CONTAINER CLOSURE

Description

Field of the invention

[0001] The invention relates to a container closure according to the preamble of claim 1. State of the art

[0002] Prior art in the field of plastic closure caps includes container closures which have a lid hinged to a retaining ring, thus ensuring the lid is securely attached to the container. This hinged lid function is particularly important for food containers, as the lid does not need to be stored separately and therefore cannot become soiled or lost.

[0003] The lid can be pivoted around the hinge from a closed position to an oven position. It is known that the lid can be locked in the open position against the retaining ring. For this purpose, a first projection formed on the lid can engage with a second projection formed on the retaining ring in the open position of the lid. This prevents the lid from unintentionally folding down into the flow of the contents during use of the container.

[0004] After using the container, the locking mechanism can be released and the lid can be pivoted from the open position to the closed position to close the pouring opening.

[0005] However, in order for the locking mechanism between the two extensions to engage, the lid must be swivelled by a large range of approximately 200 degrees, which is inconvenient for the user.

[0006] US patent 2990077A discloses a plastic hinged closure with a lid suitable for closing many containers. The lid can pivot between an open and a closed position and has a sealing ring on its underside, which, in the closed position, protrudes into the container neck. Object of the invention

[0007] The disadvantages of the described prior art give rise to the objective of improving a container closure with a pivoting lid. In particular, the invention aims to improve the user-friendliness of the container closure for both the end consumer and the industrial bottler. Description

[0008] The problem posed is solved in a container closure by the features listed in the characterizing section of claim 1. Further developments and / or advantageous embodiments are the subject of the dependent claims.

[0009] The invention is preferably characterized in that the sealing element has a height and a retaining tongue, such that the height of the sealing element is greater in the area of ​​the joint than on the rest of the circumference of the sealing element, and that the lid can be pivoted into a second open position in which the retaining tongue can rest against the open edge of the pouring opening or the upper edge of the retaining ring. The user can therefore individually choose between two open positions of the lid. Depending on the fill level of the container, the first or the second open position may be advantageous. With a small fill level, the container must be tilted more to pour. In this case, the lid in the first open position, in which it is more open, is advantageous because the lid is further away from the pouring stream.If the container is still full, it is advantageous when pouring if the lid is in the second position, as the lid in this less open position can serve as a spillage guard.

[0010] It has proven advantageous for the retaining tongue to have a tip that corresponds to the highest point of the sealing element. The tongue-like shape with its raised tip allows the sealing element to be easily removed from and inserted into the pouring opening when opening or closing. It is further beneficial if the retaining tongue can be elastically deformed when pressed against the open edge of the pouring opening.

[0011] The increase in height on both sides of the tongue tip is advantageously stepless. This allows the retaining tongue to slide in and out of the pouring opening without getting caught on the open edge of the pouring opening.

[0012] It has proven advantageous if the retaining tongue has a length along the circumference of the sealing element defined such that the retaining tongue forms an opening angle with the center of the lid of between 90 and 40 degrees, preferably between 80 and 50 degrees, and particularly preferably between 70 and 60 degrees. The required length of the retaining tongue ensures that it is sufficiently stable to prevent it from yielding in the second open position. At the same time, the retaining tongue is sufficiently flexible to allow it to move in and out of the pouring opening with minimal effort when the lid is pivoted around the hinge.

[0013] The invention is preferably characterized in that the retaining ring and the lid, in the first open position, enclose a first angle of inclination between 180 and 220 degrees, and preferably between 190 and 210 degrees, and that, in the second open position, the retaining ring and the lid enclose a second angle of inclination between 70 and 90 degrees, and preferably between 75 and 95 degrees. In the two open positions, the lid can be fixed at angles of inclination that differ significantly from one another. This allows the hinged lid to be adjusted to the current fill level of the container. This significantly simplifies the handling of the container, particularly when pouring.

[0014] In a particularly preferred embodiment of the invention, the sealing element is a lid surface with a shoulder, offset towards the retaining ring. The shoulder, due to the inward offset of the lid surface, forms a stable sealing surface which remains stable under radial contact pressure from the inner wall of the container neck and forms a defined sealing surface. This allows the pouring opening to be sealed particularly tightly by the lid.

[0015] The sealing element can also be a sealing ring oriented towards the retaining ring. This design is suitable for applications with less stringent requirements for the tightness of the container closure.

