[0001] The present invention generally relates to the field of household appliances. More
specifically, the present invention relates to laundry washing machines and laundry
washing/drying machines, both for domestic and professional use.
[0002] Laundry washing and washing/drying machines (hereinafter simply referred to as "washing
machines") are household appliances designed to wash laundry and typically comprise
a washing tub housing a rotatable perforated drum in which the laundry to be washed
can be loaded/unloaded.
[0003] In order to carry out washing operations on laundry loaded into the drum, washing
liquid (
e.g., water, water mixed with washing products and/or water mixed with rinsing products)
is introduced - through an inlet line - in the washing tub of the washing machine
during a washing liquid loading phase. Being the drum perforated, the washing liquid
penetrates thereinto, soaking the laundry.
[0004] Then, a washing phase is started in which the drum is rotated, so that the laundry
loaded into the drum is washed thanks to the chemical reactions exerted by the washing
liquid, supported by the tumbling action caused by the rotation of the drum.
[0005] At the end of the washing phase, the washing liquid (which is at this point mixed
with dirt particles coming from the laundry) is removed from the washing tub for allowing
the carrying out of rinsing and/or spin-drying operations on the laundry.
[0006] For this purpose, the washing machine is provided with a discharge system adapted
to selectively drain the washing liquid from the washing tub. The discharge system
comprises a discharge duct for receiving the washing liquid to be discharged. The
discharge duct is fluidly coupled with the washing tub through a discharge hole provided
at the bottom of the washing tub. A drain pump, usually positioned downstream the
discharge duct, is operable to cause the washing liquid located into the discharge
duct to be discharged through a drain hose adapted to be connected to the water drain
network system. In some types of know washing machines, a valve is provided for selectively
opening/closing the discharge hole in order to selectively allow/block washing liquid
to flow between the washing tub and the discharge duct.
[0007] On this regard, valves of the floating type - hereinafter, "floating valves" - are
known, comprising a floating closure member arranged in the discharge duct and adapted
to open/close the discharge hole based on the amount of liquid located in the discharge
duct. The floating closure member is buoyant in the washing liquid. As the level of
liquid in the discharge duct increases, the floating closure member is pushed toward
the washing tub. The floating valve further comprises a valve seat, for example a
gasket member, provided with an opening for allowing liquid to pass from the washing
tub to the discharge duct when the floating closure member is spaced apart from the
valve seat. When the floating closure member abuts against the valve seat because
of the pressure exerted by the liquid located in the discharge duct, the opening of
the valve seat is closed by the floating closure member, preventing further exchanges
of fluids between the washing tub and the discharge duct.
[0008] Before performing the washing liquid loading phase, the floating valve should be
closed, in such a way to avoid that the clean washing liquid that is supplied in the
subsequent phase is wasted in the discharge duct without being participated in the
washing process, to avoid that dirt residual accumulated in the discharge duct mixes
with the supplied washing liquid, as well as to thermally insulate the washing tub
from the discharge duct.
[0009] For this purpose, a valve closing phase may be carried out before starting the actual
washing liquid loading phase. During this valve closing phase, firstly, a prefixed
amount of water is introduced in the washing tub through the inlet line; since when
the discharge duct is empty the floating valve is still open, this prefixed amount
of water flows through the valve into the discharge duct, forming a corresponding
water column in the drain hose. The drain pump is then turned on impulsively (for
example, it is activated for one second) for decreasing the level of water in the
discharge duct and correspondingly increasing the level of the water column contained
in the drain hose. Once the drain pump is turned off, water flows back from the drain
hose to the discharge duct under the action of the gravity force in order to try to
re-establish the condition reached prior to the activation of the drain pump, exerting
a pressure which causes the floating closure member to abut against the valve seat
and close its opening.
[0010] However, during the flow back of the water, air sucked by the drain pump from the
washing tub during the impulsive activation of the pump concentrates in the portion
of the discharge duct located between the lower side of the valve seat and the floating
closure member. Such amount of air elastically opposes to the floating valve closure,
disadvantageously reducing the leak-proofing thereof.
[0011] International patent application No.
WO2009/083365 discloses a washing machine in which the valve or the hose have at least some portions
thereof surrounding the volume wherein air is concentrated that is produced of a gas
permeable water impermeable material, allowing the air to be discharged during the
valve closure.
[0012] The Applicant has found that a solution of this type it is not efficient in terms
of production costs, since some of the components of the washing machine should be
implemented with specific gas permeable water impermeable materials, which are very
costly. Moreover, such materials are particularly prone to wear, and require an improved
maintenance.
