DE20000486U1 - Cap for a can - Google Patents

Description

Cap for a can

The innovation relates to a closure cap for a can, in particular a beverage can according to the preamble of claim 1.

DE 295 11 285 Ul discloses a closure lid for tin cans, which is formed by a base and a wall formed on the edge. The wall overlaps a bead on the outside of the can by means of an undercut, so that the closure lid is securely held to the can. If gas escapes from the can, in particular carbon dioxide from a carbonated beverage, the lid is lifted by the pressure of the gas, allowing the gas to escape. However, this leads to an undesirable loss of carbon dioxide.

The innovation is based on the task of creating a closure cap of the type mentioned above, which ensures a gas-tight closure of the can.

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This problem is solved according to the innovation with the features of claim 1.

The closure cap according to claim 1 has a cap base onto which a peripheral wall is formed. This wall has an undercut on the inside which is adapted to the outer contour of the bead. This design of the closure cap ensures that the closure cap is held securely on the bead of the can, so that the closure cap cannot be lifted, in particular by gas escaping from the can. To seal the closure cap to the can, a lip is provided which rests on the inside of the bead of the can. The outer contour of the bead thus remains free to engage the wall, so that the locking and sealing of the closure cap is carried out by different means. This is important because this is the only way to achieve an optimal seal. In particular, the wall and the lip can be optimally adapted to their respective function by making them from different materials or with different wall thicknesses. The fact that the lip is placed on the inside of the can's bead also ensures that damage to the bead has no negative impact on the sealing effect of the closure cap. If the can falls to the floor during transport, for example, or is struck with a hard object, notches will appear on the outside or on the upper edge, making it impossible to seal these surfaces. In contrast, the inside of the bead is protected against damage due to its special position.

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protected from external forces, so that it is not damaged under any circumstances. Finally, the tightly fitted cap protects against insects, which like to get into the can when it is open and cause unpleasant effects when drinking.

In order to make it easier to place the closure cap on the can, the ring diameter of the lip is reduced towards the free end according to claim 2. The free end of the lip therefore has a smaller diameter than the inner contour of the bead, so that the closure cap can be easily placed on the bead. In addition, the closure cap is sufficiently guided with its outer wall on the outer contour of the bead so that the lip is correctly aligned with the bead.

To further facilitate the placement of the closure cap onto the bead of the can, the lip is curved in cross-section according to claim 3. In addition, this ensures that the sealing lip rests flatly on the inner contour of the bead, so that a sufficient sealing effect is achieved even under unfavorable conditions.

In order to ensure that the closure cap is adequately fixed to the can on the one hand and to achieve a favorable sealing effect of the lip against the bead on the other hand, it is advantageous if the lip is more elastically deformable than the wall. This is advantageously achieved according to claim 4 by the lip having a smaller wall thickness than the wall. Al-

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Alternatively or additionally, it is also conceivable to make the lip from a softer material than the wall. For example, the wall could be made from a polymer and the lip from a corresponding polymer foam of the same base material. If the lip is thin at its free end according to claim 5, this results in a particularly favorable elastic deformability of the lip. This in turn improves the sealing effect of the closure cap against the can. The lip is preferably thinner than approx. 0.1 mm in the end area.

To further improve the sealing effect, it is advantageous according to claim 6 to pre-stress the lip against the inner surface of the bead by elastic deformation. However, this pre-stress must remain so low that the lip is only compressed radially without forming a fold or corrugation. Otherwise there would no longer be any sealing effect.

In order to be able to easily remove the closure cap from the can, a handle is held on the cap base according to claim 7. This is preferably formed integrally on the cap base and is ring-shaped. To achieve a favorable leverage effect, the handle projects radially over the cap base, which makes it easier to remove the closure cap from the can.

According to claim 8, polypropylene has proven to be the base material for the closure cap, as it is food-safe and can be produced with a very smooth surface. In addition, polypropylene can be

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easy to process using injection molding, which keeps the manufacturing costs of the closure cap low. In addition, polypropylene is sufficiently temperature-resistant so that the closure cap is dishwasher-safe. Polypropylene foam has proven to be a good choice for forming the lip, so that the closure cap and the lip can be made as one piece. In this case, the lip is simply molded onto the base of the cap, and because the polymer is the same, there are no adhesion or connection problems.