[0016] In a further particularly preferred embodiment of the invention, at least one drive element is formed on the lid in the direction of the retaining ring, which is received in a corresponding recess provided on the retaining ring when the lid is in the closed position. The interaction of the drive element with the recess ensures reliable protection against rotation of the lid relative to the retaining ring. This reliably protects the tamper lugs from unintentional breakage during the initial rotational connection of the container closure to the container.

[0017] Advantageously, the drive element has a ramped shape with a stepped side and a sloping side. This sawtooth-like design of the drive element ensures that the anti-rotation device acts in the direction in which the container cap is first opened. If it is rotated in the opposite direction, the locking tabs break.

[0018] In a preferred embodiment of the invention, the first extension is realized by a groove formed on the retaining ring, and the second extension is realized by a projecting lid rim, which locks into the groove in the first open position. The first and second extensions ensure secure locking in the first open position. Furthermore, the extensions can be easily molded using injection molding and are simple to demold. It is preferred that the retaining bands are pre-tensioned in the second open position. This allows the lid to be held securely in the groove at the lid rim without wobbling, preventing the lid from folding back from the first open position.

[0019] In a further embodiment of the invention, the first extension has a slot with a recess, the second extension has a crossbar, and the crossbar engages in the recess in the first open position. The crossbar rests against the recess when the first extension is engaged in the second extension. Since the crossbar must be pressed over the recess when engaging and disengaging, the cover is held particularly securely in the first open position in this embodiment.

[0020] In a preferred embodiment, the joint is formed by a first and a second ligament, and the first extension is located between the first and second ligaments. This improves the stability of the joint, and the ligaments can be pre-tensioned in the first and / or second open position.

[0021] It is advantageous if, before the container is opened for the first time, at least one tearable tamper-evident strip connects the upper edge of the retaining ring to the lid. This makes it immediately apparent whether the container is sealed or has already been opened.

[0022] In a further embodiment of the invention, the container closure can be bounced onto the neck of the container. The container closure can therefore be mechanically and thus quickly attached to the bottle neck on a conveyor belt.

[0023] Because the container closure is manufactured in one piece, it can be mass-produced quickly and cost-effectively using an injection mold.

[0024] Advantageously, the container closure is made of polypropylene. This allows the retaining tongue to be elastically deformed when pivoting from the second open position to the closed position.

[0025] In a particularly preferred embodiment of the invention, the retaining ring has slots distributed around its circumference, each with an upper edge and a lower edge. The upper edge is formed by a circular arc-shaped section of the retaining ring, and the lower edge is formed by a wall section inclined radially inwards. The lower edge of each slot forms projections, thereby creating engagement means for a positive-locking engagement with an annular projection on the outside of the container neck. Since the engagement means, in the form of the inwardly inclined wall sections, are not present on the entire circumference of the retaining ring, and since the slots are also present, the shape of which further reduces material usage, the plastic material requirement can be significantly reduced by up to 5%.Furthermore, the inward wall section is immovable in the radial direction, thus holding the retaining ring against the annular projection and allowing it to be pulled over the projection only when the retaining ring is stretched along its circumference. The retaining ring is held so firmly against the annular projection by the wall sections that the predetermined breaking points reliably tear before the wall sections' retention is overcome. However, the wall sections are flexible and movable in the radial outward direction. This allows the wall sections to be demolded from the injection mold with minimal effort. For the same reason, the application force required to snap the cap on is significantly reduced compared to prior art. Stretching of the tamper-evident ring, which could lead to permanent damage to the cap, is largely prevented during demolding and snapping. The wall sections therefore act like barbs.

[0026] Further advantages and features will become apparent from the following description of an exemplary embodiment of the invention with reference to the schematic diagrams. These are shown in a representation not to scale: Figure 1: a container closure in an open position in a side view; Figure 2: the container closure made of Figure 1 in a sectional view along the drawing plane, which passes through the axis of rotation; Figure 3: a side view of the container closure in a first open position; Figure 4: the container closure made of Figure 3 in a sectional view along the drawing plane, which passes through the axis of rotation; Figure 5: a top view of the container closure in the first open position; Figure 6: a perspective view of the container closure from Figure 3Figure 7: a perspective view of the container closure in a further embodiment; Figure 8: a side view of the container closure in a second open position; and Figure 9: the container closure made of Figure 8 in a sectional view along the drawing plane, which passes through the axis of rotation; Figure 10: another embodiment of the container closure in a side view; Figure 11: the embodiment from Figure 8 in a sectional view; Figure 12: a perspective view of the container closure made of Figures 10 and 11 in a first open position; Figure 13: a perspective view of the container closure from Figures 10 and 11 in a second open position; Figure 14: a detailed view of the retaining ring in a further embodiment and Figure 15: a sectional view of the retaining ring made of Figure 14 with visualized tilt angles.

