Background of the invention

[0001] The present invention relates to an electronic thermostatic mixing device for dispensing hot, cold and mixed water and a method for thermally disinfecting an electronic thermostatic mixing device.

[0002] Specifically, but not exclusively, the device and/or the method according to the invention can be applied in the field of sanitary installations, in particular in the public domain, for example in the washbasins of public restrooms or in public showers.

Particularly, the device and/or the method that is the object of the invention can be used in a hospital environment, i.e., in washrooms of health facilities.

[0003] The device and/or the method can also be applied in a domestic environment, in a washbasin or shower in a private dwelling.

Prior art

[0004] A mixing device is known for dispensing hot, cold and mixed water provided with an anti-scalding device. The prior art mixing device features a sensor of contactless type that is suitable for detecting the presence of a hand of the user and dispensing water for a preset period of time to enable parts of the body of the user to be washed such as for example the hands, in normal operation.

[0005] In addition to normal operation, the mixing device is subjected to a thermal disinfection operation to eliminate viruses or bacteria present in the water. The thermal disinfection operation involves circulating water at a relatively high temperature (for example greater than 70 °C) to eliminate viruses and/or bacteria (like, for example, Legionella) inside conduits inside the mixing device for a set duration (for example of the order of minutes) that is necessary for performing the disinfection operation, so as to enable the hot water to perform the disinfecting action.

[0006] One drawback of the prior art is that the mixing device has relatively large dimensions. The large dimensions of the prior art mixing device cause poor assembly flexibility of the mixing device in a washbasin (or in a shower). This is especially true in the public field, for example in the hand-washing stations in public washrooms, where the space is optimized to install a large number of mixing devices to ensure several free stations to a user.

[0007] Another drawback of the prior art is that it is complicated to perform the thermal disinfection operation. In fact, during the thermal disinfection operation, in order to increase the length of time of dispensing of the hot water, a mixing device maintenance operative is forced to operate the sensor continuously (or several times) in order to enable the hot water to perform the bactericide function. In fact, commercially available sensors are configured with a “ safety time out” function, i.e. a period of safety of the order of a few (about 2-3) minutes on the basis of which if the beam of the sensor is obscured (or blocked), for example by dirt or soap and water to be dispensed, water dispensing is permitted only until the end of the safety period in order to then stop. Once the “safety time out” setting is activated, the sensor no longer permits dispensing of water until the sensor detects that the cause of the obscuring has been removed. As a result, the thermal maintenance operation is inconvenient for the maintenance operator and this results in malfunctions and an increase in the periods of non-use of the washing station/s. In fact, a thermal disinfection operation involves a duration of dozens of minutes (also on the basis of the disinfection water temperature), i .e. a duration that is greater than the safety period.

[0008] A further drawback of the prior art is the impossibility of adjusting a correct water flowrate during the thermal disinfection operation. More precisely, it is difficult to set a minimum flowrate that is sufficient to ensure effective and complete sanitization; thus very often excessive waste of water occurs during the thermal disinfection operation. This waste of water is accentuated particularly in the applications of the mixing device in public washrooms (or showers) where owing to a high number of installations, an enormous flowrate of hot water - resulting from the sum of the individual flowrates of each mixing device - is dispersed overall into the discharges.

[0009] In the light of what has been set out above, it would therefore be desirable to dispose of an electronic thermostatic mixing device and of a method for thermally disinfecting an electronic thermostatic mixing device that is able to overcome all the limits listed above.

Objects of the invention

[0010] One object of the invention is to overcome the limits and drawbacks of the prior art listed above.

[0011] Another object is to provide a compact technical solution that is such as to be able to be fitted to any type of washbasin, in particular in confined spaces. [0012] A further object is to provide a solution that enables the time of dispensing water during the thermal disinfection operation to be increased.

[0013] A still further object is to provide a solution that decreases water waste during the thermal disinfection operation.

[0014] Another object is to provide a technical solution that facilitates the task of the user and makes the thermal disinfection operation more rapid and convenient.

Short description of the invention

[0015] Such objects, and still others, are achieved owing to an electronic thermostatic mixing device and by a method for thermally disinfecting, according to what has been defined in the appended claims.

