GB2157256A - Sheet metal container with integral rim - Google Patents

Abstract

A sheet metal cylindrical container has its top edge folded outwardly to form an annular inverted U-section lip, and this U-section lip is further shaped and deformed to provide a multi-fold 931-934 reinforcing flanged rim located externally of the body member but materially integral therewith. Preferably the top edge is initially formed into a roll-edge 90 which, after deformation of the lip, preferably lies against the cylindrical wall. The flanged rim can conveniently accept a lever off closure lid, and also provide a shoulder to support a lid levering tool. The external rim facilitates liquid pouring. The container's bottom 50 can be provided and fitted in a known way. The ends 94, of a carrying handle 94 can be clamped in the folds of the rim. <IMAGE>

Description

SPECIFICATION Method of manufacturing hollow sheet metal containers The present invention relates to a method of manufacturing hollow containers which have sheet metal walls.

Previous hollow containers having sheet metal walls included a peripheral ring at the open mouth of the container serving as a reinforcement and facilitating the fitting of the container's lid, and also removal of the lid by a levering action. This ring was manufactured separately from the container's main body and subsequently securely fitted to the open mouth of the body: this is wasteful in material usage and there is the additional disadvantage of increasing the manufacturing time of a container.

It is an object of the present invention to provide lower consumption of raw materials during the processes of manufacture of containers made of plate or sheet metal, and therefore a lower cost for this item.

It has as another object, the reduction in the manufacturing costs, not only because of the decrease in the cost of raw materials used, but also because of the decrease of the number of operations necessary for manufacturing the container.

Another object of this invention lies in the reduction of financial investment costs, in comparison to the usual costs, which the invention makes possible.

According to the present invention there is provided a method of manufacturing a hollow sheet metal container comprising the steps of providing an annular sheet metal body member, and folding and shaping the top part of said body member to form an annular reinforcing flanged rim located externally and radially outwardly of the remaining portion of said body member but materially integral with said remaining portion.

The present invention is also a sheet metal container manufactured in accordance with the above method.

Embodiments of the present invention will now be described by way of example with reference to the accompany drawings in which: Figures 1 and 2 as well as the details which appear in Figures 1-A; 2-A and 2-B illustrate stages of the manufacture and details of the joint of a conventional, metal sheet, cylindrical container with a base made with a detachable sealing ring which has been fitted on the inner side of the container opening.

Figures 3, 4, 5, 6, 7, 8 and the details of figure 8-A show the principle stages of a known process of manufacture of a conventional stackable, truncated cone shaped container and the detail of this container.

Figure 9 shows two conventional truncated cone shaped containers which have been produced according to the stages of manufacture shown in figures 3 to 8 and located in a stacked condition.

Figures 10, 11, 12, 13, 14, 15 and 16 and the figures in details 10A; 10-11B; 14A; 15A; 16A; 16B; show the main stages of manufacture of stackable, truncated cone shaped containers, with flexible handle attachments, according to the present invention and several structural details of the said containers, according to an advantageous method of application or execution of the present invention.

Figures 17 and 18 show diagrammatically the principle stages of manufacture of stackable, truncated cone shaped containers according to a conventional method, and according to the method of the present invention respectively.

Finally Figures 19 and 20 show respectively two containers according to the present invention one being cylindrical, and the other a stackable truncated cone shaped container.

Referring to Figs. 1 to 9, a great many of the previous hollow sheet metal containers were produced by means of the coupling of a hollow body 10 made out of sheet metal welded using for example an electrical generator, which container in the initial manufacturing stages at least is cylindrical, (Fig. 1 & 3) with a sheet metal detachable ring made independently from the hollow body 10 Figs. 1 - 7) in such a way that, at a certain stage of the manufacturing process the ring and body are coupled (Figs. 1-A; 2-A)by folding the protruding flanges of both elements 11 - 21 in order to form a peripheral coupling edge roll 30 between both elements.The procedure, therefore, is similar to that of the coupling of the base 40 (Figs. 2:msB) with respect to the metal sheet side walls of the body 10, using other lowermost peripheral flanges 12, similar to those 11 which are folded by the peripheral part of the base in order to make the peripheral edge roll 50 of the base 40.

