Dishwasher comprising an automatic door opening mechanism

Abstract

A dishwasher comprising a housing (2) provided with an opening (3), a door (5) hinged to the bottom portion of a housing (2) and closing the opening (3), a latch (6) holding the door (5) in the closed position, an automatic door opening mechanism (7) mounted on the housing (2); the automatic door opening mechanism comprising a housing (8), a linear actuator (9) having a longitudinal push shaft (10), a two-leg lever (11) pivotally mounted in the housing (8), a push bar (12) provoking the latch (6) to unlatch, the two-leg lever (11) being arranged within the housing (8) substantially downstream of the linear actuator (9) between the linear actuator (9) and the push bar (12), viewed in the direction of action of the door (5) opening force, the two-leg lever (11) being in direct contact with the push shaft (10) of the linear actuator at one end and with the push bar (12) at the other.

Description

[0001] Dishwasher comprising an automatic door opening mechanism

[0002] Subject of invention

[0003] The subject of the present invention is a dishwasher comprising an automatic door opening mechanism.

[0004] Prior art

[0005] In a dishwasher, the dishwashing process usually ends with a drying phase of the washed and wet dishes. Therefore, the space in which the dishes are arranged is heated to a sufficiently high temperature for the liquid to evaporate and the dishes to dry. To reduce energy consumption, the dishwasher has a built-in automatic door opening mechanism which partially opens the door during the drying phase. Door opening facilitates the hot and water vapour- saturated air to escape, so that a lower water heating temperature is required for drying during the final rinse phase. This reduces energy consumption. Due to the evacuation of the water vapour- saturated air, water vapour is not discharged on the surface of the dishes when the air in the space filled with the dishes is cooled, this is why the surface of the dishes is free of water spots. The door is opened by an automatic door opening mechanism. An external force, often in the form of an electrical signal, actuates an actuator which is part of the mechanism. The actuator acts on the pusher and forces it towards the dishwasher door with a force greater than the force of the latch holding the door closed. The actuator in the mechanism remains actuated for a predetermined time sufficient to open the door. When the actuator stops its actuation, the door still remains open. However, it may happen that the user attempts to close the door while the actuator is still in the active phase. As the actuator forcing the pusher against the door is still acting, the counteracting force exerted by the user to close the door may result in damage to individual parts of the entire door opening mechanism as well as damage to the door. In order to prevent possible damage to individual parts of the dishwasher while the actuator is actuated, the automatic door opening mechanism comprises an element which absorbs the force exerted by the user when closing the door. The force absorbing element is usually an additional spring element in the form of a coil spring incorporated in the mechanism. Such a system is disclosed for instance in EP 2568864 Al (Kilic).

[0006] Technical problem

[0007] The technical problem is to provide a dishwasher comprising an automatic door opening mechanism, which mechanism should be configured to prevent damages to the mechanism or other parts of the dishwasher in the event when the user attempts to close the door while the actuator is still acting. The automatic door opening mechanism must be configured in a way to be simple to produce and consist of as few components as possible and be economically viable.

[0008] Solution to the technical problem

[0009] The relative expressions such as front, rear, upper, lower, etc. are herein defined from the perspective of the dishwasher user, when the dishwasher is in its functional state.

[0010] The technical problem is solved by the dishwasher, the main characteristics of which are defined in claim one.

[0011] The dishwasher comprises a housing provided with an opening, through which a chamber to receive the dishes to be washed is received; a door hinged to the bottom portion of the housing that closes the opening; a latch holding the door in the closed position; an automatic door opening mechanism mounted on the housing, in its upper portion, the automatic door opening mechanism comprising a housing; a linear actuator arranged in the housing and having a longitudinal push shaft, the longitudinal axis of the linear actuator and the longitudinal push shaft extending in parallel to an upper edge of the door; a two-leg lever pivotally mounted in the housing; a push bar provoking the latch to unlatch and open the dishwasher door, the two-leg lever being arranged within the housing substantially downstream of the linear actuator between the linear actuator and the push bar, viewed in the direction of action of the door opening force, the two-leg lever being in direct contact with the push shaft of the linear actuator at one end and with the push bar at the other.

[0012] The dishwasher has the two-leg lever configured as an elastic element which absorbs the push force created upon undesirable door closing and gets elastically deformed, the push force of the undesirable door closing being higher than the push force of the linear actuator upon the automatic door opening, the two-leg lever being at the same time configured as a rigid element that transfers the push force of the linear actuator upon the automatic door opening to the push bar without getting deformed. The push bar is configured as a rigid element.

[0013] In the automatic door opening mechanism, an oblong guide cavity is formed in a material-locking manner to receive the push bar and is positioned at a distance from the linear actuator and perpendicularly to the push shaft. The push bar is longer than the guide cavity.

[0014] The two-leg lever has a pivot, through which it is pivotally mounted on the mechanism housing, a short leg and a long leg. The short leg and the long leg are spaced at an angle of 50° 160°. The short leg of the two-leg lever bears with its end on the longitudinal shaft of the linear actuator and forms a swivel connection therewith. The long leg of the two-leg lever is provided at its free end with a guide groove to receive a plug arranged at a first end of the push bar, the guide groove and the plug forming a swivel connection between the long leg and the push bar.

