EP0326052B1 - Method of making a pressure sealing between two chambers - Google Patents

Abstract

In a method of making a two-chamber pressurised package with an outer body which surrounds a pressurisable interior space and forms an opening, an inner body made of a material which forms folds or can be crumpled is inserted through this opening. Before flanging the opening or the like, filling the inner body and fitting a valve in the region of the mouth, the outer body and the inner body are connected to one another in a predetermined area and then folded over together to form a flanged rim. <IMAGE>

Description

The invention relates to a method for producing a two-chamber pressure pack with an outer body which encloses a pressurizable interior and has an opening with a flanged edge, an inner body made of fold-forming or crushable material being inserted through the opening of the outer body and being sealed in the opening area of the outer body is and a lid with valve is placed sealingly on the flanged edge of the outer body.

Such two-chamber pressure packs are generally used today as a replacement for the known pressure containers with propellant gas. The medium is discharged from the inner body by pressurizing the interior of the outer body. The medium to be dispensed therefore does not come into contact with this pressure medium, but is expressed by changing the inner body through a valve.

This known two-chamber pressure pack is known, for example, from US Pat. No. 3,974,945 and essentially consists of three parts, namely the outer body, for example an aluminum sleeve with a base, the inner body, for example a very thin aluminum sleeve and a funnel, which extends onto the mouth rim is placed on the inner and outer body and encloses it in a sealing manner. The corresponding valve is then inserted in the center of this disk-shaped funnel.

Attaching the funnel to the mouth edges of the inner and outer body means a considerable amount of work, since this has to be done by hand. The funnel is rolled or flanged together with the mouth edges. That is why he needs a certain place. Since the valve itself usually also requires a diameter of 25 mm, the openings of today's two-chamber pressure packs must have a total diameter of around 40-65 mm. In between, only two-chamber pressure packs with graduated dimensions are used.

From US-A 4 308 973, in turn, a two-chamber pressure pack is known, in which the edge of the funnel is crimped together with the mouth edge of the outer body. The inner body or its mouth edge is fixed to the outer body close to the flanged edge. Here there is a great risk that a leak will occur at this point, since the inner body is only glued to the inner wall of the outer body.

From FR-A 2 310 287 an outer body is known which already has a flanged opening edge. An annular flange of an inner body is then placed on this flanged opening edge and bent around this flanged edge. Significant sealing problems also arise here. Furthermore, this method is not for an inner body made of thin, crushable material Suitable as this material cannot form an opening flange and tears outwards when flared.

Similar problems also arise with a two-chamber pressure pack according to FR-A 2 342 222, according to which the opening edge of an inner body is also placed on a pre-flanged opening edge of an outer body. Here, the tightness is created only by introducing a sealing compound between the flanged edge of the funnel and the flanged opening edge of the outer body.

In EP-A 0 017 147 too, the edge of an inner vessel is bent outwards. Here, the dimensions of the inner container are chosen so that it lies against the inner wall of the jacket of the outer container or is at a very short distance. The outer container also has an outwardly bent edge on which the bent edge of the inner vessel is then supported. There is no connection between the outer container and the inner container here, the connection is only brought about by a valve funnel.

Finally, from FR-A 2 140 804, which is considered to be the state of the art, a two-chamber pressure pack is known in which an inner container clings closely to an outer container. The mouth opening is cylindrical, a valve funnel being butt-fitted onto the mouth opening. There are also significant problems with regard to sealing. In addition, inserting an inner container that closely fits the outer container is very difficult with the selected contours.

The inventor has set itself the goal of developing a method of the type mentioned above, by means of which the attachment of the additional funnel becomes superfluous, in which the interior of the outer body is kept absolutely tight can and with which two-chamber pressure packs with different opening diameters can be produced from 1 inch, ie from 25.4 mm.

To achieve this object, the outer body and the inner body, which has a substantially cylindrical shape, before the flanging or the like. The opening, before filling the inner body and before attaching a cover with a valve in the opening area and sealed together then be folded together to form a ring-shaped flange edge.

This means that a leak-free connection between the inner body and the outer body is established even before the flanged edge is produced, and the interior which can be pressurized is thus kept absolutely tight.

The connection is preferably carried out by welding, gluing, shaping or the like. The best solution has been found to be a coating which is applied either to the outer body or to the inner body or to both in the connection region before the inner body is inserted into the outer body. This coating, for example a suitable adhesive, can then dry so that the inner body is inserted into the outer body without changing the coating. After insertion, the two-chamber pressure pack preferably passes through an oven in which the coating is liquefied. This already creates a certain connection between the inner body and the outer body. However, since the inner body generally maintains a certain distance from the outer body in order to be surrounded by sufficient pressure medium in the position of use, it has proven to be advisable to insert a tool into the opening of the two-chamber pressure pack, via which the inner body in the corresponding connection area is pressed against the outer body. This tool can be heated so that the coating is liquefied or kept in motion by this heat.

After the connection between the inner body and outer body has been established, the mouth edges are then flanged, this preferably being done by rolling.

Now the interior is absolutely tight. If, contrary to expectations, leaks occur in the area of the connection, additional sealing material can be filled through the opening, which also serves to pressurize the interior, which then flows along the inner walls of the outer body and thus complements the coating of the connection area.

In the last step, the two-chamber pressure pack now only needs to be filled with the medium to be dispensed and the valve fitted, through which the space of the inner body is now sealed, as well as the propellant gas being supplied via a bottom hole.

