[0001] The present invention refers to a device for intercepting the flow of a fluid that
passes through a distributing circuit, in particular for washing machines.
[0002] As known, in the field of washing machines, the use of flow diverting or intercepting
devices applied to dishwashers has a particular importance.
[0003] Usually, dishwashers for household usage comprise a box-shaped structure defining
a washing chamber that houses an upper loading basket and a lower loading basket,
being intended for containing the items to be washed. A sprayer is positioned under
each loading basket which, by rotating around a substantially vertical axis, hits
the dishes placed in the basket with a plurality of washing liquid jets; to this purpose,
a special motor-driven recirculation pump conveys the liquid under pressure to the
sprayers.
[0004] In some known applications, especially aimed at reducing water consumption, the hydraulic
circuit of the dishwasher is obtained in such a way to execute a washing cycle by
feeding a single sprayer, or by feeding both sprayers alternately.
[0005] The first solution is typical of cases in which the dishwasher must be able to carry
out a so-called "reduced" washing program, i.e. when only one of the basket is used
to contain the dishes, and only the sprayer that corresponds to the used basket must
be fed with the washing liquid.
[0006] The second solution mentioned above, concerning the alternate feeding of the sprayers,
is spreading currently in dishwashers and its aim is substantially to:
- allow for the use a single recirculation pump, for both sprayers, whose electric motor
has relatively small dimensions; it is clew that, on this score, should the same pump
feed at the same time two sprayers, it must have a more powerful and hence bigger
motor;
- reduce the operating noise of the machine, being determined by the impact against
the walls of the washing chamber of the liquid jets streaming through the sprayers;
- allow for a certain saving in water consumption.
[0007] In general, in the first case mentioned previously, a device can be provided for
a continuous interception of the liquid flow coming from the recirculation pump to
one of the two feeding branches of the sprayers; the intercepting device, being duly
controlled by the machine control system, keeps one of the two branches of the hydraulic
circuit closed, in such a way as to feed with the liquid, throughout the washing program,
only the sprayer related to the used basket.
[0008] In the second case mentioned above, an intercepting device is instead provided for
directing alternately the liquid in one of the two branches mentioned above; in other
words, the control system of the machine controls the intercepting device in such
a way that the latter opens and closes alternately the two branches of the hydraulic
circuit, in such a way that the washing cycle is obtained by feeding alternately the
upper and lower sprayer.
[0009] It should be noticed that, in some solutions, a same intercepting device can execute
both of the above-mentioned functions, i.e. continuous closing on one of the two circuit
branches, in order to carry out a "reduced" washing program, and flow deviation in
the two branches, in order to carry out a washing with alternate feeding of the sprayers.
[0010] In general, an intercepting device used to obtain an alternate washing comprises
substantially a movable flap or plug, placed in correspondence of the point where
the two above-mentioned branches of the hydraulic circuit depart; said plug can assume
at least a first operating condition, characterised by the opening of the branch that
feeds the upper sprayer and by the closing of the branch that feeds the lower sprayer,
and a second operating condition, opposed to the previous one.
[0011] In some cases, the movement of the above-mentioned plug from one position to the
other is obtained by means of a electric-thermal actuator.
[0012] The actuators of the thermal type are well known and do not need an in-depth description
here (see for example EP-A-940 577). It is enough to specify here that these actuators
comprise usually a body containing a thermoexpansible material and, at least partially,
a piston; a heater is associated to the mentioned body, like a resistor with a positive
temperature coefficient, or PTC.
[0013] The heating of the actuator's body, induced by the resistor, determines a volume
expansion of the expandable material, and the resulting exit movement of the piston,
whose thrust is used to move the plug of the flow diverting device from the first
to the second operating condition.
[0014] Later, when the electric supply to the resistor is interrupted, the temperature of
the actuator's body decreases, with the ensuing volume contraction of the thermoexpansible
material; the piston can therefore retract towards the inside of the body, upon the
action of an elastic element, like a spring, and in this way switch back the plug
of the flow intercepting device from the second to the first operating condition.
[0015] Therefore, as it can be imagined, through a series of repeated activations and deactivations
of the actuator's heater, it is possible to feed the washing liquid alternately to
the two sprayers.
[0016] Although the technique described above is reliable on the average, it presents some
drawbacks.
[0017] The first drawback derives from the fact that the control system of the dishwasher,
whether electromechanical or electronic, presumes a certain complexity to obtain the
required feeding cycles of the thermoactuator.
