EP0701949A2 - Child-proof container closure - Google Patents

Abstract

The threaded neck (3) is made of plastic deformable under finger pressure. Teeth (2,5) near the threaded neck and screw cap (1) engage when the screw cap is completely screwed on. The screw cap can only be unscrewed when either the threaded neck and or the screw cap is deformed near the teeth so to disengage. At least one radial protuberance (17) between the threaded neck and the screw cap is positioned on the threaded neck on screw cap and staggered in a peripheral direction to the teeth. The radial distance between the outermost surface of the protuberance and the axis (18) of the screw cap corresponds to the inner radius of the screw cap axially outside the threaded part.

Description

The present invention relates to a container closure with a threaded connector provided on a container and a screw cap that can be screwed onto it, at least the threaded connector consisting of a plastic material that can be deformed by finger pressure, and toothing elements are provided in the area of the threaded connector and the screw cap, which are screwed together when the screw cap is fully screwed on Stand in engagement and only allow the screw cap to be unscrewed if either the threaded connector and / or the screw cap are deformed in the region of the toothing elements in order to disengage the toothing elements.

Such a container closure is commonly known as a "childproof closure". For further details and general properties of such container closures, reference is made to German patent application P 44 00 993.3, which is co-pending for the same applicant, the content of which is fully incorporated into the present application by this reference. The present invention is also based on the present invention earlier closure applicable applicable, but not limited to this. As already described in this earlier application, in the case of the container closures in question here, either the closure caps or the threaded connector can be deformed in order to disengage the toothing elements on the screw cap and threaded connector of a lower closure part. Since the screw cap has an internal thread and the threaded connector has an external thread and accordingly the toothing elements are located on the inside of the screw cap or on the outside of the threaded connector, either the threaded connector with its toothing must be pressed radially inward in the area of the toothing, or the screw cap must be moved radially outwards with their toothed areas, which is generally done by so-called "ovalizing", for example, by pressing the screw cap together at two opposite points, which are offset by 90 ° relative to the toothing elements. However, the application of the present invention is predominantly, if not exclusively, directed to a variant in which the threaded connector of the container closure deforms, i.e. the toothing elements are pressed radially inward, while the screw cap consists of a material that is harder than the threaded connector of the container closure which is less easy to deform.

The preferred material for the closure lower parts having the threaded connector is polyethylene. This applies in particular to so-called bellows closures, in which the threaded connector is connected via a bellows to a so-called closure foot, which in turn is fixed in a container opening. Such bellows closures must consist of a relatively flexible, easily deformable material so that the bellows can be turned in and out. But also for the compression of the threaded connector itself, in order to disengage the toothing elements on the threaded connector and screw cap, it is necessary that the threaded connector consists of a sufficiently easily compressible, deformable and flexible material. At the same time, the material must of course be sufficiently resistant to a wide variety of container contents and must also withstand the mechanical loads that occur without damage such as cracks or the like occurring. All of these properties are very well fulfilled by polyethylene, but this does not exclude that other materials with similar properties could also be used for the lower part of the closure or the threaded connector.

A disadvantage of the relatively easy deformability of a material such as polyethylene is, however, that the elasticity of the material is not always sufficient to completely restore the original shape after deformation. In other words, the threaded connector Pressed together in the radial direction at two opposite points and then released again, part of this deformation is retained even after the threaded connector has been released again. This means that when the screw cap is subsequently screwed on, the engagement of the toothing elements on the screw cap and threaded connector is less deep than in the original state. After repeated deformations and after a certain wear of the teeth by frequent opening and screwing of the closure, this can lead to the fact that the toothing elements do not engage in one another or only very slightly so that the closure can be pressed without unscrewing the threaded connector without excessive force by unscrewing the screw cap can be opened.

The present invention is therefore based on the object of providing a container closure in which the problem of the lack of functional reliability after prolonged use of the closure is eliminated, or at least alleviated.

This object is achieved in that the threaded connector has a radially outward projection in a region offset in the circumferential direction from the toothing elements.

Since this projection is offset in the circumferential direction relative to the toothing elements, preferably by approximately 90 °, it has a tendency to move outward in the radial direction when the toothing elements are pressed radially inward. This so-called ovalizing has already been mentioned above in connection with the screw cap.

