WO1996024528A1

WO1996024528A1 - Container end

Info

Publication number: WO1996024528A1
Application number: PCT/GB1996/000109
Authority: WO
Inventors: Philippe Cochet
Original assignee: Carnaudmetalbox Plc; Carnaudmetalbox S.A.; Carnaudmetalbox N.V.
Priority date: 1995-02-06
Filing date: 1996-01-23
Publication date: 1996-08-15
Also published as: ZA96895B; FR2730214A1; AU4397896A; FR2730214B1; EP0808280A1

Abstract

A container end (11) for a container for liquid products having a planar end panel with raised bosses (13a, 13b). The absence of any countersink prevents build up of liquid deposit on the end and the bosses allow the end to be centred for seaming.

Description

"CONTAINER END"

This invention relates to a container end. In particular it relates to a container end such as a metal can end having a pouring aperture and a method and apparatus for manufacture of a three piece container having such an end.

Three piece metal cans which have a pouring aperture are widely used for the packaging of liquids and particularly for liquid food products. Cans with pouring apertures are often used for concentrated food products such as milk and fruit juice which are not always consumed or completely emptied out of the container immediately after opening.

Conventionally, three piece cans compromise a cylindrical can body to which two ends are fixed, typically by seaming. Each end comprises a countersunk panel having a curled edge to facilitate seaming to each end of the can body. One end is provided with opening means and may be an easy open end, with an opening ring fixed to the end which breaks a score on the end with its nose when the ring is raised. Alternatively, a heat sealed diaphragm or plug may be used to close an aperture made in the end, or the opening may be made by the consumer.

When the can is opened, product is dispersed by pouring. When the can is returned to the upright position, some deposit of product inevitably remains at the edge of the end, typically in the countersink at the immediate proximity of the curl. When the product is not completely poured out after opening, this deposit will have solidified when the consumer next wishes to pour some of the product. Since this solidified deposit takes on an appetising colour it is often regarded as being suspect by the consumer.

This invention seeks to overcome this problem of accumulation of dried product in the countersink at the edge of the container.

According to the present invention there is provided a container end comprising an end panel having a curled edge, characterised in that the curled edge depends from a substantially planar end panel and the end panel further includes at least one raised boss adapted to engage a locating chuck.

The end of the invention thus has no countersink in which a deposit of product can collect. The absence of any countersink would be expected to create a problem in locating the end on a container body but in the present invention the boss or bosses are used to engage a locating chuck, thus enabling ease of delivery and centring of the end of the body.

Preferably, the end further comprises opening means which may be fixed to the end panel.

The boss or bosses are usually symmetrical about the centre of the end. Advantageously, there are two bosses, one on either side of the centre, with a flat zone between the bosses. This flat zone may comprise a diametrical strip. In this embodiment, the opening means may be located on the flat zone between the bosses.

The opening may be a score and opening ring or tab. Alternatively, the opening means may be a diaphragm, plug or cap which may be heat sealed over an aperture in the end panel . The end may include a further closure to cover the opening means or an aperture formed on opening the end. This closure is preferably of plastics material.

According to a second aspect of the invention, there is provided a container comprising a container body and at least one end fixed to the body and having a curled edge, said end being characterised as described above.

In a preferred embodiment, the container body s necked at the end of its sidewall to which the container end is fixed. By necking the container, savings in material costs are possible and stacking of containers is made easier. Furthermore, where the container is a three-piece can, this neck facilitates the seaming process.

According to a further aspect of the present invention, there is provided a method of manufacturing a container comprising a container body and at least one end having a curled edge, characterised by forming a container end having a curled edge depending from a substantially planar end panel and at least one raised boss on the end panel, engaging the boss or bosses on the locating chuck and feeding and centring the end on the container body.

Preferably the container comprises a cylindrical body and the method further comprises introducing a mandrel into the cylindrical body so that the mandrel abuts at least the end of the inner wall of the body to which the end is to be fixed, and aligning the locating chuck axially with the mandrel. The method may further comprise providing a centring release mechanism or similar device, typically on the chuck, to cooperate with the boss or bosses . Where the container body is necked, the mandrel abuts the inner side wall at the necked portion, thus facilitating a seaming operation using a conventional outer seaming roll acting radially against the side wall. The mandrel resists and offsets the radially inward force caused by the action of the seaming roll. According to a still further aspect of the present invention, there is provided an apparatus for assembling a container comprising a cylindrical body and an end having a curled edge, characterised in that the end has a curled edge depending from a substantially planar end panel and at least one raised boss on the end panel, and in that the apparatus comprises a mandrel for introducing into the cylindrical body so as to abut at least one end of the inner side wall, and a locating chuck to engage the boss or bosses to centre and feed the container end to the container body.

Preferred embodiments of the invention will now be described, by way of example only, with reference to the drawings, in which:

Figure 1 is a side section of a blank for forming a container end;

Figure 2 is a side section of the blank of Figure 1 after a first forming step;

Figure 3 is a side section of the blank of Figures 1 and 2 after a second forming step;

Figure 4 is a plan view of the blank of Figure 3;

Figure 5 is a plan view of a can end with easy opening feature;

Figure 6 is a side section of stacked can ends;

Figure 7 is a schematic side section of an apparatus for positioning an end on a can body; Figure 8 is a schematic partial side section of a prior art end;

Figure 9 is a schematic partial side section of an end according to the invention;

Figure 10 is a plan view of an end with a second embodiment of opening means; and

Figure 11 is plan view of an end with a third embodiment of opening means.

