GB2033880A

GB2033880A - Method of, means for and apparatus for sealing open-topped containers

Info

Publication number: GB2033880A
Application number: GB7933466A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-10-11
Filing date: 1979-09-27
Publication date: 1980-05-29
Also published as: SE7907626L; FR2438597B1; DE2844374A1; SE438655B; DK415679A; IT1166321B; NO792914L; FI793070A; IT7983469A0; FR2438597A1; LU81721A1; CH642315A5; BE879240A; NL7906925A; GB2033880B

Abstract

An open-topped container is fitted with an edge rim 1, having a bead 9 on its lower edge, by double flanging, the bead 9 abutting the inner wall of the container and thereby ensuring that inner retaining surface 11 thereof is maintained in substantially cylindrical configuration. Lid 12 is pressed into the rim 1 and then impressions 18a, 18b, 18c, &c are formed in the side wall 14 of the lid below the rim 1 to removably retain the lid in place. Apparatus for forming the impressions comprises a plurality of jaws 52a, 52b etc. radially displaceable by means of respective levers 67a, 67b etc. which are held against a pressure transfer element 69 on a vertically reciprocable ram 30 by means of a spring 71. <IMAGE>

Description

SPECIFICATION A method of, means for and apparatus for sealing open-topped containers This invention relates to a method of sealing opentopped containers such as buckets or tins wherein an edge rim is applied to the upper edge of the container wall and a lid provided with a cylindrical or substantially cylindrical side wall, is inserted into the rim and to means for, and apparatus for sealing such containers.

Previously known closures for open-topped containers such as buckets or tins, especiallyfor paint, having edge rims whose inner walling is shaped to be inclined slightly outwardly, in order to facilitate introduction of the lid, do not guarantee a sufficiently secure seal. In the event of slight shock stresses, for example in the event of being dropped from a slight height, the lid automatically comes loose and the contents of the container can escape, or air can get into the container to spoil its contents.The problem underlying the present invention is to provide the prerequisites for effective sealing, which is simple and inexpensive to carry out, of opentopped containers, and minimises the possiblity of inadvertent opening of the lid and escape of the container's contents or access of air thereto even in the event of shocks and fairly strong stressing of the container.

With this object in view, the present invention provides a method of sealing an open-topped container such as a bucket or tin, wherein an edge rim is applied to the upper edge ofthe container wall and a lid, provided with a cylindrical or substantially cylindrical side wall, is inserted into the rim, characterised in that impressions are introduced into the side wall ofthe lid, after its insertion into the border ring, from the interior of the lid, in such a way that the impressions adjoin the lower edge of the edge rim or are disposed therebelow.

The lower edge of the edge rim is preferably provided with a bead.

Because of the presence of the impressions, undesired opening ofthe lid is reliably avoided.

Understood by the term "inside" in this specification is, in each case, the region which, related to the container wall or lid wall, faces the interior hollow space in the container or lid. To be understood by the term "outside" are the regions which are opposite, related to the container wall or lid wall.

Understood by the term "upper side" of the container is that side which, upon filling of the same with fluid contents and prior to sealing ofthe lid, faces upwardly, irrespective of the position which this side assumes after the lid has been sealed.

It is particularly advantageous if the impressions are produced by outward pressing operation acting perpendicularly on the side wall of the lid, of at least parts of the lid. The impressions can, in accordance with a first embodiment, be applied so as to extend around the entire periphery of the lid. In accordance with a further embodiment which permits the performance of the impressing in a particularly simple manner, the impressions are introduced at discrete intervals from one another around the periphery of the lid. In this case, too, one achieves an exceilent hold which prevents undesired or unintentional opening of the lid.

In relation to the stability of the retention of the lid, it is of particular advantage if the impressions are introduced at the transition of the cylindrical side wall into a base region ofthe lid. To improve the seal, a sealing agent can be introduced between the lid and the edge rim prior to the sealing of the container.

