Insert for a water purifier

Described is an insert for a water purifier comprising substantially cylindrical side walls (9) with a filter top (16) and a filter bottom (10) at the end thereof, and with an annular sealing means (12, 22) secured to the upper end of the side walls (9). In order to increase the volume and in particular the length of the flow path of the liquid to be purified, through the purification agent, it is provided in accordance with the invention that the insert comprises a distributor and a cup portion (11) connected thereto, which respectively have at least a guide tube (13, 17) extending into the interior of the insert and an annular flange (12) for securing to the other annular flange (22), that the guide tubes (13, 17) are of different diameters and in the assembled condition are in concentric relationship with each other, that the upper annular flange (22) is secured to the filter top (16) of the distributor, said filter top having an end wall (21) and filter slots (23) in a cylindrical wall (20), an that filter means are provided at the inner guide tube (13).

The invention relates to an insert for a water purifier comprising 
substantially cylindrical side walls with, at the ends thereof, a filter 
top and a filter bottom and with an annular sealing means which is secured 
to the upper end of the side walls. 
German laid-open application (DE-OS) No. 29 19 901 discloses a water 
purifier of the kind set forth in the opening part of this specification. 
In that purifier, an insert is releasably connected to a hopper or 
funnel-like portion, while filter-like closure members are disposed at the 
two mutually oppositely disposed ends of the insert. It has been found in 
the past in earlier inserts that the filter-like openings which are 
provided in the horizontal plane, in particular the upper filter means of 
the insert, suffered from wetting or partial clogging with the result that 
the flow of water through the space which was defined by the filter 
members and which was filled with purifying agent was considerably slowed 
down or interfered with. Therefore, in the water purifier disclosed in the 
above-mentioned DE-OS, disposed at the upper end of the insert is an 
upwardly projecting vent tube which is provided with openings at its top. 
The vent tube may also be formed in the manner of a handle in order to 
enhance handling of the upper filter member. The openings at the top of 
the vent tube are disposed above the level of liquid so that there is then 
no longer any clogging of the upper filter, with the result of interfering 
with the flow of water through the arrangement. Thus, the liquid to be 
purified, generally water, can flow through the filter members and the 
insert more easily. 
The aim of the present invention is to achieve further improvements in 
regard to the insert of the water purifier. 
To improve an insert of the kind set forth in the opening part of this 
specification, the object of the present invention is to increase the 
volume and in particular the length of the flow path of the liquid to be 
purified, through the purification agent. In that connection, it would be 
desirable if the upwardly projecting vent tube of the known insert could 
be omitted. 
In accordance with the invention, to provide such an insert and to attain 
the above-indicated object, it is provided that the insert comprises a 
distributor and a cup portion connected thereto, which respectively have 
at least a guide tube extending into the interior of the insert and an 
annular flange for securing to the other annular flange, that the guide 
tubes are of unequal diameter and are arranged concentrically relative to 
each other in the assembled condition, that the upper annular flange is 
secured to the filter top of the distributor, said filter top having an 
end wall and filter slots in a cylindrical wall, and that filter means are 
provided at the inner guide tube. The insert according to the invention no 
longer comprises, like the above-described known water purifier, a simple 
cup which is closed at top and bottom by filter or sieve members in such a 
way that the purification agent is retained by the filter slots, but 
instead the novel insert comprises two specially formed components, namely 
the component referred to as the distributor and the component referred to 
as the cup portion. Each of those two components has a guide tube which 
extends into the interior of the insert. The guide tubes are of different 
diameters and are disposed in concentric relationship when they are in the 
assembled condition. In order to seal off the insert relative to the 
exterior, the distributor and the cup portion each carry an annular 
flange, which flanges can be secured together, and can preferably be 
sealed. Arranged on the distributor at the top thereof is a filter or 
sieve top member and arranged thereon is the upper annular flange. The 
filter top itself has a cylindrical wall with filter slots, and an end 
wall. Besides the filter means on the top of the filter top, there is a 
filter means on the inner guide tube. 
Advantageously, the two guide tubes which project into the interior of the 
insert and which are arranged concentrically are provided in the manner of 
flow chicanes. In other words, that enlarges the flow path of the liquid 
to be purified, by a multiple, in comparison with the height of the whole 
insert. 
The purification agent comprises for example a granulate or also activated 
carbon. Preferably, a suitable purification agent for water for industrial 
use is an activated carbon which is made substantially germ-free by a 
surface treatment, for example by silver plating the surface thereof. 
