AU2003204196A1

AU2003204196A1 - Dishwasher and method for the operation of a dishwasher using a detergent composition containing several active substances

Info

Publication number: AU2003204196A1
Application number: AU2003204196A
Authority: AU
Inventors: Klaus-Martin Forst; Stefan Fuglein; Karlheinz Kohles; Rolf Stahlmann; Winfried Steiner
Original assignee: Electrolux Home Products Corp NV
Current assignee: Electrolux Home Products Corp NV
Priority date: 2002-05-16
Filing date: 2003-05-14
Publication date: 2003-12-04
Anticipated expiration: 2023-05-14
Also published as: ES2235126T5; EP1362547B1; ES2268568T3; EP1362547B2; EP1362547A3; DE50303969D1; EP1362547A2; ES2235126T3; AU2003204196B2

Description

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION NAME OF APPLICANT(S):: Electrolux Home Products Corporation N.V.

ADDRESS FOR SERVICE: DAVIES COLLISON CAVE Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

INVENTION TITLE: Dishwasher and method for the operation of a dishwasher using a detergent composition containing several active substances The following statement is a full description of this invention, including the best method of performing it known to me/us:- P-10078 CS/Le 01.04.2003 Description The invention relates to a dishwasher according to the preamble of Claim 1 and two methods for the operation of a dishwasher according to the preamble of Claim 10 as well as the preamble of Claim 13.

For some time so called "3inl compositions" have been available for the use in dishwashers which comprise a cleaning substance, a softening substance and a rinsing substance and which are simultaneously introduced into the wash tub or chamber of the dishwasher at a certain point of time in the cycle. These ,,3inl" compositions are available in the form of pressed tablets, so called ,,3inl tabs" and also as a,,3inl" powder. The ,,3inl compositions" can be inserted into dosing devices provided in the dishwasher and in such a case they are metered into the tub at a certain point of time which is determined by the wash program of the dishwasher. On the other hand they P-10078 CS/Le 01.04.2003 2 can also be inserted into the dishwasher by the user of the dishwasher, for instance into the cutlery basket, prior to switching on the wash program. Generally today the user has at his disposal more than one selectable wash program for washing the dirty items placed into the dishwasher. Several programs can be selected as wash programs known under such descriptions as quick program, normal program, intensive program and economy program for which terms a variety of synonyms exist. Ever since the commencement of the use of ,,3inl" compositions by the users of dishwashers, the customer complaints received by the manufacturers of dishwashers have significantly increased. The reason for this is that the cleaning and/or drying results of the articles washed in the dishwasher have to some extent dramatically deteriorated where ,,3inl" compositions are used by contrast to situations where traditional individual metering of the respective substances was used. A particular problem has been that the user does not observe the specific instructions regarding placement of the ,,3in 1" compositions into the dishwasher; some, for instance, place the ,,3inl" compositions into the tub of the dishwasher, whilst the manufacturer prescribes an exclusive use by means of a dosing device. At times the instructions from the manufacturers are not specific enough or inaccurate. A further problem is that whilst the user of the dishwasher generally knows which wash program he must select depending on the soil content of the wash load and the dryness/adherence of the dirt particles, he does not however have any intimate knowledge regarding the sequence of the wash program per se. This knowledge is usually taken for granted by the manufacturer of the ,,3inl" compositions who apparently totally disregards the fact that a variety of ,,3inl" compositions are available in the market, which in dependence of a variety of parameters dissolve differently and therefore achieve their highest efficiency at P-10078 CS/Le 01.04.2003 3 different points of time. Some of the available ,,3inl" compositions work according to the ,,dilution principle" (also known as the carry over principle), i.e. at the commencement of the cleaning the ,,3inl" composition is introduced and begins to dissolve. In this situation the rinsing agent is mainly added initially in a high concentration, i.e. overdosed, and it is assumed that due to it being carried over in wash water residues and by way of adhesion of the dissolved rinsing agent to the items to be washed, at the dishwasher tub walls and ceiling as well as in the supply lines, the concentration in the final (clear) rinsing process is still sufficient to achieve a particularly good drying result. A further type of the ,,3inl" compositions available has the feature that initially only the cleaning agent and the softening agent dissolve and the rinsing agent, which is encapsulated within the ,,3inl" composition for instance within a wax-covered pearl only dissolves during the final (clear) rinsing cycle depending on the temperature value and/or the pH value. When using a wash program which works with high temperatures already in the cleaning cycle of the program and/or when selecting a very long cleaning process, which usually goes hand in hand with intensive programs, the rinsing agent of the second type will then already be dissolved during the cleaning process. The rinsing agent of the first type in particular has the disadvantage where several program cycle processes are performed prior to the final (clear) rinsing process, such as cleaning and intermediate rinse cycles (with the latter being run between the cleaning and final rinse cycles), that the rinsing agent dissolves too soon and after several dishwasher water changes is no longer present in sufficient concentration during the final (clear) rinse program cycle. A further disadvantage when using the ,,3inl composition may arise where the user of the dishwasher, prior to the start of the wash program, adds the dose, for instance a P-10078 CS/Le 01.04.2003 4 ,,3inl tab by inserting it anywhere in the dishwasher, rather than into the dosing dispenser. In this case for instance at least the cleaning agent and softening agent begin to dissolve in the pre-wash rinse cycle, and laboratory tests have shown that the dissolution behaviour of the ,,3inl"compositions is even very good in water which essentially has the temperature prevailing in the supply pipes. Since the water is drained from the tub, the substances of the ,,3inl" composition are available in lower concentrations to the subsequent program processes of the cleaning, intermediate rinse and final (clear) rinse cycles. This has a direct effect on the cleaning result as well as the drying result of the dishes and generally impairs the result.

