Closure

A closure for a container with a cap connecting to a neck of the container has at least one cutter edge placed around a central axis internal of the neck. The edge cuts through a closure film as axially displaced on a holding sleeve, which is held centrally by the cap with a flexible skirt. The holding sleeve contains a component for mixing with the contents of the container. A screw cap holds an initial non-puncturing position and, a stop position after additional screwing on, at which the film is punctured. The cap remains permanently on the neck of the container, and includes a pouring opening. In the stop position, the container contents flow toward the pouring opening. When the screw cap is back into its initial position, flow to the pouring opening is interrupted.

The invention relates to a closure for a container having contents, particularly a bottle or the like made of plastics material, glass or the like, comprising a cap, particularly of plastics material, to be sealingly connected to a neck of the container, which neck has a rim, and comprising at least one knife edge disposed in the region of the inside width of the neck around the center axis of the cap for severing a sealing film or foil upon axial displacement of the at least one knife edge through the sealing film or foil, which knife edge is disposed on a receptacle held substantially centrally by the cap via a flexible apron and is movable relatively to the cap toward the sealing film or foil, which receptacle contains an ingredient to be mixed with the contents of the container, and further comprising a central union, having a male thread, on an upper transverse wall of the cap and a screw cap that can be screwed down onto, and unscrewed up from, the same by means of actuating means disposed on its inside end face, by means of which, when the screw cap is screwed onto the central union, the receptacle with its at least one knife edge can be moved toward the sealing film or foil, which screw cap has an initial screwing position in which the sealing film or foil is still intact and, after continued screwing, a final screwed position in which the sealing film or foil has been pierced by the at least one knife edge.

Such closures serve to keep an ingredient of the container's contents separate from the main component thereof during a waiting or storage time until the time of usage has arrived, particularly to avoid premature impairment of the quality or usability of the entire contents as might occur with time after mixing due to aging or the like. In the case of beverages or foodstuffs in general this is simply the time when the user wishes to consume the contents of the container or bottle, while in the case of, for example, chemicals, paints, enamels, cleaning agents, etc. it is the time when they are to be used. In the case of foodstuffs, the component to be mixed in may consist of, for example, vitamins or mixtures thereof and in the case of paints or plastics, of activators such as pigments or accelerators (e.g. oxidizing agents), etc.

A closure of this type is disclosed in WO 2004/113 184 A-2, in which case the cap is designed as a first screw cap and the screw cap as a second screw cap. After the sealing film or foil has been opened and the ingredient to be mixed into the contents of the container has been released, this prior closure, i.e. the first screw cap together with the second screw cap, must be completely unscrewed from the neck of the container when it is desired to withdraw some of the mixed contents of the container. When it is desired to re-close the container after partially removing the contents of the container, it is necessary to screw the closure back on again as a whole. Thus, when unscrewing and removing the contents of the container, e.g. when drinking from a bottle if it contains a beverage, and when the cap is to be screwed back on for the purpose of re-closing the container or bottle, the user has to use both hands, at which time there is always the risk, due to the removal of the cap from the container or bottle, of the cap dropping out of the hand of the user or drinker.

In addition, closures known as so-called sports caps are known which have to be only partially unscrewed in order to remove the container's contents, i.e. they can remain on the neck of the container or bottle, because such a sports cap has an outlet opening which is opened even when only partially unscrewed and can be re-closed by rescrewing. Such sports caps permit an athlete, particularly a cyclist, to drink during sports activity without having to use both hands and without risking the loss of the closure of the bottle when so doing.

The object of the invention is to provide a closure of the type mentioned above designed in a way that is suitable for fulfilling the functions of a sports cap.

