APPARATUS FOR DISPENSING A LIQUID

Abstract

An apparatus for dispensing a liquid into one or more cavities of one packaging shells for ophthalmic lenses, comprises a dispenser block, a dispenser head separate from the dispenser block. The apparatus further comprises one or more tubes connecting the dispenser block and the dispenser head. Additionally, the dispenser block comprises a reservoir for the liquid to be dispensed, and one or more dosing pumps for conveying the liquid from the reservoir to the dispenser head. The dispenser head comprises one or more dispensing tips detachably arranged on the dispenser head, each of the dispensing tips being in fluid communication with the dispenser block by a separate one of the one or more tubes.

Claims

1. Apparatus for dispensing a liquid, in particular a saline solution, into one or more cavities (1) of one or more packaging shells for ophthalmic lenses, comprising: a dispenser block (2), a dispenser head (3) separate from the dispenser block (2), the dispenser head (3) being arranged spaced apart from the dispenser block (2), and one or more tubes (4) connecting the dispenser block (2) and the dispenser head (3), wherein the dispenser block (2) comprises a reservoir (20) for the liquid to be dispensed, and one or more dosing pumps (21) for conveying the liquid from the reservoir (20) to the dispenser head (3), and wherein the dispenser head (3) comprises one or more dispensing tips (30) detachably arranged on the dispenser head (3), each of the one or more dispensing tips (30) being in fluid communication with the dispenser block (2) by a separate one of the one or more tubes (4).

2. Apparatus according to claim 1, further comprising one or more tip connectors (31) which are fixedly arranged on the dispenser head (3), wherein each of the one or more dispensing tips (30) is detachably mounted to a corresponding one of the one or more tip connectors (31), and wherein the dispensing tips (30) and the tip connectors (31) have fluid fittings forming a leakage-free connection between the respective dispenser tip (30) and the corresponding tip connector (31) when being connected with one another.

3. Apparatus according to claim 2, wherein the one or more tip connectors (31) are fixedly arranged on a connector rail (33) arranged on the dispenser head (3).

4. Apparatus according to claim 1, wherein the one or more dosing pumps of the dispenser block (2) are precision dosing pumps (21), in particular micro annular gear pumps.

5. Apparatus according to claim 1, further comprising a storage container pump (5), in particular a peristaltic pump, for conveying the liquid from a storage container (6) to the reservoir (20).

6. Apparatus according to claim 1, wherein the reservoir (20) is sealed against leakage of liquid, and wherein the reservoir (20) comprises an pressure compensation pipe (22) extending from the interior of the reservoir (20) to the ambient environment for pressure compensation in the interior of the reservoir (20), the pressure compensation pipe (22) comprising a sterile filter (23) arranged therein for avoiding contamination of the liquid in the reservoir (20) with foreign organic or inorganic matter by air passing through the pressure compensation pipe (22) into the reservoir (20).

7. Apparatus according to claim 1, wherein the dispenser block (2) comprises a first liquid level sensor (24) for determining an operational liquid level (26) in the reservoir (20).

8. Apparatus according to claim 7, wherein the dispenser block (2) further comprises a second liquid level sensor (25) for determining a maximum liquid level in the reservoir (20) to prevent overflow of the reservoir (20).

9. Apparatus according to claim 8, further comprising a frame (7), with the first liquid level sensor (24) and the second liquid level sensor (25) being fixedly mounted to the frame (7), particularly outside of the reservoir (20).

10. Apparatus according to claim 7, wherein each of the one or more dispensing tips (30) has a dispensing opening (34) at the lower end of the dispensing tip, with the dispensing opening (34) being arranged at the same level as the predetermined operation liquid level (26) in the reservoir (20) determined by the first liquid level sensor (24).

11. Apparatus according to claim 1, further comprising a reservoir inlet pipe (28) connected to a storage container (6) and to the reservoir (20), and further comprising a particle filter (27) arranged in the reservoir inlet pipe (28) to prevent particles from entering the reservoir (20) when the liquid is transported from the storage container (6) to the reservoir (20).

12. Apparatus according to claim 11, further comprising a bubble sensor (29) arranged at or in the reservoir inlet pipe (28) for determining when the storage container (6) is getting empty.

