Water softener abstract
A dishwashing machine includes at least one additive distributor
for dispensing additive into a wash tub, a first electrically controlled
actuator for operating the distributor, a water softener for softening
water supplied to the wash tub, a regeneration circuit for regenerating
the water softener, a second electrically controlled actuator for
operating the regenerating circuit, and a programmer for controlling
the operation of the first and second actuators. The first and second
actuators are electrically connected in parallel to each other.
A single switch is controlled by the programmer for connecting the
parallelly connected first and second actuators to a power source
for at least one first time period and at least one second time
period longer than the first time period. The first and second actuators
have response times respectively shorter and longer than the first
time period, and the response time of the second actuator is less
than the second time period.
Water softener claimsI claim:
1. In a dishwashing machine including at least one additive distributor
for dispensing at least one dishwashing additive into a wash tub,
a first electrically controlled actuator for operating said distributor,
a water softener for softening water supplied to the wash tub, regeneration
means for regenerating said water softener, a second electrically
controlled actuator for operating said regeneration means, and programmer
means for controlling the operation of said machine including said
first and second actuators, the improvement comprising:
said first and second actuators being electrically connected in
parallel to each other;
single switch means, controlled by said programmer means, for connecting
the parallelly connected first and second actuators to a power source
for at least one first time period and at least one second time
period longer than said first time period; and
said first and second actuators having response times respectively
shorter and longer than said first time period, such that operation
of said single switch means by said programmer means for said first
time period will operate said first actuator to dispense said at
least one additive but will not operate said second actuator to
regenerate said water softener.
2. The improvement claimed in claim 1 wherein said response time
of said second actuator is less than said second time period, such
that operation of said single switch means by said programmer means
for said second time period will operate said second actuator to
regenerate said water softener.
Water softener description
BACKGROUND OF THE INVENTION
The present invention relates to an automatic dishwashing machine,
particularly of the domestic type, provided with a detergent distributor
and a distributor for another additive, such as a brightener or
bleach, and additionally provided with a water softener as well
as a hydraulic circuit for the regeneration of the water softener.
As is known, this type of water softener basically includes a decalcifier
having ion exchange resins through which passes water to be supplied
to the wash tub of the machine. The ion exchange resins of such
a decalcifier periodically must be regenerated, for example with
a brine solution. For such purpose, the decalcifier is connected
by means of a control valve to a salt container to be supplied with
a metered quantity of regeneration water.
The admission of detergent to the wash tub, the delivery of the
brightener thereto and the regeneration of the decalcifier are effected
at different times and for different periods during the cycle of
operation of the dishwashing machine. Accordingly, it is necessary
to provide a plurality of different actuators controlled by respective
controls, for example electrical controls, which in turn are controlled
by the programmer of the machine. Thereby, suitable control of the
operation of the distributors and the regeneration valve is achieved.
In order to reduce the number of actuators and to increase their
reliability, it has been proposed to provide a single distributor
for the detergent and additives, that is an integrated distributor
provided in a single supporting body and operated by a single actuator.
One such arrangement is disclosed in German DE-OS No. 33 04 037.
Particularly, by the use of a single memory mechanism, this distributor
delivers a metered quantity of brightener, such as bleach, only
after a closing gate of a compartment capable of accommodating a
dosage of detergent has been opened.
However, even with this type of distributor, the dishwashing machine
nevertheless must be provided with respective switches for controlling
separately the actuators responsible for the operation of the distributor
and for carrying out the regeneration of the decalcifier.
SUMMARY OF THE INVENTION
Accordingly, it is the object of the present invention to provide
an improved dishwashing machine of the above type wherein it is
possible to employ a single control element for controlling selectively,
by means of a minimum number of actuators, the delivery of detergent
to the wash tub, the delivery of other additives thereto, as well
as the regeneration of the water softener.
