EP3807161B1 - Container with a bistable lid - Google Patents

Description

Snap closures are characterized in that they can snap in a bistable manner between an open and a closed state. They generally consist of a disk-shaped end wall, which can be deformed in a bistable manner between a concave first and a convex second state, and an annular edge section whose outer circumference reduces as the end wall transitions from the first to the second state.

In the patent documents DE 10 2015 103 036 B4 , which in Figure 11c discloses a closure system according to the preamble of claim 1, and which in Figure 5b discloses a closure system according to the preamble of claim 6, B4- and WO 2017/076398 A1 describes how snap fasteners that could previously only be made from metal and which are sold, for example, by the Hoffmann Neopac company as merchandising products under the brands Klick-Klack ^® and Klipp-Klapp ^® , can also be made from plastic. The transfer of the bistable deformation of the end wall to the adjacent annular edge section is crucial for the functioning of the snap mechanism. Only if the folding movement between the convex and concave curvature of the end wall passes on its deformation stress forces to the edge section can it lead to an expansion of the edge section and a corresponding increase in the outer circumference of the closure cap, which then also allows the container covered by it to be opened. It is of central importance that the angle included at the transition between the end wall and the edge section remains the same for both bistable states, ie that the closure cap material at this transition is stiff enough to pass on the deformation of the end wall completely to the edge section.

Furthermore, the edge section itself must be sufficiently stretchable in order to ensure an expansion of its outer circumference in the first bistable state of the end wall, which is curved in the insertion direction. This succeeds accordingly DE 10 2015 103 036 B4 for example, in that folds are formed on the edge section, which fold out in the first state and thus allow the outer circumference to be enlarged. Then the entire cover can be made from one be made from a single plastic material with homogeneous density or stretchability. Preferably, the edge section is given the necessary stretchability by at least one stretching section in the edge section of the cover being made from a softer material component than the remaining edge section (see WO 2017/076398 A1 ). The expansion section expands elastically under tension and allows the edge area to expand in the state of concave end wall curvature, while the base material of the cover is otherwise stiff enough to keep the angle in the transition area between the end wall and the edge section constant. This allows the cover to be folded into the bistable state with the larger outer circumference.

Preferably, the expansion section is manufactured together with the rest of the cover in one piece in a multi-component injection molding process. A second material component is then injected for the expansion section, which is softer and/or more elastic than the first material component used for the rest of the cover. In order to further support the constant angle in the transition area between the end wall and the edge section, the cover in this transition area can preferably have a higher material thickness of the harder (base) material component than in the main area of the end wall or can be injection molded from an even harder third material component. This leads to the particular advantage that the cover has a constant material thickness overall. A homogeneous thickness is not only visually appealing, but also reduces the number of steps and edges in which dirt can collect.

Particularly preferred is an embodiment in which a locking ring made of the softer second material component is molded onto the entire inner and/or outer circumference of the edge section. This can sealingly engage in a groove or a step in the side wall of the opening to be closed, so that a sealing closure of the opening is even possible.

With the previously known snap fasteners made of plastic, there is still a need for improvement with regard to the operation of the folding process by the user. So far it is mandatory to keep the cover on your Press in or pull up the edge section or on a handle element formed on its end wall with a certain minimum force in order to allow the end wall to snap from one bistable state to the other. This has the disadvantage that the areas on which the user is supposed to exert his force must always be sufficiently exposed in order to be able to reach the desired pressure points with the fingers, which in turn limits the design options for the closure system formed from the container and cover overall are undesirably restricted. On the other hand, it would be desirable to reduce the minimum amount of force required for the snapping process, provided the user applies the force at precisely predefined pressure points. It would also be advantageous if none of the snap states were triggered solely by a pulling force, because then a handle element (which can be operated with both hands) would not necessarily have to be provided on the cover.

Accordingly, the object of the present invention is to create a closure system consisting of a three-dimensional structure with the opening to be closed and with a cover that snaps between two states in a bistable manner, in which the options for triggering the snapping process are expanded for the user, and preferably the minimum effort required for triggering is reduced. What is particularly desirable is a locking system in which both bistable states can be triggered by manual pressure, so that both snapping processes can be triggered without a handle element and usually with one hand.

Two at least partial solutions to the above-mentioned problem are achieved through the features of the appended claims 1 and 6. The subclaims relate to preferred embodiments.