13. Apparatus according to claim 10, wherein each of the one or more dosing pumps (21) comprises a controller configured to dispense a predetermined amount of liquid through the dispensing opening (34) of the respective dispensing tip (30) into the cavity (1) of the packaging shell, and further configured to thereafter retract the liquid from the dispensing opening (34) in the respective dispensing tip (30) to a predetermined level above the respective dispensing opening (34) to avoid unintentional spilling of liquid from the respective dispensing tip (30).

14. Packaging line for producing primary ophthalmic lens packages comprising a packaging shell containing in a cavity (1) thereof an ophthalmic lens immersed in a storage liquid, and a cover foil sealed to the packaging shell around the cavity (1), wherein the packaging line comprises a transport path for the packaging shells along which a plurality of packaging stations are arranged, a first packaging station for placing the ophthalmic lens into the cavity (1) of the packaging shell, a second packaging station in which the storage liquid is dosed into the cavity (1) of the packaging shell, and a third station in which the cover foil is placed onto the packaging shell and sealed to the packaging shell around the cavity (1), wherein the second packaging station comprises an apparatus according to any one of the preceding claims, with the separate dispenser head (3) having the one or more dispensing tips (30) attached thereto being arranged above the transport path while the dispensing block (2) is arranged laterally adjacent to the transport path.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Further details and advantages of the invention will become apparent from the following description of exemplary embodiments of the invention with the aid of the drawings, in which:

[0053] FIG. 1 schematically shows an apparatus according to one embodiment of the invention;

[0054] FIG. 2 shows a further embodiment of the apparatus according to the invention;

[0055] FIG. 3 is an enlarged view of the peristaltic pump and its drive (detail A of FIG. 2); and

[0056] FIG. 4 is an enlarged view of a Luer lock fitting between a dispenser tip and its corresponding tip connector.

DETAILED DESCRIPTION

[0057] As used in this specification, the term saline solution comprises any type of saline solution in which the ophthalmic lens, in particular a contact lens, such as a soft contact lens, or an intraocular lens, may be immersed in the cavity of the lens packaging shell. Such saline solution generally involves a sodium chloride basis and may include additives such as buffers or lubricating agents.

[0058] A dosing cycle is the process of dispensing a volume of liquid in the cavity of the packaging shell. Several dosing cycles may occur, such as a first dosing cycle of saline solution and a second dosing cycle of saline solution. Another dosing scheme may be a dosing cycle of a saline solution and the dosing cycle of an additive solution.

[0059] FIG. 1 shows schematically an apparatus according to the invention. The apparatus comprises a dispenser block 2 and a dispenser head 3. The dispenser block 2 comprises a frame (not shown in FIG. 1) to which reservoir 20 is attached. Reservoir 20 has a reservoir wall 201 made of transparent polypropylene. Reservoir 20 is closed at its bottom and comprises an inlet cone 202 having a structure 203 for reducing the formation of foam during conveyance of the saline solution into reservoir 20. At the top of reservoir 20, a cover lid 204 closes the reservoir 20 in an air-tight manner. Cover lid 204 of reservoir 20 comprises an inlet pipe 28, a pressure compensation pipe 22 and a pump block.

[0060] The inlet pipe 28 further comprises a particle filter 27 having a pore size of 10 m and a bubble detector 29. The pressure compensation pipe 22 has a sterile filter 23 arranged therein to avoid the introduction of foreign matter into the reservoir 20 from the outside atmosphere.

[0061] The pump block comprises five dosing pumps 21 and a thick-walled tube 205 which extends into the liquid in the reservoir 20 and comprises an ascending pipe 206 in the inner volume of the thick-walled tube 205 and connected to the dosing pumps 21. The ascending pipe 206 has lateral openings arranged below the operational liquid level 26 for preventing any air bubbles to be conveyed to the dosing pumps 21 in the event air bubbles may reach the interior of the thick-walled tube 205. Air entrained in the liquid transported through the ascending pipe 206 would result in an incorrect volume of liquid being dispensed in to the cavities 1 of the packaging shells by the dispensing tips 30 of the dispenser head 3.

[0062] The dosing pumps 21 are of the type micro annular gear pump, and may for example be a micro annular gear pump of the type mzr-4665 M2.1, available from the company HNP Mikrosysteme GmbH, Schwerin, Germany. The apparatus comprising the dosing pumps 21 (micro annular gear pumps) may dispense volumes of 50 l to 1000 l with a tolerance of less than 5 l into each of the cavities 1 of the packaging shells. By way of example, a pre-dosing of 200 l saline solution may be performed before introducing the ophthalmic lens into the cavity 1, and a main dosing step of an additional 450 l of saline solution may then be performed to complete the immersion of the ophthalmic lens in the saline solution.

