Liquid dispenser and protective cap for liquid dispenser

Abstract

It is proposed a liquid dispenser (10) for dispensing, in particular, a medical liquid by means of a discharge opening (16) protected by a protective cap (50), the protective cap (50) having a fixed part (60) adapted to be coupled to the housing (14) of the liquid dispenser (10) and an inner part (80) separated from the fixed part (60) and surrounding the discharge opening (16) in the fitted state of the protective cap. The inner part (80) is non-detachably coupled to the fixed part (60) by coupling devices (66, 86), the inner part being freely rotatable relative to the fixed part (60) around the longitudinal axis (2) of the protective cap (50).

Description

[Technical field]

[0001] The present invention relates to liquid dispensers, and in particular to protective caps therefor. [Background technology]

[0002] A common type of liquid dispenser has a liquid reservoir, which is filled with, in particular, a medicinal liquid, and is used to dispense the liquid through a discharge opening, for example in the form of droplets that are applied to a patient's eye.

[0003] To protect the discharge opening, a common type of liquid dispenser comprises a protective cap which is fitted onto the housing of the liquid dispenser when not in use. The protective cap protects the discharge opening against external mechanical influences. It may in particular be performed with the addition of further functions such as venting the discharge opening or absorbing residual liquid at the discharge opening.

[0004] In the mated state, a typical protective cap rests sealingly against the housing of the liquid dispenser: if the protective cap is removed, this sealing point is interrupted, but the relative movement of the protective cap and the housing is made difficult by the friction that prevails at the sealing point, where wear occurs, which impairs the sealing action when the protective cap is re-fitted.

[0005] US2015 / 0043958A1 discloses a protective cap having an inner cap and an outer cap. In the mated state, the inner cap surrounds the discharge opening and is fixed on the housing of the liquid dispenser by a screw connection. The outer cap can initially move relative to the inner cap, in particular both in a rotational and linear movement. This relative movement opens a passage through which residual liquid can escape from the discharge opening when the caps are mated.

[0006] EP 3119529 B1 discloses a protective cap with an absorbing buffer, which is inserted into a ring body to facilitate mounting on the protective cap. Summary of the Invention

[0007] The problem addressed by the present invention is to provide a liquid reservoir and its protective cap which allows for a satisfactory liquid seal even with repeated use, yet still allows for easy removal of the protective cap.

[0008] For this purpose, the invention proposes a liquid dispenser comprising in a known manner a liquid reservoir in which the liquid is stored before being discharged. Depending on the intended application, said liquid reservoir has a volume of less than 200 mL, in particular less than 50 mL. The liquid dispenser further comprises a housing and a discharge opening through which the liquid can be discharged into the environment. The discharge opening is provided either directly through the housing or on an actuation push button movable relative to the housing. A pump device is preferably provided for the transport of the liquid from the liquid reservoir to the discharge opening. Said pump device can be actuated by the aforementioned actuation push button. However, it is particularly advantageous if an actuation push button separate from the discharge opening is provided for actuating the pump device, particularly preferably on a lateral shell surface of the housing.

[0009] The liquid dispenser is preferably configured for the discharge of medicinal liquids. Correspondingly, in the delivery state, the liquid reservoir is preferably filled with such liquid. However, other fields of application are also encompassed, in particular cosmetic liquids, technical liquids and food products.

[0010] In particular, the design of the liquid dispenser according to the invention is configured for dispensing droplets. In the case of such a droplet dispenser, the discharge opening is assigned a droplet forming contour downstream of the discharge opening, where liquid accumulates in order to be released in the form of droplets, for example for application in the eye. There is a risk of contamination of the residual liquid, especially in the case of medicinal liquids that are dispensed in droplet form and accumulate on the outer surface of the dispenser during intended use.

[0011] The liquid dispenser according to the invention comprises a protective cap according to the invention which, in the fitted state, protects the discharge opening and is removable for the purpose of dispensing liquid, in particular for this purpose by unscrewing it from the housing.

[0012] The protective cap comprises at least two components, in particular a fixed part and an inner part.

