Drop dispensers of this kind, as described in WO 02/072444 Al, are used for dispensing liquids in drops. A typical application are pharmaceutical products, for example eye drops, or cosmetics. The drop dispensers usually comprise a flexible container or are designed as a cap or insert for a flexible container. In contrast to drop dispensers for inflexible containers there is no opening to let air from the outside into the container during dispensing.

Background Art Many known drop dispensers of this kind are not easy to use, because the drop dispensing is not pre- cise and not easily controllable. Many times the size of the drops is not correct because it is dependent on the kind and the state of the liquid, the position of the dispenser, the speed of the dispensing and/or the pres- sure applied to the container. In addition, because of the bad controllability the user might not be able to dispense the right number of drops. When used for pharma- ceutical products this results in wrong dosages, which makes known dispensers unsuitable for certain applica- tions where a correct dosage is essential. These problems are especially significant, if the drop dispensers are used by elderly people with reduced cognitive and motoric skills. In many cases manufacturing costs of known drop dispensers are unnecessary high because they comprise many parts and in particular parts which cannot be easily produced by efficient processes, as for example by injec- tion molding.

Disclosure of Invention A problem to be solved by the present inven- tion lies therefore in providing a drop dispenser which avoids the problems described above at least partially.

This problem is solved by independent claim 1 by providing a drop dispenser which comprises at least one throttling passage and a delivery passage through which the contents must pass before being dispensed, wherein the at least one throttling passage enters later- ally into the delivery passage.

This has the advantage, that during dispens- ing there are turbulences after the throttling passage, which assure that the drop forms controllably and does not drop away early due to liquid forming a jet or spout.

A further problem to be solved by the inven- tion lies in providing a method for producing a drop dis- penser faster, more precise and at a lower price.

This problem is solved by independent claim 14 by creating at least one throttling passage at least partially by laser drilling.

This has the advantage, that the throttling passage can be made in a short time and with a small and very precisely definable diameter.

Brief Description of Drawings Further preferred features and aspects of the present invention are described in the dependent claims as well as in the following description, which makes ref- erence to the enclosed figures. These figures show: Fig. 1 a preferred embodiment of a container with a drop-dispensing insert according to the invention in a vertical cross-sectional view, Fig. 2 the drop-dispensing insert of fig. 1 in a vertical cross-sectional view,

Fig. 3 the drop-dispensing insert of fig. 1 in a side view, Fig. 4 a three dimensional, partially sec- tional view of the container with drop-dispensing insert of fig. 1, Fig. 5 the throttling passages of a preferred embodiment of the invention, in a partial, cross- sectional view, Fig. 6 the throttling passage of a further preferred embodiment of the invention, in a partial, cross-sectional view, Fig. 7 the throttling passage of a further preferred embodiment of the invention, in a partial, cross-sectional view, Fig. 8 the throttling passage of a further preferred embodiment of the invention, in a partial, cross-sectional view.

Best Mode for Carrying Out the Invention A vertical cross-sectional view of a pre- ferred embodiment of container with a drop-dispensing in- sert 3 according to the invention is shown in fig. 1. The drop-dispensing insert 3 is also shown in fig. 2 in a cross sectional view and in fig. 3 in a side view. The drop-dispensing insert 3 is preferably made from plastic, using an injection molding process. For dispensing liquid in drops, the container 5 is held with the spout down- wards and is squeezed to pressurize its content. The con- tainer 5 is flexible, for example a flexible bottle or a tube. Due to the pressure the liquid passes through the two throttling passages 1 and into the delivery passage 2. The two throttling passages 1 enter laterally and dia- metrically opposed into the delivery passage 2. During dispensing there are turbulences in the area where the liquid enters into the delivery passage 2. Due to these turbulences the liquid is decelerated and there is no jet

or spout, which could distract the drop formation at tear-off edge 4, in particular by causing the drop to drop away before it has reached its predetermined size.

The delivery passage 2 is substantially conical and has its largest diameter at the distal end of the drop dis- penser. The drop-dispensing insert 3 is designed elon- gated, as a cannula. Opposite to its distal end it has a shaft, which fits into a cylindrical opening or socket of the container 5 for fixing the insert to the container.

At the container side end of the throttling passages 1 the diameter of the drop-dispensing insert 3 is smaller than the diameter of the opening, such that liquid can pass between the inner wall of the opening and the out- side of the drop-dispensing insert 3 to the throttling passages 1. The container 5 comprises a thread 6, such that the container 5 can be closed by screwing on a cap.

In a preferred embodiment the container is a tube, as al- ready mentioned; the precise metering and the prevention of jets by the drop dispenser according to the invention is particularly useful with tubes which are generally less stable against squeezing than other types of flexi- ble containers.

A three dimensional, partially sectional view of the container 5 with drop-dispensing insert 3 in the embodiment of figs. 1 to 3 is shown in fig. 4.

The throttling passages of the embodiment of figs. 1 to 4 are shown in fig. 5 in a partial, cross- sectional view. The throttling passages 1 are perpendicu- lar to the axis of the delivery passage 2. The throttling passages 2 are substantially cylindrical and both on the same straight line. They are preferably created by laser drilling. Laser drilling has the advantage that it is very precise, allows small diameters even at a high drilling depth and is relatively fast. Two diametrically opposed throttling passages 1 as shown in fig. 5 can be drilled within the same procedure step. For laser drill- ing the drop-dispensing insert 3 should be fabricated

from a suited material, in particular plastic which suf- ficiently absorbs the laser's energy, for example due to a dark color. The throttling passages 1 can also be made during the injection molding process, using conventional drilling, or by a combination of the above mentioned methods. The throttling passages 1 have preferably a di- ameter of less than 100ism. Instead of two throttling pas- sages there can also be only one, three, four or even more throttling passages. Since these passages are"in parallel"regarding the fluid flow the diameter of the individual throttling passages 1 has to be smaller, if there are more throttling passages 1. The throttling pas- sages 1 are preferably evenly spaced along a circumfer- ence of the delivery passage 2.

An alternative arrangement of a throttling passage is shown in fig. 6. The throttling passage 1 is inclined, such that the velocity vector of the fluid has a component opposite to the dispensing direction, wherein the dispensing direction is the direction towards the distal end of the drop-dispensing insert 3, along the axis of the drop-dispensing insert 3.

A further alternative arrangement of a throt- tling passage is shown in fig. 7. The throttling passage 1 is also inclined, but in opposition to fig. 6 the ve- locity vector of the fluid has a component in direction of the dispensing direction. Accordingly, the term lat- eral is understood to comprise such embodiments as well wherein the throttling passage (s) enter the delivery pas- sage 2 at an angle, but still through the lateral wall thereof.

An alternative form of a throttling passage 1 is shown in fig. 8. The throttling passage 1 is conical, with its smallest diameter at the connection to the de- livery passage 2. This embodiment is particularly suited, if the throttling passage 1 is to be created during in- jection molding or by conventional drilling. The conical form has the advantage that the slider used in the injec-

tion molding process or the drill used for conventional drilling does not break as easily. The disadvantage of such a drilling is, that the smallest diameter of the throttling passage 1 cannot be defined as precise. If only a first section of the throttling passage 1 is cre- ated in such a way, the second, smaller section can still be created using a laser, which assures a precise minimum diameter. Instead of a conical shape, or in combination therewith, a cylindrical shape with stepwise reduced di- ameter of the cylindrical sections is possible as well.