The two-part form of the independent claims is based on DE 10 2015 103 036 B4 as the closest state of the art. Other technical packaging solutions are in FR 670 576 A and DE 200 22 999 U1 disclosed.

According to the invention, the three-dimensional structure, in particular a container or a pipe end that is open at least on one side, is configured in such a way that a force acting on the closure system from the outside at at least one predefined point acts on the edge section of the cover in such a way is directed so that the cover snaps from one to the other bistable state.

In the case of a lid clamping against an opening wall on the inside, the opening wall of the three-dimensional structure is so flexible, at least at the predefined location, that it passes on a force acting on the opening wall transversely to the insertion direction at least on one side and preferably on both sides to the edge section of the lid by elastic deformation. As a result, the lid can lie completely within the opening to be closed without the user having to provide a handle element on the end wall of the lid to trigger the snapping process into the open position. Particularly preferably, the point of the opening wall that is furthest away from the insertion direction protrudes a certain distance from the point at which the edge section of the cover presses against the wall section from the inside on the circumference. A force acting transversely to the insertion direction on this outermost wall section can then trigger the lid to snap over with less effort because the protrusion acts as a lever arm.

According to another inventive solution, the cover acts as a cap from the outside around the wall section of the opening to be closed. Here, the geometric design according to the invention of the outermost end section of the opening wall in the opposite direction to the attachment direction makes it possible for the cap to contact this end section with an area of the end wall which is offset a little from the edge section in the direction of the center of the cap. As a result, the cap can be brought into its closed position not only by a force acting on the edge section transversely to the insertion direction, but also by a force exerted in the insertion direction, provided that this force is exerted on a pressure point that is located radially further out than the contact point of the cap Opening wall with the front wall. The distance between the contact point and the pressure point acts as a lever arm and reduces the amount of force required accordingly.

In the present description, the closure element of the opening to be closed is generally referred to as a cover. If the clamp fastening of the cover engages the outside of the opening wall, the cover is referred to as a cap; However, if the cover clamps against the inside of the opening wall, it is referred to as a lid.

• Fig. 1a eine teilweise im Schnitt dargestellte Seitenansicht einer Verschlusskappe gemäß einer ersten erfinderischen Lösung;
• Fig. 1b eine Draufsicht auf die Kappe der Fig. 1a;
• Fig. 1c eine vergrößerte Detailansicht in einem Schnitt A-A in der Fig. 1a;
• Fig. 1d eine vergrößerte Darstellung eines Ausschnitts X der Fig. 1a;
• Fig. 1e eine vergrößerte Detailansicht in einem Schnitt C-C in der Fig. 1c;
• Fig. 1f eine vergrößerte Detailansicht in einem Schnitt B-B in der Fig. 1c, in der gleichzeitig das Verschlussprinzips eines Behälters mit der Kappe dargestellt ist;
• Fig. 2a eine Querschnittsansicht eines Verschluss-Systems mit der Verschlusskappe gemäß der ersten erfinderischen Lösung in offener Stellung;
• Fig. 2b eine Querschnittsansicht des Verschluss-Systems der Fig. 2a in geschlossener Stellung;
• Fig. 2c einen vergrößerten Ausschnitt der Fig. 2a in einer ersten Variante der ersten Lösung in offener Stellung;
• Fig. 2d den vergrößerten Ausschnitt der Fig. 2a in einer zweiten Variante der ersten Lösung in offener Stellung;
• Fig. 2e den vergrößerten Ausschnitt der Fig. 2a in einer dritten Variante der ersten Lösung in offener Stellung;
• Fig. 3a eine Querschnittsansicht eines Verschluss-Systems der vorliegenden Erfindung mit einem Verschlussdeckel gemäß der zweiten erfinderischen Lösung in offener Stellung;
• Fig. 3b eine Querschnittsansicht des Verschluss-Systems der Fig. 3a in geschlossener Stellung;
• Fig. 3c einen vergrößerten Ausschnitt der Fig. 3b;
• Fig. 3d den vergrößerten Ausschnitt der Fig. 3c in einer ersten Variante der zweiten Lösung in geschlossener Stellung
• Fig. 3e den vergrößerten Ausschnitt der Fig. 3c in einer nicht erfindungsgemäßen zweiten Variante der zweiten Lösung in geschlossener Stellung; und
• Fig. 3f den vergrößerten Ausschnitt der Fig. 3c in einer dritten Variante der zweiten Lösung in geschlossener Stellung.

