GB1596939A

GB1596939A - Hermetically closed packaging container

Info

Publication number: GB1596939A
Application number: GB4835/78A
Authority: GB
Original assignee: Schmalback Lubeca AG
Current assignee: Ardagh Metal Packaging Germany GmbH
Priority date: 1977-02-08
Filing date: 1978-02-07
Publication date: 1981-09-03
Also published as: BE863755A; DE7703653U1; FR2379449B1; NL7801467A; LU79032A1; FR2379449A1; IT7820056A0; CH631934A5; IT1092431B

Abstract

In the present hermetic closure of the metal cap (3) of a plastic container (2), the cap material is many times thinner than the material of the container (2). The rim (11) of the cap (3) grips in a positive-locking manner around the outwardly thickened flange (6, 7) of the container (2) and its free edge (13) is pressed from the outside approximately radially into the material of the container wall. The transition point (10) of the cap (3) between the cap face (8) and the core wall (9) is pressed into the material of the inside of the container wall, thus resulting, with the gripping of the flange (6, 7), in a firm and hermetic closure. An insert part (21) may be arranged in a positive-locking manner between the cap (31) and the flange (23) or neck (22) of the container (20). <IMAGE>

Description

(54) HERMETICALLY CLOSED PACKAGING CONTAINER (71) We SCHMALBACH-LUBECA G.m.b.H., of Schmalbachstr. 1, Postfach 3307, D-3300 Braunschweig, Germany; a German body corporate do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement The present invention relates to a hermetically closed packaging container comprised of a plastics material container body and a metal end, in which the end is connected to the container body by a crimping operation.

Numerous packaging containers are already known comprised of a plastics material container body and a metal end. As far as the end is not adapted for screwing on, the edge of the end is connected to the edge of the container body by means of a crimping operation. A part of the outer edge section of the end may thus be bent inwards or rolled inwards forming an annular double edge (see German Gebrauchsmuster No.

7 037 267).

It is further known to abut the chuck wall of the end from the inside against the inner surface of the substantially smooth body wall of the container and to press the flanged edge of the end inwardly, after embracing the aperture edge from the outside, against the outer surface of the body wall, so that the body wall in a radial direction is pressed between the chuck wall and the flanged edge.

Known connections between a plastics material container body and a metal end do not pose any problems in the case in which the wall thickness of the body of the container and the thickness of the metal end correspond substantially to one another.

Considerable problems do exist when the two wall thicknesses differ substantially from one another and when the wall thickness of the container body is a multiple of the wall thickness of the sheet metal end. In these cases, adequate hermetic closing at the connecting point can no longer be attained by known flanging or folding operations.

It is an object of the present invention to provide a hermetically closed packaging container of the kind referred to in detail above which is of simple structure and also ensures a reliable hermetic closure when the wall of the plastics material container body is of a substantially larger wall thickness than the thickness of the metal end.

According to the present invention there is provided a hermetically closed packaging container comprised of a plastics material container body and a metal end, in which the end is connected to the container body by a crimping operation, in which the thickness of the wall of the container body is substantially greater than the thickness of the metal end, the wall of the container body having an outwardly projecting radial flange, the metal end having a flange which positively embraces the outwardly projecting radial flange of the wall of the container body circumferentially with axial and radial compression, and in which the edge portion of the flange of the metal end is embedded in the material of the wall of the container body.

The metal end has a chuck wall and preferably the portion of the metal end between the end flange and the chuck wall is pressed at least partially into the inside surface of the material of the container wall.

Further preferably, the flange of the wall of the container body has a bead-shaped edge and the edge portion of the end flange is bent radially inwards at approximately right angles to the container axis beneath the bead and the end flange embraces circumferentially the bead region of the container edge with axial and radial compression.

Desirably, the outer edge of the bent over edge portion is embedded to a depth equal to a fraction of the wall thickness of the containter in the container wall. The penetration depth of the outer edge region in the container wall preferably substantially corresponds to 2 to twice the sheet metal thickness.

