GB2210256A

GB2210256A - Dishwashing/washing machines

Info

Publication number: GB2210256A
Application number: GB8817988A
Authority: GB
Inventors: Ulrich Deiss; Ruediger Eiermann; Helmut Jerg; Rudolf Schmidt
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-09-25
Filing date: 1988-07-28
Publication date: 1989-06-07
Anticipated expiration: 2008-07-28
Also published as: IT8822007A0; DE3732452A1; DE3732452C2; ES2010352A6; FR2620924A1; IT1227034B; GB8817988D0; GB2210256B; FR2620924B1

Description

0 IY 4 k PROGRAM CONTROLLABLE HOUSEHOLD APPLIANCE The present invention

relates to a household appliance controllable by a program.

In the case of water conducting household appliances, such as dishwashing or washing machines, it is known to fill the water quantity, needed for a section of a rinsing or washing program, in dependence on time into a rinsing or washing container of the machine. For this purpose, an electromagnetic valve, which is switched by program control apparatus of the machine and arranged in a water feed duct, is opened for a predetermined time. However, this time-dependent water filling control functions with sufficient accuracy only if a minimum pressure, for example 1 bar, prevails in the feed duct.

In the case of a lower water flow pressure, filling of the rinsing or washing container to the extent necessary for satisfactory functioning of the machine can no longer be guaranteed. In regions with especially low water pressure or without central water supply, such machines are no longer satisfactorily usable with a time-dependent water filling control.

In the case of a dishwashing machine disclosed in DE-PS 33 16 685 there is provided, for energy-saving rinsing of crockery with short program times and for accurate metering of the water and regenerating filling quantities, a fresh water duct which extends from a fresh.

water inlet valve and ends in a free flow path of a storage container which serves for the introduction of a metered brine quantity and is disposed above water softening equipment. From the free flow path, a conduit leads into a reservoir container thermally conductively connected with the rinsing container and acting as a heat exchanger.

1 1 The reservoir container is fillable with fresh water by the upstream storage container and is emptiable into the rinsing container by way of the ion exchanger. The volume of the reservoir container is sufficient for' filling the rinsing container for two rinsing operations. Accordingly, the size of the reservoir container or heat exchanger is relatively large. An outflow duct leads from the storage container to the salt reservoir container of the softening equipment. Final ly, associated with the storage container is a level transmitter to cause closing of the fresh water inlet valve when the reservoir container and storage container are filled. The level transmitter consists of an overflow chamber, separated from chambers of the storage container by an overflow separating wall and emptiable by means of siphon, in which is arranged a float which in a raised end setting actuates a switch for switching off the fresh water inlet valve. Arranged in the ducts of the storage container to the salt reservoir container and from the reservoir container to the ion exchanger or to the rinsing container are controllable, electromagnetic valves.

In DE-PS 31 44 866 there is disclosed, for accurate measuring and matching of the regenerating medium quantity to the locally pre- vailing water hardness, a storage container which is fillable on the supply of the fresh water to the machine and which has at least two chambers and a ventilatable valve. The content of the storage container can entirely or partly flow out over an overflow duct into a salt reservoir container for the introduction of a corresponding brine amount into an ion exchanger container.

In order to reduce assembly and manufacturing costs in the case of household dishwashing machines with softening equipment, a !Q k - 3 regenerating water storage container and a heat exchanger and to safeguard against leakage from ducts, it is known from DE-OS 35 22 901 to combine a reservoir container, which is thermally conductively connected with a rinsing container, an ion exchanger, a salt reservoir container, a storage container, a free flow path and a level transmitter into a unit. This unit is also of relatively large volume.