Due to the limited elasticity of the material, however, it can be assumed with the threaded connector that such deformation will not be completely reversed after the threaded connector is released, i.e. the threaded connector maintains a shape in which the areas with the toothing elements radially inwards and the areas are pressed outwards with one or more radial projections. The screw cap screwed onto such a threaded connector, however, ideally has a circular shape and at the same time consists of a significantly harder, less easily deformable material, which also has better elastic restoring forces. If such a screw cap is screwed onto the still slightly deformed threaded connector, at least towards the end of the screwing process, not only do the toothing elements on the screw cap and threaded connector engage with one another, but also the projection offset by 90 ° to the toothing elements with a corresponding area of the inner surface the screw cap. This means that the radial projection additionally pressed outwards due to the deformation is pushed back radially inwards again from the inner wall of the screw cap, i.e. the initially remaining deformation of the threaded connector is actively reversed in this way by the screw cap, so that the threaded connector essentially takes on the ideal circular shape again. At the same time, the areas of the threaded connector with the toothing elements move radially outwards and thus improve the engagement with the toothing elements of the closure cap. The projection can be designed in the manner of a radially projecting cam and of course preferably has dimensions such that its outermost surfaces or points which engage the inner surface of the screw cap have the same radial distance from the imaginary axis of the screw cap as the inner surface of the screw cap itself. Thus, the cam or the corresponding area of the threaded connector is pushed back exactly when the screw cap is screwed on in the position which corresponds to the exact, circular shape of the threaded connector. The exact shape of the cam or projection is of secondary importance. The cam and / or the lower edge of the screw cap can, for. B. have inclined ramp surfaces to facilitate the engagement of the cam and inner surface of the screw cap. Optionally, two diametrically opposed cams or projections are provided, which are arranged in a position offset by 90 ° to diametrically opposed toothing elements on the threaded connector.

The axial position of the cam is of course chosen so that when the screw cap is completely screwed onto the threaded connector, it lies at least partially within the screw cap and engages with the inner surface of the screw cap, but remains axially outside the thread of the screw cap, since otherwise it unscrews the screw cap Cap could hinder. However, it would also be possible that the projection, analogous to the toothing of the screw cap in DE-44 00 993.3 already mentioned above, could be arranged along an imaginary continuation of the thread, in this case the threaded connector.

Preferably, however, the projection or cam extends only in an area axially outside the thread of the screw cap (when it is fully screwed on), in contrast to the toothing elements, which according to the preferred variant and in accordance with the referenced German patent application up to the threaded area of the screw cap, the toothing elements of which are arranged in continuation of a thread.

In addition, an embodiment of the invention is preferred in which the edge of the screw cap springs back axially in the region of its toothing elements or has a recess. When the closure cap is screwed on, such a recess provides a view of the toothing elements of the threaded connector and at the same time defines the position for the application of the fingers on the threaded connector in order to press it together. The recess in the closure cap also has the advantage that a larger area of the threaded connector and, above all, an area of the threaded connector closer to the toothing elements can be gripped by the fingers. This is particularly important because, in principle, the projection or cam, which is offset by 90 ° to the toothing elements, tends to hinder the compression of the toothing areas, since it opposes ovalization of the threaded connector by contacting the inner surface of the screw cap. However, the threaded connector between the cam and the toothing elements has enough space for a radial escape to the outside. Because of the advantages mentioned, this recess would also be expedient in the case of other closures without the mentioned projection, the recess should preferably come close to the screw cap teeth.

As an alternative to the projection on the threaded connector, an inwardly projecting origin could also be provided at a corresponding position on the inside of the screw cap, which, like the toothing elements, is arranged in a continuation of a thread.

Figur 1

einen axialen Schnitt durch einen erfindungsgemäßen Verschluß,

Figur 2

einen Abschnitt senkrecht zur Achse des Verschlusses entsprechend der Linie A-A in Fig. 1,

Figur 3

eine Variante des erfindungsgemäßen Verschlusses mit einem Vorsprung im Inneren der Schraubkappe, und

Figur 4

eine Variante der Schraubkappe mit einer Randaussparung.

Further advantages, features and possible uses of the present invention will become clear from the following description of a preferred embodiment and the associated figures. Show it:

Figure 1

an axial section through a closure according to the invention,

Figure 2

a section perpendicular to the axis of the closure along the line AA in Fig. 1,

Figure 3

a variant of the closure according to the invention with a projection inside the screw cap, and

Figure 4

a variant of the screw cap with an edge recess.

