GB2144031A

GB2144031A - Dishwashing machine

Info

Publication number: GB2144031A
Application number: GB08411394A
Authority: GB
Inventors: Ernst Stickel; Helmut Jerg
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-07-27
Filing date: 1984-05-03
Publication date: 1985-02-27
Also published as: FR2549710A1; DE3327098C2; GB2144031B; IT1176422B; FR2549710B1; GB8411394D0; IT8421942A1; DE3327098A1; IT8421942A0

Abstract

In a dishwashing machine comprising a level regulating vessel (21), which is connected through a duct (25) with an outflow sump (2) of a rinsing container (1) of the machine, a valve (27, 28, 29), is arranged to prevent flow through the duct in the direction from sump to level regulating vessel. <IMAGE>

Description

SPECIFICATION Dishwashing machine The present invention relates to a dishwashing machine.

In a dishwashing machine described in DE AS 25 45 037, dirt particles entrained by the rinsing liquid can pass into a level regulated vessel of the machine and be deposited there, which after a longer period of operation of the machine leads to blockage of the channels of the level regulating vessel. In order to avoid this, it has been proposed to switch on an emptying pump of the machine before switching off a circulating pump of the machine. In addition, a water feed vessel was so arranged in front of the level regulating vessel that during filling by fresh or soft water, a current through the level regulating vessel was induced and, as the rinsing container filling level rose, was directed to preclude dirty water from the rinsing container outflow trough reaching the level regulating vessel.

Nevertheless, after completion of the filling operation and during the operation of the circulating pump, there is a risk that dirty water rises up into the level regulating vessel and after some time impairs its function.

In order, in the case of such a dishwashing machine with level regulating equipment, to be able to regularly clean an air trap chamber, which is prone to clogging and to which level switches are connected, it is known from DE OS 29 07 269 to provide a valve which is controllable with the emptying pump and which is disposed in the base of an overflow partition arranged in front of the air trap chamber. Since the food remnants, which have been deposited in the air trap chamber, cannot flow on their own out of the chamber even when the valve in the overflow partition is opened, clogging of the level regulating vessel is not prevented.

There is thus scope for improvement in the measures for protecting a level regulating vessel of a dishwashing machine against the entry of dirty water.

According to the present invention there is provided a dishwashing machine comprising a rinsing chamber with an outflow sump emptiable by pump means, a level regulating chamber connected to the sump by way of duct means and to fresh water feed means, and valve means arranged to prevent flow through the duct means in direction from the sump to the level regulating chamber.

By means of the valve means arranged in front of the level regulating chamber on the dirty water side, a return flow barrier may be created to protect the chamber against inflow of dirty water.

Embodiments of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Figure 1 is a schematic working diagram of a first dishwashing machine embodying the invention; Figure 2 is a sectional view of a valve arranged in an outflow trough of the machine of Fig. 1; Figure 3 is a plan view of the valve of Fig.

2; Figure 4 is a sectional view of a modified form of the valve; Figure 5 is a schematic working diagram of a second dishwashing machine embodying the invention; Figure 6 is a sectional view of a valve arranged in an outflow sump of the machine of Fig. 5; and Figure 7 is a plan view of the valve of Fig.

6.

Referring now to the drawings, there is shown in Fig. 1 part of a dishwashing machine which comprises an outflow trough or sump 2, to which an emptying pump and a circulating pump (not shown) are connected, arranged in the base of a rinsing container 1, softening equipment consisting of a salt container 3 and an ion exchanger 4, and a storage container 5 which is disposed above the softening equipment and preferably arranged at a side wall of the rinsing container.

An outflow duct 6 leads from the base of the storage container to the salt container. The dishwashing machine is connected through an electromagnetic inlet valve 7 to a water feed duct 8. From the inlet valve 7, a fresh water duct 9 leads by way of a free flow path 10 in the storage container 5 to the ion exchanger 4, from which a fresh water feed duct 11 branches off to the outflow trough 2. The storage container 5, which can be filled up to an overflow level by means of leakage water from the free flow path, can be of the type more closely described in DE-PS 31 44 866.

A duct 13 leads from an overflow 12 of the storage container 5 into the rinsing container.

In the case of the illustrated embodiment, the salt container 3 has a closable filling stub 14 and an aeration duct 15, and a regenerating valve 17 is disposed in a connecting duct 16 to the ion exchanger 4. The ion exchanger delivers softened water by way of a soft water duct 18 into the outflow trough 2.

