U.S. patent application number 16/489553 was filed with the patent office on 2020-01-09 for an assembly for dispensing washing agents for a washing machine, in particular a dishwasher.
This patent application is currently assigned to ELBI INTERNATIONAL S.p.A.. The applicant listed for this patent is ELBI INTERNATIONAL S.p.A.. Invention is credited to Giuseppe MARONE.
Application Number | 20200008646 16/489553 |
Document ID | / |
Family ID | 59579829 |
Filed Date | 2020-01-09 |
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United States Patent
Application |
20200008646 |
Kind Code |
A1 |
MARONE; Giuseppe |
January 9, 2020 |
AN ASSEMBLY FOR DISPENSING WASHING AGENTS FOR A WASHING MACHINE, IN
PARTICULAR A DISHWASHER
Abstract
Assembly (1) for dispensing washing agents in the washing
chamber (C) of a washing machine, including an integrated
dispensing device for washing agents (2), comprising a body (2a)
which is intended to be mounted through an opening of a sheet-like
wall (F) which delimits the washing chamber (C). The assembly (1)
further comprises a reservoir (3) for liquid detergent which may be
removably coupled to the body (2a) of the device for dispensing
washing agents (2), and which may be positioned on the side of the
device for dispensing washing agents (2) intended to face the
washing chamber (C). The reservoir has a holding chamber (3d) for
liquid detergent able to communicate with the outside of the
reservoir (3) through at least one outlet opening (12b) for
dispensing liquid detergent and an actuator assembly (21, 22, 23,
24) to control the dispensing of liquid detergent from the
reservoir (3).
Inventors: |
MARONE; Giuseppe; (NICHELINO
(Torino), IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ELBI INTERNATIONAL S.p.A. |
TORINO |
|
IT |
|
|
Assignee: |
ELBI INTERNATIONAL S.p.A.
TORINO
IT
|
Family ID: |
59579829 |
Appl. No.: |
16/489553 |
Filed: |
March 6, 2018 |
PCT Filed: |
March 6, 2018 |
PCT NO: |
PCT/IB2018/051428 |
371 Date: |
August 28, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A47L 15/4251 20130101;
A47L 15/4409 20130101; A47L 15/4463 20130101; A47L 15/4472
20130101; A47L 15/4418 20130101 |
International
Class: |
A47L 15/44 20060101
A47L015/44; A47L 15/42 20060101 A47L015/42 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 7, 2017 |
IT |
102017000025267 |
Claims
1. An assembly for dispensing washing agents into a washing chamber
(C) of a washing machine, in particular a dishwasher machine (WD),
including an integrated device for dispensing washing agents (2),
comprising a body (2a) intended to be mounted in an opening of a
sheet-like wall (F) that delimits the washing chamber (C), wherein
in said body are arranged at least one receptacle and at least one
actuator to dispense a washing agent, the assembly (1) being
characterized by further comprising a reservoir (3) for liquid
detergent that may be removably coupled to the body (2a) of the
device for dispensing washing agents (2), and that may be
positioned on the side of the device for dispensing washing agents
(2) intended to face towards the washing chamber (C), said
reservoir having a holding chamber (3d) for the liquid detergent
capable of communicating with the outside of the reservoir (3)
through at least one outlet opening (12b) for dispensing the liquid
detergent, and actuating means (21, 22, 23, 24) for controlling the
liquid detergent to be dispensed from the reservoir (3), said
reservoir being distinct from said receptacle and said actuating
means being distinct from said actuator.
2. The assembly according to claim 1, wherein the reservoir (3) may
be hingedly connected to the body (2a) of the device for dispensing
washing agents (2) and, when the reservoir is connected to the body
(2a) of the device for dispensing washing agents (2), the reservoir
is capable of assuming a working position, wherein the reservoir is
substantially horizontal with respect to the body (2a) of the
device for dispensing washing agents (2), and a raised
position.
3. The assembly according to claim 2, wherein the body (2a) of the
device for dispensing washing agents (2) comprises a receptacle for
collecting a rinsing agent, and an inlet funnel (8) for loading the
rinsing agent arranged on a front of the body (2a) of the device
for dispensing washing agents (2), and wherein in the working
position the reservoir (3) closes said inlet funnel (8) as a
cap.