The said detachable ring 20 generally has folded flange portions on its inside 22, 23, 24 and 25 which enable securement of the lid (not illustrated) which fits into the peripheral space made by the said folded portions, so enabling the air tight closure of the container on its upper part. It should be noticed that, once that coupling between both elements 10 and 20 is achieved the portion 22 which remains at a slight angle (Fig. 2-A) constitutes, together with the edge roll 30, the elements which allow the container to be easily opened through the right amount of pressure being placed on a point on the lid while it is levered open by an instrument which engages the same peripheral edge roll 30.With regard to the manufacture of truncated cone shaped containers which, also must be easily stacked, the assembly and coupling of this detachable ring 20 places other problems as, being joined to the container by its inside, it makes the widening of the original hollow body necessary to enable stacking of containers or to enable other containers to pass through its upper opening. This can be seen in figures 3, 4, 5, 6, 7 in which the possible principal stages of manufacture of cans or containers of this sort which need to be widened are seen (fig. 4) 14 & 13 joined to the formation of the cones body 10,1; the assembly of the base 40 (Fig. 5); the formation of the edge roll of the base 50 (fig. 6) with the following latter tipping of the container so as to arrive in the position depicted in Fig. 7 in which the detachable sealing ring is assembled and fixed to the container 20.Depending on the type of container described the adaption and assembly of the lugs 60, is still to be done, and the peripheral stop rim 70 still to be made; also the flexible handle 80 is still to be assembled in order to arrive at the type of stackable container depicted in Fig. 8 and detailed in 8-A. Apart from the operations which have shown to be necessary it will be understood, especially from Fig. 9, that when two containers like these shown in Fig. 8 are stacked, there are vertical heights or spaces 'H' which determine the separation between two axially successive containers. The said separation depends, as can be seen, from height 'H' and on the space reserved for the assembly of the lugs 60 for the flexible handle 80.

It becomes evident that the lesser the vertical distance 'H' the greater the number of containers which in equal coditions, of sizes and surfaces, can be stored with a certain type of container.

Now once these preliminary explanations about the features and difficulties resulting from the usual methods of container manufacture have been given, it will be possible to more readily appreciate a practical example of the improvements of the present invention applied to the construction of stackable, truncated cone shaped, metal sheet containers, which also have been fitted with a special handle making the application and fixture of the conventional lugs of the conventional handle unnecessary.

As has been appreciated, the fact that we refer to this hypothetical process of manufacture, which is really much more complex, does not presuppose that these same improvements cannot be applied to other simpler cases like the manufacture of cylindrical containers, not for stacking, fitted or not fitted with the sort of flexible handle which is fastened on during, and as a result of, the formation of the upper, outer peripheric sealing rim formed from the actual metal walls of the original hollow cylindrical body and welded by means of an electrical generator.

Referring now to figures 10 to 16, the present improvements consist essentially in the elimination of the conventional detachable metallic ring 20 which is made separately from the main body 10.

Instead, only the actual sheet metal of the peripheral wall 10 of the container is used, and with certain outer folding operations is turned into a 'pocket' 92 (fig. 12A); the making of this 'pocket' will be followed by the external peripheral shaping of this upper folded zone 92 (Fig. 14A -15A) until it becomes a peripheral rim somewhat similar to that of the eliminated detachable ring 20, but the rolled metal shape remains a completely integral part of the metal sheet wall 10 of the container.

The said upper rolled steel shape 93 (similar to the eliminated ring 20) therefore remains as an integral part of the body 10 of the container, and is situated on the outer peripheral part of the container due to the effect of the external folding 92 and of the (also external) shapings executed in the aforementioned operations; therefore, apart from eliminating the costs of manufacture of a detachable ring 20, as well as the cost of the subsequent fitting of the said detachable ring to the main body of the container 10, the said upper rolled metal peripheral shape 93 integrated to and forming an external part of the walls 10 allows pourable contents which are more or less viscous - of the container, to be poured out more easily which would not occur in the case of a conventional container fitted with a detachable ring 20 fixed to the inside part of the walls of the container 10 (as will be seen from Fig. 8a).

