DE102015103036B4 - Bistable closure element - Google Patents

Abstract

Cover (10 ... 50) for attachment to an opening to be closed (1), with an end wall (11 ... 51), which in a bistable manner between a first curved in the mounting direction and a second state buckled against the mounting direction deformable is formed, and on the peripheral edge of the end wall (11 ... 51) integrally formed annular edge portion (12 ... 52), which is adapted to a clamping attachment of the cover (10 ... 50) on a wall portion (2) Opening (1) by the edge portion (12 ... 52) presses in the first state inside or in the second state on the outside against the wall portion (2), wherein the edge portion (12 ... 52) expansion grooves (14. ..54), which allow an enlargement of the outer circumference of the cover (10 ... 50) in the first bistable state in relation to the second bistable state, characterized in that the expansion grooves (14 ... 54) are formed by folding the edge section (10). 12 ... 52) are created starting from the Transition region between the edge portion (12 ... 52) and end wall (11 ... 51) extend to the outermost outer edge of the cover (10 ... 50) and which are adapted to spread from a folded to a spread state, when the end wall (11 ... 51) deforms from the second to the first bistable state, wherein the expansion grooves (14 ... 54) in radial openings (14a ... 54a) on the outer periphery of the edge portion (12 ... 52 ) end up.

Description

Since the 1920s, it has been known to produce small round metal cans with a snap closure, which can be opened and closed by pressure on its end wall in a bistable manner. Such snap closures are for example in the patent DE 442 634 described and consist of a circular end wall which is deformable in a bistable manner between a convex and a concave state, and a rim portion of crenellated spreader fingers, which are adapted to engage in the closure position, a bead on the outer edge of the metal can.

Such metal cans made of tinplate, for example, by the company Hoffmann Neopac sold as merchandising products under the click-clack-clack ^® or ^®. A more detailed description of such cans can be found for example in the patent EP 2 291 315 B1 ,

Not yet recognized and at least not described in the prior art, the transfer of the bistable deformation of the end wall to the adjacent annular edge portion is crucial to the functioning of the snap mechanism of the above-mentioned can closures. Only when the Umklappbewegung between convex and concave curvature of the front wall passes their Verformspannungskräfte to the edge portion, it can lead to a spreading of the metal crenels and a corresponding increase in the outer circumference of the cap, which then also allows opening of the metal can. Of central importance here is that the angle enclosed at the transition between the front wall and the edge section is the same for both bistable states, ie. H. the closure cap material is stiff enough at this transition to fully propagate the deformation of the end wall to the rim portion.

In the aforementioned metal can caps the required material stiffness in the transition between the end wall and edge portion is achieved solely by the fact that the pill box is formed from a piece of sheet metal by bending the edge region and punching the metal crenellated. Due to the bending hardening of the material at the transition between the end wall and the edge section, the required material rigidity is achieved automatically.

A disadvantage of the known click-clack caps, however, that they are currently available only from metal, especially tinplate. There is a general need for their production from cheaper and lighter plastic materials. Furthermore, it is desirable to be able to produce such doses so that they have in their closed state an end wall with concave curvature, because an unintentional opening is then difficult. Finally, it would be desirable to make such closure elements as air-tight and waterproof as possible in order to expand their applicability beyond the previous area as pill boxes out.

US Pat. No. 3,080,993 discloses a cover according to the preamble of present claim 1. Other conventional covers are shown in FIG DE 37 03 875 A1 . US Pat. No. 3,048,297 A . US 2 671 574 A . DE 10 2010 016 711 A1 . GB 697 583 A . US 3 559 843 A and GB 280 261 A described.

The object of the present invention is to make the click-click mechanism also available for thin-walled plastic covers. In particular, the covers should allow a reliable closing and opening and be produced as inexpensively as possible.

An at least partial solution of this object is achieved by the features of appended claim 1. The subclaims relate to preferred embodiments.

In order for the production of plastic caps to succeed, it is crucial to gain the knowledge and implement that the angle at the transition between the end wall and the edge portion in both bistable positions must remain constant. In the conventional metal metal can closure, this boundary condition was more or less coincidentally fulfilled by the fact that the tinplate material in this transition region was sufficiently rigid due to the bending hardening. In a production of plastic but no such bending hardening, so that the necessary material stiffness must be achieved in other ways.

