Metering device for liquids

A metering device for liquids with a container, which has at least one elastically deformable wall section, and with a metering vessel. The container has an outlet with a withdrawal opening which, corresponding to the liquid to be measured out, is so narrow, that liquid emerges only when the deformable wall section is indented. The metering vessel can be connected detachably with the container, so that it surrounds the withdrawal opening during metering process. While the liquid is being measured out and with the container and the metering vessel in the inverted position, there is a liquid-tight connection between the metering vessel and the container. The very narrow withdrawal opening enables liquid to emerge when the derormable wall section of the container is indented, but prevents any flow of liquid after the metering process is completed and the metering vessel is removed.

BACKGROUND OF THE INVENTION 
The invention relates to a metering device for liquids, "liquids" being 
understood to include also pulpy media here. The metering device has a 
container and a metering vessel, which may consist of a transparent 
material. It may also have graduations, although these are not necessary 
for some embodiments. The container consists either as a whole of an 
elastically deformable material or has at least a wall section, which is 
elastically deformable. 
Metering devices of this type are known, in which liquid can be forced from 
the container through a standpipe into the metering vessel. The standpipe 
extends from the base of the container into the metering vessel by an 
amount required by the specified metering. If the container (in the 
upright position) is compressed, liquid is conveyed into the metering 
vessel and, after the pressure exerted on the container is released, 
sucked back once again up to the height of the standpipe. 
This known metering device has the following disadvantages. It is expensive 
due to the need to install a standpipe and due to a complicated sealing 
process. The use of the device is not hygienic because, at the end of the 
metering process, foreign objects such as dirt particles can reach the 
container together with the liquid, which is sucked back out of the 
metering vessel back into the container. 
Moreover, known metering devices have at least one of the following 
disadvantages; 
complicated manipulations are required at or with the container; 
the precision leaves something to be desired; 
the metering devices are expensive. 
It is furthermore known that a liquid may simply be poured up to a mark 
into a metering vessel, especially a graduated beaker. However, the 
handling is complicated and the metered flow cannot be controlled. 
The present invention is intended to provide a liquid metering device, 
which is free of the above-mentioned disadvantages and simple to operate 
and with which a high metering accuracy can be achieved and with which 
liquid cannot return to the container from the metering vessel. 
SUMMARY OF THE INVENTION 
During the metering process, the metering vessel remains connected 
liquid-tight with the container. The metering process is carried out after 
inverting the unit comprising container and metering vessel, so that the 
container is at the top and the metering vessel at the base. Metering in 
this position is made possible by the very narrow withdrawal opening, 
which permits liquid to escape only when the deformable wall section of 
the container is indented. At the end of the metering process, the upright 
metering vessel is removed from the inverted container. Because of the 
narrowness of the withdrawal opening, liquid cannot escape from the 
container, unless further pressure is exerted on the container. During the 
metering process, no liquid can be sucked back into the container, not 
even when the container expands once again, because the liquid level in 
the metering vessel is separated from the withdrawal opening by an air 
gap. 
As a rule, no special measures are required to vent the container since, 
when the pressure is released, air is aspirated into the container either 
from the metering vessel or, after removal of the metering vessel, from 
the surrounding space. 
With regard to another feature of the invention, the container, while being 
transported, can be shut off by a sealing cap or some other seal, so that 
liquid cannot emerge, even when pressure is exerted on the container. 
Moreover, the metering vessel can be mounted on the container in the 
position intended for the metering process even while the container is 
being transported. 
Another feature of the invention is that a container can be permanently set 
down in a position suitable for the metering process, so that, whenever 
the need arises, only the metering vessel has to be moved. 
Still another feature of the invention is that the container itself can be 
so designed, that is can be set up in its own base in a metering position 
and that there is sufficient space above a support, on which the container 
is resting, for slipping on and for removing the metering vessel. 
Another feature of the invention is that the handling during the metering 
process can be simplified owing to the fact that, through exerting a 
pressure once on the elastically deformable section of wall, only a 
desired portion (metered amount) of the liquid emerges, this being 
adequately precise, for example, in the case of detergents or liquid 
washing agents, for which no high demands are made with regard to the 
accuracy of the metering process, whereas a simplified handling is very 
desirable. 
