EP1399366B1 - Closing device with a piercing element - Google Patents

Abstract

A closing device arranged above a pierceable point of a closed container including a lower part with a cylindrical discharge nozzle, a screw cover and a piercing element. The piercing element, which is open on both sides, is displaced downwards in an axial direction in a screw-like manner in a screw cover in the lower part of the closing device. The piercing element has two cutting elements offset at an angle which produce a continuous, interconnected cutting line, and a displacing element which shifts a partially cut-out tab of the container from a region of the discharge nozzle.

Description

The present invention relates to a closure device made of plastic, which is attachable via a pierceable body of a closed container and consists of a bung-shaped lower part with a cylindrical spout, which is connected to the container or connectable, and a screw cap which can be pushed onto the lower part, and a cylindrical piercer, which is open on both sides in the axial direction and is displaceably mounted in the lower part, wherein in the screw cap means are provided which move the piercer helically downward during the first unscrewing movement of the screw cap.

Closure devices made of plastic consisting of the three parts, as described above, namely a bung-shaped base with cylindrical spout, a movable therein cylindrical Durchstosser and a screw cap, which has means to move the piercer, are known in various embodiments. Such closure devices are on Soft packaging containers attached. The containers consist of multilayer films, which usually have one or more paper or cardboard layers, one or more plastic film layers and at least one barrier layer, for example of aluminum. In the area of the closure devices to be applied, the packages have correspondingly pre-punched puncture points. Usually, according to the piercing device of the closure device, usually only the innermost, compact plastic film layer and the aluminum layer have to be severed.

In most known embodiments, the piercer is guided so that the piercer exerts only a translational movement toward the interior of the package. For example, EP-A-0'328'652 (Toppan Printing Co. Ltd.) discloses a solution in which a slide-like helix is centrally mounted on an inner wall in the screw cap, while the piercer has a similar counter-rotating thread while at the same time the piercing is provided with cams, which prevent rotation relative to Ausgussspund. A virtually identical solution is also known from WO 99/62776 (Crown Cork and Seal Technologies Corp.). Also from GB-A-2241224 a closure device is known with a bung-shaped spout, in which a piercer with guide cam runs, wherein the guide cam in axial engage extending grooves, while at the same time the piercer has an internal thread which cooperates with a central annular wall in the screw cap, wherein the central wall has an external thread. At the same time there is a threaded connection between the screw cap and the spout.

This latter solution according to GB-A-2241224 does not work with a puncture site in the package but the pouring spout is already welded from the inside to the packaging inner wall and an additional film is mounted on the inside of the spout of the spout. Such a sealing film may have any properties that differ from the actual packaging. Accordingly, the shape of the puncture can be practically arbitrary, as for example in the solution according to FIG. 1 of that publication, or several perforation teeth can also be provided on the circumference of the puncture. Completely analogously, a piercer is also shown in the embodiment according to EP-A-0'328'652, which has a plurality of perforation teeth at the lower edge. The same applies to the also already mentioned WO 99/62776.

In contrast to the aforementioned protective rights, WO 95/05996 (International Paper Company) shows a closure device in which the piercer is not only a clean performs translatory movement but a screwing. The piercer correspondingly has an external thread, which is guided engaging into an internal thread in the pouring spout. The piercer can be displaced by means of entrainment in the screw cap in a corresponding screwing. If the screw cap is unscrewed, the piercer simultaneously moves downward in a screwing movement into the container to be opened. Completely analogous to the previously known solutions, the piercer also has a multiplicity of perforation teeth along its lower edge.

Virtually all closure devices of the type of interest available on the market today have given rise to great problems. While the first solutions, which were not documented here, worked practically without perforation teeth and where the wall of the container was destroyed somewhere, it was believed that the perforation teeth could be used to tackle the problem. This is not true. One of the main reasons is that all solutions require a lot of effort when opening. Virtually all solutions simultaneously perforate many parts of the film over the entire circumference. If the teeth were located exactly in those places that are vertically above the pre-separated film, so would probably be such a solution. However, this would be an accurate to a tenth of a millimeter attachment of the Require closure device on the container. But this is simply impossible. Accordingly, the teeth dig into areas of the package, which are not pre-punched. Not only does this require much more force, but at the same time there is no longer any perforation of the film, but a pure pulling movement takes place on the film. While films tend to be sensitive to perforations, most films are extremely resistant to tensile forces.

