allow the temperature probe 1 to be fixed, by means of screws or similar means, to a wall 500 of the storage 50 of a household appliance 5, and the consequent correct installation thereof in the seat 56 dedicated thereto (from now on see Fig. 1, that shall be referred to extensively during the description).

Thus installed, said temperature probe 1, as partly already anticipated, protrudes inwards of the storage 50, resulting substantially in contact with or immersed in the service water contained therein, at least when in operating conditions (e.g., during one or more operating steps of the household appliance 5).

According to the invention, said temperature probe 1 further comprises at least one device 4 for the sanitisation of said service water of the storage 50 from bacteria, viruses and/or other pathogenic microorganisms.

Said sanitising device 4, which is preferably housed inside the container body 10, may consist of an ultraviolet emitter 40 comprising one or more UV (ultraviolet) lamps or UV LEDs 41 that are also preferably mounted on the same printed circuit board (or PCB) 3 of the temperature sensor 2.

According to the invention, said container body 10 may further comprise:

- at least one part 101 transparent to the ultraviolet radiation generated by said at least one lamp UV LED 41 of the sanitising device 4, said part 101 (hereinafter also referred to as “capsule 101”) being preferably that intended to be immersed or in direct contact with the service water,

- one section (not explicitly shown in Fig. 2 and/or 3 and/or 4) for the passage of at least the cables or electric power connectors of said printed circuit board (or PCB) 3 and/or of the relative components installed thereon (for example, said one or more lamps or UV LED 41, thermal resistors, etc.).

Preferably, said capsule 101 of the temperature probe 1 of the invention is suitably shaped and sized to contain therein at least said temperature sensor 2 and sanitising device 4 which, for reasons that shall be clarified shortly and without any limiting intent, are positioned in substantial proximity and/or adjacent to each other, without prejudice to their inevitable overall dimensions and the consequent installation constraints.

For such purpose, said capsule 101 may for example have a hemispherical geometry (shaped as a cap or dome), as shown in Fig. 2, although nothing prevents the possibility of providing other equally functional shapes for the purposes, for example, cubic, pyramidal, cylindrical (as shown in Fig. 4), conical/truncated-conical or the like.

It is further specified and reiterated that the sanitising device 4 may be electrically powered and/or cooperate with the same power supply means already provided for the temperature probe 1.

Similarly, the switching on and operation thereof may be delegated to specific electromechanical selectors (the classic knobs or keys of a user interface) and/or automatically to the electronic control unit with which each household appliance is normally equipped.

Furthermore, the operation of the sanitising device 4 may be correlated to the presence of water inside the storage 50 of the household appliance 5 and, in at least one executive embodiment thereof, to its temperature, suitably detected and acquired by the temperature sensor 2 of the probe 1 whereon it is, as seen, integrated.

In fact, according to the invention, said at least one temperature sensor 2 may detect and/or control at least:

- the service water temperature inside the storage 50 of a household appliance 5 so as to activate the ultraviolet emitter 40 of the “sanitising device” when it is lower than a threshold value (e.g., equal to 60 °C) below which there is a non- negligible risk of development and proliferation of bacteria, viruses or pathogens (for water temperatures higher than said threshold, the sanitisation occurs spontaneously without any need of intervention of the sanitising device 4), whereas, when the sanitisation device 4 is already active,

- the temperatures reached by the ultraviolet emitter 40 so as to identify any anomalous overheating of the relative one or more lamps or UV LED 41 indicative of potential failures and malfunctions (e.g., from a short circuit), such control function being facilitated by the substantially adjacent and/or close positioning of said temperature sensor 2 and sanitising device 4.

In other words, the temperature probe 1 of the invention is able to provide a measurement of a temperature that may represent:

- reliably, the temperature of the service water with which it is in direct contact and on the basis of which the sanitising device 4 may be activated or not, and/or

- with sufficient and tolerable approximation, the temperature around the ultraviolet emitter 40 so as to deactivate it in case of dangerously high values and to preserve the efficiency and operating duration thereof,

The identification of any failures of the ultraviolet emitter 40 may in any case require the implementation in the electronics of the household appliance 5 of suitable logics and safety algorithms.

For example, a possible algorithm may provide for alternating programmed switching on and off of the sanitising device 4 and for measuring, from time to time, the temperature of the service water around the temperature probe 1 so as to distinguish the possible contribution of the sanitising device 4 from that of the electric resistance 51 normally used, as known, for the heating of the service water.