However, it is also possible to use other granulates such as for example 
ion exchangers and the like. 
When the insert is connected to a funnel-like portion of the water 
purifier, it will be apparent to the final user that the fresh water which 
is poured into the funnel-like portion at the top is to flow through the 
sleeve and thus the purification agent. Although the flow speed may not be 
excessive, it is understandably undesirable for the flow to be impeded by 
blocked filters or sieves. 
The interchangeability of the whole insert together with the purification 
agent has the advantage that the final user does not need to come into 
contact with the purification agent and therefore germs cannot get into 
the loose grains. That provides for maximum hygiene, in particular 
avoiding undesirable infection. For that purpose however, it must be 
possible for the insert filled with the purification agent to be fitted as 
a unit into a per se known funnel portion and to be removed therefrom 
after the purification action has become exhausted, to be replaced by a 
new insert which is filled with fresh purification agent. 
Although the known insert whose flow path was equal to the height of the 
insert itself provided really good results, the effect is considerably 
enhanced by the multiple increase in the distance which has to be covered 
by the water to be purified in flowing through the purification agent. 
The novel insert does not have the upwardly projecting vent tube of the 
known insert. Instead, the novel insert according to the invention has a 
filter or sieve top or cover of a particular configuration, more 
specifically, it has an end wall which in the position of use is disposed 
in a horizontal plane and a cylindrical wall which adjoins the edge of the 
end wall in a downward direction. The above-mentioned filter slots are to 
be found in the cylindrical wall and possibly in part also in the end 
wall. When, in the manner described above, the annular flange on the 
filter top is arranged at the lower end of the cylindrical wall which has 
the slots therein, and is in direct contact with the other annular flange 
which is disposed at the upper end of the cup portion, then to avoid 
clogging of the filter slots, it is possible to provide that only a small 
part or none of the liquid penetrates into the space in the filter top, in 
use of the arrangement. In other words, the space in the filter top 
between the end wall thereof and the upper annular flange is filled with 
air, and any liquid which gets in will initially enter in the lower region 
of the slots so that the air can escape in the upper region thereof, 
consequently eliminating clogging or flooding thereof. 
The annular flanges and in particular the lower annular flange which is 
mounted to the cup portion serves at the same time as a sealing means 
between the funnel-like portion which in use is filled with liquid and the 
insert or the collecting container which is disposed beneath the funnel 
member. Although that arrangement does not provide an absolute seal for 
the annular flanges are only laid on the central opening in the 
funnel-like portion, practical experience has shown however that the 
sealing action which is achieved in that way is fully sufficient so that 
the liquid in the funnel portion can only reach the collecting container 
by flowing through the insert and the purification agent. 
It is advantageous in accordance with the invention if the filter or sieve 
means are arranged at the top and/or bottom on the inner guide tube. It 
will generally be preferred for the filter means to be disposed on the 
inner guide tube at the bottom thereof. That gives an increase in volume 
for the filter material. The filter material or the purification agent is 
disposed, as already mentioned, in and around the guide tubes in the 
region of the cup portion. In that way, the arrangement provides a flow 
path for the liquid, which first passes into the filter cover in the top 
part outside the outer guide tube which is mounted to the distributor, and 
flows downwardly on the outside wall of the outer guide tube, in the 
entire annular space between the outer guide tube and the outer wall of 
the cup portion. After that preliminary purification operation, the 
direction of flow is turned through 180.degree. at the lower end of the 
outer guide tube and the liquid now flows outside the inner guide tube and 
inside the outer guide tube into the annular space which is formed between 
the two guide tubes, upwardly to the end of the inner guide tube, where 
the direction of flow again changes through about 180.degree. so that the 
liquid can finally flow downwardly through the inner guide tube, and can 
be discharged thereat. 
If now the filter or sieve means are arranged on the inner guide tube at 
the bottom thereof, it will be apparent that purification agent is also 
available, in the space within the inner guide tube, over the 
last-described third of the flow path of the liquid which is to be 
purified. 
However, it may also be desirable if, in accordance with the invention, the 
filter or sieve means has straight filter slots which are arranged in an 
annular array at the upper end of the inner guide tube which is closed at 
its top. In that case, the liquid distribution effect is improved for the 
liquid or water which flows up on the outside of the inner guide tube 
cannot then, as in the last-described case, flow over the edge and flow 
through paths that it seeks out itself, down into the space within the 
inner guide tube, but instead the liquid to be purified must flow through 
the slots at the upper end of the inner guide tube. The annular 
distribution of the preferably straight slots permits the incoming flow of 
water or liquid to be made uniform. 
