GB2227223A

GB2227223A - Securing ends to metal containers

Info

Publication number: GB2227223A
Application number: GB8928535A
Authority: GB
Inventors: Gunter Hexel
Original assignee: Schmalback Lubeca AG
Current assignee: Ardagh Metal Beverage Germany GmbH
Priority date: 1988-12-16
Filing date: 1989-12-18
Publication date: 1990-07-25
Also published as: NL8903048A; NO894969D0; NO894969L; DK635989D0; DE3842452A1; DE3842452C2; GB8928535D0; DK635989A; SE8904191D0; SE8904191L

Description

1 1 1 M&C FOLIO: 230P60211 WANGDOC: 0369o A container The invention

relates to a container, particularly a container in the form of a pail. canister or drum formed from sheet metal and having a press-in cover. The container and/or the cover can also be formed from a sheet-metal/plastics composite.

Containers of this type are generally large barrels formed from relatively strong sheet-metal materials. with or without mouldings. in particular of the body wall, serving for reinforcement.

An object of the invention is to improve the strength of barrels of this type so as to be able to withstand rough handling during transport or stacking or the like.

The invention provides a container as claimed in Claim 1.

By means of the invention the rim area of the container. in which the surfaces of the body and the cover contact one another. is constructed in such a way as to form a tyre-like reinforcement of the container. what is essential in this connection is that the cylindrical rim area of the body and/or of the cover is reinforced in ( - ' 1 2 the manner of a tyre by at least singLe folding of the rim area. This reinforcement is substantially increased by the respective outermost sheet-metal layer in this rim area and the two sheet-metal layers of the body and the cover lying directly adjacent one another being welded to each other in a single seam located at an axial distance from the outer rim of the container.

In particular. the cylindrical rim area of the body is preferably bent over from the outside to the inside at least once, in order thereby to ensure the tyre-like reinforcement, while the cylindrical rim of the cover can consist of a single sheet-metal layer.

In a preferred embodiment, the cylindrical rim area of the cover is nested between two sheet-metal layers of the rim area of the body and is welded to these two sheet-metal layers.

Welding is preferably carried out without contact with the sheet-metal layers with the aid of high-energy radiation. For this purpose the known techniques of electron-beam welding, laser-beam welding or the like can be applied.

By virtue of the invention an optimum compromise between the outlay in sheet-metal material and the reinforcement 1 A 3 effect can be achieved for each individual case of application. In most cases of application. it has been found that a particularly successful embodiment is where the press-in cover is supported on one peripheral corrugation of the container body and the single cylindrical rim area of the cover is nested between the outer sheet-metal layer of the body andthe-rim area of the body folded from the outside to the inside. The rim area thus formed is then securely welded radially from the outside to the inside through at least one sheet-metal layer of the body. 1n this way an excellent tyre-like reinforcement of the container is achieved with a moderate con5i;mption of material. The free edge of the cover is thel --mbedded between the sheet-netal layers of the body while the free edge of the folded sheet-metal rim of the body lies close to the bottom of the cover on the inside of the reinforced rim. The tree edges are thus enclosed and therefore largely prevented from being touched or causing damage. In any case the tree edge of one part of the container can also be bent in the direction of the adjacent sheet-metal Layer, in order thereby to form further protection against contact or causing damage.

Embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, wherein; 4 Figs. 1 to 6 are each similar illustrations in vertical cross-section of a selected portion of one embodiment of a container according to the invention.

The illustrated containers according to the invention, which consist of sheet metal. are barrels in the form of pails, canisters or drums, for example with a capacity of between 10 and 30 litres. Containers of this type are frequently produced from relatively thick tin plate which is for example 0.20 to 0.30 mm in thickness.

ln the case of most containers of this type. the body 2 (Fig. 1) is provided with a peripheral corrugation 3 located at an axial distance from the upper edge 9 of the container. The corrugation 3 projects radially inwardly and can also comprise a plurality of discrete corrugation portions distributed in the peripheral direction rather than a single continuous corrugation. This peripheral corrugation is used to support the press-in cover 6 and therefore also for fixing the position of the said cover relative to the body.

In some cases, a peripheral corrugation of this type can be dispensed with. as shown in Fig. 2. In this case the press-in cover 16 rests with its bent or folded rim 17. 19 on the upper rim of the body 12. so that in this way i the cover is secured in position relative to the body.