[0018] Another drawback of the mentioned solution derives from the fact that the operating
times of a thermal actuator are relatively long, since the movements obtained from
it are linked to the heating and cooling phenomena of a thermoexpansible material.
A drawback connected to the previous one consists of the fact that the operating times
of a thermal actuator are different in the two operating stages; in other words, the
time required to produce the heating of the thermoexpansible material and the ensuing
exit movement of the piston from the actuator's body is different from the time required
to obtain the cooling of the same material, and the ensuing backing of the piston.
[0019] It follows that the opening times of the two different branches of the dishwasher's
hydraulic circuit can be different.
[0020] In other known solutions, in order to obtain the desired movement of the plug or
shutter of the intercepting device, a double winding motor is provided, instead of
a thermal actuator.
[0021] In this case, the motor is initially operated with a first direction of rotation,
by energising its first winding, to move the shutter from its first to its second
working position; then, the direction of rotation of the motor is inverted, energising
its second winding, in order to return the shutter to its initial position.
[0022] In the simplest solutions, the supply of the mentioned double winding is time-controlled,
i.e. it is supplied for a fixed period being considered sufficient to determine the
passage of the shutter from one working position to the other.
[0023] However, as time goes by, the calibration or adjustment of the diverting device can
be compromised; for example, this is due to the fact that some plastic parts of the
intercepting device are exposed to continuous thermal stresses, and hence potentially
subject to variations in size. In these circumstances, the time set for the motor
supply may result longer or shorter of the one strictly required to obtain a correct
positioning of the shutter, with ensuing operating extrastrokes or efforts, which
can break the intercepting device or cause the failure of its motor, or make it impossible
to reach the correct working position of the shutter.
[0024] In most sophisticated solutions, special sensors like microswitches are provided,
apt to detect that the shutter has reached the proper working position; at this point,
the control system of the machine controls the inversion of the direction of rotation
of the motor, until the attainment of the new working position is detected, and so
on throughout the "reduced" washing cycle.
[0025] Although the solution mentioned above is reliable on the average, it assumes however
the use of a relatively expensive motor, as it is expensive and complex the system
for controlling the supply and the direction of rotation of such a motor.
[0026] The present invention has the aim of solving the above drawbacks of the prior art.
[0027] Within this frame, the aim of the invention is to indicate a device for intercepting
the flow of a fluid, in particular for washing machines, being of simple design and
manufacturing, being highly reliable in time and being of low cost.
[0028] These and other aims are achieved, according to the present invention, by a device
for intercepting the flow of a fluid, in particular for a washing machine, having
the characteristics of the annexed claims, which form an integral part of the present
description.
[0029] Further aims, features and advantages of the present invention will become apparent
from the following detailed description and the annexed drawings, which are supplied
by way of non limiting example, wherein:
- Fig. 1 shows a schematic section of a dishwasher that uses a liquid flow intercepting
device according to the present invention;
- Fig. 2 represents a plan view of the intercepting device of the dishwasher of Fig.
1;
- Fig. 3 represents a side view of the intercepting device of Fig. 2;
- Fig. 4 represents a first exploded view of.some components of the intercepting device
of Fig. 2 and 3;
- Figs. 5 and 6 represent a second and third exploded view of some components of the
intercepting device of Fig. 2 and 3, according to two different angles;
- Figs. 7 and 8 represent sections of the intercepting device according to the invention,
by axis B-B and axis C-C respectively of Fig. 3, in a first working position;
- Figs. 9 and 10 represent sections of the intercepting device according to the invention,
by axis B-B and axis C-C respectively of Fig. 3, in a second working position.
[0030] Fig. 1 shows a schematic representation of a dishwasher using an intercepting device
obtained according to the principles of the present invention.
[0031] In this figure, 1 indicates the washing chamber of the machine, comprising a lower
collecting sump, indicated with 2; 3 indicates a washing or recirculation pump, equipped
with an electric motor.
[0032] 3A indicates the suction branch of the mentioned pump, that draws the washing liquid
from the sump 2; pump 3, by means of its delivery 3B, forces the washing liquid in
a hydraulic circuit, comprising a first branch 4 feeding a lower sprayer 5, and a
second branch 6 feeding an upper sprayer 7; baskets 8 and 9 are placed in a known
way above of each sprayer.
[0033] 10 indicates a device for intercepting a flow of liquid, placed between the inlets
of the two branches 4 and 6, which is properly controlled by the machine's control
system, as it will be clear later.