To ease the work of folding the 'pocket' 92 it will be convenient to form - Figs. 10 - 10A - an inital upper peripheral edge roll 90 and an upper cylin dricai zone 91 with which the external folding of the 'pocket' 92 is achieved, which is important (Fig.

11) when dealing with the manufacture of truncated, cone shaped containers.

In this last hypothesis, the cylindrical container 10 of Fig. 10 is expanded, equipped with a conventional bottom 40, joined to the walls 10 by means of a lower edge roll 41 (Fig. 10B - 11B) so arriving at a structure like the one shown in the Fig. 11 11A where an upper peripheral edge roll 90; a cylindrical zone 91 (with which a 'pocket' 92 is made) and then, by meansof the effect of expansion or deformation shown by the two opposing arrows of Fig. 11 a lower truncated cone shaped zone 96 has been made, the slant (convergence angle) of which is shown with the angle If a container with a special handle is required, then at the moment the 'pocket' 92 is made, and taking advantage of its existence (Fig. 13 - 13A) one can insert into the 'pocket' and on opposite sides, the two ends 94 of a resistant, but at the same time articulated, band or strip 94, for example by means of folds on each side 94 made at 90 (Figs. 14 - 15) which form a salient edge at 45 on each side of the two opposite points of connection of the band 94.

In order to ease the catch of the said ends 94 it is convenient that they should both be fitted with retaining means, for example with a lance head 94 (Fig. 13A) which, once inserted in the hollow of the 'pocket' 92, may not be easily extracted from the inside of the pocket, the shaping of the outer peripheric rim 93 should be carried out as shown in Figs. 14, 15, 14A and 15A.

Finally, in order to make the container stackable, the depth should be reduced which, in this case, consists in slightly expanding the lower zone 95 of the container in a progressive way so as to reduce its cone shape 'to a lower value" shown in Figures 16, 16A, 16B, i. e. provides a greater angle of convergence. At the same time the outer stop edge proturbance 98 is made, and which will be used to limit the entrance of one container into another similar one when axial stacking takes place.With the previous description the steps which must be carried out to obtain a truncated cone shaped container which appears in Fig. 16, and which is fitted with an external and integrated peripheral rim 93, which can carry out the same functions as the conventional rim 20 which has been eliminated and which therefore allows perfect fitting and closure of the container's lid (which is not drawn so as not to complicate the diagrams unnecesarily). It may be convenient, at the same time as the edge roll 98 is made, to slightly widen the walls of the container in the zone 99 (Fig. 16A) so as to aid, on the one hand, the retention of the edge roll integral with the outer peripheral rim 93 and on the other the flexible adaptation of the edges of the lid against the ridge 99 ensuring in this way the air tight and firm closure of the said top.

For better understanding of these improvements there is now illustrated what a conventional manufacture line of hollow, truncated cone shaped, stackable, metal sheet containers consists of and the differences between the previous line and that required for carrying out the present invention. In particular, the reduction in manufacturing stages achieved by the present invention will be shown.

Figs. 17 and 18 show two diagrams, the aim of which is to communicate in a graphical and direct way the elimination and substitution of certain stages of manufacture and the possibility of using much simpler mechanical methods for the construction of hollow sheet metal containers, and in this exemplary case, of truncated cone shaped hollow containers fitted with handles. The line of conventional manufacture would cover, according to Figure 17.

a) The production of a hollow cylinder welded at stage 100.

b) The placing of a container in a vertical position in stage 101.

c) The shaping into frusto-conical form of the cylinder with the expansion stage 102.

dl The rimming and construction of edge rims at stage 103.

e) tipping at stage 104.

f) Rimming and the reduction of the depth by expansion in stage 105.

g) Fitting the bottom by means of a closing mechanism in stage 106.

h) Another tipping step at stage 107.

i) Assembly of the detachable ring on the upper opening at the closing stage 108.

j) Welding of the side lugs of the handle at stage 109.

k) Assembly of the handle with a handle manufacturing and fitting machine at stage 110.

I) Varnishing at stage 111.

m) Oven drying at stage 112.

n) Stacking at stage 113.