In the embodiment according to WO 95/05996 it was not recognized that in the solution shown here essentially a cutting effect is achieved instead of a piercing effect. Accordingly, the concept with a multiplicity of perforation teeth is in itself contradictory. In addition, even with a small angle of rotation, the entire inner area is cut out of the packaging and falls into the contents of the container. This is not only undesirable and unhygienic, but also leads to the fact that during the pouring the loose part repeatedly reaches the spout area and leads to uncontrollable pouring properties.

It is therefore the object of the present invention to improve a closure device of the type mentioned in such a way that easy opening is possible, in which while the other disadvantages described above can be avoided at the same time.

This object is achieved by a closure device which has the features of claim 1.

When choosing the offset angle α is ensured at a size of less than 180 °, that no complete separation of the packaging area can be done, while the choice of the offset angle by more than 100 ° ensures that at the moment because the displacement element is effective, more as half the circumference is severed and thus the already severed part is folded away. The latter would already be given, even if the displacement angle would be less than 100 °, but on the one hand, the danger would be great that the displacement element not only pushes the already separated area to the side but would also bring the not yet severed area to tearing , Finally, however, even with a displacement angle of less than 100 °, the open spout area would be restricted too much.

Further advantageous embodiments of the subject invention will become apparent from the dependent claims and their meaning and effect is explained in the following description with reference to the accompanying drawings.

Figur 1

einen Vertikalschnitt durch die Verschlussvorrichtung im montierten Zustand auf einem Behältnis vor der erstmaligen Öffnung und

Figur 2

dieselbe Verschlussvorrichtung nach der erstmaligen Öffnung mit abgeschraubter Schraubkappe wiederum im montierten Zustand in einem diametralen Vertikalschnitt.

Figur 3

zeigt den Durchstosser in der Herstellungslage einstückig verbunden mit dem Unterteil wiederum als diametralen Vertikalschnitt, während

Figur 4

die Verschlussvorrichtung im montierten Zustand in der Gebrauchslage zeigt, wobei lediglich die Verpackung teilweise geschnitten dargestellt ist.

Figur 5 und Figur 6

stellen schematische Schneid- und Biegepläne dar für zwei verschiedene Versetzungswinkel α.

In the drawing, a preferred embodiment of the subject invention is shown. It shows:

FIG. 1

a vertical section through the closure device in the assembled state on a container before the first opening and

FIG. 2

the same closure device after the first opening with unscrewed screw cap again in the mounted state in a diametrical vertical section.

FIG. 3

shows the piercer in the manufacturing position integrally connected to the lower part in turn as a diametrical vertical section, while

FIG. 4

shows the closure device in the assembled state in the position of use, with only the packaging is shown partially cut.

FIG. 5 and FIG. 6

represent schematic cutting and bending plans for two different displacement angle α.

Although the invention is concerned essentially only with the configuration of the piercer, the entire structure of the closure device 1 is shown consisting of three parts for a better understanding. These are a lower part 2, which is adhesively attached to a container B, a screw-mounted therein pierced body 3 and a Lower part 2 cross-screw 4. The lower part 2 has a cylindrical spout 20 which merges terminally into a lower flange 21 and an internal thread 22 and an external thread 23 has. The flange 21 serves for the adhesive connection with the container B. This container consists of a multilayer, made of films soft pack, wherein the multilayer film has a so-called pre-punching V, which penetrates one or more layers at least partially, thus defining a desired opening. Consequently, in order to open the container B, the multilayer film in the region of the pre-punching V must still be severed completely. The flange 21 of the lower part 2 may be welded or glued on the multilayer film of the container B. The pre-punch V defines a circular area which has to lie within the opening of the cylindrical spout 20. The diameter of the pre-punching V is smaller than the diameter of the pouring spout 20 by a few percent. On the other hand, the diameter of the pre-punching V corresponds almost exactly to the diameter of the piercer 3 or the circular path which the cutting elements of the piercer define during their movement. The internal thread 22 of the cylindrical spout 20 is a coarse thread. This means that on the one hand the thread height is relatively large and the thread has a high pitch. As a result, even by a rotation of about 360 ° or less, the piercer 3 is replaced by its original mounting position, as in FIG 1, moved into the lower use position according to FIG. In contrast, the external thread 23 is realized as a so-called fine thread. Accordingly, the thread 23 has only a small height of the thread flanks and the pitch of the thread is flat. To unscrew the screw cap 4, this must therefore make several turns.

