[0001] This invention relates to a liquid detergent and additive metering and distributing
device for a washing machine, particularly for a laundry washing machine for domestic
use.
[0002] Already known are laundry washing machines provided with a liquid detergent and additive
distributor, comprising a reservoir for containing said liquids disposed in the lower
portion of the machine and associated with at least one metering chamber located therebelow
and connected thereto through automatic valve means adapted to permit or to interrupt
the gravity flow of said liquids from the reservoir to the metering chamber. The latter
is subdivided into two hermetically separated compartments by means of a flexible
diaphragm. One compartment is connected to the tub of the washing machine, whilst
the other is connected to the tub and to the water supply circuit, respectively so
as to be intermittently filled and emptied for displacing metered quantities of the
liquids towards the tub. The operation of this known metering and distributing device
is thus accomplished by means of hydraulically actuated control means. Although the
described device operates satisfactorily, it presents structural complications in
that it requires a three-way valve and an additional conduit for the water supply
as well as a hermetically closed separation by a diaphragm for providing the two separate
compartments within the metering chamber. Said three-way valve and/or said diaphragm
are liable to cause malfuncions due to wear during long-time use.
[0003] On the other hand, this embodiment does not allow for suitable utilization of the
free jet section customarily required for safety reasons.
[0004] It is an object of the present invention to provide a liquid detergent and additive
metering distributor for a washing machine which avoids the possible inconveniences
of the hydraulically operated system by making use of a free jet section provided
in the machine for obtaining the metering of said liquids and the introduction thereof
into the tub by pneumatic actuation.
[0005] In view of this object, the invention provides a distributor device comprising a
reservoir disposed in the lower portion of the machine and associated to at least
one metering chamber located therebelow, the connection between said reservoir and
said chamber being adapted to be closed by automatic vlave means, said chamber being
connected to the tub of the washing machine.
[0006] According to the invention, a device of this type is characterized in that said metering
chamber is connected to an air chamber provided with automatic valve means and associated
to a free jet section connected to the water supply circuit.
[0007] The characteristics of the invention will become evident from the following description
of an exemplary and nonlimiting embodiment with reference to the accompanying drawing.
[0008] The drawing shows in diagrammatic form a conventional laundry washing machine comprising
a washing tub 1, connected to which is the outlet of a detergent powder distributor
2 supplied with water from the water mains 3 through a solenoid valve 4, a free jet
section 5, and a conduit 6.
[0009] Disposed in the lower portion of the machine is at least one reservoir 7 for containing
liquid detergents and additives, said reservoir 7 containing a metering chamber 8.
[0010] The latter is connected to reservoir 7 through an automatic valve and is additionally
connected to distributor 2 through a conduit 10.
[0011] Metering chamber 8 is further connected to an air chamber 13 associated with free
jet section 5 through a further conduit 11 and an automatic valve 12. Air chamber
13 is also provided with an automatic venting valve 14.
[0012] The operation of the described device appears simple and evident. When the machine
is at rest, or during operating phases which do not require the introduction of liquid
detergents or additives into the tub, valve 9 is open, and metering chamber 8 is filled
with a metered quantity of the liquid from reservoir 7. In this situation, air chamber
13 is not under pressure, and valves 12 and 14 are open. If it is required to introduce
the metered liquid into the tub, the program unit (not shovm) of the machine causes
the water supply valve to be opened, so that the water from the water mains fills
air chamber 13 via free jet section 5.
[0013] The pressure generated thereby within air chamber 13 causes venting valve 14 to close
instantly, so that the air contained in chamber 13 is displaced towards metering chamber
8 through valve 12 and conduit 11.
[0014] The pressurized air causes valve 9 to close and the liquid contained in metering
chamber 8 to be displaced towards washin.g tub 1 through conduit 10 and distributor
2.
[0015] After the water has completely filled air chamber 13, valve 12 is closed by the hydraulic
pressure to prevent the water from entering conduit 11 and flowing into metering chamber
8.
[0016] Subsequently the water supplied from water mains 3 and passing through free jet section
5 is introduced into washing tub 1 through conduit 6 and distributor 2 for completeing
the required charge for the following washing or rinsing phase.
[0017] As soon as the water supply from the water mains stops, chamber 13 is emptied, whereupon
valves 12 and 14 open.
[0018] This results in a partial vacuum within metering chamber 8, causing valve 9 to open
so as to admit a further metered quantity of the liquid detergent or additive into
chamber 8.
[0019] According to the invention, the metering of the liquid and the introduction thereof
into the tub are thus accomplished by substantially pneumatic actuation, reducing
to a minimum the number of components which are moreover of extreme simplicity and
reliability.
[0020] The device according to the invention permits the eventual problem of regulating
the metered quantities of liquids to be solved in a simple manner. To this effect,
the immersion depth of conduit 10 into chamber 8 may be varied by employing a sliding
sleeve 15 at the inflow end of conduit 10.
[0021] Sleeve 15 is vertically displaceable by means for instance of a pull rod 16 actuated
by a lever or control knob 17 mounted at the front of the machine.
[0022] The device according to the invention thus accomplishes the stated objects and provides
the additional advantage that the liquids employed may be metered with high accuracy
independent of their density and viscosity.
1. A liquid detergent and additive me t erirg and distributing device for a washing
machine, comprising a reservoir disposed in the lower portion of the machine and associated
to at least one metering chamber located therebelow, the connection between said reservoir
and said chamber being adapted to be closed by automatic valve means, said chamber
being connected to the tub of the washing machine, characterized in that said metering
chamber (8) is connected to an air chamber (13) provided with automatic valve means
(12, 14) and associated to a free jet section (5) connected to the water supply circuit
(3).
2. A distributing device according to claim 1, characterized in that said air chamber
(13) is provided with first automatic valve means (12) adapted to establish communication
between said air chamber (13) and said metering chamber (8), and with second automatic
valve means (14) adapted to establish communication between said air chamber (13)
and ambient atmosphere.
3. A distributing device according to claim 1, characterized in that manual control
means (15, 16, 17) are provided for controlling the depth of immersion within said
metering chamber (8) of a conduit (10) connecting the latter to the washing tub of
the machine.