In all the embodiments the rim of the container 1 (Fig. 1) is reinforced in the manner of a tyre.

In the case of the embodiment according to Fig. 1, the cylindrical rim area of the body is folded from the outside to the inside (sheet-metal layers 2a and 4). In this case the area 5 partly bounded by the free edge of the rim is folded inwards a second time. so that the free edge comes to lie inside the reinforced container rim. The press-in cover 6 is nested with its cylindrical rim area 7 located between the sheet-metal layers 2a and 5 of the body rim.

In addition to this reinforcement, the rim area of the container is reinforced by a welding seam which is situated at an axial distance a from the final upper rim 9 of the container. The welding seam 8 is formed by contact-free welding. in particular with the aid of high-energy radiation such as electron beams or laser beams. Welding takes place in the radial direction. It can, provided there is sufficient space therefor, take place radially from the inside to the outside. It is preferable. however. for the welding to take place in the direction of the arrow R from the outside to the C 6 inside of the container.

In both cases. the welding is carr ied out in such a way that the sheetmetal layer facing the welding device (i.e. either the sheet-metal layer 4 when welding from the inside to the outside or the sheet-metal layer 2a when welding from the outside to the inside) and the sheet-metal layers of the body 2 and cover 6 lying directly adjacent one another are jointly welded to one another.

In the embodiment according to rig. 1, therefore, when welding from the outside to the inside. only the sheet-metal layers 2a and 7 can. if necessary, be welded to each other. since the sheet-metal layer 2a forms the outer sheet-metal layer of the container rim and in addition, this same sheet-metal layer lies directly adjacent the sheet-metal layer 7 of the cover 6.

Preferably, however, the welding takes place radially from the outside to the inside as shown in Fig. 1. the nested sheet-metal layer 7 of the cover 6 being welded to both of the two sheet-metal layers 2a and 5 in direct contact therewith.

On account of the relatively thick metal sheets of from 0.20 to 0.30 mm and the bending or folding of the body 7 rim in conjunction with the welding of at least two or three sheet- metal layers (depending upon the design), an extremely rigid tyre-like rim structure of the container 1 is obtained. In the case of the embodiment according to Fig. 2 which can be preferred in some types of application. the body 12 of the container 10 has no peripheral corrugation. The cylindrical rims of both the body and the cover 16 are each bent outwards, the rim of the cover 16 being folded around and covering the reinforced rim of the body 12, so that one container rim is again produced from four sheet-metal layers. When welding from the inside to the outside, at least the sheet-metal layer 17 of the cover would be welded to the sheet-metal layer 12 of the body. in the case of the preferred welding from the outside to the inside. the outer sheet-metal layer 19, which belongs to the cover 160 is welded to the sheet-metal layer 14 of the body in contact therewith and preferably also to the upper area of the body itself, so that once again two, and preferably three, sheet-metal layers are securely connected to one another at a distance from the upper container rim.

While both edges of the sheet-metal layers are protectively arranged within the container rim in the case of the embodiment according to Fig. 1. the edges of the sheet-metal layers are exposed in the ease of the U.

8 embodiment according to Fig. 2. It is therefore advisable to bend the tree edge 11 of the outer sheet-metal layer 19 towards the container body, so as to cover the free edge of the sheet-metal layer 14 and thereby to prevent obstructions or damage by the sheet-metal edge 11.

A further, preferred embodiment is shown in Fig. 3. in the case of the container 20 shown in this Figure the cylindrical rim 27 of the cover 26 is without reinforcement. The cover 26 is supported on the corrugation 23 and the cylindrical rim of the cover is nested between the cylindrical rim of the body 22 and a rim fold 24, so that the free edge of the sheetmetal layer 27 is enclosed within the folds of the container rim. All three sheet-metal layers of the container rim are welded together by the welding seam 28. Here too the free edge 11 of the sheet- metal layer 24 can be easily bent in the direction of the cylindrical rim of the cover 26, in order to further protect the free edges from contact.

It is evident that a container rim which is highly reinforced in the manner of a tyre is obtained in the case of the embodiment according to Fig. 3 with a reduced use of material. In contrast to the embodiment according to Fig. 1. however, the drawback of an exposed j _ 11 9 tree edge 11 must be reckoned with.

The invention can be modified in numerous ways, Fig. 4 to 6 showing some examples of those modifications.