A first solution to this problem consists in thata) the cap remains on the neck of the bottle after it has been sealingly connected thereto,b) the screw cap has a decanting and/or drinking opening of the sports cap type,c) at least one first axial passageway for the contents of the bottle is provided radially between the first cap and the receptacle,d) the receptacle is guided in a sliding manner centrally in a coaxial guide in the transverse wall of the cap, which initially bears axially against a substantially radial inside surface of the cap, the receptacle, by bearing against the cap, providing a seal between the container and the screw cap and thus the environment, and when it moves with its at least one knife edge concentrically relatively to the sealing film or foil to an end position, it is capable of severing the sealing film or foil, and in this end position the sealing film or foil has been at least partially severed, the ingredient to be mixed in has been released into the contents of the bottle, and another passageway has been opened between the receptacle and the cap,e) the screw cap, on its inside covering surface, and the receptacle, on its end face opposite thereto, together comprise, as actuating means, a concentric connecting pair consisting of a plunger and a counterpart mating therewith, which interengage axially immovably, the plunger and its counterpart being positioned axially relatively to each other such that, by said continued screwing of the screw cap on the central union to the final screwed position, the container's contents can be released to flow to the screw cap and its decanting and/or drinking opening, this being achieved by the receptacle being moved, during such continued screwing, toward the sealing film or foil to cause the at least one knife edge to pass through the sealing foil or film to break the seal between it and the cap, andf) when the screw cap is turned in the reverse direction, i.e., back to its initial screwing position, the receptacle can be moved by the actuating means back to its sealing position against the cap such that the passageway to the screw cap and its decanting opening is again blocked.

According to the invention, after mixing of the ingredient to be mixed in has taken place, the closure does not have to be completely removed in order to withdraw at least some of the mixed contents of the container and does not have to be laboriously replaced for the purpose of closing the container and sealingly connecting it to the neck of the container, as is the case with the prior art elaborated above, where the entire closure has to be screwed on again after it has been opened by being completely unscrewed. By contrast, in the case of the subject matter of the invention, the cap remains on the neck and partial screwing of the screw cap toward its final screwed position to break the above-described seals is sufficient to permit the contents of the container to be decanted. This is particularly advantageous in the case of foodstuff or beverage bottles during athletic events such as cycling.

A second solution to the problem of the invention consists in thata) the cap remains permanently on the neck of the bottle after it has been screwed on,b) the screw cap has a decanting and/or drinking opening of the sports cap type,c) at least a first passageway for the contents of the bottle is provided radially between the cap and the receptacle,d) an axial intermediate piston is centrally provided initially bearing against a substantially radial inside surface of the cap between the cap and the receptacle and is movably guided in a coaxial guide in the transverse wall of the cap, which intermediate piston is capable, by bearing against the cap, of forming a seal between the container and the screw cap and thus the environment, and on the other hand, as it moves jointly with the receptacle, of moving the same and its at least one knife edge concentrically relatively to the sealing film or foil to an end position for the purpose of severing the sealing film or foil, in which end position the sealing film or foil has been at least partially severed, the ingredient has been released into the bottle's contents, and another passageway between the intermediate piston and the cap has been opened,e) the screw cap, on its inside covering surface, and the intermediate piston, on its end face opposite thereto, together comprise, as actuating means, a concentric connecting pair consisting of a plunger and a counterpart mating therewith, which interengage axially immovably, the plunger and its counterpart being positioned axially relatively to each other such that, by said continued screwing of the screw cap on the central union to the final screwed position, the container's contents can be released to flow to the screw cap and its decanting and/or drinking opening, this being achieved by the intermediate piston being moved, during such continued screwing, toward the sealing film or foil to break the seal between it and the cap and thus to cause the at least one knife edge to pass through the sealing foil or film, andf) when the screw cap is turned in the reverse direction, i.e., back to its initial screwing position, the intermediate piston can be moved by the actuating means back to its sealing position against the cap such that the passageway to the screw cap and its decanting opening is again blocked.

This second solution differs from the aforementioned first solution essentially in the fact that the actuating means and the receptacle are designed as two separate parts. At the same time, on the counterpart of the actuating means the rod extension comprising the coupling sleeve is designed as a piston at its end facing the receptacle. This piston is referred to below as the intermediate piston, since it is disposed between the receptacle and the opposing end face of the first screw cap. The receptacle may in this case have a flat end face as an axial bearing surface for the intermediate piston, against which the intermediate piston can bear and entrain the receptacle, as soon as the screw cap, upon continued screwing on the central union, moves or pushes the receptacle in the opening direction for the purpose of piercing the sealing film or foil.