[0013] The fastening part is configured for coupling to a housing of a liquid dispenser, the main function of the fastening part therefore being to mechanically couple the protective cap to the housing, e.g. by means of threads in case of a screw cap or by means of a clamping area in case of a push-on cap, said clamping area forming a frictionally holding clamping connection against the outer contour of the housing.

[0014] The protective cap further comprises the above-mentioned inner part separated from the fixed part, in the fitted state of the protective cap, said inner part surrounds the discharge opening, so that together with the surface surrounding the discharge opening it forms a discharge opening space and seals said discharge opening space against the actuation push button or the housing of the liquid dispenser.

[0015] The inner part is non-releasably coupled to the fixed part by a coupling device, said inner part being freely rotatable relative to the fixed part about the longitudinal axis of the protective cap.

[0016] Designing a cap with a fixed part and an inner part that are attached to one another so as to be rotatable relative to one another about a longitudinal axis leads to a number of advantages. In particular, it results in a decoupling that is advantageous for the sealing point formed by the inner part. When unscrewing a protective cap, for example in the form of a screw cap, the fixed part is already displaced and rotated, while the inner part continues to rest against the housing, at least initially, in a rotationally fixed manner. This avoids wear of the sealing point.

[0017] Furthermore, removal of the cap is also simplified, since it is no longer necessary to directly apply a force or torque to overcome friction at the sealing point. Instead, in the case of a screw cap, only the fixed part is rotated first. Only after said fixed part has been displaced axially over a distance relative to the housing does the resulting tensile force act indirectly on the inner part with sufficient strength to pull the inner part away from the housing. The expenditure of force required to release the screw or plug-on connection between the housing and the fixed part is separated in time from the expenditure of force required to release the inner part from the housing.

[0018] The advantage of the separate design of the inner part and the fixed part is also the possibility of using different materials. It is therefore possible to use materials that are well adapted to the main function in each case. The material selection for the fixed part can be carried out especially with regard to the fixing function. Preferably, a relatively hard plastic with a low friction surface is advantageous for the thread. A relatively soft material is advantageous for the main function of the inner part and its sealing with the housing.

[0019] A further advantage of the separate configuration of the inner part and the fixed part is given when the inner part is tiltable, at least to a limited extent, with respect to the fixed part, which is achieved in that even if the plugging-on or screwing of the fixed part is performed in a slightly tilted orientation, this does not result in a similarly tilted fit of the inner part and therefore a compromised sealing effect. Rather, by virtue of a conically or otherwise widening shape, particularly at the open end to correspond to the housing, the inner part can be independently oriented in a manner separate from the fixed part and an ideal sealing effect can be obtained.

[0020] The risk of mechanical loading of the fixing part forming the outer sleeve compromising the sealing action at the sealing point between the housing and the protective cap is also reduced: mechanical influences on the fixing part cause a relative displacement to the inner part rather than the sealing point between the inner part and the housing of the liquid dispenser being opened unintentionally.

[0021] Preferably, the mobility of the inner part relative to the fixed part is not limited to a rotational mobility, and possibly a tilting mobility, but may in particular be provided with an axial mobility. Particularly preferably, the inner part is axially movable by at least 0.5 mm, preferably by at least 1 mm, between two end positions relative to the fixed part. This has the effect that when pulling the protective cap apart or rotating it loose, the sealing point is only released after the fixed part has already been axially displaced by a corresponding distance relative to the housing.

[0022] In order to receive the inner part and to obtain movability between the inner part and the fixed part, the fixed part preferably defines a receiving space in which the inner part is non-detachably arranged. This receiving space is preferably terminated by an inwardly facing retaining edge provided towards the open end of the fixed part, i.e. in the direction of the actual dispenser or its liquid reservoir, in particular on a circumferentially inwardly facing web. The retaining edge has a net cross section smaller than the outer diameter of the inner part, so that during mounting the inner part is pressed onto it, in particular by a lead-in bevel provided on the retaining edge, and then latched into the receiving space. Contrary to the retaining edge, the receiving space is preferably defined by an end wall of the fixed part.