[0016] Owing to the solution according to the present invention it is possible to provide a compact electronic thermostatic mixing device.

[0017] Owing to the device and to the method according to the invention, it is possible to extend the dispensing time that is necessary to perform the complete anti-Legionella thermal disinfection cycle.

[0018] The electronic thermostatic mixing device and the method according to the invention enable the waste of water during the thermal disinfection operation to be decreased.

[0019] Owing to the solution according to the invention, an electronic thermostatic mixing device is provided that is cheap and simple from the constructional and functional point of view.

Short description of the drawing

[0020] The invention can be better understood and implemented with reference to the drawings that illustrate embodiments thereof by way of non-limiting example, in which:

Figure 1 is a perspective view of a first embodiment of an electronic thermostatic mixing device according to the present invention provided with temperature adjusting means that are actuatable directly by a user;

Figure 2 is a perspective view of a first embodiment of an electronic thermostatic mixing device of Figure 1 in which a cover element of the temperature adjusting means are removed to provide access to a housing cavity;

Figure 3 is a perspective view of the electronic thermostatic mixing device of Figure 1 in which a disinfection activation tool is inserted into the housing cavity of Figure Figure 4 is a schematic view of a second embodiment of the electronic thermostatic mixing device and of a disinfection unit for performing a thermal disinfection operation;

Figure 5 is a raised lateral view of the electronic thermostatic mixing device of Figure 4;

Figure 6 is a raised frontal view of the electronic thermostatic mixing device of Figure 5;

Figure 7 is a lateral view of the electronic thermostatic mixing device of Figure 1 in which a median plane is shown;

Figure 8 is a section of the electronic thermostatic mixing device of Figure 1 taken through the median plane shown in Figure 7 that shows the disinfection activation tool coupled with a thermostatic cartridge, and flowrate adjusting means in a flowrate choking position;

Figure 8a is a schematic perspective view that shows the electronic thermostatic mixing device of Figure 1 in which a cover has been removed to provide an adjusting tool with access to the flowrate adjusting means;

Figure 9 is a section like that of Figure 8 that shows a thermostatic cartridge in an expanded disinfection configuration and the flowrate adjusting means in an open position,

Figure 10 is a section like that of Figure 8 that shows the flowrate adjusting means in a closed position;

Figure 11 is a raised frontal view of the electronic thermostatic mixing device according to one version of the first embodiment;

Figure 12 is a raised lateral view of the electronic thermostatic mixing device of Figure 11;

Figure 13 is a perspective view of the electronic thermostatic mixing device of Figure 11;

Figure 14 is a perspective view of the electronic thermostatic mixing device of Figure 11;

Figure 15 is a raised frontal view of the electronic thermostatic mixing device according to a version of the second embodiment;

Figure 16 is a raised lateral view of the electronic thermostatic mixing device of Figure 15; Figure 17 is a perspective view of the electronic thermostatic mixing device of Figure 15;

Figure 18 is a perspective view of the mixing device of Figure 15;

Figure 19 is a perspective view of the mixing device of Figure 4 with a cover element removed;

Figure 20 is a perspective view of the device of Figure 19 with an adjusting key inserted to dismantle a safety element;

Figure 21 is a perspective view of the device of Figure 19 with the adjusting key inserted to actuate the temperature adjusting means.

Detailed description

[0021] The general features of the present invention will be illustrated below through some embodiments.

[0022] With reference to the aforesaid figures, with 1, 1’ an electronic thermostatic mixing device for dispensing hot, cold and mixed water according to the present invention has been indicated. The electronic thermostatic mixing device 1, 1’ can be applied in the field of sanitary installations, in particular in the public domain, for example in the washbasins of public washrooms, in particular in washrooms of hospitals (or in public showers). The electronic thermostatic mixing device can also be applied in a domestic setting, in a domestic washbasin or shower.