4. The assembly according to claim 2, wherein the reservoir (3) is
connectable to the body (2a) of the device for dispensing washing
agents (2) by means of a pair of opposite side pins (2p) arranged
on one of said reservoir (3) and body (2a) of the device for
dispensing washing agents (2) and snap-fittable within
corresponding seats formed on the other of said reservoir (3) and
body (2a) of the device for dispensing washing agents (2), and by
means of a central pin (2q) arranged on one of said reservoir (3)
and body (2a) of the device for dispensing washing agents (2) and
snap-fittable within a corresponding seat formed on the other of
said reservoir (3) and body (2a) of the device for dispensing
washing agents (2).
5. The assembly according to claim 2 wherein the reservoir (3)
comprises a body (3a) having a thinner connection part (3b) for
connection to the device for dispensing washing agents (2) which in
the working position is superimposed to the body (2a) of the device
for dispensing washing agents (2), and a thicker holding part (3c)
in which the holding chamber (3d) for the liquid detergent is
formed.
6. The assembly according to claim 5, wherein in the working
position the holding part (3c) of the body (3a) of the reservoir
(3) is intended to be received in a recess (F1) formed on the
sheet-like wall (F) of the washing chamber (C).
7. The assembly according to claim 1, comprising a removable cap
(11) mounted on the reservoir (3), said outlet opening (12b) being
formed through the cap (11).
8. The assembly according to claim 1, further comprising dispensing
means (16, 30) arranged within the reservoir (3) and configured to
cause the liquid detergent to be dispensed out through the outlet
opening (12b), said dispensing means (16) being controlled by
contactless force transmission by the actuating means (21, 22, 23,
24).
9. The assembly according to claim 8, wherein the dispensing means
(16, 30) may be removed from the reservoir (3), and in particular
they are positioned in a removable cap (11) of the reservoir
(3).
10. The assembly according to claim 8, wherein said dispensing
means comprise a piston (16) movable within the holding chamber
(3d) of the reservoir (3) and capable of assuming an advanced
end-of-stroke position, in which the piston (16) engages a seat
(14d) formed at the outlet opening (12b) and blocks fluid
communication between the holding chamber (3d) and the outside of
the holding chamber (3d), and a retracted end-of-stroke position,
in which the piston (16) is removed from the seat, wherein a
variable volume working chamber (14e) capable of communicating with
the holding chamber (3d) is defined between the piston (16) and the
seat (14d); and non-return valve means (30) arranged at the outlet
opening (12b) and downstream of the seat (14d), said non-return
valve means (30) being open or closed when the difference between a
fluid pressure upstream thereof and a fluid pressure downstream
thereof is higher or lower than a predetermined value,
respectively; wherein during the stroke of the piston (16) from the
advanced end-of-stroke position to the retracted end-of-stroke
position the liquid flows from the holding chamber (3d) to the
working chamber (14e), and during the stroke of the piston (16)
from the retracted end-of-stroke position to the advanced
end-of-stroke position the liquid is dispensed out from the working
chamber (14e) through the outlet opening (12b).
Description
[0001] The present invention relates to an assembly for dispensing
washing agents in the washing chamber of a washing machine, in
particular a dishwasher machine.
[0002] More specifically, the object of the invention is an
assembly including [0003] an integrated device for dispensing
washing agents, comprising a body intended to be mounted in an
opening of a sheet-like wall that delimits the washing chamber,
wherein in said body are made at least one receptacle and at least
one actuator to dispense a washing agent, [0004] the assembly being
characterized by further comprising [0005] a reservoir for liquid
detergent that may be removably coupled to the body of the device
for dispensing washing agents and may be positioned on the side of
the device for dispensing washing agents intended to face the
washing chamber, said reservoir having a holding chamber for the
liquid detergent capable of communicating with the outside of the
reservoir through at least one outlet opening for dispensing the
liquid detergent into the washing chamber, and [0006] actuating
means for controlling the liquid detergent to be dispensed from the
reservoir, said reservoir being distinct from the receptacle and
said actuating means being distinct from said actuator.
[0007] In the assembly according to the invention, the reservoir
may be sized with adequate capacities to contain and distribute
relative amounts without necessarily having to load it at each
washing cycle, as currently occurs with normal commercial
dishwashers.
[0008] At the same time, the problems of washability of the entire
volume and of the entire surface that come into contact with
detergents are overcome. A characteristic of liquid detergents
which is of little use in automatic dosing is that, after a certain
time of exposure to the air or after disuse, they tend to change
their viscosity until they reach the solid state. In this case,
having an object with the parts that come into contact with the
detergent being completely washable and with an easily accessible
internal volume solves the problems of restoring the functions.
