EP3089645B1

EP3089645B1 - A door assembly for a dishwashing machine, and dishwashing machine

Info

Publication number: EP3089645B1
Application number: EP14830669.9A
Authority: EP
Inventors: Silvio Corrias; Marco PISTARINO; Diego ARVEDA
Original assignee: Whirlpool EMEA SpA
Current assignee: Whirlpool EMEA SpA
Priority date: 2013-12-30
Filing date: 2014-12-16
Publication date: 2017-08-16
Anticipated expiration: 2034-12-16
Also published as: WO2015101865A1; EP3089645A1; ITTO20131080A1

Description

[TECHNICAL FIELD]

The present invention refers to a door assembly for a dishwashing machine, and related dishwashing machine preferably of a "freestanding" type.

[PRIOR ART]

Current dishwashing machines comprise a front door for loading dishes to wash; said door typically comprise hinged connection means on the door's lower side connecting said door to its articulation, and a handle on its upper side. Known dishwashers' doors, therefore, during opening and closing are subjected to flexion stress induced by the force that is applied by the user opening or closing said door, and increased by possible door misalignment which leads to strong stress being locally exerted on mechanical connection elements.
Dishwashers' doors require, therefore, enough mechanical stiffness to withstand said external stresses, especially when being opened and closed. At the same time, dishwashers' doors must be lightweight, so as to be easy to handle for users during opening and closing.
Such requirements are, therefore, in contrast with one another: known dishwashers' doors can turn out to be excessively heavy, though stiff, thus causing difficult, laborious operation by users; other known dishwashers' doors can be lightweight but poorly stiff, thus possibly leading to their breaking.
Prior art document US2010/0180916A1 discloses a door assembly for a dishwashing machine, wherein a panel of sound absorbing material (such as expanded polystyrene) is placed. The panel includes a plurality of convex and concave structures organised in a regular array and spatially arranged to be alternating with one another. A plurality of protrusions extend from a surface of the panel to allow the panel to be attached to a supporting surface.

[OBJECTS AND SUMMARY OF THE INVENTION]

An object of the present invention is to provide a door assembly for a dishwashing machine that solves some of the problems affecting prior art.
In particular, it is an object of the present invention to provide a door assembly for a dishwashing machine that is stiff and that enables to realise a door with enhanced robustness.
It is another object of the present invention to provide a door assembly for a dishwashing machine that can withstand the stress applied to the door during opening and closing for the entire product's useful life.
In particular, an object of the present invention is to achieve a door assembly that stands out amongst known technical solutions for its apparent higher resistance to torsion stress tending to create an angle between the plane of the door assembly and the plane of the aperture to be closed by said door assembly (said angle being an unwanted feature as it causes a twist of the door assembly whereby one of the two lateral edges becomes closer to the abovementioned aperture than its contralateral edge).
Furthermore, it is an object of the present invention to provide a door assembly for a dishwashing machine that is lightweight, and allows to realise a door whose opening by users is performed more easily.
Lastly, it is an object of the present invention to provide a door assembly for a dishwashing machine that is easy and quick to build and assemble.
These and other objects are achieved by means of a door assembly for a dishwashing machine and related dishwashing machine, according to the claims appended hereto forming an integral part of this description.
An idea underlying the present invention is to provide a door assembly for a dishwashing machine comprising: a door panel adapted to face outwards from the dishwashing machine; a door back panel adapted to face towards the inside of the dishwashing machine; wherein said door panel and door back panel are mutually adapted to be coupled together to form a shell-like structure and further comprising: a stiffening panel made of foam material inserted in the shell-like structure; the door assembly comprises at least one area of mechanical interference between the stiffening panel and the door back panel.
An advantageous embodiment of the door assembly comprises a plurality of interference areas between the stiffening panel and the door back panel and/or the door panel and/or the connection means (106), typically hinges, that connect the door assembly (101) to the dishwashing machine's structure. This solution allows to realise a door assembly for a dishwashing machine that is stiffer and better suited to withstand the stress applied to the door during its opening and closing.
Furthermore, the use of a foam material stiffening panel enables to realise a door assembly for a dishwashing machine that is lightweight, so that its door can be more comfortably opened by users.
The door assembly according to said solution also comprises a reduced number of components, that can be easily realised and assembled, thus providing further advantages to its industrial scale manufacturing.
Further particular and advantageous features will become more apparent from the detailed description following hereunder, as well as from the claims relating thereto.