It is the object of the present invention to propose a dishwasher and two methods to operate a dishwasher, which overcomes at least one of the aforementioned disadvantages, and to provide a wash program, which is adapted to, or will be adapted to the use of dishwasher compositions containing several active substances, wherein the user will be enabled in principle to continue using the hitherto known wash programs.

A solution to the aforementioned task is provided by a dishwasher according to the characteristics of Claim 1 and a method each according to the characteristics of Claims 11 and 14.

In accordance with the device of the proposed invention, the user of the dishwasher is able to select at least one wash program, such as for instance an intensive program, P-10078 CS/Le 01.04.2003 normal program, quick program, economy program. The selection means are mostly in an operating panel of the dishwasher and are well known per se.

In accordance with the invention there is provided a switchable additional feature by which, upon the use of compositions containing several agents, such a use of a program control is displayed. The result of this is that the wash program which is selected by the user, such as intensive program, normal program, quick program, economy program is automatically adapted to the use of a composition which comprises in particular a cleaning substance, softener substance and rinsing substance.

This means that when the additional function is switched on, a corresponding signal is given to the control unit which automatically adapts the user-selected wash program to the use of the composition. For this purpose there are for instance stored in the microcontroller of the control unit various control sequence routines to fall back upon, and/or various parameters of the dishwasher program, such as temperature, duration of a certain dishwasher program cycle, wash solution fill volume, pH-value amongst others are defined and can then be accessed or changed by way of intervention. An alternative solution is offered by an additional function, wherein a switching means is switched off in accordance with the inventive operation. In a further embodiment of the invention there is an especially structured wash program for particular use with a composition which program can be selected specifically from amongst other wash programs.

Preferably, the additional function is designed for the use of a ,,3inl"composition, wherein this composition contains as active substances for the cleaning of the wash P-10078 CS/Le 01.04.2003 6 load essentially only a cleaning substance, softener substance and rinsing substance.

Independent of these constituents, the ,,3inl"composition can also contain further substances whose direct or indirect effect on the cleaning and drying result of individual wash program cycles or the total cleaning result of the wash program is of secondary importance. Insofar as further active substances of the composition are not expressly named, these are however known and embraced by the object of the invention.

Further, there is comprised a switching means for switching the additional function, which is preferably located in the control panel of the dishwasher besides other selection means and/or display means. A further option of arranging the switching means is being offered by the dosing device into which the composition is preferably filled. -For the design of the switching means a variety of known designs, such as rotary switches, contact switches or the like, are feasible. Furthermore, actuation of a switching means by way of user selection is also possible which can be added on by selection from a menu-driven selection device, for instance in a display type or in networked household appliances via a graphical interface or, optionally, a speech recognition system.

In the dishwasher there can be detected by means of at least one sensor being provided the use of a composition, in particular of a,,3inl"composition so that for the program sequence design it is distinguishable on the one hand whether a composition works according to the dilution principle or whether a composition is used which only dissolves the rinsing agent pH value-dependent or temperature-dependent in the P-10078 CS/Le 01.04.2003 7 rinsing phase. On the other hand, it is possible during the entire dishwashing program sequence to determine in repeated sensor measurements any concentration changes and/or pH value changes and/or hardness level changes of the wash solution which permit conclusions to be drawn regarding the concentration of the individual active substances of the ,,3inl"composition, with the consequence that the program sequence can be modified at any suitable point of time.

As regards sensors at least one of the sensors is designed as a chemical and/or acoustic and/or thermal and/or optic and/or pneumatic sensor type. Their employment can vary with regard to the number employed and their specific detection characteristics.

There is further an evaluation of the sensor signal with regard to the adaptation of the wash program sequence relating to the ,,3inl"composition, as well as for the design of the other parameters of the entire wash program sequence.

Furthermore, alternatively at least one chemical sensor proposed for the use with respectively selected receptors which is designed to detect several simultaneously present agents, such as cleaning agent and softening agent and/or rinsing agent, can detect the use of a composition and even without the additional function to the program sequence control being switched on can signalise the use of a composition.

Control measurements, optionally repeated control measurements, or comparison with other sensor measurements during the program allow detection of a composition used and the program is changed accordingly. Particularly preferred is at present the use of one sensor, which detects at least the pH value and/or the temperature and/or the degree of hardness of the dishwasher solution.

P-10078 CS/Le 01.04.2003 8 The proposed sensor(s) ascertain continuously or discontinuously during the program or during individual program cycles whose time frames or points of time can be preset, individual program parameters, for instance by means of an actual/desired value comparison and/or a differential value and/or the changed course of a parameter such as pH value, temperature, turbidity, foaming, concentration, water hardness, and whether a certain agent of the composition for instance exceeds or falls below a predetermined minimum or maximum value. Furthermore, for instance depending on a differential value, which for instance can be manufacturer-dependent and result from the ,,3inl"composition itself, as also with regard to other typical parameters such as concentration jumps, dissolution temperatures or parameter combinations such as pH value and concentration or concentration and temperature of the wash program. For a selectable time segment of a wash program or over the entire duration of the wash program, the change of at least one parameter of the wash program is recorded and evaluated. It is for instance possible with regard to the course of the pH value of the wash solution to draw conclusions on the concentration of the individual active substances of the ,,3inl"composition. Thus, at present the evaluation of the pH value can be performed in such a manner that the cleaning program cycle represents a max.

alkaline pH value and must either fall below a specified value in the final (clear) rinse program cycle or the course of its change is predefined, for instance in a specified family of characteristics within specified tolerances, or pH value jumps are ascertained within predefined time frames or otherwise time constants for their occurrence are ascertained, for instance after reaching the dissolution temperature of an encapsulated rinsing agent. In accordance with the invention, whilst an additional function for the adaptation of a wash program to the use of a composition is switched P-10078 CS/Le 01.04.2003 9 on, such sensor measurements are employed in any case for the active intervention into the program. When selecting a specially designed wash program these initially have a kind of control function to determine whether, during the program sequence, a composition is actually being used or at least an active substance is present in sufficient concentration at the preset time. Adjustments of the program are optional.

