GB2133975A

GB2133975A - Water softening equipment for a dishwashing machine

Info

Publication number: GB2133975A
Application number: GB08400766A
Authority: GB
Inventors: Manfred Seessle; Ernst Stickel; Anton Oppel; Konrad Klein; Lothat Kleinle; Manfred Strobel; Laszlo Szabo
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-01-26
Filing date: 1984-01-12
Publication date: 1984-08-08
Also published as: FR2542602A1; IT8419301A0; DE3302566A1; DE3302566C2; GB8400766D0; FR2542602B1; IT1173127B; GB2133975B

Abstract

Water softening equipment for a dishwashing machine is settable to local water hardness and comprises a water hardness switch (19) through which a ventilating duct (18), which is connected with a two chamber water reserve container (2), is openable or closable. At the same time, in dependence on the selected switch setting, an indicating device monitoring the filling level of a salt reserve container (4) is switchable on or off. <IMAGE>

Description

SPECIFICATION Water softening equipment for a dishwashing machine The present invention relates to water softening equipment for a dishwashing machine.

A dishwashing machine with water softening equipment is disclosed in DE-OS 28 53 773. A water reserve container used in this equipment consists of two chambers, one of which is supplied directly with water and is connected through an outlet duct with a salt container. The other chamber, which is only downwardly open, is connected with the first chamber in liquidconducting manner. The second chamber is also provided with a ventilation valve in its upper region.It is therefore possible in this known equipment to dimension the quantity of brine to be conducted out of the salt container to the ion exchange container for the regeneration of its filling in that either with the valve closed only the water reserve of the first chamber or with the valve opened additionally the water contained in the second chamber is conducted out of the water reserve container to the salt container. The volume of the first chamber of the water reserve container is so designed that it suffices after each machine program run-down for the regeneration of the ion exchange filling of almost all types of household dishwashing machine used in central Europe.Only in the case of the low number of machines used in areas of extreme water hardness is it necessary to conduct a quantity of brine corresponding to the metering volume of both the chambers of the water reserve container to the ion exchange container for regeneration. In the case of the overwhelming number of machines in areas with normal water hardnesses, there is a risk that if the valve becomes leaky, the second chamber of the water reserve container is likewise filled with water and brine is therefore metered excessively.

This is undesired for economic reasons as well as for reasons of environmental protection.

In order not to increase, but rather to reduce the brine consumption in a water softening equipment of this kind when the metering equipment in the water reserve container becomes ineffective, it is proposed in DE-PS 31 44 866 that the water reserve container has at least two chambers which are connected together through a respective ventilatable siphon. The two chambers of the water reserve container lie one beside the other and have a common separating wall, over which the siphon elbow extends, to which is connected a ventilating duct which is led to the front side of the machine and at its free end has a valve or the like.If the water reserve container is provided with further chambers which in turn are connected together through a respective ventilatable siphon, then the required quantity of brine can be set in several steps through ventilation of these siphons. If the valve of the ventilating duct should start to leak in hard water areas, the ion exchanger is regenerated in every case with a quantity of brine, albeit small.

It would thus be desirable to provide water softening equipment by means of which the setting to local water hardness and the switching of associated indicating means is possible with simple construction at an accessible place of the dishwashing machine.

According to the present invention there is provided water softening equipment for a dishwashing machine, the equipment comprising a water container with two interconnected chambers, a salt container connected to an outlet of one of the chambers, electrically controllable indicating means for monitoring the filling level of the salt container, a ventilating duct connected at one end thereof to the water container, and a control switch connected to the ventilating duct at the other end thereof and comprising a housing, a valve element arranged in the housing and actuable to selectively open and close the ventilation duct, and contact means operable by the valve element and disposed in an electrical circuit of the indicating means.

In advantageous manner, the control switch can be separated from the water container by way of a hose and can be mounted at a desired place in the door, an operating panel or at another part of the machine housing. At the same time, in accordance with the switch setting, the water softening equipment can be set to the local water hardness and an electrical salt indication switched on or off.

In soft water areas, where the dishwashing machine can be operated with satisfactory rinsing result without use of the water softening equipment, a first switch setting can be selected in which the indicating means monitoring filling-up of the salt container is switched off. In this switch setting, the ventilating duct to the water container can be opened - in a construction in which the chambers are connected by a ventilatable siphon - so that the volume of one chamber can flow out of the water container to an ion exchange container in a programmed regenerating cycle.