The invention is explained in more detail below using several exemplary embodiments. It shows:

• Fig. 1a a partially sectioned side view of a closure cap according to a first inventive solution;
• Fig. 1b a top view of the cap of the Fig. 1a ;
• Fig. 1c an enlarged detailed view in a section AA in the Fig. 1a ;
• Fig. 1d an enlarged view of a section X of the Fig. 1a ;
• Fig. 1e an enlarged detailed view in a section CC in the Fig. 1c ;
• Fig. 1f an enlarged detailed view in a section BB in the Fig. 1c , which also shows the closure principle of a container with the cap;
• Fig. 2a a cross-sectional view of a closure system with the closure cap according to the first inventive solution in the open position;
• Fig. 2b a cross-sectional view of the closure system Fig. 2a in closed position;
• Fig. 2c an enlarged section of the Fig. 2a in a first variant of the first solution in the open position;
• Fig. 2d the enlarged section of the Fig. 2a in a second variant of the first solution in the open position;
• Fig. 2e the enlarged section of the Fig. 2a in a third variant of the first solution in the open position;
• Fig. 3a a cross-sectional view of a closure system of the present invention with a closure lid according to the second inventive solution in the open position;
• Fig. 3b a cross-sectional view of the closure system Fig. 3a in closed position;
• Fig. 3c an enlarged section of the Fig. 3b ;
• Fig. 3d the enlarged section of the Fig. 3c in a first variant of the second solution in the closed position
• Fig. 3e the enlarged section of the Fig. 3c in a second variant not according to the invention, the second solution is in the closed position; and
• Fig. 3f the enlarged section of the Fig. 3c in a third variant of the second solution in the closed position.

At the in the Figures 1a-f In the first solution shown, the cover according to the invention is designed as a cap 20, which is intended to encompass a container wall 12a from the outside. The Figures 1a to 1f all show the cap 20 in its convex snap position, curved outwards (ie against the direction of insertion), which it assumes in its closed position. In the Figure 1f is also shown how in this position it is possible to snap into the opening wall 12a to be closed, but this will be explained later based on Figures 2a to 2e will be explained in more detail.

The ones in the Figures 1a-f Cap 20 shown has an end wall 21 of essentially circular basic shape, on the peripheral edge of which an annular edge section 22 is formed. The Figure 1a shows a partially sectioned side view. In the left half of the figure the cap 20 can be seen from the side, while in the right half it is cut open on the inside so that the rear inside of the cap 20 can be seen. In the figures, the uncut soft component (second material component) is always shown dotted and the cut soft component is shown cross-hatched, while the cut hard component (first material component) is shown simply hatched.

If the end wall 21 snaps into its concave downward state (ie in the insertion direction), the outer circumference of the edge section 22 increases. By the angle μ that the end wall 21 and the edge section 22 enclose in their transition area, in the two bistable ones To keep positions constant, the cap material should have sufficient rigidity. This is achieved according to the invention in that the transition between the end wall 21 and the edge section 22 has a higher material thickness than the central region of the end wall 21, at least in some sections, but preferably over the entire circumference. The material thickens, as in the Figures 1e and 1f shown, upwards, ie against the direction of attachment, so that the transition area between the end wall 21 and the edge section 22 runs smoothly on the inside. Alternatively, the material thickenings can also protrude downwards and lead to a correspondingly contoured wall inside the lid.

The enlargement of the outer circumference later based on the Figure 2a explained concave bistable state compared to that in the Figures 1e, 1f and 2 B The convex state shown requires sufficient expansion flexibility of the circumferential edge section 22. This is achieved according to the invention by circumferentially (preferably equidistantly) arranged expansion sections 24 made of the softer second material component, which - like particularly well in the Figures 1a and 1d can be seen - alternating with intermediate sections 23 made of the harder first material component. Like in the Fig. 1b shown, the expansion sections 24 start at the transition area between the end wall 21 and the edge section 22 and widen towards the radial outer edge. The softer material of the expansion sections 24 ensures that the edge section 22 can enlarge its outer circumference in the concave, ie open, snap position of the cap 20. The expansion sections 24 would then no longer be in the Figures 1a and 1d have the constant width shown, but widen radially outwards.

