WO 2006/123947 PCT/NZ2006/000114
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VENTING SYSTEM FOR DISHWASHER
BACKGROUND TO THE INVENTION
Field of the Invention
The present invention relates to a system for venting appliances which require
venting during their operation, such as dishwashers and in particular to appliances which are
designed for installation in surrounding furniture or joinery structures.
Background to the Invention
Automatic dishwashers typically operate a washing cycle which include a number of
discrete operating stages, just as washing, rinsing and drying. During the drying stage, moist
air within the wash chamber, remaining after the washing and rinsing stages, must be replaced
with dry air. In order to replace the moist air with dry air, the moist air must have a means of
escape from the wash chamber. This is achieved through a venting system, connecting the
wash chamber with the exterior of the appliance.
Venting systems typically comprise a venting conduit extending between the wash
chamber and the outer wrapper of the dishwasher. The venting conduit often includes at least
one valve which can be actively or passively operated to control venting.
Increasingly, there is demand for appliances such as dishwashers to match
surrounding kitchen furniture. These dishwashers must fit within a tight cavity formed by
kitchen joinery and have a front face panel attached which matches the surrounding kitchen
furniture. So called "integrated" dishwashers presents particular problems for venting during
the drying stage. The dishwasher is surrounded in all sides by kitchen joinery preventing easy
escape of moist air and intake of dry air. Furthermore, the desired clearance between the
joinery and the dishwasher is decreasing, making efficient venting even more difficult. In the
US door fronts often overlap leaving no space for venting, and some models of dishwasher
prevent access to the kickstrap. To compound this problem, venting moist air into the space
between the dishwasher and the joinery can cause condensation on the joinery which can
damage the joinery.
US2004/0163684 discloses a dishwasher with an automatically openable door. The
door may be moved into an open position during a venting stage of the wash cycle. However,
simply opening the door to provide venting removes control over the venting process. It is

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desirable to have full control over the rate, volume and mixing ratio of the exhausting air
during venting.
It would be desirable to provide a means for venting integrated automatic
dishwashers that is efficient, controlled and does not damage surrounding joinery.
Accordingly, it is an object of the present invention to provide a venting system
which will go at least someway towards meeting the above desideratum or which will at least
provide the public with a useful choice.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, an appliance comprises:
a sealable chamber;
a door for the sealable chamber, wherein in an opened position the door allows
access to the chamber; and
a venting system for allowing air to escape from the sealable chamber when the door
is in a closed position,
wherein the venting system includes a vent flap, the vent flap moveable from a
closed position sealing the vent system to an open position allowing air to escape.
Preferably, the vent flap forms at least part of the exterior surface of the appliance.
Preferably, the vent flap forms part of the door. Preferably, in an open position the vent flap
extends exteriorly of the door.
Preferably, the appliance is adapted for placement in joinery structure or kitchen
furniture.
Preferably, the vent flap is tiltable between an open position and a closed position.
Alternatively, the vent flap could undergo translational motion between an open position and
a closed position.
Preferably, the appliance further includes an actuator for moving the vent flap
between the closed position and the open position. The appliance may also include a biasing
element connected to the vent flap, for biasing the vent flap into the closed position.
Preferably, the appliance includes a controller for controlling the operation of the
appliance.
Preferably, the controller is connected to the actuator, in use the controller
controlling the actuator in accordance with an operating cycle of the appliance.
Preferably, the venting system includes a mixing chamber for mixing air from the
chamber with external air, in order to control the moisture content of the air exiting the

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venting system. Preferably, the venting system includes a variable speed fan. The variable
speed fan may be connected to the controller.
Preferably, the door is slideable between open position and a closed position and the
sealable chamber is coupled to the door and is slideable with the door.
Preferably, the appliance is a dishwasher.
Preferably, the vent flap is actuated in accordance with the washing cycle of the
dishwasher.
Preferably, the door is adapted to receive an exterior face panel coupled to the vent
flap wherein the vent flap moves the exterior face panel.
According to a second aspect of the invention, a dishwasher comprises:
a sealable chamber;
a door for the sealable chamber, wherein in an opened position the door allows
access to the chamber; and
a venting system for allowing air to escape from the sealable chamber when the door
is in a closed position,
wherein the venting system includes a vent flap, the vent flap moveable from a
closed position sealing the vent system to an open position allowing air to escape.
Preferably, the dishwasher is a drawer type dishwasher.
According to a third aspect of the invention, there is provided a venting system for an
appliance having a sealable chamber, wherein the venting system allows air to escape from
the sealable chamber when the appliance is in a closed configuration, and
wherein the venting system includes a vent flap on an exterior surface of a door of
the appliance, the vent flap moveable from a closed position sealing the vent system to an
open position allowing the air to escape.
According to a fourth aspect of the invention, a method for venting an appliance
comprises the step of moving a vent flap from a closed position to an open position, wherein
the vent flap forms part of the exterior surface of the door of the appliance and wherein the
door remains in a closed position.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention are now described, by way of example only, with
reference to the drawings in which:
Figure 1 is a schematic illustration of a dishwasher in accordance with the present
invention.