[0023] Preferably, the retaining edge on the fixed part is in the form of a circumferential retaining edge of uniform inner diameter, however, the retaining edge on the fixed part may also be formed by a plurality of retaining edge portions arranged in a circumferentially offset manner.

[0024] Furthermore, it is preferred that a retaining edge is provided on the inner part which cooperates with the retaining edge on the fixed part and which particularly preferably defines a uniform contour in the circumferential direction. Particularly preferably, the retaining edge of the inner part is provided on an outwardly projecting circumferential web.

[0025] Preferably, the protective cap has an air passage, through which the discharge opening is connected to the atmosphere surrounding the liquid dispenser when the protective cap is fitted. This means that even when the protective cap is fitted, air can enter the discharge opening space, facilitating the rapid drying of residual liquid at the discharge opening.

[0026] The ventilation channel is preferably realized by the fixed part and the inner part each comprising at least one opening. The ventilation channel extends through these two openings. Preferably, the openings are provided in each case on the end faces of the inner part and the fixed part.

[0027] The protective cap can preferably have a sterile filter arranged in the air passage. Said sterile filter is provided in the region of the opening in the fixed part and can filter the air flowing through said opening. However, particularly preferably, the sterile filter is provided in the opening in the inner part and spans said opening. When the protective cap is fitted, the discharge opening chamber is connected to the environment exclusively through the sterile filter.

[0028] In the context of the present invention, the sterile filter is a filter in the form of a depth filter or preferably in the form of a membrane filter, which has a separation limit suitable for removing at least 99.9% of all bacteria from the incoming ambient air. Preferably, the sterile filter has a separation limit of 0.3 μm or less, particularly preferably 0.2 μm or less. The sterile filter allows in particular the liquid dispenser to be shipped with an open airway. However, it may be advantageous for the airway to be closed in the shipping state, for example by an adhesive label that stretches over the opening.

[0029] Preferably, as an alternative to the sterile filter or in particular in addition to the sterile filter, the protective cap comprises an absorbent pad, which is provided on the inner part and which is arranged in the discharge opening space so as to abut against the discharge opening when the protective cap is fitted in order to absorb the liquid remaining therein after the discharge operation. The absorbent pad can also be arranged at a small distance from the discharge opening, as long as it reaches close by, in order to be able to absorb residual liquid drops from the discharge opening or from the surrounding discharge contour.

[0030] The absorbent pad is preferably made of a fibrous or porous material. It can be in a rigid or elastically deformable form. In particular, the material of the absorbent pad can exhibit hydrophilic properties in order to rapidly absorb the liquid and thus be able to remove it from the discharge opening.

[0031] Particularly preferably, the sterile filter and the absorbent pad are formed as two layers of the same layer complex, which can be indirectly or directly connected to one another by a common fastening on the inner part.

[0032] This layer composite or absorbent pad or sterile filter is fixed in the inner part or possibly to the fixed part, preferably by overmolding. In particular, the fixed part, the absorbent pad or the layer composite is engaged around on both sides by holding components in an integral manner. Overmolding creates a particularly tight and intimate connection between the plastic of the fixed part or inner part and the periphery of the sterile filter or absorbent pad.

[0033] The fixed part and the inner part each preferably comprise a side and an end wall. An opening is preferably provided in each of these end walls, since this simplifies manufacture. The openings are preferably aligned with each other, which is advantageously such that the narrowest diameter or narrowest net width of the openings in the fixed part is a maximum of 5 mm. This prevents the sterile filter provided in the opening of the inner part from being inadvertently damaged from the outside.

[0034] As already mentioned above, the protective cap is preferably in the form of a screw cap. It is therefore provided with a thread, in particular an internal thread, which is provided on the fixed part. A counter-thread, preferably an external thread, is provided on the outside of the housing of the liquid dispenser.

