GB2248768A - Dishwashing machine with discharge circuit - Google Patents

Abstract

The washing tub (3) of the dishwashing machine communicates with the intake of a discharge pump (11) by way of a vertical connecting conduit (14) having an outlet opening (17) which is connected to a subjacent calming chamber (10) which in turn is connected to said intake. At the location of the outlet opening (17) there is a deflector (15) which extends inwardly of the chamber and which is inclined with respect to the axis of the connecting tube. The deflector is also oriented towards a region of the chamber which is remote from its connection to said intake in such a way as to create within the chamber, during the phases for discharge of the operating fluid, a turbulent motion which entrains to the discharge all the particles of dirt deposited in the chamber (10). <IMAGE>

Description

DISHWASHING MACHINE WITH DISCHARGE CIRCUIT FOR THE OPERATING FLUID The present invention relates to a dishwashing machine comprising a discharge circuit for evacuation of the operating fluid contained in a tub for washing of the crockery.

As is known, the washing tub of a dishwashing machine generally accommodates in its interior a fine-mesh filter through which the operating fluid which is sprayed over the crockery by means of a circulating pump is circulated in a closed circuit. The fine-mesh filter comprises an opening, within which is preferably accommodated a wide-mesh filter which communicates the interior of the washing tub with the intake of a discharge pump. In particular, as described in GB-A-2225224, at the bottom of the tub the above-mentioned opening is associated with a subjacent substantially vertical connecting conduit which preferably communicates with the top of a chamber referred to as a 'calming chamber' which in turn is connected to the intake of the discharge pump.During the washing phases of the machine, the heavier particles of dirt in suspension in the operating liquid are deposited under the effect of gravity in the calming chamber, in the bottom of which they stagnate to be evacuated during a subsequent phase of actuation of the discharge pump.

In order to ensure that the liquid and the particles of dirt are actually in a quiet condition in the calming chamber during the washing phases and thus to ensure that the dirt is not re-circulated in the washing liquid, it is necessary for the calming chamber to be of sufficiently large dimensions. In addition, it is necessary for the above-mentioned connecting conduit to be of a sufficiently large section to permit a substantial amount of particles of dirt to be deposited in the calming chamber.

However, it can easily happen that, during a discharge phase, the speed of the flow of water which is drawn in by the discharge pump through the calming chamber is undesirably limited by the large section of the chamber itself. Consequently only a part of the dirt which is deposited on the bottom of the calming chamber is evacuated towards the discharge while the dirt which is deposited in the calming chamber at positions which are relatively remote from the intake of the discharge pump tend to accumulate and-or to be put back into circulation during the subsequent washing phases. The fine-mesh filter can then suffer from rapid clogging, which substantially affects the entire operation of the machine.

The aim of the present invention is that of providing a dishwashing machine with a simple circuit for discharge of the operating fluid, having a calming chamber in which the particles of dirt in suspension in the fluid can be effectively deposited and substantially evacuated towards the discharge.

Accordingly, a dishwashing machine is provided with a discharge circuit for the operating fluid comprising a washing tub communicating with the intake of a discharge pump by way of a substantially vertical connecting conduit having an opening which is connected to a subjacent calming chamber which in turn is connected to said intake, wherein provided substantially at the location of said outlet opening are deflector means which extend in the interior of said chamber and which are inclined with respect to the axis of said connecting tube.

The features and advantages of the invention will be clearly apparent from the following description given solely by way of non-limiting example with reference to the accompanying drawings in which: Figure 1 is a diagrammatic view of a dishwashing machine according to the invention, and Figure 2 is a diagrammatic perspective view in partial section of a detail on an enlarged scale from the dishwashing machine shown in Figure 1, in accordance with a preferred embodiment.

With particular reference to Figure 1, the dishwashing machine comprises a washing tub 3 (only part of which is shown) which is provided in its lower part with a bowl portion 4 for collecting the operating fluid, the intake section 13 of a circulating pump 5 communicating with the bottom of the bowl portion 4. The circulating pump 5 is capable of feeding at least one rotary arm assembly 6 for spraying the crockery items to be washed, in known manner.

The washing tub 3 also accommodates, below the rotary arm assembly 6, a fine-mesh recirculating filter 7 which is disposed in the path of the flow of water which, after having been sprayed over the crockery items, is collected in the bowl portion 4 in order to be freshly drawn in by the circulating pump 5.

As described for example in above-mentioned GB-A-2225224, the filter 7 comprises a substantially frustoconical portion 8 provided with a central opening 18.