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Figure 2a shows the dishwasher of Figure 1 with the vent flap in an open position.
Figure 2b shows an alternative embodiment of a dishwasher with the vent flap in an
open position.
Figure 3 shows a hinge for the vent flap in accordance with a first example of the
present invention.
Figure 4 shows a linkage arrangement for the vent flap in accordance with a second
example of the present invention.
Figure 5 shows a cam arrangement for the vent flap in accordance with a third
example of the present invention.
Figure 6 shows detail of an actuator mechanism that for the vent flap in accordance
with an example of the present invention.
Figure 7 is a flow chart illustrating the control of a venting system in accordance
with the present invention.
Figure 8 shows an integrated drawer type dishwasher in various configurations in
accordance with the present invention.
Figure 9 shows an integrated oven in accordance with the present invention.
DETAILED DESCRIPTION
The present invention provides a vent system for an appliance, such as an automatic
domestic dishwasher. Figure 1 is a schematic cross section of a dishwasher. The dishwasher
of Figure 1 is of the slideable drawer type disclosed in WO93/12706, the contents of which
are incorporated herein by reference. The dishwasher may be of the "cabinetless" type,
suitable for integrated installation, as described in WO01/26532, the contents of which are
also incorporated herein by reference. Whilst the following description refers to a drawer
type dishwasher, the present invention is applicable to conventional hinged door dishwashers
and to other types of appliance, such as ovens, clothes driers and refrigerators.
The dishwasher comprises a wash chamber 10 and a door assembly 12. The door
assembly may include electronics and a user interface to allow a user to programme the
dishwasher but for clarity these are not shown. In a drawer type dishwasher as illustrated in
Figure 1, the door assembly is fixed to the wash chamber and is slideable with the wash
chamber to an open position in which the wash chamber can be accessed from above. The
door includes a vent flap 11 which is moveable to an open position to provide for venting of
the wash chamber, while the dishwasher remains in a closed position, so that the wash
chamber remains substantially sealed.

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Figure 2a shows the dishwasher of Figure 1 with the vent flap in an open position
and the door assembly is in a closed position. The vent flap is connected to a front face panel
14 and preferably covers the entire door. This allows the dishwasher door to be simply
covered with a unitary cabinet door to match surrounding kitchen furniture, while allowing
the vent flap 11 to operate. However, it should be recognised that a front face panel is not
necessary and the vent flap 11 can be made aesthetically pleasing itself.
Both Figure 1 and Figure 2a illustrate the basic features of a vent system in
accordance with one example of the present invention. The dishwasher includes an exit
conduit 16 for air in the wash chamber 10. The wash chamber consists of a tub 15 and a lid
17. Air in the wash chamber 10 is sucked out through the exit conduit 16 when fan 18 is
operated. The fan 18 is located in a mixing chamber 20. Moist air from the wash chamber is
mixed with dry air in the mixing chamber. The dry air enters the mixing chamber via chassis
air inlet 22. Chassis air is ambient air that is present in the space surrounding the wash
chamber. Air can enter the chassis space through various openings in the chassis of the
dishwasher but principally will enter the chassis space when the vent flap 11 is in the open
position. The mixture of moist wash chamber air and dry chassis air is driven through exhaust
duct 24 by the fan 18 and out into the external space adjacent the dishwasher door. The exit
conduit or exhaust duct may include one or more valves to prevent ingress or egress of air
from and to the wash chamber during the wash cycle.
The air sucked out of the wash chamber 10 by fan 18 is replaced by dry chassis air.
The dry chassis air enters the wash chamber through air inlet 26. The air inlet 24 may include
a valve which can be actively or passively controlled or the air inlet may be of a labyrinthine
configuration to prevent egress of air from the wash chamber via the inlet 26.
The exhaust duct 24 is shown in Figures 1 and 2a as moving with the vent flap, the
end of the exhaust duct being obstructed by the door structure in a closed position.
Alternatively, as shown in Figure 2b, the exhaust duct 28 may be stationary within the door
structure, the end of the exhaust duct 28 being obstructed by the vent flap 11 when the vent
flap is in a closed position and unobstructed when the vent flap is in an open position.
There are many possible mechanisms that can be used to attach the vent flap to the
appliance. Figure 3 illustrates a simple hinge connecting the vent flap 11 to the body of the
door assembly 12. Figure 3a shows the flap in a closed position and Figure 3b shows the flap
in an open position. A pair of hinges 30 could be placed on opposite sides of the flap 11. The
hinges could be placed on any edge of the vent flap to allow the vent flap to tilt between a
closed position and an open position.

