Field of the invention
[0001] The present invention generally relates to a household appliance, in particular to
a laundry treatment appliance, especially a washing machine, dryer or combined washer
and dryer, both for domestic and professional use. More particularly, the present
invention relates to a laundry treatment appliance comprising a user interface and
a rotary user interface element which comprises a knob as well as a method of operation.
Background of the invention
[0002] Household appliances, especially laundry machines such as washing machines, dryers,
especially tumble dryers, and combined washers/dryers are known which comprise a user
interface which can, for instance, be arranged on a front panel. The user interface
typically provides several user interface elements for selecting or inputting a desired
laundry treatment program and/or related parameters for this program.
[0003] The user interface can also provide symbols, lights, displays or other indicators
which allow giving the user a feedback on the selected choices. While switches and
push knobs are often used, as a selecting device for a treatment program among a set
of available programs, a rotary user interface element such as a rotating or rotary
knob, which can also have the functionality of a push button, is often provided. By
turning the knob, the user can easily select a desired treatment routine.
[0004] The rotary user interface element or knob is one of the most important element for
operating the machine and is used very often. It is therefore of great importance
to ensure a long lifetime and also an accurate operation of this user element.
[0005] The rotary user element as the primary interface of the machine transmits the first
impression to the user of the quality and handling of the appliance. If the user encounters
a user interface element that is easy and convenient to handle and provides a constant,
steady and solid feedback, and if she or he fells a smooth passage between the several
rotational steps during the rotation of the user interface element, she or he gains
a good quality impression of the appliance. If otherwise the user interface element
has a shaky, unpredictable, or varying response, resulting for example in a rough
and variable force needed for the rotation of the user interface element, the user
projects this impression on the appliance and gets an impression of overall low quality.
Therefore, the user interface should be reliable and should not block.
[0006] Since the knob is often a primary user interface element, its frequent use can lead
to damages which make a replacement necessary. Since the knob is protruding from the
control panel, also during handling or transport, this element can be damaged and
needs to be replaced.
[0007] In common machines, the knob can be assembled from the inside / back of the control
panel, whereby the knob passes through a control panel aperture and leaves gap such
that there is not visual overlapping between knob and control panel from the machine
external side. In other embodiments of machines, the knob is assembled from the outside
/ front of the control panel which leads to a visual overlapping between the knob
and the control panel, leaving a gap under the knob.
[0008] In both cases there are mechanical constraints that prevent the removal of the knob
by pulling it by hand. In cases when the knob needs to be exchanged, for example due
to quality issues (e.g. scratches made during the assembly phase), the operator must
disassemble the control panel assembly from the machine, dissemble the electronic
subassembly from the control panel and then remove the knob. This sequence of operations
takes usually a comparatively long time to perform, increasing the risks of components
damages, due to the control panel/electronic board disassembly.
Summary of the invention
[0009] The aim of the invention is to provide a household appliance allowing a quick, a
robust and a reliable removal of the knob.
[0010] It is a further aim of the invention to provide a method for operating a household
appliance which yields a quick, a robust and a reliable knob removal.
[0011] The invention therefor relates to a household appliance, comprising a control panel
on which a user interface element is provided which comprises a knob which is associated
with a selector, whereby the knob is partially extractable from the control panel
from a first inserted position to a second extracted position in which the knob is
in a non-operating position but axially constrained by the panel for a complete disassembly
from the appliance.
[0012] The invention is based on the consideration that it is desirable to allow a quick
and convenient removal of the knob without the need of the disassembly of further
components. The knob at the same time should still make a qualitatively high and pleasant
impression. Current solutions make a rather high demand on time and working steps
for the removal of the knob.
[0013] Applicant has found that these demands can be met by designing the knob in such a
way that it can be removed in a two-step process. The knob can first be put into a
non-operating position in which it is axially constrained. There is thus not the danger
that it can be too easily removed or pulled out. In this position, the knob is accessible
for dissemble from the panel, preferably by a tool.
[0014] In the first inserted position, the knob, in its normal operating condition, is operational
and functions as a user interface element. In the second extracted position, the knob
is configured to be detachable but cannot be ditched by further pulling which would
eventually destroy the knob. Its detachment is only possible by actively, especially
by using a tool, disengaging the knob.
[0015] Preferably, especially only, in the second position, the knob is at least partially
removable from the control panel.
