Container for metered dispensing of a fluid

Abstract

The invention relates to a container for metered dispensing of a sterile fluid, the container comprising a substantially rotationally symmetrical storage body (12) made of plastics material, having a longitudinal axis (O) and a radial direction (R) extending perpendicularly to the longitudinal axis, wherein the storage body (12) comprises a substantially cylindrical or conical casing portion (14) having a first wall thickness (S1), a metering portion (16), a bottom portion (18) and a container neck portion (20), characterised in that the metering portion (16) is arranged between the casing portion (14) and the bottom portion (18), and is designed as a folding bellows having at least one radially inward fold having pivot points (36, 38, 40); wherein the wall thickness (S2) of the metering portion (16) is reduced, at least in the region of the pivot points (36, 38, 40), by 25% to 60% with respect to the first wall thickness S1.

Description

[0001] Container for the metered dispensing of a liquid

[0002] Field of the invention

[0003] The invention relates to a container for the metered dispensing of a sterile liquid.

[0004] Background of the invention

[0005] Sterile liquids, such as eye drops, are either offered in single-dose containers or dispensed from containers containing the amount of sterile liquid needed for multiple applications. Eye drops are instilled by the user into the conjunctival sac or onto the cornea and must be sterile to prevent eye infections.

[0006] When sterile liquids are to be dispensed in precisely prescribed doses in the form of a certain number of drops, containers have been proposed in the prior art with which a defined portion can be dispensed from the container. For this purpose, the storage container is provided, for example, with an elastic side wall that can be compressed by the user during use to dispense one or more individual drops. When dispensing eye drops, the container is usually turned upside down so that the dispensed drops essentially reach the user's eye from above.

[0007] Containers have also been proposed in the prior art whose base wall can assume two defined states. By applying pressure to the base, a container base which is curved in the first position towards the outside of the container can be transferred into a second position by applying pressure to the base wall, in which the base is curved towards the interior volume of the container. During the movement from the first position to the second position, a defined volume inside the container is displaced, whereby a defined amount of liquid can be dispensed from a dispensing opening.

[0008] Since the function of such a base, which can assume various geometric shapes, is not intuitively recognizable to the user, there is a need for a container for the metered dispensing of a sterile liquid whose operation is recognizable and deducible to the average user from its shape. At the same time, the container must be easy to manufacture, since such containers are mass-produced.

[0009] Description of the invention

[0010] This object is achieved by a container for the metered dispensing of a sterile liquid having the features of claim 1. Preferred embodiments follow from the remaining claims.

[0011] A container according to the invention for the metered dispensing of a sterile liquid comprises a substantially rotationally symmetrical storage body made of plastic with a longitudinal axis and a radial direction running perpendicular to the longitudinal axis, wherein the storage body comprises a substantially cylindrical or conical shell section with a first wall thickness, a metering section, a base section and a container neck section. The container is characterized in that the metering section is arranged between the shell section and the base section and is designed as a bellows with at least one fold radially inwards with articulation points, wherein the wall thickness of the metering section is reduced by 25% to 60% compared to the first wall thickness, at least in the region of the articulation points.

[0012] The container according to the invention thus has a dosing section which is arranged between the jacket section and the base section of the container and is clearly visible in the region of the jacket surface of the container. This dosing section is designed as a bellows, as a result of which the radially inward folding is clearly visible to a user. A user therefore also recognizes intuitively how the container according to the invention is to be used. The use is made possible by the fact that the wall thickness of the dosing section is provided with a reduced wall thickness, at least in the region of the articulation points of the at least one fold, the wall thickness being reduced by 25% to 60% compared to the wall thickness of the essentially cylindrical or conical jacket section, at least in the region of the articulation points.Due to the reduced wall thickness of the joints, the container produced in one piece can be folded together in the folding area, in that when pressure is applied to the base section, the height of the container is reduced because the height of the dosing section is reduced. The reduced wall thickness is preferably only provided in the area of ​​the joint points, as a result of which only a few points with a low wall thickness are formed, which can also be kept low in the dosing section with regard to the penetration of oxygen, for example, by diffusion through the container wall. This is advantageous because, particularly in the case of oxygen-sensitive products, the stability behavior would be reduced by a large-scale reduction in wall thickness. Since the dosing section is arranged between the jacket area and the base section, a label can be attached to the jacket section in the usual way.