At first glance, this second solution may appear to be more complicated, more costly and therefore less advantageous due to splitting the design of the receptacle and actuating means, which are present as one piece in the first embodiment. However, this second solution has two important advantages over the first solution:

1. This second solution can be produced and assembled at lower cost. On the one hand, the receptacle and intermediate piston as relatively simply shaped parts can each be produced in a relatively simple manner. On the other hand, the ingredient to be accommodated by the receptacle and later mixed in can be inserted and enclosed by the sealing film or foil while the receptacle is lying on its substantially flat back, e.g., on an assembly line.

2. In both the first and the second embodiment, when the second screw cap is screwed to its final screwed position for the purpose of piercing the sealing film or foil and possibly also the foil seal, the flexible apron is deformed, which is, of course, adapted to permit the receptacle to be moved or displaced in the required manner. It is to be understood that this apron, regardless of its flexibility of deformation, asserts a certain though not very pronounced degree of resistance. If, then, the closure according to the invention is re-closed by screwing the second screw cap in the reverse direction, i.e. back to its initial screwing position, then in the first embodiment, the receptacle must also be entrained during the corresponding backward movement of the apron, while in the second embodiment, the receptacle can advantageously remain behind. Re-closing the container or bottle therefore requires less screwing effort, which is important with regard to the desired possibility of single-handed operation.

The sealing connection of the cap with the neck of the container can be achieved in various ways, e.g., by welding or gluing, etc. However, the most common method at present is to design the cap corresponding to the closest prior art mentioned above as a first screw cap, so that the above-mentioned screw cap becomes a second screw cap. The difference, of course, resides in the fact that in the above-described prior art according to the document cited, this first screw cap and therefore the entire closure must be unscrewed if it is desired to gain access to the contents of the container, while in the case of the subject matter of the invention, the cap, after being sealed to the neck of the bottle, can remain permanently thereon, particularly when it is designed as a first screw cap. If it has been welded on, sealed on, shrunk on, etc., its remaining thereon is a matter of course.

Therefore, the closure according to the invention is preferably designed such that the cap as a first screw cap has a sleeve section with a female thread adapted for screwing onto a male thread of a neck, having a rim, of a container, and the screw cap functions as a second screw cap.

Therefore the invention relates particularly to a closure having a first screw cap, particularly of plastics material, which has a sleeve section with a female thread for screwing onto a male thread on a neck, displaying a rim, of a container having contents, particularly a bottle or the like of plastics material, glass or the like, comprising at least one knife edge disposed in the region of the inside width of the neck around a center axis of the first screw cap for severing a sealing film or foil upon axial displacement of the at least one knife edge through the sealing film or foil, said knife edge being disposed on a receptacle held substantially centrally by the first screw cap via a flexible apron and capable of moving relatively to the first screw cap toward the sealing film or foil, which receptacle contains an ingredient to be mixed into the contents of the container, and comprising a central union, having a male thread, on an upper transverse wall of the first screw cap and a screw cap that can be screwed down onto, and unscrewed up from, the same with actuating means disposed on its inside end face, by means of which, when the screw cap is screwed onto the union, the receptacle with its at least one knife edge can be moved toward the sealing film or foil, this second screw cap having an initial screwing position, in which the sealing film or foil is still intact and, after continued screwing, a final screwed position, in which the sealing film or foil has been pierced by at least one knife edge.

