Sealing device for drink packages

Abstract

The invention relates to a sealing device (3, 30) for sealing off an opening (5) of a plastic drink package. Said sealing device (3, 30) has a flexible collar (10) that is provided with an inward-facing surface (45) that is subject to the internal pressure. The collar (10), in the closed position of the sealing device (30), is functionally linked with a collar rim (11) of the opening (5) to be sealed off and is adapted to exert a pressure (K) thereon that increases in proportion to the internal pressure (P).

Description

[0001] The invention relates to a device for sealing drinks packages, in particular drinks packages of plastic which are under inner pressure, according to the preamble of the independent patent claim

[0002] From the state of the art there are known closures for drinks packages which are under an inner pressure, e.g. PET bottles. The closures of these packages require very large closure forces so that a sufficient sealedness is guaranteed between the sealing surfaces. The high operating forces resulting from this represent a disadvantage. Furthermore the closures have a very low failure tolerance and thus demand a very high precision on manufacture. The manufacture thus entails very great expense.

[0003] In order to achieve a sufficient pressing force and thus an adequate sealedness even with a high inner pressure, the closures known today comprise a thread Only by way of this is it possible to produce the required closure forces. On opening the closures the thread is cumbersome because it inhibits the escaping gas.

[0004] The most common closures are manufactured of plastic by way of injection moulding. Today's closures require them to be manufactured with very tight tolerances.

[0005] The object of the invention disclosed here lies in specifying a device for sealing drinks packages, in particular drinks packages of plastic which are under an inner pressure, which require no large closure forces, but however are leakproof even with large inner pressures in the container. In particular the device for sealing should be suitable for closures with a hinge and/or quality seal.

[0006] The object is achieved by the invention defined in the patent claims.

[0007] The invention lies in a sealing device for sealing an opening of a drinks package. The sealing device comprises a sealing means which is designed and arranged in a manner such that it produces a sealing force which is proportional to the inner pressure and which acts on a rim region of the opening to be sealed.

[0008] The sealing device is designed such that the sealing effect is largely independent of a large initial force. One sets the sealing effect or force by way of the design, dimensioning and arrangement of the sealing means and the surface exposed to the inner pressure.

[0009] The sealing means is formed completely or partly flexible compared to the surrounding elements in a manner such that it deforms as a result of a pressure difference (inner pressure). The sealing effect is achieved in that the deformation of the sealing means is hindered in a targeted manner so that a sealing force arises on account of the hindrance. Materials which may be processed by injection moulding and which have a Shore hardness which preferably lies in the region of 20 to 80 are preferred. The flexibility of the sealing means which is required for a smooth functioning is dependent on the geometry and the mechanical properties of the adjacent regions. Materials which have mechanical properties which are similar to those of silicone made good experience.

[0010] The invention disclosed here is especially suitable for single-part or multi-part closures of plastic. The sealing means may integrally form a part of the closure, but also be formed as a separate part. When required, the closures are preferably manufactured by way of multi-component injection moulding. Thus for example by way of a different material selection it is possible to integrate a device with a flexible sealing means into a closure which in comparison is less deformable.

[0011] The invention is described in more detail by way of the subsequent figures. Shown schematically and greatly simplified are:

[0012] FIG. 1 a first embodiment form of a sealing device;

[0013] FIG. 2 a detailed view of FIG. 1;

[0014] FIG. 3 the device of FIG. 1 in an opened position;

[0015] FIG. 4 a hinge closure in the closure position;

[0016] FIG. 5 the hinge closure according to FIG. 4 in an open position;

[0017] FIG. 6 a closure with a further embodiment form of a sealing device;

[0018] FIG. 7 the closure according to FIG. 6 in a frontal view;

[0019] FIG. 8 five embodiment forms of sealing means.