A suitable method for the evaluation of the sensor measurement signals is for instance to ascertain the value or the change of certain parameters of the wash program such as turbidity, pH value, foaming, concentration, water hardness and others individually as well as in suitable combination, at characteristic points of time of the wash program sequence, with regard to their quality and quantity and their respective delay times.

For this purpose at least individual parameter values can be ascertained and subjected to an actual-desired value adjustment, a differential value formation or a threshold value interrogation or the changes can be made against preset values or values ascertained during the program sequence. All reference values are backed up in tables or as default values in at least one memory unit of the program control. In networked household appliances this memory unit can also be located outside the dishwasher.

Furthermore it is also possible to store in the memory unit certain program statuses whose combination pairing is not desirable for instance and these can prompt the user to undertake certain actions. Such not desirable constellations arise for instance in the pre-wash rinse program cycle when an increased foaming and/or distinct pH value fluctuations occur or when the rinsing agent concentration falls below a preset value during all the program cycles or rinsing agent concentration jumps occur independent of a certain temperature or temperature variation. Depending on the error situation, the P-10078 CS/Le 01.04.2003 user can for instance be prompted to place a composition into the dosing compartment or the program sequence is interrupted until the user restarts the dishwasher or the measuring result detected as erroneous is at least displayed.

The program cycles pre-wash rinse or cleaning can be designed such that the point of time of the actual addition of the ,,3inl"composition is additionally monitored, for instance in that the fall of a tablet from the dosing device into the dishwasher tub is detected by an acoustic sensor. Other detection options are optical sensors, which for instance register increased foaming, or chemical sensors which evaluate the change in the pH value of the wash solution.

A further advantage is offered if, when using a composition which may be modified which comprises for instance an enzymatic cleaning substance with an effectiveness temperature limit of approx. 30 0 C and a rinsing substance with a dissolution temperature of approx. 58 0 C and at the same time applying preset shortened program cycles and consequently reduced dissolution periods, the wash solution is heated by way of short, optionally repeated, switching on and/or controlled power output of the heating means during the pre-wash rinse and/or intermediate rinse cycles, preferably at the end of the respective cycle so that for the following cycles, cleaning or final (clear) rinse, which are run with hot wash solution, the respective chemical substance is able to develop its effectiveness in an improved manner and for a longer time frame. By the preheating or increased heating of the wash solution at the end of the preceding wash program cycle the dissolution and therefore the P-10078 CS/Le 01.04.2003 11 effectiveness of the cleaning agent or rinsing agent is improved for the duration of each program cycle. The energy thus supplied is comparable to an activation energy.

When a temperature control is proposed, the dissolution period, concentration, action time, point of time of release of a chemical substance of the ,,3inl"composition can be optimised.

It is of particular advantage in this situation, when the actually used ,,3inl"composition is specified as a parameter in the program control, for instance by input via an image recognition, which for instance recognises the bar code of a ,,3inl "composition, or by selection from commercially available ,,3inl "compositions stored in the program memory or by input of a specified composition by the user in some other manner, where the user-specified information regarding the use of a certain ,,3inl composition is stored until a different input of information is made or is again interrogated at the commencement of each or any specifically defined point of time.

A further advantage being offered at the time of the interrogation or evaluation of an information regarding the type and form of administration of the dispensed cleaning, rinsing and, if required, softening agents, is that a product which is clearly not identified as a ,,3inl"composition can switch off a ,,3inl" function erroneously selected by the user or that, upon selection of a ,,3inl" program, an error message will be issued.

P-10078 CS/Le 01.04.2003 12 It is further advantageous that when the ,,3inl" function is switched on or when a ,,3inl wash program is selected, the display for statuses of the wash program, which in traditional wash programs with individual metering of the substances are switched on, are switched off or disabled, such as for instance switching off an LED at the time of the regeneration process or an LED which is the prompt for refilling the rinsing agent.

When after the dirty wash load has been filled into the dishwasher a wash program is selected by the user of the dishwasher, a composition is placed into the dishwasher, and by an optionally added-on selection means the use of a composition is displayed, the program sequence control will take into account the additional function and will determine that the program sequence of the selected program is changed and in its entire lay-out adapted to the use of the composition.

In this situation, depending on the selected program, individual or more parameters of the different program cycles, pre-wash rinse, cleaning, intermediate rinse, final (clear) rinse, are automatically adapted in the manner described below or changed in fixly preset manner essentially depending on the evaluation of preset sensor measurements.

The steps described in the claims do not represent with regard to their sequence an inevitable requirement for the program sequence, but can, for instance be selected specifically in dependence of the use of a certain composition or type of composition; they can be repeated and/or switched consecutively or can be followed by other program steps which are known per se.

P-10078 CS/Le 01.04.2003 13 When the "3 in 1" composition is used in situations where dosing devices with usually divided storage chambers for the cleaning substance and the rinsing substance are in place, the metering function for the rinsing agent or the metering function for the cleaning agent is disabled in the selected wash program. In an alternative lay out, where for instance the detection of the concentration of the rinsing agent is sensordependent, it is possible to subsequently add the required quantity of rinsing agent, thereby compensating for any dilution losses experienced during the preceding wash program cycle. Insofar as, during the selected wash program, further opening times are preset for the dosing device for the purpose of releasing a variety of substances, these will be locked or the timing of the addition of a certain substance delayed and/or the dosing quantity altered.

