EP0791538B1 - Method and device for closing a metallic container - Google Patents

Abstract

The method involves closing a metal container (1) by a lid (10) which has a bottom (11), a side wall (12) and a rim (13). A sealing joint (17) is placed in the rim on periphery of the container opening (16). The lid is placed on the container by applying a pressure on it in order to crush the joint between the container and the rim. The joint is then locked by stamping the lid side wall onto the container. The lid is stamped onto the container on segments divided along the container perimeter. Stamping of the lid side wall is also made onto the large walls of the container.

Description

The present invention relates to shaped metal containers whatever, for example truncopyramidal, and intended to contain painting in particular. After filling, these containers are typically closed by a lid.

The invention relates more particularly to a method of closing such containers. It also relates to a machine for the implementation of this process.

In a known manner, the truncopyramidal or cylindrical containers are closed with a lid with legs, perpendicular to the plane of the lid.

A container of this type is described in document FR-2 248 097.

After filling the container, the lid is placed on it last, a seal being placed between the container and the lid, at the periphery of the opening of the container. There is pressure on the cover to compress the seal and this pressure is maintained in blocking the legs, under the edge of the container.

This closure brought satisfaction to users during many years.

However, the lid is relatively difficult to remove. He is in indeed, it is necessary to lift each tab to disengage the cover, this which is tedious. Moreover, when we want to put back in place the cover, it is difficult to seal the closure.

Finally, the presence of the legs is unattractive.

Another metal container is known from GB-A-2,033,880. This container has a lid attached to the container by means of a deformation of the only lid. To this end, the edge of container is provided with a stapling reinforcement. We fix the lid by stamping the single lid to a level just below the reinforced edge of the container.

It appeared necessary to develop a new process for closure that overcomes the disadvantages mentioned above.

The subject of the invention is thus a method of closing a metal container with a lid having a bottom, a wall side and a flange, according to which a gasket is placed in periphery of the opening of the container and the lid being placed on the container, apply a pressure on the lid to crush the seal between the container and the rim of the lid,

According to the invention, the lid is fixed on the container in embossing the wall of the lid and the wall of the container which causes deformation of these walls to the outside of the container.

Advantageously, the lid and the wall of the container are stamped at points or segments distributed around the periphery of the container.

When the opening is of substantially rectangular shape, the stamping is preferably carried out in each corner of the container.

In this case, a stamping of the side wall of the lid on the container is advantageously made in the large walls of the container and, preferably, substantially in the center of these walls, when the nature of the product contained in the container requires it.

Preferably, when the opening of the container is of a shape substantially round, the stamping of the lid on the container is realized in regularly distributed points or segments.

The rim of the lid advantageously has a concavity turned towards the bottom of the lid, in which said seal is placed seal and ends with an edge rolled outward from the lid.

The invention also covers the implementation of the method of closing by means of a machine.

This machine comprises means for applying a force of compression on the lid when this one is in place on the container and means to achieve stamping the lid on the container.

• la figure 1 est une vue de côté d'un récipient troncopyramidal, fermé par un couvercle selon l'état de la technique,
• la figure 2 représente une demi-vue en coupe d'un exemple de couvercle pour la mise en oeuvre du procédé de fermeture selon l'invention,
• la figure 3 comporte les figures 3a à 3c qui sont des vues partielles en perspective, avec une section droite vue en coupe, d'un exemple de couvercle et d'un récipient dans les trois étapes du procédé de fermeture selon l'invention
• la figure 4 est une vue partielle en perspective, avec une section droite vue en coupe, d'un récipient fermé avec un couvercle selon le procédé de fermeture de l'invention, un outil étant en place pour l'ouverture du récipient, et
• la figure 5 comporte les figures 5a et 5b qui sont des vues schématiques partielles et en coupe d'un exemple de machine pour la mise en oeuvre du procédé de fermeture selon l'invention.

The invention will be better understood and other objects, advantages and characteristics thereof will appear more clearly on reading the description which follows, made with reference to the accompanying drawings which show non-limiting examples of embodiment of the invention and on which ones:

• FIG. 1 is a side view of a truncopyramidal container, closed by a lid according to the state of the art,
• FIG. 2 represents a half-sectional view of an exemplary cover for implementing the closure method according to the invention,
• FIG. 3 comprises FIGS. 3a to 3c, which are partial perspective views, with a sectional cross-section, of an exemplary cover and a container in the three stages of the closure process according to the invention;
• FIG. 4 is a partial perspective view, with a cross section in cross-section, of a closed container with a lid according to the closure method of the invention, a tool being in place for opening the container, and
• FIG. 5 comprises FIGS. 5a and 5b which are partial schematic and sectional views of an exemplary machine for implementing the closure method according to the invention.