[BRIEF DESCRIPTION OF THE DRAWINGS]

Some examples of preferred and advantageous embodiments are hereby described by way of example and not by way of limitation, with reference to the figures attached, where:

Figure 1 is an exploded view of an embodiment of the door assembly for a dishwashing machine according to the present invention.
Figure 2 shows in more details the stiffening panel of an embodiment of the present invention.
Figure 3 provides a front view (a) of the door assembly of Figure 1 from the inside of the dishwashing machine, and a couple of cross-sections (b) and (c) of the door assembly of Figure 1, in assembled state.

The Figures show different aspects and embodiments of the present invention and, where appropriate, structures, components, materials and/or similar elements in different figures are indicated with the same reference numbers.

[DETAILED DESCRIPTION OF THE INVENTION]

Figure 1 shows an embodiment of the door assembly 101 for a dishwashing machine. Said door assembly 101 is preferably realised for a dishwashing machine of the "freestanding" type, that is to say comprising a door on which no further finishing coverage is applied to match with kitchen cabinetry. Indeed, said "freestanding" dishwashers feature doors that are less stiff due to no finishing panel being applied onto them, and they can, therefore, benefit more from the advantages provided by the present invention. However, the present invention is also applicable to built-in dishwashing machines.
The door assembly 101 comprises a door panel 102 adapted to face outwards from the dishwashing machine, and a door back panel 103 adapted to face towards the inside of the dishwashing machine.
Said door panel 102 and door back panel 103 are mutually adapted to be coupled together to form the shell-like structure shown in its assembled configuration in Figure 3.
In a preferred embodiment the door back panel 103 is made
of sheet metal, preferably having a thickness of approximately 0.35 mm.
In a preferred embodiment the door panel 102 is made of sheet metal, preferably having a thickness of approximately 0.6 mm.
The door assembly 101 further comprises a stiffening panel 104 made of foam material, inserted in the above-described shell-like structure. Said stiffening panel contributes to creating in the door assembly 101 at least one area of mechanical interference between the stiffening panel 104 and the door back panel 103. Indeed, said mechanical interference areas allow the door assembly to be stiffer, thanks to the addition of foam material to its structure, as said foam material replicates the shape of the elements it is adjoined to, thus abuting onto them. This way, the structure is made more rigid by giving it a monolith-like resistance, less subjected to flexion when the door is opened or closed, thus less subjected to misalignment that may be detrimental to its resistance.
The stiffening panel 104 is preferably made of sintered polystyrene foam (also known as EPS, or simply Polystyrene), and preferably obtained from moulding with no mechanical processes
like cutting or material removal. Said stiffening panel 104 has a preferred thickness ranging from 23 mm to 28 mm.
Preferably, the door assembly 101 further comprises a sound-absorbing panel 105 inserted between the door back panel 103 and the stiffening panel 104. Preferably, the sound-absorbing panel 105 is made of recycled cotton with heat-hardened binding agent, and is preferably about 18 mm thick.
Preferably, the door assembly 101 further comprises means 106 for connection to the dishwashing machine structure, comprising in particular a plurality of hinges where the stiffening panel 104 can create a further mechanical interference area. Said further interference area between the stiffening panel 104 and the connecting means 106 turns out to bring about significant advantages in that it grants the door assembly 101 remarkable stiffness and remarkable stability in particular during opening and closing.
Moreover, preferably, the door assembly 101 can further comprise gluing between at least said door panel 102 and the external surface of said stiffening panel 104, so as to reduce possible creaking noises from the stiffening panel 104.
Figure 2 shows the stiffening panel 104 in more details. The stiffening panel 104 comprises a plurality of lateral protrusions 202 and an upper protrusion 203, made respectively in the stiffening panel's lateral areas 104 or in the stiffening panel 104 upper portion, where the door handle is typically found. The door back panel 103 comprises a respective plurality of lateral profiles adapted to abut on said lateral protrusions 202, as better shown in Figure 3. It is right in the area where lateral protrusions 202 abut on the lateral protrusions of the door back panel 103, that a lateral interference area is created. Upper protrusion 203 is instead used for relieving stress laterally as well as to grant more structural rigidity to panel 104 in the area where stresses are higher (indeed, it is an area located approximately as high as the door handle on door panel 102), without implementing any other connecting function by means of interference. Said stiffening panel 104 comprises a plurality of central protrusions 204, 205, 206 adapted to abut against said door back panel 103 to create a second area of central interference with said door back panel 103.
Preferably, central protrusions are provided in a number which is equal or higher than three, yet more preferably exactly equal to three and located at the vertices of a triangle. This way, it is possible to optimally relieve the pressure generated by the areas of interference on the door back panel 103. Said central protrusions 204, 205, 206 comprise a substantially cylindrical structure. Central protrusions are at least partially hollow internally, so as to save on materials and make the stiffening panel 104 lighter.
In particular, central protrusions 205,206 further comprise a cavity adapted to allow the passage of a wire harness or a mechanical element being substantially horizontal in said door. In particular, said recesses are suitable to allow the passing of a wire harness or a pipe.
In general, said stiffening panel 104 contributes both to making the door assembly more mechanically resistant, and to keeping in place wiring harnesses and other ancillary elements that may be found in said door.
In general, mechanical interference areas contribute to eliminating backlashes between said door panel 102 and door back panel 103 in a widespread manner e.g., lateral protrusions 202 as well as in a localized manner e.g., central protrusions 204, 205 and 206.
Furthermore, mechanical interference areas, in particular at the hinges, contribute to stiffening the door during opening and closing, so that the entire door assembly undergoes less deformation, thus increasing user-friendliness and reliability.
In an advantageous embodiment, further coupling with mechanical interference can be provided between said stiffening panel 104 and said door panel 102 also in lateral areas 209 in favour of the door assembly's increased stiffness.
Figure 3 provides a front view (a) of said door assembly 101 and a couple of cross sections (b) and (c) of the door assembly shown in Figure 1, in an assembled state.
The recess that is visible in the front view (a) is preferably used to accommodate functional devices for the machines e.g., a washing liquid dispenser.
Considering the description of the present invention related to preferred and advantageous embodiments, it is apparent to the person skilled in the art that further modifications and variants of the invention are possible.
For example, the stiffening panel can be made of any suitable foam material, having a higher or lower specific weight and different mechanical features.