[0023] The electronic thermostatic mixing device 1, 1’ comprises a hollow case 2 having an inlet for the hot water 2a and an inlet for the cold water 2b. The case 2 mainly extends along its own longitudinal axis L and has a cylindrical form (Figures 5 and 9). In particular, the case 2 can have a tilted cylinder shape, where the tilt is defined by an angle, in particular an acute angle, between the longitudinal axis L of the cylinder (Figure 9) and a reference plane (not shown) on which the electronic thermostatic mixing device 1, 1’ can be fitted. The reference plane can be obtained on an edge of a washbasin (or on an equipped wall of a shower).

[0024] The electronic thermostatic mixing device 1, 1’ comprises a mouth portion 3 for dispensing the water. This mouth portion 3 faces outwards from a side of the case 2. The mouth portion 3 can be arranged in particular near a top portion of the case 2. As mentioned, an outlet for the water is arranged at the mouth portion 3.

[0025] The electronic thermostatic mixing device 1, 1’ comprises a thermostatic cartridge 4 configured to control the incoming hot and cold water flows so as to enable mixed water to be dispensed at a required mixing temperature through the mouth portion 3. [0026] The electronic thermostatic mixing device 1, 1’ comprises an automatic activation device 5, mounted on the case 2, and configured to enable, upon a command from a user or an operator water to be dispensed for a preset period of time. The automatic activation device 5 thus enables the user to perform a washing operation (for example to wash hands). In the context of the invention, this washing operation is referred to as “normal operation” of the electronic thermostatic mixing device.

[0027] The electronic thermostatic mixing device 1, 1’ comprises a thermal disinfection unit 6 for performing a thermal disinfection operation. The thermal disinfection unit 6 is configured to enable only hot water to circulate inside the case 2 and lastly flow out to the outside through the mouth portion 3. The thermal disinfection operation can comprise a bactericide thermal disinfection cycle, like for example an antiLegionella thermal disinfection cycle. In fact, the electronic thermostatic mixing device 1, 1’ can be subjected to this thermal disinfection operation to eliminate viruses or bacteria present in the water. The thermal disinfection operation requires water to be circulated at a relatively high temperature (for example equal to or greater than 70 °C) to eliminate viruses and bacteria (like Legionella) inside the case 2 and through the mouth portion 3 for a set duration (for example of the order of minutes), so as to enable the hot water to perform a disinfecting action

[0028] Inside, the case 2 has one or more cavities, which define housings for inner components of the mixing device and transit conduits for the water, as will be explained better below in this description. A housing cavity 2e which is configured to house the thermostatic cartridge 4 is obtained in the case 2.

[0029] The housing cavity 2e extends mainly transversely, in particular perpendicularly, to the longitudinal axis L of the case 2. In the illustrated embodiments, the housing cavity 2e is a cavity with a bottom with respect to the case 2. Nevertheless, in one embodiment that is not illustrated, the housing cavity can be a through cavity with respect to the case 2 and can be closed appropriately by closing elements.

[0030] In the illustrated embodiments, the housing cavity 2e (and thus the thermostatic cartridge 4) is positioned near a base portion of the case 2, which is opposite the top portion in which the mouth portion 3 is arranged.

[0031] The automatic activation device 5 comprises, in particular, a presence sensor 5a that is suitable for detecting the presence and/or the movement of a part of the body like a hand of the user in proximity to the mouth portion 3. The automatic activation device 5 is configured, in particular, to automatically start dispensing water (by activating an electrovalve 5b) on the basis of a signal issued by the presence sensor 5a. In the illustrated embodiment, the presence sensor 5a is arranged near the mouth portion 3. The presence sensor 5a can be connected operationally to the control unit 14.

[0032] In one embodiment that is not illustrated, additionally or alternatively to the presence sensor 5a, the automatic activation device 5 can comprise a touch key (which is not shown) which is arranged to detect the contact of the user.

[0033] The disinfection unit 6 comprises a disinfection actuation device 14a configured to start an anti-Legionella thermal disinfection cycle by the operator. The disinfection actuation device 14a is operationally connected to and controls an electrovalve 5b such that the electrovalve 5b remains in an open condition. In the illustrated embodiment, the disinfection actuation device 14a is connected operationally (directly) to the electrovalve 5b. In other words, the disinfection actuation device 14a is operationally connected to and controls an electrovalve 5b to enable water dispensing so as to impose a water dispensing duration that is necessary for performing a complete an anti-Legionella thermal disinfection cycle. This water-dispensing duration is independent of the set period of time associated with the automatic activation device 5.

