Valve for the application of drops

A valve (20) comprises a housing body (22) with a discharge channel (34), whereby an elastically-deformable membrane (24) is provided in the housing body which seals off the discharge channel. The membrane is sealed at the front end thereof and is arched to form a dome.

BACKGROUND OF THE INVENTION

The invention relates to a valve for the application of liquid health care products or of health care products dissolved in liquids, in particular of eye drops.

Dropper systems for drop application are known as components of medication packagings in a variety of embodiments. It is disadvantageous with the hitherto known dropper systems that, after a first use, contamination of the liquid to be applied cannot be effectively prevented since, when the screw cap has been removed, germs can enter into the health care product supply through the discharge passage. For this reason, preservatives have hitherto been added to the health care product which are intended to prevent the contamination of the health care product over a limited discharge period. Such preservatives can, however, cause allergic reactions in the user such that it is desirable to omit such additives.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a simple valve for the application of a health care product which also effectively prevents contamination of the liquid medication after a first use.

The possibility is provided with the valve in accordance with the invention to discharge the liquid to be applied through a sealed passage. The valve in accordance with the invention simultaneously consists of only two functional components, namely the take-up body and the membrane.

To prevent the access of micro-organisms into the medication supply, the discharge passage, and also an optional aeration passage, can be closed impermeable to germs with the help of the elastically deformable membrane. The discharge passage is only opened by the membrane at the moment of the product removal and the discharge passage is closed impermeable to germs again subsequent to the product removal.

In the event that the product quantity propelled out on the removal should be replaced by ambient air in order to avoid underpressure in the container, this air can be subsequently guided in through an aeration passage likewise closed by the elastic membrane. In this process, contamination of the container content is particularly effectively prevented if a sterile filter is provided in front of the orifice of the aeration passage in the take-up body so that the ambient air must first pass through the sterile filter before it can subsequently flow into the container.

In accordance with an advantageous embodiment, the front end of the membrane projects out of the take-up body such that the front end of the membrane can be used simultaneously as an elastic, and thus soft, application tip.

It is also advantageous for the membrane to be closed and/or arched in dome-shape at its front end. In this manner, a drop release is promoted and injuries in the region of the application area, in particular eye injuries, are precluded.

In accordance with a further advantageous embodiment, the membrane and the take-up body contact one another in a sealing manner along a contact section, with the contact section in particular being able to be made as a paraboloid of revolution. Such a shape has proved to be advantageous with respect to a safe opening and closing in the region of the contact section.

The membrane is preferably made as a hollow element open at one end such that good elasticity and thus good closing and sealing properties are ensured with a low material effort.

In accordance with a further advantageous embodiment, the membrane is rotationally symmetrical, and a support element which pre-stresses the membrane in the axial direction is arranged in the interior of the membrane. Such a support element can contribute to sealingly pressing the membrane against the contact section of the take-up body, with a release of the membrane from the take-up body nevertheless taking place against the pre-stressing force on application of the discharge pressure.

An embodiment which can be manufactured particularly easily and so cost-favorably is provided when the valve only consists of three functional components, namely the take-up body, the membrane and the support element. The only components which are still required, apart from the container, are a covering cap and an optional sterile filter. These components are, however, not components of the valve necessary for the function.

In a further advantageous embodiment of the invention, a plurality of ring passages are provided in the valve and communicate with one another via overflow passages. For example, a first ring passage can be provided between the support element and the membrane, and a second ring passage can be provided between the take-up body and the membrane, with the ring passages communicating with one another via an overflow passage in the membrane. In this embodiment, the liquid to be discharged is first transported into a ring space between the support element and the membrane and is subsequently transported into a ring space between the membrane and the take-up body. When the discharge pressure is increased, the liquid can then be transported from the second ring passage through the contact section in the direction of an outflow passage at the front end of the membrane or of the take-up body.

A particularly easy assembly of the valve is provided when the support element in the interior of the membrane is in engagement with the membrane via a latching means, for example via a peripheral latching lip. In this manner, the membrane only has to be pulled over the support element and latched, whereby these two components are already joined together. A simple assembly of this component pre-assembled in this manner can take place in that the support element is inserted into the take-up body with the membrane placed on and is secured in the take-up body via a further latching means. A fully functional valve is hereby provided with only two assembly steps.

The support element preferably extends at its rear end over the total internal cross-section of the take-up body, with a throughflow opening being able to be provided for the liquid to be discharged in this region. A secure holding of the support element and of the membrane is ensured in this manner.

The valve in accordance with the invention is also suitable for a container which is elastically deformable at least regionally, for example for a squeezy bottle. However, the possibility generally also exists of using the valve for rigid containers. In this case, the propelling-out pressure must be produced in another manner.

The present invention will be described in the following purely by way of example with reference to an advantageous embodiment and to the enclosed drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1shows, in cross-section, a container10in the form of a squeezy bottle in whose bottle neck a valve20is sealingly inserted via a pressing connection12. The valve20consists of three functional components, namely of a take-up body22, of an elastically deformable membrane24and of a support element26.

FIG. 2shows an enlarged cross-sectional view of the valve20. As can be recognized, the take-up body22is rotationally symmetrical and consists of a one-piece plastic component which tapers conically in the upper third. A ring-shaped projection26is shaped approximately in the middle of the take-up body22, with a ring-shaped groove, into which a sterile filter28has been inserted, being provided in the projection26. The sterile filter is in communication with the ambient air at its lower end face30, at the one end. At the other end, the air flowing through the sterile filter28can enter into the interior of the intake body22via an aeration passage32. Furthermore, a ring-shaped indentation38is provided in the region of the aeration passage32at the inner periphery of the take-up body22.

