Other advantages and features of the present invention will become clear from the following detailed description of one embodiment of the invention, with reference to the attached drawings in which:
With reference to the drawings, a dishwasher 10 comprises a cabinet 10a and a front door 10b. The cabinet and the door define a washing chamber 12 having a bottom wall 12a where there is an opening for feeding salt used by the water-softening device for the regeneration of the ion exchange resins. In
On the door 10b a detergent distributor 16 is shown, near a distributor 18 for liquid rinse aid. The detergent distributor 16 is provided with an elongated rotating lid 16a covering three chambers 20, 22 and 24. The chamber 20 is intended for loading traditional powder detergent, and it may also be provided with a pre-wash basin. Chamber 22 is intended for loading tablets of solid detergent having also an additive performing a rinse aid function at the end of the washing program (the so called “2 in1” tablets). Chamber 24 is intended for loading tablets of solid detergent having additives performing a rinse aid function and a water softening function (the so called “3/4/5in1” tablets). For prompting the user to load the tablets in the correct chamber, chambers 22 and 24 present an indication 22a and 24a respectively (either on the bottom of the chamber, as shown in the drawings, or on the lid 16a) clarifying the purpose of each chamber. Therefore the user has no problem of loading the tablet in the correct chamber.
Each of chambers 22 and 24 presents a side wall 22b and 24b respectively made of flexible rubber like material so that, in the closed configuration of the door 10b, such side wall may be deformed by the weight of the solid detergent tablet if present in the chamber. This configuration is shown in
Similarly, when the micro-switch sensor indicates the presence of a “3in1” composition in the chamber 24, the machine automatically chooses a specific program sequence which prevents the activation of the rinse aid distributor 18 and prevents any regeneration of the resin of the water softening device, therefore bypassing such device.
Also the chamber 20 for powder detergent may be provided with a sensor as well; in order to reduce the cost of the machine such sensor is not strictly necessary since when sensors of chambers 22 and 24 indicate that no solid (tablet) detergent composition is present, the central process unit of the machine assumes that the user has loaded a powder detergent in chamber 20. A sensor in chamber 20 can guarantee that the machine does not start the washing program if no detergent is present, and an error message is set on the display accordingly.
Instead of using a micro-switch sensor, other sensors may be used as capacity sensors, foil switch sensors, reed sensors and the like.
As an alternative, each chamber 20, 22 and 24 may be provided with its own independent lid, and a micro-switch sensor can sense the closure of each lid. This system is very simple and such simplicity may counterbalance the disadvantage of a false signal when the chamber is closed but no detergent is placed in the chamber itself.
When a 3/4/5in1tablet is used, it is important to distinguish between a situation in which the water-softening device may be kept idle and a situation in which this could cause a not satisfactory washing performance. In other words, if the water hardness is higher than a predetermined value, for instance about 22° dH, the water softening properties of the 3/4/5in1composition is not enough for eliminating the water hardness and in this case the central process unit of the machine sets the regeneration/softening device accordingly and/or avoid a full by-passing of the water softener. When the machine has a switch for inputting the water hardness or it has a sensor for detecting automatically the hardness of water fed to the machine, the central process unit has stored therein a list of values corresponding to different rates of resin regeneration or water-softening by-passing. Such central process unit receives also signal from the sensors associated to the detergent distributor chamber 24. By combining the above information the central process unit can choose a specific rate of resin regeneration (and/or a specific degree of water softening device bypassing) in order to guarantee the proper water softening in the machine.
The processor or central process unit of the machine can have a sort of “head-up” table according to which, when a solid detergent composition having also water softening properties is used, deactivates any resin regeneration only if the hardness of water fed to the machine is lower than a predetermined value, for instance lower than about 21° dH. For higher value the central process unit chooses a predetermined degree of resin regeneration capable of supporting the insufficient water softening properties of additives in the detergent solid composition.
With a dishwasher as the one described above the user needs only to put the detergent composition in the right place (chamber); all the other selections or adjustments are carried out automatically by the machine.
Number | Date | Country | Kind |
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EP06120384.0 | Sep 2006 | EP | regional |