A particularly effective seal (or closure) is obtained if, prior to the introduction ofthe impressions, the lid is held with at least one region, bordering the cylindrical side surface upwardly and projecting outwardly in step-like manner, in abutment against an outwardy-directed shoulder which adjoins or is contiguous to the cylindrical retaining surface, of the edge rim.

The invention furthermore provides means for sealing an open-topped container such as a bucket or tin, comprising a border ring mounted on the upper edge of the container wall, and a lid which is insertable into said rim and which is provided with a cylindrical or substantially cylindrical side wall, more especially for carring the above-described method into effect, which is characterised in that the edge rim has a cylindrical retaining surface which faces the cylindrical side wall ofthe lid and which is supported at its lower end on the container wall, and in that the side wall, extending cylindrically as far as the bottom of the lid when the lid has still not yet been sealed, ofthe lid is bounded upwardly by at least one outwardly-stepped region in which the axial height of the cylindrical side wall of the lid from the said stepped region to the base of the lid is greater than the axial height of the cylindrical retaining surface of the edge rim. As a result of the cylindrical formation (which contrasts with the known devices) of the retaining surface and the supporting thereof at the lower end, the result is achieved that a tight seal between the retaining surface and the confronting cylindrical side wall of the lid is ensured, even if impressions are formed in that region of the side wall which protrudes under the cylindrical retaining surface when the lid is closed.Undesired drawing-inwards of the lid, upon the formation ofthe impressions is prevented by the outwardly-stepped region of the lid, which is supported on the upper edge of the retaining surface of the edge rim.

The stability of the edge rim and accordingly also ofthe retaining surface which enters into engagemenu with the cylindrical side wall ofthe lid is increased if an outwardly-facing encircling bead is situated at the lower end of the retaining surface, which bead extends as far as the inside of the container wall. Such a bead is simple to produce by rolling-in the end region of the retaining surface.

The inherent stability of the edge rim can be further improved if this has, at the upper edge of the retaining surface, an outwardly-directed offset or shoulder which forms an acute to right angle with the adjoining upper edge of the container. Then, upon the application of the lid or formation of the impressions, the edge rim is prevented from being expanded and forced outwards. If the edge rim could be expanded or forced outwards this could lead to leaks in the seal and could, for example, occur if the said angle were to be greater than 90".

The edge rim is preferably connected to the upper edge of the container by doubled flanging which increases the stiffness of the container and also of the seal region.

The outwardly-stepped region of the lid, which prevents too great a penetration of the lid, advantageously extends continuously around the lid, which also improves the stability. For the same purpose, the lid may be bent over or beaded above the outwardly-stepped region, which is preferably effected.

The lid advantageously consists, at least in the lower part of its side wali, of a permanentlydeformable material. If this is sheet metal, the impressions can be brought about by cold working.

If use is made of piastics materials, the applicaton of heat during the formation of the impressions may be advantageous.

The invention moreover apparatus suitable for use in sealing an open-topped container such as a bucket or tin, of the kind described above, by means of a lid which has a cylindrical or substantially cylindrical side wall and which is insertable into an edge rim which is present at the upper edge of the container opening, and more especially serves for carrying the method of the invention into effect. The apparatus is characterised in that it comprises at least two jaws insertable into the interior of the lid and displaceable in the direction of the side wall thereof, and which carry, at their front ends, embossing or impressing tools or are designed as such tools, at least two jaws being arranged in such a way that, upon pressing thereof against the side wall of the lid, a force component of one jaw is directed oppositely to a force component of at least one other jaw.If a thermopiastic plastics material is used as the material for the lids, the embossing tools are preferably heated.

The jaws, and therewith the embossing tools, are advantageously distributed uniformly around the entire periphery of the lid and/or are displaceable in a common plane by a common actuating device.