Finally, in DE-PS 27 16 252 there is disclosed a dishwashing or washing machine with program control apparatus and with equipment for release into a rinsing or washing container of a water quantity measured in a collecting container and fed by way of a valve-controlled duct. For that purpose, arranged under the collecting container, which holds a water quantity for a section of a rinsing or washing program of the machine, is a small volume overflow container, at the inlet side of which opens a siphon of large type crosssection extending from the collecting container, while at the outlet side the overflow container is connected with the rinsing container by way of an overflow sill and a siphon of small flow cross-section. Moreover, connected to the overflow container is a pressure element which, in dependence on the water pressure in the overflow container, opens, and again closes, the valve arranged in the duct to the collecting container to allow a total water quantity, amounting to a multiple of the water quantity measured in the collecting container, for a program section with water requirement to be fed to the rinsing or washing container of the machine, the program control apparatus of which then holds the valve closed until the start of a following program section.

There remains a need for a household appliance with a water feed system which is conveniently and compactly arranged in the machine - 4 housing, can be manufactured and assembled with reduced cost, is less susceptible to trouble, and enables accurate metering of the rinsing and regenerating water quantities independently of the influence of the water supply. Preferably, also, the water throughflow should 5 be able to be regulated with little control complication.

According to the present invention there is provided a household appliance controllable by a program with a plurality of sections requiring-operation of the appliance with water, the appliance comprising a rinsing container, water softening means comprising a salt reservoir and an ion exchanger, a water storage chamber disposed above the water softening means and connected at an outlet thereof to an inlet of the salt reservoir, a flat filling chamber arranged between the rinsing container and a wall of the appliance and connected at an inlet thereof to an outlet of the ion exchanger, a throughflow chamber connected at an inlet thereof by way of a siphon to an outlet of the filling chamber and at an outlet thereof to the rinsing container, fresh water feed means comprising an inlet valve and a feed duct which is connected to an inlet of the ion exchanger and which includes a free flow portion disposed to permit filling of the storage chamber, and control means responsive to water state in the throughflow chamber to so control opening and closing of the inlet valve as to permit supply to the rinsing container of the total volume of water, equal to a multiple of the volume of the filling chamber, required for operation of the appliance in one such program section, the inlet valve thereafter being controlled to remain closed until the next such program section.

The appliance may be a household dishwashing machine or other kind of water conducting apparatus, for example a washing machine.

An embodiment of the present invention will now be more particular ly described by way of example with reference to the accompanying drawing, the single figure of which is a schematic sectional view of a water feed system of a dishwashing machine embodying the invention.

Referring now to the drawing, there is shown part of a household dishwashing machine 1 which has an outer housing and contains a rinsing container 2, a salt reservoir container 3 and an ion exchanger 4 for water softening. Arranged between a side wall of the rinsing container 2 and housing 1 is a flat container unit 24, preferably of plastics material, which constitutes a substantial part of the water feed system of the dishwashing machine. The container unit 24 is connected to the mains water duct by way of a fresh water duct 9 downstream of a fresh water inlet valve 6, for example a safety valve (for example that disclosed in DE-OS 15 34 25 590) seated directly at a stop cock 42. The duct 9 extends upwardly in the container unit to a free flow path 7 similarly integrated in the unit. A conduit 10 extends downstream of the free flow path 7 to the ion exchanger 4 arranged under the unit, for example in the bottom space of the dishwashing machine. 20 Disposed in the upper part of the unit 24 and below the fre'e flow path 7 is a chamber which forms a regenerating water store 8. The store 8 is fillable with leakage water from the free flow path and/or with build-up water from the conduit 10 to the ion exchanger and/or by way of a connection from a filling container 5 provided under the store 8. A blockable outflow duct 11 leads from the store 8 to a more deeply arranged salt reservoir container 3. The store 8 is emptiable by way of a siphon passage 30 or 31 into the outflow - 6 duct 11. For the adaptation of the regenerating water quantities to the respective local water hardness, the siphon passages are connected by way of connections 43 and 44 with a water hardness switch 45 and are closed or opened in dependence on the setting of the switch 45. Through ventilation of either siphon passage the associated siphon is ineffective, so that the maximally usable regenerating water volume (overflow level 34 of the store 8) is reducible to an average volume (level 33) for regions with normal water hardness or to a small volume (level 32) for regions with small water hardness and thus the salt consumption can be reduced.

