U.S. patent application number 12/849855 was filed with the patent office on 2011-02-17 for dishwasher with connection device for a plurality of water inlet lines.
This patent application is currently assigned to BSH BOSCH UND SIEMENS HAUSGERATE GMBH. Invention is credited to Christian Ertl, Markus Gram, Bernd Heisele.
Application Number | 20110036382 12/849855 |
Document ID | / |
Family ID | 43415344 |
Filed Date | 2011-02-17 |
United States Patent
Application |
20110036382 |
Kind Code |
A1 |
Ertl; Christian ; et
al. |
February 17, 2011 |
DISHWASHER WITH CONNECTION DEVICE FOR A PLURALITY OF WATER INLET
LINES
Abstract
A dishwasher having water connections and a connection device
with an output and inputs, wherein each of the inputs is connected
to a respective water connection. The connection device opens the
input whose assigned water connection supplies water and
automatically seals all remaining inputs when the input whose
assigned water connection supplies water is open.
Inventors: |
Ertl; Christian;
(Holzheim-Ellerbach, DE) ; Gram; Markus;
(Augsburg, DE) ; Heisele; Bernd; (Sontheim,
DE) |
Correspondence
Address: |
BSH HOME APPLIANCES CORPORATION;INTELLECTUAL PROPERTY DEPARTMENT
100 BOSCH BOULEVARD
NEW BERN
NC
28562
US
|
Assignee: |
BSH BOSCH UND SIEMENS HAUSGERATE
GMBH
Munich
DE
|
Family ID: |
43415344 |
Appl. No.: |
12/849855 |
Filed: |
August 4, 2010 |
Current U.S.
Class: |
134/172 |
Current CPC
Class: |
A47L 15/4217
20130101 |
Class at
Publication: |
134/172 |
International
Class: |
A47L 15/42 20060101
A47L015/42 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 17, 2009 |
DE |
10 2009 028 591.1 |
Claims
1. A dishwasher, comprising: a plurality of water connections; and
a connection device having an output and a plurality of inputs,
each of the plurality of inputs connected to a respective one of
the plurality of water connections; wherein the connection device
is structured to open an input of the plurality of inputs whose
assigned one of the plurality of water connections supplies water
and to automatically seal all remaining inputs of the plurality of
inputs when the input whose assigned water connection supplies
water is open.
2. The dishwasher of claim 1, further comprising a plurality of
water inlet lines, each water inlet line connecting a respective
one of the plurality of inputs to the respective one of the
plurality of water connections, and wherein the dishwasher is a
domestic dishwasher.
3. The dishwasher of claim 1, wherein, as a result of water
pressure of the assigned water connection that supplies water, the
connection device is structured to open the input and to seal all
the remaining inputs of the plurality of inputs.
4. The dishwasher of claim 1, wherein the connection device has
sealing means to open the input and to seal all the remaining
inputs of the plurality of inputs.
5. The dishwasher of claim 4, wherein the connection device has a
hollow main body, and wherein the sealing means is movably mounted
in an interior of the hollow main body.
6. The dishwasher of claim 5, wherein the connection device has
exactly two inputs, which connect to opposite ends of the hollow
main body.
7. The dishwasher of claim 6, wherein the output is connected to a
lateral surface of the hollow main body.
8. The dishwasher of claim 7, wherein the output is connected
essentially midway between the two inputs.
9. The dishwasher of claim 5, wherein the sealing means is a piston
which is displaceably mounted in the hollow main body.
10. The dishwasher of claim 9, wherein the sealing means is pushed
by water pressure of a water-supplying water connection toward a
first input situated opposite to a second input that is attached to
the water-supplying water connection in order to close the first
input and to open the second input.
11. The dishwasher of claim 1, wherein the plurality of water
connections are inlet valves.
12. The dishwasher of claim 11, wherein each of the inlet valves is
attached to a respective one of the plurality of inputs of the
connection device via a respective one of the plurality of water
feed lines.
13. The dishwasher of claim 12, wherein the plurality of water feed
lines are water hoses.
14. The dishwasher of claim 12, wherein the inlet valves, the water
feed lines and the connection device form a waterstop system.
Description
BACKGROUND OF THE INVENTION
[0001] The invention relates to a dishwasher, in particular a
domestic dishwasher, having a plurality of water connections.
