[0001] The present invention relates, in a general aspect thereof, to a household washing
appliance, such as a washing machine, a washing/drying machine, a dishwasher or the
like, equipped with means for steam generation.
[0002] Before proceeding further it should be pointed out that, although in the following
description and in the appended claims reference will be made mainly to a washing
machine as a household appliance according to the invention, this should not however
be understood as a limiting factor, since the description will also apply to the other
above-mentioned household washing appliances, with possible slight adaptations just
in case.
[0003] As is known, increasing importance is being given in modern household appliances
to the use of steam during some steps of the operating cycle; for example, this is
the case of washing machines, which include a laundry hygienization cycle that uses
a jet of steam, which may be sprayed starting from relatively low temperatures (approx.
30 °C). Machines also exist which include entire laundry washing cycles that utilize
steam instead of water; usually these cycles are intended for delicate items, and
are characterized in that they remove wrinkles from fabrics, caused by the laundry
spinning or drying operations.
[0004] For this reason, steam is also used in clothes dryers and washing/drying machines.
[0005] In general, in the above-mentioned household appliances steam is produced by a suitable
generator; the latter essentially comprises a water collection tank, which is heated
by a resistor arranged inside (or outside) the tank itself.
[0006] The generator is in fluidic communication with the wash chamber or tub, so that steam
can be supplied into the latter; to this end, many solutions are known for putting
the generator in communication with the wash chamber, depending on the type of washing
appliance, on the size of the appliance itself and/or the size of the generator, etc.
Thus, for example, there are cases where the generator is directly housed in the tub
and essentially consists of a water collection well, wherein water is heated by the
resistor; the well may be located either at the bottom or at the rear of the tub.
[0007] Some examples of implementation of this type of solution are described in European
patent application
EP 2 604 738.
[0008] According to other possible solutions, the generator is arranged outside the wash
chamber and put in communication therewith by means of a steam supply collector or
duct; in these cases, the generator usually comprises a vessel connected to the wash
chamber, as described in European patent applications published under reference numbers
EP 2 230 348 and
EP 2 578 735.
[0009] Regardless of the type of solution adopted, it must be pointed out that in household
washing appliances the steam generator only works for a short time fraction of the
operating cycle; in fact, the steps using water in a washing machine are still prevalent,
since those using steam are only useful in some particular and limited circumstances,
like those described above for hygienizing and removing wrinkles from washed laundry.
[0010] It follows that the increased complexity, and hence higher costs, of the household
appliance, caused by the presence of steam generating means, are not always compensated
for by the advantages that can be obtained from the use of steam.
[0011] A technical problem must still be solved in this respect, i.e. to increase the performance
of the above-described household washing appliances known in the art, so as to better
exploit the steam generating means with which they are equipped.
[0012] The idea that solves this problem is to use the steam generating means of the household
washing appliance also for other purposes; in particular, the idea is to use the steam
produced by the household washing appliance also for external use, in addition to
internal use.
[0013] The features of the invention will be specifically set out in the claims appended
to this description; such features and the effects thereof will become more apparent
from the following description of a possible embodiment of the invention shown in
the annexed drawings, wherein:
- Fig. 1 is a schematic representation of a washing machine according to the invention;
- Fig. 2 is a schematic representation of the washing machine of Fig. 1 together with
the means that generate steam also available for external use.
[0014] It must be pointed out that the drawings and this description only consider those
elements which are necessary or useful for understanding the invention, whereas reference
should be made to what is well known in the art for further details. Therefore, in
light of this foreword, in the above-listed drawings reference numeral 1 designates
as a whole a washing machine according to the invention, which comprises an external
cabinet structure 2, containing a wash chamber or tub 3 that houses a drum 4 adapted
to contain the laundry to be washed (not shown in the drawing). The drum 4 can rotate
about a substantially horizontal axis, in particular by means of a motor 5 and the
associated transmission means 6, which in this case consists of a belt.
[0015] It is nevertheless worth mentioning that, for the purposes of the present invention,
the drum 3 may also be of the type that rotates about a substantially vertical axis.
[0016] The washing machine 1 comprises means for supplying wash liquid from the water mains
to the tub 3, which comprise at least one valve 8 and an inlet duct 9 extending from
the valve 8 to the wash tub 3.
[0017] The wash liquid is then drained from the washing machine 1 through draining means
for draining the tub 3, which include a pump 10 and a drain duct 11 leading out of
the machine.