In the event the composition comprises in addition to the cleaning substance and the rinsing substance also a softening substance, which obviates the need for a softening process in the dishwasher in the known manner by means of a softening device provided, then it is naturally not necessary to perform in the dishwasher the known method of regenerating the softener with saturated saline solutions (brine). Therefore, in the program sequence, the regeneration function, i.e. the addition of a defined brine volume into the softening device, which is otherwise intended at a defined point of time in the program sequence, is disabled. Alternatively, a hardness sensor can be provided to ascertain the water hardness of the wash solution. The water hardness actually prevailing in the dishwasher following the softening with the softening substance contained in the composition can then be monitored and, if necessary, the regeneration function of the softening device can be switched on in addition so that a P-10078 CS/Le 01.04.2003 14 partial softening of the water is performed via the softening device. Experience has shown that the softening properties of the softening substances contained in the ,,3inl"composition alone are not sufficient in hard water areas. It is therefore of particular advantage when the information regarding the hardness level of the actually used water arriving from the supply lines is included in the program sequence design.

The hardness level of the water can for instance be input by the user via a specially provided input function, for instance in the control panel, and be stored or can alternatively be set at a blending device where respective means pass on the value of the water hardness setting to the program control, and when the ,,3inl" function is switched on or the in 1" wash program is selected, the regenerating function and/or at least the blending of hard with soft water will be facilitated at least at a preset point of time.

It is proposed to continue with the previously used water supply via the softening device independent of its softening capacity which will be exhausted with increasing numbers of wash solution changes and depending on the hardness level of the supply water. All other alternatives for the water supply, though possible in theory, are only practical however, where compositions comprising a softening substance become the only available standard.

The water volume which may be stored in the storage container of the dishwasher and be defined for the regeneration function may alternatively, in particular in soft water areas, be used as a defined volume, as a whole or in portions, during the wash P-10078 CS/Le 01.04.2.- 3 solution-carrying program cycles for metering of predetermined wash solution volumes.

If during an introductory pre-wash rinse the use of a composition is detected by the sensor or the use of such a composition is indicated by way of an additional function being switched on, the duration of the initially intended pre-wash rinse cycle can be reduced to prevent the cleaning agents and rinsing agents also comprised therein from dissolving too soon; they will then be available in sufficient concentration during the cleaning or rinsing cycles. If, on the other hand, a program has been selected which involves two or more pre-wash rinse cycles with a complete change of water for each cycle, the cancellation of at least one pre-wash rinse which may result in running just one pre-wash rinse cycle, may prophylactically prevent, even without the sensor detection of a composition, that.a composition erroneously placed into the dishwasher instead into the dosing device dissolves too soon.

If, as described above, the pre-wash rinse cycle is reduced or completely omitted, the period where the water acts upon the load is reduced, the presoaking process of stubborn, dried-on soiling, which may have been adhering to the dishes for a long time, is thereby shortened or completely cancelled. In some cases of high levels of soiling, this is not conducive to a good cleaning result. In such cases therefore, the duration of the cleaning cycle is preferably prolonged by the time period by which the duration of the pre-wash rinsing cycle was reduced.

Thus, the presoaking of the dirt particles is at least partially moved forward into the cleaning cycle.

P-10078 CS/Le 01.04.2003 16 It is particularly preferred to reduce the number of intermediate rinse cycles between the cleaning and final (clear) rinse cycles to one intermediate rinse which essentially has the task of removing individual, still adhering dirt particles and chemical residues remaining after the cleaning process. It is of further advantage to operate the intermediate rinse with a reduced maximum wash solution volume as compared with the maximum solution volume proposed for the cleaning cycle so that the concentration of the dissolved rinsing agent is higher than it would be in the same wash solution volume as used in the cleaning process. If, during the cleaning cycle, the wash solution is diluted several times and/or if by a respective turbidity measurement a low level of soiling of the wash solution has been recognised, it may be possible to forego the intermediate rinse cycle altogether.

In the intermediate rinse cycle, which is operated with lukewarm wash solution and consequently does not involve active heating by switching on of heating elements provided, the energy supplied during the process cycles which are operated with hot wash solution is extracted. In order to design the program in an energy-saving and water-saving manner as described above and thereby increasing the concentration of the rinsing agent in the intermediate rinse cycle, it can be proposed by repeated switching on and off of the circulating pump with variable and /or presettable duration of the switched on or off status of the circulating pump, to introduce the wash solution into the tub and have it act upon the load in the manner of a ,,pulse rinsing". When switching off the circulating pump, the circulation of the wash solution and therefore P-10078 CS/Le 01.04.2003 17 the mechanical action of the wash solution upon the load is interrupted. This type of pulse rinsing can be briefly described by the following sequence: spraying, pause, spraying, pause, spraying, pause etc.

At the end of at least one process cycle, such as for instance the intermediate rinse, a dilution step can be proposed in dependence of the turbidity measurement and/or of the content of rinsing agent in the wash solution. The dilution step has the effect that a partial volume of the wash solution, which was used during the intermediate rinse is again used in the subsequent final (clear) rinse cycle and is mixed with fresh wash solution which is newly supplied. Due to the dilution step, the loss of rinsing agent, in particular, compared with a complete draining and refilling of wash solution is reduced. For this very reason, it is possible, independent of the measurement of the turbidity of the wash solution, to force a dilution step instead of a complete draining of the wash solution, for instance at the end of a wash cycle.

As a further or alternative step, it is preferred to reduce the temperature in the cycle preceding the final rinse, preferably in the cleaning cycle, to a temperature below the dissolution temperature of the rinsing agent, preferably below 58 0 C. In this way, for instance in a selected intensive program, which usually operates the cleaning cycle at temperatures between 58 and 70 0 C, it is prevented that, when using a composition with a temperature-dependent release of the rinsing substance, the latter may already dissolve in this cycle and therefore will be available in too low a concentration in the final (clear) rinse cycle.

P-10078 CS/Le 01.04.2003 18 In the final (clear) rinse cycle, the load is heated to a temperature of at least 580C for the subsequent drying cycle. This facilitates the temperature-dependent and possibly pH-value dependent dissolution of the rinsing agent.