[0034] The intercepting device 10 is capable of assuming at least two different alternative
operating conditions, and in particular:
- a closing condition of branch 4, represented in Fig. 1, with opening of branch 6 at
the same time;
- a closing condition of branch 6, with opening of branch 4 at the same time.
[0035] The intercepting device 10, which is shown in different views in Figs. 2 and 3, comprises
a main body 11, for example realised in thermoplastic material, defining an inlet
12 for the connection to the delivery 3B of pump 3, and two outlets 13A and 13B for
the connection to the feeding branches 4 and 6 respectively, of the lower sprayer
5 and the upper sprayer 7; the body 11 comprises an upper part 11A and a lower part
11B, coupled with known means, with a gasket placed in between, not represented in
the figures.
[0036] Inside the body 11, a plug or shutter member 14 is placed between inlet 12 and outlets
13A and 13B; in the example, this plug is of the rotating or angular movable type.
[0037] An electric motor 15 is associated to the upper part of body 11, by means of screws
16 intended for being screwed in suitable seats 17 defined in the body 11.
[0038] Motor 15, which, if necessary, is equipped with a suitable internal gear-reducer,
presents a shaft 15A that is connected to a suitable transmission element ET, made
integral with plug 14 or realised as a single piece with the latter; obviously, on
the upper part of body 11 a proper opening is defined, for the passage of a part of
the transmission element ET, in correspondence of which proper sealing means are preferably
provided.
[0039] AP indicates an additional member, coupled with the transmission element ET, presenting
a radial projection AP'; 18A and 18B indicate two stops with which projection AP'
is able to come into contact following an angular movement of the transmission element
ET (see, to this purpose, also Figs. 7 and 9). It should be noticed that, in the given
example, the above-mentioned stops 18A and 18B consist of projections of the upper
part 11A of body 11, which are used also as supporting and positioning means for the
motor 15.
[0040] In Figs. 4-6 some components of the intercepting device 10 according to the invention
are represented in more detail.
[0041] In these figures notice the particular shape of plug 14, which is defined as a whole
by an upper circular wall 14A and a lower circular wall 14B, joined together by means
of a bent wall 14C extending for nearly half of the circumference of the said walls
14A and 14B; in other words, therefore, the plug 14 has substantially the shape of
a hollow cylinder whose circumference wall lacks a portion. However, it is clear that,
in the practical actuation of the invention, the shape of the plug 14 may differ from
the one in the example of the figure, like for example a substantially spherical shape,
where a passage or a discharge having a proper shape is defined in order to allow
the required hydraulic connection between the inlet 12 and the outlet 13A, and between
the inlet 12 and the outlet 13B.
[0042] It should be noticed that, in the given example, discharges or undercuts having substantially
a semicircular shape are defined at the two side ends of the bent wall 14C, indicated
with 14D, with dimensions being congruent to that of the outlets 13A and 13B of the
device 10.
[0043] The transmission element ET is coupled to the upper wall 14A of the plug 14, or realised
as single piece with the latter; in the lower part of the transmission element ET,
i.e. the one that remains within body 11 of the intercepting device 10, are defined
one or more seats ET', for the housing of an equal number of proper sealing means,
like one or more o-rings, not represented.
[0044] The upper part of the driving element ET, i.e. the one remaining outside the body
11 of the intercepting device 10, is indicated in Figs. 4-6 with ET"; at the upper
end of part ET", on its external surface, a discharge or undercut 19 is defined, whose
function will be explained later; part ET" is internally hollow, for defining a seat
20 able to receive the end of shaft 15A of motor 15.
[0045] The end portion of shaft 15A and seat 20 present congruent sections, so that the
angular movement of the shaft determines a corresponding movement of the transmission
element ET; for this purpose, in the example of the figure, the end of shaft 15A and
seat 20 present a substantially semicircular section, or an or equivalent one; on
the other hand, it is clear that such a section can have any other shape proper for
the object, like for example a square or hexagonal shape.
[0046] The additional member AP presents a housing (not visible in the figures) in its lower
part, being able to receive and couple with the upper end of part ET" of the or transmission
element ET, where the mentioned discharge or undercut 19 is defined.
[0047] Also in this case, therefore, the upper end of part ET" and the mentioned housing
of the member AP are designed in such a way that the angular movement of the transmission
element ET determines a corresponding movement of the member AP and of the relative
radial projection AP'.
[0048] Anyway, in order to ensure further that to the angular movement of the driving element
ET, and so of plug 14, corresponds an equivalent movement of the projection AP', the
central passage of member AP, indicated with 21, can advantageously present a section
congruent to that of seat 20 and to the end portion of shaft 15A (as said, in. the
example of Fig. 4, this section has a substantially semicircular shape).