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Figure 4 illustrates a link mechanism connecting the vent flap 11 to the rest of the
door assembly 12 as an alternative. The link mechanism comprises a pair of link members 40
of unequal length. Figure 4a shows the vent flap in a closed position and Figure 4b shows the
flap in an open position. Pushing the vent flap outwardly causes the vent flap to pivot out and
down and pulling the vent flap inwardly causes the flap to pivot up and in.
Figure 5 illustrates a further alternative, a camming arrangement, for opening the
vent flap.
Figure 5a shows the flap in a closed position and Figure 5b shows the flap in an open
position. Two channels 50 are provided in each side of the body of the door assembly 12.
Corresponding cams 51 attached to the vent flap 11 are located in the channels 50. A pair of
hinges 52 is provided at the top of the vent flap 11. Pushing the vent flap 11 outward or
pulling it inward causes the cams 51 to slide in the channels 50. The channels can be shaped
to provide for a desired motion of the vent flap.
An alternative connection for the vent flap 11 is to mount it on a pair of sliders. The
vent flap is translatable on sliders from a closed position to an open position and back to a
closed position.
Figure 6 shows detail of an actuator mechanism that is used to operate the opening
and closing of the vent flap. Figure 6a shows the vent flap 14 in an open position. An
actuator mechanism 60, 62 is mounted centrally at the base of the door assembly 12. The
actuator mechanism comprises a DC motor 60 and an actuator rod 62. A DC motor is used in
this example, but it will be appreciated that there are a number of alternatives, such as an AC
motor, a solenoid and a wax actuator. It is also possible to use more than one actuating means,
for example two symmetrically mounted DC motors.
The DC motor is used to drive the actuator rod using a rack and pinion type coupling.
The actuator rod 62 contacts the vent flap 14 and when driven towards the exterior of the
appliance causes the vent flap to move to an open position. The vent flap is connected to the
appliance door by a simple hinge 30 in this example. Figure 6b shows the vent flap in a
closed position. The actuator rod is withdrawn into the body of the appliance, underneath the
wash chamber 10. Figure 6c shows biasing means 64, 66 for biasing the vent flap in a closed
position. Figure 6c shows the rear side of the door 12. The DC motor is mounted centrally at
the base of the door. The vent flap is attached to a pair of tension springs 66 via wires 64
passing through the door. When the vent flap is moved to an open position via the action of
the actuator rod 62, the springs are extended and under tension. As the actuator rod 62 is
withdrawn the action of the springs 66 forces the vent flap 12 to remain in contact with the