This object is achieved in accordance with the present invention
by the provision of a dishwashing machine including at least one
additive distributor for dispensing at least one dishwashing additive,
for example detergent, brightener, etc., into a wash tub, a first
electrically controlled actuator for operating the distributor,
a water softener for softening water supplied to the wash tub, regeneration
means for regenerating the water softener, a second electrically
controlled actuator for operating the regeneration means, and a
programmer for controlling the operation of the machine including
the first and second actuators. In particular accordance with the
present invention, the first and second actuators are electrically
connected in parallel to each other. A single switch is controlled
by the programmer and connects the parallelly connected first and
second actuators to a power source for at least one first time period
and at least one second time period longer than the first time period.
The first and second actuators have response times respectively
shorter and longer than the first time period, such that the operation
of the single switch by the programmer for the first time period
will operate the first actuator to dispense the at least one additive
but will not operate the second actuator to regenerate the water
softener. On the other hand, the response time of the second actuator
is less than the second time period, such that operation of the
single switch by the programmer for the second time period will
operate the second actuator to regenerate the water softener.
Accordingly, by appropriately designing the programmer, in a manner
generally known in the art, it is possible to control selectively
the various actuators for the regeneration of the decalcifier and
for controlling the distribution of the various additives by means
of a single control element. This makes it possible to improve the
reliability of the dishwashing machine.
BRIEF DESCRIPTION OF THE DRAWING
Other objects, features and advantages of the present invention
will be apparent from the following detailed description of a preferred
and nonlimiting embodiment thereof, with reference to the accompanying
drawing, wherein:
The single FIGURE is a schematic view of one embodiment of a dishwashing
machine according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The drawing illustrates schematically a dishwashing machine including
a wash tub 1. At the bottom of tub 1 is provided a sump for collecting
washing liquid which may be pumped by a drain pump 2 to a discharge
line during a draining phase of the cycle of operation of the machine.
Also illustrated is a recirculation pump 3 operable during a washing
phase of the cycle of operation of the machine to supply washing
liquid from the bottom of tub 1 to sprinkling vanes 4. These features
of the dishwashing machine are conventional.
The wash tub 1 is supplied with water from a water main via a supply
conduit 5 in which are arranged in series a charging valve 6 an
air break 7 and a water softener such as a decalcifier 8. The end
portion of conduit 5 may be formed in the manner disclosed in European
Patent Application EP-B No. 0022911. These features in themselves
are conventional.
The dishwashing machine also has a circuit for regeneration of
the active substances, for example ion exchange resins, of decalcifier
8. Such circuit includes a metering reservoir 9 and a salt (or other
regenerating substance) container 10. Reservoir 9 and air break
7 may be, for example, as disclosed in British Patent Application
GB-B No. 2063658. In particular, the bottom of reservoir 9 is
connected to the decalcifier 8 through a regeneration conduit 11
in which are arranged in series the salt container 10 and a valve
12 operated by an electrically controlled actuator 13. Suitably
mounted on the dishwashing machine, for example in a charging door
thereof (not shown) is provided a distributor 14 for the supply
of additives, such as a detergent and a brightener, to the wash
tub. It is contemplated that distributor 14 may be constructed in
the manner disclosed in the above German DE-OS No. 33 04 037. Thus,
distributor 14 includes a compartment 15 for a dosage of detergent
and provided with a closing gate, as well as a brightener distributor
16. The gate of compartment 15 is adapted to be opened by an actuator
17 for example an electromagnet or a thermistor device, when actuator
17 receives a brief control pulse, for example having a maximum
duration of several seconds. Distributor 16 is adapted to deliver
a metered quantity of the additional additive, for example brightener,
by the operation of actuator 17 but only when the latter receives
a brief control pulse after the gate of compartment 15 already has
been opened.
In particular accordance with the novel features of the present
invention, the actuators 13 17 are operated by a single control
element. More particularly, actuators 13 17 (the construction of
which would well be understood by one skilled in the art) are electrically
connected in parallel to each other as illustrated in the drawing,
and are connected across the terminals 18 19 of an electric power
supply by means of a single switch 20 (preferably of the electronic
type as would be understood by one skilled in the art) operated
by a programmer 21 of the dishwashing machine.
