[0001] The present invention concerns a dishwashing machine provided with a device for the
division of the water flow between the upper and lower sprinkler, consisting in a
nozzle of variable flow rate preferably achieved by the relative motion of two members
of said nozzle so as to change the water flow cross-section.
[0002] In presently available dishwashing machines it is only possible an intervention to
decrease the washing cycle duration for reduced loads, or the overall flow of the
machine, yet without the possibility of changing the division of the flow between
the upper and lower sprinkler.
[0003] The object of the present invention is to provide a dishwashing machine capable of
carrying out the above-mentioned division of the flow by means of a variable section
nozzle, wherein the adjustment of the flow is preferably carried out by means of the
relative motion of two members of said nozzle so as to change the water flow cross-section.
[0004] Since the overall flow supplied by the dishwashing machine pump remains constant,
the change of the flow rate of one nozzle involves an opposite change in the flow
rate of the other nozzle, whereby it is possible to differentiate the flow and pressure
of the water reaching the upper sprinkler and the lower one by acting on one nozzle
only.
[0005] Therefore, the dishwashing machine according to the present invention has the advantage
that it is possible to direct a water stream of greater intensity towards the most
soiled dishes, or a stream of lower intensity towards the less soiled ones or those
requiring a less vigorous washing because they are more fragile and/or more delicate.
[0006] This and other advantages and features of the dishwashing machine according to the
present invention will be apparent from the following detailed description of a preferred
embodiment thereof, reported as non-limiting example, referring to the annexed drawings,
wherein:
Fig. 1 is a partially sectional schematic front view of the present dishwashing machine,
wherein the front door has been removed to expose the inner elements;
Fig.2 is a longitudinal cross-sectional view of an embodiment of an adjustable nozzle incorporated
in said machine, illustrated in the maximum flow position; and
Fig.3 is a view similar to the preceding one with the nozzle in the minimum flow position.
[0007] Referring to fig.1, there is seen the positioning of the variable flow nozzle 1 on
the roof of the washing space to feed the upper sprinkler 3; this position facilitates
its adjustment by the user, but the same nozzle 1 could be alternatively positioned
on the base of the space to feed the lower sprinkler 4.
[0008] As already mentioned above, the constant capacity pump 5 supplies the water feeding
the upper sprinkler 3 and the lower one 4; the change in the cross-section of nozzle
1 causes a change in the feed flow to sprinkler 3 proportional to said cross-section
change, and consequently an opposite change in the flow to sprinkler 4, not considering
the flow resistance in the upper supply duct 6.
[0009] In this way, the use of the dishwashing machine is more flexible since, for example,
it is possible to put the dishes soiled some hours before in the upper rack and those
just soiled in the lower rack, and then increase the cross-section of nozzle 1 to
make a stronger washing of the dishes on which dirt had time to stick more firmly,
and this without any need to extend the washing cycle with greater water, power and
detergent consumption.
[0010] Similarly, to wash particularly delicate dishes such as, for example, light crystal
goblets or plates with non-resistant decorations, it is possible to reduce the cross-section
of nozzle 1 to decrease the intensity of the stream hitting said dishes.
[0011] Referring now to figs.2 and 3, there is illustrated an embodiment of the variable
section nozzle, wherein a fixed nozzle 7, mounted at the outlet of the upper supply
duct 6 in fig.1, is integral with a central body 8 connected thereto through one or
more radial fins extending between said body 8 and nozzle 7; an adjustment nut 9 is
mounted on said nozzle 7 so as to shift axially with respect thereto, for example
by means of a threading, and is internally shaped so that the area of the flow cross-section
included between said nut 9 and body 8 changes between a maximum value with the nut
completely forward (fig.2) and a minimum value with the nut completely back (fig.3).
[0012] It should be noted that this minimum value could be nothing, as a limit, so as to
direct the whole flow from the pump to the other sprinkler. Moreover, the coupling
between nozzle 7 and nut 9 also includes a end stop for the limitation of the maximum
flow rate, which depends, however, on the pump supply capacity.
[0013] It should also be noted that the connecting fins between body 8 and nozzle 7 are
useful also for straightening the water flow so that it is less turbulent and therefore
the least possible dispersion is achieved in the passage between nozzle 1 and collector
2 of the upper sprinkler 3 (fig.1).
[0014] Finally, it should be noted that the above described device for changing the nozzle
cross-section may be replaced by a similar device, for example a bored transverse
central body which is rotated to change the passage port, without the operation of
the present machine being altered.
1. A dishwashing machine characterized in that it includes an adjustable nozzle (1) changing
the division of the water flow between the upper sprinkler (3) and the lower sprinkler
(4).
2. A dishwashing machine according to claim 1, characterized in that said adjustable
nozzle (1) comprises an adjustment nut (9) for the relative motion of two members
of said nozzle (1).
3. A dishwashing machine according to claim 2, characterized in that said adjustment
nut (9) of nozzle (1) shifts with respect to a fixed nozzle (7) by means of a threading,
said fixed nozzle (7) containing therein a central body (8).
4. A dishwashing machine according to claim 1, characterized in that said nozzle (1)
is positioned on the roof of the washing space of said machine.
5. A dishwashing machine according to claim 4, characterized in that nozzle (1) includes
members suitable to reduce the turbulence of the water flow being directed to a collector
(2) of the upper sprinkler (3).