According to the invention very accurate metering is made possible or 
facilitated owing to the fact that air can emerge as the metering vessel 
is filled. Such a metering procedure is if particular interest for 
pharmaceutical purposes. Liquids can be metered out with high accuracy in 
amounts of, for example, 0.5 or 1 mL. By these means, the tedious counting 
of drops or metering with a pipette becomes superfluous. 
While a reducer, which has a narrow withdrawal opening, can be accommodated 
at the container itself or in its opening, the withdrawal opening can 
instead be provided according to claim 8 in the base of a metering vessel, 
which can be slipped on or screwed on the opening of the container and has 
a removable lid, which is closed during the metering process and opened 
for emptying the metering vessel. 
In another embodiment of the invention, a metering device can be provided, 
which finds application preferably in the pharmaceutical industry and for 
which especially a dome-shaped metering vessel can be screwed over a 
cone-shaped construction onto the opening of a container, generally, a 
medicine bottle. During the metering process, the space remaining between 
the metering vessel and the construction is filled completely, while all 
the air escapes from this space. Compared to other possibilities, such as 
dropper inserts, only very little capital expenditure is required here.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As shown in FIG. 1, a container 1 in the form of a bottle has an opening 2 
with a screw thread 3, which accommodates a reducer 5. Within the reducing 
socket, a withdrawal opening 7 is provided, which partly ends in a 
connecting sleeve 9 of the reducing socket. The opening 2 can be closed 
off by a screw cap 11, which is of importance only for transporting 
purposes and is removed before the metering operation. 
The metering vessel 12 has the shape of a beaker here, which consists of a 
transparent plastic material and is provided with a metering scale 14. The 
metering vessel can be slipped on under some tensions. In a first 
variation, which is shown in the left part of FIG. 1, the opening 2 is 
surrounded by a plastic ring 16, which is, for example, shrunk on and has 
an external diameter, which is larger than that of the screw cap 11. For 
the variation shown in the right part of FIG. 1, the container 1 has an 
annular ring 18, which fulfills the same purpose as the ring 16. 
Before use, the screw cap 11 is removed and the metering vessel is slipped 
on once again. For metering purposes, the container, together with the 
metering vessel 12, is inverted. The container is either completely 
elastic or has at least an elastically deformable wall section. If 
pressure is exerted on the container or the wall section, liquid emerges 
from the withdrawal opening 9 and is filled into the metering vessel up to 
the desired mark of the metering scale 14. As soon as the pressure is 
released, air, which is still in the metering vessel above the level of 
the liquid, is sucked into the container. It replaces the volume of liquid 
that has been removed. The withdrawal opening 7, appropriate for the 
liquid to be metered, is so narrow, that liquid cannot flow out by itself. 
The metering vessel, together with its contents, can now be pulled off 
from the downwards facing opening of the container. A suitable choice of 
dimensions and materials ensures that the metering vessel, even when 
filled with liquid, still remains securely suspended at the container 
opening, yet can be pulled off with a reasonable expenditure of force. 
Instead of with a screw cap, the container can also be closed off in a 
different manner for transporting purposes, for example, by a stopper, 
which is placed in the withdrawal opening, by a cap, which is slipped on 
the connecting sleeve 9 or by a sealing disk, which is glued to the 
underside of the reducing socket, that is, to the side facing the interior 
of the bottle. All of these parts serve to make the transporting of the 
container safe and are removed before the metering operation. 
If it is desirable to have the air escape to the outside while the metering 
vessel is being filled, provisions can be made so that the air can pass 
between the edge of the metering vessel 12 and the ring 16 or the annular 
ring 18, for example, by providing grooves at the edge of the inner wall 
of the metering vessel approximately parallel to the axis of said vessel. 
It is not necessary that this connection be liquid-tight, since the 
metering vessel with its contents does have to be removed, while the 
opening of container 1 is inverted downwards. Then, however, there is no 
danger that liquid can escape at the edge of the metering vessel. 
VARIATION OF THE FIRST EXAMPLE OF THE OPERATION 
The container is shaped (for example, it has a relatively broad concentric 
shoulder) so that it can be placed with the opening facing downwards on a 
stand, the opening of the container being at such a distance from the 
base, on which the stand is resting, that the metering vessel can be 
slipped on and taken off again without difficulty. The metering process is 
simplified owing to the fact that the container does not have to be turned 
upside down and upright once again every time. 
