GB2284980A

GB2284980A - Water filtering in a dishwashing machine

Info

Publication number: GB2284980A
Application number: GB9425452A
Authority: GB
Inventors: Johann Wilhelmstaetter; Rudiger Eiermann; Herbert Gunzl; Helmut Jerg; Roland Rieger
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-12-23
Filing date: 1994-12-16
Publication date: 1995-06-28
Anticipated expiration: 2014-12-16
Also published as: ITMI940829V0; FR2714282B1; DE4344245C2; ITMI940829U1; IT234291Y1; DE4344245A1; FR2714282A1; TR28076A; GB2284980B; GB9425452D0

Description

WATER FILTERING IN A DISHWASHING MACHINE The present invention relates to

a dishwashing machine and has particular reference to water filtering and outlet means in such a machine.

Dishwashing machines are provided with a coarse filter which serves to protect a pump against coarse particles liable to cause clogging or damage of the pump, but which allows contamination particles to pass that are not likely to lead to such clogging or damage. The coarse filter also serves to prevent deposits of unused cleaning agent on the base of an outlet trough of the machine.

Water filtering and outlet arrangements are known from DE-OS 31 14 663 and the DE-PS 34 26 661, in which the coarse filter sieve is pot shaped. It has proved in practice that not only coarse particles, which can lead to clogging or damage of the pump, but also large area substances, such as milk skins and so forth, are retained by such filters, which results in clogging of the filter and thus reduces the rinsing performance of the dishwashing machine.

There is thus a need for water filtering and outlet means for a dishwashing machine, by which associated pumps may be protected against coarse particles which lead to clogging or damage of the pumps, but which allows particles to pass that do not lead to such clogging or damage. At the same time deposits of unused cleaning agent should be avoided, and clogging of the filtering arrangement should be avoided in simple mode and manner.

According to the present invention there is provided equipment at a dishwashing machine for filtering rinsing water, with an outlet sump which is provided at a base trough of a rinsing container of the machine and has connecting stub pipes for a circulating pump and an emptying pump, a filter comprising a funnel-shaped fine filter of large area which passes over into a fine sieve cylinder which in the outlet sump bounds an outlet channel leading to the connecting stub pipe of the emptying pump, and a coarse filter which is arranged in the outlet channel and bounds a flow channel from the rinsing container to the circulating pump or the emptying pump, the coarse filter having substantially the shape of a tube open at both ends and with a closed casing and means for flow deflection being arranged in the coarse filter.

Through the use of a coarse filter without filter base, but with flow-deflecting means, a filtering arrangement is achieved in which pumps connected to the outlet stub pipes are protected bythe flow deflecting means against coarse particles which could cause clogging or damage of the pumps, since these coarse particles, for example toothpicks, bones and so forth, are caught at the flow deflecting means. However, particles which do not lead to clogging or damage of the pumps, and also large area contaminants such as milk skins and so forth, can pass the flow deflecting means, whereby clogging of the coarse filter is prevented in simple mode and manner, namely by allowing passage large area contaminants.

Morever, deposits of unused cleaning agent on the sump or outlet trough base are avoided due to the movement, which is produced by the flow deflecting means, of the throughflowing ringing liquid.

In a preferred feature, the means for flow deflection comprise transverse webs, which are arranged at a spacing from each other and substantially transversely to the flow direction and which project into the coarse filter from opposite sides thereof and partially overlap. By means of a labyrinth arrangement of that kind, a simplification of construction may be achieved.

For preference, at least two transverse webs are arranged in the coarse filter. This measure serves for further simplification.

In one advantageous embodiment, the transverse webs are arranged to be inclined in flow direction, whereby a better passing of contaminants of large area is achieved and a washing-back of coarse dirt particles deposited underneath the coarse filter is prevented.

Thickened portions can be arranged at the free ends of the webs to avoid the risk of injury to the user during cleaning of the coarse filter and to enable deposition of cleaning agent, which can dissolve therein since it is exposed to the liquid flow.

A simpler construction of the coarse filter can be achieved in particularly advantageous manner if the web, which is first in direction of flow, is formed as continuation of a bearing rim of the coarse filter.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawing, the single figure of which is a sectional view of the region of a base trough in a dishwashing machine embodying the invention.