[0049] However, notice that the coupling between shaft 15A, member AP and element ET can
be obtained with any known technique.
[0050] In the preferred embodiment of the present invention, motor 15 is a single-phase
synchronous motor, having a single winding and a permanent magnet rotor.
[0051] As known, this kind of motor has no preferred starting direction, i.e. its rotor
is able to start and rotate in both directions (clockwise and counter-clockwise) indifferently.
It also known that, if during the angular movement in one direction, the rotor is
subject to a braking moment or is exposed to a thrust in the opposite direction, the
mentioned type of motor reaches a stall condition, which is automatically followed
by a reversal of the direction of angular movement of the rotor, due to electromagnetic
effect. It is also known that the rotor or the shaft of the mentioned type of motors
has a substantially fixed revolution speed, which depends on the mains frequency,
on the motor's specifications (for example the number of poles) and on the possible
presence of a gear reducer.
[0052] Therefore, according to the invention, in order to invert the direction of rotation
of motor 15, and of shaft 15A, the stops 18A and 18B are provided, with which projection
AP' comes into contact alternately, according to the direction of clockwise or counter-clockwise
rotation of the motor; as it can be imagined, in this way, plug 14 can be moved by
the transmission element 14A in opposite directions, in order to open and close alternately,
and with equal times, the outlets 13A and 13B of the intercepting device 11.
[0053] Finally, it should be noticed that, preferably, the end of projection AP' intended
to come into contact with the stops 18A and 18B is equipped with elastic elements,
such as a rubber covering, in order to create a bouncing effect, i.e. for contributing
to give projection AP', as well as element ET and shaft 15A, an angular movement having
a direction being opposite to that of impact on one of the stops.
[0054] Obviously, for this reason, the elastic elements can be provided on stops 18A and
18B, instead of on projection AP', or the same projection AP' can be shaped for giving
the latter a certain elasticity that is useful for the purpose.
[0055] The dishwasher equipped with the intercepting device according to the present invention
works as follows.
[0056] After loading the dishes in the baskets 8 and 9, the user selects the desired washing
cycle and starts the machine; the washing cycle described later provides for this
reason the alternate supply of the sprayers.
[0057] Therefore, the control system of the machine controls the execution of the washing
cycle, including its usual phases, like for example one or more prewash phases, one
or more washing phases, one or more rinsing phases, according to the technique of
supply alternation the sprayers.
[0058] In general, each phase of the cycle starts by loading in tank 1 the required water
quantity, measured with known modalities (for example by means of a pressure switch).
Therefore, once the quantity of water required by the first prewash phase has been
loaded from the external water mains, the control system controls the activation of
the recirculation pump 3 by supplying the motor of the latter.
[0059] In parallel with the activation of pump 3, the control system of the machine enables
the supply of motor 15 of the intercepting device 10. Motor 15 therefore starts turning
in one direction, and so moves plug 14, for example towards the closing position of
outlet 13A and simultaneous opening of outlet 13B of the intercepting device 10; this
situation is shown in Fig. 8.
[0060] When plug 14 reaches this position, projection AP' reaches stop 18A, as shown in
Fig. 7; the mechanical effect deriving from the contact between projection AP' and
stop 18A is that the transmission element ET, as well as shaft 15A of motor 15, are
subject to a braking and/or bouncing action as defined above; motor 15 reaches a stall
condition and changes its direction of rotation.
[0061] This means that motor 15 starts turning in a second direction, being opposite to
the previous one, and so moves plug 14 towards the closing position of outlet 13B
and simultaneous opening of outlet 13A of the intercepting device 10; this situation
is shown in Fig. 9.
[0062] In this case, when plug 14 reaches this position, projection AP' reaches stop 18B
(as shown in Fig. 8); also in this case, the mechanical (i.e. braking and/or bouncing)
effect that the contact between projection AP' and stop 18B determines on the driving
element ET and on shaft 15A causes motor 15 to reach a stall condition, and the new
subsequent reversal of its direction of rotation.
[0063] This operation of motor 15 and of the intercepting device 10 continues throughout
the relative phase of the washing cycle, and preferably throughout the activation
of pump 3; said phase then ends by discharging the washing water from tank 1 by means
of a suitable pump, not represented in Fig. 1.
[0064] The above is followed a new supply of water in the tank, in order to carry out the
following phase, which is executed in the same way as the one described previously,
and so on for all the other phases of the washing cycle.
