WO2017114558A1

WO2017114558A1 - A dishwasher

Info

Publication number: WO2017114558A1
Application number: PCT/EP2015/081329
Authority: WO
Inventors: Mehmet DIKSAN; Orhan Atabey; Mahmut Murat GOCMEN; Hasret GURSOY; Doruk TURGUL
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2015-12-29
Filing date: 2015-12-29
Publication date: 2017-07-06
Anticipated expiration: 2018-06-29

Abstract

The present invention relates to a dishwasher (1) comprising: - a tub (2) in which the dishes to be washed are placed; - a hydraulic circuit (3) for circulating washing liquid through the tub (2), connectable to an external source of water and having at least a lower rotatable spray arm (4) and an upper rotatable spray arm (5) arranged in the tub (2) to spray the dishes with the washing liquid, a sump (7) which is arranged in the lower section of the tub (2) to collect the washing liquid that has been sprayed on the dishes during washing operation, a first duct (8) and a second duct (9) for conveying the washing liquid from the sump (7) respectively to the lower spray arm (4) and to the upper spray arm (5); and - a valve arranged on the hydraulic circuit (3) for allowing to selectively deliver the washing liquid from the sump (7) to the first duct (8) toward the lower spray arm (4) or to the second duct (9) toward the upper spray arm (5).

Description

A DISHWASHER

This invention relates to a dishwasher having improved efficiency, in particular with reference to the water usage, and improved washing performances.

As it is known dishwashers generally comprise a tub in which the dishes to be washed are placed and a hydraulic circuit for circulating washing liquid through the tub.

The hydraulic circuit is connectable to an external source of water and has an upper rotatable spray arm and a lower rotatable spray arm arranged in the tub to spray the dishes with the washing liquid, a sump which is arranged in the lower section of the tub to collect the washing liquid that has been sprayed on the dishes during washing operation, and ducts for conveying the filtered washing liquid from the sump to the spray arms.

During the washing operation, in order to limit the water consumption and to ensure at the same time that a sufficient amount of washing liquid is sprayed onto the dishes, the washing liquid is alternatively delivered to the lower spray arm or to the upper spray arm. To this aim, the dishwashers comprise a valve arranged on the hydraulic circuit for allowing to selectively deliver the washing liquid to the lower spray arm or to the upper spray arm, through the respective conveying ducts.

An example of such a dishwasher is disclosed in the patent application n. US 2007/0119488 A1.

Leakages of washing liquid often occur, due for instance to malfunctioning of the valve or to other technical reasons, so that the washing liquid, instead of being delivered only to the selected duct to reach the correspondent spray arm, is partially delivered also to the other duct. This reduces the washing efficiency of the selected spray arm, since a lower amount of washing liquid reaches it and is hence sprayed onto the dishes. Moreover a higher amount of water has to be drawn into the tub, in order to compensate the leakage and prevent malfunctioning of the circulation pump.

At the moment no solution has been provided for overcoming such technical problem.

An objective of the present invention is to provide a dishwasher having an improved efficiency in the use of water and hence requiring a lower consumption of water and ensuring an improved washing efficiency.

This objective has been achieved by the dishwasher as defined in claim 1. Further achievements have been attained by the subject-matters respectively defined in the dependent claims.

The dishwasher realized in order to attain the aim of the present invention comprises one or more apertures which are provided on the duct connecting the sump with the upper spray arm, in order to discharge back into the sump the washing liquid accidentally conveyed into such duct due to leakage phenomena.

In an embodiment the aperture on the duct is arranged over the sump in order for the washing liquid accidentally conveyed into it to be more quickly and easily discharged directly into the sump.

In order to favor the quick discharge of the leaked washing liquid back into the sump, in a further embodiment the screen filter placed over the sump has through holes arranged below the aperture on the duct.

In another embodiment the apertures are provided on the lower portion of the duct substantially parallel to the bottom wall of the tub, so as to discharge the leaked washing liquid as soon as the latter penetrates into the duct.

According to an embodiment, the apertures are arranged on the lower wall of the duct, while according to a further embodiment they are arranged on the upper wall of the duct.