The edge section 22 ends both in its expansion sections 24 and in its intermediate sections 23 in an internally circumferential locking ring 29, which is also formed from a softer material component, preferably the same as the expansion sections 24. This internally circumferential locking ring 29 gives the thin-walled cap 20 additional dimensional stability, but is also sufficiently elastic to allow the enlargement of the outer circumference in the Fig. 2a to enable the convex folding position shown. Because of its softer material properties, the locking ring 29 can take on the function of a sealing ring.

The locking ring 29 is formed on a lip section 23a, 24a of the edge section 22 which projects radially inwards by 90°. This is because the cap 20 should encompass the opening 11a to be closed from the outside, as in the figure Figures 1f and in particular 2a-e will be explained in more detail. The lip section 24a adjacent to the expansion section 24 is made of the softer second material component, while the lip section 23a adjacent to the intermediate section 23 is made of the harder first material component. However, the lip sections 23a and 24a can also be formed completely from the softer second material component. Then the entire radially inwardly extending part of the edge section 22 would belong to the locking ring 29 or the lip section would be omitted.

The already mentioned multi-component injection molding from one or more thermoplastics is particularly suitable as a manufacturing process for the cap 20. Using the multi-component technique, a first (basic) component can be injected for the end wall 21 and the intermediate sections 23, while the expansion sections 24 as well as the locking ring 29 are directly injection-molded from a softer second component in a single manufacturing process. The optional third (particularly hard) material component for the transition area between the front wall and the edge section can also be injected directly in a single multi-component injection molding.

Preferred materials for the first component are: thermoplastic elastomers (TPE) and thermoplastic urethane (TPU).

Preferred materials for the second component are: polycarbonate (PC), acrylonitrile butadiene styrene (ABS) and polystyrene (PS).

Preferred materials for the third component are: glass fiber reinforced polyamide (PA) or other glass fiber reinforced plastics.

Instead of producing the cover completely by injection molding, a previously separately manufactured blank can also be overmolded. It is conceivable, for example, that a cap made of sheet metal or a light metal (e.g. aluminum), which essentially has the shape of a conventional click-clack can cap with the spreading metal pinnacles, is overmolded in the edge area with the softer (second) plastic component. This results in a cover with significantly improved tightness against the escape of liquids or gases from the can to be closed with it.

Instead of producing the cap or lid from several material components of different hardness or stretchability, it can also be made from just one plastic material by thermal forming, i.e. deep drawing, or an injection molding process. Then, instead of the softer expansion sections, the folds mentioned are formed on the edge section and reinforcement ribs and/or material thickenings are provided at the transition area between the end wall and the edge section, which keep the internal angle there constant in both bistable states.

The Figures 2a-e show the functional principle of the cap 20 according to the first inventive solution in a closure system according to the invention consisting of the container 10a and the cap 20. The opening 11a to be closed has an annular groove 13a on the outside in the wall section 12a shown, at the lower end of which there is a shoulder 15a is formed, but is not necessary and can also be omitted. Above the groove 13a, the wall section 12a continues in a projection 14a, which has essentially the same height as the edge section 22 of the cap 20.

Fig. 2a shows the cap 20 in its open, concave position, ie with the end wall 21 curved downwards. It has a correspondingly enlarged inner diameter of the edge section 22. This inner diameter is larger than the outer diameter of the outer groove 13a, so that the cap 20 is in the open state the Figure 2a can be removed from the opening 11a.

In the Figure 2b the end wall 21 has a convex curvature, ie it is curved upwards in the opposite direction to the insertion direction. The edge section 22 with the The inwardly projecting locking ring 29 then only has an inner diameter that is smaller than the outer diameter of the groove 13a. As a result, the cap 20 is firmly in engagement with the opening wall 12a to be closed and only snaps back into its first bistable state, which is in the Figure 2a is shown. Because of the elastic material properties of the locking ring 29, it also functions as a sealing ring to prevent gases or liquids from escaping from the opening 11a.

How particularly good in the Figure 2c can be seen, the end section 16 of the wall region 12a is beveled, that is to say the outer circumference of the opening 11a narrows in this end section 16, while the inner diameter of the opening 11a remains constant. This creates a contact point A1 between the end wall 21 and the end section 16, which is offset by a distance a1 from the transition area between the end wall 21 and the edge section 22 towards the center of the cover 20. If a force F ₂ acting essentially in the insertion direction is now exerted from above on the end wall 21 at a pressure point A2, this force F ₂ acts on the edge section 22 via the lever arm of length a1 and allows the snapping process to be triggered. So far this has only been essentially transverse to the attachment direction using the in the Figures 2a, 2c and 2d force F ₀ acting directly on the edge section 22 from the side is possible.