[0065] As said, motor 15 has no preferred starting direction, but as it can be imagined,
this is practically irrelevant in view of the proper and efficient operation of the
dishwasher; the position of plug 14 before starting motor 15 is practically irrelevant,
too.
[0066] The alternate feeding of the sprayers is obtained as described above.
[0067] During manufacturing, the motor 15 will be realised with known modalities in order
to obtain a proper speed of shaft 15A, which determines the desired switching speed
of plug 14 from one working position to the other; these speed values depend on the
mains frequency as well as on the motor specifications (for example, on the number
of its poles) and/or on the possible presence of a gear reducer; for what concerns
this aspect, it should be pointed out that the prevision of a proper gear reducer
realised as known, seems to be preferable, in order to have a small motor 15, whose
shaft 15A is anyway able to produce high forces or torques, being adequate to the
purpose.
[0068] Advantageously, motor 15 can be connected electrically in parallel with respect to
the motor of pump 3, in such a way as to ensure a simultaneous supply, and therefore
a simultaneous operation of device 10 and of the said pump 3.
[0069] From the above description the features of the present invention are clear.
[0070] In particular, an intercepting device has been described, for a flow of a fluid that
passes through a distributing circuit (branches 4 and 6), in particular of a washing
machine; the device (10) comprises an actuator (motor 15) presenting a displacement
part (shaft 15A) that can work in two opposite directions, said displacement part
being able to displace a plug (14) which can move until it reaches at least a respective
first working position.
[0071] The intercepting device (10) comprises striker means (member AP and corresponding
radial projection AP') that follow the movement of plug (14) and are capable of come
into contact with respective fixed stopping surfaces (stops 18A and 18B), where the
contact of the strikers with a first of the stopping surfaces corresponds to the attainment,
by plug (14), of the said first working position.
[0072] According to the invention, under constancy of electric supply to the actuator (15),
the latter is capable of inverting the direction of movement of the displacement part
(15A) automatically, following the effect (in particular a mechanical one) that the
contact of the striker means (AP,AP') with one of the stopping surfaces (18A,18B)
determines on the displacement part (15A).
[0073] The plug (14) is capable of reaching at least a second working position, where the
contact of the striker means (AP,AP') with a second one of the stopping surfaces corresponds
to the attainment, by plug (14), of said second working position. In this way, following
the automatic reversal of the direction of movement of the displacement part (15A)
determined by the contact of the striker means (AP,AP') with the stopping surfaces
(18A,18B), the plug (14) is continuously moved in opposite directions, in order to
pass in an alternate way between the said first and the said second working position.
[0074] In the preferred embodiment by the invention, the actuator comprises at least one
single-phase synchronous motor, in particular having a single winding and a permanent
magnet rotor, and the speed of the displacement part is determined by the mains frequency
and/or by a gear reducer.
[0075] The invention has a specially advantageous application in the field of dishwashers,
for the realisation of washing cycles with alternate supply of the sprayers; however,
it is clear that the described device can be applied also on other kinds of washing
machines for household usage, like for example laundry washers and/or washer-dryers,
and on other devices and systems where it is useful or necessary to realise a cyclical
deviation or interruption of the flow of a fluid, whether liquid or aeriform.
[0076] Moreover, it should be pointed out that the device according to the invention must
not be perceived as applicable exclusively to cases in which a first duct must be
completely closed in favour of another one, but can be provided instead for partializing
or adjust the flow-rate of the fluid which has to be cyclically fed to the two ducts.
[0077] Within this frame, the shape of plug 14 and the two end-of-stoke positions of the
latter can be chosen in order to obtain only a suitable narrowing or throttling of
the distributing circuit, between the inlet 12 and the outlet 13A on one side, and
between the inlet 12 and the outlet 13B on the other side.
[0078] This variant can be applied when the two branches of the distributing circuit of
the fluid that depart from the outlets of the device according to the invention must
be fed substantially in an alternate way with different liquid flow rates, for example
in order to obtain a wash with different washing pressures for sprayers 5 and 7, if
the dishes contained in basket 9 are more fragile than those in basket 5.
[0079] Within this frame, the terms "intercepting device" and "plug member" used here must
be intended in their more general meaning, i.e. indicating respectively a device that
allows also the partial closure of a duct, and a member that allows to adjust the
flow rate of a fluid.
[0080] For what concerns the application mentioned just now, it should also be pointed out
the possibility of changing the realisation of the stops 18A and 18B, in order to
allow for the adjustment of their position with respect to the shaft 15A or the projection
AP'; for example, in the simplest embodiment, each stop can consist of the end of
a threaded element, being screwed in a respective seat that extends substantially
perpendicularly to the shaft 15, said seat being defined in a proper support that
raises from the upper surface of body 11.