However, as the not replenished salt container is in this case filled only with water, the already soft local water can be supplied without further softening through the ion exchanger into the machine rinsing container.

In areas of normal water hardness, a second setting of the switch can be selected. In this setting, the indicating means can be switched on and the ventilation duct to the water container opened, so that the brine preparation takes place with the water volume of one chamber.

In areas of great water hardness, the ventilating duct can be closed in a third switch setting so that the siphon can become effective during emptying of the water container. Emptying of both chambers therefore takes place on initiation of the regeneration process. The water stored in the two chambers now pushes a great quantity of brine out of the salt container. The indicating means can also be switched on in this third switch setting.

In modification, it is possible to so arrange the coincident of the ventilating bores of the switch with the ventilating duct opening that the chambers, in the case of a water container according to DE-OS 28 53 773 or a corresponding water container according to DE-GM 80 29 987, are ventilated only when the dishwashing machine is set up in an area of high water hardness.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a schematic sectional elevation of a dishwashing machine with water softening equipment embodying the present invention; Fig. 2 is a rear view of a control switch in the equipment of Fig. 1; Fig. 3 is a side elevation of the switch of Fig. 2; Fig. 4 is a partially sectioned plan view of the switch; and Fig. 5 is a longitudinal sectional view of the switch.

Referring now to the drawings, there is shown a dishwashing machine comprising a rinsing container 1, against which a water reserve container 2, which is constructed as flat blowmoulded part of plastics material can be so placed that the container 2 is disposed above an ion exchanger 3 and a salt reserve container 4. A freshwater feed duct 5, in which a water inlet valve controlled by a program control device (not shown) of the machine is arranged, opens in a nozzle 6 of the container 2. Arranged downstream of the nozzle 6 and separated by a free flow path 7 is a diffuser 8. Connected to the diffuser 8 is a duct 9 which is blockable by a raw water valve and which leads to the ion exchanger 3. The ion exchanger 3 is connected through an outlet pipe with the rinsing container 1.

The water reserve container 2 in the illustrated embodiment has two upwardly open chambers 10 and 11 disposed one beside the other. In addition, the container 2 is provided with an overflow shaft 13, which is separated by a wall 12 from the chamber 11 and opens into the rinsing container.

The chambers 10 and 11 are separated each from the other by a separating wall 14 having a lesser height than the wall 12, which at its upper side forms an overflow threshold 17 to the shaft 12.

Passing over the wall 14 is a siphon 1 5, the two limbs of which extend close to the bottom of the chambers. The elbow 1 6 of the siphon 1 5 lies below the level predetermined by the overflow threshold 1 7 of the wall 12. Connected to the elbow 16 is a ventilating duct 18 of small crosssection leading to the front side of the dishwashing machine, where the duct is connected at its free end with a water hardness switch 19. From the bottom of the chamber 10, an outlet duct 20 leads into the salt reserve container 4 of the water softening equipment, which container is connected through a brine duct with the ion exchanger 3. The regeneration process is controlled through program-controlled valves (not illustrated). A ventilation channel for the rinsing container 1 is designated by 43.

The switch 19 comprises a housing 21, in which a disc-shaped setting element 23 is guided, the element 23 being rotatable through a switch shaft 22 provided with a key face 39 or carrying a rotary knob. Plugged onto the free end 24 of the duct 18-is a connecting stub pipe 25 of the housing 21 which in the illustrated embodiment is disposed in a panel above a door 30 of the dishwashing machine. A seal 32, which is nonrotatably arranged in a recess 38 of the setting element 23, is provided between the setting element and a housing plate carrying the stub pipe 25. The seal and the disc of the setting element have permanently coinciding bores 33 and 34, which for the ventilation of the siphon 1 5 can be brought into coincidence with the connecting stub bore 26.The setting element 23, which is rotatable through the switch shaft 22, is retained in the housing 21 through spring arms 37 and detent lugs 36. In that case, detents 40 are associated with the individual switch settings and the displacing range of the setting element is limited through an abutment 41 of the setting element and a protrusion 42 of the housing plate of the switch housing. A fastening plate of the switch housing is designated by 35.