The unit 24 also includes a ventilating channel 20 with ventilation opening 46 serving for ventilation of the free flow path 7 and as an overflow for the store 8, wherein the ventilation channel passes over into a decending condensation and deaeration channel 21. A siphon loop 35, in which a water condenser is present, forms a steam lock therein. Below the steam lock or the siphon loop the channel 21 opens into an inflow shaft 22, which is connected to the rinsing container 2, for example with the interposition of a seal.

The unit 24 further comprises the container 5, which is fillable with water from the ion exchanger 4. The filling container 5 is' connected with a connection duct 19 at an outlet stub pipe 12 of the ion exchanger. The volume of the container 5 is, for example,such that three filling quantities of the container produce a rinsing water quantity for a program section "pre-rinse, clean, intermediate rinse or clear rinse". The volume of the container 5 can thus be restricted to, for example 1.5 or 2 litres and the unit 24 can be compact. The container 5 is emptiable, by way of a siphon 13 included in the unit 4 - 7 24 and with an overflow sill 14, into a low volume throughflow chamber 15 which is arranged in the unit 24 below the container 5. A connecting stub pipe 23 leads from the throughflow chamber 15 into an outflow sump 16 or into the pump pot of the rinsing container 2 of the dishwashing machine.

The filling and emptying of the container 5 up to the predetermined rinsing water quantity for the rinsing container 2 takes place by way of the program control apparatus of the machine and an outflow control device associated with the chamber 15. The outflow control device comprises a float 17 disposed on a rocker 29 in the chamber 15 and a switch 18, actuated by the rocker in the case of a determined float state or rocker position, for the closing of the inlet valve 6. For this purpose the outflow end of the downward duct 36 of the siphon 13 is directed from the container 5 to the chamber 15 onto the upper side of the rocker arm opposite to the rocker arm at which the float 17 is arranged. In an advantageous construction, the double-armed rocker 29 is centrally suspended from a cover of the chamber 15 and the arm associated with the outflow end of the siphon duct 36 forms a bowl 38 with a base opening 14, while the arm disposed opposite the rocker fulcrum 39 has the float 17 and carries a switch element 40 for actuation of the switch 18 seated on the cover.

Further integrated in the unit 24, near the throughflow chamb.er 15 arranged at the base side below the container 5, is a level regulating vessel consisting of an air lock chamber 25 which is linked to a pressure element, adjusted to a safety level 26, of the safety valve 6 and disposed in flow connection with the throughflow chamber 15 and with the sump 16 by way of a siphon 28 having an overflow sill 27.

1 - 8 Moreover, the filling container 5 has a ventilation dome 37 communicating with the ventilation channel 20. Due to the small crosssection of the ventilation dome 37, the water column quickly climbs therein on filling of the machine and enhances the coming into effect of the 5 siphon 13.

If the program control apparatus, actuated by a control motor, of the machine reaches a program section (pre-rinse, clean, intermediate rinse or clear rinse) with water requirement, the control apparatus is driven into a provided switching step for the filling of the rinsing container with a determined rinsing water quantity. Associated with this switching step is a level stop in such a manner that, during filling of the container 5, the program control apparatus stands still.

At the beginning of this switching step the inlet valve 6 is opened and the control apparatus motor switched off. Fresh water flows in from the water supply through the fresh water duct 9 of the unit 24. The main water jet passes the free flow path 7, flows-through the ion exchanger 4 and passes by way of the connection duct 19 into the container 5. The filling of the container 5 is complete after exceeding of the overflow sill 14 of the siphon 13, so that the siphon 13 is then effective. The water flowing out of the siphon downward duct 36 fills the bowl 38 and, due to the weight acting on the rocker 29, the switch 18 is actuated by the switch element 40, whereby the inlet valve 16 is closed and the control apparatus motor again lies at voltage. While the container 5 empties by way of the siphon 13 and through the throughflow chamber 15 into the outflow sump 16 of the rinsing container 2, the control apparatus motor runs during this 9 defined time section for, for example, 25 seconds.