Suitable for this purpose is particularly a piston or ram which acts in a direction extending perpendicular to the plane of displacement of the jaws. This piston or ram is preferably connected to the jaws by way of levers, which are hingedly fastened to the respective jaws and are mounted swingably on the piston or ram. It is particularly advantageous if the levers are rounded at their ends facing the piston or ram and are accommodated in at least one correspondingly-rounded externally-concave pressure transfer element which, upon the piston or ram being shifted downwardly, shifts outwardly the respective levers and the respective jaws hinged thereto.

Return of the jaws is advantageously effected by means of at least one return spring which engages into a groove in each of the levers.

Advantageously the piston or ram be lowered to such an extent that it brings about initial introduction of the jaws into the lid, placed loosely onto a container, then pressing-in of the lid into the edge rim and, after completion of this operation, pressingapart of the jaws. This is effected preferably by means of a hydraulic or pneumatic actuating device.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a radial section through a ring member which serves to form an edge rim of an open-topped container; Figure 2 is a view similar to Figure 1 showing the ring member having been further worked in the formation ofthe edge rim; Figure 3 is a view similar to Figures 1 and 2, but showing the finished edge rim; Figure 4 is a fragmentary radial section, comparable with Figure 3 and showing the edge rim having been fastened to the upper edge of an open-topped container in the form of a bucketortin; Figure 5 is a view similar to Figure 4 but showing the container sealed by a iid, which is prevented from being opened inadvertently by means of impressions formed in the lid;; Figure 6 is a diagrammatic front view of a preferred embodiment of apparatus, shown shortened in height, for sealing containers by means of an edge rim and lid, inserted into the edge rim as shown in Figure 5.

Figure 7 is a partially-sectioned elevation, to an enlarged scale of the region, indicated at VII in Figure 6, of the apparatus shown there, the left-hand and the right-hand halves showing two different embodiments respectively in different operating states; and Figure 8 is a partially-sectioned plan view of part of the apparatus of Figure 7.

Figures 1 to 3 show successive production stages of an edge rim 1 which, starting from a planar, annular shaped sheet-metal ring member which is not illustrated in the drawings, is formed by drawing and bending in cold working operations. In this working, initially an inner region, which occupies about 2/3 of the overall radial width of the sheetmetal ring member is bent over. During this operation, care is taken that the first portion 3, adjoining the remaining ring part 2, extends downwardly and is bent at right angles to the ring part 2. Linking the first portion is a frusto-conical piece 4 which extends inwardly at an angle of about 45 . The iengths of the pieces 3 and 4 are approximately the same and in each case somewhat less than about one-sixth of the entire width of the sheet-metal ring. Linking to the piece 4, which extends obliquely inwardly, in a part 5 which extends downwardly perpendicularly to the ring part 2 and whose lower end 6, as is shown in Figure 2, is widened outwardly. The ring, which is relatively unstable in Figure 1 configuration, is thereby already given a certain inherent stability.

In a further operation phase, the final shape, shown in Figure 3, of the edge ring 1 is produced. In this, on the one hand the outer edge of the still-remaining ring part 2, as indicated by the reference number7, is bent downwardly. Simul taneouslytherewith there is effected an upsetting or compression ofthe ring, the result of which is that the piece 4, initially extending at an angle of 45" of the adjoining sheet-metal parts 3 and 5, now extends approximately perpendicularly thereto. In this way there arises an offset 8 which encircles the entire edge rim. Simultaneously with this, the widened lower edge 6 is rolled-overto form a bead 9.The bead 9 is so dimensioned that, upon fitting of the edge rim 1 to an open-topped container such as a bucket, of which in Figure 4 merely the wall loins shown, it supports the lower end of the edge rim 1 inwardly against the wall 10 in such a way that retaining portion 11,formed bythe rest ofthe part 5, forms a cyclindrical opening which is circularcylindrical in configuration, in the illustrated example.

The fastening of the edge rim 1 on the edge of the container is effected by superimposing and subsequent doubled flanging, as is shown in section by Figure 4. In so doing, the piece 3 of the edge rim is pressed against the inside of the wall 10.

After the container has been fitted, in the abovedescribed manner, with the edge flange, and in the appropriate circumstances after filling of the container with its contents, e.g. with paint, a lid 12 is inserted into the edge flange 1.