[0009] The reservoir is removable, and therefore may be washed in
its entirety, for example under a tap of running water, so as to
remove any residual liquid detergent which for any reason has
solidified therein.
[0010] In this regard, it is particularly advantageous to have a
dispensing system inside the reservoir, configured to cause liquid
detergent to be dispensed through the outlet opening and controlled
without contact by the actuator means, which is removable from the
reservoir, for example positioned in a removable cap.
[0011] According to one embodiment, the reservoir may be hingedly
connected to the body of the device for dispensing washing agents
and, when the reservoir is connected to the body of the device for
dispensing washing agents, the reservoir may assume a working
position, wherein the reservoir is substantially horizontal with
respect to the body of the device for dispensing washing agents and
in a raised position.
[0012] Generally, the body of the integrated washing agent
dispensing device comprises a receptacle adapted to hold a rinsing
agent, and an inlet funnel for loading the rinsing agent, arranged
on the front of the body of the integrated washing agent dispensing
device. In this case, advantageously, in the working position, the
reservoir closes said inlet funnel in the form of a cap.
[0013] According to one particularly preferred embodiment, the
reservoir is connectable to the body of the device for dispensing
washing agents by means of a pair of opposite side pins arranged on
one of said reservoir and body of the device for dispensing washing
agents and snap-fittable within corresponding seats formed on the
other of said reservoir and body of the device for dispensing
washing agents, and by means of a central pin arranged on one of
said reservoir and body of the device for dispensing washing agents
and snap-fittable within a corresponding seat formed on the other
of said reservoir and body of the device for dispensing washing
agents.
[0014] The reservoir may comprise a body having a thinner
connection part for connection to the device for dispensing washing
agents which, in the working position, is superimposed on the body
of the device for dispensing washing agents, and a thicker holding
part wherein the holding chamber for the liquid detergent is
formed.
[0015] In this case, in the working position, the holding part of
the body of the reservoir may be intended to be housed in a recess
formed on the sheet-like wall of the washing chamber.
[0016] Further features and advantages of this invention will
become more apparent from the detailed description that follows,
provided purely by way of non-limiting example with reference to
the accompanying drawings, wherein:
[0017] FIG. 1 is a perspective view of a dishwasher machine
provided with an assembly for dispensing washing agents according
to the present invention;
[0018] FIGS. 2 and 3 are perspective views, essentially from the
front, of an assembly installed on the machine of FIG. 1;
[0019] FIG. 4 is a perspective view, essentially from the rear, of
the assembly of FIGS. 2 and 3;
[0020] FIGS. 5 and 6 are perspective views of the assembly only,
with the reservoir respectively in the working position and in the
raised position;
[0021] FIGS. 7 and 8 are perspective views, respectively front and
rear, of the assembly without the reservoir;
[0022] FIGS. 9 and 10 are schematic and sectional views of a
reservoir cap, in two different operating positions;
[0023] FIG. 11 is a perspective view of the cap of FIGS. 9 and
10;
[0024] FIG. 12 is a detailed view of the reservoir, with the cap
installed;
[0025] FIGS. 13 and 14 are perspective views of components of the
cap.
[0026] FIG. 1 collectively indicates a dishwasher at WD. Such
machine comprises a housing A, essentially parallelepiped in shape,
provided with a front opening B through which the washing chamber C
of the machine may be accessed.
[0027] At the front opening B there is associated a door D
oscillatable relative to the housing A of the machine WD about an
essentially horizontal axis, indicated at E-E in FIG. 1.
[0028] On the side facing the washing chamber C, the door D has a
sheet-like wall F, typically of sheet metal. In this wall F an
opening is made, wherein an assembly for dispensing washing agents
is mounted, collectively indicated at 1 in the drawings.
[0029] With reference in particular to FIGS. 2 to 8, the combined
unit 1 comprises an integrated device for dispensing washing agents
indicated collectively at 2, and a reservoir for liquid detergent
indicated collectively at 3.
[0030] In the illustrated embodiment, the integrated dispensing
device 2 comprises a body 2a made of molded plastic material,
wherein in a manner known per se a first release device 4 is made
for dispensing a detergent, in particular in powder form, and an
adjacent second release device 5 for dispensing a liquid rinsing
agent (see in particular FIGS. 6 and 7).
[0031] The detergent release device 4 comprises a receptacle for
the detergent (not shown in the figures) essentially in the form of
a basin, to which a cover 7 is associated. Such cover may be
rotatably mounted, or movably coupled to the body 2a, or otherwise
in a rotary-translatable manner.