[0020] FIG. 1 very schematically shows a closure 1 with a sealing device according to the invention which serves to seal an opening 5. The representation shows the closure 1 with a closure body 2 and with a sealing means 3 in a sectional representation. The closure 1 here is located on a neck 4 of a container, whose opening 5 it sealingly closes. The sealing means 3 here consists of a separate element which at least in regions corresponds with inner surfaces of the closure body 2 and is supported on these.

[0021] The sealing means 3 comprises a collar 10 which in this representation is in releasable active connection with a rim of a neck (in the following neck rim) 11 of the opening 54 to be closed. The collar 10 in comparison to the closure body 2 is formed flexibly in a manner such that with an inner pressure it is increasingly is supported on the neck rim 11 and sealingly closes this by way of this.

[0022] The collar 10 is designed such that on placing the closure 1 onto the neck 4 it experiences a certain deformation by the neck rim 11 which produces an initial sealing effect.

[0023] The closure body 2 comprises two laterally arranged arms 6 which open into a ring 7. The ring 7 surrounds the neck 4 and comprises projecting blocking elements 8 which are fastened on the ring 7 and in the closure position are in engagement with a blocking edge 9 radially projecting on the neck 4. The closure 1 is securely closed by way of this. The closure 1 may be released in that the ring 7 is deformed by lateral pressing in a manner such that it becomes oval and releases the blocking elements 8.

[0024] The closure 1 comprises means for centering the closure 1 on the neck 4. These means which here are not shown in more detail may be designed as radially inwardly projecting ribs. They serve the positioning of the collar 10 with respect to the rim 11 of the opening 5 in the unloaded condition.

[0025] FIG. 2 shows the detail D of FIG. 1. One may recognise a part of the closure body 2 and of the sealing means 3. The collar 10 is in active connection with the neck rim 11 of the opening 5. The forces acting on account of an inner pressure are represented schematically by way of arrows. The inner pressure acting on the collar 10 has the effect that the collar is pressed with a force K against the neck rim 11 in a manner such that the opening 5 is sealingly closed The size of the occuring sealing force K may be set by the design of the collar 10.

[0026] The sealing effect may be additionally increased in that the neck rim 11 or the collar 10 comprises means which lead to a concentration of the forces responsible for the sealing effect. One or more annularly projecting elements or edges (not shown in more detail) arranged in the contact region between the collar 10 and the neck rim 11 are suitable.

[0027] FIG. 3 shows the closure according to FIG. 1 in an opened position. As may be recognised, the blocking elements 7 are no longer in engagement with the blocking edge 9 so that the closure may be freely withdrawn.

[0028] FIG. 4 shows simplified a hinge closure 20 of plastic in a perspective sectional representation. The hinge closure 20 which here is shown closed comprises a lower part 21 and an upper part 22 which are connected to one another via a hinge 23 (film hinge). The closure 20 is preferably manufactured by injection moulding of plastic.

[0029] The lower part 21 comprises an opening 5 which is sealingly closed by a sealing means 3. The sealing means 3 comprises a collar 10 which is in active connection with a neck rim 11 of the opening 5. The sealing means 3 is designed such that it exerts a sealing force onto the rim 11 which is proportional to the inner pressure, in a manner such that the opening is securely closed. The sealing means 3 is also here formed as a separate means. Of course it may however also be integrated into the hinge closure 20 or form part of this.

[0030] The upper part 22 comprises a hammer-like blocking element 25 which projects on an edge and which in the closure position is in engagement with a corresponding groove element 26 of the lower part 21 and closes the hinge closure. The blocking element 25 and the groove element 26 are designed in a manner such that they may be removed from the mould in an injection moulding mould without additional means such as slider, etc. The closure 20 may be opened in that the blocking element 25 is bent to the front relative to the groove element 26, away from the lower part.

[0031] FIG. 5 shows the closure 20 according to FIG. 4 in an opened position. One may recognise the film hinge 23 which linkedly connects the lower part 21 to the upper part 22. The sealing means 3 may be recognised in the inside of the upper part 22. The sealing means 3 is arranged in a bordering 29 which holds the sealing means and limits its lateral extension. The collar 10 of the sealing means 3 in comparison to the material of the closure consists of a relatively elastic material in a manner such that the collar 10 may be deformed without a great force effort.