This method according to the invention also has the advantage that both the outer body and the inner body can be printed, varnished or the like before the flanging. In addition, in contrast to the hoppers previously used, all standard interior protective coatings can be used. The flanging can be done by means of an automatic machine, so that considerable labor is saved.

Fig. 1

einen Längsschnitt durch eine erfindungsgemäße Zwekammer-Druckpackung in einem Vorstadium der Herstellung;

Fig. 2

einen weiteren Längsschnitt durch die Zweikammer-Druckpackung nach Fig. 1 in einem weiteren Stadium der Herstellung.

Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawing; this shows in

Fig. 1

a longitudinal section through a two-chamber pressure pack according to the invention in a preliminary stage of manufacture;

Fig. 2

another longitudinal section through the two-chamber pressure pack according to FIG. 1 in a further stage of manufacture.

A two-chamber pressure pack P according to the invention has a sleeve-shaped outer body 1, which in the present exemplary embodiment essentially consists of a cylinder jacket 2 and a base cover 3. This outer body 1 can, for example, be produced from an aluminum blank in the extrusion or deep-drawing process. The bottom cover 3 has a bore 4 through which the interior I can be pressurized. After this process, the bore 4 can be closed.

An inner body 6 is inserted into a cylinder opening 5 beyond the bottom cover 3 of the outer body 1. This inner body 6 also has a cylinder jacket 7 and a closed bottom cover 8. Overall, this inner body 6 consists of a relatively thin aluminum, so that it can be crushed with the formation of folds.

Cylinder jacket 7 and base cover 8 enclose a space R, which in the position of use serves to receive a medium to be dispensed.

In the present exemplary embodiment, the inner body 6 maintains a distance a from the cylinder jacket 2 of the outer body 1 over long distances. Towards the cylinder opening 5, i. H. in the mouth area of outer body 1 and inner body 6, however, inner body 6 or its cylinder jacket 7 is connected to cylinder jacket 2 in area b. The connection is made, for example, by welding, gluing, laser welding, shaping or the like.

This preliminary stage of a two-chamber pressure pack according to the invention is produced as follows:

The outer body 1 is drawn from an aluminum blank. The hole 4 is made in the bottom cover 3 and the cylinder jacket 2 is covered or welded with a coating 9 of an adhesive over the region b.

Then the inner body 6 is inserted, the coating 9 being solidified so that it does not hinder insertion.

The two-chamber pressure pack P now passes through an oven in which the coating 9 is liquefied. As a result, a connection between cylinder jacket 2 and cylinder jacket 7 is already initiated. However, the correct connection produces a heated tool which is inserted through the cylinder opening 5 and presses the cylinder jacket 7 in region b against the cylinder jacket 2.

The next processing stage is shown in FIG. 2. In this processing stage, on the one hand, the bottom cover 3 is deformed so that it can withstand an internal pressure in the interior I and does not bulge.

Furthermore, the cylinder jacket 2 and cylinder jacket 7 are flanged to the outside in the region of the cylinder opening 5, so that a flanged edge 10 with an annular cross section is produced. Here, cylinder jacket 2 and cylinder jacket 7 are simultaneously pulled inwards in a specific area.

In a further stage of production, the space R of the inner body 6 is now filled with the substance to be dispensed and the cylinder opening 5 is closed by a cover with a valve, not shown. This lid seals the flange 10. The interior I of the outer body 1 is then pressurized through the bore 4, the bore 4 then being closed. At the same time, however, the inner body 6 is pressurized, so that when the valve is actuated, the medium is discharged from the space R of the inner body 6 through the valve, while the inner body 6 yields to the same extent to the pressure in the interior of the outer body 1 and crumples .

If it turns out that there are leakages in the area of the coating 9 when the interior I of the outer body 1 is pressurized, it is possible to introduce further sealing material into the interior I through the bore 4. This flows along the cylinder jacket 2 to the coating 9, so that leaks can also be eliminated subsequently.

Claims (7)

1. Process for the production of a dual chamber pressure packing with an external body which surrounds a pressure-loadable internal space and has an opening with a curled rim, wherein an internal body of fold-forming or creasable material is inserted through the opening in the external body and is sealed against the external body in the opening region of the external body and wherein a cover with valve is placed in a sealing manner onto the curled rim of the external body, characterised in that the external body and the internal body, which has a substantially cylindrical form, are connected to one another in the opening region before curling or the like of the opening, before filling of the internal body and before application of the cover with valve and are then turned down together to form a curled rim of annular cross section.
2. Process according to claim 1, characterised in that the connection is made by welding, adhesion, deformation or the like.
3. Process according to claim 1 or 2, characterised in that the external body and/or the internal body are provided with a coating in the connecting region before insertion of the internal body.
4. Process according to claim 3, characterised in that, after insertion of the internal body but before curling, the dual chamber pressure packing passes through an oven in which the coating is liquefied.
5. Process according to claim 3 or 4, characterised in that a heated tool which presses the internal body against the external body in the connecting region is introduced into the opening in the dual chamber pressure packing.
6. Process according to at least one of claims 1 to 5, characterised in that packing material is introduced into the internal space of the external body before or during the pressure loading of the internal space of the external body.
7. Process according to at least one of claims 1 to 6, characterised in that the curled region is produced by deformation.

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