[0013] In a further known solution, an air passage,
e.g., a hole, is provided, which connects the discharge duct with the washing tub for
allowing air trapped in the discharge duct to be discharged in the washing tub during
the valve closure, increasing the leak-proofing of the floating valve, without having
to employ materials specifically designed to be gas permeable and water impermeable.
In order to minimize the amount of washing liquid that might pass into the discharge
duct during the washing operations through such an air passage, the latter is advantageously
designed to have a small cross section.
[0014] However, when such an air passage is present, a certain amount, even if small, of
the washing liquid present in the discharge duct may flow through the air passage,
reaching the washing tub. For example, during the above described valve closing phase,
after the drain pump is turned off, a certain amount of the water, pushed by the gravity
force from the drain hose towards the valve seat may enter the air passage and gush
into the water tub, possibly reaching the lateral wall of the drum and, via the holes
provided in the latter, the laundry contained therein. This may disadvantageously
soil the laundry, since liquid coming from the discharge duct may be dirty, because
of dirt accumulated in the discharge duct after washings and/or because of the presence
of foreign bodies settled in the discharge duct, such as coins, which may release
rust particles in the water.
[0015] Applicant has handled the problem of devising a not-expensive solution which allows
reducing the drawbacks caused by the abovementioned concentration of air in the discharge
duct, avoiding at the same time that the laundry contained in the drum is soiled.
[0016] In very general terms, the solution according to one or more embodiments of the invention
is based on the idea of providing an intercepting member arranged to prevent a liquid
flow exiting the air passage connecting the discharge duct with the washing tub from
hitting the washing drum of a washing machine.
[0017] In this way, it is possible preventing that possible dirty liquid contacts the drum
(reducing therefore the risk that this liquid soils the laundry contained therein),
allowing at the same time the air trapped in the discharge duct to be discharged in
the washing tub during the closure of the valve which selectively allows/blocks the
washing liquid to flow between the washing tub and the discharge duct.
[0018] In particular, one aspect of the present invention proposes a washing machine. The
washing machine comprises a washing tub in which washing liquid may be loaded, a perforated
drum rotatably accommodated in the washing tub for containing laundry to be washed,
and a discharge system fluidly connected to the washing tub and adapted to selectively
discharge washing liquid from the washing tub. The washing machine further comprises
a valve, placed between the washing tub and the discharge system. The valve comprises
a valve seat through which liquid can pass from the washing tub to the discharge system.
The valve further comprises a closure member movable with respect to the valve seat
from a closing position, in which said closure member abuts against the valve seat,
impeding the flow of washing liquid from the washing tub to the discharge system,
to an open position in which said closure member is at least partially spaced apart
from the valve seat, allowing the flow of washing liquid from the washing tub to the
discharge system. The washing machine further comprises an air passage fluidly connecting
said discharge system and said washing tub for allowing the passage of at least air
from the discharge system to the washing tub. The washing machine further comprises
an intercepting member arranged to prevent a liquid flow exiting said air passage
from hitting said drum.
[0019] Preferred features of the present invention are set in the dependent claims.
[0020] According to an embodiment of the present invention, said intercepting member is
arranged in such a way to intercept a liquid flow exiting said air passage and directed
toward the drum.
[0021] According to an embodiment of the present invention, the intercepting member is arranged
to deflect away from the drum a liquid flow exiting said air passage.
[0022] According to an embodiment of the present invention, the intercepting member comprises
a deflecting surface displaced transversally, preferably perpendicularly, to the longitudinal
axis of said air passage.
[0023] According to an embodiment of the present invention, said air passage comprises an
air pipe extending substantially parallel to the longitudinal axis of the discharge
hole.
[0024] According to an embodiment of the present invention, said air pipe comprises a first
air pipe having a top end with a first opening located in the washing tub interior
and having a bottom end with a second opening facing the discharge system.
[0025] According to an embodiment of the present invention, the intercepting member is placed
in proximity of the top end of the first air pipe.
[0026] According to an embodiment of the present invention, said first air pipe is integral
with the washing tube.
[0027] According to an embodiment of the present invention, the valve seat includes a hole
facing said second opening.
[0028] According to an embodiment of the present invention, said air passage comprises a
second air pipe integral with the valve seat and coaxially fitted inside the first
air pipe.
[0029] According to an embodiment of the present invention, said first air pipe is integral
with the valve seat.