[0035] However, other designs of the protective cap are also conceivable, including in particular plug-on caps which do not need to be rotated for fitting and removal purposes, but rather can be pulled off or fitted without any rotational movement. In the case of such plug-on caps, the fixing part is configured to form a clamping connection with the housing. For the purpose of obtaining a clamping connection, the outer diameter of the housing and the clamping area of ​​the plug-on cap are adapted to each other. Since the fixing part does not need to perform any function with regard to sealing the cap, the inner clamping area can be designed in particular with elongated ribs, so that a good clamping action and an easy pull-off operation can be achieved at the same time. [Brief description of the drawings]

[0036] Further advantages and aspects of the present invention will become apparent from the following description of preferred exemplary embodiments thereof, as set forth below with reference to the drawings, and from the claims.

[0037] [Figure 1] FIG. 1 shows a cross-sectional view of a liquid dispenser according to the present invention.

[0038] [Diagram 2] FIG. 2 shows a cross-sectional view of the protective cap of the liquid dispenser according to FIG.

[0039] [Diagram 3] FIG. 3 shows a cross-sectional view of a second variant of a protective cap according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] 1 and 2 show a liquid dispenser and its protective cap according to the present invention.

[0041] In the present case, the liquid dispenser 10 is in the form of a droplet dispenser. It comprises a liquid reservoir 12, a pumping device 20 and a discharge opening 16, which are surrounded by a droplet-forming surface 18. As a droplet dispenser, the liquid dispenser 10 is used for its intended purpose in an overhead position with the discharge opening 16 facing downwards. In this position, the user presses the actuation button 22, whereby liquid is conveyed by the pumping device 20 from the liquid reservoir 12 in the direction of the discharge opening 16. Upstream of the discharge opening 16 is a discharge valve 24, which in the event of sufficient pressure opens and allows the liquid to escape onto the droplet-forming surface 18.

[0042] To protect in particular the discharge opening 16, but also the actuation button 22, a protective cap 50 is provided, which is shown separately in enlarged form in Figure 2. The protective cap 50 has two main components, in particular a fixed part 60 and an inner part 80.

[0043] The fixed portion 60 includes a side wall 60A and an end wall 60B. The female threads 52 are provided at the lower end of the side wall 60A in the perspective view of Figure 2 because the protective cap 50 is in the form of a screw cap. Correspondingly, male threads are provided on the exterior of the housing 14 of the fluid dispenser 10.

[0044] Furthermore, a ring-shaped tamper-evident portion 70 is provided at the lower end of said protective cap 50 and is connected to the side wall 60A by a thin plastic bridge. The end wall 60B is pierced by an opening 62. On the inside, the protective cap 50 comprises a circumferential retaining web having a retaining edge 66 which defines below a receiving space 64 for the fixed part 60.

[0045] The already mentioned inner part 80 is arranged in the receiving space 64. Said inner part also comprises a side wall 80A and an end wall 80B. An outwardly facing retaining web with a retaining edge 86 fixes the inner part 80 relative to the fixed part 60. However, the receiving space 64 is dimensioned such that the inner part 80 is movable therein, in particular rotatable relative to the fixed part 60, in particular about the longitudinal axis 2.

[0046] Like end wall 60B, end wall 80B is provided with an opening 82 through which spans a composite layer made up of sterile filter 56 and absorbent pad 54. This composite layer is overmolded in its peripheral area by the plastic material of inner portion 80.

[0047] In addition to being rotationally movable, the inner portion 80 is also axially displaceable relative to the fixed portion 60 in the direction of the longitudinal axis 2, preferably by about 0.5-1 mm.

[0048] If protective cap 50 is fitted in the manner shown in FIG. 1, the inner side 88 of side wall 80A forms a seal with the slightly tapered sealing surface 14A of housing 14 to prevent gas exchange thereat.

[0049] Ingress of air into the receiving space 64 and into the outlet opening space 84 defined by the internal body is still possible along the air passage 4 through the openings 62, 82, the air entering therein having been removed of bacteria by the sterile filter 56.

[0050] The two-part construction of the protective cap allows to obtain a good seal at the sealing points 88, 14A. If the screw cap 50 is rotated and loosened, no circumferential frictional relative movement between the sealing surfaces 88, 14A occurs. Instead, only the fixed part 80 is rotated. Only after said fixed part has been axially displaced to some extent due to the threads 52, the inner part 80 is pulled away from the housing 14.