Starting from this known design, the corresponding variant of the first solution to the problem of the invention consists in thata) the first screw cap remains permanently on the neck of the bottle after it has been screwed on,b) the screw cap has a decanting and/or drinking opening of the sports cap type,c) at least a first passageway for the contents of the bottle is provided radially between the first screw cap and the receptacle,d) the receptacle is guided in a sliding manner centrally in a coaxial guide in the transverse wall of the first screw cap, which initially bears axially against a substantially radial inside surface of the first screw cap, the receptacle providing, by bearing against the first screw cap, a seal between the container and the second screw cap and thus the environment, and when it is moved concentrically relatively to the sealing film or foil to an end position, it is capable of severing this sealing film or foil with its at least one knife edge, in which case, in said end position (FIGS. 3 and 4), the sealing film or foil has been at least partially severed, the ingredient to be mixed in has been released into the contents of the bottle and another passageway has been opened between the receptacle and the cap,e) the screw cap, on its inside covering surface, and the receptacle, on its end face opposite thereto, together comprise, as actuating means, a concentric connecting pair consisting of a plunger and a counterpart mating therewith, which interengage axially immovably, the plunger and its counterpart being positioned axially relatively to each other such that, by said continued screwing of the screw cap on the central union to the final screwed position, the container's contents can be released to flow to the screw cap and its decanting and/or drinking opening, this being achieved by the receptacle being moved, during such continued screwing, toward the sealing film or foil to break the seal between it and the cap and thus to cause the at least one knife edge to pass through the sealing foil or film, andf) when the screw cap is turned in the reverse direction, i.e., back to its initial screwing position, the receptacle can be moved by the actuating means back to its sealing position against the cap such that the passageway to the screw cap and its decanting opening is again blocked.

The corresponding variant of the second solution to the problem of the invention then consists in thata) the first screw cap remains permanently on the neck of the container after it has been sealingly connected thereto,b) the second screw cap has a decanting and/or drinking opening of the sports cap type,c) at least a first passageway for the contents of the bottle is provided radially between the first screw cap and the receptacle,d) an axial intermediate piston is provided centrally which initially bears against a substantially radial inside surface of the first screw cap between the first screw cap and the receptacle and is movably guided in a coaxial guide in the transverse wall of the first screw cap, said intermediate piston, by bearing against the first screw cap, being capable of forming a seal between the container and the screw cap and thus the environment and, on the other hand when it is moved jointly with the receptacle, of moving the same and its at least one knife edge concentrically relatively to the sealing film or foil to an end position for the purpose of severing the sealing film or foil, in which end position the sealing film or foil has been at least partially severed, the ingredient to be mixed in has been released into the bottle's contents and another passageway between the intermediate piston and the first screw cap has been opened,e) the second screw cap, on its inside covering surface, and the intermediate piston, on its end face opposite thereto, together comprise, as actuating means, a concentric connecting pair consisting of a plunger and a counterpart mating therewith, which interengage axially immovably, the plunger and its counterpart being positioned axially relatively to each other such that, by said continued screwing of the second screw cap on the central union to the final screwed position, the container's contents can be released to flow to the second screw cap and its decanting and/or drinking opening, this being achieved by the intermediate piston being moved, during such continued screwing, toward the sealing film or foil to break the seal between it and the cap and thus to cause the at least one knife edge to pass through the sealing foil or film, andf) when the second screw cap is turned in the reverse direction, i.e., back to its initial screwing position, the intermediate piston can be moved by the actuating means back to its sealing position against the cap such that the passageway to the second screw cap and its decanting opening is again blocked.

The neck of the container may initially be hermetically sealed by a foil seal which has been sealingly attached to a circular sealing surface on the rim of the neck and which upon movement of the second screw cap to its final screwed position, like the sealing film or foil, is penetrated by at least one knife edge on the receptacle.

It is of particular advantage if the male thread on the central union forms a quick thread with the thread of the second screw cap such that less than one turn of the second screw cap, in the one direction of rotation, is necessary to open the container and, in the reverse direction of rotation, to close the same. This makes it easier for the user to hold the container or bottle in one hand and to open and close the second screw cap using the thumb and index finger of the same hand.

It has been found useful in such cases to place the plunger on the inside covering side of the second screw cap and a coupling sleeve forming the counterpart on the opposite side of the receptacle.

According to a preferred embodiment, the plunger is capable of rotation but engages the coupling sleeve immovably in the axial direction. However, it is obvious that, if necessary, a suitable thread pair can be provided between the plunger and the coupling sleeve, which contributes to the amount of displacement of the coupling sleeve relative to the first screw cap when the second screw cap is being screwed.

On the other hand, it may also be sufficient in some cases for the plunger and the coupling sleeve to engage by a force fit. However, if a thread pair is provided, a left-hand thread pair is preferred.

Advantageously, the receptacle has a coaxial rod extension forming the coupling sleeve as counterpart, and the outer periphery of the rod extension represents, at its base, with a coaxial through opening of corresponding diameter in the transverse wall of the first screw cap, the coaxial guide which in the initial screwing position of the second screw cap forms a further seal between the receptacle and the first screw cap.