[0034] In the illustrated embodiment, the disinfection actuation device 14a is positioned at, in particular on the top of, the electrovalve 5b. In this embodiment, the disinfection actuation device 14a can be covered by the removable cover 7c, in particular during normal operation.

[0035] Additionally, or alternatively, the disinfection actuation device 14a can be operationally linked to the control unit 14 to activate an override function of the sensor 5a and thus enable the water to be dispensed during the thermal disinfection operation. In the embodiment in which the control unit 14 is present, the disinfection actuation device 14a can be arranged at the control unit 14. The control unit 14 can be integrated into the electronic thermostatic mixing device 1, 1’, in particular can be housed inside the case 2. In the illustrated embodiment in Figure 4 the control unit can be detached from and positioned outside the case 2. In this embodiment the control unit 14 can be positioned in a hidden place, for example behind the sink or washbasin on which the mixing device is installed.

[0036] In the illustrated embodiment, the disinfection actuation device 14a comprises an actuating device of tactile type, such as an actuating key or button suitable for receiving a tactile action from the operator. This actuation key can be actuatable (directly) by pressure from the operator, or alternatively by touching by the operator.

[0037] In a further embodiment that is not illustrated, the disinfection actuation device can comprise a magnetically actuated internal start unit, housed in the case and a detached external activation unit suitable for being handled by the operator to be taken near the magnetically actuated internal start unit to interact magnetically with, and activate, the magnetically actuated internal start unit. In other words, this magnetically actuated internal start unit is actuatable from outside (i.e., without removing the removable cover 7c) by a specific tool. In this embodiment that is not illustrated, the external actuating unit can comprise a portion of magnetic or ferromagnetic material (or an electromagnet).

[0038] The disinfection actuation device 14a can be actuated at the start of the disinfection cycle, so as to maintain the electrovalve 5b open and thus permit a transit of hot disinfecting water, and then be actuated further (again) at the end of the disinfection cycle, so as to restore normal operation in which the sensor 5a commands the electrovalve 5b.

[0039] The disinfection unit 6 can comprise, in particular, a control unit 14 that is operationally connected to and controls the electrovalve 5b to enable the water to be dispensed by disabling the automatic activation device 5 The control unit 14 is configured and programmed to perform, at the start of the anti-Legionella thermal disinfection cycle, an override function that imposes a water dispensing duration that is necessary for performing a complete anti-Legionella thermal disinfection cycle and that is independent of, and in particular greater than, the preset period of time associated with the automatic activation device 5. In other words, the override function can override, and thus obtain greater priority over the normal operation of the mixing device 1, 1’ such that the electrovalve 5b is activated for a hot water dispensing duration that is greater than the preset time associated with normal operation.

[0040] The disinfection unit 6 comprises, in particular, flowrate adjusting means 7 configured to vary the hot water flowrate circulating during the anti-Legionella thermal disinfection cycle.

[0041] The flowrate adjusting means 7 can comprise a choke valve 7a arranged for varying a water transit area and thus varying the water flowrate (that has gone through the thermostatic cartridge 4). In other words, the flowrate adjusting means 7 are configured to cause constriction in a transit conduit 12 (at a narrowing section 11) to vary the flowrate of water to be dispensed. The transit conduit 12 is downstream of the thermostatic cartridge 4 upstream of the dispensing mouth 3, considering an exit path of the water from the mixing device. The choke valve 7a is housed in a housing chamber 7b the opening of which is arranged in proximity to the top portion of the case 2. The housing chamber 7b and the flowrate adjusting means 7, during normal operation, are hidden from the view of the user by a removable cover 7c. The removable cover 7c can be removed by the maintenance operator, i.e. by the operator assigned to the disinfection operation, to adjust the flowrate of hot water during the anti -Legionella thermal disinfection cycle.

[0042] In the illustrated embodiment, the housing chamber 7b extends substantially parallel to the longitudinal axis L of the case 2.