[0002] DE 197 17 449 A1 discloses a washing machine having a warm
water supply and a cold water supply. The warm water supply
comprises a warm water valve and the cold water supply comprises a
cold water valve, these being controllable by means of a controller
of the washing machine.
BRIEF SUMMARY OF THE INVENTION
[0003] The object underlying the invention is to provide a
dishwasher, in particular a domestic dishwasher, having at least
two water connections, in particular a cold water connection and a
warm water connection, with improved water feed.
[0004] The object of the invention is achieved by means of a
dishwasher, in particular a domestic dishwasher, having a plurality
of water connections, and a connection device which has a plurality
of inputs that are attached to the water connections, in particular
via water inlet lines, and one output, and which is embodied in
such a way that it opens the input whose assigned water connection
supplies water and seals the other input or all other inputs
automatically when the relevant input is open.
[0005] It is therefore possible definitively to predetermine a
specifically assigned water inlet path into the washing compartment
of a dishwasher, in particular a domestic dishwasher, for the inlet
water from the relevant water connection. As a result of this, any
branching or cross-coupling of water into the other water
connection which is not currently open but is closed in the inflow
or inlet direction, i.e. does not carry water, in particular into
its water inlet line to the connection device, are largely
prevented. As a result of this isolation of the water connections
and in particular of their water inlet lines by means of the
inventive connection device it is therefore possible largely or
completely to prevent water from the one currently open water
connection from flowing back into in particular the water inlet
line of the other, currently closed water connection or even into
an upstream water line system, i.e. "crossover" as reverse flow.
This allows a selective water feed into the dishwasher from the
plurality of water connections, in particular via their water inlet
lines.
[0006] By means of a thus embodied inflow diverter it is therefore
advantageously ensured that water coming from the water connection
that is currently supplying water and via its assigned input of the
connection device can in particular flow only i.e. solely via the
output of the connection device and into the dishwasher. Any
overflow from the first input of the connection device, which
merges at least two water supplies, into its other input (of which
there are at least two), and any reverse flow in the direction of
the water supply of said other input, i.e. in a backflow direction
to its water connection which does not carry water, are reliably
prevented.
[0007] In particular, it is therefore possible largely to prevent
water from the water inlet line of the currently utilized water
connection from entering the water inlet line of the other,
currently unutilized water connection as a result of backflow or
overflow in the common junction part, and being stored there
temporarily in the form of an unintended filling. In the absence of
a connection device according to the invention, however, such an
unintended filling of the currently unutilized water inlet line
with water from the currently utilized water inlet line would
occur. If the currently unutilized, i.e. inactive, water connection
were to be opened, i.e. activated, subsequently, this unintended
filling would flow into the liquid circulation system of the
dishwasher first, and fresh inlet water would only flow in
afterward, i.e. at a later time. As a result of this there would be
a mixture of fresh water and the water volume of said unintended
filling in the washing compartment of the dishwasher, in particular
its sump.
[0008] However, in the case of e.g. a bithermal water connection,
i.e. if the dishwasher has both a cold water connection and a warm
water connection, the connection device embodied according to the
invention prevents the possibility of unintended filling of the
cold water inlet line with warm water and the warm water inlet line
with cold water. An unwanted mixture of warm water freshly flowing
in from the warm water connection via its warm water inlet line
into the dishwasher with cold water from an unintended filling of
the warm water inlet line, and/or conversely of cold water freshly
flowing in from the cold water connection via its cold water inlet
line into the dishwasher with warm water from an unintended filling
of the cold water inlet line, is therefore largely prevented. In
this way it is always possible to ensure that a specific required
warm water volume from the warm water connection or a defined cold
water volume from the cold water connection can be metered into the
dishwasher selectively and hence in a defined, i.e. controlled,
manner. This can be advantageous in particular if e.g. a first
partial wash cycle of a current wash cycle of a selected
dishwashing program requires a specific warm water volume at a
specific desired warm water temperature, yet a second partial wash
cycle demands a specific cold water volume at a specific desired
cold water temperature. Expressed in more general terms, the
inventive connection device therefore allows the selective supply
of currently desired water volumes from the plurality of water
connections into the dishwasher in a controlled manner.