In an embodiment, the hydraulic circuit comprises obstruction means arranged on the duct to obstruct the apertures when the washing liquid is intentionally introduced into the duct and it has, therefore, a pressure that exceeds a preset value.

In a further embodiment, the obstruction means comprises a flap mounted inside the duct, rotatably attached to its upper wall and movable between an open position in which it allows washing liquid to flow through the at least one aperture and a closed position in which it blocks the passage of washing liquid through the at least one aperture.

The flap, in particular, is movable toward the open position by means of the gravity force acting on it and it is movable toward the closed position by means of the pressure force of the washing liquid flowing into the duct acting on it.

In an embodiment, the duct has a plurality of apertures and the flap is designed to cover all the apertures when it is in the closed position.

In a different embodiment, the duct has one aperture and the obstruction means comprises a hollow element defining a displacing chamber, arranged on the duct in correspondence of the aperture and having an opening aligned with the aperture. The obstruction means further comprises an obstruction element arranged in the displacing chamber, having dimensions bigger than the dimensions of the aperture and of the opening and displaceable in the displacing chamber between an open position in which it allows washing liquid to flow through the aperture and the opening and a closed position in which it blocks the passage of washing liquid through the aperture or the opening.

In an embodiment, the obstruction element has a density which is higher than the density of the water.

In particular, the obstruction element is movable toward the open position by means of the pressure force of the washing liquid acting on it and exceeding the gravity force acting on it and it is movable toward the closed position by means of the pressure force of the washing liquid acting on it when such pressure force exceeds a preset value.

In a further embodiment, the obstruction means further comprises at least one elastically deformable element connected to the hollow element and to the obstruction element to keep the latter in the open position.

In particular in this case, the obstruction element is movable toward the closed position by means of the pressure force of the washing liquid acting on it when such pressure force exceeds the elastic restoring force of the at least one elastically deformable element.

Additional advantages of the dishwasher of the present invention will become apparent with the detailed description of the embodiments with reference to the accompanying drawings in which:

Figures 1 and 2 – are respectively a perspective view of a dishwasher according to the present invention wherein the lower spray arm and the lower rack have been removed in order to show further technical features of the dishwasher and an enlarged particular thereof.

Figures 3 and 4 – are respectively a perspective view of a hydraulic circuit of a dishwasher according to the present invention and an enlarged particular thereof.

Figure 5 – is a perspective sectional view of a particular of a hydraulic circuit of a dishwasher of the present invention according to an embodiment.

Figure 6 – is a perspective sectional view of a particular of a hydraulic circuit of a dishwasher of the present invention according to a different embodiment.

Figures 7 and 8 – are two sectional perspective views of a particular of a hydraulic circuit of a dishwasher of the present invention according to a further different embodiment with a flap of obstruction means thereof respectively in a closed and in an open position.

Figure 9 – is an enlarged perspective view of a particular of the hydraulic circuit of Figures 7 and 9, with the flap in the open position.

Figure 10 – is a perspective view of a particular of a hydraulic circuit of a dishwasher of the present invention according to a further different embodiment.

Figure 11 – is a cross-sectional view of the hydraulic circuit of Figure 10.

Figures 12 and 13 – are an enlarged particular of the cross-sectional view of the hydraulic circuit of Figure 11 relative to obstructing means respectively in an open and in a closed position.

Figure 14 – is an enlarged cross-sectional view of a particular of the hydraulic circuit of Figure 10 according to a different version of this embodiment.

Elements shown in figures are numbered as follows.

Dishwasher
Tub
Hydraulic circuit
Lower spray arm
Upper spray arm
Upper rack
Sump
First duct
Second duct
Screen filter
Aperture
Through holes
Bottom wall
Lateral walls
Rear wall
Lower portion of the second duct
Upper portion of the second duct
Upper wall
Lower wall
Obstruction means
Flap
Abutment protrusion
Hollow element
Displacing chamber
Opening
Obstructing element
Elastically deformable element

The dishwasher 1 comprises a tub 2 in which the dishes to be washed, i.e. dishes, kitchenware, tableware, crockery etc. to be washed, are placed, and a hydraulic circuit 3, connectable to an external source of water, for circulating washing liquid through the tub 2.