[0043] In the illustrated embodiment, the flowrate adjusting means 7 comprise a screw-nut screw mechanism, that is rotatingly-slidingly adjustable by an adjusting tool, like for example a screwdriver. In this embodiment a choke element 7a obtained in the screw can adopt an open position Tl, in which the transit of a water flowrate is permitted, the flowrate being for example equal to what is normally dispensed during normal operation, i.e., a rated flowrate of the electronic thermostatic mixing device 1, 1’ (Figure 9). Further, the choke element 7a can adopt a choke position T2 in which a leak of the water is permitted (Figure 8). In the illustrated embodiments, the flowrate adjusting means 7 are arranged in the case 2 to intercept the water exiting the thermostatic cartridge 4 and entering a pre-dispensing chamber 13. The pre-dispensing chamber 13 can be placed in fluid communication with the mouth portion 3 and thus with the outside of the electronic thermostatic mixing device 1, 1’ by the automatic activation device 5, in particular by the electrovalve 5b.

[0044] In addition to the positions disclosed, the choke element 7a can also adopt a further choke position T3 (Figure 10) in which the choke element 7a comes to abut on the narrowing section 11 to decrease the transit of water in the pre-dispensing chamber 13 with respect to the choke position T2. The further choke position T3 corresponds to a position of the choke element 7a in which the minimum water flowrate for thermally disinfecting is obtained. By way of non-limiting example, this minimum flowrate can be comprised between 0.5 and 1 1/min.

[0045] In one embodiment that is not illustrated of the mixing device the predispensing chamber 13 can be connected directly fluidly to the mouth portion 3 and thus to the outside.

[0046] The flowrate 7 adjusting means enable in particular the hot water to be reduced that is dispensed into the anti -Legionella thermal disinfection cycle, thus reducing the waste of resources (water) and the energy waste due to heating of the water.

[0047] The thermostatic cartridge 4 comprises, in particular, a pin element 4h provided at one end with an abutting portion 4e arranged for contacting, and thus receiving the thrust from, a thermally sensitive actuator 4b as will be explained below. During normal operation, the pin element is kept in position by an elastic overtravel element 6a.

[0048] The thermostatic cartridge 4 comprises, in particular, a plug 4c which is movable against an abutting seat 2c (hot seat) to prevent/limit the transit of hot water. The plug 4c is pushed far from the abutting seat 2c by an elastic element 4d and is actuatable to approach the abutting seat 2c through the effect of thermal expansion of a thermally sensitive actuator 4b caused by an increase in water temperature. In heat dilation, the thermally sensitive actuator 4b is contrasted by the elastic element 4d. The elastic element 4d is arranged for removing the plug 4c from the abutting seat 2c so as to enable the hot water to transit. In this condition of thermal dilation, the thermally sensitive actuator 4b pushes against an abutting portion 4e of the thermostatic cartridge 4.

[0049] The plug 4c is further movable against a further seat 2d (cold seat) to prevent/limit the transit of cold water. The plug 4c is actuatable to approach the further abutting seat 2d through the effect of the thrust of the elastic element 4d and of the thermal contraction of the thermally sensitive actuator 4b caused by a lowering of water temperature. The plug 4c is positioned, and is movable, between the abutting seat 2c and the further abutting seat 2d until it contacts the abutting seat of the further abutting seat 2d so as to adjust the transit of hot and cold water.

[0050] The elastic element 4d can comprise a spring.

[0051] The disinfection unit 6 comprises, in particular, a disinfection activation tool 8 arranged for intervening on, and disabling, the thermostatic cartridge 4 so as to allow only hot water to transit through the conduits of the case 2 until it flows to the outside through the mouth portion 3. The disinfection activation tool 8 is configured to act in direct contact on the thermostatic cartridge 4. With reference to Figures 8, 9 and 10, the disinfection tool 8 can be inserted at least partially into the housing cavity 2e to interact with a pin element 4h of the thermostatic cartridge 4. Precisely, the disinfection activation tool 8 can make contact with the pin element 4h to vary the position thereof. [0052] The disinfection activation tool 8 is configured, in particular, to disable the thermally sensitive element 4b so that an increase in water temperature does not cause the plug 4c to move to the abutting seat 2c and therefore prevent the transit of hot water (that is necessary to the thermal disinfection operation).