Advantageously, on the top side of the receptacle and on the bottom side of the first screw cap there may be provided one or more additional seals which are in each case in the form of an annular gasket.

The first passageway can be provided in a retaining ring for the receptacle, which ring surrounds the receptacle and is connected thereto via the flexible apron, which permits relative movement between the axially movable receptacle and the retaining ring, which can be immovably attached to the inside circumferential surface of the first screw cap.

In addition, the sealing film or foil can be sealingly attached to an edge of the retaining ring facing the foil seal, if present, for the purpose of enclosing the ingredient to be mixed in in the receptacle and, upon said displacement of the receptacle by continued screwing of the second screw cap on the central union to the final screwed position, can be pierced by the knife edge jointly with the foil seal.

Depending on the axial distance between the sealing film or foil and the foil seal, the former may be pierced slightly in advance of the foil seal.

The other passageway may be formed by axial notches provided at intervals along the periphery of the rod extension of the coupling sleeve (the counterpart), which enter the region of the coaxial guide and thus begin to mate with the walls of the coaxial through opening in the first screw cap only when the second screw cap approaches its final screwed position when being screwed down.

Advantageously, the first screw cap displays an encircling flexible sealing lip above its female thread adapted for screwing onto the male thread of the container neck to bear against the rim of the neck initially still closed by the foil seal.

Preferably, the knife edge is serrated, at least over part of its periphery.

It has proven to be advantageous to provide the retaining ring in a bushing open to the container provided on the inside circumferential surface of the first screw cap and forming a part thereof, which is elastically expandable upon insertion of the retaining ring and has a catch to receive it.

The sealing lip can then be formed on the free edge of the bushing facing the container, and in addition, when the first screw cap is screwed onto the container for the purpose of remaining thereon, it can be expanded by said rim and can then be squeezed between said rim and the wall of the first screw cap.

It is advantageous for the second screw cap to have an internal collar which remains inside the central union after the second screw cap has been screwed onto the first screw cap and to have on its outside surface at least one encircling sealing lip adapted to form a seal against the inside wall of the central union. This ensures that the container's contents, after passing to the decanting opening, cannot be lost even partially to the environment by flowing past the second screw cap.

It is preferred for the second screw cap and the central union to comprise a left-hand thread pair.

FIGS. 1,3and5show a closure1comprising a first screw cap2, particularly of plastics material, which has a sleeve section4with a female thread3adapted for screwing onto a male thread5of a neck7of a container9having contents8, particularly a bottle or the like of plastics material, glass or the like, which neck7has a rim6.

The closure1has at least one knife edge11disposed in the region of the inside width of the neck7around a center axis10of the first screw cap2for severing a sealing film or foil12upon axial displacement of the at least one knife edge11through the sealing film or foil12, said knife edge11being disposed on a receptacle14held centrally via a flexible apron13by the first screw cap2and movable relative to the first cap2toward the sealing film or foil12, which receptacle14contains an ingredient15to be mixed into the contents8of the container9.

In addition, a central union17having a male thread16on an upper transverse wall of the first screw cap2and a second screw cap19that can be screwed down onto, and unscrewed up from, the same with actuating means21disposed on its inside end wall20, by means of which, when the second screw cap19is screwed on the central union17, the receptacle14with its at least one knife edge11can be moved toward the sealing film or foil12, this second screw cap19having an initial screwing position according toFIGS. 1 and 2, in which the sealing film or foil12is still intact and, after continued screwing, a final screwed position, as shown inFIGS. 3 and 4, in which the sealing film or foil12has been pierced by at least one knife edge11.