When the container 5 is empty, the bowl 38 also runs empty by virtue of its opening 41, the float 17 can lower as a result of the reducing water level in the chamber 15 and the return pivot movement of the rocker 29 allows return switching of the switch 18 of the outflow control device. Thereby, the inlet valve 6 is again opened and the control apparatus motor again switched off. There follows a second filling and thereafter a second emptying process. Thereafter, the container 5 can be filled, for example a third time. If for that purpose after the filling of the container 5 with the third water quantity the inlet valve is closed and the control apparatus motor again switched on, approximately 50 seconds will have elapsed from a programmed time step of, for example, 60 seconds through two emptying times according to the given example. On emptying of the third water quantity, the predetermined total emptying time of 60 seconds can henceforth be exceeded, wherein the control apparatus motor moves on from the level stop after 10 seconds of the running emptying-time of the program control apparatus and into the following switching step, for example for the switching on of heating means, the pump or the like. As the chamber 15 forms a communicating pipe to the outflow sump of the rinsing container, the normal level sets in at the same time in the two spaces, so that the water state established in the throughflow chamber 15 holds the float inthelifted-up position. Through variation of the container 5, the cross-section of the siphon 13 or the outflow time in the described switching step, the rinsing water quantity can be changed. Merely a timer step of the program control apparatus is required for the entire filling control. The - 10 described filling and outflow control therefore manages with little control complication.

In the program sections preceding the regeneration of the ion exchanger, the store 8 is also filled with water. Superfluous water can flow out from the store 8 through the ventilation channel 20, the dome 37 to the filling container 5 and/or through the channel 21 and the inflow shaft 22 into the rinsing container 2. If the switch 45 is set to the highest water hardness, the connections 43 and 44 are tightly closed and the entire store volume is used for the brine preparation. If either or both of the connections 43 and 44 is or are opened, the associated siphon is ineffective and for the introduction of brine from the salt reservoir container 3 into the ion exchanger 4 there can be used only a part of the store volume. Thereafter, adjustment of the required regeneration quantity takes place at the switch 45. Depending on the local water hardness, the regeneration quantity and thus the brine quantity can be adjusted. After opening of a regenerating valve 47 the regenerating water flows into the salt reservoir container 3 and brings a corresponding brine quantity into the ion exchanger, from where it can be conveyed by way of the container 5 to the pump pot. On subsequent back-rinsing of the ion exchanger, water flows by way of the inlet valve 6, by way of the free flow path 7 and throughtheion exchanger 4 into the filling container 5. After filling of the container 5, this is automatically emptied by the siphon 13 into the pump pot 16.

If at the installation location of the dishwashing machine the water feed is small so that on reaching of the overflow sill 14 the inflowing water overflows by way of the curve of the siphon 13 without t 7 -t - 11 the siphon becoming effective, then with stationary control apparatus motor, however, the required rinsing water quantity can be fed to the rinsing container. For that purpose the water inflowing through the throughflow chamber 15 to the rinsing container 2 collects until it reaches the normal level in the communicating throughflow chamber. The float 17 then rises up so far that the switch 18 is actuated for the closing of the inlet valve 6 and for switching on of the control apparatus motor.

If the normal level of the rinsing container should be exceeded, the level regulating vessel 25 to 28 is effective. If the safety level 26 is reached, water runs through the small siphon 28 over the overflow sill 27 into the air lock chamber. Due to the pressure increase, a pressure element, connected to the air lock chamber, of the safety inlet valve 6 can stop the water supply to the machine.

Optionally, also, the emptying pump of the machine can be switched on.