[0032] The hammer-like blocking element 25 projects freely upwards from the edge of the closure upper part 22. The wall thickness corresponds roughly to that of the upper part 22. The blocking element 25 has a wider region 27 and a narrower region 28. The narrower region 28 is arranged between the wider region 27 and the upper part 22. The groove element 26 which is located at the front on the lower part 21 is designed in a manner such that it may be brought into engagement with the blocking element 25. The blocking element 25 advantageously engages into the groove element 26 from the outside. By way of this for example it is possible to provide a guarantee seal by way of attachment of a film which after closure of the closure 20 is applied around this and which must be removed before opening for the first time. At the same time the film is applied around the closure 20, the blocking element 25 and the groove element 26 such that the engagement between the blocking element 25 and the groove element 26 may no longer be released without removing the film.

[0033] The closure 20 is preferably screwed or knocked onto a container to be closed.

[0034] In a sectional representation FIG. 6 shows a closure 40 with a sealing device 30 according to the invention. The sealing device 30 is part of a closure cap 31 and corresponds with a neck rim 11 of an opening 5. The collar 10 of the sealing device 30 is here arranged at an inner angle of a with respect to the closure cap 31 or the rim 11. The collar 10 consists of a material which is flexible with respect to the surroundings and which is well deformable. The sealing device with the collar 10 is part of the closure cap 31 or is manufactured as a separate element and subsequently applied into the closure cap 31. The angle &agr; is directed to the demands on the sealing effect to be achieved given an inner pressure, the desired initial sealing force and the manufacturability. The inner contour of the collar 10 is preferably selected such that the collar may be simply removed from the mould on manufacture by way of injection moulding. According to the field of application one may form the inner surface cylindrically as long as the required elasticity of the collar 10 is ensured. The outer angle &agr;′ (of FIG. 8) is selected such that the collar 10 may easily be introduced into the opening, and on placing onto the neck rim 11 experiences a radial deformation which builds up an annular tension. By way of exploiting these annular tensions it is possible to produce an initial force acting sufficiently on the rim even with very elastic material, so that there results a sufficient initial sealing. By way of the flexibility of the collar 10 inaccuracies are compensated for the sealing. In contrast to the closure known from the state of the art the invention seals even with large inaccuracies.

[0035] The neck rim 11 is here part of the closure lower part 32, with an inner thread 33. The closure lower part may be screwed onto a conventional PET bottle. Of course the closure lower part 32 may also be designed as part of a drinks package. The closure lower part 32 comprises two lateral, diametrically opposite closure means which in regions project radially and which in each case have a recess 35 widening to the bottom. When the closure cap 31 has been placed on, correspondingly formed upper closure means 36 which are formed on the closure cap 31 via a web 38 engage into these recesses 35. The upper closure means 36 at the end of the web 38 comprises a broadening 39 which engages into the recess 35 with a positive fit. The closure means 34, 36 are designed such they may be manufactured in an injection moulding tool without a slider. The inner edge of the recesses 35 which is directed away from the closure cap 31 comprises an undercut. The broadening 39 of the upper closure means 36 engages into this undercut and by way of this secures the closure cap 31 from undesired release.