According to the present patent the line of manufacture and operations would be very different, as depicted in Fig. 18: a) Stage 200 is equivalent to 100 of Fig. 17.

b) Stage 201 which consists in the rimming and making of the initial rim 90.

c) Stage 202, which would be fitting of the bottom. lt should be noticed that the fact that the bottom is fitted during the initial stages of the process is a significant feature of the improved process of the present invention, as this reduces the number of operations necessary and allows the use of simpler and cheaper machinery.

d) Stage 203: positioning of the container.

e) Stage 204: making the container into a frusto-conical shape.

f) Stage 205: making the 'pocket' 92 and assembly of the handle 94.

g) Stage 206: manufacture of the integrated external ring 93.

h) Stage 207: reduction of the depth at 95 and manufacture of an edge roll (proturbance) 98 and if necessary the retentive expansion 99.

i) Stages 208, 209, 210. These are equivalent to the finishing steps shown in 111 - 112 and 113 of the conventional process of Fig. 17.

From the aforementioned description it will be appreciated that the number of stages necessary, due to the present improvements, are far less than those necessary in an automatic, conventional manufacturing line process of manufacture. Apart from this it is also the case that this improved process allows the use of simpler and cheaper methods; above all in the group of operations shown in Fig. 18 with the letter "A". The said group A of operations can be carried out with an eccentric press, specially adapted in the form of a 'transfer' which is very effective and cheap in comparison with the methods normally used in conventional automatic lines of container manufacture.

According to these improvements, hollow, metal sheet containers are made which have a peripheral rib 93, the proportion of which is expressly exaggerated in figures 19 and 20, and which is made Fig. 19. - by folding outwardly the upper zone of the side wall 10 of metal sheet of the said container, shaping an upper peripheral fold facing outwards and downwards, and is what we have called a 'pocket' 92, and then the said upper peripheral fold will be pressed and shaped in order to make it into a hollow peripheral reinforcement and support rib 93 made up of, at least, three folded sections 93 932 933 preferably slanting, and arranged around the remainder of the unitary side wall 10 of the container; in this way the said hollow rim is placed around the upper peripheral curved rim 934 of the container where the conventional lid will be fitted.

In Fig. 20, the same three folded sections 93" 932, 933 appear and are placed externally around the curved peripheral rim 934. Also, featured in this type of truncated cone shaped container are the peripheral stop rim (proturbance) 98; the truncated cone shaped walEs 97; the depth reduction zone 95; the bottom 40 and the peripheral rim or lower edge roll 50, as well as the expanded zone 99 which is used to improve the fitting of the inner ridge of the lid (Not shown in the diagrams) to the hollow container, as well as to improve the fit of the initial edge roll 90 for the making of the 'pocket' begun in 92 and ultimately the production of external integrated rim 93.

In these diagrams one can also see the flexible integrated handle 94 with its articulated side sections 942.

The above method of manufacturing containers according to the present invention provides: a) A lower consumption of raw materials, in this case of metal sheet, compared to other similar arrangements.

b) The lower cost of personnel and manufacturing time due to the elimination of the independent manufacture of the container's sealing ring, and its subsequent assembly and joining to the wall of the container.

c) The lower cost of financing the production line, as, not only are the steps or stages of the production process reduced, but also a much cheaper means of production than the usual highly mechanised mass production lines can be used.

d) A lower cost of manufacture, because this invention envisages the manufacture of containers with flexible handles which form an integral part of the container, so dispensing with the conventional lugs of the ordinary rigid handles which conventional containers have.

e) A lower cost of manufacture as the assembly and joining of the bottom of the container is anticipated in such a way as to avoid unnecessary tipping operations so lessening in this way the stages or manufacture.

g) The inherent advantages of the container, which can be produced in accordance with this invention are as important as the aforementioned advantages derived from the lower cost of containers equipped with peripheral closing devices, which are totally equivalent to the best containers equipped with detachable (hence, added on) sealing rings.

The inherent advantages are basically of four types: A) By manufacturing the peripheral closing rim on the outer part of the container's opening, one avoids retention of the container's contents when poured out. This is very important for viscous liquids.