[0030] According to an embodiment of the present invention, said air passage comprises a
hole located on said valve seat.
[0031] According to an embodiment of the present invention, the intercepting member is integral
with the washing tub.
[0032] These, and others, features and advantages of the solution according to the present
invention will be better understood by reading the following detailed description
of some embodiments thereof, provided merely by way of exemplary and non-limitative
examples, to be read in conjunction with the attached drawings, wherein:
Figure 1 is a schematic front view of a washing machine in which embodiments of the
present invention may be implemented;
Figure 2 is a partially exploded view of a washing tub of the washing machine of Figure
1;
Figure 3 is a partially exploded view of a portion of a discharge system of the washing
machine of Figure 1;
Figure 4 is a simplified cross-sectional view of a drum-washing tub-discharge system
assembly according to an embodiment of the present invention, and
Figure 5 is a simplified cross-sectional view of a drum-washing tub-discharge system
assembly according to another embodiment of the present invention.
[0033] With reference to the drawings, Figure 1 is a front view of a washing machine 100
in which embodiments of the present invention may be implemented.
[0034] The washing machine 100 is a machine for treating (washing, or washing/drying) laundry
of the front-loading type. Anyway, it should be apparent from the following description
that the inventions can be applied, without any substantial modification, to a washing
machine of the top-loading type.
[0035] In the example at issue, the washing machine 100 advantageously comprises a preferably
substantially parallelepiped-shaped casing 105 that encloses a washing tub 107 wherein
laundry is treated, along with any other components of the washing machine 100 necessary
for the operation (
e.g., hydraulic, electronic and electromechanical apparatuses known in the art and, therefore,
not herein described for sake of conciseness).
[0036] The washing tub 107 houses a rotatable perforated drum 110, preferably substantially
cylindrical-shaped, in which laundry 112 to be washed can be loaded.
[0037] In order to allow a user to access the washing tub and the inside of the drum 110
(for loading/unloading the laundry), a loading/unloading opening closable by a door,
not illustrated, is advantageously provided, preferably on a front side of the washing
machine 100.
[0038] A water supply system 120 and a detergent supply system 122 are arranged preferably
in the upper part of the washing machine 100 for supplying washing liquid into the
washing tub 107. The detergent supply system 122 advantageously comprises a removable
drawer 123 provided with compartments suited to be filled with washing and/or rinsing
products.
[0039] Water flowing through the water supply system 120 is advantageously supplied into
the washing tub 107 by making it flow through the drawer 123 and through an inlet
line 125 in fluidly communication with the washing tub 107. The water supply system
120 further comprises a main pipe 130 fluidly connecting the drawer 123 to an external
water supply line 135, preferably by means of a controlled input supply valve 140.
[0040] Washing liquid which reaches the washing tub 107 may selectively contain one of the
products contained in the compartments of the drawer 123, or may be clean water (
i.e., which does not contain any product), depending on the washing program which is actually
performed. For example, during a washing phase, the washing liquid conveyed into the
washing tub 107 is made to contain one of the products contained in the compartments
of the drawer 123, while in other phases, for example during the rinsing phase, the
washing liquid is only water. Alternative arrangements may be provided, for example
with a separate water inlet line adapted to supply exclusively clean water into the
washing tub 107.
[0041] Figure 2 is a partially exploded view of an exemplary washing tub 107. The washing
tub 107 has preferably a substantially cylindrical shape and is made of waterproof
material which is also able to withstand operating temperatures and chemicals reactions
promoted by washing liquids during the washing machine operation, such as a plastic
polymer. The washing tub 107 comprises a front semi-shell section 205a and a rear
semi-shell section 205b, each having preferably substantially the shape of a hollow
half-cylinder. The front semi-shell section 205a and the rear semi-shell section 205b
are coupled to each other (
e.g., by means of pins or bolts, or welding) to enclose therebetween the drum 110.
[0042] The washing machine 100 is provided with a discharge system 300 adapted to selectively
dispose washing liquid from the washing tub 107,
e.g., after a washing phase is finished.
[0043] Figure 3 is a partially exploded view of a portion of an exemplary discharge system
300.