As also in the Figure 2c shown, an extension 18 can additionally be attached or formed on the edge section 22 according to an optional variant. This extension 18 allows the force F ₀ , which acts essentially transversely to the insertion direction and is necessary to close the cap, to be reduced to a lower value F ₁ because the user can exert his force via an extended lever arm when he holds the cap 20 on the Extension 18 compresses.

According to another variant, which is in the Figure 2d is shown, the lever arm a1 can be extended further in that the end section 16 'also has a narrowing 17 which is attached or formed on the end section 16' can be and in the area of the end section also narrows the inner diameter of the wall section 12a, i.e. the opening 11a. Then a force F ₃ exerted on the pressure point A2 acts even more efficiently on the edge section 22 via the longer lever arm a2 with the contact point A1 as the lever point and thus makes it easier to trigger the snapping process.

According to another variant, which is in the Figure 2e is shown, the lever arm a1 can be used Figure 2c can also be extended with an end wall extension 19. Unlike those in the Figure 2c shown extension 18, the end wall extension 19 is not arranged on the edge section 22 but on the end wall 21. This end wall extension 19 can be attached or formed on the end wall 21 in sections or over the entire circumference and allows the force F ₂ , which essentially acts in the insertion direction and is necessary to close the cap 20, to be reduced to a lower value F ₃ . to reduce. When the user pushes the cap 20 down at the pressure point A2 of the extension 19, an applied force F ₃ is created. via the longer lever arm a2' with the contact point A1 as the lever point, a greater torque than with the force _F2 and the lever arm a1 Figure 2c . Otherwise the structure corresponds to the variant Figure 2e the the Figure 2c . It also goes without saying that the Figures 2c, 2d and/or 2e shown variants can also be used in combination.

The Figures 3a to 3d and 3f show the functionality of a closure system according to the invention, in which a cover 30 of the second solution is used to close an opening 11a. The lid can be manufactured in the same way as described above for the cap 20 and has expansion sections and intermediate sections in the edge section 32 in the same way, although only the intermediate sections 33 can be seen in the cross sections of the figures for the sake of clarity. The lip sections and their variants are also possible in the lid 30 in a similar way to the cap 20.

The only difference to the cap 20 is that the cover 30 does not have an inwardly projecting locking ring 29, but rather an outwardly projecting locking ring 39, because it does not come from the outside, but from should clamp on the inside of the container wall. Of course, it is also conceivable to have a cover with both an outwardly and an inwardly projecting locking ring, which can then be used both as a cap and as a lid. Furthermore, in a closure system not according to the invention, the lid 30 could also be placed upside down on the can 10b without significantly changing its functionality. The middle section of the edge section 32 would then not extend in but against the insertion direction and the cover 30 would switch from its closed to its open state by pressing on the end wall 31 in the insertion direction, which can be advantageous for certain applications.

The edge section 32 therefore ends both in its expansion sections (not shown) and in its intermediate sections 33 in an externally circumferential locking ring 39, which is also formed from a softer material component, preferably the same as the expansion sections. This circumferential locking ring 39 gives the thin-walled lid 30 additional dimensional stability, but is also sufficiently elastic to allow the enlargement of the outer circumference in the Fig. 3b to enable the convex folding position shown. Because of its softer material properties, the locking ring 39 not only clamps particularly well in the inner groove 13b of the opening wall 12b to be closed, but can even take on the function of a sealing ring.

The wall area 12b of the opening 11a to be closed has an annular groove 13b on the inside, into which the cover 30 is intended to snap, and which forms a step-shaped shoulder 15b on its lower edge. The area of the wall section 12b above the groove 13b (that is, opposite to the insertion direction) is referred to as the projection 14b.

If you insert the cover 30 into the opening 11b from above, the edge section 32 with the locking ring 39 abuts against the shoulder 15b. This means that the user knows that he has reached the axial end position of the cover 30 intended for locking. If he now presses the end wall 31 downwards by a force F acting vertically downwards, the end wall 31 snaps away from its position Figure 3a shown convex bistable state to its in Figure 3b shown concave bistable state. Due to the rigidity of the cover material in the transition area between the end wall 31 and the edge section 32, which (as explained above) is preferably supported by material thickenings, the angle μ remains constant during this snapping process, so that the edge section 32 folds outwards slightly laterally and the lid snaps into place Locking rings 39 are effected in the groove 13b. The locking ring 39 therefore presses when the end wall is in the concave position Figure 3b laterally from the inside into the annular groove 13b of the opening wall 12b and thus locks the lid 30 in its closed position. The material in the expansion sections 34 stretches into a widened state in plan view and the outer diameter of the edge section 32 increases during this folding process. In the Figure 3c the engagement of the locking ring 39 in the groove 13b is shown again in detail.