The actuation of the penetrator 3 is effected by means of the screw cap 4. The screw cap 4 has a cover surface 40, on which a circumferential casing wall 41 is adjacent. The jacket wall 41 has an internal thread 42, which is designed as a fine thread, matching the external thread 23 of the cylindrical spout. At the bottom of the top surface 40 a concentric with the jacket wall 41 extending annular wall 43 is formed. At this concentric annular wall 43, which has a diameter which is smaller than the inner diameter of the piercer, means are formed in the form of drivers 44. Upon rotation of the screw cap 4, the drivers 44 drive the piercer 3 in an opposite direction. While the screw cap 4 moves upward, the piercer is moved downwards, because the threads between the screw cap 4 and lower part 2 are oriented in opposite directions to the direction of rotation of the thread between piercer 3 and lower part 2. At the bottom of the shell wall 41 is via predetermined breaking point bridges 46 a guarantee band 45 molded. This is held by retaining cam 24 in the secured position and the guarantee band 45th remains here after the first opening, as can be seen in Figure 2.

The piercer 3, which is advantageously made in one piece with the lower part, as shown in FIG. 3, essentially consists of a cylindrical annular wall part 31 with an external thread 32 which, in turn, is designed as a coarse thread, matching the internal thread 22 of the lower part 2. At this annular wall part 31 are formed at least two cutting elements 33 and at least one displacement element 34,35. The displacement element 34 can be combined with the cutting element 33 or, as can be seen in FIGS. 2 to 4, designed as a separate element 35. In the sectional drawings according to FIGS. 1 to 3, only one cutting element 33 can be seen in each case. Only in the side view according to FIG. 4 are both cutting elements 33 visible. The cutting elements 33, which have approximately a triangular shape, open into a terminal perforation tooth 36. An arrow D indicates in each case the direction of rotation of the piercer. At the front edge of the direction of rotation, a cutting edge 37 is formed directly on the perforation tooth 36. The cutting edge 37 is here in the preferred embodiment in a displacement edge 38, which thus forms here the displacement element 34 and thus part of the cutting element 33 is. On the inner surface of the cutting element 33 above the cutting edge 37 is a Mitnehmerverdickung 39 integrally formed, on which a driver 44 during the initial Abschraubbewegung the screw cap 4 rests and thus the Durchstosser 3 in a screwing motion. The solution with the displacement edge 38 is merely optional. As already mentioned, and also realized here, an additional separate displacement element 35 may be present. The displacement element 35 is made shorter in the axial direction of the penetrator 3 than the cutting element 33. Accordingly, the displacement element 35 comes into contact with the film of the container B only when the two cutting elements 33 have formed at least approximately a continuous cutting line. The separate displacement element 35 otherwise has approximately the shape of the cutting elements 33, but is truncated-edged and has no perforation tooth but runs in a rounded arc.

With reference to Figures 5 and 6, the operation of the inventive closure device is explained below. The two cutting elements 33 are arranged trailing one another at an offset angle α. In the starting position before the first opening of the closure device, the two perforation teeth 36 of the two cutting elements 33 are located on the positions a 'and b'. After a certain feed angle β, the two perforation teeth 36 touch the foil of the container to be cut at the points A and B. With reference to FIGS Direction of rotation D runs the perforation tooth of a cutting element before the perforation tooth of the second cutting element by an offset angle α. Upon further rotation in direction D, the perforating teeth 36 pierce the film and subsequently sever the film, with one cutting element passing the cutting path from point A to point B while the other cutting element from point B to point C applies a cutting line. As soon as the piercer has thus been rotated by the offset angle α, a coherent cutting line of 2α results, which extends from point A to point C. In this position, at least approximately completely, the cutting edge 37 has penetrated through the film of the container inside and from point C now acts on the one hand the displacement edge 38 and / or the displacement element 35. The displacement edge now acts from the point C, while the displacement element 35 in the area VB which is relatively close to the pre-punching V in the not yet severed area. Like a flap now, the cut-free area is pushed down into the container. Here, the pre-punching V practically serves as a bending line. Clearly, this situation can be seen for example in FIG. Depending on the choice of the offset angle α is the remaining, not severed region of the pre-punching V larger or smaller. Theoretically, the feed angle α must be at least 90 °, but this is practically not enough and the actual minimum size of the Displacement angle α must be greater than 100 °. Of course, the offset angle α must also be less than 180 ° to ensure that the cut line is not circumferential and consequently an entire roundel is cut out of the film which could fall into the container. Realistically, the maximum displacement angle α should be about 170 °. The solutions shown in Figures 5 and 6 correspond to realistic information. If you work with a separate displacement element 35, the displacement angle α may be rather small, because in this case, the displacement element can already press on the film just before the front in the direction of rotation cutting element has reached the point C, whereby the film is pressed slightly downwards and thus a slightly longer contiguous cutting line is formed as the theoretical cutting line.