[0032] The release device 5 for the rinsing agent is likewise of a
type known per se. It comprises a receptacle (not visible in the
figures) suitable to receive a quantity of rinsing agent
corresponding to a plurality of doses. The figures show an inlet
funnel 8 on the front of the integrated dispensing device 2, which
serves to top up the rinsing agent in the corresponding receptacle.
The dosed dispensing of the rinsing agent to the washing chamber C
of the dishwasher machine WD is, in a manner known per se,
controlled by means of a normally closed shut-off valve interposed
on a duct capable of putting the receptacle in communication with
such washing chamber, and opening at an outlet opening 9 (FIG. 3)
on the front of the integrated dispensing device 2.
[0033] The dispensing of the detergent and the rinsing agent may be
controlled by means of a single electrically controlled actuator
device, indicated collectively at 10 in FIGS. 4 and 8.
[0034] Such solution is particularly suitable, but the adoption
thereof is not limiting: alternatively, solutions of the type with
two separate actuators may also be adopted.
[0035] The reservoir 3 is removably coupled to the body 2a of the
integrated dispensing device 2. In particular, the reservoir 3
comprises a body 3a made of plastic material hinged to the body 2a
of the integrated dispensing device 2. The reservoir 3 may be
composed of two parts coupled to one another, for example by means
of thermal welding methods, but may also be made in a single part,
for example by means of blowing methods.
[0036] The reservoir 3 in the illustrated embodiment is therefore
rotatably coupled to the body 2a of the integrated dispensing
device 2. In particular, the body 2a of the reservoir 3 has a
thinner connection part 3b, for connecting to the device for
dispensing washing agents 2, and a thicker holding part 3c, wherein
a holding chamber 3d for the liquid detergent (visible in FIGS. 9
and 10) is formed. On the connecting part 3b of the reservoir 3
there is formed a cap formation 3f, the function of which will be
described hereinafter.
[0037] The connecting part 3b has two parallel appendages 3e, the
distal ends of which have respective recesses adapted to be engaged
by respective pegs or pins 2p arranged on the body 2a of the
integrated device 2 (visible for example in FIG. 7). This
arrangement is not limiting, since the pins may be arranged on the
body of the reservoir and the corresponding recesses may be formed
on the body of the integrated device 2.
[0038] The reservoir 3 is therefore capable of assuming, with
respect to the integrated dispensing device 2, an angular working
position shown in FIGS. 1 and 5, wherein the reservoir 3 is
substantially horizontal with respect to the body 2a of the device
for dispensing washing agents 2, the connecting part 3b is
superimposed on the body 2a of the device for dispensing washing
agents 2, and the cap formation 3f of the reservoir 3 closes the
inlet funnel 8 for the rinsing agent; and a raised angular position
shown in FIGS. 1, 3 and 6, wherein the connecting part 3b of the
reservoir 3 is raised with respect to the body 2a of the dispensing
device 2. In the raised position of the reservoir 3, it is possible
to refill the rinsing agent through the inlet funnel 8.
[0039] According to an alternative embodiment, not shown, the
reservoir 3 the cap function for the inlet funnel of the rinsing
agent may be absent. In this case it is necessary to provide the
inlet funnel of the rinsing agent with its own cap.
[0040] In the working position, the holding part 3c of the body 3a
of the reservoir 3 is intended to be housed in a recess F1 formed
on the sheet-like wall of the washing chamber, adjacent to the
integrated dispensing device 2.
[0041] As shown in FIG. 7, the pegs or pins 2p are configured to
snap-fit in the respective hollows formed on the connection part 3b
of the reservoir 3. Such configuration may be made, for example, by
providing for the pins 2p to be arranged to slide in respective
guides and to be pushed by springs towards the engagement position
(in the laterally external direction). Naturally, other
configurations are possible.
[0042] On the body 2 of the integrated device 2, a further snap peg
or pin 2q may be provided, in a central position, which is adapted
to engage a corresponding seat 3q (see FIG. 2) to block the
reservoir 3 in the horizontal working position. Alternatively, the
pin could be arranged on the cover 3 and the respective seat on the
body of the integrated dispensing device.
[0043] Although advantageous, the configuration according to which
the reservoir 3 is rotatable with respect to the pins 2p is not
limiting. For example, the reservoir could be configured for a
removable assembly on the body 2a of the integrated device 2, but
without being able to rotate with respect to the body of the
integrated dispensing device.
