Subject of invention
[0001] The subject of the invention is a front-load household appliance, more particularly
a washer, dryer or washer-dryer, the housing of which comprises a cover panel.
Prior art
[0002] A front-load household appliance, more particularly a washer, dryer or washer-dryer,
has a housing formed of side walls and a cover panel. The housing of such an appliance
is preferably made of metal, more particularly of sheet metal, which is surface-treated
for both corrosion protection and aesthetic appearance. The housing of a household
appliance is subject to high vibration due to specific operation of the household
appliance and must meet high stiffness requirements. Stiffness is achieved by selecting
an appropriate material type and/or material thickness and/or an appropriate geometry
of housing components. As the economic aspect is very important for general-purpose
products, the tendency is to make the material as economically advantageous as possible,
while at the same time minimizing the quantity/thickness of the material. If side
walls of a household appliance are made using thin sheet metal, higher stiffness is
achieved by forming the material in such a way that certain geometric shapes are imprinted.
The material's stiffness is increased due to plastic forming. An increased stiffness
of the housing material results in an increased own frequency of the housing, which
considerably reduces a possibility of resonance occurring during the operation of
the household appliance.
[0003] A household appliance cover panel may be fabricated of a thin sheet metal like the
rest of the housing, but may also be fabricated of non-metallic material having sufficient
stiffness. In particular, the cover panel of a washer or washer-dryer is subject to
high vibration loads during operation, especially when a centrifuge is running. If
another appliance is positioned on top of a household appliance, for instance a dryer
positioned on top of a washer, such a cover panel is even more exposed to high static
loads. Due to the low stiffness of the cover panel in vertical direction and the unsupported
large central part of the cover panel, large amplitude oscillations can occur in the
cover panel, causing additional noise and potentially permanent deformation of the
cover panel. Noise can be reduced by sound insulation arranged on the underside of
the cover panel or by selecting a thicker sheet metal or by making geometric imprints.
While a thicker sheet metal does increase the stiffness, the increase in weight is
not sufficient to achieve the desired impact in terms of increasing its own frequency.
In addition, an increased weight is undesirable due to higher material costs. Geometrical
imprints in the sheet metal and thus in the cover panel increase the stiffness and
also the own frequency of the cover panel, whereby the cover panel loses its property
of a flat surface required by users. Even more, the geometric imprints also impact
the appearance of a household appliance. The indicated solutions fail to solve the
problem of freely oscillating large surfaces.
[0004] A freely oscillating surface of a cover panel can be reduced by arranging at least
one support element on the underside of the cover panel. The problem encountered in
positioning such a support element is its placement and attachment. A support element
must be fixed to the cover panel, otherwise it would move around in a room or with
respect to the cover panel due to high vibration during the operation of a household
appliance. The function of a support element would therefore be lost and the element
might cause even additional noise. Attaching a support element to the underside of
the cover panel reduces the free surface of the oscillating cover panel. A support
element may be attached in many different ways. However, conventional ways such as
screwing, riveting, welding and gluing are less suitable due to aesthetic and economic
reasons.
Technical problem
[0005] The technical problem is to configure a household appliance having a housing, such
as a washer, dryer or washer-dryer, the cover panel of which will eliminate the above-mentioned
drawbacks and will have sufficient stiffness so that the vibrations generated by the
operation of a household appliance will not be transferred to the cover panel and
will not be further amplified in the form of cover panel oscillations, wherein the
increase in the stiffness of the cover panel will not affect the external appearance
of the cover panel and hence the household appliance.
Solution to the technical problem
[0006] The relative expressions such as front, rear, upper, lower, etc. are herein defined
from the perspective of the household appliance user, when the appliance is in its
functional state.
[0007] The technical problem is solved by a household appliance having a housing, such as
a washer, dryer or washer-dryer, which comprises a cover panel, the main characteristics
of which are defined in the first independent claim.
[0008] A household appliance, more particularly a front-load washer, dryer or washer-dryer,
has a housing that comprises a front wall, a rear wall, two lateral walls and a cover
panel with an underside, the cover panel being configured as a panel with at least
two downward oriented edge lateral walls formed as vertical flaps, and optionally
with a rear edge wall formed as a vertical flap, and/or a front edge wall formed as
a vertical flap, the two opposite edge walls formed as vertical flaps, preferably
lateral edge walls, each having a horizontal flap projecting into the interior of
the cover panel, the cover panel comprising at least one support arranged at a clearance
from the underside of the cover panel, extending between the two vertical flaps and
abutting with a respective free end on a complementary horizontal flap, a respective
horizontal flap comprising at least one stop that interacts with a complementary formed
respective free end of the beam support to prevent sliding of the beam support, more
particularly its free end along the horizontal flap; and an insulation material layer
arranged at a clearance between the support and the underside of the cover panel.