This is achieved according to the invention in that stiffening ribs are provided in the transition region between the end wall and the edge section, which, according to the principle of a bead, make it difficult to change the angle in the transitional area. Alternatively, the stiffening can also be achieved by increasing the material thickness at the points in question.

For reasons of stability, a closed edge area design should be chosen instead of the metal curbs in the conventional metal closure cap for thin-walled plastic closures. Optically and functionally, this also represents a desirable improvement. According to the invention, expansion grooves are provided in the edge section, which allow widening of the edge region in the state of concave front wall curvature. These Expansion grooves can be made as material bulges from the plane defined by the annular edge portion or exist in thinned with respect to the average wall thickness radial regions of the edge portion.

The material thickening or dilutions can be produced well in plastic in the functionally necessary extent by injection molding. The variant with the stiffening ribs and expansion grooves as actual bead-like bulges of plastic material with substantially the same wall thickness can also be realized in the particularly inexpensive convertible thermal forming process (so-called deep drawing).

According to a particularly preferred embodiment, the end wall further comprises a handle element on which the end wall can be easily lifted by hand and pressed. This is particularly important if the closure element is not from the outside as a cap sitting over the opening to be closed, but engages as a lid inside in the side wall of the opening to be closed. In the closed state, the lid could then no longer be removed from the opening without a matching handle element. The grip element also has the advantage that it reinforces the center region of the end wall, which should remain as stiff as possible in its horizontal alignment during the folding process between convex and concave position.

Particularly preferred is an embodiment of the present invention, wherein the side wall of the opening to be closed inside on a shoulder, a step or the like, a sealing element, in particular an O-ring, against which the lid according to the invention in the closed state with its edge portion so firmly is pressed that a sealing closure of the opening is possible. This idea of a seal was in the conventional caps made of metal already not possible because they always came out of the way into engagement with the metal can and also the slots between the star-shaped arranged on the edge portion metal crenels have not allowed a sealing design.

In the following, the invention will be explained in more detail with reference to several embodiments. It shows:

1a a partially sectioned side view of a cap according to a first embodiment of the invention;

1b an enlarged view of a section Y of 1a ;

1c an enlarged detail view in a section Z in the 1a ;

1d an enlarged view of a section X of the 1a ;

1e a plan view of the cap of 1a ;

2a a partially sectioned side view of a cap according to a variant of the first embodiment of the invention;

2 B an enlarged view of a section Y of 2a ;

2c an enlarged detail view in a section Z in the 2a ;

2d an enlarged view of a section X of the 2a ;

2e a plan view of the cap of 2a ;

3a a partially sectioned side view of a cap according to a second embodiment of the invention;

3b an enlarged view of a section Y of 3a ;

3c an enlarged detail view in a section Z in the 3a ;

3d an enlarged view of a section X of the 3a ;

3e a plan view of the cap of 3a ;

4a a partially sectioned side view of a cap according to a variant of the second embodiment of the invention;

4b an enlarged view of a section Y of 4a ;

4c an enlarged detail view in a section Z in the 4a ;

4d an enlarged view of a section X of the 4a ;

4e a plan view of the cap of 4a ;

5a a cross-sectional view of a closure system according to the present invention with the closure cap according to the second embodiment in the closed position;

5b the closure system according to 5a in open position;

6a a closure system according to the present invention with a closure cap according to a third embodiment in the open position;

6b the closure system according to 6a in closed position;

7a a partially sectioned side view of a cap according to a fourth embodiment;

7b an enlarged section of the Y 7a ;

7c an enlarged section X of the 7a ;

7d a plan view of the cap of the 7a ;

8a a partially sectioned side view of a cap according to a fifth embodiment;

8b an enlarged section of the Y 8a ;

8c an enlarged section X of the 8a ;

8d a plan view of the cap of the 8a ;

9a a partially sectioned side view of a cap according to an example 1 useful for understanding the present invention;

9b a plan view of the cap of the 9a ;

9c an enlarged section X of the 9a ;

9d a cross-sectional view along the line AA of 9a ;

9e a cross-sectional view along the line BB of 9d ;

9f a cross-sectional view along the line CC of 9d ;