[0016] In a preferred embodiment, the knob comprises a knob cover element and a knob carrier
element or underknob, whereby the knob cover element is removably attached to the
knob carrier element, and whereby the knob carrier element is, especially in an axial
direction of the knob, slideably arranged at least partially behind the control panel.
This design is based on the recognition that damages occur typically on the part of
the knob protruding form the control panel. When the knob is built in the described
two-part design, the carrier element can remain behind the control panel since only
the cover element needs to be replaced. The two-part structure therefore enables a
convenient replacement without trade-offs in stability or reliability of the knob.
[0017] Advantageously, the knob cover element is fully detachable from the knob carrier
element by the user in / only in the second position. It thus can be removed and replaced
by a new cover element which can be attached / connected to the carrier element.
[0018] Preferably the knob cover element and the knob carrier element are attached to each
other by a snap connection / fastening means. This design allows a quick detachment
of these two components.
[0019] The knob carrier element preferably comprises at least one hook seat into which in
the attached configuration at least one snap hook of the knob cover element engages.
In another embodiment, the hooks are arranged on the carrier element and engage with
hook seats on the cover element.
[0020] The knob carrier element preferably comprises an external flange acting as an axial
block when the second extracted position of the knob is reached. In this way, when
the knob cover is pulled away from the control panel, a natural stop is realized indicating
a second position which is suitable for disengagement of cover and carrier elements.
[0021] This flange in the second extracted position preferably is blocked by blocking means
/ an abutting element or portion, preferably a sleeve, of the control panel. These
means, especially this sleeve is therefore arranged behind an outer surface of the
control panel and in front of / in contact of the flange of the carrier element when
fully inserted.
[0022] Advantageously the knob carrier element is slideably arranged with respect to / on
the selector.
[0023] Preferably, in the assembled position of the knob cover element and the knob carrier
element, between these two elements a, preferably radial, aperture is provided which
is configured to allow the insertion of a tool when the knob is arranged on its second
extracted position.
[0024] Preferably, said tool is configured to allow the cover element disassembly, i.e.
the removal of the cover element from the carrier element. The concrete design of
the tool can depend on the concrete attachment of these two components. For example,
it can be built as a pen- or bolt-type device for disengaging snap elements, especially
hooks.
[0025] The knob cover preferably is non-rotatable mounted on the knob carrier element. Knob
cover and knob carrier element in this way rotate together in a collinear way with
the same angular velocity, i.e. they don't change their relative orientations during
rotation. When the knob cover is turned by the user, the knob cover transmits the
same rotational movement to the carrier element.
[0026] The knob carrier element advantageously comprises means interacting with an encoder.
Preferably, the encoder is provided on an electronic board provided on the rear side
of the knob, said encoder preferably comprising a base connected to the electronic
board and a rotatable pin, the rotation of which result in a different signal used
by the machine control unit to select the program / parameter.
[0027] Preferably the material of the knob cover and/or the knob carrier element is A.B.S.
(Acrylonitrile butadiene styrene).
[0028] Advantageously, the household appliance is built as a laundry treatment machine.
Most preferably, it is built as a washer, a dryer or combined washer/dryer. It preferably
is built as a front-loading washing machine or washer / dryer.
[0029] The invention also relates to a method for operating a household appliance previously
described, with the steps of
- pulling the knob cover element away from the control panel until the knob reaches
the second extracted position;
- detaching the knob cover element from the knob carrier element.
[0030] The knob cover element is preferably attached to knob carrier element by snap elements
or hooks which in the mounted position engage in respective seats.
[0031] Preferably the tool is inserted into a, preferably radial, aperture between these
two elements which is designed to allow the insertion of a tool when the knob is arranged
on its extracted position.
[0032] Preferably the tool is inserted for disengaging connection elements located on cover
and/or carrier elements such that the cover element is not attached anymore to the
carrier element and can be disengaged and removed. For initial assembly or replacement,
the respective cover element is attached the carrier element. The cover element is
then pushed towards the control panel until cover and carrier elements reach the first
position in which the knob is operational as a user interface element.
[0033] The advantages of the invention are essentially as follows. Due to the design of
the knob which can assume two positions of which the second allows a disassembly of
the knob, it can be replaced very quickly, assuring at the same time a easier way
of knob disengagement. For its replacement, the control panel and electronic subassemblies
do not need to be removed or disassembled. Moreover, the removal of the electronic
subassembly from the control panel is made easier since the encoder's pin is not fixed
inside the knob.