The lid 12 (see Figure 5) consists of a substantially plane or flat base part 13 and a cylindrical side wall 14 which protrudes perpendicularly upwards from the latter prior to the insertion and sealing ofthe lid, as indicated by the dotted line at the bottom left hand side of the lid in Figure 5. The cylindrical side wall 14 is bounded upwardly by a region 15 which extends around the lid 12 and which protrudes outwardly in stepshaped manner and linking to which is an outwardly and downwardly bent-over or rolled-on gripping edge 16 which extends above the double-flanged part of the edge rim.

The outside diameter of the cylindrical side wall 14 corresponds to the inside diameter ofthe part, designed as a retaining surface 11, of the edge rim 1.

The width b1 ofthe cylindrical side wall 14 is greater than the width b2 of the retaining surface 11. The region 15 which protrudes outwardly in step-shaped manner is so dimensioned that, upon an introduction of the lid 12 into the opening bounded by the retaining surface 11, it forms, in collaboration with the offset 8, a stop which prevents any further insertion of the lid 12. A sealing agent may be introduced between the retaining surface 11 and the cylindrical sidewall 14, as indicated by the reference numeral 17.

As soon as the lid 12 has been fully inserted into the opening, bounded by the retaining surface 11, of the edge rim, at the bottom in the cylindrical side wall 14, and from the inside, impressions 18a, 18b, 18c, and so on, are applied, which impressions permanently deform the material ofthe lid in such a way that it bulges (or becomes dented) radially outwardly, as indicated by the reference number 19.

As a result of the cylindrical side wall 14 being designed to be wider in comparison with the retaining surface 11, the result is achieved that the impressions are positioned underthe lower edge of the edge rim 1. In the illustrated case, the impressions are directly contiguous to the bead 9. The impressions in themselves prevent the border ring from being buckled, and the sealing effect between the retaining surface 11 and the cylindrical side wall 14 from being disturbed.

The above-described procedure of the sealing and apparatus serving to carry the sealing into effect will now be described in more detail hereinunder with reference to Figures 5 to 8. The apparatus, shown in Figures 6 to 8, for sealing the containers comprises a base plate 20. Held on the base plate 20 are columns 21 and 22, which carry a guide plate 23. Mounted above the guide plate 23 are further columns 24 and 25 which carry a mounting plate 26. Fastened in the centre of the mounting plate 26 is a pressure fluid source 27, indicated merely schematically, for a pressure fluid which acts on a double-acting piston or ram 30, accommodated between the guide plate 23 and the mounting plate 26 in a housing 29, byway of a line 29 with a hydraulic or pneumatic pressure fluid.The movement of the piston or ram 30 is brought about, in a manner which is known 'per se' and which is not shown in more detail, by control lines and valves which are provided in the housing 28. The piston or ram 30 serves, by way of guide rods 31a and 31b, to raise or lower a sealing and embossing head 32 in the directions indicated by the arrow 33. Designated by the numeral 34 is a cover of the piston or ram 30.

The sealing and embossing head 32 comprises a solid supporting plate 35 having a central bore, in which a guide sleeve 37 is accommodated. The piston or ram 30 is guided so as to be slidingly displaceable in a guide sleeve 37. Passage bores 38 and 39 situated laterally on the supporting plate 35 serves make possible shifting of the supporting plate 35 along guide rods 31a and 31b, sliding of the supporting plate off these guide rods being prevented by nuts 40 and 41 which are screwed on the ends of the rods. A tube piece 52 is fastened (in the depicted instance by welding) to the underside of the guide plate 35 and centrally to the central bore.

The length of the tube piece 42 corresponds to some extent to the stroke height of the raising and lowering movement carried out by the sealing and embossing head 32. Fastened (in the depicted instance also by welding) to the lower end of the tube piece 42 is a ring-circular plate 43. This plate 43 is sunk into the surface of a block 44, the side wall of which is in alignment with the edge ofthe plate 43.