[0013] Preferred embodiments follow from the remaining claims. According to a preferred embodiment, the base section has a concentrically arranged curvature in the direction of the dosing section. This curvature of the base section causes the user's thumb, which is often placed on the base to compress the dosing section, to automatically rest in the region of the center of the base section during use, thereby resulting in uniform compression of the dosing section around the circumference of the substantially rotationally symmetrical storage body of the container.

[0014] According to a preferred embodiment, the entire dosing section has a smaller wall thickness than the first wall thickness, and preferably the entire dosing section has a wall thickness that is reduced by 25% to 60% compared to the first wall thickness. If the entire dosing section has a smaller wall thickness than the first wall thickness, part of the movement of the bellows can occur through the articulation points, while another part of the movement of the bellows can also occur through a bending of the wall sections of the bellows between the articulation points. In this way, the articulation points are subjected to less mechanical stress.

[0015] The dosing section preferably has a single fold, comprising a first joint point on the jacket section, a second joint point on the base section, a first, annular joint leg which extends radially inwards from the first joint point and at a first angle relative to the radial direction, a second, annular joint leg which extends radially inwards from the second joint point and at a second angle relative to the radial direction, and a third joint point which connects the first joint leg to the second joint leg. It is preferred that the first joint leg and the second joint leg have a substantially rectilinear course in a sectional plane perpendicular to the longitudinal axis.

[0016] In this way, the dosing section is formed similarly to a disc spring, which is elastically compressible in the direction of the longitudinal axis when pressure is applied.

[0017] According to a preferred embodiment, the first, second and third joint points as well as the second joint leg have a smaller wall thickness than the first wall thickness, and the first joint leg has a greater wall thickness than the second joint leg.

[0018] In this way, the movement of the dosing section when pressure is applied to the base section occurs essentially in the area of ​​the second, annular joint leg near the base section.

[0019] According to a preferred embodiment, the first angle is smaller than the second angle.

[0020] This measure also serves to ensure that the deformation of the bellows during compression of the metering section takes place more strongly in the area of ​​the second joint point adjacent to the base section than in the area of ​​the first joint section adjacent to the jacket section.

[0021] It is preferred that the second angle is more than twice as large as the first angle, and preferably the second angle is between 30 ° and 40 °.

[0022] According to a preferred embodiment of the invention, the second articulation point is located at a shorter distance from the longitudinal axis than the first articulation point. This measure also results in the half of the bellows facing the base section, between the third articulation point and the second articulation point, performing a greater movement during compression than the upper half of the bellows, whereby, during compression, the metering section primarily moves in the region of the second articulation point.

[0023] Preferably, the ratio between the outer diameter of the base section and the inner diameter of the container in the region of the third joint point is approximately 2:1.

[0024] In this way, a sufficiently high folding is created in the area of ​​the bellows in the dosing section.

[0025] According to a preferred embodiment of the invention, the container further comprises an external thread on the container neck portion. This external thread serves for screwing on a closure cap, with the aid of which a dispensing opening located in the container neck portion can be closed for dispensing a sterile liquid.

[0026] It is further preferred that the container further comprises a shoulder portion between the jacket portion and the container neck portion.

[0027] Such a shoulder section can increase the ease of use of a small container, as is often used for storing and dispensing eye drops, in that the user can hold it at the shoulder section with the thumb of one hand and on the outside of the base section with a finger of that hand. With small containers, such as those with a capacity of 5 ml, the container can be held comfortably in this way and the pressure exerted on the base of the container when the dosing section is actuated is absorbed by a counter-bearing while simultaneously holding the shoulder section.

[0028] According to a preferred embodiment of the invention, the container further comprises a circumferential toothing provided on the container neck section, which comprises a plurality of substantially tangentially extending ramp surfaces and a plurality of substantially radially extending locking surfaces, each of which adjoins a ramp surface.