In order to expose the opening 11b again, the cover 30 must snap back into its original state. Then it can be pulled out of the opening 11b again due to the reduction in its outer diameter. For this purpose, a handle element was conventionally provided on the end wall 31, by means of which the lid 30 can be grasped and pulled upwards. As described in detail below, the second inventive solution also enables the lid to be opened with a force F ₄ , F ₅ acting laterally (transversely to the insertion direction) on the container wall 12b, so that the handle element can be omitted.

As in the enlarged view of the Figure 3c Clearly visible, the projection 14b has a length b1 up to the outermost end of the wall section 12b in the opposite direction to the attachment direction. If the user now exerts a force F ₄ acting transversely to the insertion direction from the outside onto the wall section 12b at the pressure point B2, this acts with the length b1 as a lever arm and the contact point B1 between the wall section 12b and the edge section 32 due to the elastic deformation of the projection 14b on the lid 30 so that it can snap into the open state without the need for direct actuation of the edge section 32 or for the end wall 31 to be pulled up via a handle element or the like.

Like in the Figure 3d shown, the projection 14b 'can also be made longer according to a first variant of the second solution. This not only extends the lever arm to the length b2 and thereby correspondingly reduces the effort F ₅ required to open the lid 30, but the lid 30 is then also completely protected within the opening 11b, which makes it more difficult for the closure system to be opened unintentionally.

The Figure 3e shows an embodiment not according to the invention. Here, the wall section 12b has an opening below the inner groove 13b, in which a slide 13c is mounted. The slider 13c is a rod-shaped actuating element that can be displaced transversely to the insertion direction in the opening for opening the lid 30. To do this, the user exerts a force F ₅ 'from the outside transverse to the insertion direction on the trigger 13d attached or formed on the outer end of the slider 13c. In the variant shown, the trigger 13d has the shape of a hemispherical actuation button.

The other end of the slide 13c meets the end of an edge section extension 34 which protrudes from the edge section 32 in the insertion direction in the interior of the container 10b. The extension 34 can be attached or formed on the edge section 32 in sections or over the entire circumference. In the variant shown, it essentially has a length b3 and is therefore longer than the edge section 32 as such. The extension 34 acts as a lever arm of length b3 up to the transition area between the edge section 32 and the end wall 31.

If the slide 13c on the trigger 13d is pushed inwards with the minimum force F ₅ ', the extension 34 moves so far into the interior of the container that it applies the torque necessary for switching to the open bistable state to the end wall 31 via the lever arm b3 transmits. The same force F ₅ 'would not lead to the opening of the lid 30 on the remaining wall section 12b - for example because the wall thickness or strength of the container wall is large enough to transmit force to the edge section extension 34 to make it sufficiently difficult. This further increases safety against unintentional opening of the can-lid system.

As in the third variant of the inventive solution Figure 3f shown, the slide 13c with the trigger 13d can also be omitted and instead the wall section 12b has a constriction 13e at which the wall thickness is weakened. The constriction 13e can be provided as a circumferential annular recess or only as grip recesses arranged in sections, preferably at two diametrically opposite locations. If you press radially inwards in the area of the constriction 13e with the minimum force F ₅ ", the extension 34 deforms so far into the interior of the container that it applies the torque necessary for switching to the open bistable state to the end wall 31 via the lever arm b3 Apart from the wall thickness weakened by the constriction 13e, the container wall 12b is strong enough to avoid unintentional opening with the force F ₅ ". This makes it possible to avoid impairment of the container tightness of the second variant with the wall opening and the slider 13c. On the other hand, such wall breakthroughs are desirable for certain applications, for example for pressure equalization between the interior of the container and the ambient pressure. Instead of the constriction 13e, the wall section 12b can also be made softer in another way at this point, for example by using a softer material component or subsequently softening the wall section 12b at this point.