[0027] The Figures 1 to 13Figure 11 shows a container closure, collectively designated by reference numeral 11, which serves to close the pouring opening of a container. The closure cap 11 has a retaining ring 13 and a lid 15, which are connected by a hinge 17. The hinge can be implemented by a first and a second hinge band 17a, 17b. The hinge is preferably a film or tape hinge. The lid 15 can be pivoted about the hinge 17 from a closed position. The closed position is defined in the Figures 1, 2 , 10 and 11 shown. In the Figures 3 to 6 and 12 A first open position is shown, into which the lid can be pivoted. In the first open position, the retaining ring 13 and the lid 15 enclose a first tilt angle 19 of approximately 200 degrees.

[0028] To enable the lid 15 to be fixed in the first open position, a first extension 21 is formed on the retaining ring 13 and a second extension 23 is formed on the lid 15. In the first open position, the first and second extensions 21, 23 interlock. The retaining ring 13 has an upper rim 35 and a lower rim 36.

[0029] A sealing element 25 is formed on the inside of the lid 15. In the Figures 1 to 9The sealing element is designed as a sealing ring 25. In the closed position, the sealing ring 25 projects into the pouring opening 27 of a container 29. The container 29 includes a neck 30 on which the pouring opening 27 is provided. To ensure that the outer surface of the sealing ring 25 and the inner surface of the pouring opening 27 seal together, the sealing ring 25 can be conical. In this case, the sealing ring 25 is designed as a "cone sealer". An interference fit can also be provided between the sealing ring 25 and the pouring opening 27 to reliably seal the pouring opening 27.

[0030] As in the Figures 1 to 5As shown, in a first embodiment, the first extension is realized by a groove 21. The groove 21 is formed between the first and second hinge bands 17a, 17b on the retaining ring 13. The second extension is a projecting lid rim 23. When the lid 15 is pivoted into the first open position, the lid rim 23 can be locked into the groove 21. The lid 15 is held in the first open position and therefore cannot unintentionally protrude or fold into the flow of liquid when pouring from the container 29.

[0031] In a second embodiment according to the Figure 7The first extension forms a gap 22. The gap 22 is oriented in the direction of the axis of rotation 31. Furthermore, a recess 32 is provided in the gap 22. The second extension 23 has a crossbar 33. When the cover 15 is opened into the first open position, the second extension 23 is pressed into the gap 22. The crossbar 33 engages in the gap 22 below the recess 32, thus holding the cover 15 in the first open position. The opened cover 15 therefore does not fall shut on its own, but can only be moved from the first open position by applying force.

[0032] Before the lid 15 is opened for the first time, a plurality of tamper bars 37 connect the retaining ring 13 to the lid 15. The tamper bars 37 are arranged around the circumference of the upper edge 35. When the lid 15 is first pivoted, the tamper bars are torn. The torn tamper bars 37 indicate, in the closed position, whether the lid 15 has already been opened or not.

[0033] The lid 15 can also be pivoted into a second open position. To hold the lid 15 in the second open position, a retaining tongue 39 is formed on the sealing ring 25. The retaining tongue 39 is achieved by the sealing ring 25 being higher in the area of ​​the hinge 17 than on the rest of its circumference. The highest point of the retaining tongue 39 is to be designated as the retaining tongue 41. Preferably, the increase in height on both sides of the tongue tip 41 is continuous, homogeneous, and symmetrical. The length of the retaining tongue is defined by its opening angle 45 with the center point 43 of the lid. The opening angle is preferably 75 degrees.

[0034] In the second open position, the retaining tongue 39 rests against the pouring opening 27, thus preventing the lid 15 from closing unintentionally. If the upper edge 35 of the retaining ring extends beyond the open edge 47 of the pouring opening 27, the retaining tongue 39 rests on the upper edge 35.