According to the invention:a) the first screw cap2remains permanently on the neck7of the bottle9after it has been screwed on,b) the second screw cap19has a decanting and/or drinking opening22of the sports cap type,c) at least one first axial passageway23for the contents8of the bottle is provided radially between the first screw cap2and the receptacle14as soon as the latter has been opened by destruction of the sealing film or foil12;d) the receptacle14is guided in a sliding manner centrally in a coaxial guide26in the transverse wall18of the first screw cap2, which initially bears axially against a substantially radial inside surface24of the first screw cap2, providing, by bearing against the first screw cap2, a seal between the container9and the second screw cap19and thus the environment and, upon its movement concentrically relatively to the sealing film or foil12to an end position, is capable of severing this sealing film or foil12with its at least one knife edge11, in which end position (FIGS. 3 and 4) the sealing film or foil12has been at least partially severed, the ingredient15to be mixed in has been released into the contents8of the bottle and another passageway27(FIGS. 3 and 4) has been opened between the receptacle14and the first screw cap2,e) the second screw cap19, on its inside covering surface, and the receptacle14, on its end face28opposite thereto, together comprise, as actuating means21, a concentric connecting pair consisting of a plunger29and a counterpart30mating therewith, which interengage axially immovably, the plunger29and its counterpart30being axially positioned relatively to each other such that, by said continued screwing of the second screw cap19on the central union17to its final screwed position, the container's contents8can be released to flow to the second screw cap19and its decanting and/or drinking opening22, this being achieved by the receptacle14moving, during such continued screwing, toward the sealing film or foil12to break the seal between it and the first screw cap2and pierce the sealing foil with its at least one knife edge11, andf) when the second screw cap19is turned in the reverse direction, i.e., back to its initial screwing position, the receptacle14can be moved by the actuating means2back to its sealing position against the first screw cap2such that the passageway to the second screw cap19and its decanting opening is again blocked.

In the final screwed position, the sealing film or foil12has been at least partially severed, the ingredient15to be mixed into the bottle's contents8has been released and a second passageway27for the container's contents8has been opened. In the embodiment shown, the neck7of the container9is initially hermetically sealed by means of a foil seal31sealingly attached to a circular sealing area32(FIG. 2) on the rim6of the neck7. When the second screw cap19is moved to its final screwed position, the foil seal31, like the sealing film or foil12, is pierced, as clearly shown inFIGS. 3 and 4, in order to release the container's contents8.

A design of the knife edge11is preferred which does not cause complete severing of the sealing film or foil12and possibly of the foil seal31but rather ensures that these foils remain intact at some point on their circumference such that they are only bent downwardly into the container, as is clearly shown in, say,FIGS. 3 and 5, in which case the passageway formed must naturally be large or wide enough for the ingredient15, here in the form of a tablet, to drop into the container9and its contents8.

The male thread16on the central union17preferably forms a quick thread16,33with the thread33of the second screw cap19such that less than one turn of the second screw cap19is necessary to open the container9in one direction of rotation and to re-close the same in the other direction of rotation.

In the embodiment shown, the plunger29is disposed centrally on the inside of the second screw cap19and the coupling sleeve30centrally on the opposite side of the receptacle14.

The plunger29can be axially locked in position in the coupling sleeve30but is free for rotation therein, cf. catch50.

Alternatively, the plunger29and the coupling sleeve30may be mutually force-fitted.

It would also be possible for the plunger29and coupling sleeve30to be connected by a thread pair.

On the back34of the receptacle14, the counterpart30is formed by a coupling sleeve-forming coaxial rod extension, whose outer circumference at its base represents the coaxial guide26with a coaxial through opening of corresponding diameter in the traverse wall18of the first screw cap2, which in the initial screwing position of the second screw cap19forms a seal between the receptacle14and the first screw cap2, which in the initial screwing position of the second screw cap19forms a seal between the receptacle14and the first screw cap2.

On the back34of the receptacle14several additional seals36and37are provided which in each case can be caused to bear against the first screw cap2in the form of an annular gasket.

The first passageway23is provided in a retaining ring38for the receptacle14, which retaining ring surrounds the receptacle14and is connected thereto via the flexible apron13, which permits a relative movement between the axially movable receptacle14and the retaining ring23which can be immovably attached to the inside circumference39of the first screw cap2.

The sealing film or foil12is sealingly attached to an edge40of the retaining ring23facing the foil seal31for the purpose of enclosing the ingredient15, advantageously in the form of a tablet, on the receptacle14, which sealing film or foil12, upon said movement of the receptacle14, may be severed by the knife edge11of said receptacle14just in advance of the foil seal31.