In summary, the present invention relates to a closure system with a three-dimensional structure 10a, 10b, in particular a container or an opening area of a technical apparatus, and a cover 20, 30 for plugging onto the three-dimensional structure 10a, 10b in order to close its opening 11a, 11b. The cover 20, 30 has an end wall 21, 31, which is deformable in a bistable manner between a first state curved in the insertion direction and a second state curved against the insertion direction, and an annular edge section 22, 32. This has a larger outer circumference in the first bistable state than in the second bistable state and is therefore designed to effect a clamping fastening of the cover 20, 30 to a wall region 12a, 12b of the opening 11a, 11b by the edge section 22, 32 inside in the first state or outside in the second state against the wall region 12a, 12b presses. The three-dimensional structure 10a, 10b is configured to transmit a force exerted from the outside on the closure system at predefined points A2, B2 in such a way that it causes the cover 20, 30 to snap over from one to the other of the two bistable states. <b>Reference symbol list</b> 10a, 10b container 11a, 11b opening 12a, 12b Side wall 13a External groove 13b Internal groove 13c Wall opening with slider 13d trigger 13e constriction 14a, 14b, 14b' Got over 15a, 15b Paragraph 16, 16' End section 17 narrowing 18 Extension edge section cap 19 Extension of the front wall 20, 30 cover 20 cap 30 Lid 21, 31 Front wall 22, 32 Edge section 23, 33 Intermediate sections (hard) 24 Stretch sections (soft) 23a Lip section inside (hard) 24a Lip section inside (soft) 29 Locking ring inside (soft) 33a Lip section outside (hard) 34 Extension edge section lid 39 Locking ring outside (soft) a1, b1, a2, a2', b2, b3 Lever arms A1, B1 Contact point A2, B2 pressure point

Claims (15)

1. A closure system comprising

   a three-dimensional structure (10b) having an opening (11b) to be closed, and

   a cover (30) for attachment onto said three-dimensional structure (10b) to close said opening (11b), said cover (30) comprising:

   a top wall (31) which is deformable in a bistable manner between a first state which is cambered in the direction of attachment and a second state which is cambered opposite to the direction of attachment; and

   an annular edge portion (32) having a larger outer circumference in the first bistable state than in the second bistable state and therefore being adapted to effect a clamping attachment of the cover (30) to a wall region (12b) of the opening (11b) in which, in the closed state of the closure system, the edge portion (32) of the cover (30) presses in the first state at a contact point (B1) from inside against the wall region (12b),

   characterized in that the three-dimensional structure (10b) is produced from a material which is, at least at a predefined location (B2), so flexible that a force (F₄, F₅, F₅', F₅") acting transversely to the direction of attachment on the wall region (12b) of the opening (11b) from at least one and preferably from two opposite outer sides onto the at least one predefined location (B2) is transferred in such a manner that the cover (30) is caused to snap from the first bistable state to the second bistable state.
2. The closure system according to claim 1, wherein

   the wall region (12b) has at least one narrowing point at which the size of the opening (11b) reduces, preferably in the form of a step-shaped shoulder (15b), and

   the size of the cover (30) is dimensioned such that, in the open state of the closure system, the cover fits into the opening (11b) only up to the narrowing point thereof and rests with its edge portion (32) against the narrowing point.
3. The closure system according to claim 2 wherein, in order to open the closure system,

   the force (F₄, F₅) acting transversely to the direction of attachment from two opposite outer sides acts on the wall region (12b) of the opening (11b) at the predefined location (B2) which is spaced from the narrowing point in the direction opposite to the direction of attachment, and

   the force (F₄, F₅) acts via a lever arm (b1, b2) formed by the distance between the predefined location (B2) and the contact point (B1) on the edge portion (32) abutting at the narrowing point and causes the cover (30) to snap from the first bistable state into the second bistable state.
4. The closure system according to claim 2 or 3, wherein the wall region (12b) has a groove (13b), which is spaced from the narrowing point in the direction opposite to the direction of attachment and which is configured to engage with a clamping element of the edge portion (32) of the cover, in particular a latching ring (39).
5. The closure system according to claim 1, wherein

   an extension (34) in the direction of attachment is attached to or integrally formed with the edge portion (32) and extends, in the closed state of the cover (30) in the direction of attachment, at least up to the predefined location (B2) of the three-dimensional structure (10b), and transfers a force (F₄, F₅, F₅', F₅") acting from two opposite outer sides of the wall region (12b) to the top wall (31) in such a manner that the top wall snaps from the first bistable state to the second bistable state; and

