Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
20filO~2
COFFEE OR TEA MACHINE
This invention concerns a coffee or tea machine
with a fresh water container underneath whose outflow a
water-permeable water filter is located on the opposite
facing sides and a water discharge connected to a
continuous-flow heater.
A known method of improving the quality of
brewed beverages is to filter the fresh tap water through
a water filter.
Such a water filter, which is integrated into
the coffee or tea machine, consists basically of a
granulate made of activated charcoal and ion exchangers.
As the fresh water passes through the water
filter, the granulate naturally presents a resistance to
the water flow which results in the amount of water
exiting from the water filter no longer being sufficient
to supply the continuous-flow heater with sufficient
water, especially when the amount of water in the fresh
water container decreases, i.e. the water pressure falls,
so that the water flow through the water discharge breaks
off. This results in a large steam build-up within the
: continuous-flow heater which, for example, produces a
very loud, unpleasant noise. In addition, the remaining
quantity of water flows virtually only drop by drop, so
that it is not possible to heat the brewing water in
portions and to expel it in gushes into a filter
container.
This invention is therefore based on the problem
of designing a coffee or tea machine of the generic type
in such a way that the water flow into the continuous-
flow heater is uniform at every point in the brewing
process.
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This invention solves this problem by providing
a water reservoir to the side and/or under the water
filter which communicates with the latter and discharges
into the water outlet.
If the fresh water container is full, i.e. high
water pressure, a larger quantity of water flows through
the water filter at first than the continuous-flow heater
can heat, so that the water reservoir fills
correspondingly.
As the quantity of water and, correspondingly,
the water pressure, in the fresh water container
decreases, the flow per time unit through the water
filter decreases 60 that finally the quantity of water
heated during every heating operation is greater than the
quantity passing through the water filter. In this case,
the amount of water required for continuous operation of
the continuous-flow heater is taken from the water
reservoir.
It has been shown that the volume of the water
reservoir should be approximately 10 to 20~ of the volume
of the fresh water container but at least the maximum
quantity which can be heated at once by the continuous-
~; flow heater if the machine is to operate~perfectly in the
manner described. In order for the coffee or tea machine
applied for to operate perfectly, it is planned inaccordance with another beneficial inventive idea to
equip the water reservoir with a vent hole, for example
also aombined with a vent pipe whiah runs throu~h the
fresh water container, so that the water reservoir can be
filled or emptied without restriction.
The present invention thus provides a coffee or
tea machine with a fresh water container underneath whose
outflow a water-permeable water filter is located on the
20~1082
opposite facing sides and a water discharge connected to
a continuous-flow heater characteriæed by the fact that a
water reservoir is provided to the side and/or under the
water filter which communicates with the latter and
discharges into the water outlet.
In drawings which illustrate by way of example
only a preferred embodiment of the invention,
Fig. 1 is a schematic representation of a coffee
or tea machine as applied for, partially in cross-
section; and
Fig. 2 is an enlarged view showing details ofexcerpt II in Figure 1.
A coffee or tea machine such as that shown in
Figure 1 has a fresh water container 1 in whose bottom
area, underneath its outflow, there is a water filter 3.
The side of this water filter 3 facing the fresh water
container 1 as well as the opposite side are water-
permeable, a top sieve 6 and a bottom sieve 7 being
provided for this purpose.
The interior of the water filter 3 is filled
with a granulate 11 composed of ion exchangers and
activated charcoal which filters the water flowing
through it. ~ ~
In this embodiment, there is a water reservolr 4
both to the side and underneath the water filter 3 wbiah
communicates with the water filter 3, supporting knobs 8
being provided on its bottom side which support the water
filter 3 on the bottom of the water reservoir 4.
In principle, it would be sufficient to place
the water reservoir 4 underneath the water filter 3 in
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which case the water reservoir 4 must have an adequate
volume, as described.
The water reservoir 4 discharges into a water
outflow 5 at its lowest point. This water outflow 5 is
connected to a continuous-flow heater 2 in which the
water required for the brewing process is heated in
portions.
In order to create a pressure compensation when
filling or emptying the water reservoir 4 and, therefore,
to guarantee its functioning perfectly, there is a vent
pipe 9 on its top side which in this case leads through
the fresh water container 1 to the exterior.
In addition, a backpressure valve 10 is provided
in the water outflow 5 which prevents heated water
flowing through the water outflow 5 into the water
reservoir 4.
A bottom sieve 7 is illustrated in Figure 2
which has sieve webs 12 which run parallel to one another
on two levels, the sieve webs 12 in the relevant levels
being out of phase with one another, so that the
passageways between the sieve webs 12 of the upper level
and those of the lower level can be kept very small.
On the one hand, this grate-like design of the
top and bottom sieves 6, 7 holds the granulate securely,
on the other, the water is restrained, which i9
especially important upon entry of the ~resh water, so
that optimal utilization,, i.e. optimal efficiency, of
the granulate 11 is guaranteed.
In addition, the water filter 3 can be easily
exchanged and the relevant seals are provided in the
transitional area between the fresh water container 1 and
.
_5_ 2061082
the water filter 3 which prevent unfiltered water
entering the water reservoir 4.
In this sense, it may also be preferable to seal
the water reservoir 4 off from the fresh water container
S 1.
.