The elements common to the different figures will be designated by the same references.

FIG. 1 shows a known truncopyramidal container, having a bottom 2 and near the latter, a ring 3.

Such a container may also include a rod 4, at least in the corners, to allow separation easily stacked containers. A handle 5 can also to be planned.

The container 1 is closed by a lid 6 conventionally used so far. It has a background, no shown in Figure 1, and a rim 7 which extends by a series of legs 8 substantially perpendicular to the bottom plane of the lid. The free edge 9 of the legs is returned to the outside.

The lid 6 is fixed on the container 1 by blocking the legs 8 under the edge of the container. A seal sealing, not shown in Figure 1, is provided between the container 1 and the lid 6, on the periphery of the opening of the container.

With reference to FIG. 2, an example of a cover 10 for the implementation of the closure method according to the invention essentially comprises: a bottom 11, a side wall 12 and a rim 13 whose concavity is turned towards the bottom 11. The ledge ends with a edge 14 rolled towards the outside of the lid. This rolled edge gives a point of stiffness when opening the container.

The lid 10 does not include any fixing lug, this and the rolled edge 14 which defines the periphery of the lid.

Preferably, a recess 30 is provided in the side wall 12 of the cover 10. This recess is advantageously provided to allow a good stackability of the lids upon delivery and facilitate the automatic distribution of lids.

Figures 3a to 3c will illustrate the closing method according to the invention.

Figure 3a partially shows a container 1 classical metal, for example of shape frustopyramidal. It has a free edge 15 rolled towards the inside of the container and a ring 4 to facilitate the separation of the stacked containers.

This container 1 has not undergone any modification by compared to known containers. Moreover, as we will see later, the closing process according to the invention applies to shaped containers any, and in particular to cylindrical containers.

The container 1 is of the full opening type, that is to say no element is present inside the container, at the level of its opening. With this guy the inner edge of the container is not likely to retain some of the material contained in the container and so it is easily cleaned. This facilitates subsequent recycling of the container.

In the step of implementing the method illustrated in FIG. 3a, the lid 10 according to the invention is place in the opening 16 of the container, a seal sealing 17 being placed in the concavity of the rim 13. This step ends when the seal 17 comes into contact with the rolled edge 15 of the container 1.

Figure 3b shows the next stage of implementation of the method according to the invention, in which the seal seal 17 is compressed by exerting a force represented by the arrow F in one direction substantially parallel to the walls of the container and directed towards its bottom.

The last stage of implementation of the method of closing is illustrated in Figure 3c.

During this step, the force F is maintained for keep the seal 17 compressed and the lid 10 is fixed on the container by stamping the wall 12 of the cover 10 and the wall 18 of the container 1 which causes deformation of these walls, outwards of the container. This stamping is done in points 19 appropriately distributed, applying force represented by the arrow F1, in one direction substantially parallel to the bottom 11 of the container and directed from inside the container to its wall 18.

Thus, the method according to the invention ensures the closing the container with a lid thanks to stamping the latter directly on the container, without any other means of closure being necessary.

The points 19 stamping are distributed so appropriate, depending on the shape of the container.

In the case of a container of truncopyramidal shape, the stamping points are preferably made in each of the four angles. Indeed, the corners are the most rigid parts. Moreover, the container wall is, in general, slightly arched in these areas and these stamping points contribute then to ensure the tightness of the container.

For this type of container, depending on the nature of the product it contains, it may be necessary to make stamping points on the long sides of the container. This is particularly the case when the pressure the product contained in the container evolves after filling (eg hot or degassing product). These stamping points then ensure a good support of the lid.

In the case of a cylindrical container, the wall has a stiffness substantially identical in every respect. The stamping points can thus be distributed regularly around the container.

Preferably, the stamping is carried out according to segments, for example consisting of connected points between them. This makes it possible to increase the holding of the closure. By elsewhere, the lid can easily snap into segments, after opening the container. Indeed, stamping segments are more regular and accurate than points.

The closure obtained by the process according to the invention has been the subject of numerous checks. Tests performed have established that this closure presents the level of commonly required quality, as far as tightness and resistance to falling.

Moreover, the method according to the invention makes it possible to modulate the quality of the closure. The tightness of the closing is achieved by crushing the joint. The compression that allows to crush the seal is set to that the sealing is ensured in all cases. By against, during the implementation of the process according to the invention, stamping can be adjusted in such a way that the container has more or less resistance important to shocks and internal pressure.

The cover 10 used for the implementation of the method according to the invention has only one edge rolled, on the outskirts. No bracket is necessary to ensure the closure of the container, which improves the aesthetics of the closed container.

Figure 4 shows how to open a container previously closed with the method according to the invention.

