GB2031775A

GB2031775A - Metal containers

Info

Publication number: GB2031775A
Application number: GB7840039A
Authority: GB
Original assignee: Monfalconesi E Passero & C Srl
Current assignee: Monfalconesi E Passero & C Srl
Priority date: 1978-10-10
Filing date: 1978-10-10
Publication date: 1980-04-30
Also published as: GB2031775B

Abstract

A metal container E of cylindrical or frusto-conical shape includes a ring 5 integral with the container and arranged to hold in place a lid press-fitted into the ring. A method of producing the container E and the tools employed are also described. The containers are made from flat sheets by rolling them round and soldering the seams. The container block B as obtained is placed over a tool comprising expansion pieces 10 which move outwardly to provide internal pressure on container blank B' to form a flat inwardly bent flange at the top. The blank is then placed over another tool with the flat flange resting on an annular disc (14), Fig. 11 (not shown) and outwardly movable pieces press the flange on the die to form concavity G'. <IMAGE>

Description

SPECIFICATION Sheet metal containers This invention is concerned with sheet metal containers such as are used to contain paint, varnish, thinners, chemicals etc. Customarily such containers comprise a hollow metal shell of cylindrical or frusto-conical shape closed at its bottom end and having at its top end an annular, internally-projecting, flange serving to hold in place a lid, of known character, when the lid is applied to the container.

As far as we are aware a flange of this nature has, heretofore, always been constituted by a ring of metal separate from that of the shell and secured in place upon the shell, at the top end of the shell, by a soldering operation or by adhesive, the metal of the shell and that of the ring being rolled together.

One of the various objects of the present invention is to provide an improved sheet metal container. Another of the various objects of the present invention is to provide an improved method of making a sheet metal container.

The present invention provides a container made from sheet metal, the container comprising a hollow metal shell of cylindrical or frusto-conical shape, closed at its bottom end and having at its top end an annular flange integral with the shell and extending inwards and then downwards, the flange serving to hold in place a lid, of known character, when the lid is applied to the container.

Preferably, in a container as provided by the invention, the flapge comprises an inwardly-extending annular outer part, the outer edge of which is integral with the top end of the shell and the inner edge of which is integral with a down-turned annular inner part. The present invention also provides a method of making such a container wherein a metal shell of cylindrical or frusto-conical shape is subjected to internal pressure at a locality near one end of the shell thereby to expand the shell at said locality and cause the metal of the shell, at said end of the shell, to turn inwards towards the axis of the shell to constitute the flange, the flange being thereafter subjected to the action of shaping tools to cause the formation of the down-turned annular inner part and, if desired, of an annular gutter in the outer part.

The above and other of the various objects of the present invention, and the invention itself in its various aspects, will become more clear from the following description, to be read with reference to the accompanying drawings of a container illustrative of the invention, and of a method of making it, which method is also illustrative of the invention but in a different aspect; it will be realised that this illustrative container and illustrative method have been selected for discription by way of example and not of limitation of the invention.

In the accompanying drawings: Figure 1 shows, partly in radial section and partly in elevation, an upper part of a container made by a known method; Figure 2 shows a lid, of known character, which may be applied to the container of Fig.

1; Figure 3 shows the illustrative container, partly in radial section and partly in elevation; Figures 4 to 7 show consecutive steps in the making of a cylindrical shell as a preliminary in carrying out the illustrative method thus, Figure 8 shows an expanding tool used in operating upon the shell of Fig. 7; Figure 9 shows the tool of Fig. 8 in operation upon the shell of Fig. 7; Figure 10 is an enlarged view of part of Fig. 9; Figure 11 shows a set of shaping tools used in operating upon the shell of Fig. 9; Figure 12 shows the shell of Fig. 9 after operation thereon by the tools of Fig. 11; Figure 13 is an enlarged view of part of Fig. 12; Figure 14 shows applying a bottom to the shell of Fig. 12; and Figure 15 shows a final, optional, step in carrying out the illustrative method.

Referring now to Fig. 1, this shows an upper part of a container, D, made by a known method. In carrying out this known method a cylindrical shell B and a separate ring A of metal are secured together by a soldering operation or by adhesive, the metal of the shell B and that of the ring A being rolled together as indicated at 1. The ring A provides an annular, internally-projecting, flange F having an inwardly-extending outer part 2 and a down-turned annular inner part 3. The part 2 of the flange F presents, in its upper surface, an annular gutter G.

Fig. 2. shows a lid L, of known character, which may be applied to the container D of Fig. 1 to seal the opening bordered by the inner part 3 of the flange F in an airtight fashion. However, the roll at 1 may not be airtight, and contents may leak from the container D through this roll even if the lid L itself makes an airtight closure.

Fig. 3 shows, at E, the illustrative container.