[0018] The washing machine is also provided with steam generating means, more visible in
Figure 2, wherein reference numeral 15 designates a steam generator; the latter is
housed outside the tub 3 and comprises a vessel that houses a heating resistor 15'
(drawn with a dashed line because it is per se known).
[0019] Upstream, the steam generator 15 is connected to the water supply mains by means
of a duct 16 extending from the valve 8, which in this case is a three-way electrovalve;
downstream, the steam generator 15 is connected to the wash chamber 3 and to an external
steam socket 18, respectively, by means of ducts 17, 19.
[0020] Advantageously, along these ducts valves 20 and 21 are provided; the latter, just
like the electrovalve 8, is controlled by a control mainboard 24, which adjusts the
general operation of the washing machine in accordance with the various programs contained
therein.
[0021] Also the steam generator 15, which includes the heating resistor, is operationally
connected to the general electronic control board 24, whereas the output valve 21
and the external steam socket 18 are connected to a control panel 25 of the washing
machine for external steam distribution. The control panel 25 has a user interface
that comprises, for example, push-buttons or knobs, indicator lights or a display,
which interface allows adjusting the steam flow, as will be described below.
[0022] In accordance with the embodiment shown in the drawings, the washing machine comprises
also an essence diffuser 26 connected to the steam duct 19; the diffuser allows diffusing
the essences contained therein into the steam flow.
[0023] As far as the laundry wash cycles are concerned, the washing machine 1 operates as
known in the art; therefore, there will be steps in which detergents will be added,
rinse steps and or water change steps, spin steps, and steps in which steam will be
introduced into the wash chamber 3.
[0024] This operation of the washing machine is controlled by the general board 24, which
stores the various programs that can be chosen by the user through an interface like
the one mentioned above.
[0025] For further details about washing machines including steps or entire cycles using
steam, reference should be made to the known technical literature.
[0026] It only needs to be pointed out herein that in the washing machine 1, when steam
is to be supplied into the wash chamber 3, the valve 21 associated with the duct 19
of the external steam socket 18 is closed: in this manner, all the steam produced
by the generator 15 will be directed into the wash chamber 3.
[0027] In addition to this, the washing machine 1 can distribute steam for external use;
for this purpose, the operation of the washing machine is switched, and all or a part
of the steam produced by the generator will no longer be delivered into the wash chamber
3, but will be conveyed towards the external steam socket 18.
[0028] The latter is a male or female connector, per se known, to be engaged with matching
connectors of connection hoses of household appliances that utilize steam to operate.
[0029] Figure 2 schematically shows an iron 30, a brush 31 for wrinkle removal, a hair straightener
32, a household appliance 33 for cleaning floors, tiles and other surfaces in general.
[0030] Of course, these are just some of the appliances that may be used together with the
washing machine of the invention.
[0031] When a user wants to use one of these appliances, he/she will connect it to the steam
socket 18 of the washing machine; for this purpose, each one of these appliances is
equipped with a hose (only a portion of which is shown in Figure 2) ending with a
plug to be coupled to the socket 18.
[0032] Afterwards, the user will start the steam generator from the control panel 25 and
its user interface; the control panel 25 will then command the valve 21 to open and,
at least for a preset time period, the valves 8 and 20 to close.
[0033] In this way, the steam generator 15 will be able to produce steam until a pressure
suitable for the desired application will be achieved.
[0034] In fact, the steam pressure must be such as to reach the appliance 30-33 connected
to the washing machine and provide a jet with a steam flow rate which is appropriate
for the intended purpose. Preferably, the steam flow rate and pressure can be adjusted
and set by the user from the control panel 25.
[0035] Thus, for example, a certain steam flow rate can be set for ironing laundry with
the iron 30, whereas for cleaning floors, tiles and other surfaces it will be advisable
to use a different flow rate and a steam jet with higher pressure. Similar considerations
apply to the brush 31 for wrinkle removal or to the hair straightener 32, or to any
other steam appliance connected to the washing machine.
[0036] In this frame, it should be noted that steam pressure variations can be obtained
in the household appliance of the invention thanks to the fact that the steam circuit,
including the generator 15, can be pressurized for external use. In fact, by closing
the valve 20 that delivers steam into the wash chamber 3, the steam output valve 21
and the mains water intake valve 8, the generator 15 will be isolated from the external
environment at atmospheric pressure.
[0037] Therefore, when heat is supplied to the water contained in the generator by means
of the electric resistor 15', the pressure of the produced steam will increase accordingly,
since the generator 15 will have been isolated from the outside environment, thus
de facto behaving as a pressurized vessel.