The plate 43 and the block 44 are connected by screws 45 and 46 which penetrate the plate 43. The block 44 contains a central bore 47 in which an extension 30a ofthe ram or piston 30 is slidingly displaceable. The extension 30a ofthe ram or piston 30 is screwed onto this by means of a threaded connection which is indicated by the reference numeral 30b, in which respect a disc 48 is mounted between the two parts, the diameter of which disc 48 is greaterthanthe diameter ofthe central bore 47.A corresponding disc 49 is fastened to the lower end of the extension 30a. Upon downwards movement of the ram or piston 30, the disc 48 comes into abutment against the upper side of the block 44, or against the bottom of a recess provided therefor, in which case, upon further downwardly ensuing movement of the punch 30, it forces the block 44 downwards. This state is shown in the right-hand part of Figure 7. Conversely, upon raising of the piston or ram 30, disc 49 fastened to the lower end of the extension 30a comes into abutment against the underside of a block 44 which is provided in this region with a concave configuration, and lifts this as well. This state is shown in the left-hand part of Figure 7.

The block 44 contains, in its lower region, an annular or disc-like adjoint-piece 50 the outside diameter of which corresponds approximately to the outside diameter of a lid 51 which is only indicated schematically and with which an open-topped container, for example a bucket corresponding to Figure 5, is intended to be sealed with the aid of the apparatus. On the underside of the adjoint-piece 50 there is a series of jaws 52a,52b,52c arranged so as to be displaceable each in the respective radial direction in a plane extending perpendicularly to the longitudinal axis of the piston or ram.

In the exemplified embodiment shown in the right-hand part of Figure 7, jaw 52e is designed as an embossing tool at its outwardly-directed front side, in the lower region thereof. For this purpose, it has a corresponding knife-edge-like projection 53, which is arcuately shaped in accordance with the peripheral contour of the lid. Upon the jaw being shifted outwardly, as shown in the right-hand part of Figure 7, the projection 53 produces an impression 54 in the side wall of the lid 51.

The jaw 52a shown in the left-hand part of Figure 7 carries, at its outwardly-facing end, an embossing tool 55 which is releasably connected to the jaw 52a by means of a countersunk screw 56 and two guide pins 57 and 58 (see Figure 8). This embodiment has the advantage that the embossing tools, which are subject to wear, are exchangeable without the jaws themselves being affected. The jaws are arranged in a star-like configuration at equal angular distances from one another about the longitudinal axis of the piston or ram 30, which can best be appreciated from Figure 8. As can be seen, in this embodiment, the jaws are back-off or bevelled at their rearward ends, so that they can be arranged closely adjacent one another.

Guidance of the jaws and location thereof in abutment against the underside ofthe disc-like adjoint-piece 50 is effected by screws 59 and 60, guided in slots 61 extending parallel to the jaw central axis and penetrating the adjoint-piece 50.

These screws 59, 60 extend vertically downwards from the upper side of the adjoint-piece 50 through the slots 61 in the latter and into threaded bores 62 extending downards into the jaws from the upper surfaces thereof. The risk of a canting or tilting of the jaws, during their longitudinal displacement, is avoided by a use of small-plate-like distance pieces 63 which are arranged on the upper side of the adjoint-piece 50 and which each contain, at a definite spacing from one another, respective bores for the two screws 59 and 60 associated with the respective jaw. These distance pieces also serve to protect the slots 61 against entry of impurities.

Each jaw has, centrally of its rearward region, a respective slot-like recess 64. This recess 64 is penetrated, towards its end facing the front side of the jaw, by a respective pivot pin 66, which is accommodated in a respective transverse bore 65 through the jaw. As can be seen more especially from Figure 8, each such bore 65 is arranged in such a way that it is intersected by the respective bores 62 for the corresponding screws 59 and 60 which therefore prevent lateral escape of the pivot pin 66.