[0044] At a filling mouth 3g of the reservoir 3, a removable cap 11
is sealingly mounted, represented in greater detail in FIGS. 9-14.
The cap 11 comprises a head 12 and a hollow drum 14, which extends
axially from the head 12 into the holding chamber 3d. A gasket 15
is arranged on the side of the cap 11 facing the drum 14 adapted to
be compressed between the head 12 of the cap 11 and a wall of the
reservoir 3 around the mouth 3g when the cap is mounted on the
reservoir. Through the head 12 of the cap, a plurality of outlet
openings or through-holes 12b are formed. The closure of the cap
may be made by screw or by bayonet as in the illustrated example,
by means of radial projections 12a formed on the perimeter of the
head 12 of the cap which engage with corresponding grooves formed
on the perimeter of the filling mouth 3g of the reservoir 3.
[0045] The drum 14 comprises a radially outer tubular wall 14a, on
which a pair of diametrically opposed longitudinal slots 14b are
formed, and a radially inner tubular wall 14c, coaxial with the
radially outer tubular wall 14a and having a longitudinal extension
lower with respect thereof. The cavity inside the radially inner
tubular wall 14c is in communication with the outlet openings 12b
formed on the head 12 of the cap 11.
[0046] The end of the drum 14 far from the head 12 of the cap is
inserted in a centering collar formation 3h made in the bottom of
the reservoir 3.
[0047] Inside the drum 14 a piston 16 is mounted in a guided
manner. The piston 16 comprises a guide part 16a, slidably inserted
inside the radially outer tubular wall 14a of the drum 14 and
provided with guide protrusions 16b inserted in the slots 14b, and
a piston end portion 16c provided with longitudinal grooves 16d on
the side surface thereof. At the top of the piston end portion 16c
is positioned a diaphragm 17 made of a deformable material, e.g.
elastomeric material. The diaphragm 17 is fixed to the piston end
portion 16c at its center, while it is free to flex
peripherally.
[0048] At an advanced end-of-stroke position of the piston 16, the
piston end portion 16c is designed to abut against a seat 14d
formed on the inner side of the radially inner tubular wall 14c.
The seat 14d is positioned at a predetermined distance from the
free end of the radially inner tubular wall 14c. Between the seat
14d and the free end of the radially inner tubular wall 14c, a
chamber 14e is thus defined as being surrounded by a continuous
wall, i.e. without side openings.
[0049] A permanent magnet 18 is fixed to the piston 16, positioned
in such a way as to have a polarity oriented parallel to the
direction of movement of the piston 16.
[0050] The permanent magnet 18 is designed to interact without
contact with a pair of permanent control magnets 21, 22 arranged
outside the reservoir 3, on the other side of the bottom wall
thereof when the reservoir 3 is mounted in the working position.
Other systems based on force transmission without contact are
conceivable, in particular, systems based on electromagnets.
[0051] The control magnets 21, 22 are arranged in such a way as to
have a polarity oriented parallel to the direction of movement of
the piston 16. One of them, 21, hereinafter referred to as the
retracting magnet, points towards the magnet 18 a pole opposite the
pole which the magnet 18 directs towards the magnet 21. The other,
22, hereinafter referred to as the advancing magnet, directs
towards the magnet 18 a pole with an identical sign as that of the
pole which the magnet 18 directs towards the magnet 22.
[0052] As can be seen in FIGS. 7 and 8, the control magnets 21, 22
are carried by a support member 23 rotatable about an axis y
orthogonal to the disposition plane of the device 2. With respect
to this support member 23, the magnets 21 and 22 occupy angularly
distinct positions, in particular, diametrically opposed. However,
such provision is not limiting, as a configuration is also
foreseeable wherein the magnets may be alternately translated.
[0053] Preferably, the support member 23 is mounted on a structure
integrally formed with the body of the integrated device 2. The
support member 23 receives the motion from an actuator 24, for
example, by means of gearing between a sprocket keyed on an output
shaft of the actuator and a peripheral toothing of the support
member 23. However, such arrangement is not limiting, as a
configuration is also foreseeable wherein the actuator is a linear
actuator. Also, the actuator 24 is supported by a structure made
integrally with the body of the integrated device 2.