[0029] The toothing on the container neck section thus serves to screw a closure cap onto the storage body, which closure cap has a conventional tamper-evident ring which is connected to the closure cap via thin-walled bridge sections and which, after the container has been filled, can be screwed onto the storage body in one piece with the closure cap via the toothing, since the tamper-evident ring can be moved via the tangentially running ramp surfaces when it is screwed on for the first time.However, when opened for the first time, the tamper-evident ring detaches from the cap as it strikes the locking surfaces and is prevented from following the rotational movement of the cap when unscrewing, whereby the bridge sections are severed and the tamper-evident ring remains in the area of ​​the teeth, where it provides a clear visual indication to a user that the container has already been opened and the contents may no longer be sterile.

[0030] The container preferably has an associated closure cap that can be screwed onto the storage body and, when screwed on, seals the container hermetically. This is achieved by means of measures known in the art, such as the provision of an annular seal on the inside of the top side of the closure cap, which, after the closure cap has been screwed on, rests elastically against the outer circumference of a dispensing opening in the container neck section, thus sealing the container hermetically.

[0031] Short description of the drawings

[0032] The invention is illustrated below purely by way of example using an embodiment of the container according to the invention. Shown are:

[0033] Fig. 1 is a three-dimensional view of the container according to the invention;

[0034] Fig. 2 is a side view of the container according to Fig. 1;

[0035] Fig. 3 is a sectional view of the container according to Fig. 2 along the section line AA; and

[0036] Fig. 4 is a plan view of the container according to Fig. 1.

[0037] Ways of carrying out the invention

[0038] Figures 1 to 4 show an embodiment of the container 10 according to the invention for the metered dispensing of a sterile liquid. The container is preferably dimensioned such that a predetermined amount of sterile liquid is dispensed via the actuation of the bellows, as described below.

[0039] The container has a storage body 12 for the sterile liquid and a closure cap (not shown in the figures) which can be screwed onto the storage body. The storage body has a longitudinal axis O and is essentially rotationally symmetrical to the longitudinal axis O. The radial direction R shown as an example in Fig. 4 runs perpendicular to the longitudinal axis. The storage body 12 has a jacket section 14 which is essentially cylindrical in the present exemplary embodiment, but can equally well be conical and has a first wall thickness S 1. A dosing section 16 is integrally connected to the jacket section 14, and a base section 18 is in turn integrally connected to the dosing section 16. Furthermore, the storage body 12 has a container neck section 20 which includes a dispensing opening 22 for dispensing the sterile liquid.An external thread 24 is formed on the container neck portion 20, which serves to screw on a closure cap (not shown). A circumferential collar 26, also shown in the figures, serves to hold the storage body, particularly during filling with liquid during an industrial filling process.

[0040] The container according to the present embodiment is additionally provided with a tamper-evident device 28 which is provided between the external thread 24 and the jacket section 14 and serves to detach a tamper-evident ring, which is attached to the closure cap in the usual way via bridge webs, from the closure cap when the container is opened for the first time by unscrewing the closure cap and to make it visible to a user that the container has already been opened. The tamper-evident device 28 can be designed in any desired way. In the present case, a toothing 30 is provided which comprises a plurality of essentially tangentially oriented ramp sections 32 and locking sections 34 arranged essentially radially between these. As can be seen from the representation of the plan view in Fig.4, a closure cap can be screwed on for the first time in a clockwise direction together with the tamper-evident ring, since the latter is moved along with the closure cap via the ramp sections 32 in accordance with the effect of a ratchet, whereas when the closure cap is opened for the first time the tamper-evident ring is prevented from moving counterclockwise in Fig. 4 by the locking sections 34, as a result of which the web-shaped bridge sections between the closure cap and the tamper-evident ring tear and the tamper-evident ring remains above the toothing after the closure cap has been unscrewed, whilst the closure cap can be unscrewed. The tamper-evident device used in the embodiment shown can, however, be replaced in the same way within the scope of the invention by another tamper-evident device known in the art.

[0041] The dimension of the dispensing opening 22 and in particular its diameter is preferably adapted to the drop size of sterile liquid formed and can have an opening diameter of between 8.1 mm and 8.3 mm for water-based liquids.