The flange-shaped edge portion of an insert may be positively clamped with a hermetical closing effect between the toD portion of the end flange of the metal end and the flanged or bead-shaped edge of the container.

Tests have shown that the new packaging container supplies an optimal hermetic closure. It is hence particularly favourable that the package is hermetically closed with conventional tools in which in the region of the operating position a counter-hold engages radially from the inside the chuck wall of the end, whilst a profiled sealing roller engages the edge of the end on the outside ensures the flanging and axial and radial compression of the edge regions of the end.

The present invention will be further illustrated, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a vertical fragmentary section through the edge region of a packaging container in accordance with the invention; Fig. 2 is a vertical fragmentary section of the edge region of a plastics material container of a hermetically closed packaging container in accordance with the invention and the edge region of an insert projecting into the container and to be connected therewith, and which is also made of a plastics material; and Fig. 3 shows, on an enlarged scale, a verti cal section through the edge region of the packaging container of Fig. 2 after being hermetically closed.

The hermetically closed packaging container shown in Fig. 1 in section comprises a container body 2 formed of a plastics material and a metal end 3.

The container body 2 has a substantially cylindrical section 4 of considerable wall thickness 5, and, at its end section 6, an outwardly projecting radial flange having a bead-shaped edge.

The end 3 is made of sheet metal and has a thickness 19 substantially less than the wall thickness 5 of the container body 2.

The metal end preferably may comprise a conventional tear-open end. The metal end has an end panel 8 which by means of a small radius 10 merges directly into a substantially cylindrical chuck wall 9 where it is adjoined in the upper region by an edge flange 11.

Fig. 1 shows the parts already in the hermetically closed state. During closure, the flange 11 positively embraces the outwardly projecting radial flange 7 in the end section 6 of the container body circumferentially with axial and radial compression. The edge portion 12 of the end flange 11 is bent radially inwards at approximately rightangles to the container axis beneath the flange 7, as indicated in Fig. 1 by the arrows P.At the same time, the chuck wall 9 and the outer edge 13 of the bent over edge portion 12 of the metal lid are pressed radially together with radial squeezing of the upper section of the cylindrical section 4 of the container body 2, and thus in such a manner that the chuck wall 9, at least in the region 15 of the radius of curvature 10, is pressed at least partially into the inside surface of the material of the container wall, whilst the outer edge 13 is embedded in the outer surface of the container wall by a depth equal to a fraction of the wall thickness 5. The depth of engagement of the outer edge 13 is indicated by 14.The penetration depth of the chuck wall 9 in the inside surface of the material of the container wall at point 15, at the most amounts to a single sheet metal thickness 19, whilst the penetration depth 14 of the outer edge 13 in the outer surface of the container wall amounts to from l to twice the sheet metal thickness 19, preferably a single metal thickness.

In this embodiment of the hermetic closure, the whole upper region 6 and 7 of the container edge is clamped from all sides under pressure between the sections of the end positively enclosing this region, so that despite the substantial difference in thickness between the container material and the end material, a mechanically reliable and hermetic closure connection between the parts is obtained.

As illustrated in Figs. 2 and 3, the container body 20, in the region of the end face, has an outwardly projecting radial flange 23. The container body 20 is made of a plastics material and has a substantially cylindrical section 22 of considerable wall thickness, which at the upper free end merges into the flange 23.

In this embodiment, it is assumed that the container body 20 has an insert 21, preferably also made of a plastics material, associated therewith, which is so formed that a wall section 27 close to the aperture 28 of the insert engages with a tight fit in the upper region of the container 20, whereby a flange-shaped edge portion 25 projecting outwards and enclosing the aperture 28 abuts against the end face of the container flange 23 as evident from Fig. 3.