[0054] A unidirectional non-return valve device 30 is positioned at
the head 12 of the cap. This device 30 is positioned in the cavity
delimited by the radially inner side wall 14c, between the seat 14d
and the outlet openings 12b. The non-return valve device 30 is
conventionally provided with resilient means which stress the
shutter into a closed position. The valve device 30 is therefore
configured to be open or closed when the difference between a fluid
pressure upstream thereof (i.e. in the chamber 14e) and a fluid
pressure downstream thereof (i.e. at the outlet openings 12b) is
respectively greater than or less than a predetermined value
(substantially determined by the resilient means).
[0055] In the retracted end-of-stroke position shown in FIG. 9, the
piston 16 is substantially resting against the bottom wall of the
reservoir 3 and is held in such position by the magnetic attraction
between the magnet 18 of the piston 16 and the retracting magnet 21
which are positioned opposite each other.
[0056] As a result of a control signal sent by a control unit to
the actuator 24, the actuator 24 controls the rotation of the
support member 23 so as to bring the advancing magnet 22 in front
of the magnet 18 of the piston 16 (FIG. 10).
[0057] Because of the magnetic repulsion between the magnet 18 of
the piston 16 and the advancing magnet 22, the piston 16 advances
towards the seat 14d with the diaphragm 17. When the diaphragm 17
starts to engage the free end of the radially inner tubular wall
14c, the compression of the liquid detergent inside the chamber 14e
causes the opening of the non-return valve device 30 and therefore
the dispensing of the liquid detergent into the washing chamber C
of the machine. The movement of the piston ends when the diaphragm
17 reaches the seat 14d. At the end of the piston's advancement,
the non-return valve 30 is closed, determined by its resilient
means. Overall, a volume of liquid detergent is then dispensed
substantially equal to the maximum volume of the chamber 14e
upstream of the seat 14d (determined by the distance between the
seat 14d and the free end of the radially inner tubular wall
14c).
[0058] As a result of another control signal sent by a control unit
to the actuator 24, the actuator 24 controls the rotation of the
support member 23 so as to bring the retracting magnet 21 in front
of the magnet 18 of the piston 16 (FIG. 9).
[0059] Due to the magnetic attraction between the magnet 18 of the
piston 16 and the retracting magnet 21, the piston 16 retracts with
the diaphragm 17 towards the retracted end-of-stroke position. The
closure of the non-return valve device 30, which occurred at the
end of the advancement phase of the piston, prevents the water
circulating in the washing chamber C of the machine from
penetrating into the reservoir 3; at the same time, it prevents the
piston from sucking into the reservoir the detergent pushed forward
by the previous movement. At the beginning of the retracting
movement, the diaphragm 17 flexes peripherally as a result of
contact with the radially inner tubular wall 14c and/or the thrust
of the liquid into the grooves 16d on the piston end portion 16c,
allowing the liquid detergent present in the holding chamber 3d to
reach the chamber 14e adjacent to the seat 14d. The diaphragm 17
returns to its undeformed configuration when the piston 16 is
retracted by an amount such as to bring the diaphragm 17 out of the
chamber 14e adjacent to the seat 14d. The movement of the piston 16
ends when the bottom wall of the reservoir is reached. To prevent
the piston from impacting the bottom wall of the reservoir in a
noisy manner, a chamber 3m is provided at the bottom of the
reservoir (delimited at the top by a dotted line in FIG. 9) inside
of which the liquid resists the retraction of the piston. This is
ensured by a side wall around the chamber 3m (in this case provided
by one end of the drum), wherein calibrated passages (not shown in
the figure) are formed, which allow the liquid in the chamber 3m,
compressed by the piston 16 during the retracting movement of the
latter, to escape into the holding chamber 3d of the reservoir.
[0060] With the retraction of the piston, a new quantity of liquid
detergent is loaded into the chamber 14e ready to be dispensed in a
subsequent movement.
[0061] Generally, the volume of detergent needed for a machine
cycle may reach 40/50 cm.sup.3, so the movement of the piston
which, at each cycle, dispenses only a small part of the volume
(for example 2/3 cm.sup.3) must be repeated in a series of pulses
until the expected quantity is reached.
[0062] Although advantageous for the washability of the reservoir,
the configuration wherein the piston and the valve device are
positioned inside the removable cap is not limiting. For example,
it is possible to conceive of an embodiment wherein such components
are partially or completely positioned outside the cap. The
function of supporting the components being provided in this case
by the parts formed in the body of the reservoir, the cap would
only maintain the closing function.
[0063] Naturally, without altering the principle of the invention,
the embodiments and the details of construction may vary widely
with respect to those described and illustrated purely by way of
non-limiting example, without thereby departing from the scope of
the invention as defined in the appended claims.
* * * * *