10a a partially sectioned side view of a cap according to an example useful for understanding the present invention 2;

10b a plan view of the cap of the 10a ;

10c an enlarged section X of the 10a ;

10d a cross-sectional view along the line AA of 10a ;

10e a cross-sectional view along the line BB of 10b ;

10f a cross-sectional view along the line CC of 10b ;

11a a cross-sectional view of a closure system according to the present invention with a variant of the cover according to the second embodiment in the open position;

11b an enlarged section X of the 11a ;

11c a cross-sectional view of the closure system of 11a in closed position;

12a a cross-sectional view of a closure system according to the present invention with a closure cap according to a useful for understanding the present invention Example 3 in the closed position;

12b an enlarged section X of the 12a ;

12c a cross-sectional view of the closure system of 12a in open position;

13a a cross-sectional view of a closure system according to an example 4 useful for understanding the present invention in the open position; and

13b a cross-sectional view of the closure system according to 13a in closed position.

In the present description, the closure element of the opening to be closed is generally referred to as a cover. Attaches the clamp attachment of the cover outside of the Opening wall, the cover is referred to as a cap; on the other hand, if the cover jams against the opening wall inside, it is called a lid.

The 1a to 1e show details of the cap according to the invention 10 according to the first embodiment. The snap cap 10 can be in a particularly material-saving and cost-effective manner by a so-called thermal process (also called thermoforming, deep drawing or vacuum deep drawing) made of a piece of plastic. Suitable base materials are in particular thin films of thermoplastics, such as PET, PS and PP. Other manufacturing methods such as injection molding but are also suitable, the cap 10 manufacture.

The cap 10 has an end wall 11 of substantially circular basic shape, at its peripheral edge an annular edge portion 12 is formed. The edge portion has, as in the enlarged views of 1c and 1d good to see, a substantially axially, ie extending along the slip-on center section 17 and a transverse thereto, ie extending in the radial direction lip portion 18 on. At the middle section 17 are radially inwardly projecting locking nubs 19 formed, which are designed for a clamping engagement in an opening outer wall (in particular in an annular groove provided therein).

The cap 10 is in the 1a to 1e shown in its open position, ie the end wall 11 is located, as in the 1a seen in their concave downward (ie in slip-on) arched bistable state. Grab the front wall 11 in their convex, upwardly curved state, so reduces the inner and outer circumference of the edge portion 12 so that the locking knobs 19 engage with the wall portion of the opening to be closed (not shown).

To the angle μ in the 1d the front wall 11 and the edge section 12 in their transition region, to keep constant for both bistable states, the cap material should have sufficient rigidity. This is possible according to the invention in covers produced by the thermal process 10 having substantially homogeneous wall thickness in that in the transition region between the end wall 11 and edge section 12 stiffening ribs 13 are provided. These stiffening ribs 13 run, as in the 1a . 1d and 1e can be seen from the radially outer region of the end wall 11 radially outward and extend over the entire central portion 17 of the border area 12 , They thus represent according to the principle of the bead a transverse to the material plane elevation or depression, which is a stiffening of the cover 10 creates in the range of the angle μ.

The enlargement of the outer circumference in the concave bistable state shown in relation to the (not shown) convex state also requires a sufficient expansion flexibility of the peripheral edge region 12 , This is achieved according to the invention by circumferential (preferably equidistant) expansion grooves 14 , which - how particularly good in the 1a and 1b can be seen - at the top, to the front wall 11 adjacent edge of the middle section 17 attach and from there obliquely outward to the radially outer edge of the lip portion 18 run while the middle section 17 in the remaining area away from the expansion grooves 14 yes axially, that extends along the mounting direction down and from there substantially perpendicular to the lip portion 18 passes.

The so created foldings of the edge section 12 create expansion grooves 14 which are similar in structure to webs and a desired increase in the outer circumference or diameter of the cover 10 between the two bistable states. It is important to ensure that the folds reach to the outermost edge, that is, that the expansion grooves 14 on the outer circumference of the lip portion 18 radial openings 14a form. Only through these approximately semicircular openings 14a can the edge section 12 in the concave folded down state actually "unfold" and enlarge its outer circumference compared to the convex upwardly folded state.