In Figure 1 you can see a tightly hatched lower closure part 6, which has a so-called closure foot 7, which can be bumped into the edge of a circular opening of a sheet metal container, for example. The locking foot 7 is a flexible bellows 4 with a Bellows spout 3 connected, which is a more or less cylindrical part, the upper portion of which is formed by a threaded connector 3a. The free outflow opening of the bellows spout 3 is closed by a seal (not specified) with a tear-off ring.

In Figure 1, the screw cap 1 is slightly wider and hatched with an opposite inclination compared to the lower closure part. The screw cap 1 consists of the so-called cap base 14, one or two fold-out pull-out brackets 15, a cylindrical part 16 with an internal thread and a cylindrical sealing attachment 20 which engages in the threaded connector 3a in a sealing manner, while the cylindrical part 16 is screwed onto the external thread of the threaded connector 3a .

In the lower part of FIG. 1, only the teeth 5 of the threaded connector 3a or the bellows spout 3 can be seen on the left, while the teeth 2 of the screw cap 1 can also be seen on the right. The section plane A-A in FIG. 1 runs exactly through the area of the toothing, so that the teeth or tooth elements 2, 5 in FIG. 2 are very clearly visible. It can be seen that both the teeth 2 and the teeth 5 have an asymmetrical profile with a flat flank and a steep flank, the flat flanks of the teeth 2, 5 sliding slightly on one another, so that due to the elasticity of the plastics from which the Parts 1, 6 exist, the tooth elements 2, 5 jump over one another. In the opposite direction, however, the steep flanks of the teeth 2, 5 engage with one another and thus prevent the cap 1 from being unscrewed from the lower closure part 6 or the threaded connector 3a.

In FIG. 2, the notches 12 denoted in a threaded web 11 can also be seen, which define the teeth 2 between them and which can be seen even more clearly in a perspective view in FIG. 3.

With regard to the parts described so far, the container closure of Figures 1 corresponds to that of Figures 1 and 2 in DE-44 00 993.3. Deviating from that, however, in the present invention, projections 17 are provided diametrically opposite and project radially outward on the lower section of the threaded connector 3. Such a threaded connector 17, which is located on the outside of the threaded connector 3, which is not visible in this illustration, is indicated in dashed lines in FIG. According to the sectional view AA, the two diametrically opposite projections 17 can be seen in an axial top view in FIG. The two projections 17 are offset by 90 ° to the teeth 5 of the threaded connector 3. A radial impression of the threaded connector 3 in the region of the toothings 5 is nevertheless possible, even if the projections 17 rest with their radially outer surface on the inner surface of the screw cap 1. As can be seen, there is enough space between the teeth 5 and the projections 17, in which the deforming threaded connector 3 can escape when the areas with the teeth 5 are pressed radially in order to be able to unscrew the screw cap 1. It should also be noted in this connection that, according to view AA, FIG. 2 shows a left-hand thread, because in the opening direction the steep flanks of the teeth 2, 5 must lie against one another, while in the closing direction the inclined surfaces of the toothings come into engagement with one another, so that when Screwing the lock the flanks of the teeth can slide on each other. For a right-hand thread, the arrows A shown in FIG. 1 should point from bottom to top, corresponding to a view of the cutting surface from below. In this view, however, the projections 17 would not be visible, so that the view from above was chosen here.

Figure 3 shows a screw cap according to a variant of the present invention. This screw cap 1 'in Figure 3 differs from the screw cap 1 in Figures 1 and 2 only in that it has an inwardly projecting projection 17', which, like the teeth 2 also in the extension of a thread, but as close as possible to lower edge of the screw cap is arranged. The position of the projection 17 'corresponds exactly to the position with a closure cap screwed completely onto the threaded connector 3, which position is otherwise assumed by the outwardly facing projection 17 of the threaded connector. In this respect, both projections 17 and 17 'perform essentially the same function, namely that they ensure that after screwing the screw cap 1 onto the threaded connector 3, after a previous deformation, the latter is essentially pushed back into its largely circular cross-sectional shape.