[0063] The dispenser block 2 further comprises a first liquid level sensor 24 which may be an optoelectronic sensor sensitive to water (e.g. a water molecular sensor of the type BOH TJ-R010-008-01-S49F, available from the company Balluff AG, Bellmund, Germany). This first liquid level sensor 24 is for determining the operational level 26 of the liquid in the reservoir 20. The dispenser block further comprises a second liquid level sensor 25 (the second liquid level sensor 25 is of the same type as the first liquid level sensor 24) arranged above the first water molecular sensor 24. This second liquid level sensor 25 is for determining a maximum liquid level in the reservoir 20.

[0064] The dispenser block 2 further comprises a storage container pump embodied as a peristaltic pump 5 which is mounted to a frame of the dispenser block 2 and which is directly driven by a servo motor controlled by the apparatus. Saline solution is transported from a saline bag 6 into the interior of the reservoir 20 through a saline tube 8 (reservoir inlet pipe) by the peristaltic pump 5.

[0065] The dispenser head 3 in this embodiment comprises five dispensing tips 30, a corresponding number of tip connectors 31, and a connector rail 33. The tip connectors 31 are fixedly attached to the connector rail 33 and the dispenser tips 30 are attached to the tip connectors 31.

[0066] The dispensing tips 30 and the tip connectors 31 both have corresponding fluid fittings of the type Luer lock for leakage-free, reliable and detachable connection of the dispenser tips 30 to the tip connectors 31.

[0067] The tip connectors 31 are connected to the dosing pumps 21 (micro annular gear pumps) via flexible tubes 4. The dispensing tips 30 have dispensing openings 34 at their end opposite to the Luer lock fitting.

[0068] When a dispensing tip 30 is clogged or otherwise mechanically damaged, it may be easily exchanged by removing the dispensing tip (having the Luer lock fitting) from the tip connector 31. The new dispensing tip 30 is attached to the tip connector 31 via the Luer lock fitting. Accordingly, the apparatus is quickly ready for operation again after exchange of the dispenser tip 30 and does not require extended purging in order to remove any air present in the system.

[0069] The first liquid level sensor 24 ensures a constant saline solution level in the reservoir 20 during operation of the apparatus and keeps the hydrostatic pressure of the saline solution in the reservoir 20 constant for reliably dispensing reproducible dosing volumes into the cavities 1 of the packaging shells. In case the peristaltic pump 5 conveys an excess amount of saline solution from the storage container 6 into the reservoir 20, the second liquid level sensor 25 avoids overflow of the reservoir 20 which may otherwise lead to saline solution wetting the sterile filter 23.

[0070] The dispensing openings 34 of the dispensing tips 30 are arranged at the same level as the predetermined operation level 26 of liquid in the reservoir 20 as determined by the first liquid level sensor 24. The hydrostatic pressure then tends to zero and reduces undesirable saline solution conveyance and prevents any spilling or retraction of the liquid to be dispensed (leading to dead volume in the dispensing tip), which could result in incorrect volume dispensing into the cavities 1 of the packaging shells.

[0071] The bubble sensor 29 arranged at or in the reservoir inlet pipe 28 detects any air bubbles which may be entrained in the saline solution pumped by the peristaltic pump 5 in the event of an saline bag 6 getting empty, and generates a warning signal to the system (controller) indicating an upcoming saline bag exchange requirement.

[0072] During operation, the peristaltic pump 5 conveys saline solution from the saline bag 6 through the saline tube 8 into the reservoir 20. The peristaltic pump 5 is controlled such as to maintain a predetermined operational liquid level 26 with the aid of the first liquid level sensor 24 with an accuracy of less than 0.5 mm (millimeters) above or below the operational liquid level 26. To avoid overflow of the reservoir 20 the second liquid level sensor 25 determines whether the maximum liquid level is reached in the reservoir 20, and if this is the case it stops the peristaltic pump 5 from pumping further saline solution into the reservoir 20. The reservoir inlet pipe 28 leading into the reservoir comprises a particle filter 27 through which the saline solution passes while being pumped into the reservoir 20. The sterile filter 23 in the pressure compensation pipe allows pressure variations to be compensated while preventing any foreign organic or inorganic matter to enter the reservoir 20 and the saline solution contained therein.