It is advantageous, on the one hand, to determine the temperature levels of the wash solution during a selected wash cycle which is automatically adapted to the use of a composition, as discussed above, based on the dissolution temperatures of the individual chemical substances. On the other hand, in the interest of energy saving, if a pre-wash rinse is performed, the wash solution is not heated by switching on the heating means, so that the wash solution essentially has the temperature of the water supply. During the cleaning and final (clear) rinse cycles, the wash solution is actively heated following switching on of the heating means provided, and in the intermediate cycle is heated passively, i.e. by absorption of energy from the heat capacities of the dishwasher, clearly to a temperature below the dissolution temperature of a temperature-dependent rinsing agent.

Without restricting the invention, it is possible to have components of the dishwasher program with selection of "3inl" function either fully or partially run according to a defined preset program or fully or partially adapted in a suitable manner to the actual situation relative to a predefined situation, based on the detection and evaluation of certain parameters, for instance by means of sensors.

P-10078 CS/Le 01.04.2003 19 The addition of the "3inl function or the selection of a "3inl program can optionally also be added to networked household appliances which are independently operated by a central computer which is not located in the dishwasher.

Besides the already known selectable programs, such as normal, intensive, economy, quick programs, a special "3inl" program can be made available which from the outset is especially adapted to the use of compositions, in particular such compositions which at the same time contain cleaning, softening and rinsing agents. The "3in l"program is directly selected by the user of the dishwasher and is characterised by the essential process steps mentioned below. The sequence mentioned, which is however not an inevitable sequence of the process steps, presents a possible program sequence without the finishing cycle, the drying cycle: Alteration or switching off of the softening function of the regeneration device and/or alteration or switching off of the opening of specially assigned storage chambers of the dosing device for further individually stored chemical substances (cleaning, rinsing agent) and/or alteration of the dosage to be added of the individually stored chemical substances.

Switching off of display elements associated with functions which during the program sequence, at least through the program control, are from the outset, i.e. preset to be switched off, preferably by switching off the display "regeneration" whilst the regeneration function is switched off by the regeneration device and/or switching off P-10078 CS/Le 01.04.2003 the display "refill rinsing agent" when at least the automatic metering of the rinsing agent is switched off.

The pre-wash rinse is undertaken with cold water- its temperature depending essentially on the water supply temperature for an extremely short duration of between 2 and 5 minutes. During this time, mainly fresh soiling can be loosened and soiling which has been adhering for longer periods is presoaked and softened. When the load has a high level of soiling and depending on an optional turbidity measurement of the wash solution, one or several dilution steps of the wash solution can be proposed with one dilution step being proposed preferably at the end of the pre-wash rinse in view of the short duration of this pre-wash rinse. If, at the end of the pre-wash rinse no dilution step is provided, the wash solution is completely exchanged prior to the subsequent cycle.

The then freshly supplied wash solution, which can also be diluted and thus may be polluted to a certain degree, is now heated in the cleaning cycle to a temperature which is below the dissolution temperature of the rinsing agent, preferably between and 57 0

C.

The composition is introduced into the dishwasher tub by the dosing device preferably within the first third of the cleaning cycle unless the composition, prior to the start of the wash program, has been placed into the tub or into the cutlery basket by the user.

P-10078 CS/Le 01.04.2003 21 At the aforementioned temperature, the wash solution is circulated in the tub for approx. 10 to 30 minutes during the cleaning cycle and, at the end of the cleaning cycle, is either fully drained or diluted. This decision can be made depending on an optional turbidity measurement of the wash solution.

If at least one turbidity measurement of the wash solution is taken, it is optional to perform several dilution steps depending on the degree of soiling and/or the concentration of individual constituents of the composition. The cleaning cycle is followed by an intermediate rinsing cycle, wherein the now present fresh or diluted wash solution is passively heated, i.e. exclusively by energy extracted from heat capacities of the dishwasher, so that the wash solution during its circulation removes the last soil particles and chemical residues still remaining from the cleaning cycle.

The circulation of the wash solution in the intermediate rinse cycle is for a duration of approx. 2 to 10 minutes. Alternatively, the intermediate rinsing can also be performed by "pulse rinsing" employing a reduced wash solution volume relative to the maximum wash solution volume present during the cleaning cycle.

The intermediate rinse cycle is terminated with a complete or partial draining of the wash solution.

In the final (clear) rinse cycle a defined wash solution volume is supplied to the dishwasher tub. This can either be fixed from the outset and/or variably set depending on a variety of parameters. A dependent value in this situation is the concentration of the rinsing agent actually present in the wash solution, since this concentration P-10078 CS/Le 01.04.2003 22 directly affects the final (clear) rinse result and thus the subsequently achievable drying result of the load. Thus, in the case of a low concentration of the rinsing agent at the commencement of the final (clear) rinse program cycle, the wash solution is introduced at as low a volume as possible, however depending on the turbidity level of the wash solution. If however the concentration of the rinsing agent at the commencement of the final (clear) rinse cycle is above average or sufficiently high, the concentration of the rinsing agent can be adjusted to a predetermined concentration by way of a defined presettable wash solution volume being supplied.

The wash solution with already dissolved rinsing agent, as well as the solution with the rinsing agent still to be dissolved, is now preferably heated to a dissolution temperature above the dissolution temperature of a rinsing agent whose dissolution is pH value-dependent and temperature-dependent. This dissolution temperature is at present above 58 0 C (for the ,,3inl"composition Calgonit Powerballs®). For a duration of 2 to 15 minutes, however at least until a predetermined temperature is reached (at present preferably 65 to 70 0 the wash solution is heated and circulated.

At the end of the final (clear) rinse cycle, the wash solution is drained from the tub as far as possible by being pumped out.