Swingably mounted on the pivot pins 66 are respective levers 67a, 676, the widths whereof correspond to the respective recesses 64. As emerges more especially from Figure 8, these levers radially towards the longitudinal axis of the piston or ram 30. At their inner ends, the levers 67a, 676, & c are provided with rounded heads 68 which are accommodated in a correspondingly-shaped externally-concave pressure transfer element 69. This pressure transfer element 69 consists of a ring, made from an abrasion-resistant material, which is held on the underside of extension 30a of the piston or ram 30 beneath the disc 49.

The levers 67a, 676,... are, moreover, provided with slots 70 which extend obliquely towards the centre of the arrangement and in which there is engaged an annular spring 71 which urges the levers into abutment against the pressure transfer element 69.

The lengths of the levers 67a are fixed in such a way that, with the piston or ram 30 completely lowered and with the disc 48 abutting against the upper side of the block 44, they are disposed substantially horizontally, i.e. in alignment with the plane of displacement of the jaws, as is shown in the right-hand part of Figure 7. When the jaws are retracted, the inwardly-facing ends of the levers are slightly raised, as is shown in the left-hand part of Figure 7.

An outer cover for the sealing and embossing head 32 is designated by the reference numeral 72.

Upon the operation of the apparatus a container which is to be sealed, and which is provided with an edge rim, is arranged on the base plate 20 in such a way that its central axis is in alignment with the longitudinal axis of the apparatus i.e. of the piston or ram 30. Then, a lid is positioned in the edge rim of the container. Thereupon, the piston or ram 30 is acted upon by pressure fluid and thereby is lowered.

As this occurs, the sealing and embossing head 32 is introduced into the interior of the lid until it butts against the base thereof. Upon further downward displacement of the piston or ram 30, the sealing and embossing head forces the lid into the edge rim, until the lid butts, by its step-shaped outwardlyprojecting region 15, against the offset 8. Further downward shifting of the piston or ram 30 causes, by way of the extension 30a, the pressure transfer element 69 and the rounded heads 68 of the levers 67a, shifting of the levers so that the jaws and the embossing tools mounted at their outer ends are moved outwardly. After completion of the embossing operation, raising of the piston or ram 30 brings about retraction of the jaws and of the embossing tools fastened thereto, and as soon as the disc 49 butts against the underside of the block 44, the sealing and embossing head 32 is raised out of the lid of the sealed container. During this operation, the spring 70 prevents the heads 68 of the levers from disengaging from the pressure transfer element 69.

In the illustrated example, an arrangement having eight jaws has been described. It is, however, of course possible to construct the apparatus in a corresponding manner, but with a different number of jaws. The drive of the piston or ram does not necessarily have to be effected hydraulically or pneumatically. It can be effected about by any suitable mechanical drive arrangement.

Claims

1. A method of sealing an open-topped container, such as a bucket or tin, wherein an edge rim is applied to the upper edge of the container wall and a lid, provided with a cylindrical or substantially cylindrical side wall, is inserted into the rim, characterised in that impressions are introduced into the side wall of the lid, after its insertion into the border ring, from the interior ofthe lid, in such a way that the impressions adjoin the lower edge of the edge rim or are disposed therebelow.

2. A method as claimed in claim 1 wherein the lower edge of the edge rim is provided with a bead.

3. A method as claimed in claim 1 or 2 characterised in that the impressions are produced by an outwards pressing operation acting perpendicularly on the side wall of the lid, or at least parts thereof.

4. A method as claimed in claim 1,2 or 3 characterised in that the impressions are applied around the entire periphery of the lid.

5. A method as claimed in 1,2 or 3 characterised in that the impressions are introduced at discrete intervals from one another around the periphery of the lid.

6. A method as claimed in any preceding claim, characterised in that the impressions are introduced at the transition of the cylindrical side wall into a base region of the lid.

7. A method as claimed in any preceding claim, characterised in that, priorto the insertion of the lid, a sealing agent is introduced between the edge rim and the lid.