[0036] FIG. 7 shows the closure 40 of FIG. 6 in a front view. The geometry of the closure 40 is selected such that on placing the closure cap 31 onto the closure lower part 32 the collar 10 is deformed slightly inwards in the direction of the arrow by the active connection with the neck rim 11. The elastic material of the collar 10 resists this deformation which results in a pressing on the neck rim 11. This pressing effects an initial sealing effect. Arising inner pressure acts on the inner region of the collar 10 by which means the collar attempts to extend against the direction of the arrow A. This movement is prevented by the neck rim 11 and effects a concentration of the forces in this region. The collar 10 is designed such that it conducts forces into the interaction region between the collar 10 and the neck rim 11 in a targeted manner and thus a sealing force is produced which increases proportionally with an increasing inner pressure. The collar 10 may be formed such that on reaching a defined maximal pressure with a closure cap 31 is slips off the neck rim 11 in a targeted manner and is turned up to the outside so that the overcritical inner pressure is reduced. A dangerous jumping-off of the closure is prevented by way of this. The initial sealing effect may be influenced by measures which influence the position of the collar 10 with respect to the neck rim 11. These measures include: varying the thickness of the base of the closure cap 31; length of the webs 38; material accumulation in the regions of the lower and upper closure means 35, 36 which correspond with one another. By way of this it is possible to set the initial sealing effect in a targeted manner by way of simple measures. Shrinkage problems occurring on curing the plastics on manufacture may be compensated in a targeted manner.

[0037] The closure cap 31 comprises gas exit regions 40 which on opening effect a directed escape of gas.

[0038] FIG. 8 shows five various embodiment forms (a to e) of sealing means 30 in a perspective sectional representation. With a first sealing means 30 the collar 10 is arranged radially inwards. This first sealing means corresponds essentially to the sealing means 3 of the FIGS. 1 to 5.

[0039] The second sealing means 30 (b) comprises an obliquely inwardly running collar 10. The collar 10 has a constant wall thickness and is supported by ribs 41 arranged on the outside. This embodiment form is suitable for very large inner pressures. The region on which a neck rim lies is indicated by a dashed line 42.

[0040] The third sealing means 30 (c) corresponds essentially to the sealing means of FIGS. 7 and 8. This third sealing means 30 likewise comprises an inwardly inclined collar 10. The collar 10 has a wall thickness which reduces towards the edge. The pressure surface 45 of the collar 10 exposed to the inner pressure is shown hatched.

[0041] The fourth sealing means 30 (d) corresponds essentially to the third sealing means (c). This fourth sealing means however in the sealing region 42 on which it lies on a neck rim comprises projecting annular means which effect a concentration of sealing forces.

[0042] The fifth sealing means 30 comprises a collar 10 which has an inwardly directed (sharp) bend. The shape of the collar effects an additional concentration of the sealing forces in the sealing region 42. The shown sealing means a to e are in particularly suitable for hinge closures.

[0043] Further embodiment forms result to the man skilled in the art by the combination of the features of the described devices.

Claims

1. A sealing device (3, 30) for sealing an opening (5) of a drinks package of plastic, characterised by a flexible collar (10) which comprises an inwardly directed surface (45) exposed to the inner pressure, said collar (10) in a closure position of the sealing device (30) being in active connection with a neck rim (11) of the opening (5) to be sealed, in a manner such that the collar (10) is pressed onto the neck rim (11), wherein the pressing force (K) increases proportionally to the inner pressure (P).

2. A sealing device (3, 30) according to claim 1, characterised in that the collar (10) is directed radially inwards.

3. A sealing device (3, 30) according to claim 1, characterised in that the collar (10) is designed running obliquely inwards at an angle (&agr;).

4. A sealing device (3, 30) according to one of the preceding patent claims, characterised in that the collar (10) and/or the neck rim (11) comprises means which effect a concentration of the sealing force.

5. A sealing device (3, 30) according to patent claim 4, characterised in that the means are a circumferential, concentrically arranged bead.

6. A sealing device (3, 30) according to one of the preceding claims, characterised in that the collar (10) has a variable wall thickness.

7. A sealing device (3, 30) according to one of the preceding patent claims, characterised in that the collar (10) comprises a (sharp) bend.

8. A sealing device (3, 30) according to one of the preceding patent claims, characterised in that the collar (10) is supported by ribs (41).

9. A sealing device (3, 30) according to one of the preceding patent claims, characterised in that the collar (10) has a hardness which lies in the region of 20 to 80 Shore A.

10. A hinge closure (20) with a sealing means (3, 30) according to one of the preceding patent claims.