Brief description of the drawings
[0034] Further features and advantages of the present invention shall become clearer from
the following detailed description of some of its preferred embodiments, made with
reference to the attached schematic drawings and given as an indication and not for
limiting purposes.
[0035] In particular, the attached drawings are included to provide a further understanding
of the invention and are incorporated in and constitute a part of this specification.
The drawings together with the description explain the principles of the invention.
In the drawings, corresponding characteristics and/or components are identified by
the same reference numbers. In these drawings:
- FIG. 1
- shows a household appliance with a knob in a preferred embodiment in a perspective
view;
- FIG. 2
- shows the household appliance according to FIG. 1 in a frontal view;
- FIG. 3
- shows a knob cover element;
- FIG. 4
- shows a knob carrier element;
- FIG. 5
- shows knob cover element and knob carrier element mounted on the control panel of
the household appliance in a first position;
- FIG. 6
- shows knob cover element and knob carrier element mounted on the control panel of
the household appliance in a second position;
[0036] In FIGs 1 and 2, a household appliance 2 is shown which is built as a front-loading
washing machine and comprises a housing or casing 6 with a preferable parallelepiped
shape, the casing 6 comprising a front wall 10, two side walls 14, a cover plate 20
and a rear wall (not shown). Front wall 10 and side walls 14 are preferably part of
a cabinet. A front door 24 is provided which can be opened for loading or unloading
laundry through an opening 28 into a washing drum. Front door 24 comprises a handle
32 for convenient opening and closing.
[0037] Advantageously a washing tub is contained within casing 6, whereby a rotatable and
perforated drum is contained by said washing tub. Both washing tub and drum have a
substantially cylindrical shape. Advantageously the tub is suspended in a floating
manner inside casing 6 by means of a number of coil springs and shock absorbers. The
drum is rotated by an electric motor (not shown), which transmits the rotating motion
of a motor shaft to the drum by a belt/pulley system. In a different embodiment of
the invention, the motor can be directly associated with the shaft of the drum. The
tub is preferable connected to casing 6 by means of an elastic bellows or gasket.
Alternatively, the laundry appliance can be a dryer (in which case the tub is not
provided) or a combined washer and dryer.
[0038] The preferred washing machine shown in FIGs 1 and 2 on a front panel 48 comprises
a drawer 30 with a front plate 34 and a handle 38 for pulling out and pushing back
the drawer 30. Drawer 30 preferably comprises at least one compartment for detergent
or washing additives. Preferably, adjacent to drawer 30, a rotatable or rotary knob
44 is arranged for selecting a laundry treatment program and/or at least one parameter
of a laundry treatment program. Knob 44 is preferably provided on a control panel
62 or user interface which can provide further indicating and/or control elements.
Knob 44 is preferably arranged on front panel 48 adjacent to drawer 30, whereby preferably
no user interface elements such as controls (buttons, dials) or indicating elements
(displays, lights) are arranged between drawer 30 and knob 44. On a panel 64 which
is part of control panel 62, user interface elements such as at least one display
and/or buttons and/or indicators can be provided. A service hatch 70 is preferably
provided on front wall 70 which preferably yields access to a filter unit.
[0039] The knob 44 shown in FIGs. 1 and 2 comprises a knob cover element 70 shown in FIG.
3 and a knob carrier element 72 shown in FIG. 4. Knob cover element 70 preferably
has a circular shape and preferably comprises at least one region 74, 76 of corrugated
surface which allow the user to conveniently operate the knob 44 by preventing that
the users fingers slide on the perimeter of the knob 44 when turning it. Cover element
70 preferably comprises a further corrugated region 78, whereby centrally in this
region 78, an indicating element 82 is arranged which protrudes from an outer perimeter
86 of cover element 70. Indicating element 82 is arranged in cover element 70 preferably
in such a way that indicating element points vertically upwards when knob 44 does
not correspond to a specific setting of an appliance parameter / program. Cover element
70 comprises a circular front surface 88 which is preferably concavely shaped (see
Figs 5 and 6).
[0040] As can be seen in FIG. 4, carrier element 72 has a circular base portion or flange
90 from which a first part 94 protrudes. From first part 94 a central part 98 and
two pins 100, 102 protrude which are arranged on opposite sides of central part 100.