Fig. 2 differs from Fig. 4 in that the cylindrical rim of the body 32 of the container 30 of Fig. 4 remains unreinforced while the cylindrical rim 37 of the cover 36 in the region above the peripheral corrugation 33 is folded once over the body rim and additionally once over itself, so that two sheet-metal layers 39a. 39b of the cover lie on the outside of the body rim. in the case of welding from the outside to the inside these two layers are welded to the body rim by the welding seam 38. In the case of the embodiment according to Fig. 4 the welding seam also extends to the inner sheet-metal layer 37 of the cover 36.

The embodiment according to Fig. 5 differs from the above embodiments in that the cover 46 is inserted as far as the corrugation 43 of the body 2. without the cylindrical ends of the body and the cover being connected to each other mechanically. The two cylindrical rims are in fact folded over once each. namely in opposite directions. In the case of welding carried out from the outside to the inside, the welding seam extends to the body rim includtng the folded-over sheet-metal layer 44 and also to the sheet-metal layer 47a of the cover 46 touching the body rim. The sheet-metal layer 47b is not embraced by the welding seam 48. In this embodiment both sheet-metal edges are free.

The embodiment according to Fig. 6 is a further development of the embodiment according to Fig. 3. it differs from the latter in that both the cylindricaL rim 57a of the cover 56 and the rim 54 of the body 52 are bent over from the outside to the inside, so that in this case the rim of the container 50 comprises tour sheet-metal layers as opposed to the three sheet-metal layers of Fig. 3. In addition, Fig. 6 clearly shows that only two layers need be joined to each other by the welding seam 58. In the case of welding from the outside to the inside. they are the outer sheet-metal layer of the body 52 and the sheet-metal layer 57a of the cover which are in contact with each other.

In all the embodiments the welding seam is formed only after producing the mechanical deformation of the body rim and the cover rim.

Figs. 2a. 3a and Sa show further possibilities for protecting the free edges. According to these i!'igures, the outer edge (Fig. 2a) or even each tree edge can have Z A 11 an inward rolling 11a (Figs. 2a, 5a). The tree edge or each free edge lia can also be bent so as to extend into a sheet-metal corrugation. for example into the present peripheral corrugation 43a (Fig. 5a) or into a corrugation 26b formed therefor (Fig. 3a). The tree edge can also be provided with a protective coating.

A "cylindrical rim area,' can be understood as being both a circular cylindrical shape and also a shape deviating therefrom. In this connection, llessentially cylindrical,, means that the rim area. deviating from a strict cylindrical shape. can also be made slightly tapered. What has been stated in the embodiments concerning the cover can also correspondingly apply to the base of the container.

C.

12

Claims

C L A I M S

1. A container formed from sheet metal and/or a sheet-metal/plastics composite, having a press-in cover andlor a press-in base, characterized in that the essentially cylindrical rim area of the body and/or the cover andlor the base is reinforced by at Least a single folding of the rim, and at least the respective radially outer or inner sheet-metal layer of the rim area of the container and the two directly adjoining sheet-metal layers of the body and the cover or base are welded together at an axial distance from the container outer rim.

2. A container according to claim 1. characterized in that the cylindrical rim area of the body is folded over at least once from the outside to the inside and is provided with a peripheral corrugation projecting radially inwards for axially locating the press-in cover or base, and at least two sheet-metal layers of the reinforced body rim are welded to at least one sheet-metal layer of the press-in cover or base.

3. A container according to claim 2. characterized in that the cylindrical rim of the press-in cover or base is nested between two sheet- metal layers of the reinforced rim of the body and is welded to the said two 1; 13 sheet-metal layers.

4. A container according to any one of Claims 1 to 3, characterized in that the sheet-metal layers are welded together in the radial direction by means of a contactfree welding utilizing of high-energy radiation.

5. A container according to Claim 4, characterised in that the welding takes place from the outside to the inside.

6. A container according to any one of Claims 1 to 5. characterized in that the respective free edge of a folded-over rim area is bent or rolled in the direction of the adjacent sheet-metal layer

7. A Container according to any one of Claims 1 to 5. characterized in that the respective free edge (11) of a folded-over rim area is shaped to extend into a corresponding corrugation provided in the cover or body.

8. A container substantially as hereinbefore described with reference to any one of the embodiments shown in the accompanying drawings.

Pubunhed 1990 atThe Patent Office. StIlite HOuse.66171 Iligh Holborn, London WC1R4TP.P copies maybe obed from The Patent Mce.