   the wall region (12b) preferably has a penetration at the predefined location (B2) with a sliding element (13c) which extends transversely to the direction of attachment and can be moved transversely to the direction of attachment on account of the force (F₅') acting from the at least one or preferably two opposite outer sides of the wall region (12b) so that it is being pressed against the extension (34) in order to open the cover (30).
6. A closure system comprising

   a three-dimensional structure (10a) having an opening (11a) to be closed, and

   a cover (20) for attachment onto said three-dimensional structure (10a) to close said opening (11a), said cover comprising (20):

   a top wall (21) which is deformable in a bistable manner between a first state which is cambered in the direction of attachment and a second state which is cambered opposite to the direction of attachment; and

   an annular edge portion (22) having a larger outer circumference in the first bistable state than in the second bistable state and therefore being adapted to effect a clamping attachment of the cover (20) to a wall region (12a) of the opening (11a) in which, in the closed state of the closure system, the edge portion (22) of the cover (20) presses in the second state from outside against the wall region (12a),

   characterized in that the wall region (12a) at its outermost end portion (16), when seen opposite to the direction of attachment, is shaped such that the outermost end portion (16) of the opening wall (12a) is shaped such that, in the open state of the closure system, the top wall (21) of the cover (20) contacts the opening wall (12a) at a contact point (A1) which is closer to the center of the opening than the transition region between the top wall (21) and the edge portion (22), and a force acting at at least one predefined location (A2), which is radially more outside than the contact point (A1) and serves as a pressure point (A2), acts on the edge portion (22) via a lever arm (a1, a2, a2') formed between the pressure point (A2) and the contact point (A1) and causes the cover (20) to snap over from the first bistable state to the second bistable state so that a snap-over of the cover (20) from the first bistable state to the second bistable state and thus a closing of the closure system cannot only be effected by a force (F₀, F₁) acting transversely to the direction of attachment from two opposite sides on the edge portion (22) of the cover (20) but also by a force (F₂, F₃, F₃') acting in the direction of attachment on the at least one predefined location (A2) of the top wall (21).
7. The closure system according to claim 6, wherein the outermost end portion (16, 16') of the opening wall (12a) has a shape which tapers transversely to the direction of attachment inwards.
8. The closure system according to claim 6 or 7, wherein the opening (11a) narrows at the outermost end portion (16, 16') of the opening wall (12a).
9. The closure system according to any of claims 6 to 8, wherein

   an extension (18) extending substantially in the direction of attachment is mounted or integrally formed at the edge portion (22) and extends the lever arm of the force (F₁), said force acting transversely to the direction of attachment from at least one and preferably from two opposite outer sides on the edge portion (22) for closing the closure system, and/or

   an extension (19) extending substantially transversely to the direction of attachment is attached or integrally formed at the top wall (21) and extends the lever arm (a2') of the force (F3'), said force acting in the direction of attachment on the predefined location (A2) for closing the closure system.
10. The closure system according to any preceding claim, wherein the three-dimensional structure (10a; 10b) is a container, in particular a box with a round opening (11a; 11b).
11. The closure system according to any preceding claim, wherein the cover (20; 30) is integrally made of plastics by a multi-component injection molding process.
12. The closure system according to any preceding claim, wherein the angle (µ) at which the top wall (21; 31) merges into the edge portion (22; 32) is constant, i.e. is the same in the first bistable state as in the second bistable state, and the angle (µ) is preferably greater than 90°, in particular between 100° and 120°.
13. The closure system according to any preceding claim, wherein the material thickness at the transition from the top wall (21; 31) to the edge portion (22; 32) is at least in partial regions larger than in the remaining region of the cover (20; 30), preferably plural times larger than the minimum material thickness of the top wall (21; 31), in particular approximately three to four times larger.
14. The closure system according to any of claims 1 to 5 and preferably according to any of claims 10 to 13 when not depending on any of claims 6 to 9, wherein the edge portion (32) in and outside a region with an expansion portion (24) has a central portion extending axially in the direction of attachment, and a lip portion (33a) adjacent to the central portion and extending radially outwards.
15. The closure system according to any of claims 6 to 9 and preferably according to any of claims 10 to 13 when not depending on any of claims 1 to 5, wherein the edge portion (22) in and outside the region with the expansion portion has a central portion extending axially in the direction of attachment, and a lip portion (23a, 24a) adjacent to the central portion and extending radially inwards.

Images