[0015] The two-leg lever is made of a material having such tensile strength and elastic deformation that impart the two-leg lever sufficient rigidity at forces 20-80 N and adequate elastic deformation at forces 120-170 N. The material of the two-leg lever may be a plastic material, such as polyoxymethylenes, or an iron or aluminium based metal material.

[0016] The dishwasher of the present invention comprises an automatic door opening mechanism that allows the door to open at a certain angle or gap in a certain dishwashing phase to facilitate discharge of water-vapour saturated hot air. At the same time, the mechanism is configured in a way to simply, yet efficiently and safely, prevents damages to components of the mechanism or even the dishwasher door. The simplicity of the components and their low number make the production of the mechanism simple and also economically viable.

[0017] The dishwasher of the invention will be described hereinbelow in more detail by way of an embodiment and drawings representing in

[0018] Fig. 1 schematic illustration of the dishwasher comprising an automatic door opening mechanism,

[0019] Fig. 2 an automatic door opening mechanism.

[0020] A dishwasher 1 comprises a housing 2 provided with an opening 3, through which a chamber 4 for the dishes to be washed are loaded, a door 5 closing the opening 3 and being hinged to the bottom portion of the housing 2, a latch 6 holding the door 5 in the closed position, and an automatic door opening mechanism 7 mounted in the upper portion of the housing 2.

[0021] The automatic door opening mechanism 7 comprises a housing 8 mounted in the upper portion of the dishwasher housing 2 and adjacent to the latch 6, a linear actuator 9 arranged in the housing 8 and having a longitudinal push shaft 10, a two-leg lever 11 pivotally mounted in the housing 8, and a push bar 12 provoking the latch 6 to unlatch and open the dishwasher door 5 by a certain angle or gap which facilitates the discharge of the water- vapour saturated hot air.

[0022] The linear actuator 9 is arranged in the mechanism housing 8 such that its longitudinal axis and the push shaft 10 extend in parallel to an upper edge 23 of the door. In the embodiment, the linear actuator 8 is configured as a thermal wax actuator, but is not limited to this type. The linear actuator 8 may be configured in any known shape and may be actuated by an electric signal. At a distance from the linear actuator 9 and perpendicularly to the push shaft 10, an oblong guide cavity 16 that receives the push bar 12 is formed in a material-locking manner within the mechanism housing 8. The push bar 12 which is longer than the guide cavity 16 reaches with its first end 20 into the guide cavity 16, while another end 21 of the push element projects out of the guide cavity 16 and out of the housing 8.

[0023] Between the linear actuator 9 and the push bar 12 there is arranged the two-leg lever 11 having a short 13 and a long leg 14, the legs 13, 14 being spaced apart by an angle of 50° 160° to substantially form an L. The two-leg lever 11 has a pivot 15, through which it is pivotally mounted on the mechanism housing 8. The two -leg lever 11 is arranged within the mechanism housing 8 substantially downstream of the linear actuator 9, viewed in the direction of action of the door opening force, such that the longitudinal push shaft 10 of the linear actuator 9 bears on the short leg 13 of the lever, preferably on its end 22, or forms a swivel connection therewith. A long leg end 17 has a guide groove 18 to receive a plug 19 arranged at the first end 20 of the push bar. The long leg 14 and the push bar 12 have a swivel connection such that the swivelling of the long leg 14 of the two-leg lever causes the push bar 12 to move in the longitudinal direction and out of the guide cavity 16.

[0024] The linear thermal actuator 9 is actuated in the drying phase. The thermal element of the actuator, which is wax in the present embodiment, changes its state under the influence of heat from solid to liquid, which increases the volume of the thermal element and consequently the force acting on the push shaft 10. The push shaft 10 linearly moves in the longitudinal direction and its movement causes the two -leg lever 11 to swivel. The swivel connection between the long leg 14 of the two-leg lever and the push bar 12 causes the latter to move longitudinally away from the automatic door opening mechanism 7 and towards the dishwasher door 5. The push force, with which the push bar 12 acts on the door 5, is greater than the force of the latch 6 holding the door 5 in the closed position and amounts to 20-80 N. The latch 6 is unlatched, the door 5 is open for a certain angle or gap, which facilitates the discharge of the watervapour saturated hot air.