Part 94 preferably comprises, preferably on opposing sides, hook seats 110, 112 into
which hooks 120, 122 of cover element 70 engage (see Figs 5 and 6).
[0041] Pins 100, 102 have two functions: to assist the positioning of cover element 70 on
carrier element and to reduce clearances. Regarding the positioning function, pins
100, 102 have different diameter and engage with / are received in two holes provided
on a backside of cover element 70 which in the mounted position faces the control
panel 62. The two holes have corresponding diameters, resulting in the fact that the
cover element 70 can only in one prescribed orientation be mounted on carrier element
72, avoiding mistakes regarding the assembly of these two components.
[0042] The pins 100, 102 additionally serve to reduce clearances between cover element 70
and carrier element 72. Since hooks 120, 122 do not eliminate all possible displacements
between elements 70 and 72, the pins 100, 102 together with the respective holes in
cover element 70 eliminate possible remaining clearances / play between these two
components. They determine the distance between these two components 70, 72 when the
pins are fully inserted in the respective holes and prevent also lateral respective
movements as well as rotational play.
[0043] In FIG. 5, knob 44 with cover element 70 and carrier element 72 is shown in a mounted
position on control panel 62. Carrier element 72 is preferably rotatable mounted on
a carrier seat element 130. The carrier seat element 130 provides an axial stop in
direction opposite to axial direction 160. In this position, the knob 44 is fully
functional. A rotatable pin 142 being part of a selector which is connected to an
electronic board of the appliance 2 is received by central opening preferably provided
on central part 98 of the carrier element 72 on its side facing control panel 62.
Snap hooks 120, 122 of cover element 70 are engaged in hook seats 110, 112 of carrier
element 72.
[0044] The encoder of appliance 2 preferably comprises a base connected to the electronic
board and a rotatable pin 142, the rotation of which result in a different signal
used by the machine control unit to select the program / parameter.
[0045] The hole in central part 98 has in the preferred embodiment shown an asymmetric cross
section throughout its depth, corresponding to the cross section of pin 142. When
in the mounted configuration pin 142 is received by opening on the central part 98,
when cover element 70 and carrier element 72 co-rotate, pin 142 is rotated. In the
second extracted position of knob 44 below described, the pin 142 is still at least
partially located in opening 98. Thus, when cover element 70 is rotated, still the
pin 142 is rotated.
[0046] In an alternative embodiment, the opening on the central part 98 can have a circular
cross section in a region facing the control board and a asymmetric cross section
in a region opposite to control board in such a way that in the first or fully inserted
position, pin 142 engages with the asymmetric part and is turned when cover element
70 is turned. In the second extracted position below described, however, pin 142 is
located in the circular region of opening 98 in such a way that a rotation of cover
element 70 and carrier element 72 does not lead to a rotation of pin 142.
[0047] In the configuration displayed, the cover element 70 and carrier element 72 are fixed
with each other both in an axial direction 160 as well as radial direction, i.e. both
elements 70, 72 rotate collinearly with each other with the same angular velocity
when the cover element 70 is turned by the user. The configuration shown in FIG. 5
is a first, fully inserted configuration of knob 44 in which the household appliance
2 is operated.
[0048] In FIG. 6, a second configuration of knob 44 is shown. Both cover element 70 as well
as carrier element 72 are translated in axial direction 160 compared to the configuration
shown in FIG. 5. The maximal stroke by which carrier element 72 can be moved in axial
direction 160 is limited by a, preferably circular, sleeve 166 of control panel 62.
At this maximal stroke a second positon of knob 44 is defined in which flange 90 touches
sleeve 166 by which further movement in axial direction 166 is blocked. In this position,
knob 44 is not functional but prepared for full detachment of the knob cover element
70. Between cover element 70 and the carrier element 72 a radial aperture 170 is formed
which is in this second position accessible by a tool. In the present configuration
shown in FIG. 6, a tool can be inserted into aperture 170 in order to disengage cover
element 70 from carrier element 72. This is achieved by disengaging snap hooks 120,
122 from seats 110, 112. Snap hooks 120, 122 and/or seats 110, 112 are built elastically
and can be preferably disengaged one after the other or simultaneously. When both
hooks 120, 122 are disengaged, cover element 70 is disengaged from carrier element
72 and can be fully removed.