[0044] Making reference to Figures 1-3, the discharge system 300 comprises a discharge duct
310 arranged to be coupled with the washing tub 107 for receiving the washing liquid
to be discharged. In the example illustrated in Figure 3, the discharge duct 310 is
a manifold made of a rigid material, such as plastic. Anyway, in a further advantageous
embodiment, the discharge duct 310 may be a flexible hose, for example made in a flexible
material, such as rubber. The discharge duct 310 is arranged to be selectively in
fluid communication with the washing tub 107, preferably through a discharge hole
210 provided at the bottom of the washing tub 107. In the example illustrated in Figure
2, the discharge hole 210 is provided at a bottom portion of the front semi-shell
section 205a. Naturally, similar considerations apply with different configurations,
such as for example if the discharge hole 210 is located at the rear semi-shell section
205b, or if the discharge hole 210 is located partially at the at the front semi-shell
section 205a and partially at the rear semi-shell section 205b.
[0045] The way the discharge duct 310 and the washing tub 107 are coupled one to another
may depend on various factors, such as the materials and the shapes thereof. In the
example at issue, the washing tub 107 advantageously includes a drain collar - identified
in Figure 2 with the reference 215 - surrounding the discharge hole 210 and protruding
downward from the front semi-shell section 205a, and the discharge duct 310 comprises
a discharge duct input opening 315 surrounded by a sleeve 317 adapted to be fitted
around the drain collar 215.
[0046] The discharge system 300 advantageously further comprises a drain pump 320,
e.g., positioned downstream the discharge duct 310, which is operable to cause liquid
located into the discharge duct 310 to be discharged through a drain hose 322 (see
Figure 1) adapted to be connected to a water drain network system (not illustrated).
[0047] The discharge system 300 further comprises a valve 330 advantageously located at
the discharge duct input opening 315 for selectively opening/closing the discharge
duct input opening 315, and thus the discharge hole 210 as well, in order to selectively
allow/block liquid to flow between the washing tub and 107 the discharge duct 310.
[0048] The valve 330 is preferably a floating-type valve, comprising a floating closure
member 340 arranged in the discharge duct 310 in such a way to allow/prevent the passage
of liquid from the tub 107 to the discharge duct 310, preferably based on the amount
of liquid located in the discharge duct 310. The floating closure member 340 is advantageously
made of a material and/or has a shape (for example including hollow cavities) that
makes the floating closure member 340 to float in the washing liquid. As the level
of liquid in the discharge duct 310 increases, the floating closure member 340 goes
up the discharge duct 310, being pushed toward the washing tub 107 interior by the
pressure exerted by the column of liquid located in the drain hose 322. The valve
330 further comprises a valve seat 350 adapted to be arranged at the discharge hole
210 of the washing tub 107. The valve seat 350 is preferably in the form of a,
e.g., flexible, gasket, for example fitted on the sleeve 317 wherein the discharge duct
input opening 315 of the discharge duct 310 is located. Similar considerations apply
if the valve seat 350 is fitted on the drain collar 215 surrounding the discharge
hole 210. The valve seat 350 is advantageously provided with a seat opening 360 -
which opportunely faces the discharge hole 210 and the discharge duct input opening
315 - for allowing liquid to pass from the washing tub 107 to the discharge duct 310
when the floating closure member 340 is spaced apart from the valve seat 350. When
the floating closure member 340 abuts the valve seat 350 because of the pressure exerted
by the column of water located in the drain hose 322, the valve seat opening 360 is
closed by the floating closure member 340, preventing further exchanges of fluids
between the washing tub 107 and the discharge duct 310. The floating closure member
340 is advantageously shaped in such a way that its upper portion matches the valve
seat opening 360 when abutting against the valve seat 350.
[0049] In order to reduce the amount of air which may concentrate in the upper portion of
the discharge duct 310 between the lower side of the valve seat 350 and the floating
closure member 340, and which may elastically oppose to the closure of the valve 330,
an air passage coupling the discharge duct 310 with the washing tub 107 is advantageously
provided. The presence of such air passage allows air trapped in the discharge duct
310 to be discharged in the washing tub 107 during the closure of the valve. According
to an embodiment of the present invention, an intercepting member is provided, arranged
in such a way to avoid a liquid flow exiting the air passage (e.g. coming from the
discharge system 300 through the air passage and directed toward the drum 110) hits
the drum 110 (and, via the holes provided in the latter, the laundry 112 contained
therein). According to an embodiment of the present invention, this is obtained by
arranging the intercepting member in such a way to intercept said liquid flow.
[0050] Figure 4 is a simplified cross-sectional view of the drum-washing tub-discharge system
assembly according to an embodiment of the present invention.