The stop is configured as a protrusion or a recess. A stop in the form of a protrusion
is configured as a positive protrusion projecting from a horizontal flap in a direction
away from the floor, or as a negative protrusion projecting from a horizontal flap
towards the floor. The number of stops on a respective horizontal flap is at least
equal to the number of supports beams or greater. The support is configured as a support
of a conventional shape, a support in a form of quadrangular profile beam, T- profile,
U- beam, I- beam or of any other shape. The cover panel of the invention, which is
configured substantially as a flat panel, is supported by at least one, preferably
more than one support arranged beneath the underside of the cover panel.
[0009] Each support reduces the free surface of the cover panel, which contributes to higher
stiffness of the cover panel and hence to reduced oscillations of large amplitudes.
As a result, the noise and permanent deformations of the cover panel are reduced as
well.
[0010] Both the cover panel and the support are made of a metallic or plastic material,
the material of the support having sufficient stiffness to provide adequate support
to the cover panel. To prevent the support from creating unwanted visual deformations
on the cover panel, the support is spaced apart from the cover panel and an insulation
material layer is arranged between them to prevent visual deformations of the cover
panel, while simultaneously fixing the support on each horizontal flap. The thickness
of the insulation material layer is such that the layer exerts an equal vertical force
on the top face of each built-in support and on the opposite face of the cover panel.
The vertical force is identical to, preferably higher than the vibration forces acting
on the support during the operation of a household appliance. The insulation material
layer is arranged at least in the area of a respective support, it may also be arranged
over the entire underside of the cover panel. At the same time, the insulation material
layer prevents the transfer of vibrations from the support to the cover panel, herewith
preventing additional noise. The insulation material layer can also be arranged over
the entire underside of the cover panel, which still additionally contributes to noise
reduction of the household appliance during its operation. A further advantage of
the insulation material layer thus arranged is that no fastening is required since
it is fixed to the underside of the cover panel by a respective support.
[0011] A household appliance having a housing that comprises a cover panel of the invention
will be described hereinbelow in more detail by way of a non-limiting embodiment and
drawings representing in
Fig. 1 housing of a household appliance, front view
Fig. 2 washer cover panel with two beam supports, view from below
[0012] A front-load household appliance 1 has a housing 2 comprising a front wall 3, a rear
wall 4, lateral walls 5, 6 and a cover panel 7. The cover panel 7 is arranged on the
upper portion of the housing 2 and closes the latter from the upper side. The cover
panel 7 is formed as a panel with at least two downward oriented edge walls formed
as vertical flaps, i. e. two lateral edge walls formed as vertical flaps and optionally
a rear edge wall and/or a front edge wall formed as vertical flap, depending on the
housing of a household appliance. In the embodiment, the cover panel 7 is formed as
a panel with downward oriented three edge walls formed as vertical flaps: two lateral
vertical flaps 8, 9 and a rear vertical flap 10. Two opposite lateral vertical flaps
8, 9 are each provided with a horizontal flap 12, 13 projecting into the interior
of the cover panel 7. The cover panel 7 is fastened to the housing 2 of a household
appliance 1 by way of a plug/recess clip-on system (not subject of the invention)
arranged on the horizontal flaps 12, 13 and the complementary walls of the housing
2, preferably the lateral walls 5, 6. As there is a risk of the cover panel 7 becoming
disengaged from the clip-on system due to vibration, the cover panel 7 is additionally
screw-fastened to the rear edge wall 10 to the rear wall 4 of the housing.
[0013] The cover panel 7 comprises at least one support 14 arranged at a clearance from
an underside 15 of the cover panel, extending between the two lateral vertical flaps
8, 9 and abutting with a respective free end 16, 17 on the complementary horizontal
flap 12, 13. The support 14 is configured as a support of a conventional shape, such
as a quadrangular beam, T-beam, U-beam, I-beam or of any other shape. In the embodiment,
the support is configured as a U-beam. The support 14 is made of a metallic material,
such as ferrous alloys or light metals, or a non-metallic material, such as a plastic
material, meeting requirements regarding material stiffness, so that it can resist
loads without getting plastically deformed.
[0014] Each horizontal flap 12, 13 comprises at least one or more stops 18. The stop 18
may be configured as a protrusion or a recess co-operating with a complementary shaped
respective free end of the support 14 to prevent sliding of the support 14, more precisely
its free end 16, 17, along the horizontal flap 12, 13. The number of stops 18 on each
horizontal flap 12, 13 is preferably equal to the number of supports beams 14, but
may also be higher. The stop 18 configured as a positive protrusion projects from
the horizontal flap 12, 13 towards the support 14, i.e. away from the ground. The
stop 18 configured as a negative protrusion projects from the horizontal flap 12,
13 away from the support 14, i.e. towards the ground. The stop 18 configured as a
protrusion or recess may be produced during the process of shaping the horizontal
flap 12, 13. Depending on the manufacturing process of the cover panel 7 and the horizontal
flap 12, 13, the stop 18 may also be made by other technological processes, e.g. by
a cutting, punching or bending process.