[0049] The knob replacement is therefore performed as follows. In a first step, starting
from the configuration shown in FIG. 5, knob cover element 70 is pulled in axial direction
160 until a mechanical resistance is detected when movement of flange 90 is stopped
by sleeve 166. Until this position has reached, cover element 70, which is engaged
with carrier element 72, and carrier element 72 move together in axial direction 160.
[0050] When this second position is reached, the aperture 170 between cover element 70 and
carrier element 72 is accessible. A tool, preferably a screwdriver, is inserted into
aperture for disengaging hooks 120, 122 from respective hook seats 110, 112. Cover
element 70 can now be removed, leaving behind carrier element 72. The tool is suitable
for this disengagement and is preferably provided with the appliance 2 to the user.
[0051] For initial assembly and/or replacement, another cover element 70 is connected to
carrier element 72 by engaging hooks 120, 122 of cover element 70 with hook seats
110, 112 of carrier element 72. Pins 100, 102 described above engage with corresponding
holes in cover element 70 and assure a correct rotational orientation of cover element
70 and carrier element 72 with respect to each other. Also they center elements 70,
72 and reduce clearances and play. Both elements 70, 72 can be pushed towards the
control board 62 in a direction opposite to axial direction 160 until the first and
fully inserted position is reached in which carrier element 72 is seated on carrier
seat element 130.
[0052] The invention thus conceived can be subjected to numerous modifications and variants
all falling within the scope of the inventive concept.
[0053] In addition, all details can be replaced by other technically equivalent elements.
In practice, all the materials used, as well as the shapes and contingent dimensions,
may vary depending on the requirements without departing from the scope of protection
of the following claims.
1. Household appliance (2), comprising a control panel (62) on which a user interface
element is provided which comprises a knob (44) which is associated with a selector,
characterized in that
said knob (44) is partially extractable from said control panel (62) from a first
inserted position to a second extracted position in which said knob (44) is in a non-operating
position but axially constrained by said panel (62) for a complete disassembly from
said appliance (2).
2. Household appliance (2) according to claim 1, whereby in said second position, said
knob (44) is at least partially removable from said control panel (62).
3. Household appliance (2) according to claim 2, whereby said knob (44) comprises a knob
cover element (70) and a knob carrier element (72), whereby said knob cover element
(70) is removably attached to said knob carrier element (72), and whereby said knob
carrier element (72) is slideably arranged at least partially behind said control
panel (62).
4. Household appliance (2) according to claim 3, whereby said knob cover element (70)
is fully detachable from said knob carrier element (72) by the user in / only in said
second position.
5. Household appliance (2) according to claim 3 or 4, whereby said knob cover element
(70) and said knob carrier element (72) are attached to each other by a snap connection/fastening
means.
6. Household appliance (2) according to claim 5, whereby said knob carrier element (74)
comprises at least one hook seat (110, 112) into which in the attached configuration
at least one snap hook (120, 122) of said knob cover element (70) engages.
7. Household appliance (2) according to one of the claims 3 to 6, whereby said knob carrier
element (72) comprises an external flange (90) acting as an axial block when said
second extracted position of said knob (44) is reached.
8. Household appliance (2) according to claim 7, whereby said flange (70) in said second
extracted position is blocked by a blocking means (166) of said control panel (62).
9. Household appliance (2) according to one of the claims 3 to 8, whereby said knob carrier
element (72) is slideably arranged with respect to / on said selector.
10. Household appliance (2) according to one of the claims 3 to 9, whereby in the assembled
position of said knob cover element (70) and said knob carrier element (72), between
said two elements (70, 72) an aperture (170) is provided which is configured to allow
the insertion of a tool when said knob (44) is arranged on said second extracted position.
11. Household appliance (2) according to one of the claims 3 to 10, whereby said knob
cover element (70) is non-rotatable mounted on said knob carrier element (72).
12. Household appliance (2) according to one of the claims 3 to 11, whereby said knob
carrier element (72) comprises means interacting with an encoder.
13. Household appliance (2) according to one of the claims 3 to 12, whereby the material
of the knob cover and/or the knob carrier element is A.B.S. (Acrylonitrile butadiene
styrene).
14. Household appliance (2) according to one of the claims 3 to 13, which is built as
a laundry treatment machine.
15. Method for operating a household appliance (2) according to one the claims 3 to 14,
with the steps of
• pulling said knob cover element (70) away from said control panel (62) until said
knob (44) reaches said second extracted position;
• detaching said knob cover element (70) from said knob carrier element (72).