[0009] As a result of the isolation of the plurality of water inlet
paths by means of the inventive connection device it is moreover
possible reliably to prevent any impurities in the water of the
first water connection, such as e.g. a warm water connection, from
being introduced via the water inlet line of the second water
connection, such as e.g. a cold water connection, into its upstream
water supply system, e.g. a drinking water network. This means that
it is also possible easily and reliably to satisfy requirements
relating to hygiene regulations.
[0010] The inventive dishwasher has a plurality of water
connections by means of which it can be connected to e.g. one and
the same water supply system, in particular a water network, or a
plurality of independent water supply systems and/or installations.
In particular, according to an advantageous development of the
invention, it can be beneficial for one input of the connection
device of the dishwasher to be connectable to a cold water network,
in particular a drinking water network, and another input to be
connectable to a warm water or hot water supply installation of a
building. This beneficial bithermal multiple, in particular "duo",
connection is advantageous in particular for increasing the energy
efficiency and/or drying performance of the dishwasher, since it
allows the washing-stage-specific, i.e. selective, introduction
into the dishwasher, in particular into its water circulation
cycle, preferably its sump, of cold water for the one or more
washing stages of a selected currently running dishwashing program
which require cold water or only work with cold water in each case,
and/or the washing-stage-specific (i.e. selective) introduction of
warm or heated water for the one or more washing stages of the
selected current dishwashing program which require warm or hot
water in each case. The supply of the dishwasher with warm water or
hot water from an external warm water supply installation is
advantageous in particular if its warm water or hot water is
generated exclusively, i.e. solely, or at least to some extent with
the aid of a thermal solar system.
[0011] In order now to prevent the possibility of water flowing
from one water connection into the other water connection (in
particular from the cold water connection into the warm water
connection and vice versa) as a result of line cross-coupling at
the junction point of the supply lines which lead from the at least
two water connections to the dishwasher, the inventive dishwasher
has a common connection device that on one side is attached by its
inputs to the two different water connections and on the other side
comprises an output, this being attached e.g. to a water inlet part
of the dishwasher, in such a way that water from the relevant
selected open water connection can only flow into the inventive
dishwasher in a forward direction, but cannot cross-couple in a
reverse direction to the other water connection, which is not
currently carrying water. In order, therefore, to ensure that it is
impossible for water from the relevant, i.e. current,
water-supplying water connection to enter the other water
connection or connections which are not supplying water, or even to
enter its upstream line systems, such as e.g. an external drinking
water line, the connection device is embodied so as both to open
that one of its inputs whose assigned water connection is currently
supplying water, and also to seal its other inputs automatically,
in particular as a result solely of the water pressure becoming
effective in the water-carrying input.
[0012] According to a preferred embodiment variant of the inventive
dishwasher, the automatic closure of the input or inputs whose
water connections do not currently supply water is realized by
embodying the connection device such that the relevant input opens
and the other input or inputs are sealed as a result of the water
pressure of the water connection that does supply water. The
connection device therefore functions automatically without
additional (electronic) control.
[0013] The connection device can preferably have a sealing means
which opens the relevant input and seals the other input or inputs.
This sealing means is preferably activated or set as a result of
the water pressure of the water of the water connection which is
currently supplying water.
[0014] The connection device can have a hollow main body, in the
interior of which the sealing means is movably mounted. As a result
of the movable mounting it is possible with relative ease for the
water pressure to move the sealing means and hence open the
relevant input and seal the other input or inputs. The main body
can preferably be embodied in the form of a hollow cylinder. In
particular, the main body can be embodied as a hollow circular
cylinder and in particular in the form of a straight circular
hollow cylinder.
[0015] According to a preferred embodiment variant of the inventive
dishwasher, the connection device has exactly two inputs, these
being connected to opposite ends of the main body. Consequently,
the water pressure can where necessary push the sealing means away
from the input receiving the water flow and toward the opposite
input, whereby the connection device input to which water is
applied opens automatically, solely as a result of the water
pressure, and the other input closes automatically.
[0016] The output can be connected in particular to the lateral
surface of the main body, in particular essentially midway between
the two inputs. It is then possible for the sealing means to leave
the output free with minimal impedance, thereby allowing an
unimpeded flow of water from the relevant water connection via the
connection device into the appliance interior of the inventive
dishwasher.