The subject matter of the innovation is explained by way of example using the drawing, without limiting the scope of protection.

It shows:

Figure 1 is a view of a closure cap according to the invention from below,

Figure 2 is a sectional view through the closure cap according to Figure 1 along the section line II-II and

Figure 3 shows an enlarged section of the closure cap according to Figure 2.

A closure cap 1 is essentially rotationally symmetrical and has a cap base 2. A substantially cylindrical wall 3 is formed on the edge of the cap base 2, which grips a bead 4 of a beverage can 5 on the outside. In order to ensure a sufficiently

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In order to ensure that the closure cap 1 is held securely on the bead 4, this wall 3 has an undercut 6 on the inside which is adapted to the outer contour 7 of the bead 4. If gas, in particular carbon dioxide, flows out of an opening 8 of the can 5, the resulting gas pressure cannot lift the closure cap, which instead remains in the position shown in Figure 2.

To seal the closure cap 1 against the can 5, a ring-shaped lip 9 is provided. This seals against the conically upwardly widening inner surface 7a of the bead 4 of the can 5. The ring diameter 10 of this lip 9 decreases towards the free end 11. This ensures that the closure cap 1 can be easily placed on the bead 4 of the can 5 without the lip 9 being compressed at the upper edge 12 of the bead 4. To ensure that the lip 9 has sufficient elasticity, its wall thickness 13 is significantly less than the wall thickness 14 of the wall 3. In addition, the wall 3 and the cap base 2 are made of polypropylene, while the lip 9 is made of closed-cell polypropylene foam. Polypropylene foam has better elasticity than polypropylene, so that the lip 9 is much more deformable than the wall 3, which only serves to lock the closure cap 1 to the can 5.

A radially projecting handle 15 is also provided on the cap base 2, which is provided with an opening 16. This opening 16 is dimensioned such that a

Finger can easily be pushed through this opening 16. This allows the closure cap 1 to be easily removed from the can 5.

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List of reference symbols

1 cap

2 Cap base

3 Wall

4 bead

5 can

6 Undercut

7 Outer contour of the bead

7a inner sealing surface of the bead

8 Opening the can

9 Lip

10 ring diameter

11 free end of the lip

12 Upper edge of the bead

13 Wall thickness of the lip

14 Wall thickness

15 Handle

16 Opening the handle

Claims (8)

1. Closure cap for a can ( 5 ), in particular a beverage can ( 5 ), which has an annular, upwardly bent bead ( 4 ) to which the closure cap ( 1 ) can be fixed in a sealing manner, which has a cap base ( 2 ) on the edge of which a wall ( 3 ) is formed, which overlaps the bead ( 4 ) of the can ( 5 ) on the outside and is provided with an undercut ( 6 ), wherein sealing means (9) which engage the bead ( 4 ) of the can ( 5 ) are formed on the closure cap ( 1 ), characterized in that the sealing means ( 9 ) are formed by at least one annular lip ( 9 ) which presses against the inner surface ( 7a ) of the annular bead ( 4 ) and which is formed within the wall ( 3 ) on the cap base ( 2 ) are formed, and that the undercut ( 6 ) is adapted to the outer contour ( 7 ) of the bead ( 4 ). 2. Closure cap according to claim 1, characterized in that the ring diameter ( 10 ) of the lip ( 9 ) is reduced towards its free end ( 11 ). 3. Closure cap according to claim 1 or 2, characterized in that the lip ( 9 ) is curved when viewed in cross section at least in the area where it rests on the bead ( 4 ). 4. Closure cap according to at least one of claims 1 to 3, characterized in that the lip ( 9 ) has a smaller wall thickness ( 13 ) than the wall ( 3 ) and/or consists of a softer material. 5. Closure cap according to at least one of claims 1 to 4, characterized in that the lip ( 9 ) has a thin film thickness at its free end ( 11 ). 6. Closure cap according to at least one of claims 1 to 5, characterized in that the lip ( 9 ) is prestressed by elastic deformation against the inner surface ( 7a ) of the bead ( 4 ). 7. Closure cap according to at least one of claims 1 to 6, characterized in that a handle ( 15 ) is held on the cap base ( 2 ). 8. Closure cap according to at least one of claims 1 to 7, characterized in that the cap base ( 2 ) and the wall ( 3 ) are made of polypropylene and the lip ( 9 ) is made of polypropylene foam.