The 2a to 2e show a variant of the first embodiment, in which in addition to those already with respect 1a to 1e parts described a handle element 15 is provided in the end wall. This handle element 15 is preferably in a centric in the end wall 11 uplifting Griffdom with on its side wall outwardly projecting handle knobs 16 ,

As in 2a can be seen, has the front wall 11 in its central region a substantially cylindrical bulge upwards (ie against the Aufsteckrichtung), at which the cap 10 good grip and thus as a grip element or Griffdom 15 acts. Due to the centric arrangement in the middle area of the front wall 11 allows the Griffdom 15 Safe handling of the cap 10 and avoids tilting of the cap 10 , the one-sided lateral peeling of the same at the edge portion 12 otherwise it could easily occur.

For the variant of the first embodiment according to the 2a to 2e is in turn, a production in particularly material-saving thermoforming possible. Of course, however, other manufacturing methods, such as injection molding are also conceivable here.

The 3a to 3e show the cap 20 according to the second embodiment. Function and effect of the bistable snap mechanism with the end wall 21 , the edge section 22 , the stiffening ribs 23 , the expansion grooves 24 , the middle section 27 , the lip section 28 and the locking knobs 29 are the same as in the first embodiment and are therefore not explained here.

The main difference to the first embodiment is that the angle β in the transition region between the end wall 21 and the edge section 22 greater than 90 °, while in the first embodiment, the corresponding angle μ was less than 90 °. This leads to a generally different cap geometry, because then the middle section 27 of the border area 22 in the in 3a shown convex curvature of the front wall 21 axially, ie parallel to the mounting direction and opening wall. In the concave bistable state (not shown), ie when the end wall 21 is pressed down, the wall of the central section arises 27 diagonally outwards.

The cover 20 can therefore also be used well as a lid, because the obliquely outwardly directed wall of the central portion 27 a corresponding radial deflection of the lip portion 28 The result is an intervention of the lip section 28 allows in a corresponding groove on the inner wall opening. This will be later based on the 11 be explained in more detail. In this case, the in 3a shown position of the cover 20 show the open state. Conversely, the cover can be 20 but also use as a cap when the locking knobs 29 in the in 3a shown position outside the opening wall engage and by jumping the end wall 21 in its concave position (not shown) release the opening wall again.

The 4a to 4e relate to a variant of the second embodiment. Similar to the one in the 2a to 2e shown variant of the first embodiment, in the variant shown again in addition a handle element 25 in the form of a handle dome with handle nubs 26 intended. The remaining elements of the cover 20 are opposite to in the 3a to 3e shown embodiment unchanged.

The 5a and 5b show the functional principle of the cap 20 in a closure system according to the invention. The 5a schematically shows the opening to be closed 1 between the wall sections shown in cross-section 2 , Outside of the circular opening wall is an annular groove 3 introduced, in which the locking knobs 29 the cap 20 in the in 5a can lock in the closed position shown. Instead of an annular groove 4 Of course, individual wall recesses may be provided, the number of the number of locking knobs 29 corresponds.

In 5a has the front wall 21 a convex curvature, ie it is curved against the direction of attachment upwards. The edge section 22 extends from an inner diameter a, at which the locking nubs 29 projecting inwardly, to an outer diameter b, which is the outermost radial extent of the lip portion 28 represents. If one exercises a force F ₁ acting in the direction of attachment on the end wall 21 out, so the cap snaps 20 in their second bistable state, which in the 5b is shown.

Like in the 5b to recognize, has the cap 20 in their open, concave state (ie with bulging end wall 21 ) a correspondingly enlarged inner diameter a 'and outer diameter b' of the edge portion 22 , The inner diameter a 'is thus greater than the outer diameter of the opening wall, so that the cap 20 in the open state of 5b from the opening 1 lose weight. By exerting a force F ₂ acting counter to the slip-on direction on the end wall 21 (preferably by lifting the handle dome 25 ), grab the cap 20 back to their first bistable state.

As later from the 11 will be seen, the enlargement of the outer diameter b 'can also be used to close the opening when the cover 20 is used in a correspondingly larger opening as a lid.