FIG. 2 shows a cross section of a relatively large plastic container 1.2, 
which either is elastically deformable as a whole or is relatively rigid 
and has an elastically deformable wall section 20. The container has a 
base 22 or individual, integrally molded legs, with which it can be placed 
on a support 24. Its opening 2.2 is provided in a part 26 of the wall, 
which is above the horizontal elongation of the base, that is, above the 
support 24, and, moreover, by such a distance, that the metering vessel 12 
can be slipped on and taken off conveniently. Here also, a reducing socket 
5 with a withdrawal opening 7 is provided. The metering vessel 12 can be 
slipped onto an integrally molded ring 28, on which it is held with a 
tension adequate for this purpose. The metering process is carried out by 
exerting pressure on the wall of the container, especially on section 20 
of the wall. Preferably, the container is so narrow in the region of wall 
section 20, that it can be grasped with one hand. The metering process 
proceeds in the manner described above. 
The metering vessel once again may be provided with a metering scale. With 
such large containers, which are to be used, for example, for detergents 
or liquid washing agents, where high accuracy in metering is not as 
important, the metering can also be carried out in such a way, that a 
single indentation of the elastic wall section 20 leads to the delivery of 
the desired amount. For this purpose, the wall section preferably is 
constructed so that it arches to the outside in the state of rest and, in 
contrast to the rest of the wall of the container, is relatively easily 
deformable. The dimensions of the wall sections are such that the desired 
amount is delivered by a single indentation. If one wall section is not 
sufficient for this purpose, two such wall sections may also be provided 
on opposite sides of the container wall. While the container is being 
transported, the opening 2.2 may once again be closed off by a (not shown 
here) screw cap. 
FIG. 3 shows a metering vessel 12.3, especially one of plastic, which is 
equipped in one piece with a screw cap 30 for a container opening. The 
metering vessel has a base 32 with a withdrawal opening 7.3, which is 
partially within a connecting sleeve 9.3. During transport, the connecting 
socket can be closed off by a slip-on cap 34. The metering vessel can be 
closed off by a lid 36, which is slipped on under some tension. 
When it is to be used, the metering vessel is screwed with the help of its 
screw cap 30 onto the opening of a container. The metering process is 
carried out in the manner described for the first example of the 
operation. In the inverted position, the metering vessel is sealed by its 
lid 36. After the container has been returned into its normal position 
(opening at the top), the metering vessel is unscrewed, the lid 36 is 
removed and the contents are poured out. 
This example of the operation is intended especially for measuring out 
pharmaceutical liquids. The container 1.4 normally is a bottle, in the 
opening 2.4 of which a beaker-like plastic reducing socket 5.4 is 
accommodated. From the lower edge 40 of said reducing socket, a 
cone-shaped formation 42 extends upwards (in the position shown in FIG. 
4). At the lower end, it has a relatively steep, truncated conical section 
44, which changes over into a conical section 46 of lesser slope. At the 
peak of the conical section, which protrudes somewhat above the bottle 
opening, there is the narrow withdrawal opening 7.4. The reducing socket 
5.4 is seated with an exterior flange 48 on the edge of the opening 2.4. 
A transparent, dome-shaped formation (metering dome 50) of polyethylene 
with an exterior flange 52, which is rigidly mounted in a perforated screw 
cap 54, is used as metering vessel here. The a metering dome has a 
downwards extending, thin, elastically deformable projection 56, which 
lies against the outer wall of the truncated conical section 44 so as to 
form a seal. This arrangement results, on the one hand, in a metering 
space 58 between the metering dome 50 and the conical formation 42 and, on 
the other, in an annular space 60. Before the metering process, both 
contain air. 
If the wall of the bottle is indented in the inverted position of the 
bottle and metering device, the metering space 58 is filled through 
withdrawal opening 7.4 with liquid. Said metering space is, moreover 
filled completely, air escaping from the metering space with elastic 
deformation of the projection 56 into the annular space 60. The metered 
liquid can be removed after the metering dome 50 has been unscrewed 
(inverted position). 
Different amounts of liquid can be metered out by the use of metering domes 
of different shapes and especially of different heights.