A level regulating vessel 21, such as that more closely described in DE-GM 82 18 877, is associated with the rinsing container 1 for the monitoring of a normal level 19 and a safety level 20. In that case, a safety level transmitter of the vessel 21 is connected by a control line 22 with a safety valve 23, which is arranged downstream of the inlet valve 7.

The valve 7 is opened in dependence on the program and is closable by a switch 30 of the level regulating equipment.

The outflow trough 2 has an upper stub pipe 24 connected with the fresh water feed duct 11 and a lower stub pipe 26 connected by way of an emptying duct 25 with an opening in the base of the vessel 21. Associated with the pipes 24 and 26 is a valve body 29, which is disposed in a valve housing 27, 28 and acts as a flow barrier to protect the level regulating vessel 21 against the ingress of dirty water from the outflow trough, the valve body being provided at the inside wall of the trough 2.

As shown in Fig. 2, the valve formed by the body 29 and housing consists of an upper housing part 27, a lower housing part 28, a diaphragm 31 tightly clamped therebetween and a float 29 fastened thereto. The upper and lower housing parts are tightly detented, with the interposition of the diaphragm 31, by retaining lugs 32. The valve housing formed thereby is plugged from the interior space of the outflow trough into the pipes 24 and 26 moulded onto the outflow trough 2 and detented through at least one detent lug 33 or the like. The diaphragm 31 has a bypass opening 34. The float 29 carries a valve plate 35, which is raised when the outflow trough is filled and closes off a valve opening 36 in the lower housing part 28 from the outflow trough. The valve seat of the valve opening is designated by 37.

When the rinsing container is empty, the valve is slightly opened due to the position of the diaphragm 31 and the float 29. Thus, the vessel 21 can empty itself by way of the duct 25 into the trough 2. If rinsing liquid is supplied to the rinsing container 1 or to the trough 2 for a new rinsing operation, then the float 29 rises and closes the valve opening 36 before the liquid can get into the valve housing 27, 28. On the other hand, a pressure acts during the filling operation on the diaphragm 31, due to the connection of the upper housing chamber with the fresh water feed duct 11, so that the diaphragm presses the float 29 downwardly. As a result, a communicating connection is maintained between the vessel 21 by way of the duct 25, the pipe 26 and the valve opening 36 to the trough 2.

At this time, the ingress of dirty water into the lower valve housing chamber is prevented by the fresh water current from the duct 11 by way of the pipe 24, the bypass opening 34 and the valve opening 36 to the trough 2. At the same time, however, fresh water can pass from the lower valve housing chamber into the vessel 21 for the level regulating equipment to become effective. On attainment of the filling level, the level regulating equipment closes the inlet valve 7 or the safety valve 23.

As a result, the pressure in the upper valve housing chamber decays by way of the bypass opening 34, and the buoyancy of the float 29 causes it to close the valve opening 36. Thus, the connection from the trough 2 to the vessel 21 is made only when the rinsing container is empty and in the filling operation, and ingress of dirt into the vessel 21 is not possible.

In the construction according to Fig. 4, the buoyancy of the float 29 in enhanced by a spring 38. When the rinsing container is empty, the return flow barrier formed by the valve is effective. The emptying of the vessel 21 takes place either by way of leakage of the system, but at the latest during the filling operation.

The embodiment according to Fig. 5 largely corresponds to the dishwashing machine described in connection with Fig. 1. In that case, however, the upper stub pipe 24 is connected to the soft water duct 18, by way of which clean softened water is fed from the ion exchanger 4 to the rinsing container 1 or to the trough 2.

According to the Figs. 6 and 7, the valve associated with the pipes 24 and 26 comprises a valve housing 41, which is insertable into guides 39 at the inside wall 40 of the trough 2 and defines a prolongation pipe 42 for the upper pipe 24 and a vertical guide cylinder 43 for the float 29. The guide cylinder communicates at its upper end through a first valve opening 44 with the pipe 42, at its lower end through a second valve opening 45 with the trough 2, and in the region of its wall through a third opening 46 with the lower pipe 26, which as before is connected to the level regulating vessel 21. The housing 41 is insertable from above into the guides 39.

When the rinsing container is empty, the valve is opened by reason of the weight of the float 29 so that the vessel 21 can empty.