The 6a and 6b show a cover according to the invention 30 according to a third embodiment. Unlike the first two embodiments, the required stiffening of the material in the transition region between the end wall 31 and edge section 32 achieved here not by the formation of material bulges or beads, but by increasing the wall thickness in this transition region. The increase in wall thickness can also be provided only in individual sections of the total circumference, so that one can again speak of stiffening ribs, but then of those with concomitant increase in wall thickness.

Furthermore, in the third embodiment, the grip element is no longer in the form of a handle dome, but as a handle or bow handle 35 , This has the advantage that the bracket can engage behind with a hook or the like, so that the handle element 35 can be detected sufficiently reliably and reliably without the provision of appropriate handle knobs.

These design options are bought with the disadvantage that for the cap 30 a production in the preferred thermoforming process is no longer possible. This method does not allow such different wall thicknesses or material distributions in the form of the bow handle shown 35 , However, a production by injection molding of a thermoplastic or a light metal (eg aluminum) is quite possible.

The 6a shows the cap 30 in its open position on the opening to be closed 1 , As with the 5a and 5b has the side wall 2 the opening 1 outside an annular groove 3 on, in which the locking knobs 39 intervention. The cap 30 is then in the closed state of 6b ie the front wall 31 has a convex curvature upward, opposite to Aufsteckrichtung. A comparison of the inner diameter b and b ', ie the distance between the two diametrically opposed locking knobs shown 39 , for the 6a and 6b makes it clear that b 'is smaller than the outside diameter of the opening wall 2 in the area above the groove 3 while baht is bigger than this. Therefore, the cap 30 in the open position from the opening 1 removable and can in the closed position from the outside into the groove 3 the opening wall 2 intervene around the opening 1 to close.

The edge section 32 has no more lip section, because this manufacturing technology in an injection molding process (unlike the thermoforming process) is no longer required. Of course, if desired, a radially outwardly projecting lip portion may also be provided in the injection molding process for the third embodiment, for example when the cover is used 30 do not want to use as a cap but as a lid. Then you could but also the locking nubs 39 do not allow to protrude inward but outwards, so that they from the inside into corresponding grooves of the opening walls 2 can engage. 6a then would the closed position and 6b show the open position. This principle will be explained in more detail below on the basis of 12a to 12c explained.

The 7a to 7d show a fourth embodiment of the present invention. In this are the stiffening ribs 43 and the expansion grooves 44 not like in the 1 to 4 offset from each other in the circumferential direction, but go directly into each other, which brings a simplification in the production with it. In other words, the stiffening ribs run 43 to the radial outer end of the edge portion 42 and take over the function of the expansion grooves 44 equal to.

Also, the total number of ribs 43 and grooves 44 twice as high as the 1 to 4 , The functioning of the ribs 43 and grooves 44 but is essentially the same as the 2a to 2e , The same applies to the front wall 41 , the edge section 42 , the Griffdom 45 , the handle knobs 46 , the middle section 47 , the lip section 48 and the locking knobs 49 , The angle μ, the end wall 41 and the edge section 42 in their transition section is again less than 90 °. In contrast, the angle β in the 8a to 8d greater than 90 °, so that the fifth embodiment in this aspect with the embodiment of 4a to 4e corresponds.

The cap 50 of the fifth embodiment, therefore, has the end wall 51 , the edge section 52 , the stiffening ribs 53 , the expansion grooves 54 , the Griffdom 55 , the handle knobs 56 , the middle section 57 , the lip section 58 and the locking knobs 59 , which correspond in their operation exactly the corresponding elements of the fourth embodiment. Unlike this, the cap points 50 but stiffening ribs 53 on, which (as already with regard to the 7a to 7d mentioned) directly into the expansion grooves 54 pass over and are increased in number.

The 9a to 9f show a cap 60 according to Example 1 useful for understanding the present invention 9b can be seen, assigns the cap 60 a substantially disc-shaped end wall 61 and a peripheral portion surrounding this ring 62 on. The edge section 62 sits down, as in the 9f shown, from an axially extending central portion 67 and a radially extending lip portion 68 together, being at the central portion 67 radially inwardly projecting locking nubs 69 are formed.