However, the possibility can also be envisaged that a filter or sieve means 
is disposed on the inner guide tube both at the top and at the bottom, for 
example being, at the top, the annular array of straight filter slots and 
at the bottom another kind of filter or sieve member. In that case, a 
different purification agent may be used in the interior of the guide 
tube, from that outside. In other words, that arrangement permits 
different filter agents to be disposed separately in the insert. If for 
example only the inner guide tube is filled in a first filling operation, 
then, in a second filling operation, the double annular space outside the 
inner guide tube, which has already been filled, and inside the outside 
wall of the cup portion, can be filled with the other material. 
In another advantageous embodiment of the invention, the slots in the 
filter top are straight and arranged in an annular array, and preferably 
the slots in the filter bottom are curved and are arranged on concentric 
circular lines. While previously reference was made to the filter means on 
the inner guide tube, the filter slots on the filter top or cover are now 
being discussed. They may also be of a straight configuration and arranged 
in an annular array. The shape of the filter top with end wall and 
cylindrical side wall which extends from the end wall to the upper annular 
flange has already been discussed. It is preferable for the straight slots 
to be arranged in the cylindrical wall, the direction of the straight 
slots coinciding with the longitudinal axis of the cylindrical wall. 
However, the direction may also be turned through 90.degree. so that the 
slots extend on circular lines at the periphery of the cylindrical wall. 
Less desirable is the arrangement of slots in the end wall alone because 
in that case the problem of clogging and flow restriction occurs again. 
The combination of short straight slots projecting inwardly from the edge, 
in the end wall of the filter top, with slots in the cylindrical wall, has 
been found to be advantageous. 
The invention further provides that the outer guide tube is fixed to the 
filter top. In regard to the above-described liquid flow path, it was 
already assumed that that feature was to be found therein, but it is not 
absolutely necessary. By virtue of mounting the outer guide tube to the 
filter top, the liquid to be purified, which enters from above through the 
slots in the filter top, is first obliged to flow downwardly into the 
annular space between the outer guide tube and the outside wall of the cup 
portion. 
In addition, the cup may then be easily filled from above. On the 
assumption that either the filter means are arranged at the lower end of 
the guide tube or, (if they are arranged at the top and the inner guide 
tube is already filled with another purification agent), the operation of 
filling the cup portion from above as far as the edge, that is to say, up 
to the level of the lower edge flange, requires less attention to be paid 
thereto. In that case, the distributor with the outer guide tube is 
inserted from above, fitted into position and connected by ultrasonic 
welding, that is to say, the upper and lower annular flanges are sealingly 
joined together by ultrasonic welding. The use of adhesive is not 
preferred when operating in the foodstuffs field (drinking water). 
It is also desirable in accordance with the invention if the length of the 
two guide tubes is approximately equal and if the length of the inner 
guide tube is equal to the height of the side wall of the cup portion. 
That arrangement not only favours the above-described advantageous method 
of filling the cup portion, but, due to the length of the inner guide 
tube, it also ensures that the annular space in the filter top is not 
filled with purification agent and therefore preferably remains filled 
with air so that the flow through the slots in the filter top is 
maintained without impediment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 shows the entire apparatus for the purification of liquid, 
preferably water, comprising a funnel-like portion 1 and a sleeve 4 which 
is integrally formed thereon on the underside thereof. Provided on the 
outer lower edge of the portion 1 is a flange 2 for bearing against the 
edge of a container (not shown). Formed on the funnel portion 1 at one 
side, being the side on the left in FIG. 1, is an inclinedly disposed side 
plate or bar 3 which, upon actuation thereof, permits the portion 1 with 
the sleeve 4 formed integrally thereon to be pivoted upwardly about the 
pivot point indicated approximately at 5 by the cross. By virtue of that 
arrangement, the liquid which has already been purified can be poured out 
directly with the funnel portion 1 still fitted on the pouring container 
(not shown). 
At the top, at its transition to the portion 1, the sleeve 4 which is 
formed integrally on the underside of the portion 1 at the centre thereof 
is provided with a support step 6, by virtue of an enlargement in its 
configuration. However, the annular enlargement is not absolutely 
necessary, but is suitable for the use of earlier inserts and does not 
interfere with the use of the insert according to the invention. 