[0017] According to a preferred variant of the inventive
dishwasher, the sealing means is embodied as a piston which is
displaceably mounted in the main body. This can be moved with
particular ease by the water pressure, thereby increasing the
operating reliability of the inventive dishwasher.
[0018] According to a further preferred embodiment variant of the
inventive dishwasher, provision can be made for implementing the
connection device in such a way that the sealing means, which is
implemented in particular as a piston, is pushed by the water
pressure of the water-supplying water connection toward the input
situated opposite to the input that is attached to the
water-supplying water connection, in order to close this and to
open the input that is attached to the water-supplying water
connection.
[0019] The water connections of the inventive dishwasher are
preferably embodied as inlet valves or supply valves. The inlet
valves comprise e.g. magnetic valves, preferably aquastop valves,
which are opened and closed e.g. by a control device of the
inventive dishwasher, in order to control e.g. the water inlet of
the inventive dishwasher.
[0020] The inlet valves can be attached to the inputs of the
connection device via water feed lines which are embodied in
particular as water hoses. The convenience of connecting the
inventive dishwasher to the water network is increased in
particular if the water hoses are implemented to be flexible. The
water hoses can preferably run inside sleeving hoses. If one of the
water hoses leaks, for example, the corresponding sleeving hose can
capture the escaping water.
[0021] The inlet valves, the water feed lines and the connection
device can preferably form a waterstop system. This then has a
security mechanism if applicable, in order to prevent the inlet of
water if there is a fault in the water hoses in particular, e.g. by
means of the control device automatically blocking the inlet
valves.
[0022] The invention therefore provides a bithermal or duothermal
water connection where appropriate, i.e. a cold water connection
and a warm water connection at the same time, or expressed even
more generally, preferably as a multithermal water connection,
having a type of integrated non-return valve at the common junction
point or coupling region, which largely or completely blocks, i.e.
prevents, any reverse flow or "crossover", i.e. from one water
supply line to the other against its water supply direction.
[0023] In particular, the following advantageous embodiment
variants can be beneficial:
[0024] The inventive dishwasher can be utilized in particular in
conjunction with solar energy. Increasing use is being made of
solar energy for the purpose of generating warm water. Owing to the
fact that this energy is available for heating at essentially no
cost during the summer months, its use should be maximized at this
time of year. The dishwasher can utilize this free energy
efficiently, at least relatively efficiently, and largely without
compromising washing and drying performance or even with improved
washing and drying performance, if the solar energy provides a
sufficient contribution to the warm water supply of e.g. a
building, preferably a house. At the same time, however, provision
can be made for alternatively operating the appliance without
restriction using exclusively cold water if the thermal solar
system does not provide a sufficient contribution to the water
warming of a warm water supply installation, or conversely using
only warm water if there is no cold water connection available at
all, for example. In any case, irrespective of whether the
dishwasher is connected to a warm water connection and/or cold
water connection, perfect functional operation of the dishwasher
can be ensured in this way with the aid of the inventive connection
device.
[0025] In the case of a single, monothermal water connection, i.e.
only a cold water connection or only a warm water connection, for
example, the washing program control would be relatively limited. A
monoconnection to either only cold or warm water could result in
disadvantages with regard to the washing and drying performance. If
only one warm water connection were utilized exclusively, e.g. a
heat exchanger or a water pocket which is attached in a
heat-conducting manner to a side wall of the washing compartment,
would possibly only be filled with warm water, whereby a drying
result would occur that was inferior to that achieved in the case
of dishwashers having a cold water supply and appliance-internal
heating of the washing liquor. This is due to the fact that
adequate cooling of the side wall and hence the generation of an
adequate temperature gradient between the interior of the washing
compartment and the side wall using the externally attached water
pocket would in practice be no longer or only insufficiently
feasible for the perfect condensation of water vapor which would be
present in the interior of the washing compartment following a
rinsing operation that preceded the drying operation of the
currently running dishwashing program concerned.