How very good at the 9d can be seen, are the stiffening ribs 63 by radially inwardly projecting material thickening in the transition region between the end wall 61 and edge section 62 educated. These reinforce the transition area between the front wall 61 and edge section 62 and thereby help to keep the transition angle constant. Corresponding to this are the expansion grooves 64 formed by peripheral portions with thinner wall thickness (see 9e ). The stiffening ribs 63 and the expansion grooves 64 lead on Kappeninneren to a correspondingly contoured wall course, but are from the outside in the Top view of 9b not to be seen. The cover 60 This has a particularly advantageous homogeneous appearance.

In the central area of the front wall 61 is the handle element 65 molded, which - as with the 6 - Is designed as a bow handle. The special shape of the grip element 65 and the relatively large differences in wall thicknesses require a manufacturing process that can meet these specifications. This is not possible with a thermoforming process, but with an injection molding process or the like.

The 10a to 10f show an example useful for understanding the present invention 2. In this are the stiffening ribs 73 and the expansion grooves 74 no longer inwardly, but radially outwardly formed so that they in the top view of 10b are clearly visible. Only the locking knobs 79 the cap 70 are necessarily further formed as inwardly projecting bulges. The functioning of the front wall 71 , the edge section 72 with its middle section 77 and his lip section 78 and the handle element 75 is otherwise unchanged from Example 1 of 9a to 9f ,

The stiffening ribs 63 . 73 are like in the 9 and 10 shown, formed only in sections or peripheral segments. Just as well, the transition between the front wall 61 . 71 and edge section 62 . 72 but also have a higher material thickness over the entire circumference. For functional creation of the expansion grooves 64 . 74 In contrast, only a segmental thinning of the material is actually required.

The 11a to 11c show the operation of a closure system according to the invention, in which a variant of the cover 20 of the second embodiment as a lid for closing the opening 1 is used. The wall area 2 the opening to be closed 1 has an annular groove inside 4 and a radially inwardly projecting heel below 5a on.

If you lead the cover 20 from above into the opening 1 a, so comes the lip section 28 of the border area 22 against the paragraph 5a , As a result, the user knows that he provided for locking the axial end position of the lid 20 has reached. Now he pushes the front wall 21 down (best by a vertically downward force F ₁ on the handle element 25 ), so the front wall jumps 21 from her in 11a shown convex bistable state around in their in 11b shown concave bistable state. Due to the stiffness of the lid 20 in the transition area between the front wall 21 and edge section 22 passing through the stiffening ribs 23 is achieved or enhanced, the angle β remains constant in this Umspringvorgang, so that the edge portion 22 slightly laterally outward folds and a pressure of the lip section 28 in the groove 3 causes. The material stretches in the expansion grooves 24 from a folded to a spread state.

Like in the 11c can be seen, thereby increasing the inner diameter of the edge portion 22 from a to a 'and the outer diameter of the edge portion 22 from b to b '. Further press the lip sections 28 at concave end wall position laterally from the inside into the annular groove 4 the opening wall 2 and lock the lid 20 in its closed position.

Around the opening 1 To uncover again, you pull the front wall 21 with a force F ₂ upwards (best by gripping the handle dome 25 with the Rutschnoppen 26 ), eliminating the cover 20 snaps back to its original state and by reducing its outer diameter to the value b back out of the opening 1 can be pulled out.

Particularly advantageous on the closure system according to the 11a and 11b is that the lid 20 not by a pressure from outside on his front wall 21 can be opened. Unlike the conventional click-click cans and also in the closure system according to the present 5 and 6 becomes the lid 20 in the 11a with a vertical pressure on his front wall 21 not released from above (eg due to impacts during transport). Instead, the bulkhead needs 21 by deliberately pulling up the handle dome 25 be pulled out of its locked position. This will ensure the safety of the cover 20 increased against unintentional opening. Preferably, the cover 20 completely within a pipe end to be closed when in the 11a and 11b the groove 4 and the paragraph 5a are arranged accordingly below.

The 12a to 12c show a closure system with the same basic principle as in the 11a and 11b but a differently designed cap 80 , The lid 80 according to the example 3 useful for understanding the present invention no longer has the stiffening ribs formed as material bulges 23 and expansion grooves 24 of the second embodiment, but corresponding reinforcing and expansion elements, which - as previously with reference to the 9 and 10 was explained - are made by thickening material or dilutions. Unlike the 11a and 11b is also the angle μ in the transition region between the end wall 81 and edge section 82 not greater than 90 ° but less than 90 °.