[0035] In the second open position, the retaining ring 13 and the lid 15 enclose a second angle of inclination 49 of approximately 80 degrees. Preferably, the first and second hinge bands 17a, 17b are pre-tensioned in the second open position, thereby drawing the retaining tongue 39 against the open edge 47. This prevents the lid 15 from wobbling in the second open position. When the lid 15 is closed and opened, the retaining tongue 39 and / or the open edge 47 are elastically deformed. This allows the sealing ring 25 to be fully received in the pouring opening 27 in the closed position.

[0036] In the Figures 10 to 13The sealing element is an inwardly offset cover surface 25. This offset creates a shoulder 51 at the transition to the rest of the cover 15. The cover surface 25 projects into the pouring opening 27, with the shoulder 51 resting against the inner wall of the pouring opening in the closed position. The shoulder 51 is more stable than a sealing ring and can therefore be pressed more precisely against the inner wall. This improves the sealing properties of the cover 15.

[0037] The cover 15 has an outer ring 53 which is aligned with the retaining ring 13. The outer ring 53 is connected to the retaining ring 13 by the guarantee lugs 37. In the Figures 10 , 12 and 13It is shown that drive elements 55 are formed on the open edge of the outer ring 53. The drive elements 55 are particularly effective when they are arranged opposite the joint 17. The drive elements 55 engage in or project into recesses 57 provided on the retaining ring 13. This applies to the closed position and is shown in the Figure 10As shown. Advantageously, the recess 57 essentially has the negative shape of the drive element 55. Preferably, the drive element 55 has a ramped or sawtooth shape. It therefore has a stepped side 59 and an inclined side 61. This reliably prevents rotation of the lid 15 relative to the retaining ring 13, since when torque is applied, the stepped side 59 abuts the recess 57. When the container closure 11 is first attached to the container neck 30 after filling the container 29 by a rotational movement or is forced onto it by an axial movement, the drive elements 55 prevent the tamper lugs 37 from being unintentionally damaged or even torn off by rotation. The drive elements 55 advantageously act in the direction of rotation of the impact of the container closure 11.The guarantee lugs 37 necessitate a gap 63 between the outer ring 53 and the retaining ring 13 in the closed position. This gap 63 is also present between the drive elements 55 and the retaining ring 13. This ensures that the drive elements 55 do not impede the opening of the cover 15.

[0038] The lid 15 of the cap 11 can be pivoted into a first and a second open position, locking into place in both positions. This allows the user to choose between two open positions when pouring. With a nearly full container, it can be advantageous to choose the second open position, as the lid can then act as a spill guard. Conversely, if the container is nearly empty, it is more practical to choose the first open position, as the container needs to be tilted more sharply for emptying. In the first open position, the lid 15 is less obstructive when tilting the container 29 than when it is in the second open position.

[0039] To hold the retaining ring 13 in the axial direction, projections 65 are formed on the inside of the retaining ring 13. The projections 65 can be described as follows in the figure description. Figures 14 and 15This embodiment of the projections 65 is the subject of Swiss patent applications numbered 01467 / 19 and 01695 / 19, the priorities of which have been claimed and whose disclosures are hereby incorporated into the present patent application. Slots 67 are provided on the retaining ring 13, distributed around its circumference. Each slot 67 has an upper edge 69 and a lower edge 71. The upper edge 69 is formed by a circular arc section of the retaining ring 13. The lower edge 71 corresponds to the free edge of a wall section 73 inclined inwards in a radial direction. Due to the inward inclination of the wall section 73, the lower edge 71 has a smaller radius than the retaining ring 13 and can therefore abut a support (annular projection 66) of the container neck 30 when the lid 15 is folded away from the retaining ring 13.The abutment is formed by the annular projection 66, which is located on the outside of the container neck 30. When the lid 15 is opened, the lower edge 71 engages the projection 66 in a form-fitting manner, thereby reliably holding the retaining ring 13 against the annular projection 66 even under high axial forces. As a result, the locking lugs 37 reliably break when the lid 15 is opened, preventing the retaining ring 13 from unintentionally detaching from the container neck.