As will be seen, the container E, looked at from above, presents all the features of the container D, and differs from the container D essentially in that it has an annular flange 5 integral with its shell B'. The flange 5 comprises an inwardly-extending annular outer part 7, the outer edge of which is integral with the top end of the shell B' and the inner edge of which is integral with a down-turned annular inner part 8. The outer part 7 of the flange 5 has a gutter G', while at 6 the shell B' is shown expanded somewhat. The shell B' is provided with a supporting rib 4.

At C is shown a sheet metal bottom which may be applied to the shell B' by any known method, but it is shown that the metal of the shell B and that of the bottom C are rolled together and secured by soldering.

Turning now to Figs. 4 to 7, these show consecutive steps in the making of the shell B' as a preliminary in carrying out the illustrative method. Thus Fig. 4 shows rectangular sheets of metal in a stack. Sheets from the stack are fed one by one to the rolls of Fig. 5 to shape them into cylinders with open seams as shown in Fig. 6. These cylinders are then soldered along the seams, to close them, as suggested in Fig. 7, to give shells like the shell B'.

Next, in carrying out the illustrative method, a shell B' obtained as in Figs. 4 to 7, is placed upon an expanding tool shown at 9 in Fig. 8. The tool 9 comprises an operating cylinder carrying many relatively movable expansion pieces 10. When the tool 9 is operated the shell B' is subjected to internal pressure at a locality near the top end of the shell thereby, as shown in Figs. 9 and 10, to expand the shell B' at said locality and cause the metal of the shell, at the top end of the shell, to turn inwards towards the axis of the shell B' and constitute the flange 5, see Fig.

10.

The tool 9 also includes a groove 11, and at the bottom end the shell B' is turned out, as shown at 12, when the tool 9 operates.

Next, in carrying out the illustrative method, the flange 5 is subjected to the operation of shaping tools shown in Figs. 11 and 12.

These tools include a machine frame 13, an annular die 14 having an annular projecting ridge 14', and a cylinder 15 carrying many relatively movable pressing pieces 16, each of which has a cavity to straddle the ridge 14'.

The shell B' is presented upside-down to the tools of Fig. 11, and when the tools operate the part 8 of the flange 5 is shaped between the ridge 14' and the pressing pieces 16 to form the gutter G' (as shown in Fig.

1 3), while the part 7 is turned (upwards in Fig. 12) to shape it as required.

Fig. 14 shows the bottom C' being applied to the shell B' while Fig. 15 shows a final, optional, step in carrying out the illustrative method, viz., providing studs 17 for anchoring a handle 18.

Claims

1. A metal container which is adapted to be closed by a lid pressed into a ring portion surrounding a mouth of the container, wherein the ring portion is formed by bending an end portion of a wall of the container inwardly of the container.

2. A metal container according to claim 1, wherein, in radial cross-section, the ring por tion includes a first portion which is disposed inwardly of the said wall substantially perpen- dicularly thereto and a second portion which is further bent inwardly of the container.

3. A metal container according to claim 2, wherein the said first portion is, when viewed from outside the container, concave, the con cavity forming an annular gutter surrounding the mouth of the container.

4. A metal container according to claim 3, wherein that portion of the said wall of the container which is adjacent to the said first portion swells outwardly of the container forming an annular widening of the container about the mouth thereof.

5. A method of making a container ac cording to claim 1 which includes the opera tion of bending an end portion of the said wall of the container inwardly of the con tainer.

6. A method according to claim 5, where in in the said operation the said wall of the container is also bent to form an annular widening of the container about the mouth thereof.

7. A method according to claim 5, where in in the said operation the said wall of the container adjacent to the ring portion is pressed into its shape.

8. A method according to claim 7, where in in the said operation an annular rib is formed on the exterior surface of the said wall of the container.

9. A moulding tool for use in making a container according to claim 2 by the method according to claim 5; which includes a plural ity of movable shaped pieces which are ex pandable outwardly of the tool to press the wall of a container placed over the tool, the shaped pieces being shaped to bend the said wall to form at least the said first portion of the ring portion.

10. A moulding tool according to claim 9, wherein the said shaped pieces are expanded as aforesaid by the movement of an expansion cylinder transmitted thereto.

11. A moulding tool for use in making a container according to claim 3, which in cludes an annular die shaped to form the said concave gutter and the said second portion of the ring portion, and a pressing head which is arranged to fit inside the container, the press ing head having a plurality of expanding sec tions arranged to cooperate with the said annular die to form the said concave gutter and second portion of the ring portion.

12. A metal container having a ring por tion, surrounding a mouth of the container, substantially as hereinbefore described with reference to Fig. 3 of the accompanying draw ings.

13. A method of making a metal container substantially as hereinbefore described with reference to Figs. 4 to 13, inclusive, of the accompanying drawings.

14. A tool for use in making metal containers having its parts constructed, arranged and adapted to operate substantially as hereinbefore described with reference to Figs. 8 and 9 of the accompanying drawings.

15. A tool for use in making metal containers having its parts constructed, arranged and adapted to operate substantially as hereinbefore described with reference to Figs. 11 and 12 of the accompanying drawings.