Actuator 13 is of the type having a delayed response time, and
can be as disclosed in Italian Patent Application No. 67094 A/80
filed Jan. 23 1980.
The single switch 20 is controlled by programmer 21 and is connected
in series with each of the parallel circuits of the actuators 13
17. Switch 20 is capable of predetermined operation by programmer
21 to connected the actuators 13 17 to the power source for at
least one first time period of relatively short duration and at
least one second time period of relatively long duration. It is
contemplated that actuators 13 17 have response times respectively
longer and shorter than the first time period of relatively short
duration. Thus, operation or closing of single switch 20 by programmer
21 for the first time period of relatively short duration will operate
actuator 17 but will not operate actuator 13 which has a response
time longer than such relatively short first time period. On the
other hand, operation or closing of single switch 20 by programmer
21 for the second time period of relatively long duration will cause
actuator 13 to regenerate the water softener.
Accordingly, it will be apparent that by initiating in a manner
known per se the operating times and time periods of programmer
21 it is possible to determine the selective operations of distributor
14 and regeneration valve 12.
Programmer 21 controls in a traditional manner not described herein
all of the operating elements of the dishwashing machine. Considering
only the operating phases of the dishwashing machine pertinent to
the present invention, after a suitable quantity of water has been
supplied to wash tub 1 reservoir 9 contains a metered quantity
of regeneration water from conduit 5. At this point, the programmer
starts a washing phase of the machine, during which recirculation
pump 3 is operated and switch 20 is closed for the first time period
of relatively short duration, for example several seconds less than
the response time of actuator 13. Accordingly, only actuator 17
is operated which causes compartment 15 of distributor 14 to open,
thereby resulting in distribution of a previously charged detergent
dose into tub 1. During a final phase of the operating cycle of
the dishwashing machine, programmer 21 again causes switch 20 to
open for a brief time period, shorter than the response time of
actuator 13 resulting in the delivery of a dosage of another additive,
for example brightener, from distributor 16 into the wash tub.
Thereafter, programmer 21 then causes switch 20 to close for the
second time period of relatively long duration, for example several
minutes, and longer than the response time of actuator 13. Thereby,
valve 12 is opened and regeneration of water softener 8 is achieved
in a previously known manner. On the other hand, the closing of
switch 20 for the time period of long duration and the resultant
excitation of actuator 17 will produce no effect on distributor
14 since such distributor previously was emptied. In a known manner,
the opening of valve 12 causes water from reservoir to flow by gravity
through conduit 11 salt container 10 and valve 12 thus regenerating
water softener 8.
It is to be understood that the periods of closing of single switch
20 can be determined by programmer 21 to be at times other than
those discussed above, and the particular sequence does not form
a portion of the present invention. For example, the start of the
regeneration phase may occur at the beginning of the cycle of operation
of the washing machine, concurrently with the delivery of detergent
from compartment 15 of distributor 14. Alternatively, the regeneration
operation could be started simultaneously with the delivery of brightener
from distributor 16. In any case, it is sufficient that programmer
21 closes single switch 20 for a time interval longer than the response
time of actuator 13 to thereby open valve 12 to regenerate the water
softener. In must be kept in mind that the volume of water collected
in reservoir 9 should be lower than or equal to the volume of water
softener 8 so that (as is known) during the regeneration operation
(at whatever time during the cycle of operation of the dishwashing
machine), excess brine is not caused to enter wash tub 1.
Although the present invention has been described and illustrated
with respect to preferred features thereof, it is to be understood
that various modifications and changes may be made to the specifically
described and illustrated features without departing from the scope
of the present invention. For example, it is contemplated that distributors
15 16 may be separate elements, each provided with an associated
actuator 17 connected in parallel to other actuators and having
response times shorter than the response time of actuator 13. |