Residual solution remaining on the wash load, the tub ceiling and the tub walls as well as steam are removed during the drying cycle, which follows the final (clear) rinse cycle. The drying process is preferably by way of condensation drying. During the condensation drying, preferably during the first third of this program cycle, at least one recirculating air blower, if available, is employed.

P-10078 CS/Le 01.04.2003 23 The intermediate rinsing during the wash solution-carrying cycles, can preferably be in the manner of pulse rinsing, i.e. that during the intermediate rinsing process the circulating pump is repeatedly switched on or off for a presettable or definable duration. In this case the duration of the switching on or off of the circulating pump is depending on a wash solution level in the tub, which corresponds to a lower fill level at which the circulating pump does not draw in any air. Based on the aforementioned limited factors there exist further dependencies to the speed of the circulating pump which with increasing number of revolutions draws more wash solution from the sump. The design of the switch on and off pulses is also settable in dependence of a turbidity measurement of the wash solution. Thus, where low soil content is present, the duration of the switched on state of the circulating pump relative to the switched off state of the circulating pump can be shortened and is respectively prolonged where a high soil content is present. In dependence of a pH-value measurement and/or the temperature of the solution and/or a detected rinsing agent concentration, the maximum wash solution volume during a wash solution-carrying cycle, preferably in the intermediate rinse cycle, can be defined. In this way the dissolution behaviour and/or the concentration of the rinsing agent and/or one of the other substances of the composition can be influenced. If a composition is used which contains a rinsing agent, which has a temperature-dependent and/or pH-value dependent dissolution behaviour, a defined pH-value, preferably in the neutral pH range must be reached during the intermediate rinsing. This presumes an increased wash solution volume during the intermediate rinsing as well as that this pH-value can be reached by one or more dilution steps provided during the intermediate rinsing.

P-10078 CS/Le 01.04.2003 24 The invention is described in greater detail by way of an embodiment example relating to the method for operating a domestic dishwasher which is suitable for the use of "3in 1" compositions, namely such compositions containing the agents such as cleaning substance, rinsing substance and softening substance.

The only figure shows a schematic view of the individual cycle processes of a dishwasher program sequence. It is assumed herein that the water supply is essentially soft and thus has a low degree of hardness.

The ordinate of curve A does not show the time true to scale and the abscissa does not show the wash solution volume present in the tub true to scale. Individual important parameters for the cycle sequence, which are indispensable for a particularly good cleaning result of the wash load, are identified by arrows. Preferably, at the commencement of the program, automatic dosing functions which do not comprise the addition of "3inl" compositions are disabled; this concerns in any case the automatic metering of the rinsing agent and, furthermore, the automatic regeneration function is disabled. As is shown in the figure, the dishwasher program comprises a pre-wash rinse of a very short duration of between 2 and 5 minutes at supply water temperature.

In this program cycle it is preferred not to add any chemical substances to the dishwasher to improve the pre-wash result. It can however not be prevented that the user may by mistake place the "3in l" composition into the dishwasher already prior to starting it. After complete drainage of the wash solution at the end of the pre-wash P-10078 CS/Le 01.04.2003 rinse cycle, marked by arrow VV, fresh wash solution is supplied to the tub. This is limited to a maximum wash solution volume provided of approx. 4 1 for a dishwasher designed for a load of 12 standard sets of dishes. At the beginning of the cleaning cycle, the wash solution is heated by switching on heating means provided. The wash solution shall reach a temperature of approx. 55CC which at the time of the invention corresponds to a temperature below the dissolution temperature of the rinsing agent in pH-dependent and temperature-dependent soluble "3inl compositions, such as for instance Calgonit Powerballs®. In the first third of the cleaning cycle, the "3inl" composition is added, preferably during the supply of the wash solution (marked by arrow "3inl").

The wash solution is circulated in the tub at the max. defined temperature and the wash load is subjected to this wash solution treatment for approx. 10 to 30 minutes.

At the end of the cleaning cycle, the wash solution is almost completely drained from the tub (marked by arrow VR). The wash solution volume is freshly filled up for a subsequent intermediate rinsing cycle and is heated exclusively by extracting energy which is stored in the heat capacities of the dishwasher and is then circulated. The max. supplied wash solution volume can be varied depending on a turbidity measurement and/or a concentration measurement of a rinsing agent which works according to the dilution principle. Thus, as shown by the dotted line, the wash solution volume is preferably increased for high soil levels and/or high concentration levels of the rinsing agent and/or a strongly alkaline environment of the wash solution.

At low levels of soiling, where a rather low concentration of the rinsing agent relative P-10078 CS/Le 01.04.2003 26 to the concentration necessary for the rinsing cycle and/or an already neutral wash solution are present, the wash solution volume, shown as a dashed line, is reduced.

The intermediate rinsing cycle, after a dilution step or after a complete draining (not shown) for instance depending on the turbidity level, passes over into the final (clear) rinsing cycle. During this cycle, the wash solution volume is at least partially increased and preferably reaches the maximum possible wash solution volume of the cleaning cycle. Alternatively, the wash solution volume can be set exactly to a defined concentration range of the rinsing agent based on evaluated measuring results of sensors in place. The value of the wash solution volume to be supplied must then be calculated by the computing unit of the program control. Thus the duration of the intermediate rinsing process varies between 2 and 10 min and the duration of the final (clear) rinse between approx. 2 and 15 min. During the sequence of the program, the temperature of the wash solution is then increased to above the dissolution temperature of a pH value-dependent or temperature-dependent rinsing agent. The dissolution temperature of the rinsing agent is at present at approx. 58 0 C, so that in the final (clear) rinse the wash solution is heated to a minimum temperature of between and 70 0 C. At the end of the final (clear) rinse cycle, the wash solution is almost completely drained from the tub (marked by arrow VK). The final (clear) rinse cycle is followed by a drying cycle, which is not shown in the figure.