The hydraulic circuit 3 has at least a lower rotatable spray arm 4 and an upper rotatable spray arm 5 which are arranged in the tub 2 to spray the dishes with the washing liquid. More in detail, according to a preferred embodiment illustrated in Figure 1, the dishwasher 1 comprises a lower rack (not illustrated) and an upper rack 6 which are extendably disposed into the tub 2 one above the other to be loaded by the user with the dishes to be washed and which are associated respectively with the lower rotatable spray arm 4 and with the upper rotatable spray arm 5.

The hydraulic circuit 3 further comprises a sump 7 which is arranged in the lower section of the tub 2 to collect the washing liquid that has been sprayed on the dishes during washing operation, i.e. during the washing and rinsing steps that are performed in order to clean the dishes, and a first duct 8 and a second duct 9 for conveying the washing liquid from the sump 7 respectively to the lower spray arm 4 and to the upper spray arm 5.

In a preferred embodiment, the hydraulic circuit 3 comprises a screen filter 10 placed over the sump 7 to hold at least the coarser particles carried by the washing liquid and advantageously a further microfilter (not illustrated) arranged in the sump 7 to hold the finer particles and soil. The screen filter 10 and microfilter allow to prevent the dirt from getting into the circulation during washing, which dirt would decrease the effectiveness of washing.

The dishwasher 1 further comprises a valve (not illustrated), in particular a diverter valve, arranged on the hydraulic circuit 3 for allowing to selectively deliver the washing liquid to the lower spray arm 4 and/or to the upper spray arm 5, respectively through the first duct 8 and/or through the second duct 9.

The dishwasher 1 further comprises a circulation pump (not illustrated), arranged on the hydraulic circuit 3 downward of the sump 7, with respect to the flowing direction of the washing liquid in the hydraulic circuit 3, to draw the washing liquid from the sump 7 toward the lower and

upper spray arms

4 and 5 respectively through the first and

second duct

8 and 9.

According to the invention, the second duct 9 has one or more apertures 11 for discharging into the sump 7 the washing liquid accidentally conveyed into it, thus reintroducing such washing liquid in the recirculation.

As previously specified, in fact, malfunctioning of the valve or other technical reasons, such as for instance defects or damages on gasket and sealing means, can lead to a partial leakage of the washing liquid toward the second duct 9 while it should be completely conveyed into the first duct 8 and toward the lower spray arm 4.

The presence of the aperture or apertures 11 on the second duct 9 ensures that substantially all the washing liquid directed to the lower spray arm 4 actually reaches it, thus improving the washing performances of the latter and more in general of the dishwasher 1 and entailing a better exploitation of the water introduced in the tub 2 for the washing operation. Moreover, by maintaining the whole volume of washing liquid recirculating and avoiding the accumulation of washing liquid in the second duct 9, malfunctioning of the circulation pump are avoided.

In an embodiment, the aperture (or apertures) 11 is arranged over the sump 7, i.e. more clearly on a portion of the second duct 9 that is positioned above the sump 7, in order for the washing liquid accidentally conveyed into the second duct 9 to be discharged directly into the sump 7. The aperture (or apertures) 11 such arranged allows the washing liquid to drop from the second duct 9 directly into the sump 7, thus favoring its reintroduction in the recirculation.

In a version of this embodiment, the screen filter 10 placed over the sump 7 has one or more through holes 12 arranged below the aperture (or apertures) 11 of the second duct 9 for allowing the washing liquid discharged from it to be directly introduced into the sump 7. The presence of the through holes 12 on the screen filter 10 allows a more quick reintroduction of the washing liquid dropping off the second duct 9 in the sump 7 and hence in the recirculation.

As illustrated in Figure 1, the dishwasher 1 comprises a bottom wall 13, two lateral walls 14 and a rear wall 14 delimiting, together with an upper wall and a frontal door, the tub 2. The sump 7 is mounted underneath an opening on the bottom wall 13 and the screen filter 10 is mounted on the bottom wall 13 over the sump 7.

According to an embodiment, the second duct 9 comprises a lower portion 16, which is advantageously essentially horizontal and which extends substantially parallel to the bottom wall 13 and an upper portion 17, which is advantageously essentially vertical and which extends substantially parallel to one of the lateral walls 14 or to the rear wall 15. The aperture (or apertures) 11 are arranged on the lower portion 16 of the second duct 9. This allows the washing liquid that drops off the second duct 9 to be more quickly and easily collected in the sump 7.