[0051] According to this embodiment of the invention, the air passage connecting the discharge
duct 310 with the washing tub 107 comprises an air pipe 410, extending along a direction
B substantially parallel to the axis of the discharge hole 210. The air pipe 410 has
a top end 412 with an opening 415 located in the washing tub 107 interior, and a bottom
end 417 with an opening 420 facing the discharge duct 310 interior. In the advantageous
embodiment of Fig. 4, the opening 420 faces a hole 425 provided on the valve seat
350, for example at a border portion thereof. In this way, air located within the
discharge duct 310 may advantageously pass through the hole 425, go up the air pipe
410, and then reach the washing tub 107 interior through the opening 415. According
to this embodiment of the present invention, an intercepting member 430 is provided
in correspondence to the top end 412 of the air pipe 410, so as to intercept liquid
flows coming from the discharge duct 310 through the air passage and directed toward
the drum 110.
[0052] According to an embodiment of the present invention, the intercepting member 430
comprises a roof or a shield or a deflector element having a deflector surface 430a
which extends transversally, preferably substantially perpendicularly, to the direction
B. Advantageously, the presence of such roof or shield or deflector element avoids
that washing products enter the air pipe 410 (because of gravity) and discharge into
the discharge duct 310.
[0053] Other configurations are also contemplated, wherein the intercepting member 430 has
different orientations, provided that said orientations allow the intercepting member
430 to intercept liquid flows coming from the discharge duct 310 and directed toward
the drum 110. According to these embodiments of the invention, the intercepting member
430 is arranged in such a way that if washing liquid, water, and/or foam located in
the discharge duct 310 passes through the air passage (in this embodiment of the invention,
goes up the air pipe 410), instead of reaching the drum 110 (and dirtying the laundry
contained therein), this washing liquid, water, and/or foam is advantageously deflected
away from the drum,
e.g., toward the bottom of the washing tub 107.
[0054] According to another embodiment of the present invention, instead of comprising a
roof or a shield or a deflector element, the intercepting member 430 may advantageously
comprise one or more protruding elements shaped and positioned in such a way to "break"
the liquid flow coming from the air passage into a plurality of smaller flows which
are not capable of reaching the drum 110.
[0055] In order to minimize the amount of washing liquid that might pass from the washing
tub 107 into the discharge duct 310 during the washing operations, the openings 415,
420 and the hole 425 have sufficiently small sizes.
[0056] Advantageously, as illustrated in Figure 4, both the air pipe 410 and the intercepting
member 430 are integral to (i.e. made in a single-piece construction with) the washing
tub 107. However, similar considerations apply if the air pipe 410 and/or the intercepting
member 430 are separated pieces attached to the washing tub 107, for example through
snap-fit engagements, pins, welding, or glue.
[0057] According to another embodiment of the present invention, instead of having a simple
hole (
i.e., the hole 425 of Figure 4), the valve seat 350 directly comprises a respective air
pipe, which extends parallel to the air pipe 410 (
e.g., substantially parallel to the direction B). For example, in the embodiment of the
invention illustrated in Figure 5, the valve seat 350 is provided with an air pipe
510 (
e.g., integral to the valve seat 350) adapted to be coaxially fitted inside the air pipe
410. In this case, the resulting air passage connecting the discharge duct 310 with
the washing tub 107 is more reliable, being less prone to blockings due to possible
misalignments between the valve seat 350 and the washing tub 107. An isometric view
of the air pipe 510 located on the valve seat 350 according to an embodiment of the
present invention is also visible in Figure 3.
[0058] According to another advantageous embodiment of the present invention (not illustrated
in enclosed figures), the washing tub 107 does not include the air pipe 410, and the
air passage connecting the discharge duct 310 with the washing tub 107 comprises instead
the air pipe 510, arranged in such a way to directly face the internal of the tub
or to face or to pass through a hole provided on the washing tub 107. In this case,
the intercepting member adapted to intercept liquid flows coming from the discharge
duct 310 and directed toward the drum 110 may be directly arranged on the valve seat
350 (
e.g., integral to the air pipe 510) or arranged on the washing tub 107, (
e.g., protruding from a wall thereof).
[0059] According to a further embodiment of the present invention (not illustrated in the
figures), the air passage connecting the discharge duct 310 with the washing tub 107
does not include any dedicated air pipe, and comprises instead a simple hole provided
on the valve seat 350, which puts in communication the internal of the tub and the
discharge duct 310.
[0060] In a further advantageous embodiment, the air passage connecting the discharge duct
310 with the washing tub 107 comprises a hole provided on the valve seat 350, facing
a further hole provided in the washing tub 107. In this case as well, the intercepting
member may be directly arranged on the valve seat 350 (
e.g., protruding therefrom) or arranged on the washing tub 107 (
e.g., protruding from a wall thereof).