Claims

1. A household appliance controllable by a program with a plurality of sections requiring operation of the appliance with water, the appliance comprising a rinsing container, water softening means com- prising a salt reservoir and an ion exchanger, a water storage chamber disposed above the water softening means and connected at an outlet thereof to an inlet of the salt reservoir, a flat filling chamber arranged between the rinsing container and a wall of the appliance and connected at an inlet thereof to an outlet of the ion exchanger, a throughflow chamber connected at an inlet thereof by way of a siphon to an outlet of the filling chamber and at an outlet thereof to the rinsing container, fresh water feed means comprising an inlet valve and a feed duct which is connected to an inlet of the ion exchanger and which includes a free flow portion disposed to permit filling of the storage chamber, and control means responsive to water state in the throughflow chamber to so control opening and closing of the inlet val ve as to permit supply to the rinsing container of the total volume of water, equal to a multiple of the volume of the filling chamber, required for operation of the appliance in one such program section, the inlet valve thereafter being controlled to emain closed until the next such program section.

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2. An appliance as claimed in claim 1, wherein the water storage chamber, the filling chamber, the throughflow chamber and the siphon are combined, together with part of the feed duct, a duct connecting the outlet of the storage chamber to the inlet of the salt reservoir, a duct connecting the outlet of the ion exchanger to the inlet of the 1 7 1 - 13 filling chamber, a ventilation duct for the free flow portion of the feed duct and a condensation and deaeration duct with inflow passage for the rinsing container, into an ass-embly unit.

3. An appliance as claimed in claim 2, wherein the unit is made 5 of plastics material.

4. An appliance as claimed in either claim 2 or claim 3, wherein the throughflow chamber is arranged under the base of the filling chamber and the appliance comprises level regulating means included in the unit and disposed adjacent to the throughflow chamber, the level regulating means comprising an air lock chamber connected by way of a siphon with the throughflow chamber or the rinsing container and operatively coupled to pressure-responsive means for controlling water flow into the appliance.

5. An appliance as claimed in any one of the preceding claims, said control means comprising a float disposed in the throughflow chamber and carried by a rocker, and a switch operable by the rocker to cause actuating means to actuate the inlet valve.

6. An appliance as claimed in claim 5, wherein an outflow end of the siphon in the connection between the throughflow chamber and the filling chamber is arranged to direct issuing water onto an upper side of a first arm of the rocker opposite to a second arm thereof carrying the float.

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7. An appliance as claimed in claim 6, wherein the first arm of the rocker defines a bowl provided in its base with an opening and the second arm of the rocker defines the float and an operating member to operate the switch, the rocker being pivotably mounted on a cover 5 of the throughflow chamber.

8. An appliance as claimed in any one of the preceding claims, comprising an electromechanical program control device and a drive to drive the control device, the inlet valve and the drive means being so controlled that during filling of the filling chamber the inlet valve is open and the drive is inoperative, during emptying of the filling chamber the inlet valve is closed and the drive operative, and after termination of the filling of the filling chamber with the final volume to complete said total volume the drive is operative to drive the control device for advancing of the program.

9. An appliance as claimed in any one of claims 2 to 4, wherein the storage chamber is arranged in the upper region of the unit to be disposed above the filling chamber and under both the free flow portion of the feed duct and the ventilation duct for that porti6n, and is provided with an overflow edge permitting flow into the rinsing container by way of the ventilation duct, the condensation and deaeration duct and the inflow passage and with a siphon selectably controllable to permit outflow of different water volumes from the storage chamber into the salt reservoir.

10. An appliance as claimed in any one of claims 2 to 4 and 9, wherein i n - 15 the condensation and deaeration duct includes a siphon forming a water condenser for steam from the rinsing container.

11. An appliance as claimed in any one of claims 2 to 4, 9 and 10, wherein the filling chamber is provided with a ventilating passage connected to the ventilation duct.

12. A household appliance substantially as hereinbefore described with reference to the accompanying drawing.

Y Pptent 04,ice.SW.. House 6671 IjiGh Yolcc:.r..Londc)n WC1r.. 4TP r=.er cc; ies maybe obtamedfrcn The Paten, Office.