In the embodiment illustrated herein, the sleeve 4 is of such a 
configuration as to be slightly conically tapering in a downward 
direction. At its lower end, it has a short, horizontally inwardly 
projecting edge or rim 7 which projects inwardly by a few millimeters on 
the inside of the wall of the sleeve 4, in order to provide a support 
means which extends around the interior of the entire periphery of the 
sleeve. The support means could also be formed by individual projections 
or by a crossshaped support surface. 
The cup-shaped insert 8 is to be fitted into the sleeve 4. 
The insert 8 comprises the cup portion 11 which in turn comprises the 
approximately cylindrical outside walls 9, the filter or sieve bottom 10, 
the lower annular flange 12 and the inner guide tube 13. In this 
arrangement, in accordance with the construction shown in FIG. 5, the 
bottom 10 comprises an annular wall which is impervious to fluid and the 
circular sieve or filter member 14 which is disposed at the bottom 
centrally in the region of the inner guide tube 13. The member 14 may 
comprise for example plastics material and may have curved filter slots 
which are arranged on concentric circular lines. As shown in FIGS. 5 and 
9, the inner guide tube 13 is of the same length as the height H (see FIG. 
9) of the side wall 9 of the cup portion 11. 
The insert 8 further comprises the distributor which is generally denoted 
by reference numeral 15. In its upper portion, it comprises the filter or 
sieve top 16 and the outer guide tube 17 which is mounted thereto and 
which extends into the interior of the insert 8. The guide tube 17 is open 
at its lower edge 18. In the construction shown in FIG. 5, the inner guide 
tube 13 is also open at its top, but in the construction shown in FIG. 6 
the inner guide tube 13 is closed at its top by the top or cover 19. The 
inner guide tube 13 is also to be assumed to be open at its top in all 
other Figures of drawing, including in FIG. 3, apart from in FIG. 6. 
In the assembled condition, in particular in the views shown in FIGS. 3 and 
7, it will be seen that the guide tubes 13 and 17 are of different 
diameters and are arranged in concentric relationship with each other. 
The top or cover 16 comprises a cylindrical wall 20 which is closed 
upwardly by a preferably flat end wall 21. Mounted on the side of the 
cylindrical wall 20 which is in opposite relationship to the end wall 21 
is a radially outwardly extending upper annular flange 22 which, as shown 
in FIG. 8, is bevelled or inclined somewhat downwardly so that it matches 
the similarly bevelled or inclined lower annular flange 12 which, in the 
view shown in FIG. 1, bears sealingly on the bottom of the portion 1. 
After the components have been assembled, the two flanges 12 and 22 are 
sealingly joined together in the region of their annular surfaces by 
ultrasonic welding. 
The insert 8 in accordance with the invention has three, or at least two, 
different sieve or filter means. 
1. The first filter means 14 is disposed in the filter bottom 10, as can be 
seen for example from FIG. 5. 
2. The second filter means is disposed in the top or cover 16 and comprises 
straight filter slots 23 which are disposed in an annular array. The 
direction of the slots 23 is parallel to the axial direction of the larger 
and inner guide tubes 17 and 13; as shown in FIG. 4, they begin at the 
inner edge 24 of the upper annular flange 22 and preferably terminate at a 
spacing from the circular periphery of the upper end wall 21. In another 
embodiment (not shown), the slots 23 may also extend as far as the 
circular edge of the end wall 21 while in another third embodiment they 
may preferably even extend by a portion radially from the outer periphery 
of the end wall 21 towards the centre point thereof, but only over about 1 
to 3 millimeters. Preferred however is the embodiment which is shown in 
FIG. 4. 
3. A third filter means 25 is provided at the upper end of the inner guide 
tube 13 which, in the embodiment shown in FIG. 6, is closed at its top by 
the wall portion 19. That filter means 25 comprises straight filter slots 
which are disposed in a peripheral annular array. It is also possible here 
to envisage filter slots of a different configuration, and possibly also 
rows of holes, although this only ever concerns the construction shown in 
FIG. 6 wherein the inner guide tube 13 is closed upwardly by the wall 
portion 19. In this case, the lower circular filter member 14, as shown in 
FIG. 5, may be omitted or additionally provided. 
Therefore, the insert 8 in accordance with the invention is provided at 
least with two sieve or filter means 14 and 23, and possibly also with the 
sieve or filter means 25, or, with the lower filter means 14 being 
omitted, with the upper filter means 25 on the inner guide tube 13 only 
instead of the lower filter means 14.