8. A method as claimed in any preceding claim, characterised in that, upon the introduction of the impressions, the lid is held with at least one region, bordering the cylindrical side surface upwardly and protruding outwardly in step-like manner, which adjoins a cylindrical retaining surface, of the edge rim.

9. Means for sealing an open-topped container such as a bucket or tin comprising an edge rim mounted on the upper edge of the container wall, and a lid which is insertable into said rim and which is provided with a cylindrical or substantially cylindrical side wall, characterised in that the edge ring has a cylindrical retaining surface which faces the cylindrical side wall of the lid and which is supported at its lower end on the container wall, and in that the side wali, extending cylindrically as far as the bottom of the lid when the lid is still not yet sealed, of the lid is bounded upwardly by at least one outwardlystepped region in which the axial height (b1) of the cylindrical side wall of the lid from the said stepped region to the base of the lid is greater than the axial height (b2) of the retaining surface of the edge rim.

10. Means as claimed in claim 9, characterised in that an outwardly-projecting encircling beam is situated at the lower end ofthe retaining surface, which encircling bead extends as far as the inside of the container wall.

11. Means as claimed in claim 9 or 10, characterise in that the edge rim has, at the upper edge of the retaining surface, an outwardly-directed offset which forms an acute to right angle with the adjoining upper edge of the container.

12. Means as claimed in claim 9,10 or 11 characterised in that the edge rim is connected to the upper edge ofthe container by doubled flanging.

13. Means as claimed in any of claims 9 to 12, characterised in that the outwardly-stepped region ofthe lid extends continuously around the lid.

14. Means as claimed in any of claims 9 to 12, characterised in that the lid is bent over or beaded above the outwardly-stepped region.

15. Means as claimed in any of claims 9 to 13, characterised in that the lid consists, at least in the lower part of its side wall, of a permanentlydeformable material.

16. Apparatus for sealing an open-topped container such as a bucket or tin, by means of a lid, insertable into an edge rim fastened to the upper edge ofthe container opening, said lid having a cylindrical or substantially cylindrical side wall, preferably as claimed in any of claims 9 to 15 and more especially for carrying out a method claimed in any of claims 1 to 9, characterised in that it comprises at least two haws insertable into the interior of the lid and displaceable in the direction of the side wall thereof, and which carry, at their front ends, embossing or impressing tools or are designed as such tools, at least two jaws being arranged in such a way that, upon pressing thereof against the side wall of the lid, a force component of one jaw is directed contrary to a force component of at least one other jaw.

17. Apparatus as claimed in claim 16, characterised in that the jaws are distributed uniformly around the entire periphery of the lid and/or are displaceable in a common plane by an actuating device.

18. Apparatus as claimed in claim 16 or 17, characterised in that the jaws are displaceable in a common plane by a piston or ram which is actuatable perpendicularly to their direction of displacement.

19. Apparatus as claimed in claim 18, characterised in that the piston or ram is connected to the jaws by way of levers which are hingedly fastened to each of the jaws and are mounted swingably on the piston or ram.

20. Apparatus as claimed in claim 19, characterised in that the levers are rounded at their ends facing the piston or ram and are accommodated in at least one correspondingly-rounded, externallyconcave pressure transfer element which, upon the piston or ram being shifted downwards, shifts outwardly the respective levers and the respective jaws hinged thereto.

21. Apparatus as claimed in any of claims 16 to 20, characterised by at least one return spring which engages into a groove in each of the levers.

22. Apparatus as claimed in any of claims 18 to 20, characterised in that the piston or ram can be lowered to such an extent that it brings about initial introduction of the jaws into the lid placed loosely onto a container, then pressing-in of the lid into the edge rim, and, after completion of this operation, pressing-apart of the jaws.

23. A method of sealing an open-topped container substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

24. Means for sealing an open-topped container substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 5 of the accompanying drawings.

25. Apparatus for sealing an open-topped container substantially as hereinbefore described with reference to and as illustrated in Figure 6 to 8 of the accompanying drawings.