The lower portion 16 of the second duct 9 comprises an upper wall 18 and a lower wall 19.

According to an embodiment illustrated in Figures 5 and 6, the aperture 11 or the apertures 11 are arranged on the lower wall 19 of the lower portion 16 of the second duct 9, so that the washing liquid accidentally conveyed into the second duct 9 can easily be expelled through the apertures, by flowing through them due to gravity.

When the washing liquid is intentionally introduced in the second duct 9, the higher pressure of the liquid allows only a negligible part of the washing liquid to be expelled from the second duct 9 through the aperture 11 or the apertures 11.

According to a different embodiment, the aperture 11 or the apertures 11 are arranged on the upper wall 18 of the lower portion 16 of the second duct 9. Due to the narrow transversal section of the second duct 9 the washing liquid accidentally conveyed into it tends to exit from the second duct 9 through the aperture 11 or apertures 11, although the latter are arranged on the upper wall 18 of the second duct 9. This allows moreover to further hinder part of the washing liquid intentionally introduced in the second duct 9 from being expelled from the second duct 9.

In an embodiment illustrated in particular in Figures 7-14, the hydraulic circuit 3 comprises obstruction means 20 arranged on the second duct 9 and designed to obstruct the aperture or apertures 11 when the washing liquid flowing into the second duct 9 has a pressure that exceeds a preset value, such as when pressurized washing liquid is intentionally conveyed into the second duct 9. The obstruction means 20 further ensures that no washing liquid is expelled from the second duct 9 when intentionally conveyed into it, while allowing low pressure washing liquid, such as the washing liquid entering into the second duct 9 due to leakage phenomena, to be expelled from the second duct 9.

In an embodiment illustrated in Figures 7-9, the obstruction means 20 comprises a flap 21 mounted inside the second duct 9, rotatably attached to the upper wall 18 of the lower portion 16 of the second duct 9, upstream of the aperture or apertures 11 with respect to the flow direction of the washing liquid into the second duct 9. The flap 21 is movable between an open position O, illustrated in Figure 8, in which it allows washing liquid to flow through the aperture or apertures 11 to exit the second duct 9, and a closed position C, illustrated in Figure 7, in which it blocks the passage of washing liquid through the aperture or apertures 11, by covering them. In particular the flap 21 is preferably hinged to the upper wall 18.

According to an embodiment illustrated in Figure 7-9, in order to ensure a better tightness, the upper wall 18 of the lower portion 16 of the second duct 9 is internally provided with an abutment protrusion 22, against which the flap 21 abuts when in the closed position C.

More in detail, the flap 21 is movable toward the open position O by means of the gravity force acting on it and it is movable toward the closed position C by means of the pressure force of the washing liquid flowing into the second duct 9 acting on it and, more specifically on a face of the flap 21. Operationally, when low pressure washing liquid penetrates into the second duct 9 due to leakage, the pressure exerted by the washing liquid on the flap 21 is not sufficient to overcome the gravity force acting on it and keeping hence the flap 21 in the open position O so that the washing liquid can penetrates between the second duct 9 and the flap 21 and into the aperture or apertures 11 and escape through the latter. Differently, when high pressure washing liquid penetrates into the second duct 9, as it happens when the washing liquid is intentionally conveyed into the second duct 9, the pressure force exerted by the washing liquid on the flap 21 exceeds the gravity force, thus forcing the flap 21 toward the closed position C.

In an embodiment, the second duct 9 has a plurality of apertures 11 and the flap 21 is designed to cover all the apertures 11 when in the closed position C, as illustrated in the attached Figures 7-9. Obviously, the obstruction means 20 may differently comprise more than one flap 21 to close all the apertures 11, without departing from the scope of the present invention.