[0061] Naturally, in order to satisfy local and specific requirements, a person skilled
in the art may apply to the solution described above many logical and/or physical
modifications and alterations.
[0062] For example, although the embodiments of the invention described above make reference
to a single air passage in parallel to the discharge hole, similar considerations
apply in case more than one air passages connect the discharge duct with the washing
tub.
[0063] Furthermore, even if in the description reference has been mainly made to an air
passage crossing the valve seat of the floating valve, the concepts of the present
invention apply as well in case the air passage connecting the discharge duct with
the washing tub is provided on a portion of the discharge duct itself, for example
provided with a respective hole or a respective air pipe overlapped with a corresponding
hole (or coaxially fitted in a corresponding air pipe) provided in the washing tub.
[0064] Moreover, even if in some of the described embodiments reference has been made to
an air passage comprising an air pipe extending substantially parallel to the axis
of the discharge hole of the washing tub, similar considerations apply if the air
pipe has a different orientation, and/or includes bends.
1. A washing machine (100) comprising:
- a washing tub (107) in which washing liquid may be loaded;
- a perforated drum (110) rotatably accommodated in the washing tub (107) for containing
laundry to be washed;
- a discharge system (300, 310, 330) fluidly connected to the washing tub (107) and
adapted to selectively discharge washing liquid from the washing tub (107), and
- a valve (330), placed between the washing tub (107) and the discharge system (300,
310, 330), comprising:
a) a valve seat (350) through which liquid can pass from the washing tub (107) to
the discharge system (300, 310, 330),
b) a closure member (340) movable with respect to the valve seat (350) from a closing
position, in which said closure member (340) abuts against the valve seat (350), impeding
the flow of washing liquid from the washing tub (107) to the discharge system (300,
310, 330), to an open position in which said closure member (340) is at least partially
spaced apart from the valve seat (350), allowing the flow of washing liquid from the
washing tub (107) to the discharge system (300, 310, 330);
wherein the washing machine (100) further comprises an air passage (410, 425; 510)
fluidly connecting said discharge system (300, 310, 330) and said washing tub (107)
for allowing the passage of at least air from the discharge system (300, 310, 330)
to the washing tub (107),
characterized in that
the washing machine (100) further comprises an intercepting member (430) arranged
to prevent a liquid flow exiting said air passage (410, 425; 510) from hitting said
drum (110).
2. The washing machine of claim 1, wherein said intercepting member (430) is arranged
in such a way to intercept a liquid flow exiting said air passage (410, 425; 510)
and directed toward the drum (110).
3. The washing machine (100) of claim 1 or 2, wherein the intercepting member (430) is
arranged to deflect away from the drum (110) a liquid flow exiting said air passage
(410, 425; 510).
4. The washing machine (100) of claim 1 or 2 or 3, wherein the intercepting member (430)
comprises a deflecting surface (430a) displaced transversally, preferably perpendicularly,
to the longitudinal axis of said air passage (410, 425; 510).
5. The washing machine (100) of any one among the preceding claims, wherein said air
passage (410, 425; 510) comprises an air pipe (410; 510) extending substantially parallel
to the longitudinal axis of the discharge hole (210).
6. The washing machine (100) of claim 5, wherein said air pipe (410; 510) comprises a
first air pipe (410) having a top end (412) with a first opening (415) located in
the washing tub (107) interior and having a bottom end (417) with a second opening
(420) facing the discharge system (300, 310, 330).
7. The washing machine (100) of claim 6, wherein the intercepting member (430) is placed
in proximity of the top end (412) of the first air pipe (410).
8. The washing machine (100) of claim 6 or 7, wherein said first air pipe (410) is integral
with the washing tube (107).
9. The washing machine (100) of claim 8, wherein the valve seat (350) includes a hole
(425) facing said second opening (420).
10. The washing machine (100) of claim 8 or 9, wherein said air passage (410, 425; 510)
comprises a second air pipe (510) integral with the valve seat (350) and coaxially
fitted inside the first air pipe (410).
11. The washing machine (100) of claim 5 or 6 or 7, wherein said first air pipe (410)
is integral with the valve seat (350).
12. The washing machine (100) of any one among claims 1 to 4, wherein said air passage
comprises a hole (425) located on said valve seat (350).
13. The washing machine (100) of any one among the preceding claims, wherein the intercepting
member (430) is integral with the washing tub (107).