In fact, if the temperatures detected with the sanitising device 4 switched on are substantially equal to those with the sanitising device 4 switched off, no failure of the same is detected; otherwise, if said temperatures differ by a predefined threshold, this may be a sign of anomalous overheating of the ultraviolet emitter 40 which may be deactivated as a precaution.

Alternatively, nothing prevents the possibility of providing for an additional temperature sensor directly associated with the ultraviolet emitter 40 and dedicated exclusively to the detection of the temperatures reached by one or more lamps or UV LED 41 (variant not shown in the figures attached to this description). In this case, there would be a direct and precise measurement of the temperature around the sanitising device 4 that enables the safe and timely identification of possible overheating caused by failure or malfunctions without the need for approximations and/or specific control algorithms.

It should also be noted that, when the activation of the sanitising device 4 of the invention is not required or necessary (e.g., as mentioned, for service water temperatures that are already sufficient to avoid any risk of pathogenic proliferation), the temperature probe 1 of the invention, by means of the relative temperature sensor 2, may normally be used to “drive” the service water heating components 2 according to the temperature actually detected.

In other words, the temperature sensor 2 of the temperature probe 1 of the invention integrating a sanitising device 4 may also be used only for the thermostating of the service water, i.e. for the activation and deactivation of an electric resistance 51 of the storage 50 of a household appliance 5 (exactly as with the traditional and known probes of the state of the art used up to now).

According to the invention, there is therefore the possibility of combining in a single immersion component both the service water sanitisation and managing function of the heating and thermostating thereof, consequently reducing the number of components and accessories of a household appliance with advantages in terms of production, marketing and maintenance costs.

In order to maximize and improve the sanitising function of the temperature probe 1 of the invention, at least the capsule 101 of the container body 10 thereof is preferably made of quartz glass.

In fact, as already mentioned, said material:

- is particularly transparent and/or permeable to the ultraviolet radiation, effectively allowing the radiation of the ultraviolet emitter 40 of the sanitising device 4 to pass through,

- has physical characteristics suitable for and compatible with the use and the operation of the aforementioned one or more temperature sensors 2 for the control of the anomalous overheating of the same ultraviolet emitter 40 and/or for the detection of the temperatures of the service water contained in a storage 50 of a household appliance 5.

In fact, it is known that quartz glass is characterised by a high thermal conductivity and at the same time by a high electric resistivity.

In practice, a quartz capsule 101 (or, more generally, the entire container body 10) is able to electrically insulate both the ultraviolet emitter 40 and said one or more temperature sensors 2 of the temperature probe 1 of the invention from the support whereon it is mounted, for example from the walls 500 (when metallic) of the storage 50 of a household appliance 5.

Compared to the steel or plastic capsules currently used, the quartz glass also ensures greater precision and reactivity in reading the service water temperatures of the tank 50.

In fact, it is known that steel, characterised by high electrical conductivity, would require the aforementioned one or more temperature sensors 2 of the probe 1 of the invention to be electrically insulated, e.g. by means of the use of specific resins, by significantly lowering the thermal conductivity thereof.

On the other hand, caps 101 made of plastic material, while not requiring the need for insulating resins, would not guarantee adequate levels of thermal conductivity and may be subject to a rapid degradation of their physicalfunctional features due to the effect of the same ultraviolet radiation.

The use of quartz glass may also allow an improvement of the time constant, i.e. of the response time (indicative of the reactivity of the system) of the aforesaid one or more temperature sensors 2, consequently allowing possible monitoring of the temperature trend of the service water or of the humidity degree in case of emptying of the storage 50.

It has been said several times that the temperature probe 1 of the invention integrating a sanitising device 4, for the correct operation thereof, may be installed directly on an inner wall 500 of the storage 50 of a household appliance 5, provided that it is in the proximity of the relative electric resistance 51 for the heating of the service water and in contact with said water.

However, through small adaptations within the reach of a person skilled in the art, nothing prevents the possibility of providing for different applications, for example, on the flange 52 of said electric resistance 51, on the face whereof that supports the heating element 510 (e.g. coil-shaped or tubular) a suitable installation seat may therefore be provided and obtained (also this variant, however, not shown).