[0053] In the illustrated embodiment, the disinfection activation tool 8 comprises at one end thereof a contact portion 8a. The disinfection activation tool 8 comprises at an end opposite the contact portion 8a an actuation portion 8b. The actuation portion 8b can comprise a knob (as in the example shown). In an alternative embodiment the actuation portion 8b can comprise a bar or another type of lever. The contact portion 8a can comprise a screw thread.

[0054] The pin element 4h is inserted into the housing cavity 2e and is fitted in opposition to the plug 4c. Between the pin element 4h and the plug 4c, the thermally sensitive element 4b is positioned. The pin element 4h is provided with a coupling cavity 4f at an end opposite the abutting portion 4e. The coupling cavity 4f is arranged for coupling with the contact portion 8a of the activation tool 8. The disinfection activation tool 8 can be inserted at least partially into the coupling cavity 4f adopting an insertion position U, U1 (Figures 3 and 8). The coupling cavity 4f can comprise a nut screw thread. [0055] The pin element 4h (or the coupling cavity 4e) can be covered by a cover element 6c, 6c’, in particular during normal operation. The cover element 6c, 6c’ can be arranged at the opening of the housing cavity 2e. The cover element 6c, 6c’ is connected to the housing cavity 2e and is removable to provide the disinfection activation tool 8 with access to the housing cavity 2e to disable the thermostatic cartridge 4 and allow only hot water to circulate inside the case 2.

[0056] In the illustrated embodiments of the electronic thermostatic mixing device 1, 1’, the cover element 6c, 6c’ is fittable to, and removable from, the adjusting means 9.

[0057] The disinfection activation tool 8 can be driven manually during the thermal disinfection operation, so that the contact portion 8a removes the pin element 4h from the plug 4c, i.e. so that the force exerted by the elastic element 4d acts prevalently on the plug 4c. In this condition, the plug 4c is moved (by the elastic element 4d) far from the abutting seat 2c thereby allowing hot water to circulate even if the thermally sensitive actuator 4b is expanded. In addition, the plug 4c is moved (by the elastic element 4d) against the further abutting seat 2d to prevent the transit of cold water. The activation tool 8 can be actuated by rotating the actuation portion 8b. [0058] The coupling between the contact portion 8a of the disinfection activation tool 8 and the coupling cavity 4f can be a shape coupling, for example a grooved coupling, in particular a screw-nut screw coupling.

[0059] In use, in order to start the anti-Legionella thermal disinfection cycle, the disinfection activation tool 8 can be coupled with the pin element 4h of the thermostatic cartridge 4 (insertion position U, Ul). Subsequently, the disinfection activation tool 8 can be activated by rotating the actuation portion 8b to remove the pin element 4h from the plug 4c and enable the elastic element 4d to move the plug 4c against the further abutting seat 2d; in this situation the thermostatic cartridge 4 and the disinfection activation tool 8 adopt a disinfecting configuration U2 (Figures 9 and 10). In the disinfecting configuration U2, the elastic overtravel element 6a is compressed.

[0060] In the insertion position U, Ul, the presence of the disinfection activation tool 8 that protrudes from the case 2 makes it clear to an outside observer that the thermal disinfection operation (or the thermal disinfection cycle) is running and that the mixing device is in “not-in-service” status.

[0061] At the end of the thermal disinfection cycle, the disinfection activation tool 8 can be extracted and the disinfection actuation device 14a can be actuated to restore normal operation. Once the disinfection activation tool 8 is extracted, the elastic overtravel element 6a pushes the pin element 4h to the normal operation position.

[0062] During the thermal disinfection cycle, the disinfection activation tool 8 cannot be removed. Removing the disinfection activation tool 8 enables normal operation conditions, i.e. prevents the user being scalded by the escaping hot disinfecting water.

