EP0441756A1

EP0441756A1 - A self-cleaning filter for washing machines

Info

Publication number: EP0441756A1
Application number: EP91830026A
Authority: EP
Inventors: Luigi TajÀ©
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-02-02
Filing date: 1991-01-30
Publication date: 1991-08-14
Also published as: IT9047591A1; IT9047591A0; IT1239791B

Abstract

The device comprises a self-cleaning filtering element (3) that can be partially rotated so as to open a discharge opening (7) and to close the recirculating opening (4), while performing at the same time the counter-stream washing (with already filtered water) on one side of the filtering element (3).

Description

The present invention concerns a filter that, placed downstream of one single charging and discharging pump already known in dish washers and similar, always catches all the circulating waterfor obtaining an optimal washing of the dishes or similar, having only clean, i.e. filtered water, in circulation.
Infact, the filter according to the present invention is kept always clean as it is washed counter-stream and with already filtered (therefore clean) water, each time a water discharge takes place.
For obtaining the aim set forth, the filtering element is angularly displaced by an electromagnet controlled by the washing programme; the displacement is requested for closing the water passage from the washing whirlpool and, at the same time, opening the discharge that may however be reached by the water only after having passed through the filter washing it counter-stream.
A plurality of systems aiming at least to the partial realization of what described are already known, but the solution according to the present invention seems to be original under the functional and realizing aspect.
A dish washer realized according to the present invention comprises a filter with wide holes of the known kind for keeping, upstream of the pump, the great impurities or foreign bodies; furthermore the pump and the corresponding self-cleaning filter, forming the object of the present invention.
The present invention will be described more in detail hereinbelow according to the enclosed drawings, in which a preferred embodiment is shown.
Figures 1 and 2 show a scheme of the filter according to the present invention and the section A-A.
Figures 3 and 4 show a section according to line B-B of figure 1 of the filter according to the present invention, respectively placed in the water charging phase to the whirlpools and in the discharging phase.
Relating now to the details of the figures, the water coming from the only pump of the dish washer (charge and discharge) gets into duct 1 that, where required, may be out of one piece with the pump's outlet.
From said duct the water just touches, through chamber 2, the outside of filter 3 that has a parallelepiped shape, rounded at the ends, and on the frame whereof a small net it applied having the desired mesh. The water containing the residuals taken away from the dishes (or in the case of clean water, of soap clots) is filtered by the net surrounding the body 3 and, once the residuals or the soap not dissolved, enters in the body 3 passing under pressure through hole 4 connected to the washing whirlpools.
During this operation the soap that did not melt gets deposited on the small net and is further removed by the water that must pass through the filter.
Once the washing operation is completed, the timer that controls thepump for performing the discharge operated an electromagnet 10 that makes rotate the filter body, e.g., of 45°.
Said filter gets places so as to show to the dirty water only one side provided with the small net, through which the water passes depositing the residuals taken from the dishes; the filtered water is therefore clean and forced to wash counter-stream the other side of the filter from which it takes away the food residuals already placed on the small net and leads them to the discharge 7 which is made accessible due to the rotation of the filter body 3.
At the same time, and always due to above mentioned rotation of the filter body, the ends 5 or 6 being part of the cover 8 of filter 3 alternatively close the passage 4 of the water to the whirlpools.
The body 3 of the filter contains a helicoidal spring or any other suitable device which, when pushing on the cover 8, realizes a sealing closing on the internal (circular) surface of the frame 9 of the filter on which are provided the ducts 4 for charging to whirlpools and 7 for discharge.
In the following discharge, a second electromagnet 10 or any other control device moves the filter body 3 in the direction opposite to the precedentone, allowing the counter-stream washing with clean water of the other side of the filter.
A simple spring game, not shown in the figures, makes filter 3 placed centrally until one of the two electromagnets gets not excited for putting the filter into washing position.
For what concerns the functioning of the object according to the present invention, the water aspired from the recollection basin by means of the pump, before getting to the whirlpools (the lower and the upper one) passes through the filter and leaves inside the same all residuals in circulation.
In the position exemplified in figure 3, the filter is working on both sides, which makes the whole of the filter's surface disposable. At each discharge, the filter is placed, by means of an electromagnet, in such position as to present to the dirty water only one side of the filter, as shown in figure 4; the water passes through said surface and therefore leaves all residuals before washing in counter-stream the surface of the filter. At the successive discharge, the filter gets placed on the opposite side washing in counter-stream the surface of the filter previously used.
In a possible variant, for obtaining the discharge, the filter according to the present invention may be automatically controlled following to the exploitation of said pressure variation between inlet and outlet of the fluid from said filter.
The device according to the present invention, which in its structure is extremely simple, may be completely realized out of plastic and its optimal position is at the outlet of the only pump (for charging and discharging) provided in the dish washer.

Claims

A self-cleaning filter for washing machines that catches all the water circulating in the dish washer, leaving on the external surface of the filtering element all residuals found and leading to the whirlpools only the filtered water that has come together inside the filtering element, characterized in a filtering element that is partially rotated so as to open a discharge opening and closing the one for leading the water to the whirlpools, performing at the same time the counter-stream washing (with already filtered water) on one side of the filtering element.
A self-cleaning filter for washing machines, characterized in a washing treatment of the other side of the filtering element like the one according to claim 1, whereby the latter - always in discharging phase - is slightly rotated in the opposite sense.
A filter according to the precedent claims, characterized in that once the washing operation is completed the timer controlling the pump for performing the discharge, operates an electromagnet (10) that makes rotate the filter body (3) e.g. of 45°.
A filter according to the precedent claims, characterized in that in discharge position it gets placed in such a position as to show only one side, provided with a small net, to the dirty water, whereby said dirty water passes through said small net leaving there the residuals taking from the dishes; the filtered and therefore clean water is now forced to wash counter-stream the other side of the filter, from which it takes the food residuals already present on the small net and leads them to the discharge 7 which, due to the rotation of the filter body (3), is now accessible.
A filter according to claim 4, characterized in that at the same time and always due to the above mentioned rotation of the flter, the ends (5) or (6) being part of the cover (8) of the filter (3), alternatively close the passage (4) of the water to the whirlpools.
A filter according to the precedent claims, characterized in that in the following discharge, a second electromagnet (10) or othe controlling device, moves the filter body (3) in the direction opposite to the precedent one, thus allowing the counter-stream washing with clean water of the other side of the filter.
A filter according to the precedent claims characterized in that it is automatically controlled due to the exploitation of said pressure variation between the inlet and the outlet of the fluid.