[0026] In order that a dishwasher according to an advantageous
variant of the invention can be supplied with both cold water and
additionally or independently with warm water as required, the
dishwasher is equipped with the inventive connection device,
preferably internally, such that its two separate inputs can be
connected to at least two separately controllable water
connections, in particular having integrated waterstop valves or
so-called aquastop valves, for cold water inlet and warm water
inlet. According to the invention, one of the valves is therefore
used as appropriate for the connection to the inexpensive water
supply which is based partly or fully on solar heating, and the
other valve is used for the connection to the customary cold water
connection line. Both valves can be used separately from each
other. The two valves are connected together via e.g. a T-shaped
connection piece which joins the lines together as an advantageous
connection device within the dishwasher, in particular the domestic
dishwasher. In the interior of the connection piece, a dual-action
non-return valve prevents in particular the flow of the liquid from
one side to the other, i.e. "crossover reverse flow". As a result
of the water pressure when one of the valves opens, for example,
this non-return valve seals the outflow to the other valve (and
vice versa). The water then has only a one-way option, flowing via
the output of the connection piece and only into the appliance. By
virtue of this solution, it is possible in particular additionally
to guarantee the accustomed water reliability of the waterstop
system. Advantageously, therefore, it is sufficient for the
waterstop or aquastop valves themselves only to be controllable to
the extent that, with their assistance, the water flow can be
controlled in the supply direction to the dishwasher, i.e. they
open and block the water flow in the inlet direction only. In this
case they need not always be sufficiently pressure-resistant in the
opposite direction, i.e. in the reverse direction. For with the aid
of the inventive connection device, provision is made for largely
preventing a water volume from uncontrollably entering the relevant
other water supply line, which is currently not carrying water, in
the reverse direction and reaching its aquastop valve on the
upstream side. The inventive connection device and its junction
part for its inputs, to which water inlet lines with upstream
terminal aquastop valves can be connected, can be provided in
particular in the interior of the relevant dishwasher or possibly
alternatively thereto as an external junction piece. Without the
selective backflow separation of the water supply lines in the
junction region of the connection device, however, a currently
running dishwashing program could be adversely affected by
unintended fillings. For example, an unintended filling of the warm
water supply line with backward-flowing cold water could result in,
instead of a requested warm water volume having a specific minimum
temperature, merely a different water volume mixture of cold water
and subsequent warm water arriving in the washing compartment of
the dishwasher, said mixture having a combined temperature that is
too low.
[0027] The above explanations relating to an available solar-heated
warm water supply system obviously apply analogously if another
external warm water connection is available in addition to the cold
water connection. For example, therefore, provision can be made for
a warm water connection of a warm water supply whose warm water is
provided by a conventional energy source such as e.g. gas condenser
heating and/or in particular by a regenerative energy source such
as e.g. a woodchip heating system, pellet furnace, geothermal pump
installation, local heating, etc. The delivery of warm water from
the warm water connection is then advantageously activated, in
particular by means of an operator pressing a special operating
button on the dishwasher or in particular by means of an automatic
selection by the control unit of the dishwasher, if a
dishwasher-internal heating device is less efficient than the
external warm water supply installation, i.e. would require higher
energy consumption than this to provide warm water.
[0028] Further embodiments and developments of the invention are
disclosed in the dependent claims. In this case the advantageous
embodiments and developments of the invention described above
and/or in the dependent claims can be applied to the inventive
dishwasher individually or in any desired combination.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The invention and its embodiments and developments and their
advantages are explained below with reference to drawings, in
which:
[0030] FIG. 1 schematically shows a domestic dishwasher which is
embodied according to an advantageous embodiment variant of the
invention,
[0031] FIG. 2 schematically shows an exemplary embodiment variant
of an inventive water supply system of the domestic dishwasher from
FIG. 1, and
[0032] FIG. 3 schematically shows an exemplary connection device of
the water supply system from FIG. 2.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE PRESENT
INVENTION
[0033] Elements having identical function and mode of operation are
denoted by the same reference signs in FIGS. 1 to 3.
[0034] FIG. 1 shows a domestic dishwasher 1 in cross-section as an
example of a water-carrying domestic appliance.
[0035] The domestic dishwasher 1 has a washing compartment 2 for
holding items to be washed which can be arranged e.g. in an upper
rack 3 and a lower rack 4. At least two spray devices for applying
a liquid to the dishes are arranged in the washing compartment 2,
said liquid normally being referred to as washing liquor. In the
case of the present exemplary embodiment, the spray devices are
embodied as upper and lower spray arms 5, 6. The liquid can be
conveyed by a circulating pump 7 via a first liquid feed line 8 to
the upper spray arm 5 and via a second liquid feed line 9 to the
lower spray arm 6. The circulating pump 7 is driven e.g. by means
of an electrical drive which is not shown in greater detail, and in
particular by means of the electric motor of said electrical
drive.
