Dispensing – With filter – Internally extended outlet pipe
Reexamination Certificate
1998-04-16
2001-06-26
Shaver, Kevin (Department: 3754)
Dispensing
With filter
Internally extended outlet pipe
C222S464200
Reexamination Certificate
active
06250508
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns an apparatus for withdrawing a liquid from a closed container. The container is provided with a withdrawal connection portion through which the liquid is taken from the container and passed for further use thereof. The container is in a fluctuating position in space if it is part of a portable piece of equipment.
The invention aims to make it possible to take a liquid from a closed container when the container is in any position in space so that the liquid withdrawn from the container can be used in the appropriate fashion and in a trouble-free manner.
2. Related Art
It is known for a liquid to be discharged downwardly from a rigid container through a discharge connection portion or to be withdrawn upwardly or laterally by means of a tube or hose which projects into the container. The discharged flow of liquid is bubble-free and uninterrupted as long as the liquid completely covers the discharge connection portion or as long as the end of the tube completely dips into the liquid. Those conditions can be easily observed when dealing with a container which is in a fixed position in space. The liquid in the container can be virtually completely withdrawn therefrom.
In portable pieces of equipment on the other hand a rigid liquid container can adopt any position in space. As long as one of the conditions specified for a container involving a fixed position in space is met, a bubble-free and uninterrupted flow of liquid can also be taken from a container whose position in space fluctuates. It is however not possible for the liquid in the container to be completely withdrawn therefrom.
It is further known to dispose in a rigid container a foil bag which contains the liquid and which collapses to the extent that liquid is taken from the foil bag (collapsible bag). Experience has shown that the liquid can no longer be withdrawn from the bag as soon as the foil comes to bear against the discharge connection or the end of the tube or hose. Experience has shown that this can occur before the foil bag is empty.
Accordingly an object of the invention is to provide an apparatus with which a liquid can be almost completely withdrawn from a closed container in a trouble-free manner, the container being provided with a withdrawal connection portion, containing a liquid and involving a position that fluctuates in space.
SUMMARY OF THE INVENTION
According to the invention that object is attained by a storage medium which has open-pore porosity and which is in the form of an integral body. The storage medium is disposed within the container at least in the region of the end of the withdrawal connection portion. It touches the liquid at least at times. For total withdrawal of the liquid the storage medium preferably bears against a part of the inside wall of the container.
The storage medium can be disposed outside the withdrawal connection portion in front of the end thereof and can surround the withdrawal connection portion which projects into the container, at least over a part of the length of the withdrawal connection portion, within the container. In another embodiment the storage medium fills the major part of the container volume. In a further embodiment the storage medium is disposed substantially in the interior of the withdrawal connection portion at the end thereof. In a further construction the storage medium is disposed in the interior of the withdrawal connection portion at the end thereof and surrounds the withdrawal connection portion which projects into the container, at least over a part of its length.
It may be desirable to provide a cavity in the storage medium in the region of the end of the withdrawal connection portion.
The storage medium is either a body of stable shape comprising sintered powder or a wadding, a fleece, a knitted portion or a woven portion of fibres or an open-pore body, for example a sponge. It may also be a non-sintered powder which completely fills a part of the container volume, in which case the partial volume filled with powder is separated from the remaining volume of the container by a liquid-permeable wall.
The powder or the fibres forming the storage medium may comprise plastic material, ceramic, glass, metal or a natural substance.
Powders of polyolefin or polyester are suitable as plastic powders for example. Powders of ceramic or glass, for example, of Al
2
O
3
, SiO
2
, TiO
2
and Na-Al-silicate are also suitable. Metal powders may comprise Ni, Al, high-quality steel or bronze. The particle size is 0.5 to 500 &mgr;m.
Suitable fibres are those comprising plastic material, for example polyolefin or polyester, glass or metal or metal alloys, for example steel. The fibre diameter is 5 to 100 &mgr;m.
The withdrawal connection portion may be a rigid tube or a flexible hose. Instead of passing through the cover or through the bottom the withdrawal connection portion may pass through the container wall into the interior thereof at any location. The end of the withdrawal connection portion possibly terminates flush with the inside wall surface of the container. In that case the storage medium is fixed to the container wall in front of the end of the withdrawal connection portion.
If the container is rigid and if a considerable reduced pressure is not to occur in the container the container is provided with a vent valve which possibly operates automatically.
The storage medium is permeated by capillaries and serves as a pre-storage means for the liquid. It constantly holds a certain amount of the liquid in the proximity of the end of the withdrawal connection portion, even if the end of the withdrawal connection portion itself is above the level of liquid in the container. When the container is in that spatial position the liquid is withdrawn from the storage medium. As soon as the spatial position of the container changes and the storage medium is again in contact with liquid, it sucks itself full again with liquid.
The storage medium preferably fills only a part of the container volume.
The apparatus according to the invention has the following advantages:
it permits the withdrawal connection portion to be supplied with liquid, irrespective of position, as long as the maximum possible volume flow in the withdrawal connection portion is less than the maximum possible volume flow of the liquid in the storage medium,
the liquid can be withdrawn, free from gas bubbles, the storage medium serving as a bubble barrier,
the liquid can also be withdrawn virtually completely and in a trouble-free manner from a foil bag,
the storage medium acts as a filter for the liquid, and
the liquid can be virtually completely withdrawn from the container by means of a storage medium which bears against a part of the inside wall surface of the container.
The apparatus according to the invention is a particularly attractive proposition for the storage of a medicament dissolved in a solvent, for producing an aerosol for inhalative application. Suitable solvents are for example water or ethanol or mixtures thereof. Suitable medicaments are for example Berotec, Atrovent, Berodual, Salbutamol, Combivent, Oxivent, Ba 679, BEA 2108 and others.
The apparatus according to the invention can be used in a particular embodiment as an active substance deposit for atomisers, as are disclosed for example in PCT application WO91/14468 or PCT/EP96/04351. Even when withdrawing small amounts of liquid in the range of between 10 and 40 microliters the apparatus according to the invention guarantees that the solution is taken in a bubble-free condition from the storage medium which is generally of a volume of between 2 and 6 milliliters.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus according to the invention will now be described in greater detail by way of example with reference to the drawings.
FIG. 1
is a view in axial section through a cylindrical container
1
with a flat bottom, which is closed by a cover
2
. A vent valve
3
is mounted in the cover. A withdrawal connection portion
4
is in
Geser Johannes
Kladders Heinrich
Boehringer Ingelheim International GmbH
Deal David
Shaver Kevin
Sterne Kessler Goldstein & Fox P.L.L.C.
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