The present invention relates to an apparatus for metering or distribut¬ ing of liquids. The apparatus according to the invention comprises an inner vessel for accomodating the liquid, the volume of which is to be metered, and an outer vessel surrounding the inner vessel and provided v/ith a volume graduation scale. The invention is based on the principle that the volume graduation scale is mounted outside the inner vessel, total internal reflection occuring when liquid is poured into the inner vessel, owing to that the ray of light from a graduation mark being covered by the liquid, by refraction in media with different optical densities is subject to total internal reflection so that it appears to the eye that the volume graduation scale disappears from below as liquid is poured into the vessel. Metering is also facilitated in that during metering it is possible to read the volume graduation scale from above while the apparatus is standing upright, e.g. on a table.

The apparatus according to the invention can be utilized in all areas where it is required to meter small or medium large liquid volumes, e.g. it can be utilized for medicine dosages.

The object of the invention is to achieve an apparatus for metering of liquids into an ungraduated dosage vessel having bottom and side walls defining an upper mouth, at least a portion of one side wall being sub¬ stantially vertical, transparent and arranged for coaction with a graduated scale, ^' placed outside said portion, said scale being separat¬ ed from the outside of the vessel portion by an air gap, whereby light rays from the scale graduations pass through the interface at the inner surface of the vessel wall when it is empty, so that the graduations are visible from the mouth of the vessel, whereas said rays are totally internally reflected at the interface between the inner surface of the vessel wall and the liquid when the vessel is filled with liquid above the graduation mark in question, since the liquid has a greater refract¬ ion index than air, the graduation mark thus being no longer visible from the mouth of the vessel.

Another object of the invention is to achieve an apparatus for metering by arranging the scale on an outer vessel surrounding the dosage vessel whereat in one embodiment both said vessels having tapered side walls.

In a further embodiment of the invention the graduations are arranged on the inner surface of the outer vessel side v/all or the scale may be arranged on the outer surface of the outer vessel side v/all if said v/all is transparent.

The invention will now be described in detail while referring to the attached drawing, which shows the apparatus according to the present invention in a schematic perspective view with partially broken-away portions.

The apparatus according to the invention comprises an outer vessel 1 surrounding an inner vessel 2 with a small gap or slot between them, the liquid to be volumetrically metered being poured into the inner vessel 2. A graduation scale 3 s arranged on the interior side wall of the outer vessel T. The reference numeral k denotes the level of the liquid in the inner vessel 2. If the liquid level h is observed from above in the way indicated in the figure, a boundary ray of light 5 at the interface between the liquid level k and the interior side wall of the inner vessel 2 will be refracted substantially in the way denoted in the figure from the graduation scale- 3.

A ray of light inside this boundary ray of light, e.g. the ray denoted by the numeral 6 in the figure, will on the other hand be totally internally reflected. The light ray 6 from a mark of the section of the graduation scale situated under the mark represented by the ray 5 will by total internal reflection "disappear" and will not be visible to the eye. For these more "central" rays 6 the light thus goes from a graduation mark of the volume graduation scale being arranged out¬ side the inner vessel and with a gap between them, through media of different optical densities in such a way that the ray will be totally internally reflected. Thus the portion of the graduation scale lying under the liquid level will not be visible, which facilitates the meter¬ ing as it is possible to read the graduation scale from above. The in¬ vention thereby eliminates the need of lifting up the vessel to eye level in order to read off the the graduation scale, as with ordinary simple measuring vessels provided with a graduation scale.

In the embodiment of the invention described above the inner vessel 2 is transparent, or has at least a transparent vertical portion through

which the graduation scale 3 can be observed. In this embodiment the outer vessel 1 is not transparent or is opaque and the graduation scale is on the inside surface of the vessel.

Instead of a complete outer vessel a stand or rack can be .used, adapted tc the inner vessel and having a scale interacting with the vertical transparent party of the metering vessel. However, it is also possible to utlize a transparent outer vessel . In the latter case, the gradua¬ tion scale can then be placed on the outer surface of the vessel, al¬ though this is not necessary. In the arrangement shown in the figure, the air space between the outer and inner vessels has been exaggerated for the sake of clarity.

Within the scope of the basic idea of the invention, an outer vessel 1 may, for example, be used as a base unit together with a large number of individual inner vessels 2, which are in turn placed in the outer vessel for filling or metering with a controlled volume.

One skilled in the art will appreciate that the embodiment of the invention described above can be modofied and varied in many ways within the scope of the basic idea for the invention.