The take-up body22is hollow at its interior and, starting from its lower end, has a hollow cylindrical section which tapers in the upper third in accordance with the outer contour of the take-up body. A discharge passage34, through which the liquid to be applied can be discharged, is furthermore provided in the region of the front end of the take-up body22.

The membrane24which is inserted into the interior of the take-up body22and which is made of an elastomer is a one-piece, rotationally symmetrical component which is elongate, hollow in the interior and closed at its front end. The membrane24is arched in a dome-shape to form an approximately semi-spherical dome36in the region of the closed front end, with the dome36of the membrane24projecting out of the take-up body22.

At its lower end, the membrane24is formed in hollow cylindrical manner in the region of the indentation38and sealingly covers the indentation38.

A further indentation40, into which a complementary formed latching section of the membrane24latchingly engages, is provided above the indentation38at the inner periphery of the take-up body22.

In the normal state (cf.FIG. 1), the membrane24in the region of the discharge passage34sealingly contacts the internal periphery of the take-up body22in the region of a contact section42. In the region of this contact section42, the inner jacket surface of the discharge passage34is designed as a paraboloid of revolution, with the membrane24having the same outer contour of a paraboloid of revolution at its outer periphery in this section. A discontinuous transition is provided between the outer contour of a paraboloid of revolution of the membrane24and the dome36at the upper end of the discharge passage34in the region of the dome36, whereby a discharge passage44is formed.

The support body26, which is likewise a rotationally symmetrical component made in one piece from plastic, is inserted into the interior of the membrane24. The support element26serves, on the one hand, to pre-stress the membrane24axially in the region of the contact section42and, on the other hand, to hold the membrane in the take-up body22. For this purpose, the support element is provided at its lower end with a ring-shaped projection46which can be latched into a correspondingly desired ring groove in the interior of the take-up body22. At its upper end, the support element extends up to and into the base region of the dome36. It is there received in a hollow cylindrical recess48at the inner front end of the membrane24.

In the region of the contact section42, the support element26is made in pin-shape, with the outer contour of the pin-shaped section likewise being made as a paraboloid of revolution. However, as the Figures show, there is a clear spacing between the outer jacket surface of the pin-shaped section of the pin element26and the inner peripheral area of the membrane24in this section which makes it possible for the membrane to deform inwardly in the direction of the support element26(cf.FIG. 2).

The support element26is provided approximately at the middle at its outer periphery with a peripheral latching lip50which latchingly engages into a complementary formed, ring-shaped latching recess at the inner periphery of the membrane24. The membrane is hereby lightly tensioned axially between the base of the dome36and the latching lip50.

AsFIG. 1shows, the membrane24with the support element26is inserted into the take-up body22such that, when the support element26is latched and when the membrane24is latched, the membrane contacts the inner periphery of the take-up body areally and. sealingly along the contact section42. A ring passage52(FIG. 2), which is preceded by at least one axial overflow passage54, is formed in the take-up body22at the inner orifice of the contact section42, the overflow passage in turn being preceded by a further ring passage56. Both the ring passage52as well as the overflow passage54and the ring passage56are bounded at the outer periphery by the take-up body22and at the inner periphery by the membrane24.

As in particularFIG. 2shows, a plurality of axial overflow passages58are provided in the membrane24and connect the interior of the membrane24to the outer side of the membrane. Liquid can hereby flow from the interior of the take-up body22into the ring passage56.

The support element26furthermore has a plurality of throughflow openings60at its lower side which are distributed over the periphery of the support element26and which extend in the axial direction.

The function of the valve shown inFIGS. 1 to 3is as follows:

In the state of rest, the membrane24of the valve20is in the position shown inFIG. 1in which the membrane24closes both the discharge passage34(FIG. 2) and the aeration passage32in an outwardly sealed manner such that no liquid can flow out of the interior of the container10and no contaminated air can penetrate into the interior of the container10.

A desired discharge pressure is applied for the discharge of liquid from the container10, for example by squeezing the at least regionally elastically deformable container10. Overpressure is hereby produced in the interior of the container10which propels out the liquid located in the container10through the discharge passage34(cf.FIG. 2). In this process, the liquid initially flows into the interior of the take-up body22, from there through the throughflow openings60into the interior of the membrane24and from there through the overflow passages58into the ring passage56. From there, the liquid enters into the ring passage52through the overflow passage54, with the pressure exerted on the membrane24by the liquid raising the membrane from the take-up body22inwardly in the direction of the support element26such that a ring gap, as is shown inFIG. 2, is created between the membrane24and the take-up body22. Subsequently, the liquid enters into the outflow passage44and collects as drops at the dome36such that an application of the drop is possible, for example in the eye of a user.

FIG. 3shows the state of the membrane24after the discharge pressure has been reduced. The overpressure in the interior of the container10is hereby reduced and the restoring forces of the pre-stressed elastic membrane24have the effect that it again firmly contacts the inner jacket surface of the contact region42of the take-up body22such that the discharge passage34is again sealingly closed.

The underpressure created in the container10, which is produced by the discharge of the liquid, subsequently has the effect that the lower marginal region of the membrane24, which has previously sealingly closed the aeration passage32or the indentation38, rises from the inner periphery of the intake body22, as is represented inFIG. 3. Ambient air can hereby subsequently flow into the interior of the container10via the sterile filter28and the aeration passage32and the indentation38until pressure compensation has been achieved between the ambient pressure and the internal container pressure. The corresponding air flow is indicated by arrows inFIG. 3.

If the valve is used in a dropper system which does not require any pressure compensation, the aeration passage32and the sterile filter28can be omitted.