[0081] In this way, therefore, by screwing more or less the above-mentioned threaded elements
in their seat, it is possible to adjust or vary the position of the stop points of
projection AP', i.e. of its end-of-stroke points in the two opposite directions of
movement, with the ensuing possibility of changing the two working positions of plug
14 and adjusting the flow-rate of fluid to be fed at outlet 13A and 13B of the device
10.
[0082] From the above description the advantages of the present invention are also clear.
[0083] After carrying out exhaustive practical tests, the device for intercepting the flow
of a fluid according to the present invention resulted in resolving efficiently the
previously mentioned typical problems of the prior art. In particular,
- the control system of the intercepting device 10, and therefore of the apparatus comprising
it, is not complicated; the control of motor 15 is obtained simply, through a constant
electric supply of the same, which in the case of dishwashers is obtained preferably
together with the activation of the recirculation pump 3;
- the operating times of the intercepting device 10 are practically fixed and the duration
of the alternate opening/closing phases of branches 4 and 6 of the hydraulic circuit
of the machine is always the same;
- the motor 15 of the intercepting device 10 is simple and cheap, since it does not
need a double winding for allowing the controlled reversal of its direction of rotation,
and is of a common and reliable type;
- thanks to the intrinsic characteristics of the motor 15, possible accidental changes
in the calibration or adjustment of the intercepting device 10 are irrelevant for
the purpose of the proper operation of the latter, without extra-stroke risks or operating
efforts being typical of the prior art;
- in order to control the supply and the direction of rotation of motor 15, the intercepting
device 10 does not require sensors for the detection of both working positions of
the plug 14.
[0084] It is obvious that many. changes are possible for the man skilled in the art to the
intercepting device described as an example, without departing from the novelty spirit
of the inventive idea.
[0085] For example, the possibility is mentioned of providing a single sensor for the intercepting
device 10, in order to detect the attainment of one of the two working position of
the plug 14; this variant, which remains in any case advantageous with respect to
the prior art mentioned previously, can prove to be useful when it is desired to assign
to the switching device 10 also the function of continuous closing of one of the two
branches 4 and 6 of the supply circuit of sprayers 5 and 7, in order to obtain a "reduced"
washing programme, i.e. obtained by using only one of the basket 8 and 9.
[0086] For example, a magnetic element can be associated to projection AP' and a proper
known position switch or sensor (for example a reed sensor or a Hall effect sensor)
can be associated to the intercepting device 10; in this case, the position switch
or sensor shall be properly connected to the control system of the machine, and calibrated
for detecting the attainment, by the projection AP', of the contact position on one
of the two stops, like for example the stop 18A.
[0087] The operation of the dishwasher according to the proposed variant is the following.
[0088] The user loads the dishes in the basket set for the execution of the reduced washing
cycle (indicated on the machine's handbook), which in the example is the upper basket
9.
[0089] After selecting and starting the said cycle, the first phase (prewash) starts with
the corresponding loading in tank 1 of the required water quantity.
[0090] During said loading, the control system of the machine checks, by means of the mentioned
position switch or sensor, if the projection AP' and plug 14 are in the correct closing
position of the outlet 13A and opening of the outlet 13B of the intercepting device
10.
[0091] In the negative, the control system of the machine enables the power supply of motor
15, until the switch or sensor detects that the above-mentioned correct position has
been reached (notice that, in compliance with this variant, the device 10 can be provided
with an electric supply being independent from that of pump 3, so that the motor of
the first one and of the second one can be driven by the machine control system also
at different moments).
[0092] At this point, the supply to motor 15 is interrupted, and plug 14 is in closing position
of outlet 13A and opening of outlet 13B of the intercepting device 10. This phase
of correct positioning of plug 14 is obviously obtained in quite a short time, and
during the water loading step in tank 1. In the case in which, on the contrary, the
position sensor informs initially the control system that plug 14 is already in the
correct position, the motor 15 is not supplied.
[0093] Therefore, once the quantity of water required by the first prewash phase has been
loaded from the external water mains, the control system controls the activation of
the recirculation pump 3, by supplying the motor of the latter.
[0094] Due to the closing of branch 4 of the hydraulic circuit, all the washing water shall
be pushed by pump 3 in branch 6, and then to the upper sprayer 7, in order to wash
the dishes contained in basket 9; the cycle phase proceeds in this way until the washing
water is drained from tank 1 by means of the proper pump.