[0040] Each wall section 71 has a first subsection 75 and two second subsections 77. The first subsection 75 represents an inwardly folded shell section and is preferably flat. The second subsections 77 adjoin the inwardly facing sides of the first subsection 75 and connect it to the retaining ring 13. The second subsections 77 can be curved or flat and are inclined inwards towards each other. The lower edge 71 of the slot 67 corresponds to the free edges of the first subsection 75 and the second subsections 77 and lies in a plane 79, which is Figure 15The plane 79 is preferably oriented perpendicular to the axis of rotation 31 of the container neck 30. These described design features of the wall section 73 have the advantage that the entire lower edge 71 of the wall section 73 can rest against the annular projection 66 and does not yield under an upward axial tensile force, acting like a barb. This ensures that the retaining ring 13 is permanently held on the projection 66 or can only be removed from the projection 66 by destroying it. The provision of the second sections 77 prevents inward movement of the first section 75 in a radial direction. However, outward movement of the first section 75 in a radial direction is possible. This movement is flexible, and the wall section 73 returns to its inwardly inclined initial position after being pushed radially outward.This has the further advantage that the retaining ring 13 can be easily demolded and, together with the threaded part 15, can be pressed onto the container neck 30 with minimal force. The demolding from an injection mold and the pressing onto the container neck 30 can be achieved due to the flexibility of the wall section 73 without any risk of damage to the wall section 73. The initial opening of the lid 15 causes an asymmetrical load on the retaining ring 13. This results in the retaining ring 13 being pulled upwards with considerable force at the point where the lid 15 is pressed on, until the tamper bars 37 break. The novel mounting of the retaining ring 13 represents an advantageous addition to the present container closure 11, as it reliably prevents the retaining ring 13 from detaching from the container neck 30.

[0041] It is preferred that the inclined wall sections 73 have a reduced wall thickness compared to the rest of the retaining ring 13. In the Figure 15 It has been shown that the area of ​​the lower edge 71 has the smallest wall thickness. This further improves the radial outward flexibility of the wall section 73 described above. The wall thickness of the wall section 73 increases linearly downwards from the lower edge 71.

[0042] In the Figures 14 and 15 The retaining ring 13 is shown without the cover 15. In the Figure 14 and 15 It is clearly visible that above the slots 67 on the retaining ring 13 a ring ridge 81 is formed, on which the upper edges 69 lie.

[0043] In the Figure 15A first and second inclination angle 83, 85 are shown. The first inclination angle 83 indicates the inclination of the first section 75 relative to the plane of the lower edge 71. The first inclination angle 83 has a magnitude between 60 and 80 degrees, and preferably between 65 and 75 degrees. The larger the first inclination angle 83, the better the stability of the wall sections 73 against vertical forces or axial tensile forces caused by opening the cover 15. However, the first inclination angle 83 must not be too large, otherwise the annular projection 66 cannot be sufficiently engaged.

[0044] The second angle of inclination 85 indicates the inclination of the slot 67 relative to the plane of the lower edge 81. The connecting line 87, which represents the inclination of the slot 67, is a line connecting the upper edge 69 and the lower edge 71 in a plane spanned by the axis of rotation 31 and the connecting line 87. The second angle of inclination 85 is enclosed by the connecting line 87 and the plane 79. The second angle of inclination 85 has a magnitude between 30 and 50 degrees, and preferably between 35 and 45 degrees. The larger the second angle of inclination 85, the easier it is to demold the retaining ring 13. Legend:

[0045] 11 Container closure 13 Retaining ring 15 Lid 17, 17a, 17b Hinge, first hinge band, second hinge band 19 First angle of inclination 21 First projection, groove 22 Gap 23 Second projection, lid edge 25 Sealing element, sealing ring, lid surface 27 Pouring opening 29 Container 30 Container neck 31 Axis of rotation 32 Indentation 33 Crossbar 35 Upper edge of the retaining ring 36 Lower edge of the retaining ring 37 Warranty lugs 39 Retaining tongue 41 Tongue tip 43 Center of the lid 45 Opening angle 47 Open edge of the pouring opening 49 Second angle of inclination 51 Shoulder 53 Outer ring 55 Drive elements 57 Recesses 59 Step side 61 Slanted side 63 Gap 65 Projections 66 Ring-shaped projection 67 Slots 69 Top edge 71 Bottom edge 73 Wall section 75 First sub-section 77 Second sub-sections 79 Plane 81 Ring bead 83 First angle of inclination 85 Second angle of inclination 87 Connecting line