[0038] Of course, the pressure value reached by the steam will still be limited to a few
tens of millibars, and will be maintained for short time intervals; the heating resistor
15' will provide the heat necessary for generating the steam flow rate required by
the user.
[0039] Therefore, it preferably features an on-off operation, allowing the generation of
a certain quantity of steam, which will accumulate into the generator 15 at a preset
pressure level; when this level is reached, the resistor 15' will be turned off by
the control panel 25.
[0040] When steam is required for external use, e.g. for the iron, the output valve 21 will
open, thereby allowing the steam to flow towards the socket 18, to which the hose
of the appliance 30-33 in use is connected.
[0041] In this context, it must be pointed out that the output valve 21 preferably also
performs the function of adjusting the steam output pressure, adapting it to the requested
application; to this end, the valve 21 is configured as or associated with a pressure
reducer, as known in the art.
[0042] It is clear that, as the steam is used by the user, the pressure in the generator
15 will decrease; therefore, in this condition the resistor 15' will be turned on
again, thereby providing the heat necessary for obtaining again the steam temperature
and pressure conditions required by the application.
[0043] For this purpose, the washing machine 1 is equipped with means for detecting the
temperature and the pressure of the steam; such means are preferably thermocouples
and pressure sensors, connected to the control panel 25 that controls the operation
of the generator 15, as previously explained.
[0044] The diffuser 26 allows diffusing substances contained therein into the steam flow
being conveyed towards the socket 18; the substances, which as aforesaid may be essence-based
liquids or disinfectants or the like, are drawn into the steam flow by Venturi effect,
and are conveyed into the appliance 30-33 connected to the socket 18.
[0045] From the above description it can be easily understood how the washing machine 1
considered herein can solve the technical problem addressed by the invention.
[0046] In fact, as already explained, the steam generator 15 is now used for producing steam
not only for the operating cycles of the washing machine, but also for external applications.
[0047] In this way, it can be exploited also when the washing machine 1 is not in use for
washing laundry: therefore, the washing machine is enriched with new functions, de
facto becoming a new household washing appliance also useful for other household jobs.
[0048] In addition to the example taken into account herein, further variants of the invention
are of course possible. As a matter of fact, although this example represents a simple
embodiment of the invention, more complex variants can be implemented which may, for
example, include a larger number of steam socket 18 than the only one available in
the case shown in the drawings.
[0049] In such a case, there will also be multiple steam ducts connected to the generator
15, or there will be multiple steam generators.
[0050] This latter solution allows, among other things, independent supply of steam to both
the wash chamber 3 and the external socket 18, so that external appliances 30-33 can
also be used when the washing machine is in operation: for example, there may be two
(or more) steam generators 15 like the one described above, arranged in parallel and
connected to both the wash chamber 3 and one or more external steam socket 18.
[0051] Of course, in all of these variants also the control board 24 of the washing machine
and the control panel 25 of the steam generator(s) 15 will be different from those
schematically described herein with reference to the example taken into consideration.
[0052] All of these variants will still fall within the scope of the following claims.
1. Household washing appliance, comprising a washing chamber (3) in which a load to be
washed is to be arranged, means (8, 9) for supplying water from the external distribution
mains to the wash chamber (3), steam generating means (15) that can be put in fluid
communication with the washing chamber in order to convey steam thereinto, characterized in that the steam generating means (15) can be put in fluid communication with the outside
environment, so that the steam can also be used outside the household washing appliance.
2. Household appliance according to claim 1, wherein the steam generating means (15)
can be put in fluid communication with the means (8, 9) for supplying water to the
washing chamber (3), in order to convey water towards the steam generating means (15).
3. Household appliance according to claims 1 or 2, comprising steam intercepting means,
which are active between the steam generating means (15) and, respectively, the washing
chamber (3) and the outside environment, so as to isolate the generating means (15)
from the outside environment and obtain steam at a higher pressure than atmospheric
pressure.
4. Household appliance according to any one of the preceding claims, comprising a steam
socket (18) in fluid communication with the steam generating means (18), for connection
to an appliance (30, 31, 32, 33) using the steam generated by the steam generating
means (15).
5. Household appliance according to any one of the preceding claims, comprising means
(26) for diffusing substances into the steam.
6. Household appliance according to any one of the preceding claims, wherein the means
for supplying mains water to the steam generator (15) comprise a three-way valve.
7. Household appliance according to any one of the preceding claims, comprising means
(25) for controlling the steam generator (15) having a user interface, thus allowing
a user to set the operation of the steam generator (15) for the use of an appliance
(30-33) to be connected to the steam socket (18).