[0095] The above-mentioned operating condition of intercepting device 15 is maintained throughout
the following phases of the washing cycle, i.e. without the need to carry out further
positioning controls of plug 14.
[0096] As seen, therefore, in the above way the intercepting device 10 can also be used
to execute a reduced washing cycle, with a given basket of the machine (i.e., in the
example, the upper basket 9).
[0097] On the other hand, it is clear that a washing machine using the fluid intercepting
device according to the present invention can be easily prearranged in order to offer
the user the possibility to select the basket to be used in order to execute the reduced
washing cycle.
[0098] For this case, the control system of the machine can be equipped with a special selector
means, placed on the control panel of the machine, provided for the choice of the
basket to be used; on the other hand, the intercepting device 10 shall be equipped
with two position sensors able to detect the required positioning of plug 14 according
to what the user has selected, i.e.
- the closing position of outlet 13A of the intercepting device 10, when the user has
chosen to carry out the reduced washing using the upper basket 9,
or
- the closing position of outlet 13B of the intercepting device 10, when the user has
chosen to carry out the reduced washing using the lower basket 10.
[0099] It is obvious that the type and operation of the two mentioned position sensors shall
be similar to the one described previously, and therefore one for detecting that projection
AP' has reached the contact position on stop 18A, and the other on stop 18B.
[0100] Finally, it is obvious that the sensor/s provided may be provided for detecting directly
the position of plug 14, and not indirectly by means of the projection AP'; in this
case, the magnetic element mentioned previously shall be associated directly to the
plug 14.
[0101] Appendix AP' can be integral with the shaft 15A of motor 15, rather than with the
transmission element ET; likewise, the same projection AP' can be replaced by at least
a projection or a part of the plug 14, and the stops 18A and 18B can be replaced by
proper end-of-stroke means being defined within the body 11.
[0102] It is anyway obvious that many changes are possible for the man skilled in the art
to the intercepting device described as an example, without departing from the novelty
spirit of the inventive idea, and it is also clear that in the practical actuation
of the invention the different components, elements and materials described previously
may be replaced with technical equivalent elements.
1. Device for intercepting the flow of a fluid that passes through a distributing circuit
(4,6), in particular of a washing machine, where the said device (10) comprises
- an actuator (15) presenting a displacement organ (15A) capable of working in two
opposite directions, said displacement organ (15A) being able to move a movable shutter
member (14) until the latter reaches at least a first working position,
- striker means (AP,AP') that follow the movement of said shutter member (14) and
are capable of coming into contact with respective fixed stopping surfaces (18A,18B),
the contact of said striker means (AP,AP') with a first one of said stopping surfaces
(18A,18B) corresponding to the attainment by said shutter member (14) of said first
working position,
characterised in that, under constancy of electric supply to said actuator (15),
the latter is capable of automatically reversing the direction of movement of said
displacement organ (15A), as a result of the effect, in particular the mechanical
effect, that the contact of said striker means (AP,AP') with one of said stopping
surfaces (18A,18B) determines on said displacement organ (15A).
2. Device, according to claim 1, characterised in that said shutter member (14) is capable
of reaching at least a second working position, where the contact of said striker
means (AP,AP') with a second of said stopping surfaces (18A,18B) corresponds to the
attainment by said shutter member (14) of said second working position.
3. Device, according to claim 2, characterised in that
- in said first working position, said shutter member (14) provides for closing at
least partially a first branch (4) of said circuit and allowing the passage of the
flow of the fluid in a second branch (6) of said circuit, and
- in said second working position, said shutter member (14) provides for closing at
least partially said second branch (6) and allows the passage of the flow of the fluid
in said first branch (4).
4. Device, according to claim 2 o 3, characterised in that following the automatic reversal
of the direction of movement of said displacement organ (15A) determined by said contact
of said striker means (AP,AP') with said stopping surfaces (18A,18B), said shutter
member (14) is continuously moved in opposite directions for passing in an alternated
way between said first and said second working position.
5. Device, according to claim 1, characterised in that said actuator comprises an electric
motor (15) of the single-phase synchronous type, in particular having a single winding
and a permanent magnet rotor.
6. Device, according to claim 5, characterised in that the said rotor is capable of inverting
its direction of angular movement following a braking moment and/or a thrust in the
opposite direction, where in particular connection means (15A) are provided between
said rotor and said striker means (AP,AP') and said braking moment and/or thrust in
the opposite direction is caused by said effect that the contact of said striker means
(AP,AP') with one of said stopping surfaces (18A,18B) determines on said displacement
organ (15A).