[0015] The support 14 acts on the underside 15 of the cover panel through an insulation
material layer 19 which is arranged at least in part between a top face 11 of the
support 14 and the opposite underside 15 of the cover panel. In the embodiment, this
is achieved in a way that the thickness of each insulation material layer 19, before
being built-in, is larger than the clearance between the top face 11 of each support
and the opposing underside 15 of the cover panel in the assembled state. Thus, in
the assembled state, the insulation material layer 19 gets compressed in the area
between the two faces 11, 15 or elastically and partially plastically deformed, i.e.
the insulation material layer 19 exerts an identical vertical force on each of said
faces 11, 15. As a result, it acts as a limiter of the vertical movement of the support
14 and fixes it in the vertical direction. At the same time, the support 14 fixes
the insulation material layer 19 to the underside 15 of the cover panel. The insulation
material layer 19 also dampens vibrations transferred from the support 14 to the cover
7. The ratio between the thickness of the insulation material layer 19 and said clearance
can be roughly defined by the elastic modulus value of the insulation material. At
lower elastic modulus values, the ratio should be higher. The values of said ratio,
the shape of the support and the shape of the insulation panels can be defined using
known engineering approaches, such as use of modern computer tools, experimental work,
etc., depending on specific requirements, such as household appliance type, vibration
generation, etc.
[0016] The insulation material layer 19 is arranged at least in the area of a respective
support 14. The insulation material layer 19 may be arranged over the entire underside
15 of the cover panel, which reduces the noise due to vibrations of the household
appliance during operation.
[0017] The housing 2 is preferably made of sheet metal. The cover panel 7 closing the housing
2 is made of a metallic material, such as steel sheet metal or light sheet metal,
or a non-metallic material, such as a plastic material, meeting requirements regarding
material stiffness, so that it can resist loads without getting plastically deformed.
1. A front-load household appliance (1), more particularly a washer, dryer or washer-dryer,
has a housing (2) that comprises a front wall (3), a rear wall (4), lateral walls
(5, 6) and a cover panel (7) with an underside (15), the cover panel (7) being configured
as a panel with at least two downward oriented edge lateral walls (8, 9) formed as
vertical flaps, and optionally with a rear edge wall (10) formed as a vertical flap
and/or a front edge wall formed as a vertical flap, the two opposite edge walls formed
as vertical flaps, preferably lateral edge walls formed as vertical flaps (8, 9),
each having a horizontal flap (12, 13) projecting into the interior of the cover panel
(7),
characterized in that the cover panel (7) comprises
at least one support (14) arranged at a clearance from an underside (15) of the cover
panel, extending between the two vertical flaps (8, 9) and abutting with a respective
free end (16, 17) on the complementary horizontal flap (12, 13), each horizontal flap
(12, 13) comprising at least one stop (18) co-operating with a complementary shaped
respective free end (16, 17) of the support (14) to prevent sliding of the support
(14), more precisely its free end (16, 17), along the horizontal flap (12, 13),
an insulation material layer (19) arranged at a clearance between the support (14)
and the underside (15) of the cover panel.
2. The household appliance according to claim 1, characterized in that the stop (18) is configured as a protrusion or/and a recess.
3. The household appliance according to any preceding claim, characterized in that the stop (18) in the form of a protrusion is configured as a positive protrusion
projecting from the horizontal flap (12, 13) in a direction away from the floor, or
as a negative protrusion projecting from the horizontal flap (12, 13) towards the
floor.
4. The household appliance according to any preceding claim, characterized in that the number of stops (18) on each horizontal flap (12, 13) is at least equal to the
number of supports beams (14), but may also be higher.
5. The household appliance according to any preceding claim, characterized in that the thickness of the insulation material layer (19), before being built-in, is larger
than the clearance between a top face (11) of each built-in support (14) and the opposing
underside (15) of the cover panel (7).
6. The household appliance according to any preceding claim, characterized in that the thickness of the insulation material layer (19) is such that in the built-in
state it acts with an identical vertical force on the top face (11) of each built-in
support (14) and the opposing underside (15) of the cover panel (7).
7. The household appliance according to any preceding claim, characterized in that the insulation material layer (19) is arranged at least in the area of a respective
support (14).
8. The household appliance according to any preceding claim, characterized in that the insulation material layer (19) is arranged over the entire underside (15) of
the cover panel (7).
9. The household appliance according to any preceding claim, characterized in that the support (14) is configured as a support of a conventional shape, in a shape of
a quadrangular beam, T-beam, U-beam, I-beam or of any other shape.
10. The household appliance according to any preceding claim, characterized in that the support (14) is made of a metallic material, such as ferrous alloys or light
metals, or a non-metallic material, such as a plastic material, meeting requirements
regarding material stiffness, so that it can resist loads without getting plastically
deformed.
11. The household appliance according to any preceding claim, characterized in that the cover panel (7) is made of a metallic material or a plastic material.