In comparison to the previously known punctures with a multiplicity of perforating teeth, the perforation takes place here only at two points. This has the advantage that the required power is lower. At the same time there is also a real cutting motion here. Namely, the cutting edge 37 performs both a movement component perpendicular to the cutting line and a component in the direction of the cutting line. But because the pre-punching V also relatively close to the relatively rigid connection of the film with the flange 21 of the lower part 2 runs, there is a certain shearing force.

Of course, the steepness of the coarse thread between the piercer 3 and the lower part 2 must be aligned with the geometry of the cutting elements. The purely vertical length of the cutting edge 37 must be equal to the thread pitch, which corresponds to the angle α. The latter applies in particular when the displacement element is combined with the cutting element.

List of reference numbers

1

closure device

2

lower part

3

piercing

4

screw cap

20

Spout cylindrical

21

flange

22

inner thread

23

external thread

24

Retaining cams

31

Ring wall part cylindrical

32

external thread

33

cutting elements

34

displacement element

35

Separate displacement element

36

Perforierungszahn

37

cutting edge

38

displacement edge

39

Mitnehmerverdickung

40

cover surface

41

shell wall

42

inner thread

43

Concentric ring wall

44

takeaway

45

guarantee strip

46

Weakened bridges

B

container

V

precut

Claims (8)

1. A closure device (1) of plastic which may be attached above a piercable location of a closed receptacle (B) and which consists of a bung-like lower part (2) with a cylindrical pouring spout (20) which is connected or connectable to the receptacle, and of a screw cap (4) which may be screwed onto the lower part (2), as well as of a cylindrical piercing element (3) which in the axial direction is open on both sides and which is displaceably mounted in the lower part, wherein in the screw cap (4) there are present means (44) which during the screwing-off movement of the screw cap for the first time move the piercing element (3) helically downwards,
   characterised in that the piercing element (3) is equipped with at least two cutting elements (33) which are arranged running after one another by an offset angle (α) of less than 180° and more than 100° so that after a rotation of the piercing element by the offset angle a continuous cutting line of 2α has arisen, and that now a displacing element (34, 35, 38) acts in the non-separated region, which pushes the partly cut-out lobe of the receptacle out of the region of the pour-out spout (20).
2. A closure device according to claim 1, characterised in that the displacing element is combined with the leading cutting element (33), into a single element (34, 38).
3. A closure device according to claim 2, characterised in that the leading cutting element (33) has a cutting edge (37) which merges into a displacing edge (38) acting as a displacing element, wherein the cutting element (37) is so long that with the screwing movement after one rotation (D) of the piercing element (3) by at least approximately the offset angle α the displacing edge (38) pushes the non-separated region of the receptacle (B) out of the region of the pour-out spout (20).
4. A closure device according to claim 1, characterised in that in the rotational direction of the piercing element (3) there is present a displacing element (35) which is separated from the cutting element and which runs ahead of the leading cutting element (33).
5. A closure device according to claim 4, characterised in that in the two cutting elements (33) and the displacing element (35) are integrally connected with the piercing element (3).
6. A closure device according to claim 1, characterised in that the two cutting elements (33) and the displacing element (34) are offset concentrically to the outer wall of the cylindrical piercing element (3) towards the centre approximately by the wall thickness of the annular wall part (31).
7. A closure device according to claim 1, characterised in that the piercing element (3) including the cutting elements (33) has an axial length which corresponds maximally to the axial length of the cylindrical pouring spout (20).
8. A closure element according to claim 4, characterised in that the displacing element (35) is shorter than the two cutting elements (33) by the axial distance which corresponds to the axial movement path which the two cutting elements (33) have travelled with a rotation of the piercing element (3) by the offset angle α.

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