[0042] The dosing section 16 arranged between the jacket section 14 and the base section 18 is located at a position where it does not conflict with the attachment of a label to the jacket section 14 and is thus clearly recognizable by a user. The dosing section 16 is designed as a bellows and can have one or more folds. In the present embodiment, a single fold is provided. For this purpose, the dosing section 16 has a first hinge point 36, a second hinge point 38 and a third hinge point 40. The first hinge point 36 represents the transition between the jacket section 14 and the dosing section 16. The second hinge point 38 represents the transition between the base section 18 and the dosing section 16. The third hinge point 40 is provided within the fold.

[0043] In addition, a first joint leg 42 is provided, which connects the first joint point 36 to the third joint point 40. A second joint leg 44 connects the third joint point 40 to the second joint point 38. In the present exemplary embodiment, the joint legs 42 and 44 are ring-shaped and have a substantially rectilinear course in the sectional plane shown in Fig. 3, perpendicular to the longitudinal axis (0).

[0044] The wall thickness (S2) of the metering section is reduced by 25% to 60% compared to the first wall thickness (S1). However, it is also possible to design the first joint leg 42 and the second joint leg 44 with the same wall thickness S1 as the shell section and to provide a correspondingly reduced wall thickness only in the region of the joint points 36, 38, 40 in order to enable increased deformation of the metering section 16 in these regions.

[0045] As can also be seen in Fig. 3, angles of different sizes are formed, in which on the one hand the first joint leg 42 runs relative to the radial direction R, and in which on the other hand the second joint leg 44 runs relative to the radial direction R. In the specific exemplary embodiment, the angle ß between the second joint leg 44 and the radial direction is more than twice as large as the angle α between the first joint leg 42 and the radial direction. In the specific example, the angle α could be between 10 ° and 15 °, while the angle β could be between 30 ° and 40 °. The different angles serve to ensure that when the dosing section 16 is actuated by external pressure on the base section, as described later, the movement takes place primarily in the area of ​​the second joint point 38 and the second joint leg 44.In the same way, according to an alternative embodiment, it is also possible to modify the design according to Fig. 3 so that the actuation takes place essentially uniformly via the first joint leg and the second joint leg, or the actuation takes place essentially only via the first joint leg.

[0046] Furthermore, it has proven advantageous if the inner diameter Di of the container in the region of the third articulation point 40 is selected such that it is approximately half as large as the outer diameter Da of the base section 18 in the region of the second articulation point 38.

[0047] It is also advantageous if the second joint point 38 is located at a smaller radial distance from the longitudinal axis 0 than the first joint point 36 between the jacket section 14 and the dosing section 16. It follows from this that the radius of the base section 18 is smaller than the radius of the jacket section 14. This geometry, together with the ratio between the dimensions Da:Di, has proven particularly advantageous with regard to the best possible force transmission and force introduction. The force is introduced via the base 18 in the direction of arrow B. Due to the cylindrically symmetrical shape of the base 18 and a curvature 46 of the base in the direction of the internal volume of the container, the force is transmitted essentially concentrically. The curvature 46 is advantageous because the user automatically presses towards the deepest point of the curvature 46 when actuating the device, and the concentricity of the force introduction is therefore improved.However, the lever arm is also crucial for the necessary application of force. If the lever arm is too small, the system will be stiffened and the actuation force will be higher. However, if the lever length is too long, depending on the wall thickness selected, the dosing section will be too soft and insufficient force will be introduced into the dosing section, which is in the form of a disc spring, to actuate it. This would result in the excess pressure required to form a drop being too low and no drop would emerge from the dispensing opening 22 which serves as the drip hole. For this reason, the lever arm selected, with a ratio of 2:1 between the outer base diameter Da and the inner pleat diameter Di, has proven to be very suitable for achieving optimal application of force to form a drop.

[0048] However, the radius of the base section can also correspond to the radius of the shell section according to an alternative design.

[0049] The bottom section 18 itself also has a certain flexibility, so that even with sufficient pressure applied to the bottom, a drop can be released if only the bottom of the bottle is compressed.

[0050] Due to the design of the dosing section 16, the container according to the invention can also be made of stiffer plastic materials such as HDPE and PP, which are sometimes used for reasons of resistance to sterile liquids.