According to an embodiment illustrated in Figures 10-14, the second duct 9 has one aperture 11 and the obstruction means 20 comprises a hollow element 23 defining, together with a portion of the second duct 9, a displacing chamber 24, arranged on the upper wall 18 of the lower portion 16 of the second duct 9 in correspondence of the aperture 11 and having an opening 25 aligned with the aperture 11, in particular arranged below or above the aperture 11. According to this embodiment, the obstruction means 20 further comprises an obstruction element 26, such as in particular a ball as illustrated in the attached figures, arranged in the displacing chamber 24, having dimensions, and in particular the diameter in the case of the ball, bigger than the dimensions of the aperture 11 and of the opening 25 so as to be movable within the displacing chamber 24 but trapped into it without possibility to be expelled through the aperture 11 or the opening 25. The obstruction element 26 is displaceable within the displacing chamber 24 between an open position O in which it allows washing liquid to flow through the aperture 11 and the opening 25 to exit the second duct 9, and a closed position C in which it blocks the passage of washing liquid through the aperture 11 or the opening 25, by covering one or the other.

According to the embodiment illustrated in Figures 10-14, the hollow element 23 is arranged on the upper wall 18 externally of the second duct 9, with its opening 25 above the aperture 11. This allows not to reduce the transversal section of the second duct 9 in correspondence of the obstruction means 20. Differently, the hollow element 23 could be arranged internally of the second duct 9, with its opening 25 below the aperture 11.

In particular, the obstruction element 26 has a density which is higher than the density of the water so that it does not float on the water or on the washing liquid, whose density is substantially equal to the density of the water.

Advantageously, the obstruction element 26 is movable toward the open position O by means of the pressure force of the washing liquid acting on it and exceeding the gravity force acting on it and it is movable toward the closed position C by means of the pressure force of the washing liquid acting on it when such pressure force exceeds a preset value. More clearly the obstruction element 26 is designed so as to be displaceable in the displacing chamber 24, and in particular to be removable from the aperture 11 in the embodiment illustrated in the attached Figures 10-14, but not to be pressed against the opening 25, by means of the pressure applied by low pressure washing liquid, as the washing liquid entering into the second duct 9 due to leakage phenomena. The obstruction element 26 is moreover designed in order to be pressed against the opening 25 by means of the pressure force applied by higher pressure washing liquid, as the washing liquid intentionally conveyed into the second duct 9.

Therefore, operationally, the washing liquid entering the second duct 9 due to leakage penetrates through the aperture 11 and the opening 25, by slightly displacing the obstructing element 26 in the displacing chamber 24 and removing it from the aperture 11, thus exiting the second duct 9. Differently, when high pressure washing liquid is conveyed into the second duct 9, such liquid displaces the obstruction element 26 pushing it toward the opening 25, thus preventing washing liquid from exiting the second duct 9.

In a version of this embodiment, the obstruction means 20 further comprises one or more elastically deformable elements 27, such as one or more springs, connected to the hollow element 23 and to the obstruction element 26 to keep the latter in the open position O.

In this case the obstruction element 26 is movable toward the closed position C by means of the pressure force of the washing liquid acting on it when such pressure force exceeds the elastic restoring force of the at elastically deformable element or elements 27. This helps the low pressure washing liquid introduced in the second duct 9 due to leakage to exit the second duct 9, since no pressure force is requested for displacing the obstruction element 26 toward the open position O, moving it from the aperture 11, and for allowing hence the washing liquid to penetrates through the aperture 11 and the opening 25.

The dishwasher 1 according to the invention allows therefore to efficiently use, during the different phases of the washing operation, the whole volume of water introduced into the tub 2, preventing the dispersion of fractions of this volume of water due to leakage phenomena.

Claims

A dishwasher (1) comprising:

- a tub (2) in which the dishes to be washed are placed;

- a hydraulic circuit (3) for circulating washing liquid through the tub (2), connectable to an external source of water and having at least a lower rotatable spray arm (4) and an upper rotatable spray arm (5) arranged in the tub (2) to spray the dishes with the washing liquid, a sump (7) which is arranged in the lower section of the tub (2) to collect the washing liquid that has been sprayed on the dishes during washing operation, a first duct (8) and a second duct (9) for conveying the washing liquid from the sump (7) respectively to the lower spray arm (4) and to the upper spray arm (5);