Without hereby restricting the scope of the invention, all details relating to numerical values are adapted to presently commercially available "3inl" compositions (Calgonit P-10078 CS/Le 01.04.2003 27 Powerball®, Somat 3inl®, Sun 3inl Optimal®). In the event the compositions of these 3inl preparations are changed, the parameters with numerical values will have to be adjusted accordingly. For a further modification of the program sequences suggested, we refer to parallel applications P- 10073, Title "Method for the operation of a dishwasher" and P-10026, Title: "Method for the operation of a dishwasher, dishwasher" dtd. 16.05.2002, by the present applicant.

Without hereby restricting the invention, a program structure or a method is also feasible wherein the aforementioned invention is reversed, i.e. all the preset programs are designed for the use of ("3inl") compositions and by way of an activatable switching means an adjustment of the selected wash program to the use of an individually rationed or metered cleaning agent, rinsing agent and softening agent is possible.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

Claims

01.04.2003 28 THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. A dishwasher, where at least one wash program is selectable, characterised in that this wash program is itself defined for the use of a detergent composition comprising several active substances or where at least one means for connecting an additional function is provided, by which means upon switching on this function at least one parameter of the selected wash program can be changed with regard to the use of a composition with several active substances.
2. A dishwasher according to Claim 1 wherein the additional function is designed for a,,3inl"composition containing at least one cleaning substance, one softener substance and one rinsing substance, which is applied in the form of a pressed tablet, pearl or as a powder or liquid.
3. A dishwasher according to Claim 1 or 2, characterised in that a switching means for switching on an additional function is arranged in the control panel of the dishwasher or within or at a dosing device or at some other place.
4. A dishwasher according to any one of Claims 1 to 3, characterised in that at least one sensor is provided whose measuring values can be ascertained and evaluated specifically so that the run of the selected dishwasher program can be influenced and defined by the program control unit of the dishwasher and/or if required the program control initiates in a defined manner further sensor P-10078 CS/Le 01.04.2003 29 measurements and/or input-dependent interrogations before at least one defined intervention into the dishwasher program sequence occurs.
A dishwasher according to Claim 4, characterised in that at least one chemical and/or at least one acoustic and/or at least one optic and or at least one thermal and/or at least one pneumatic sensor is arranged within the dishwasher.
6. A dishwasher according to any one of Claims 4 or 5, characterised in that, continuously or discontinuously, based on at least one actual/desired value comparison and/or differential value and/or the change of at least one wash program parameter, pH value and/or temperature and/or turbidity and/or foaming and/or concentration, it is detectable to which extent with regard to quality and/or quantity the release of at least one specific substance of the composition has occurred.
7. A dishwasher according to any one of Claims 4 to 6, characterised in that points of time and/or time intervals for specific sensor measurements and/or desired values and/or threshold values and/or other comparative values for the evaluation of these sensor measurements are stored in at least one memory unit of the program control.
8. A dishwasher according to any one of Claims 4 to 7, characterised in that by at least one sensor provided, preferably at the commencement of the dishwasher program sequence or during the first wash solution-carrying program cycle it P-10078 CS/Le 01.04.2003 is detectable whether a composition has been placed into the dosing device or at some other place within the dishwasher, preferably into the cutlery basket, and/or that at least once in the sequence of the dishwasher program it is detectable by at least one measurement by a sensor whether a rinsing substance present in the composition has already been mixed into the wash solution at an earlier or at a defined point of time during the program sequence, or is preferably not released until a final (clear) rinse cycle, and/or whether the actual rinsing substance concentration has fallen below or has exceeded the defined concentration.
9. A dishwasher according to any one of Claims I to 8, characterised in that a recognition device, in particular an image recognition device is provided, by means of which the information regarding the use of a defined composition is ascertainable.
A dishwasher according to Claims 1 to 9, characterised in that at the dishwasher indicators are provided, which display the use of a composition and/or certain sequence statuses or the entire program sequence of a dishwasher program especially adapted to, or selectable for the use of a composition.
11. A method for operating a dishwasher, wherein at least one dishwasher program is selectable, which by optional switching on or off of an additional function for the use of a composition and/or upon an automatic, essentially sensoric P-10078 CS/Le 01.04.2003 31 detection of the use of a composition is adapted in its structure and in its sequence to the use of a composition having several active substances, characterised in that in the course of the wash program at least one of the following process steps is executed: a) the metering of certain substances which are stored in the dosing device is delayed with regard to its point of time and/or has the dosage quantity altered or is completely disabled; b) the automatic regeneration function of the regeneration device will be switched off unless it is detected by a hardness sensor provided that the actual degree of hardness has fallen below or has exceeded a defined degree of hardness and/or by a user-dependent input at the regeneration dosing device a defined degree of hardness of the wash solution is determined and/or via a program-controlled input device the regeneration function is enabled whilst the additional function is switched on, where upon exceeding a defined degree of hardness of the wash solution by means of at least temporary re-enabling of the regeneration function and/or blending of the wash solution with soft water, the degree of hardness of the wash solution as a whole is reduced; c) at the commencement of the wash program the metering of the rinsing substance from the dosing device is blocked, that for this purpose a P-10078 CS/Le 01.04.2003 32 respective default value is set and stored in a memory unit of the program control, where in the event of detection that the rinsing substance concentration has fallen below a definable concentration value, this default value is resettable and/or, at a definable point of time of the program sequence, a definable volume of rinsing substance can be added to the wash solution and/or until a definable minimum concentration value is achieved, where such an addition is preferably undertaken when the final (clear) rinse cycle is reached; d) during the program sequence and depending on the particular process run of the actually executed program cycle