7. Device, according to claim 1, characterised in that transmission means (ET) are provided
between said displacement organ or shaft (15A) and said shutter member (14).
8. Device, according to claim 1, characterised in that said intercepting device (10)
comprises a body (11) within which said shutter member (14) is placed, said body (11)
comprising in particular two parts (11A,11B) that are seal coupled.
9. Device, according to claim 8, characterised in that said body (11) defines an inlet
(12) and two outlets (13A;13B) for the fluid flow, said shutter member (14) being
placed within said body (11), between said inlet (12) and said outlets (13A,13B).
10. Device, according to at least one of the previous claims, characterised in that said
shutter member (14) has substantially the shape of a hollow cylinder, whose circumference
wall lacks a portion.
11. Device, according to claim 1, characterised in that elastic means are provided, operating
between said striker means (AP,AP') and said stopping surfaces (18A,18B), and/or said
striker means (AP,AP') has at least partially elasticity features.
12. Device, according to claim 1 or 2, characterised in that sensor means are provided,
for detecting the attainment by said shutter member (14) of at least one of said working
positions.
13. Device, according to the previous claim, characterised in that means are provided
for interrupting the electric supply of said motor (15), when said sensor means detect
the attainment, by said shutter member (14), of a predetermined position among said
working positions.
14. Device, according to claim 12 or 13, characterised in that said sensor means comprise
at least one switch or sensor of the reed type or of the Hall effect type and in that
a magnetic element is associated to said striker means (AP,AP').
15. Device, according to at least one of the previous claims, characterised in that adjustment
means are provided, of at least one of said working positions, said adjustment means
comprising in particular means for varying the position of at least one of said stopping
surfaces (18A,18B).
16. Dishwashing machine for household usage comprising
- at least a hydraulic circuit having at least a collecting sump of the washing liquid
(2), a washing pump (3), at least two liquid sprayers (5,7) and a supply branch (4,6)
for each of said sprayers (5,7), where in order to wash the dishes said pump (3) forces
the liquid from said sump (1) in said supply branches (4,6) of the hydraulic circuit,
- an intercepting device (10) comprising
- an actuator (15) having a displacement organ (15A) capable of working in two opposite
directions, and able to move a movable shutter member (14) until at least a first
working position of the latter is reached, in said first working position said shutter
member (14) being in particular able to exclude from the hydraulic circuit a first
one of said supply branches (4,6),
- striker means (AP,AP') that follow the movement of said shutter member (14) and
are capable of coming into contact with respective fixed stopping surfaces (18A,18B),
the contact of said striker means (AP,AP') with a first one of said stopping surfaces
(18A,18B) corresponding to the attainment by shutter member (14) of said first working
position,
characterised in that, under constancy of electric supply to said actuator (15),
the latter is capable of inverting the direction of movement of said displacement
organ (15A) in an automatic way, as a consequence of the effect, in particular a mechanical
effect, which the contact of said striker means (AP,AP') with one of said stopping
surfaces (18A,18B) determines on said displacement organ (15A).
17. Dishwashing machine, according to the previous claim, characterised in that said shutter
member (14) is capable of reaching at least a second working position, where the second
of said supply branches (4,6) is in particular excluded from the hydraulic circuit,
where the contact of said striker means (AP,AP') with a second one of said stopping
surfaces (18A, 18B) corresponds to the attainment by said shutter member (14) of said
second working position.
18. Dishwashing machine, according to claim 16, characterised in that following the automatic
reversal of the direction of movement of said displacement organ (15A) determined
by the contact of said striker means (14B) with said stopping surfaces (18A,18B),
said shutter member (14) results in being continuously moved in opposite directions
for cyclically passing between said first and said second working position, in particular
in order to supply with liquid both said sprayers (5,7) in an alternated way.
19. Dishwashing machine, according to claim 16, characterised in that sensor means are
provided, capable of detecting the attainment by said shutter member (14) of at least
one of said working positions, and in that the control system of the machine is programmed
to interrupt the power supply of said motor (15), when said sensor means detect that
the shutter member (14) has reached a predetermined position among said working positions,
in particular in order to supply in a continuous way with liquid only one of said
sprayers (5,7).
20. Dishwashing machine, according to claim 16, characterised in that said actuator (15)
is connected electrically in parallel with respect to the motor of said pump (3),
in particular in order to realise a simultaneous operation of said intercepting device
(10) and of said pump (3).