Having dealt with the invention in the more general aspects thereof, a specific application thereof, that is among the preferred ones is now described, i.e. without any limiting intent, on a laundry washing machine 5 (such term also means similar household appliances such as the so-called “washer-dryers”).

As shown in Fig. 1, like the solutions of the state of the art, the temperature probe 1 of the invention, comprising a sanitising device 4 shall be positioned on the tub 50 of the laundry washing machine 5.

Said tank 50 defines the aforementioned storage and a drum 53 rotates therein wherein the clothes and the laundry to be washed are loaded through a relative porthole 54.

By way of an example, said temperature probe 1 may be installed at a first housing or seat 56 obtained on a wall 500 of the tank 50, e.g. on the bottom 500 thereof set up with the hydraulic group 57 for draining the water at the end of each washing step and/or process, and, for the reasons explained above, preferably in the proximity of the electric resistance 51 for the heating of the service water (in this case washing water).

Without any limiting intent and always with reference to Fig. 1, said electric resistance 51 may be positioned for such purpose on the rear wall 501 of the tank 50, substantially in the proximity of the connection zone thereof with the bottom 500.

Such positioning of the temperature probe 1 is the one that ensures the constant contact with the washing water, at least during the washing and rinsing steps, when in fact it is completely immersed therein.

This allows direct and targeted ultraviolet irradiation of the washing water and, consequently, of the clothes and laundry which will therefore be adequately sanitised.

At the same time, it is avoided that the inner walls of the tank 50 (or other functional components), increasingly made of plastic material, are affected and directly exposed to said ultraviolet radiation, actually slowing down the consequent ageing or degradation process thereof.

The ultraviolet radiation also reduces, as seen, the calcareous deposits on the electric resistance 51 or on other components inside the tub 50 of the laundry washing machine 5.

This translates into a reduction in the number of maintenance interventions or replacement of malfunctioning or worn components, ensuring full functionality of the household appliance, low management costs and an extension of their operational life.

With reference to the field of laundry washing machines 5 (or similar washing machines), the temperature probe 1 of the invention comprising the sanitising device 4, managed by the machine control electronics:

- shall be able to carry out its washing water sanitisation function (with relative possible monitoring of anomalous overheating of the ultraviolet emitter 40 thereof) during, for example, the typical rinsing steps (generally carried out at low temperature), whereas

- it shall act as a “traditional” temperature probe during the water heating and thermostating steps for the high temperature washing steps, for example for the activation/deactivation of said at least one electric resistance 51.

It should be noted that only the functional main components of the laundry washing machine 5 have been described for the purposes of the invention. All the other elements thereof not directly related to the object of the invention, but well known to a person skilled in the art (for example the motor and the relative transmission members for the rotation of the drum 53 such as pulleys 58 and belts 59, ballasts and shock absorbers inside the body, the gaskets, the user interface and the electronic control unit, etc.), have been therefore voluntarily omitted.

It is also clear that in the practical embodiment of the invention numerous modifications and further variants may be provided, all falling within the same inventive concept

For example, all of the above with reference to the aforementioned washing machine 1 may be extended, with minimal adaptations within the reach of a person skilled in the art, to any other type of household appliance comprising an inner storage for the service or washing water, in particular to the dishwashers, both domestic and industrial, to heat pumps or storage water heaters.

Furthermore, given its functional, geometrical and dimensional features, nothing prevents the temperature probe 1 of the invention from being applied also in other components of said household appliances 5, for example in the inner pipes thereof for the supply of the service water, in the body of the circulation pump or in any other part of the equipment wherein a contact, at least temporary, with said service water is substantially guaranteed (although in these cases the effectiveness of the sanitising effect due to the heating of the same water to works of the aforementioned one or more electric resistors) may be reduced.

Finally, it should be noted that the desired purposes are achieved with the temperature probe 1 of the invention incorporating a service water sanitisation device 4.

In particular, there is the possibility to implement a service water sanitisation function in a component already provided and equipped with a household appliance (such as, for example, a laundry washing machine, a dishwasher or a storage water heater or similar equipment) by reducing the number of components with advantages in terms of costs and reliability.

Furthermore, such integration does not involve substantial changes to the structure and/or basic components of these household appliances and enables and facilitates retrofitting and upgrading operations on household appliances already on the market and/or used, allowing the simple replacement of the traditional temperature probes with those of the invention.