[0051] It is crucial that at least the joints have a reduced wall thickness for the suspension function. It can even be advantageous to provide only the joints with a thinner wall thickness, as this reduces the diffusion of oxygen through the outer wall of the container and thus results in better stability for oxygen-sensitive products. The shape makes it intuitive for the user how to operate the container. If a user presses on the middle of the base section 18 in order to compress the dosing section 16, it has proven advantageous to provide a shoulder section 48 between the jacket section 14 and the container neck section 20, which shoulder section acts as a counter-bearing to facilitate the application of force to the base section.The storage body 12 of the container according to the invention can be manufactured in one piece from plastic, making the container well suited for mass production. By selecting the wall thicknesses in the dosing section, the angle between the first joint leg and the radial direction, the angle between the second joint leg and the radial direction, and the ratio between the outer base diameter Da and the inner pleat diameter Di, an approximately constant actuating force can always be set for the user, independent of the container volume, the other wall thickness of the container, and also of the selected plastic material.

Claims

Claims: Container for the metered dispensing of a sterile liquid, comprising a substantially rotationally symmetrical storage body (12) made of plastic with a longitudinal axis (0) and a radial direction (R) perpendicular to the longitudinal axis, wherein the storage body (12) comprises a substantially cylindrical or conical shell section (14) with a first wall thickness (Sl), a metering section (16), a bottom section (18), and a container neck section (20), characterized in that the metering section (16) is arranged between the shell section (14) and the bottom section (18), and is designed as a bellows with at least one radial inward fold with hinge points (36, 38, 40); wherein the wall thickness (S2) of the metering section (16) is reduced by 25% to 60% compared to the first wall thickness Sl, at least in the region of the hinge points (36, 38, 40). Container according to claim 1, characterized in that the bottom section (18) has a concentrically arranged bulge (46) in the direction of the metering section (16). Container according to claim 1 or claim 2, characterized in that the entire metering section (16) has a smaller wall thickness (S2) than the first wall thickness (Sl), preferably the entire metering section (16) has a wall thickness that is reduced by 25% to 60% compared to the first wall thickness (Sl).Container according to one of claims 1 to 3, characterized in that the metering section (16) has a single fold comprising a first hinge point (36) on the shell section (14), a second hinge point (38) on the bottom section (18), a first annular hinge leg (42) extending radially inwards from the first hinge point (36) and at a first angle (a) relative to the radial direction (R), a second annular hinge leg (44) extending radially inwards from the second hinge point (38) and at a second angle (β) relative to the radial direction (R), and a third hinge point (40) connecting the first hinge leg (42) to the second hinge leg (44). Container according to claim 4, characterized in that the first, second, and third joint points (36, 38, 40) and the second joint leg (44) have a smaller wall thickness than the first wall thickness (Sl), and the first joint leg (42) has a larger wall thickness than the second joint leg (44). Container according to claim 4 or claim 5, characterized in that the first joint leg (42) and the second joint leg (44) have a substantially straight course in a section plane perpendicular to the longitudinal axis (0). Container according to claim 6, characterized in that the first angle (a) is smaller than the second angle (β). Container according to claim 7, characterized in that the second angle (β) is more than twice as large as the first angle (a), and preferably the second angle (β) is between 30° and 40°.Container according to any one of claims 4 to 8, characterized in that the second hinge point (38) is located at a smaller radial distance to the longitudinal axis (0) than the first hinge point (36). Container according to any one of claims 4 to 9, characterized in that the ratio between the outer diameter (Da) of the bottom section (18) to the inner diameter (Di) of the... The ratio of the container in the area of ​​the third hinge point (40) corresponds approximately to 2:

1. A container according to one of the preceding claims, further comprising an external thread (24) on the container neck section (20). A container according to one of the preceding claims, further comprising a shoulder section (48) between the shell section (14) and the container neck section (20). A container according to one of the preceding claims, further comprising a circumferential toothing (30) provided on the container neck section (20), comprising a plurality of substantially tangentially extending ramp surfaces (32) and a plurality of substantially radially extending locking surfaces (34), each adjoining a ramp surface (32). A container according to one of the preceding claims, further comprising an associated closure cap that can be screwed onto the storage body (12) and, when screwed on, tightly seals the container.

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