[0036] In the case of the present exemplary embodiment, the liquid
is heated in a subprogram step of a washing program of the domestic
dishwasher 1 by means of a flow-through water heater 10 which is
connected by means of an input nozzle 11 to the circulating pump 7
and by means of output nozzles 12, 13 to the liquid feed lines 8,
9. The number of output nozzles 12, 13 corresponds to the number of
spray arms 5, 6 or concurrently operated groups of spray arms 5, 6.
The liquid that is conveyed by the circulating pump 7 in the case
of the present exemplary embodiment is accordingly carried to the
input nozzle 11 of the flow-through heater 10 and from the output
nozzles 12, 13 thereof via the liquid feed lines 8, 9 to the spray
arms 5, 6.
[0037] The domestic dishwasher 1 additionally has a water switch 14
which is e.g. arranged in the flow-through water heater 10 or is
integrally molded on the latter. The water switch 14 can, however,
also be e.g. arranged independently in the domestic dishwasher 1 or
connected directly to the circulating pump 7.
[0038] By means of the water switch 14, the spray arms 5, 6 can be
in each case alternately and/or continuously supplied with the
liquid, this being achieved by means of opening one liquid outlet
and closing another liquid outlet of the water switch 14.
[0039] FIG. 2 shows a water supply system of the domestic
dishwasher 1 having a plurality of water connections.
[0040] In the case of the present exemplary embodiment, the
domestic dishwasher 1 has a plurality of water connections, in
particular in the form of a first inlet valve 15 and a second inlet
valve 16. The inlet valves 15, 16 are e.g. magnetic valves and are
attached to a control device of the domestic dishwasher 1 in a
manner which is not shown, said control device being configured
inter alia to control the operation of the domestic dishwasher 1
and to open and close the inlet valves 15, 16 selectively, i.e.
independently of each other. The two inlet valves 15, 16 are
provided for connection to a water line which is not illustrated in
greater detail or to a water supply network. One of the inlet
valves 15, 16 can be connected for example to a cold water
connection and the other to a warm water connection or a hot water
connection, in order to supply cold or preheated water to the
domestic dishwasher 1.
[0041] In the case of the present exemplary embodiment, the water
supply system of the domestic dishwasher 1 comprises a connection
device 17, as shown in FIG. 3, having a first input 18, a second
input 19 and an output 20. The first input 18 is attached to the
first inlet valve 15 via a water feed line, in particular via a
first water hose 21, and the second input 19 is attached to the
second inlet valve 16 via a further water feed line, in particular
via a second water hose 22. The output 20 of the connection device
17 is attached to an appliance inlet of the domestic dishwasher 1
e.g. via a further water hose. The water arriving from the water
connections enters the washing compartment 2 via the appliance
inlet in order to form the washing liquor when it is mixed with a
detergent.
[0042] In the case of the present exemplary embodiment, the
connection device 17 has a main body 23 which is implemented in
particular in a hollow cylindrical shape and is made e.g. of metal
or plastic. The main body 23 is implemented in particular in the
shape of a circular cylinder and has in particular the form of a
circular cylinder that is in particular straight. The two inputs
18, 19 connect to the two ends of the main body 23, i.e. to the
base surfaces of the circular cylinder.
[0043] In the case of the present exemplary embodiment, the output
20 of the connection device 17 connects to the lateral surface of
the circularly cylindrical main body 23, in particular midway
between the two inputs 18, 19.
[0044] In the case of the present exemplary embodiment, a movable
sealing means e.g. in the form of a piston 24 is displaceably
mounted within the main body 23, in particular along the
longitudinal axis L of the main body 23. The piston 24 is provided
so as to be moved in a translational manner between a first
position, in which it opens the first input 18 and seals the second
input 19, and a second position, in which it seals the first input
18 and opens the second input 19, i.e. linearly back and forth in
this case. The output 20 is always open in this case.
[0045] If the piston 24 is situated in its first position, a water
flow is allowed from the first inlet valve 15 via the first input
18 and the output 20 of the main body 23 of the connection device
17 into the appliance inlet of the domestic dishwasher 1, but any
backflow of water from the first inlet valve 15 into the second
water hose 22 is prevented.