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actuator rod 62 until the closed position is reached as shown in Figure 6b. The DC motor is
connected to and controlled by a controller or microprocessor 68 which controls the operation
of the dishwasher
The rate of venting of the wash chamber can be controlled by altering the speed of
the fan 18. The inlets 16, 22 to the mixing chamber 20 may be provided with movable parts,
such as controllable valves, in order to control the moisture content of the air exiting the
venting system via exhaust duct 24.
Venting is carried out during a drying stage of the dishwasher cycle. The dishwasher
door remains in a closed position during the venting stage and the wash chamber remains
substantially sealed. The venting flap is in a closed position when the dishwasher is not
operating and during various stages of the dishwasher cycle. The vent flap is automatically
opened at the appropriate stage in the wash cycle. The dishwasher cycle is electronically
controlled by a programmed microcomputer. The microcomputer is connected to the vent
flap opening mechanism and controls the opening and closing of the vent flap.
Figure 7 is a flow diagram showing the operation of the venting system during the
operation cycle of a drawer type dishwasher. The operation cycle starts at step 700. After the
wash cycle stages of pre-wash, wash and rinse, a drain step 705 takes place. After the wash
chamber has been drained, the vent flap is pushed out by the actuator at step 710. The drying
cycle then starts with the fan turned on to suck air out of the wash chamber at step 715.
It may be possible to stop or pause the operation of the dishwasher during the drying
cycle. This can be achieved by pressing a stop/power button or pause button respectively.
The option for pressing the stop button is shown in box 720 and the option for the pause
button in box 725. If neither the stop/power button nor the pause button is pressed, then the
drying cycle completes after a predetermined time and the fan is switched off, indicated by
step 730. After the drying cycle is completed, the actuator is pulled in and the vent flap
returns to the closed position at step 735. Following retraction of the vent flap at step 740 the
lid of the wash chamber is raised to allow the chamber to be withdrawn from the surrounding
cabinetry. The operation cycle is then at an end, at indicated at step 745.
If the stop/power button is pressed during the drying cycle the fan is switched off, as
indicated at step 750. The vent flap is then returned to the closed position at step 755, the lid
of the wash chamber raised at step 760 and the wash cycle is then at an end at step 765. As
soon as the lid is raised the wash chamber can be withdrawn to provide access to its contents.
If the pause button is pressed during the drying cycle then the fan is stopped, as
indicated in step 770. The vent flap is then moved to the closed position at step 775, the wash

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chamber lid is raised at step 780 and the wash chamber can be withdrawn. Until the drying
cycle is restarted by depression of the pause button nothing further happens, as indicated at
step 790. If the drying cycle is restarted at step 785 then, if the wash chamber is folly
retracted, the lid is closed to seal the wash chamber at step 795. The vent flap is pushed out at
step 800 and the drying cycle is then resumed, with the fan switched in, at step 805. The time
remaining for the drying cycle is calculated using a timer in the controller.
Figure 8 shows an integrated dishwasher of the type described with reference to
Figures 1 and 2. Figure 8a shows a set of kitchen cabinets. The dishwasher is placed in the
centre of the top row. In a closed position, with the vent flap 14 closed, as shown in Figure
8a, the front face panel of the dishwasher matches and is flush with the surrounding cabinetry
80. In a drying stage of the cycle of operation the vent flap 14 is tilted out to an open position,
as shown in Figure 8b. In order to load and unload the dishwasher the door is pulled out with
the wash chamber to provide access to the wash chamber from above, as shown in Figure 8c.
Figure 9 shows an integrated oven in accordance with the present invention. Two
types of oven are illustrated, a conventional hinged door oven and a drawer type oven. Figure
9a shows the oven door and vent flap in a closed position. The front face panel of the oven 93
matches the surrounding cabinetry. Figure 9b shows the vent flap in an open position. The
vent flap is connected to the front face panel and is provided with an exhaust outlet 94
analogous to the exhaust duct of the dishwasher previously described. Figure 9c shows a
conventional type oven with the door 91 in an open position. The vent flap 92 and the door 91
move together to allow for access to the oven chamber. Figure 9d shows a drawer type oven
in a open position. Again the vent flap 92 and the door 91 move in unison to allow for access
to the oven chamber. The same type of actuation can be used for the vent flap for the oven as
for a dishwasher.
The venting system of the present invention allows for controlled venting during the
operation of an integrated appliance, such as a dishwasher, oven, refrigerator or clothes drier,
without relying on there being sufficient space between the appliance and the surrounding
furniture. The invention therefore allows appliances to fit tightly into cavities in furniture
without compromising performance and without damaging the furniture during operation. It
is particularly suited to drawer type dishwashers in which venting cannot be performed via a
kickstrap near to the floor. Furthermore, the venting system of the present invention allows
the front of the appliance to match surrounding furniture and in operation is elegant and
unobtrusive.