The switch 19 is also connected by plug terminals 27 and 28 to the electrical current circuit of an indicating device monitoring the filling level of the salt reserve container 4. A resilient switch contact 29 is provided in the switch housing between fixed contacts 27' and 28' of the terminals 27 and 28. The switch contact 29 is fastened to the fixed contact 27' and is actuable for opening and closing of the current circuit through a cam track 31 of the setting element.

In a first switch setting to be selected in soft water areas, the setting element is so actuated that one of the bores 33 and 34 coincides with the bore 26 of the stub pipe 25 for the ventilation of the siphon 1 5 and the current circuit of the indicating device is in that case opened so that filling-up of the salt reserve container is not signalled.

In areas of normal water hardness, the siphon is also ventilated through coincidence of the other one of the bores 33 and 34 with the bore 26 in a second switch setting. Additionally, the current circuit of the indicating device is now closed so that a required filling-up of the salt reserve container is indicated.

In areas of great water hardness, the ventilating duct 18 is closed in a third switch setting so that both chambers 10 and 11 of the water reserve container 2 serve for brine preparation. The indicating device is also switched on in the third switch setting.

In a modification, conductor tracks connected with the current circuit of the indicating device are arranged in the switch housing 21 and wiping contacts are arranged at the setting element 23.

Claims

1. Water softening equipment for a dishwashing machine, the equipment comprising a water container with two interconnected chambers, a salt container connected to an outlet of one of the chambers, electrically controllable indicating means for monitoring the filling level of the salt container, a ventilating duct connected at one end thereof to the water container, and a control switch connected to the ventilating duct at the other end thereof and comprising a housing, a valve element arranged in the housing and actuable to selectively open and close the ventilation duct, and contact means operable by the valve element and disposed in an electrical circuit of the indicating means.

2. Equipment as claimed in claim 1 , wherein the housing comprises a stub pipe inserted into pipe means defining the duct, and the valve element is actuable to open and close the bore of the stub pipe.

3. Equipment as claimed in either claim 1 or claim 2, the contact means comprising a resilient member which is electrically connected to one of two terminals arranged in the housing and which is deflectable by cam means of the valve element to contact the other one of the terminals, the terminals being connected to the electrical circuit of the indicating means.

4. Equipment as claimed in either claim 1 or claim 2, the contact means comprising a contact disposed on the valve element and movable therewith to wipe conductor tracks arranged on the housing, the tracks being connected to the electrical circuit of the indicating means.

5. Equipment as claimed in any one of the preceding claims, wherein the valve element comprises a disc arranged in the housing to be rotatable about an axis by means of an actuating shaft, and a seal is arranged between the disc and a surface portion of the housing, said surface portion being provided at a spacing from the axis with an opening to the ventilation duct and the disc and the seal being provided with aligned bores selectably alignable with said opening through rotation of the disc.

6. Equipment as claimed in claim 5, wherein the housing is made of plastics material and is integrally provided with a mounting plate and with resilient detent means retaining and rotationally guiding the disc.

7. Equipment as claimed in either claim 5 or claim 6, wherein the seal is arranged in a recess in the disc to be rotatable with the disc.

8. Equipment as claimed in any one of claims 5 to 7, wherein the actuating shaft is provided with means to facilitate turning of the shaft for rotation of the disc.

9. Equipment as claimed in any one of claims 5 to 8, wherein the disc and the seal are provided respectively with two aligned first bores and with two aligned second bores and the disc is selectively settable in a first rotational setting in which the first bores are aligned with such opening and contacts of the contact means are opened, a second rotational setting in which the second bores are aligned with said opening and the contacts are closed, and a third rotational setting in which the opening is closed by the seal and the contacts are closed.

10. Equipment as claimed in claim 9, comprising detents to locate the disc in each of the first, second and third rotational settings and abutment means to limit rotation of the disc past each end one of the three settings.

11. Equipment as claimed in any one of the preceding claims, wherein the chambers are interconnected by a siphon and said one end of the ventilating duct is connected to the bend of the siphon.

12. Water softening equipment substantially as hereinbefore described with reference to the accompanying drawings.

13. A dishwashing machine provided with equipment as claimed in any one of the preceding claims.

14. A machine as claimed in claim 13, wherein the housing of the control switch of the equipment is mounted on one of a casing of the machine, a rinsing container of the machine, a door of the machine and a control panel of the machine.