b) regarding the regeneration function an addition of a defined brine volume into a softening device is disabled or enabled; e) information regarding the actual status and/or desired status of at least one parameter of the wash program or a prompt derived therefrom and/or request to the user be indicated by corresponding indicators; f) the duration of at least one program cycle preferably of one pre-wash rinse cycle be reduced in time or reduced to zero; g) the duration of two process cycles, preferably of the pre-wash rinse and cleaning and/or cleaning and intermediate rinse cycles, are prolonged P-10078 CS/Le 01.04.2003 33 and/or reduced, whereby the duration of the prolongation and reduction are in a definable proportion; h) one or more proposed intermediate rinse cycles are reduced to one intermediate rinse cycle or none; i) at least in one program cycle by once only or repeated switching on and off of the circulating pump with variably definable or specifiable duration of the switched on and switched off status of the circulating pump or by controlled speed variation of the circulating pump, the wash solution is caused to act upon the wash load in the manner of pulse rinsing; j) during at least one program cycle preferably at the end of the pre-wash rinse, cleaning and/or intermediate rinse cycles, at least one dilution step for the reduction of the soil concentration of the wash solution in dependence of at least one measurement of the turbidity and/or the concentration of at least one active substance in the wash solution or independent thereof is undertaken; k) The max. temperature in the program cycles preceding the final (clear) rinse cycle, in particular in the cleaning cycle, to a temperature below the dissolution temperature of the rinsing substance reduced; P-10078 CS/Le 01.04.2003 34 1) In the final (clear) rinse cycle the solution is heated to a temperature which is above the temperature of the solution of the rinsing substance;
12. A method for operating a dishwasher according to Claim 11, characterised in that at least in the cleaning and final (clear) rinse cycle following switching on of heating means provided the wash solution is actively heated and, optionally in the intermediate rinse cycle the wash solution is preferably passively heated without these heating means being switched on and/or during the pre-wash rinsing the wash solution is essentially not actively heated.
13. A method for operating a dishwasher according to Claim, 11, characterised in that during the intermediate rinsing and/or pre-wash rinsing the heating means provided are switched on and off for a very short period, which is executed repeatedly in intervals of different or equal length below or close to the dissolution temperature of the cleaning substance and/or the softening substance and/or the rinsing substance.
14. A method for operating a dishwasher, which can be selected from amongst several dishwasher programs with defined program sequences as the dishwasher program for operating a dishwasher for the use of compositions with several active substances, preferably "3inl" compositions, characterised in that at least one process step according to the Claims 11 to 13 is executed or several of these process steps are consecutive or follow each other at intervals or are at least individually repeated. P-10078 CS/Le 01.04.2003 A method according to one of Claims 11 to 14, characterised in that at least one of the following process steps is fixly defined within the sequence of a dishwasher program adapted or selectable for the use of a composition: changing or switching off the softening function of the regeneration device and/or changing or switching off the opening of special storage chambers of the dosing device; switching off corresponding indicators relating to functions which during the program sequence at least by the program sequence control have been switched off from the outset, i.e. preset to be switched off; pre-wash rinsing with cold, water supply temperature dependent-wash solution with a pre-wash duration of preferably 2 to 5 minutes, complete wash solution change at the end of the pre-wash cycle, wherein one or more dilution steps with a wash solution change can be executed during the pre-wash rinse; heating of the wash solution in the cleaning cycle to a temperature which is below the dissolution temperature of the rinsing agent, preferably between 45 and 57 0 C; P-10078 CS/Le 01.04.2003 36 metering of the composition during the heating phase of the wash solution in the cleaning program cycle, preferably at the beginning or in the first third of the cleaning program cycle; circulation of the wash solution in the tub during the cleaning cycle at a cleaning temperature (40 to 57 0 C) for the duration of 10 to 30 minutes, where at the end of the cleaning process cycle the wash solution, optionally depending on the results of a turbidity measurement of the wash solution is completely drained or the cleaning cycle is terminated by a dilution step wherein several dilution steps can optionally be executed during the cleaning; passive heating of the wash solution in an intermediate rinse cycle which is freshly supplied or blended with wash solution of the cleaning cycle and circulation of the wash solution in the tub for a duration of 2 to 10 minutes; termination of the intermediate rinsing cycle with a complete or partial draining, where the latter introduces a dilution step to the following process cycle: filling up of the wash solution to a defined and/or variably settable fill level of the wash solution in the final (clear) rinse cycle.
Heating of P-10078 CS/Le 01.04.2003 37 the wash solution, by switching on of heating means provided to above the dissolution temperature of the rinsing substance of the composition, preferably to between 58 and 70 and circulation of the wash solution with the dissolved and "carried over" rinsing substance; complete draining of the wash solution from the tub at the end of the final (clear) rinse cycle, only after the concentration of the rinsing substance for a defined time period has not fallen below a defined time period at least in the final (clear) rinse cycle;
16. A method for operating a dishwasher according to Claim 15, characterised in that the circulating pump preferably in the intermediate rinsing cycle is repeatedly switched on and off for a presettable or definable duration, wherein the duration of the switching on of the circulating pump or the switching off of the circulating pump is depending on a wash solution level in the tub and/or the speed of the circulating pump in a turbidity measurement of the wash solution, wherein the maximum present wash solution volume is set depending on the temperature of the wash solution and/or the ascertained rinsing agent concentration and/or the pH value and/or the level of soil in the filter.
17. A dishwasher substantially as hereinbefore described with reference to the drawings and/or examples.
18. A method of operating a dishwasher substantially as hereinbefore described with reference to the drawings and/or examples.
19. The steps, features, compositions and compounds disclosed herein or referred to or indicated in the specification and/or claims of this application, individually or collectively, and any and all combinations of any two or more of said steps or features. DATED this FOURTEENTH day of MAY 2003 Electrolux Home Products Corporation N.V. by DAVIES COLLISON CAVE Patent Attorneys for the applicant(s)