The automatic activation unit 5 and/or the control unit 14 are powered by means of a transformer unit 15 that is connectable to the electricity grid or by means of a battery assembly 16. In one embodiment that is not illustrated, the control unit 14 and/or the automatic activation unit 5 can be connected directly to one or more electric batteries.

[0063] The electronic thermostatic mixing device 1, 1’ comprises, in particular, temperature adjusting means 9, 9’ configured to interact with the thermostatic cartridge 4 to vary the mixing temperature so as to enable the user to adjust the mixed water dispensing temperature. In particular, the temperature adjusting means 9, 9’ are configured to vary the stroke of the thermally sensitive actuator 4b so as to limit or promote the transit of hot water. The temperature adjusting means 9, 9’ can comprise a screw-nut screw unit.

[0064] In the mixing device indicated by reference number 1 (first embodiment), the temperature adjusting means 9 are actuatable by an adjusting knob 9d directly by the user. In the illustrated embodiment, the knob 9d can comprise a lever for facilitating actuation by the user. In this embodiment, the user thus has the option of varying at will the mixed water dispensing temperature, in particular during normal operation.

[0065] In the electronic thermostatic mixing device indicated by reference number 1’ (second embodiment), the temperature adjusting means 9’ are hidden from the user during normal operation by a lid element. In the illustrated embodiment, the further lid element corresponds to the cover element 6c’. In one embodiment that is not illustrated, the further lid element can be an object that is distinct from the cover element 6c’. In this illustrated embodiment, the temperature adjusting means 9’ are actuatable by an adjusting key 10 by the maintenance operator (or by the fitter) of the mixing device. In this embodiment, accordingly, the user in particular during normal operation cannot change the mixed water dispensing temperature. The adjusting key 10 comprises at a first end thereof one or more adjusting protrusions 9b’ arranged for coupling with the thermostatic cartridge 4 to vary the stroke of the thermally sensitive actuator 4b.

[0066] The adjusting key 10 comprises at a second end thereof opposite the first one or more release protrusions 9a’ shaped to interact with a safety element 9c' (Figures 19, 20 and 21). The safety element 9c' can comprise a ring nut engaged (for example screwed) with temperature adjusting means 9’ to prevent tampering with the temperature adjusting means 9’. In one embodiment that is not illustrated, the safety element 9c' and the respective one or more release protrusions 9a’ may not be present.

[0067] With reference to Figures 11, 12, 13 and 14, one version of the first embodiment of the mixing device 1 comprises a mouth portion 3 that protrudes noticeably from the case 2. In particular, in this version the mouth portion 3 extends transversely, in particular orthogonally, to the longitudinal axis L of the case 2, from the top portion of the case 2.

[0068] With reference to Figures 15, 16, 17 and 18, one version of the second embodiment of the electronic thermostatic mixing device 1’ has a mouth portion 3 with a structure that is similar to, in particular the same as, that of the version of the first embodiment.

[0069] As mentioned the first embodiment and the second embodiment (and thus also the version of the first embodiment and the version of the second embodiment) differ from one another by the presence of the adjusting knob 9d, thus by the possibility for the user to adjust the temperature directly.

[0070] The electronic thermostatic mixing device 1, 1’ can implement a method for thermally disinfecting.

[0071] This method for thermally disinfecting comprises a step of removing the cover element 6c, 6c’ (Figure 2) to provide access to the housing cavity 2e containing the thermostatic cartridge 4, inserting into the housing cavity 2e the disinfection activation tool 8 (Figures 3, 8, 9 and 10) to disable the thermostatic cartridge 4 and permit only hot water to transit through the conduits inside the case 2 until it flows to the outside through the mouth portion 3. This step, in other words, involves mechanical disabling of the thermostatic cartridge so that the flow of hot water from the hot water 2a inlet is not prevented by the thermostatic cartridge 4. As mentioned, the thermostatic cartridge 4 can be disabled mechanically by the disinfection activation tool 8, enabling the plug 4c to prevent the transit of the cold water (at the further abutting seat 2d) and enable the hot water (at the abutting seat 2c) to transit.