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AMENDED CLAIMS
received by the International Bureau on 22 September 2006 (22.09.06)
1. An appliance comprising:
a sealable chamber;
a door for the sealable chamber, wherein in an opened position the door allows
access to the chamber; and,
a venting system for allowing air to escape from the sealable chamber when the door
is in a closed position,
wherein the venting system includes a vent flap, the vent flap moveable from a
closed position sealing the vent system to an open position allowing air to escape wherein the
vent flap forms part of the door and wherein in an open position the vent flap extends
exteriorly of the door..
2. An appliance according to claim 1, wherein the vent flap forms at least part of the
exterior surface of the appliance.
3. An appliance according to any one of the preceding claims, wherein the appliance is
adapted for placement in a joinery structure or kitchen furniture.
4. An appliance according to any one of the preceding claims, wherein the vent flap is
tiltable between an open position and a closed position.
5. An appliance according to any one of the preceding claims, further comprising an
actuator for moving the vent flap between the closed position and the open position.
6. An appliance according to any one of the preceding claims, further including a
biasing element connected to the vent flap, for biasing the vent flap into the closed position.
7. An appliance according to any one of the preceding claims, further comprising a
controller for controlling the operation of the appliance.
8. An appliance according to claim 7, wherein the controller is connected to the
actuator, in use the controller controlling the actuator in accordance with an operating cycle of
the appliance.
AMENDED SHEET (ARTICLE 19)

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9. An appliance according to any one of the preceding claims, wherein the venting
system includes a mixing chamber for mixing air from the chamber with external air, in order
to control the moisture content of the air exiting the venting system.
10. An appliance according to any one of the preceding claims wherein the venting
system includes a variable speed fan.
11. An appliance according to claim 10, wherein the variable speed fan is connected to
the controller.
12. An appliance according to any one of the preceding claims, wherein the door is
slideable between open position and a closed position and the sealable chamber is coupled to
the door and is slideable with the door.
13. An appliance according to any one of the preceding claims, wherein the appliance is
a dishwasher.
14. An appliance according to claim 13, wherein the vent flap is actuated in accordance
with the washing cycle of the dishwasher.
15. An appliance according to any one of the preceding claims, wherein the door is
adapted to receive an exterior face panel coupled to the vent flap wherein the vent flap moves
the exterior face panel.
16. A dishwasher comprising:
a sealable chamber;
a door for the sealable chamber, wherein in an opened position the door allows
access to the chamber; and
a venting system for allowing air to escape from the sealable chamber when the door
is in a closed position,
wherein the venting system includes a vent flap, the vent flap moveable from a
closed position sealing the vent system to an open position allowing air to escape, wherein the
AMENDED SHEET (ARTICLE 19)

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vent flap forms part of the door and wherein in an open position the vent flap extends
exteriorly of the door.
17. A dishwasher according to claim 16, wherein the dishwasher is a drawer type
dishwasher.
18. A venting system for an appliance having a sealable chamber, wherein the venting
system allows air to escape from a sealable chamber when the appliance is in a closed
configuration, and
wherein the venting system includes a vent flap on an exterior surface of a door of
the appliance, the vent flap moveable from a closed position sealing the vent system to an
open position allowing air to escape, wherein in an open position the vent flap extends
exteriorly of the door.
19. An appliance comprising:
a sealable chamber;
a door for the sealable chamber, wherein in an opened position the door allows
access to the chamber, and
a venting system for allowing air to escape from the sealable chamber when the door
is in a closed position;
wherein the venting system includes an exhaust duct and a vent flap, the vent flap
moveable from a closed position in which the exhaust duct is obstructed to an open position in
which the exhaust duct is unobstructed, and wherein the vent flap forms part of the door and
extends exteriorly of the door when in an open position.
20. A method for venting an appliance, comprising the step of moving a vent flap from a
closed position to an open position, wherein the vent flap extends exteriorly of the door of the
appliance where in an open position, wherein the vent flap forms part of the exterior surface
of a door of the appliance, wherein the vent flap extends exteriorly of the door of the
appliance wherein in an open position, and wherein the door remains in a closed position.
AMENDED SHEET (ARTICLE 19)

An appliance comprising a sealable chamber (10) and a door (12) for the sealable chamber (10), wherein in an opened
position the door (12) allows access to the chamber (10); and a venting system for allowing air to escape from the sealable chamber
(10) when the door (12) is in closed position, wherein the venting system includes a vent flap (11), the vent flap (11) moveable from
a closed position sealing the vent system to an open position allowing air to escape. The venting system allows an appliance, such
as dishwasher, to expel unwanted air or vapour in a controlled manner whilst the appliance remains closed.