4 Referring now to the drawing there is shown an outlet trough or sump 2, which has a connecting nipple 3 for a circulating pump (not shown) and a connecting nipple 4 for an emptying pump (not shown) and which is provided at a base trough 1 of a rinsing container of a dishwashing machine. The machine is provided with equipment for filtering of rinsing water, in particular a funnel shaped fine sieve 5 of large area, which passes over into a fine sieve cylinder 6 which in the sump 2 bounds an outlet channel 7 leading to the connecting nipple 4 of the emptying pump, and a coarse sieve 10, which is arranged in the channel 7 and which is inserted into a receptacle equipment 17, equipped with a handle 18.

The sieve 10 is supported on the receptacle 17 by way of a bearing rim 16 and is removably mounted by means of the receptacle 17 at the transition between the sieves 5 and 6. In the illustrated embodiment, the fine sieve cylinder 6 is surrounded by an even finer sieve cylinder 8. The flow direction of rinsing liquid through the coarse sieve 10 is indicated by a solid arrow 20. The flow direction to the circulating pump and to the emptying pump is illustrated by dashed arrows 23 and 24.

In the illustrated embodiment, projections 9 for the retention of solid foreign bodies that have possibly reached the connecting nipple 4 are arranged in this nipple.

The coarse sieve 10 has substantially the form of a tube open at both ends and with a closed wall. Arranged in the sieve 10 are means for flow deflection, in particular a plurality - two in the present embodiment - of transverse webs 11 and 12 extending substantially transversely to the direction of flow. The webs 11 and 12, which are arranged at a spacing from each other, project into the sieve 10 from opposite sides thereof and partially overlap.

The webs are arranged to be inclined in the flow direction 20 and have thickened portions 15 at their free ends 13 and 14. The web 11, which is first in flow direction 20, is formed as a continuation of the bearing rim 16 of the sieve 10.

Through the use of the coarse sieve 10 without a base, but with the afore-described flow deflecting means constituting a labyrinth, the filtering of the rinsing water is such that the pumps are protected against coarse articles which may lead to clogging or damage of the pumps, for example toothpicks, bones and so forth, as these are left hanging in the flow deflecting means. However, dirt particles which do not lead to clogging or damage of the pumps, for example large area residues such as milk skins and so forth, can pass through the coarse sieve, whereby a clogging of the sieve by such residues is prevented. A large proportion of the coarse dirt particles is then removed from the dishwashing machine by way of the emptying pump and contamination of crockery in the dishwashing machine by coarse dirt left in the sieves from a preceding program section is avoided. Deposits of unused cleaning agent on the sump base are avoided due to the movement, which is produced by the flow deflecting means, of the throughflowing rinsing liquid and by deposition of cleaning agent on the webs 11 and 12, where it is exposed to the liquid flow and can dissolve. A risk of injury to the user during the cleaning of the sieve 10 is avoided by the thickened portions 15 at the free ends 13 and 14 of the webs.

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Claims

1. A dishwashing machine provided at the base of a rinsing chamber thereof with water filtering and outlet means comprising a sump with a dischargewater outlet and a circulation water outlet, a fine filter having a substantially funnel-shaped portion and a substantially cylindrical portion which is connected thereto and defines an outlet channel leading to the discharge water outlet, and a coarse filter arranged in the outlet channel and bounding a flow channel for water flowing from the chamber to the outlets, the coarse filter comprising a substantially tubular member open at both ends and with a closed wall, and flow deflecting means arranged in the member.

2. A dishwashing machine as claimed in claim 1, the flow deflecting means comprising a plurality of spaced apart transverse webs which project from opposite sides of the member substantially transversely with respect to the direction of flow through the flow channel from the chamber towards the outlets and partially overlap in that direction.

3. A dishwashing machine as claimed in claim 1, the deflecting means comprising at least two webs arranged to extend substantially transversely with respect to the direction of flow through the flow channel from the chamber towards the outlets.

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4. A dishwashing machine as claimed in claim 2 or claim 3, wherein the webs are inclined in said direction.

5. A dishwashing machine as claimed in any one of claims 2 to 4, wherein each of the webs has a thickened portion at a free end 5 thereof.

6. A dishwashing machine as claimed in any one of claims 2 to 5, wherein the or an upstream one of the webs is formed as a continuation of an upper end support rim of the member.

7. A dishwashing machine as claimed in any one of the preceding claims, comprising a respective pump connected to each of the outlets.

8. A dishwashing machine substantially as hereinbefore described with reference to the accompanying drawing.