[0046] If the piston 24 is situated in its second position, a water
flow is allowed from the second inlet valve 16 via the second input
19 and the output 20 of the main body 23 of the connection device
17 into the appliance inlet of the domestic dishwasher 1, but any
backflow of water from the second inlet valve 16 into the first
water hose 21 is prevented.
[0047] In the case of the present exemplary embodiment, the piston
24 is displaceably mounted along the longitudinal axis L of the
main body 23. Consequently it is possible, depending on which of
the two inlet valves 15, 16 opens, i.e. allows water to flow in via
the water hoses 21, 22 in the direction of the connection device
17, and solely as a result of the water pressure of the water
flowing through the relevant inlet valve 15, 16 and the subsequent
water hose 21, 22, for the piston 24 to be pressed against the
relevant input 18, 19 which is attached to the inlet valve 15, 16
that is currently blocked.
[0048] The water supply system can be implemented as a waterstop
system and accordingly include a safety mechanism in order to
prevent the supply of water if there is a fault in particular in
the water hoses 21, 22, e.g. by means of the control device
automatically blocking the inlet valves 15, 16. The two water hoses
21, 22 can be implemented as double hoses for this purpose.
[0049] In the case of the present exemplary embodiment, the
connection device 17 is arranged inside the domestic dishwasher 1,
and the water hoses 21, 22 are guided e.g. through a rear wall 25
of the domestic dishwasher 1.
[0050] In the connection device in which a plurality of water
hoses, i.e. generally expressed as a plurality of water inlet
lines, are merged into a common output or connected thereto,
provision is therefore made for a common backflow preventer which
closes or blocks the water inlet line that is not currently
supplying water in the inlet direction, against inflow of water in
a reverse direction from the other water inlet line which is
currently supplying water to the common outlet line. This backflow
preventer therefore functions as a type of water inlet branch which
only allows an outflow of incoming water to its output and no
backflow to its other input.
[0051] By this means a reverse flow of water from one feed line
into the other feed line is reliably prevented as a result of
providing a flow-based separation of the water inlets, in
particular their water inlet lines to the connection device. In
this way it is also possible to prevent water of the inlet line
that is currently carrying water from mixing with or contaminating
the inlet line that is not currently carrying water, i.e. is
blocking the water inlet, and possibly its upstream water supply
system. A clean and hygienically perfect separation of the two
water inlets is thus established. This is advantageous in
particular if there is a warm water supply installation within a
building, in particular a house, and an external cold water supply
system, in particular a water supply network, which is required to
provide water of drinking quality. Any backflow into said cold
water network is therefore prevented.
[0052] Furthermore, this backflow preventer ensures that the two
different water inlet flows, in particular hot and cold water,
cannot be mixed together in the water inlets upstream of said
backflow preventer in the feed lines, in particular as far as the
respective water connection, preferably a faucet. To put it another
way, a strict separation of the two water inlet flows from each
other is ensured at all times. As a result of this, if there is a
warm water inlet and a cold water inlet, a desired warm water
volume and a desired cold water volume can be supplied to the
output of the connection device selectively, i.e. separately at
different inlet times and in a precisely controllable manner, i.e.
metered. As a result of this, desired quantities of warm or cold
water can be fed in a specifically metered manner via the output of
the connection device into the liquid inlet system of the
dishwasher for the purpose of carrying out the various partial wash
cycles of a current wash cycle of a selected dishwashing program of
a domestic dishwasher. This allows specific proportioning of a
defined required warm water volume for at least one first partial
wash cycle, e.g. cleaning cycle or rinsing cycle, and a defined
required cold water volume for at least one second partial wash
cycle, e.g. prewash cycle, intermediate wash cycle and/or other
filling operation, e.g. filling a heat exchanger, in particular a
water pocket, in order to improve the condensation of water vapor
in the washing compartment as part of the drying operation, during
the execution of the dishwashing program selected in a given case.
Since warm water is only taken by the dishwasher when this is
required by said partial wash cycles and/or filling operations, and
cold water is used otherwise for the remaining partial wash cycles,
the dishwasher can be operated with greater energy efficiency
and/or greater drying efficiency.
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