The tapered end 21 of a tool 20, of the type screwdriver, is first introduced under the rim 13 of the lid 10.

The handle 22 of the screwdriver 20 is then turned around of its axis, which causes the lifting of the lid.

Preferably, when the container has corners, the screwdriver 20 is inserted under the rim 13 at corner or corner level. Since a corner is unlocked, the lid opens completely.

The opening of the container can thus be carried out in a single operation. This is an advantage considerable compared to closed containers so classic, such as that illustrated in Figure 1, opening can only be achieved by lifting each paws. The opening of such containers therefore requires as many operations as legs, which is tedious for the user.

Moreover, when the user wishes to close the container, he just need to re-insert the lid 10 in the opening 16 of the container. This reinstatement is easily done, ensuring a good seal.

This is another advantage of the lid obtained by the process according to the invention, compared with closed containers so as shown in Figure 1. After opening, the lid can be replaced on the opening of such container but it does not seal in the as each tab 8 of the lid 6 is again blocked under the rim of the lid. These operations are never, in practice, realized by the users. The container is therefore no longer watertight, after opening, this which usually leads to the degradation of the product contains.

Reference is now made to Figure 5 which shows a machine example, for the implementation of the closure process according to the invention.

Figure 5a corresponds to the process step of closure, illustrated in Figure 3b.

The machine 23 comprises a plate 24 having a recess 25 at the periphery. Dimensions and shape the plateau and the offset are chosen in such a way that that the lower part 26 of the tray gets into the opening 16 of the container, while the recess 25 bears on the rim 13 of the lid 10.

Means not shown in Figure 5a are then actuated to press the tray 24 on the container. The compression force is illustrated by the arrow F. The value of this force is chosen so as to guarantee the seal whatever the thickness of the seal Sealing 17.

The machine 23 also comprises means 26 for achieve the stamping points 19 or segments. The means 26 are constituted by a plurality of punches 27 fixed on arms 28, themselves pivotally mounted on the plateau 24, around an axis parallel to the plane of the plateau. In FIG. 5b, only one arm 28 and one punch 27 are shown, the arm 28 being pivotally mounted around the axis 29.

The machine 23 has as many punches 27 as there are stamping points 19 provided. An arm 28 can carry a or more punches.

With reference to Figure 5b which corresponds to the last step of the closure process, illustrated in 3c, the machine 23 maintains the compression force F and the stamping means 26 are actuated for make a stamping in 19. For this, the means 26 pivot about the axis 29 and the punch 27 then exerts in 19 a force represented by the arrow F1.

Preferably all points or segments stamping are performed simultaneously, by actuating suitably the stamping means 26.

As mentioned above, the importance of locking can be adjusted by changing the number of stamping points or segments, in particular to meet the requirements of the product contained by the container.

The reference signs inserted after the technical characteristics mentioned in the claims are only intended to facilitate the understanding of the latter and in no way case in limiting the scope.

Claims (7)

1. Method for sealing a metal container (1) with a lid (10) comprising a bottom (11), a side wall (12) and a rim (13), in which method a seal (17) is placed around the periphery of the opening (16) of the container, and when the lid (10) is placed on the container (1), pressure is applied to the lid (10) to collapse the seal (17) between the container (1) and the rim (13) of the lid, characterized in that the lid (10) is fixed into the container (1) by stamping the side wall (12) of the lid (10) and the wall (18) of the container (1) while giving outer the container (1) a deformation of said walls (12,18).
2. Sealing method according to Claim 1, characterized in that the lid (10) and the wall (18) are stamped at points (19) or segments that are distributed around the perimeter of the container.
3. Sealing method according to one of Claim 1 or 2, the opening (16) of the container being substantially of rectangular shape, characterized in that stamping takes place in each corner of the container.
4. Sealing method according to Claim 3, characterized in that the side wall (12) of the lid is stamped into the container (1) also along the long walls of the container and, preferably substantially in the middle of these walls.
5. Sealing method according to one of Claim 1 or 2, the opening (16) of the container being substantially of round shape, characterized in that the lid (10) is stamped into the container (1) at uniformly spaced points (19) or segments.
6. Sealing method according to one of Claims 1 to 5, characterized in that the rim (13) of the said lid (10) is concave facing towards the bottom (11) of the lid, the said seal (17) being placed in this concave part, and ends in an edge (14) rolled towards the outside of the lid.
7. Method according to anyone of Claims 1 to 6, characterized in that it is inplemented with a machine comprising means (24) for applying a compression force to the lid (10) when the lid is in place on the container (1), and also means (26) for stamping the lid (10) into the container (1), while giving outside the container (1) a deformation of both the wall (12) of the lid (10) and the wall (18) of the container (1).

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