Claims

1. A container closure (11) made of plastic having - a retaining ring (13) for fastening the closure (11) to a container (29) with an upper and lower edge (35, 36), - a lid (15) connected to the retaining ring (13), - a hinge (17), which connects the lid (15) to the retaining ring (13) and around which the lid (15) can be pivoted relative to the retaining ring (13) from a closed position into a first open position and vice versa, - a sealing element (25), which is formed on the inner side of the lid (15) and which can seal a pouring opening (27) of the container (29) in the closed position, - a first appendage (21), which is formed on the retaining ring (13), and - a second appendage (23), which is formed on the lid (15), wherein the first and the second appendage (21, 23) engage with one another in the first open position and the lid (15) is thus locked in the first open position, characterized in that the sealing element (25) has a height and has formed a retaining tongue (39), in that the height of the sealing element (25) in the region of the hinge (17) is higher than on the remaining circumference of the sealing element (25), and that the lid (15) can be pivoted into a second open position, in which the retaining tongue (39) can rest against the open edge (47) of the pouring opening (27) or the upper edge (35) of the retaining ring (13).

2. The container closure according to claim 1, characterized in that the retaining tongue (39) has a tongue tip (41), which corresponds to the highest point of the sealing element (25).

3. The container closure according to claim 2, characterized in that the height increase on both sides of the tongue tip (41) is continuous.

4. The container closure according to one of the preceding claims, characterized in that along the circumference of the sealing element (25), the retaining tongue (39) has a length, which is defined in that the retaining tongue (39) draws an opening angle (45) with the center (43) of the lid (15), which is between 90 and 40 degrees, preferably between 80 and 50 degrees and particularly preferably between 70 and 60 degrees.

5. The container closure according to one of the preceding claims, characterized in that in the first open position, the retaining ring (13) and the lid (15) draw a first angle of inclination (19) between 180 degrees and 220 degrees and preferably between 190 and 210 degrees and that in the second open position, the retaining ring (13) and the lid (15) draw a second angle of inclination (49) between 70 and 90 degrees and preferably between 75 and 95 degrees.

6. The container closure according to one of the preceding claims, characterized in that the sealing element is a lid surface (25) with a ledge (51), which is offset in the direction of the retaining ring (13).

7. The container closure according to one of claims 1 to 5, characterized in that the sealing element is a sealing ring (25), which is oriented in the direction of the retaining ring (13).

8. The container closure according to one of the preceding claims, characterized in that at least one follower element (55) is formed on the lid (15) in the direction of the retaining ring (13), which follower element is received in a corresponding depression (57) provided on the retaining ring (13), when the lid (15) is in the closed position.

9. The container closure according to claim 8, characterized in that the follower element (55) has a ramp shape and has a step side (59) and an inclined side (61).

10. The container closure according to one of the preceding claims, characterized in that the first appendage is realized by means of a groove (21) formed on the retaining ring (13), the second appendage is realized by means of a protruding lid edge (23) and the lid edge (23) locks in place in the groove (21) in the first open position.

11. The container closure according to one of claims 1 to 9, characterized in that the first appendage has a gap (22) with an indentation (32), the second appendage (23) has a crossbeam (33) and the crossbeam (33) engages with the indentation (32) in the first open position.

12. The container closure according to one of the preceding claims, characterized in that the hinge (17) is formed by a first and a second hinge band (17a, 17b) and the first appendage (21) is formed between the first and the second hinge band (17a, 17b).

13. The container closure according to one of the preceding claims, characterized in that at least one tearable security web (37) connects the upper edge (35) to the lid (15) prior to the first-time opening on the circumference of the upper edge (35) of the retaining ring (13).

14. The container closure according to one of the preceding claims, characterized in that the container closure (11) can be snapped onto a container neck (30) of the container (29).

15. The container closure according to one of the preceding claims, characterized in that the container closure (11) is made in one piece.

16. The container closure according to one of the preceding claims, characterized in that the container closure (11) is made of polypropylene.

17. The container closure according to one of the preceding claims, characterized in that the retaining ring (13) has slots (67) arranged so as to be distributed over the circumference with an upper edge (69) and a lower edge (71), wherein the upper edge (69) is formed by a section of the retaining ring (13) running in a circular arc-shaped manner, and the lower edge (71) is formed by a wall section (73) inclined inwards in the radial direction and that the lower edge (71) of each slot (67) forms protrusions (65), whereby engagement means for a positive engagement with a ring-shaped protrusion (66) on the outer side of the container neck (30) are formed.