B) In the manufacture of hollow, stackable, truncated cone shaped containers, the usable space or height is reduced to a minimum and is lost in hiding the internal peripheral ring, and in the assembly of lugs used for the articulated fastening on either side of the conventional handle, therefore greater advantage can be taken of the storing capacity of the said stackable containers, in comparison to other similar arrangements.

C) With the peripheral closing rim integrated into the container's walls, one also reduces the number of operations necessary, and in particular, certain tipping operations and others, like the unnecessary widening of the container below the sealing ring.

D) The possibility of obtaining containers equipped with flexible handles, the ends of which are attached to the side walls of the container. This new possibility and feature is specially interesting in the case of containers carrying heavy loads of materials, where the fact that the handle can be flexible and adaptable helps the user to manage and transport the container comfortably, apart from the fact that the specific pressure on the part of the hand holding the handle is much less, due to the increased width of the element making up the handle.

Although Figs. 10 to 16 show the stages of manufacturing a stackable truncated cone container it will be understood that the inventive method can be used to make any form of annular container, e.g. cylindrical, of less complicated design (possibly without handles) and not necessarily stackable.

Claims (1)

1. A method of manufacturing a hollow sheet metal container comprising the steps of providing an annular sheet metal body member, and folding and shaping the top part of said body member to form an annular reinforcing flanged rim located externally and radially outwardly of the remaining portion of said body member but materially integral with said remaining portion.

2. The method according to claim 1, wherein during the formation of the reinforcing flanged rim the top part of the side sheet metal wall of the body member is bent outwards and downwards, and then an upper peripheral fold is pressed and shaped so as to form with it a peripheral hollow rib, a compound reinforcement and support made of at least three folded sections being arranged around the rest of the unified side wall of the body member, and placed around the upper peripheral rim of the body member where a lid of the container is to be fitted, a corner of one of said folded sections serving as a means of support and a place for levering off a lid fitted to the container.

3. The method according to claims 1 and 2, wherein on a peripheral upper and outer zone, with the same sheet metal which makes up its peripheral side wall, a peripheral resistant rim is shaped, composed of at least three folded sheet sections, in such a way that the free lower end of the outer section of the said rim rest on the outer face of the outer wall of the body member, whilst the other free end of the most internal section of the said rim is linked integrally with the outer upper peripheral lip of the body member where a lid will be fitted so that the folded rim which forms a peripheral hollow enclosure, and which encircles the upper lip where the lid is to be fitted, constitutes a reinforcement for the container at the height of the upper lip of the body member.

4. The method according to any of the preceding claims wherein the flanged rim comprises, at least, three folded rim sections, and initially the upper peripheral end of the sheet metal body member is formed with an annular reinforcement edge roll which ultimately makes up the free, lowe end of the outer rim section of the flanged rim.

5. The method according to claim 4 wherein said reinforcement edge roll comprises the free lower end of the outer section of a hollow peripheral enclosure defining the flanged rim, which edge roll during the pressing and rim shaping operation is caused to rest on the outer surface of the peripheral side sheet metal wall of the body member.

6. The method according to any of the previous claims, wherein the flanged rim comprises a hollow outer peripheral enclosure constructed around the outer peripheral lip of the body member for the lid, and there is supported inside the enclosure in opposite relationship, two ends of a flexible bandlike material, which when protruding out of the enclosure, constitute a flexible handle for the container; the two ends of the flexible band being inserted in an upper, outer peripheral fold of the sheet metal body member before proceeding to shape and form the said fold to make it into said external integrated rim.

7. The method according to any of the previous claims 1 - 5 wherein the flanged rim comprises a hollow annular enclosure, said hollow enclosure being adapted for the fastening of two opposite ends, in the form of a handle, of an auxiliary support and transport medium of the container, and wherein the fastening operation of either end are carried out by initially inserting each of these ends in opposite outer zones inside the interior of said hollow enclosure then proceeding to carry out the stages of pressing and shaping of the said hollow enclosure, to finally hold the said ends once the aforementioned, peripheral flanged rim has been shaped and formed.

8. The method according to claim 7 wherein the said ends of the auxiliary support and transport medium are partially articulated along one or more places along its length, so that a flexible band arrangement is provided having articulation ruts or similar means.