With the rinsing container filled, the float is raised by the water level in the trough and closes the two valve openings 44 and 45.

During the filling operation, the float 29 is pressed downwardly by the flow pressure and by increased static pressure due to an enlarged region 47 of the pipe 42. As a result, on the one hand a communicating connection is maintained between the trough 2 and the vessel 21 by way of the second valve opening 45 until the level regulating equipment responds, while on the other hand soft water flowing in through the pipe 24 from the ion exchanger 4 flows through the first and second valve openings 44 and 45 to the outflow trough and prevents a pollution of the vessel 21 and also of the valve. At the same time, a flow of the water passes through the third opening 46 to the vessel 21. After the closing of the inlet valve 7 or the safety valve 23, the buoyancy of the float 29 causes both valve openings 44 and 45 to be closed.

Claims

1. A dishwashing machine comprising a rinsing chamber with an outflow sump emptiable by pump means, a level regulating cham ber connected to the sump by way of duct means and to fresh water feed means, and valve means arranged to prevent flow through the duct means in direction from the sump to the level regulating chamber.

2. A dishwashing machine as claimed in claim 1, the valve means comprising a movable valve element in the form of one of a float, a ball and a poppet.

3. A dishwashing machine as claimed in either claim 1 or claim 2, wherein the sump is provided with an upper duct portion connected to the fresh water feed means and with a lower duct portion connected by way of said duct means to an opening at the base of the level regulating chamber, the valve means comprising a valve housing with a valve opening communicating with the sump, and a movable valve element co-operable with a valve seat at the valve opening to control flow between the duct portions and the sump.

4. A dishwashing machine as claimed in claim 3, wherein the valve housing is mounted at wall means of the sump and comprises an upper housing portion and a lower housing portion connected to the upper housing portion, and the valve element comprises a diaphragm, which is arranged between the housing portions to separate the upper duct portion from the lower duct portion and which is provided with a bypass opening, and a float which is connected to the diaphragm and which is arranged to close the valve opening when the water in the rinsing chamber is above a predetermined level and to open the valve opening, under fresh water flow pressure acting on the diaphragm by way of the upper duct portion, to permit flow through the bypass opening and valve opening to the sump and through the bypass opening, lower duct portion and duct means to the level regulating chamber.

5. A dishwashing machine as claimed in claim 4, wherein the float is arranged to additionally open the valve opening during emptying of the sump so as to permit flow from the level regulating chamber into the sump.

6. A dishwashing machine as claimed in claim 4, the valve means further comprising spring means acting between the float and the housing to cause the valve opening to be closed by the float during emptying of the sump.

7. A dishwashing machine as claimed in either claim 1 or claim 2, wherein the sump is provided with an upper duct portion connected to an outlet of the ion exchange means of water softening equipment of the machine and with a lower duct portion connected by way of said duct means to an opening at the base of the level regulating chamber, the valve means comprising a housing with a valve opening communicating with the sump, and a movable valve element co-operable with a valve seat at the valve opening to control flow between the duct portions and the sump.

8. A dishwashing machine as claimed in claim 7, wherein the valve housing is mounted at wall means of the sump and comprises a pipe communicating with the upper duct portion and with the sump and a guide bore connected at an upper one of its ends with the pipe by way of a first opening, at its lower end with the sump by way of a second opening and intermediate its ends with the lower duct portion by way of a third opening, and the valve element comprises a float slidably guided in the guide bore and arranged to close the first and second openings when the water in the rinsing chamber is above a predetermined level, to open the second and third openings during emptying of the sump, and to open the first, second and third openings, under softened water flow pressure acting on an upper end of the float by way of the upper duct portion and the pipe, to permit flow through the first opening, the bore and the second opening to the sump and through the first opening, the bore, the third opening, the lower duct portion and the duct means to the level regulating chamber.

9. A dishwashing machine as claimed in claim 8, wherein the flow cross-section of the pipe is greater in the region of the first opening than that of the upper duct portion.

10. A dishwashing machine substantially as hereinbefore described with reference to Figs. 1 to 3 of the accompanying drawings.

11. A dishwashing machine substantially as hereinbefore described with reference to Figs. 1 and 4 of the accompanying drawings.

12. A dishwashing machine substantially as hereinbefore described with reference to Figs. 5 to 7 of the accompanying drawings.