[0025] It is recommended for the door 5 to remain open for a certain period of time, 40 minutes for instance, for the water- vapour saturated hot air to be discharged from the dishwasher. If desired, the user may, however, close the automatically opened door. When the user wishes to close the door 5 in the initial drying phase, the linear actuator is still actuated. The user closes the door 5 with a certain push force which acts in a direction opposite the direction of the push bar 12 in the automatic door opening. The user’s push force acting on the push bar 12 in the opposite direction may amount to 120 to 160 N in the undesired door closing. As a result, the rigid push bar 12 retracts into the interior of the guide cavity 16 of the mechanism. At the same time, the first end 20 of the push bar acts on the end 17 of the long leg of the two-leg lever with a push force in the opposite direction. The two-leg lever 11 is configured as an elastic element absorbing the push force acting in the opposite direction. The push bar 12 pushes the end 17 of the long leg 14 of the two -leg lever towards the machine interior, the long leg 14 is elastically deformed and gets sagged. The long leg 14 and consequently the whole two-leg lever 11 absorb the closing force, getting elastically deformed. At the same time, the two-leg lever 11 is sufficiently rigid to withstand the force of the linear actuator 9 on the push bar 12 without getting deformed, such that the latch 6 unlatches in the automatic door opening phase. The elastic two-leg lever 11 prevents damage to the automatic door opening mechanism 7, other dishwasher components and also the door 5 in case the door 5 is closed, while the linear actuator is still actuated.

[0026] The two-leg lever 11 is formed of a material having such tensile strength and elastic deformation that impart the two-leg lever 11 sufficient rigidity at forces 20-80 N and adequate elastic deformation at forces 120-170 N. The materials may also be iron or aluminium based metal or plastic. Preferred are plastic materials due to their lower specific weight, adequate mechanical properties and simple machinability, such as polyoxymethylenes.

[0027] The linear actuator 9 is actuated for a predetermined limited period of time which is sufficient for the door to open and allow the water-vapour saturated hot air to be discharged from the dishwasher. The linear actuator 9 is deactivated after a predetermined period of time, which, when the door 5 is being closed, allows the push shaft 10 to return linearly into the interior of the linear actuator and the two-leg lever 11 to swivel without getting elastically and plastically deformed. In case of a thermal linear actuator 9 integrated in the mechanism 7 of the invention, the actuator remains active also after a direct switch-off. The thermal element, which is wax, reassumes its original, solid aggregate state with a reduced volume with a time delay. As a result, the mechanism 7 is protected against undesired deformation caused by the door being closed in the drying phase even after the linear actuator has been deactivated.

Claims

Claims1. A dishwasher comprising:- a housing (2) provided with an opening (3), through which a chamber (4) to receive the dishes to be washed is received,- a door (5) hinged to the bottom portion of a housing (2) and closing the opening (3),- a latch (6) holding the door (5) in the closed position,- an automatic door opening mechanism (7) mounted on the housing (2) in its upper portion, the automatic door opening mechanism (7) comprising a housing (8), a linear actuator (9) arranged in the housing (8) and having a longitudinal push shaft (10), the longitudinal axis of the linear actuator (9) and the longitudinal push shaft (10) extending in parallel to an upper edge (23) of the door (5), a two-leg lever (11) pivotally mounted in the housing (8), a push bar (12) provoking the latch (6) to unlatch and open the dishwasher door (5), characterized in that the two-leg lever (11) is arranged within the housing (8) substantially downstream of the linear actuator (9) between the linear actuator (9) and the push bar (12), viewed in the direction of action of the door (5) opening force, the two-leg lever (11) being in direct contact with the push shaft (10) of the linear actuator at one end and with the push bar (12) at the other.

2. The dishwasher according to claim 1, characterized in that the two-leg lever (11) is configured as an elastic element which absorbs the push force created upon inadvertent door closing and gets elastically deformed, the push force of the inadvertent door closing being higher than the push force of the linear actuator upon the automatic door opening, the two-leg lever (11) being at the same timeconfigured as a rigid element that transfers the push force of the linear actuator (9) upon the automatic door opening to the push bar (12) without getting deformed.

3. The dishwasher according to any of the preceding claims, characterized in that the push bar (12) is configured as a rigid element.

4. The dishwasher according to any of the preceding claims, characterized in that in the housing (8) of the automatic door opening mechanism an oblong guide cavity (16) is formed in a material-locking manner to receive the push bar (12) and is positioned at a distance from the linear actuator (9) and perpendicularly to the push shaft (10).

5. The dishwasher according to claim 3, characterized in that the push bar (12) is longer than the guide cavity (16).

6. The dishwasher according to any of the preceding claims, characterized in that the two-leg lever (11) has a pivot (15), through which it is pivotally mounted on the mechanism housing (8), a short leg (13) and a long leg (14).

7. The dishwasher according to claim 5, characterized in that the short leg (13) and the long leg (14) are spaced at an angle of 50° 160°.

8. The dishwasher according to any of the preceding claims, characterized in that the short leg (13) of the two-leg lever bears with its end (22) on the longitudinal push shaft (10) of the linear actuator and forms a swivel connection therewith.

9. The dishwasher according to any of the preceding claims, characterized in that the long leg (14) of the two-leg lever is provided at its free end (17) with a guide groove (18) to receive a plug (19) arranged at a first end (20) of the push bar, theguide groove (18) and the plug (19) forming a swivel connection between the long leg (14) and the push bar (12).

10. The dishwasher according to claim 9, characterized in that the two-leg lever (11) is made of plastic materials, such as polyoxymethylenes.

11. The dishwasher according to claim 9, characterized in that the two-leg lever (11) is made of an iron or aluminium based metal material.

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