9. The method according to claim 8 wherein each of the two ends of the auxiliary means of support and transport of each container is provided with retention means suitable for acting as a stop means precluding extraction of the band from the inside of an initial outer peripheral fold before the shaping and pressing of this fold to make up the flanged rim in such a way that once these shaping operations of the said upper peripheral rim have been executed the said ends, initially held in their correct place, become securely fastened in the inside of the flanged rim in a clamped condition.

10. The method according to claim 9, wherein the retention means of the band ends is provided by bending back the ends in a hook like manner.

11. The method according to any of the previous claims, wherein an annular protuberance is from the sheet metal of the body member during a subsequent shaping operation which protuberance acts as a stop element for the axial stacking of each container in relation to a following container, said annular protuberance being located towards the top of the body member to maximise the number of containers stacked for a given height.

12. The method according to any of the previous claims 1 to 11 wherein when making hollow, truncated cone shaped, stackable containers the first operation is carried out by the expansion of the peripheral wall of the body member, with the base of the container already fitted and rimmed, giving the side walls a more conical shape than the ultimate container shape, and providing on the upper part of the body member an upper cylindrical strip inside of which all the aforementioned forming operations of the reinforcing flanged rim will be carried out, also, if applicable, the operation necessary for fitting two opposite ends of the flexible handle inside the flanged rim will also be effected thereupon proceeding to the final operations consisting in diminishing the increased conical shape by expanding the area near the bottom to achieve a diameter slightly greater than that of the base's peripheral joining rim,and progressively expanding the rest of the wall, finally arriving at the upper area where the reinforcing flanged rim has already been finished integral with the side walls, proceeding, during this stage of the operations with the formation of another peripheral rim or protuberance near to, and under, the upper flanged rim to act as an axial stop location of one container stacked inside another when similar containers are stacked.

13. The method according to any of the previous claims, in which there is provided a small peripheral expansion of the body member below the flanged rim which coincides with the area of contact of the inner end of an outer slanting rim or section of the said flanged rim, to facilitate in this way, by means of the said expansion, the retention of the container lids peripheral rim one it has been fitted to the said flanged rim.

14. The method according to any of the previous claims in which after executing welding of the side walls of the body member and the rimming of the body member as well as forming an initial upper peripheral edge roll, the container being of truncated cone form,including fitting a bottom to the body member then moving the body member to a transfer machine consisting of press means with several working positions by means of which several initial stages of expansion, are carried out then utilising this transfer machine to shape the side sheet metal walls of the body member in order to obtain a hollow form reinforcing flanged rim and if necessary other expansions of the sheet metal to form the final truncated cone shaped container; and thereupon causing the container to undergo appropriate finishing operations.

15. A method of manufacturing a hollow sheet metal container as claimed in claim 1 and substantially as hereinbefore described.

16. A hollow sheet metal container made by the method of any one of the preceding claims.

17. A hollow sheet metal container substantially as hereinbefore described with reference to and as illustrated in Figs. 14 and 14A; 15 and 15A; 16, 16A, 16B; or Fig. 19 or Fig. 20 of the accompanying drawings.

Amendments to the claims have been filed, and have the following effect: (a) Claims 1 & 2 above have been deleted or textually amended.

(b) New or textually amended claims have been filed as follows: (c) Claims 3 - 17 above have been re-numbered as 2 - 16 and their appendancies corrected.

1. A method of manufacturing a hollow sheet metal container comprising the steps of providing an annular sheet metal body member, and folding and shaping the top part of said body member to form an annular reinforcing flanged rim located externally and radially outwardly of the remaining portion of said body member but materially integral with said remaining portion, wherein during the formation of the reinforcing flanged rim the top part of the side sheet metal wall of the body member is bent outwards and downwards, and then an upper peripheral fold is pressed and shaped so as to form with it a peripheral hollow rib, a compound reinforcement and support made of a least three folded sections being arranged around the rest of the unified side wall of the body member, and placed around the upper peripheral rim of the body member where a lid of the container is to be fitted, a corner of one of said folded sections serving as a means of support and a place for levering off a lid fitted to the container.