[0051] 3 shows an alternative design of the protective cap 50. It is in the form of a plug-on cap. Correspondingly, instead of the threads 52 it comprises a rib, the inner surface of which forms a clamping surface 53.

Claims

1. A liquid dispenser (10), in particular for the delivery of medicinal liquids, comprising: (a) a liquid dispenser (10) comprising a liquid reservoir (12) in which liquid is stored prior to dispensing; (b) a liquid dispenser (10) comprising a housing (14) and a discharge opening (16) through which a liquid can be dispensed into an environment; (c) the liquid dispenser (10) includes a protective cap (50), which in the engaged state protects the dispensing opening (16), the protective cap (50) being removable for the purpose of dispensing the liquid; (d) the protective cap (50) includes a fastening portion (60), the fastening portion (60) configured to couple to the housing (14) of the fluid dispenser (10); (e) the protective cap (50) includes an inner portion (80), the inner portion (80) being separated from the fixed portion (60), the inner portion (80) surrounding the discharge opening (16) in the fitted state of the protective cap (50); (f) the inner part (80) is non-releasably coupled to the fixed part (60) by a coupling device (66, 86), said inner part being freely rotatable relative to the fixed part (60) about the longitudinal axis (2) of the protective cap (50); (g) the protective cap (50) has an air passage (4) through which the discharge opening (16) is connected to the atmosphere surrounding the liquid dispenser (10) when the protective cap (50) is fitted; (h) the fixed portion (60) and the inner portion (80) each include at least one opening (62, 82) through which the air passage (4) extends; A liquid dispenser (10) comprising:

2. The protective cap (50) has a sterile filter (56), the sterile filter (56) is disposed in the air passage (4), and the sterile filter (56) spans either an opening (62) in the fixed part (60) or an opening (82) in the inner part (80). The liquid dispenser (10) of claim 1.

3. The protective cap (50) has an absorbent pad (54) provided on the inner portion (80), the absorbent pad (54) abutting against or positioned immediately adjacent to the discharge opening (16) when the protective cap (50) is fitted. The liquid dispenser (10) of claim 1.

4. The opening (62) in the fixed portion (60) is formed in alignment with the sterile filter (56) and / or the absorbent pad (54). A liquid dispenser (10) according to claim 2 or 3.

5. The liquid dispenser (10) of claim 1 further comprising the following features: The protective cap (50) is in the form of a screw cap (50) whose internal threads (52) are disposed on the fixed part (60).

6. The inner part (80) is fixed to the fixed part (60) in an axially movable manner. The liquid dispenser (10) of claim 1.

7. The fixed part (60) includes a receiving space (64) in which the inner part (80) is non-detachably disposed, the receiving space (64) being terminated at an open end of the fixed part by a retaining edge (66) defining a net cross section smaller than the outer diameter of the inner part (80). The liquid dispenser (10) of claim 1.

8. The inner part (80) and the fixed part (60) are made of different materials. The liquid dispenser (10) of claim 1.

9. The material of the inner part (80) is softer than the material of the fixed part (60); The liquid dispenser (10) of claim 1.

10. The liquid reservoir (12) is filled with a medicinal liquid. The liquid dispenser (10) of claim 1.

11. A protective cap for a liquid dispenser (10) according to claim 1, comprising the following features: (a) a protective cap (50) including a fastening portion (60) configured to couple to a housing (14) of a liquid dispenser (10); (b) the protective cap (50) includes an inner portion (80), the inner portion (80) being separated from the fixed portion (60), the inner portion (80) surrounding the discharge opening (16) in the fitted state of the protective cap (50); (c) an inner part (80) is coupled to the fixed part (60) by a coupling device (66, 86) such that said inner part is freely rotatable relative to said fixed part about the longitudinal axis (2) of the protective cap (50); (d) the protective cap (50) has an air passage (4) through which the discharge opening (16) is connected to the atmosphere surrounding the liquid dispenser (10) when the protective cap (50) is fitted; (e) the fixed portion (60) and the inner portion (80) each include at least one opening (62, 82) through which the air passage (4) extends;

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