The third passageway is formed by notches41provided at intervals on the periphery of an attachment on the coupling sleeve30, which move into the region of the coaxial guide26and thus mate with the walls of the coaxial through opening of the first screw cap2only when the second screw cap10approaches its final screwed position shown inFIG. 3as it is being screwed down.

The first screw cap2has an encircling flexible sealing lip42above its female thread3adapted for screwing onto the male thread5on the neck7of the container9to bear against the rim of the neck initially closed by the foil seal31. Cf.FIG. 2.

As the figures illustrate, in the embodiment shown the knife edge11is serrated, at least over part of its periphery, in the present case with individual tips51, which facilitate severing of the sealing film or foil12and the foil seal31.

Advantageously, the retaining ring38is affixed in a bushing47open to the container and provided inside the first screw cap2and forming a part thereof, which is elastically expandable upon insertion of the retaining ring38and has a catch46to receive it.

The sealing lip42is formed on the free edge of the bushing47facing the container9. The sealing lip42is capable of being expanded by the rim6when the first screw cap2is screwed onto the container9for the purpose of remaining thereon and can then be caught between the rim6and the wall of the first screw cap2and be squeezed to cause a sealing effect.

The second screw cap19has an internal collar43which remains inside the union17after the second screw cap19has been screwed onto the first screw cap2and has on its outside surface at least one encircling sealing lip44adapted to form a seal against the inside wall45of the union17.

Advantageously, the second screw cap19and the union17have a left-hand thread pair16,33, since it is customary to open a screw cap of, say, a drinking bottle by turning it to the left.

The closure functions as follows:

First of all, a transparent plastic cap48, shown inFIG. 1as the tamper-evident seal, is torn off. In order to open the container or bottle9, the second screw cap19is turned to the left until the stop49, as shown inFIG. 3, is reached. During this movement, the plunger29and the coupling sleeve30move the receptacle14to the opening position shown inFIG. 3as a result of the left-hand thread of the second screw cap19. The knife edge11has now pierced the sealing film or foil12and the foil seal31with its tooth tips; both films or foils are bent downwardly into the container9or bottle and permit the tablet15to drop into the container's contents8and dissolve therein. The container's contents8can then pass through the passageway23(first passageway), of which several are provided, distributed inside the container ring38, and pass between the end face34or the back of the receptacle14(second passageway27) and further through the notches41(third passageway) and then through the decanting and/or drinking opening22.

When the container9or bottle is re-closed, the second screw cap19is screwed right back to its initial position, shown inFIG. 5, during which movement the receptacle14is entrained and comes to bear sealingly against the end face24of the first screw cap2. The notches41also move back up as shown inFIG. 3such that the third passageway at the coaxial guide26opened previously is closed again.

The second embodiment of the invention is illustrated inFIGS. 8 to 11, andFIGS. 2,4, and6also pertain thereto. The same parts are given the same reference numerals as in the first variant.

In this embodiment, the receptacle14and the actuating means21form separate units.

In this case, an axial intermediate piston25, having a bottom side35, is provided between the first screw cap2and the receptacle14bearing against a substantially radial inside surface24of the first screw cap2and guided for movement in a coaxial guide26in the transverse wall18of the first screw cap2. This intermediate piston25is capable, on the one hand because it bears against the first screw cap2, of sealing the container9or the bottle against the escape of contents in the direction of the second screw cap19and its decanting or drinking opening22, and on the other hand when it is moved or displace jointly with the receptacle14, of moving the same and its at least one knife edge11concentrically relatively to the sealing film or foil12for the purpose of severing the same in a final screwed position (FIGS. 3 and 4).

To this extent the function of the second embodiment corresponds to that of the first embodiment.

A difference in the function of these two embodiments consists in that when the second screw cap2is unscrewed back to its initial screwing position for the purpose of re-closing, the receptacle14is no longer entrained by the intermediate piston25but rather can remain in position.

It has proven to be advantageous to provide one or more gaskets on the top side and possibly also on the bottom side35of the intermediate piston25which can each be in the form of an annular gasket bearing against the first screw cap2and against the receptacle14respectively.