A metal can end 11 is formed from a blank of sheet metal as shown in figure 1. Initially, the edge of a circular blank is curled in conventional manner but without stamping a countersink in the end panel. A blank with downwardly curled edge is shown in figure 2. A further step or steps result in a boss 13 (figure 3) or bosses 13a, 13b positioned symmetrically about the centre of the blank (figure 4) . These bosses will be substantially level with the edge 16 of a can body 17 after assembly as described below.

A can end of the easy open type is shown in figure 5. In the figure, each boss 13a, 13b has a shape in plan view which is a segment sharing the same centre as the end itself. The chords of each segment define a rectilinear strip 15 between the bosses 13a, 13b which are positioned symmetrically about a diameter of the end. The opening means of figure 5 is provided on the rectilinear strip 15 and comprises a score 19 and a ring- pull tab 20 fixed by a rivet 21 to the end panel within the score 19 itself. This positioning of the ring-pull prevents any accidental opening of the can during handling or transport etc since the two bosses 13a, 13b protect the ring-pull positioned between them. Turning now to figures 10 and 11, in the embodiment of figure 10, the opening means 18a comprises a diaphragm 22 which is heat sealed or otherwise fixed over an aperture 23 in the strip 15. One end of the diaphragm 22 comprises a tab 25 for peeling the diaphragm off the end.

The embodiment of figure 11 includes a protective cover 28 which may be of plastics material. This cover fits between the two bosses and covers the opening device. This device can be that of figure 5, figure 10 or indeed some other system. The cover may take the form of a plug which enables the aperture 23 to be reclosed after partial emptying of the can contents. It may also be sealed initially at both ends to the edge of the can body so as to provide tamper evidence to the consumer at the time of purchase.

As figure 6 shows, the ends 11 are easily stacked on top of one another without any risk of catching on each other. The bosses also allow the ends to be mutually centred for presentation to the assembly station and the curled edges 12 separate the ends from each other, limiting contact between them.

The role of the bosses at the assembly station can be better understood from figure 7. That figure shows an assembly machine comprising an axially aligned mandrel 30 and chuck 32. The mandrel 30 is inserted within the can body 17 as far as upper edge 16 and contacts the inner side wall at the neck 14. The chuck 32 has a central recess with a complimentary shape to that of the bosses 13a, 13b so that the chuck and bosses engage in order to centre the end 12 relative to the can body.

Chuck 32 further includes an internal centring release mechanism 36 in the form of a tapered surface which co-operates with the bosses to allow perfect centring and feeding of the end to the can body, prior to seaming.

In operation, the mandrel 30 prevents radial movement of the can body and the end is held between the chuck 32 and the mandrel 30, while being centred by the chuck. A seaming roll 35 is thus able to perform the seaming operation in known manner and form a seam between the end and the can body. Typically a gasket 38 of elastomeric material within the curl of the end is used to improve the seal of the assembled can.

Figures 8 and 9 give a comparison of the prior art can end and the end of the present invention. From the figures it is clear that there is no countersink 40 in the end of the present invention, thus avoiding accumulation of product at the edge of the can.

As is noted above, the can body is necked 14 which not only facilitates seaming, but also axial movement of the mandrel 30 within the can body and stacking of the cans.

It will be appreciated that the invention has been described above by way of example only and that any boss configuration which allows good centring and feed at the time of seaming falls within the scope of the invention.

Claims

CLAIMS :

1. A container end (11) comprising an end panel having a curled edge (12), characterised in that: the curled edge (12) depends substantially from a substantially planar end panel; and the end panel further includes at least one raised boss (13), adapted to engage a locating chuck (32) .

2. An end according to claim 1, comprising two bosses (13a, 13b), one on either side of the centre of the end and a flat zone (15) between the bosses.

3. An end according to claim 1 or claim 2, further comprising opening means (18) fixed to the end panel.

4. An end according to claim 3, in which the opening means is fixed to the flat zone.

5. An end according to claim 3 or claim 4, in which the opening comprises a score (19) and a tab (20) , or a diaphragm (22) fixed to the end panel and covering an aperture (23) .

6. An end according to any one of claims 3 to 5, further comprising a closure (28) covering the opening means or aperture formed in the end panel on opening the end.

7. A container comprising a container body (17) and at least one end (11), characterised by an end according to any one of claims 1 to 6.

8. A container according to claim 7, in which the container body is necked (14) at the end of its side wall to which the container end (11) is fixed.

9. A method of manufacturing a container comprising a container body (17) and at least one end (11) having a curled edge (12) characterised by: forming a container end (11) having a curled edge (12) depending from a substantially planar end panel and at least one raised boss (13) on the end panel; engaging the boss or bosses on a locating chuck (32) ; and feeding and centring the end on the container body.

10. A method according to claim 9 in which the container comprises a cylindrical body, the method further comprising: introducing a mandrel (30) into the cylindrical body so that the mandrel (30) abuts at least that end of the inner side wall of the body to which the end is to be fixed; and aligning the locating chuck axially with the mandrel .

11. An apparatus for assembling a container comprising a cylindrical body (17) and an end (11) having a curled edge (12), characterised in that: the end (11 has a curled edge (12) depending from a substantially planar end panel and at least one raised boss (13) on the end panel; and in that the apparatus comprises: a mandrel (30) for introducing into the cylindrical body (17) so as to abut at least that end of the inner side wall to which the end (11) is to be fixed; and a locating chuck (32) to engage the boss (13) or bosses (13a, 13b) to centre and feed the container end to the container body.

12. A method according to claim 11, further comprising a centring release mechanism.