The basic principle of increasing the outside diameter from a value b 'in the open state of 12c to a value b in the closed state of 12a but is unchanged from the 11a and 11b , Also the advantage of only by pulling out on the handle element 85 opening lids 80 remains. As a manufacturing process for the lid 80 In particular, an injection molding process is advantageous because it contains the different wall thicknesses of the cover 80 easy to train.

The 13a and 13b show a closure system according to Example 4 useful for understanding the present invention. This example is also particularly good with that in the 7 and 8th shown variant of a cover can be realized in which the reinforcing ribs pass directly into the expansion grooves.

In example 4, in addition to the advantages already mentioned, the intention is to have as tight a locking of the cover as possible 90 in their closed state. The opening wall 2 For this purpose, it can have a thicker wall diameter in its end region, so that a step is formed on the inner wall 5b forms, in which a sealing element 6 , preferably an O-ring, is inserted. Now press the lip section 98 the closure lid 90 in his in 13b shown closed state radially from the inside against the sealing ring 6 , so creates an air and liquid-tight connection between the edge portion 92 and the opening wall 2 ,

The jumping of the lid 90 from his in 13a shown convex curvature state with upwardly curved end wall 91 in his in 13b shown concave state with downwardly arched end wall 91 succeeds - as with the 12a to 12c - By a stiffening of the transition region between the end wall 91 and the edge section 92 because of the thicker wall thickness used there. Also, the advantage of not acting by axially down forces but only by pulling the lid 90 with the force F ₂ (preferably on the bow handle 95 ) again from its closure position releasing cover member is retained in Example 4.

In addition to the above-mentioned sealing mechanism, the lid has 90 an extension 90a the front wall 91 beyond the transition area on. The front wall 91 So not only goes into the edge section (with the constant angle β) 92 over, but branches out there T-shaped also to a Umfangsendabschnitt 90a , This essentially serves to the end wall 91 extend radially outward so far that a visible from the outside gap between the central portion 97 and the inner wall of the opening 1 is prevented, which acts visually disturbing and could fall into the debris or the like.

The peripheral end portion 90a takes in the example 4 of 13 in an annular outer groove 9 the opening wall 2 , Against the inward facing side wall of this groove 9 the end section is supported 90a in the locked position the 13b and thus presses against a second sealing element 8th at the axial edge end portion of the opening wall 2 is arranged. This second sealing element 8th (preferably again an O-ring) leads to an improvement of the sealing effect, but can also be omitted, since already the seal by means of the first sealing ring 6 and without the end section 90a is sufficient for most purposes. Through the annular outer groove 9 the opening wall 2 and the stage 5b becomes the peripheral edge 7 easily movable, which has an advantageous effect on the geometry of the closure mechanism and its sealing.

In summary, the present invention relates to a cover 10 ... 50 with a bistable folding mechanism, wherein the cover is preferably made of plastic and is particularly preferably produced in a thermoforming process. At the transition area between the front wall 11 ... 51 and the edge section 12 ... 52 are reinforcing elements, in particular stiffening ribs 13 ... 53 , provided that ensure that one in the transition area from the side wall 11 ... 51 and the edge section 12 ... 52 included angle β, μ remains constant in both bistable states. In the edge section 12 ... 52 provided expansion grooves 14 ... 54 preferably provide that the outer periphery of the edge portion 12 ... 52 can increase or decrease from one bistable state to another bistable state.

Claims (10)