[0073] The saline solution is transported from the reservoir 20 through the ascending pipe 206 arranged in the thick-walled tube 205 to the dosing pumps 21 (micro annular gear pumps) when these dosing pumps 21 (micro annular gear pumps) are operated to dispense saline solution into the cavities 1 of the packaging shells. The saline solution is drawn into the ascending pipe 206 via laterally arranged openings in the wall of the ascending pipe 206 to avoid aspiration of air bubbles which may possibly be contained in the interior of the thick-walled tube 205.

[0074] The dosing pumps 21 convey the saline solution through the tubes 4 to the dispensing tips 30. The dispensing openings 34 of the dispensing tips 30 are arranged above the cavities 1 of the packaging shells to fill the cavities 1 with the desired amount of saline solution.

[0075] Once the desired amount of saline solution has been dispensed into the cavities 1, the controller of the apparatus may reverse the dosing pumps 21 (micro annular gear pumps) to make them retract a very small predetermined volume of saline solution from the dispensing tip 30 in order to avoid any spilling of saline solution onto the packaging shell 1.

[0076] The tip connectors 31 are fixedly arranged on the connector rail 33 and the dispensing tips 30 are connected to the corresponding tip connectors 31 via Luer Lock fittings 301, 311 (see FIG. 4) so that they may be easily exchanged in the event of one or more clogged dispensing tips 30, while maintaining the exact position of the respective dispensing tip opening 34 over the respective cavity 1 of the respective packaging shell.

[0077] FIG. 2 shows an embodiment of the apparatus according to the invention. The dispenser head 3 is separate from the dispenser block 2, and is arranged spaced apart from the dispenser block 2 above the packaging shells (which are transported along a transport path through the various stations of the production line or packaging line). Dispenser block 2 comprises a frame 7 to which reservoir 20 is mounted. The cover lid 204 of reservoir 20 is fixedly attached to the frame 7 whereas the body of reservoir 20 is attached to the cover lid 204 via a threaded connection formed between the upper portion of the reservoir wall 201 and the cover lid 204. The peristaltic pump 5 and its pump head 50 and drive 51 are arranged on the frame 7 of dispenser block 2. The dispenser head 3 is separate from the dispenser block 2 and comprises a connector rail 33 on which the tip connectors 31 are fixedly arranged to which the dispensing tips 30 are connected. The tip connectors 31 and thus the dispensing tips 30 are in fluid communication with the dosing pumps 21 (micro annular gear pumps) via the flexible tubes 4.

[0078] The first liquid level sensor 24 (e.g. water molecular sensor, as discussed above) and the second liquid level sensor 25 (also a water molecular sensor, see above) are fixedly attached to the frame 7 of the dispenser block 2 and hence their mounting level is invariable. In the event of removing the reservoir 20 for cleaning, for example, or if the reservoir 20 is replaced with another reservoir 20, no laborious adjustment of the liquid level sensors 24 and 25 is required.

[0079] FIG. 3 (an enlargement of detail A in FIG. 2) shows the integration of the peristaltic pump 5 in the frame 7 of dispenser block 2. The peristaltic pump 5 comprises a peristaltic pump head 50 and a peristaltic pump drive 51. The peristaltic pump drive 51 is directly linked to the dispenser controller and does not need any additional interface for being operated and controlled. This allows for a simple and efficient integration of the peristaltic pump 5 in the apparatus as well as for a more accurate saline solution conveyance.

[0080] FIG. 4 shows a Luer lock system used for the connection of the dispenser tips 30 to the tip connectors 31. Each dispenser tip 30 has a female Luer lock fitting 301 which is designed to cooperate with a male Luer lock fitting 311 of the tip connector 31. The fitting is detachable to allow for an easy and reliable exchange of the dispensing tip 30. The Luer lock is a standardized system of small-scale fluid fittings used for making leakage-free connections between a male-taper fitting and its mating female fitting in medical and laboratory instruments.

[0081] The apparatus according to the invention can be used in a fully automated ophthalmic lens production process, such as, for example, a (soft) contact lens or intraocular lens production process. The apparatus is simple in construction and is capable of very accurately and reproducibly dispensing small liquid volumes into the cavities of packaging shells.

[0082] While embodiments of the invention have been described with the aid of the drawings, various changes, modifications, and alternatives are conceivable without departing from the teaching underlying the invention. Therefore, the invention is not intended to be limited to the described embodiments but rather is defined by the scope of the appended claims.