Otherwise, the screw cap 1 is shown in FIG. 3 in the same sectional view as in FIG. 1, but the lower closure part 6 is omitted, so that the view of the threaded inner wall of the screw cap 1 is released. As can be seen, the inwardly projecting thread webs 11 have a trapezoidal profile with a band-like, flat, thread surface 13. The lower end section of the thread web 11 has a series of notches 12 which have already been described in the radial sectional view in connection with FIG which define the teeth 2 in the form of the areas of the thread web 11 which have remained between the notches 12. The axial length h of the thread web 11 and thus the minimum width of the teeth 2, which with corresponding teeth 5 of the lower closure part 6 engage, is at least 0.5 mm, but should preferably be more than 1 mm. As can be seen, the screw cap 1 has no bulge, extension or other additional space requirement, because ultimately the teeth 2 are only defined by recessed areas 12 in a thread web 11 which is already present. On the corresponding threaded connector 3a or on the cylindrical bellows spout 3, of which the threaded connector 3a forms a section, the teeth 5 are provided on the axial height corresponding to the teeth 2, which engage with the teeth 2. The thread of the threaded connector 3a can easily extend into the area of these teeth 5, ie the teeth 5 could also easily define the lowest section of the thread of the threaded connector 3a.

Although the teeth 2 and the projection 17 'are drawn in at almost the same axial height in FIG. 3, the teeth 2 in FIG. 3 should preferably lie axially further up, while the projection 17' is arranged as close as possible to the lower edge 10 of the screw cap 1 should.

In a variant shown in FIG. 4, the lower edge 10 of the screw cap 1 has an axially recessed recess 19 in the region of the toothings 2. This recess 19 provides a view of the toothing 5 of the threaded connector 3 when the screw cap 1 is firmly screwed onto the threaded connector 3, since the toothings 2 and 5 engage in one another and are therefore in the same area as the axial recesses 19 one can also grasp the toothed area of the threaded connector more easily with the fingers of one hand and, above all, can exert the pressure force relatively close to the engagement with the teeth 2 of the screw cap toothing. This makes it relatively safe and without too much effort to compress the threaded connector 3 in the area of its teeth 5 to such an extent that they come out of engagement with the teeth 2 of the screw cap.

Reference list

1,

1 'screw cap

2nd

Gearing

3rd

Bellows pourer

3a

Threaded connector

4th

bellows

5

Gearing

6

Lower part of the closure

7

Locking foot

10th

edge

11

Thread bridge

12th

Notches

13

Thread surface

14

Cap bottom

15

Pull-out bracket

16

cylindrical part

17th

Sealing approach

17,

17 'projections

19th

Recess

Claims (10)

Container closure with a threaded connector (3) provided on a container and a screw cap (1) which can be screwed thereon, at least the threaded connector (3) consisting of a plastic material which can be deformed by finger pressure and with toothing elements (2, 5) in the area of the threaded connector (3) and the screw cap (1) are provided, which are in engagement with one another when the screw cap (1) is completely screwed in and only allow the screw cap (1) to be unscrewed if either the threaded connector (3) and / or the screw cap (1) is in the region of the Gear elements (2, 5) are deformed in order to disengage the gear elements (2, 5), characterized in that on the threaded connector (3) or on the screw cap (1) are offset in the circumferential direction to the toothed elements (5) of the threaded connector ( 3) or the screw cap at least one radial projection (17, 17 ') is provided between the threaded connector (3) and the screw cap (1). Screw closure according to claim 1, characterized in that two projections are provided diametrically opposite one another. Screw closure according to one of claims 1 or 2, characterized in that the radial distance of the outermost surface of the projection (17) from the axis (18) of the screw closure corresponds to the inner radius of the screw cap (1) axially outside the thread area. Container closure according to one of claims 1 to 3, characterized in that the axial position of the projection (17) is selected such that, when the cap (1) is completely screwed on, it is still inside the screw cap (1) outside the threaded area. Container closure according to one of claims 1 to 4, characterized in that toothed elements (5) are provided in pairs and diametrically opposite one another on the threaded connector (3), while two projections (17) to the toothed elements (5) are offset in the circumferential direction by 90 ° and also diametrically are arranged opposite one another. Container closure according to one of claims 1 to 5, characterized in that the projection (17) in the axial direction is a greater distance from the bottom of the screw cap has as the interlocking gears (2, 5). Container closure according to one of claims 1 to 6, characterized in that the projection (17 ') is provided projecting radially inwards on the screw cap (1) near the lower edge (10) thereof. Container closure according to one of claims 1 to 6, characterized in that the projection (17) is provided projecting radially outwards on the threaded connector (3). Container closure according to one of claims 1 to 8, characterized in that the edge defining the open end of the screw cap (1) has an axially recessed recess (19) in the region of the toothing elements of the screw cap. Container closure according to claim 9, characterized in that the recess extends to just below a toothed threaded area of the screw cap.

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