Fig. 3 shows the mutual position of the parts in a hermetically closed state. Herein, for the connection of the container body 20 and the insert 21 and for hermetically closing the packaging 30, a metal end 31 is used, preferably a tear-open end. The latter in tum has an end panel 32 and a chuck wall 33 and a securing flange 34 which, as in the embodiment of Fig. 1, positively embraces the radially outwardly flanged edges 23 and 25 of the container 20 and the insert 21, circumferentially with axial and radial compression. The edge portion 35 of the flange 34 is bent radially inwards beneath the two bead edges 23 and 25. The free outer edge 36 is pressed into the container wall 22, whilst the chuck wall 33, at least at the trans ition point to the lid face 32 is pressed into the inner surface of the upper wall section 27 of the insert 21 at 38.

The production of the hermetic closure between the said parts may be effected in a conventional manner with a counter holder 40 engaging the end 31, which holder, with a circumferential projection 41, supports the chuck wall 33 substantially over the whole axial height from the inside, and is also adapted to be provided with a flanging tool 42 engaging on the outside and, on account of the profiling, is suitable to deform the edge flange 34 of the end with axial and radial compression.

This not only ensures a mechanically secure connection between the container body and the insert and the sheet metal end, but also ensures a hermetic closure between all parts.

WHAT WE CLAIM IS: 1. A hermetically closed packaging container comprised of a plastics material container body and a metal end, in which the end is connected to the container body by a crimping operation, in which the thickness of the wall of the container body is substantially greater than the thickness of the metal end, the wall of the container body having an outwardly projecting radial flange, the metal end having a flange which positively embraces the outwardly projecting radial flange of the wall of the container body circumferentially with axial and radial compression, and in which the edge portion of the flange of the metal end is embedded in the material of the wall of the container body.

2. A packaging container as claimed in claim 1, in which the metal end has a chuck wall and the portion of the metal end between the end flange and the chuck wall is pressed at least partially into the inside surface of the material of the container wall.

3. A packaging container as claimed in claim 1 or 2, in which the flange of the wall of the container body has a bead-shaped edge and in which the edge portion of the metal end flange is bent radially inwards at approximately right angles to the container axis beneath the bead and the end flange embraces circumferentially the bead region of the container edge with axial and radial compression.

4. A packaging container as claimed in claim 3, in which the outer edge of the bent over edge portion is embedded to a depth equal to a fraction of the wall thickness of the container body in the container wall.

5. A packaging container as claimed in claim 4, in which the penetration depth of the outer edge region in the container wall substantially corresponds to 21 to twice the sheet metal thickness.

6. A packaging container as claimed in any preceding claim, in which the flangeshaped edge portion of an insert is positively clamped with a hermetical closing effect between the top portion of the end flange of the metal end and the flanged edge of the container.

7. A hermetically closed packaging container, substantially as hereinbefore described with reference to and as illustrated in Fig. 1 or Figs. 2 and 3 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. ition point to the lid face 32 is pressed into the inner surface of the upper wall section 27 of the insert 21 at 38. The production of the hermetic closure between the said parts may be effected in a conventional manner with a counter holder 40 engaging the end 31, which holder, with a circumferential projection 41, supports the chuck wall 33 substantially over the whole axial height from the inside, and is also adapted to be provided with a flanging tool 42 engaging on the outside and, on account of the profiling, is suitable to deform the edge flange 34 of the end with axial and radial compression. This not only ensures a mechanically secure connection between the container body and the insert and the sheet metal end, but also ensures a hermetic closure between all parts. WHAT WE CLAIM IS:

1. A hermetically closed packaging container comprised of a plastics material container body and a metal end, in which the end is connected to the container body by a crimping operation, in which the thickness of the wall of the container body is substantially greater than the thickness of the metal end, the wall of the container body having an outwardly projecting radial flange, the metal end having a flange which positively embraces the outwardly projecting radial flange of the wall of the container body circumferentially with axial and radial compression, and in which the edge portion of the flange of the metal end is embedded in the material of the wall of the container body.