- a valve arranged on the hydraulic circuit (3) for allowing to selectively deliver the washing liquid from the sump (7) to the first duct (8) toward the lower spray arm (4) or to the second duct (9) toward the upper spray arm (5);

characterized in that the second duct (9) has at least one aperture (11) for discharging into the sump (7) the washing liquid accidentally conveyed into it.
A dishwasher (1) as in Claim 1, characterized in that the at least one aperture (11) is arranged over the sump (7) in order for the washing liquid accidentally conveyed into the second duct (9) to be discharged directly into the sump (7).
A dishwasher (1) as in Claim 2, characterized in that it further comprises a screen filter (10) placed over the sump (7) and having at least one through hole (12) arranged below the at least one aperture (11) of the second duct (9) for allowing the washing liquid discharged from it to be directly introduced into the sump (7).
A dishwasher (1) as in any of the preceding claims, characterized in that it comprises a bottom wall (13), two lateral walls (14) and a rear wall (15) delimiting the tub (2), the second duct (9) comprising a lower portion (16) extending substantially parallel to the bottom wall (13) and an upper portion (17) extending substantially parallel to one of the lateral walls (14) or to the rear wall (15) and the at least one aperture (11) being arranged on the lower portion (16) of the second duct (9).
A dishwasher (1) as in Claim 4, characterized in that the lower portion (16) of the second duct (9) comprises a lower wall (19) and the at least one aperture (11) is arranged on such lower wall (19).
A dishwasher (1) as in Claim 4, characterized in that the lower portion (16) of the second duct (9) comprises an upper wall (18) and the at least one aperture (11) is arranged on such upper wall (18).
A dishwasher (1) as in any of the preceding claims, characterized in that the hydraulic circuit (3) comprises obstruction means (20) arranged on the second duct (9) and designed to obstruct the at least one aperture (11) when the washing liquid flowing into the second duct (9) has a pressure that exceeds a preset value.
A dishwasher (1) as in Claims 6 and 7, characterized in that the obstruction means (20) comprises a flap (21) mounted inside the second duct (9) rotatably attached to its upper wall (18), upstream of the at least one aperture (11) with respect to the flow direction of the washing liquid into the second duct (9), and movable between an open position (O) in which it allows washing liquid to flow through the at least one aperture (11) and a closed position (C) in which it blocks the passage of washing liquid through the at least one aperture (11).
A dishwasher (1) as in Claim 8, characterized in that the flap (21) is movable toward the open position (O) by means of the gravity force acting on it and it is movable toward the closed position (C) by means of the pressure force of the washing liquid flowing into the second duct (9) acting on it.
A dishwasher (1) as in Claim 8 or 9, characterized in that the second duct (9) has a plurality of apertures (11) and the flap (21) is designed to cover all the apertures (11) of the second duct (9) when in the closed position (C).
A dishwasher (1) as in Claims 6 and 7, characterized in that the second duct (9) has one aperture (11) and the obstruction means (20) comprises a hollow element (23) defining a displacing chamber (24), arranged on the upper wall (18) of the second duct (9) in correspondence of the aperture (11) and having an opening (25) aligned with the aperture (11), and an obstruction element (26) arranged in the displacing chamber (24), having dimensions bigger than the dimensions of the aperture (11) and of the opening (25) and displaceable in the displacing chamber (24) between an open position (O) in which it allows washing liquid to flow through the aperture (11) and the opening (25) and a closed position (C) in which it blocks the passage of washing liquid through the aperture (11) or the opening (25).
A dishwasher (1) as in Claim 11, characterized in that the obstruction element (26) has a density which is higher than the density of the water.
A dishwasher (1) as in Claim 12, characterized in that the obstruction element (26) is movable toward the open position (O) by means of the pressure force of the washing liquid acting on it and exceeding the gravity force acting on it and it is movable toward the closed position (C) by means of the pressure force of the washing liquid acting on it when such pressure force exceeds a preset value.
A dishwasher (1) as in Claim 11, characterized in that the obstruction means (20) further comprises at least one elastically deformable element (27) connected to the hollow element (23) and to the obstruction element (26) to keep the latter in the open position (O).
A dishwasher (1) as in Claim 14, characterized in that the obstruction element (26) is movable toward the closed position (C) by means of the pressure force of the washing liquid acting on it when such pressure force exceeds the elastic restoring force of the at least one elastically deformable element (27).