Cover ( 10 ... 50 ) for attachment to an opening to be closed ( 1 ), with an end wall ( 11 ... 51 ) which is deformable in a bistable manner between a first state arched in the slip-on direction and a second state curved against the slip-on direction, and one at the peripheral edge of the end wall ( 11 ... 51 ) formed annular edge portion ( 12 ... 52 ), which is adapted to a clamping attachment of the cover ( 10 ... 50 ) on a wall area ( 2 ) of the opening ( 1 ) by causing the edge portion ( 12 ... 52 ) in the first state inside or in the second state outside against the wall area ( 2 ), the edge section ( 12 ... 52 ) Expansion grooves ( 14 ... 54 ), which is an enlargement of the outer circumference of the cover ( 10 ... 50 ) in the first bistable state relative to the second bistable state, characterized in that the expansion grooves ( 14 ... 54 ) by folding the edge section ( 12 ... 52 ), starting from the transition region between edge section ( 12 ... 52 ) and end wall ( 11 ... 51 ) to the extreme outer edge of the cover ( 10 ... 50 ) and which are designed to spread from a folded to a spread state when the end wall ( 11 ... 51 ) deformed from the second to the first bistable state, wherein the expansion grooves ( 14 ... 54 ) in radial openings ( 14a ... 54a ) on the outer periphery of the edge portion ( 12 ... 52 ) end up. Cover ( 10 ... 50 ) according to claim 1, wherein the angle (β, μ) under which the end wall ( 11 ... 51 ) in the marginal section ( 12 ... 52 ), is constant, ie, is the same in the first bistable state as in the second bistable state. Cover ( 10 ... 50 ) according to claim 1 or 2, wherein in the transition region between the end wall ( 11 ... 51 ) and edge section ( 12 ... 52 ) Stiffening ribs ( 13 ... 53 ) are provided, which extend in the radial direction, and / or the material thickness at the transition from the end wall ( 31 ) in the marginal section ( 32 ) is greater at least in partial areas of the outer end wall circumference than in the remaining area of the cover ( 30 ), preferably many times higher than the minimum material thickness of the end wall ( 31 ), in particular about three to four times as large. Cover ( 10 ... 50 ) according to any one of the preceding claims, wherein the edge portion ( 12 ... 52 ) an axially extending in Aufsteckrichtung middle section ( 17 ... 57 ), and the middle section ( 17 ... 57 ) in the radial direction outwardly or inwardly projecting locking nubs ( 19 ... 59 ), which the clamping action in the attachment of the cover ( 10 ... 50 ) on the wall area ( 2 ) of the opening ( 1 ). Cover ( 10 ... 50 ) according to claim 4, wherein the edge portion ( 12 ... 52 ) one to the middle section ( 17 ... 57 ) adjacent and extending in the radial direction lip portion ( 18 ... 58 ), and the expansion grooves ( 14 ... 54 ) starting from the transition region between edge section ( 12 ... 52 ) and end wall ( 11 ... 51 ) radially outwardly and obliquely downward and in the radial openings ( 14a ... 54a ) on the outer circumference of the lip portion ( 18 ... 58 ) end up. Cover ( 10 ... 50 ) according to one of the preceding claims, wherein the end wall ( 11 ... 51 ) a counter to the Aufsteckrichtung excellent grip element ( 15 ... 55 ), which for plugging and removing the cover ( 10 ... 50 ) on or from the opening ( 1 ) serves. Cover ( 10 ... 50 ) according to claim 6, wherein the handle element ( 15 ... 55 ) has a side wall extending in the slip-on direction, from which preferably one or more outwardly projecting bulges (FIG. 16 ; 26 ; 46 ; 56 ), which improve the slip resistance when gripping as knobs, or the handle element ( 35 ) is designed as a bow handle. Cover ( 10 ... 50 ) according to one of the preceding claims, wherein the cover ( 10 ... 50 ) made of plastic in one piece by a thermoforming method or an injection molding method. Closure system with an opening to be closed ( 1 ), at the wall area ( 2 ) the cover ( 10 ... 50 ) is to be clamped and with the cover ( 10 ... 50 ) according to claim 5 or any claim dependent on claim 5, wherein the wall area ( 2 ) an inner groove ( 4 ) for engaging the lip portion ( 18 ... 58 ), or the cover ( 10 ... 50 ) according to claim 4 or any claim dependent on claim 4, wherein the wall area ( 2 ) an outer groove ( 3 ) for engagement of the locking knobs ( 19 ... 59 ) having. Locking system according to claim 9, wherein on the groove of the wall area ( 2 ) is arranged a sealing ring which is adapted to a sealing connection between the lip portion ( 18 ... 58 ) or the locking nubs ( 19 ... 59 ) and the wall area ( 2 ) when the edge portion in the first bistable state inside or in the second bistable state outside against the wall area ( 2 ) presses.

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