Claims

A door assembly (101) for a dishwashing machine, comprising:
i) a door panel (102) adapted to face outwards from the dishwashing machine;

ii) a door back panel (103) adapted to face towards the inside of the dishwashing machine, said door panel (102) and said door back panel (103) being mutually adapted to be coupled together to create a shell-like structure;

iii) a stiffening panel (104) made of foam material, inserted in said shell-like structure;

iv) at least one area of mechanical interference (202, 204, 205, 206) between said stiffening panel (104) and said door back panel (103), wherein said stiffening panel (104) comprises a plurality of lateral protrusions (202),
wherein said door back panel (103) comprises a respective plurality of lateral profiles adapted to match said lateral protrusions (202),
wherein said door assembly (101) comprises a first area of lateral interference between said lateral protrusions (202) and said lateral profiles,
wherein said stiffening panel (104) comprises a plurality of central protrusions (204, 205, 206) adapted to abut against said door back panel (103) to create a second area of central interference with said door back panel (103),
characterised in that said central protrusions (204, 205, 206) comprise a substantially cylindrical structure which is at least partially hollow internally.
A door assembly (101) according to claim 1, wherein said substantially cylindrical structure further comprises a cavity adapted to allow the passage of a wire harness or a mechanical element, said cavity being preferably substantially horizontal in said door.
A door assembly (101) according to claim 1 or 2, wherein said stiffening panel (104) is made of sintered expanded polystyrene, preferably obtained by moulding.
A door assembly according to any one of claims 1 to 3, further comprising connecting means (106), in particular hinges, adapted to connect said door assembly (101) to a dishwashing machine, wherein a further area of mechanical interference (202) is created between said stiffening panel (104) and said connecting means (106).
A door assembly according to any one of claims 1 to 4, further comprising an additional area of lateral mechanical interference (209) between said door panel (102) and said stiffening panel (104), and preferably a gluing at least between said door panel (102) and said stiffening panel (104).
A door assembly according to any one of claims 1 to 5, further comprising a sound-absorbing panel (105) inserted between said door back panel (103) and said stiffening panel (104).
A dishwashing machine comprising a door assembly (101) according to any one of claims 1 to 6.