[0072] The method of thermal disinfection further comprises a step of starting an antiLegionella thermal disinfection cycle by first disabling the automatic activation device 5 and activating an electrovalve 5b so as to dispense only hot water for a water dispensing duration that is necessary for performing a complete anti-Legionella thermal disinfection cycle. The water dispensing duration in the thermal disinfection operation is independent of the preset period of time associated with the automatic activation device 5 for dispensing water mixed during normal operation. In particular, the water dispensing duration in the thermal disinfection operation is greater than the period of mixed water dispensing time during normal operation.

[0073] The method of thermal disinfection comprises, in particular, a step of disabling mechanically the thermostatic cartridge 4 so as to permit only hot water to transit into the case 2 and into the mouth portion 3.

[0074] The method of thermal disinfection comprises, in particular, a step of adjusting the flowrate of hot water circulating during the anti-Legionella thermal disinfection cycle (or during the disinfection operation) by acting on the flowrate adjusting means 7.

[0075] The step of adjusting the flowrate during the anti-Legionella thermal disinfection cycle comprises, in particular, a step of decreasing the flowrate of hot water dispensed with respect to the flowrate of mixed water that is dispensable during normal operation (by taking the flowrate adjusting means from an open position T1 to a flowrate choking position T2, or as far as a further flowrate choking position T3, Figures 9, 8 and 10).

[0076] As can be seen from what has been disclosed above, the mixing device and the method of thermal disinfection according to the present invention enable the limits and drawbacks of the devices of the prior art to be overcome, successfully achieving the set objects.

[0077] The solution according to the present invention, owing to the integration of the automatic activation device 5 together with the thermostatic cartridge into the case 2, enables a mixing device to be provided that is compact and easy to install in relatively confined environments.

[0078] Further, owing to the possibility of disabling mechanically the thermostatic cartridge 4 by the disinfection activation tool 8, using a further valve arranged for diverting disinfection water in the conduits inside the mixing device is avoided. Using the same thermostatic cartridge 4 both for normal operation and for the disinfection operation enables a reduced number of components to be used and the overall risk of malfunction of the electronic thermostatic mixing device and relative maintenance costs to be reduced.

[0079] Further, the visibility of the disinfection activation tool 8 enables the fact that the disinfection operation is running to be signalled clearly, decreasing the risk of a user being involuntarily scalded.

[0080] The electronic thermostatic mixing device and the method of thermal disinfection according to the invention, owing to the configuration of thermal disinfection unit 6, enable the dispensing time to be extended simply that is necessary to perform the anti-Legionella thermal disinfection cycle completely. In other words, owing to the control unit 14 and/or to the disinfection actuation device 14a, the user (i.e. the maintenance operator) can increase the dispensing time of the hot water without having to continuously (or repeatedly) actuate the sensor to enable the hot water to perform the bactericide function. As a result, the thermal disinfection operation is more convenient for the maintenance operator by reducing inefficiencies and downtime of the washing station/s.

[0081] Also, owing to the flowrate adjusting means 7, the electronic thermostatic mixing device and the method according to the invention enable water waste to be reduced during the disinfection operation.

[0082] Further, owing to the particular configuration of the disinfection activation tool 8 and of the thermostatic cartridge 4, in particular owing to the elastic overtravel element 6a, it is possible to return to normal operation without again adjusting/setting the water dispensing temperature. In other words, at the end of the disinfection operation, it is not necessary to carry out a new calibration of the thermostatic cartridge 4, because once the disinfection activation tool 8 is removed from the thermostatic cartridge, the temperature settings are restored. This is particularly useful in the electronic thermostatic mixing device 1’ according to the second embodiment, in which the user does not have access to temperature adjusting means.

[0083] From what has been set out above, it is clear that the electronic thermostatic mixing device and the method according to the invention successfully achieve all the set objects mentioned previously.

[0084] What has been disclosed and shown in the appended drawings has been provided by way of example of the innovative features of the electronic thermostatic device.

[0085] In practice, the materials, in as far as they are compatible with the specific use and with the respective single components for which they are intended, can be appropriately chosen in function of the requested requirements and in function of the available prior art. Possible variations on and/or additions to what has been disclosed above and illustrated in the appended drawings are possible.