The fine-mesh filter 7 further comprises a substantially cylindrical portion 9 which accommodates in its interior a wide-mesh filter 16, which is connected to the portion 8 at the bottom portion 12. The latter is in turn connected to one end of a substantially vertical connecting tube 14 whose opposite end has an outlet opening 17 connected to the intake of a discharge pump 11 by way of a chamber 10, preferably of a box-like configuration, referred to as a 'calming chamber'.

In particular, with reference also to Figure 2, the connecting tube 14 is connected to the top 19 of the chamber 10, into which it preferably penetrates over a certain distance. Preferably also the chamber 10 communicates with the intake of the discharge pump 11 at a position at its side wall 20 in per se known manner in order to limit the overall dimension of the machine in a vertical direction.

In known manner, during the washing phases of the machine, the relatively heavy particles of dirt which are removed from the crockery and which are in suspension in the fluid which is collected in the bowl portion 4 are deposited under the effect of gravity on the bottom of the chamber 10 which is in still conditions, passing from the tub 3 by way of the opening 18 of the filter 7, by way of the wide-mesh filter 16 and along the connecting tube 14.

In accordance with a feature of the invention, substantially at the location of the outlet opening 17 of the connecting tube 14, there is a least one deflector 15 or the like which extends downwardly in the interior of the chamber 10, being inclined with respect to the axis of the connecting tube 14. As will be apparent to a man skilled in the art, the angle of inclination X of the deflector may be of a variable value in dependence on the general dimensioning of the discharge circuit of the machine, in particular the capacity of the discharge pump 11 and the dimensions of the chamber 10, in order to produce the best possible performance, as described hereinafter. For example the deflector 15 is oriented towards the side surface of the chamber 10 at an angle of inclination X of about 600 with respect to the axis of the tube 14. Preferably also the deflector 15 is oriented towards a region of the chamber 10 which is remote from its connection to the intake of the discharge pump 11.

During the discharge phases therefore the pump 11 draws in water from the connecting tube 14 with a flow which, being suitably diverted by the deflector 15, is inclined in the interior of the calming chamber 10 towards a lateral region of that chamber. Thus, created in the chamber is a turbulent motion (illustrated by the arrows in Figure 2) which involves substantially the entire bottom surface of the chamber 10 and which thus entrains towards the discharge substantially all the dirt which has been previously deposited in the chamber.

In accordance with another feature of the invention the deflector 15 extends, for example from the edge of the outlet opening 17, with a surface which, in orthogonal projection, is equal to or less than half of the section of the opening 17. In that way, as has also been confirmed by experiment, the deflector 15 creates practically no obstacle to deposit in the chamber 10 of the particles of dirt coming from the connecting tube 14. In addition, during the discharge phases, any dirt which is possibly deposited on the deflector 15 is removed by virtue of the flow of water coming from the vertical tube 14, which is incident on the inclined defector 15 at a relatively high pressure. The deflector 15 is therefore advantageously self-cleaning.

As already stated, the man skilled in the art can easily determine the most appropriate angle of inclination for the deflector 15 according to the requirements involved, taking account of the fact that the resulting flow directed inwardly of the chamber 10 will be determined by the vertical component passing through the section of the opening 17 which is not affected by the deflector 15 and by the component which is diverted by the deflector.

In that connection, it is possible to provide deflector means 15 of a different type, comprising for example a deflector which is suitably shaped, for example arcuate, and/or a plurality of deflectors which are combined to produce the desired resulting flow.

It will be appreciated that the above-described dishwashing machine may be the subject of further modifications which fall within the scope of the invention.

For example, depending on the shape of the calming chamber 10, the deflector means 15 may be oriented in a different manner about a vertical axis in order to create in the chamber a turbulent flow of a more suitable configuration for removing during the discharge phases the greatest possible proportion of particles of dirt deposited therein.

Claims (4)

1. A dishwashing machine with a discharge circuit for the operating fluid comprising a washing tub communicating with the intake of a discharge pump by way of a substantially vertical connecting conduit having an opening which is connected to a subjacent calming chamber which in turn is connected to said intake, wherein provided substantially at the location of said outlet opening are deflector means which extend in the interior of said chamber and which are inclined with respect to the axis of said connecting tube.

2. A dishwashing machine according to claim 1 wherein said deflector means are oriented towards a region of said chamber which is remote from its connection to the intake of said discharge pump.

3. A dishwashing machine according to claim 1 or 2 wherein said deflector means extend at a position corresponding to said outlet opening with a surface which in orthogonal projection is equal to or less than half the section of the opening.

4. A dishwashing machine constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.