Container comprising a body and a cover

Abstract

The invention concerns a container having a barrel-like body and a fitting sealed lid which during transport and storage prevents contamination of the content, which permits multiple opening and closing without losses of sealing integrity and which manages without an elastomeric seal as an additional material component, which is distinguished in that at least in the braced condition the lid bears sealingly with respect to the body against at least two mutually spaced sealing locations which are peripherally continuous in an annular shape around the axis of symmetry of the container.

Description

I. FIELD OF USE

[0001] The invention concerns a container with a barrel-like body and a fitting, sealed lid.

II. TECHNICAL BACKGROUND

[0002] It is the usual practice nowadays for the homopolymers and copolymers of tetrafluoroethylene (TFE) in powder form to be put into barrel-like plastic containers or fiber drums, preferably with a pot-shaped body and a lid which fits thereon. The function of the containers is to protect the above-mentioned polymers which are frequently produced and processed under clean room conditions from dust and moisture as well as pressure loadings. Foreign substances of any kind, moisture and polymer particles which are compacted by a pressure loading, upon processing of the TFE polymers, result in flaws in the extrudates or molded bodies produced therefrom, which are not acceptable in particular when dealing with thin-gauge products such as wire coatings or films.

[0003] For high-quality end uses, plastic containers, for example comprising polypropylene, are preferred over fiber drums, for the packaging of polytetrafluoroethylene (PTFE) powders, because they afford a better surface quality and the operation of inserting an inner film or foil bag for protecting the powders can be avoided.

[0004] High demands of varying kinds are made on the plastic containers; they must afford sufficient sealing integrity, even when they are opened and closed a plurality of times. Moreover, in accordance with DE-U-9408630, they must withstand the loading pressure which occurs when in the filled condition they are stacked one upon the other, on the individual packaging units. In practice, between two and four pallet stacks are stacked one upon the other, which in turn are loaded with between two and three layers of containers. The containers are filled with between 20 and 50 kg of powder. Certain filling heights in the container should not be exceeded in the filling procedure as otherwise the powder can suffer from caking together and there is no guarantee of fault-free processing thereof.

[0005] Containers for PTFE powder in their technically complicated, high-quality configurations are preferably produced by injection molding. In that case, mass plastic materials such as polypropylene or polyethylene are used for reasons of price. As a high level of strength is required on the part of the containers for transportation and storage, even at temperatures of between −20° C. and 60° C., chemically modified propylene copolymers are preferably used as the material here. The packaging systems are of high value so that the aim is to achieve re-use, for example by cleaning and re-filling.

[0006] Quite particular demands are made on the sealing system for the containers for PTFE powder. In comparison with the known one-lid system, for example for paint, the packaging system disclosed in EP-B-362 959 is a round three-component system comprising the container body, the lid and a clamping ring. The sealing principle here provides that the upper part of the body terminates in an outwardly downwardly inclined configuration, whereas thin peripheral lugs in the inside edge of the lid are pressed on to the upper portion of the body by means of the clamping ring. The restoring moment of those peripheral lugs however is slight so that after the container has been first opened and re-closed, sealing integrity drops off severely. Re-use of the lid and recycling of the container is in practice not possible.

[0007] In addition, production of the thin sealing lips by means of the injection molding process is technically very expensive and susceptible to trouble as complicated and expensive venting means must be provided in the injection molding tool, for completely forming the thin sealing lips by the injection molding action. In the injection molding process for example polymer deposits can cause complete or partial clogging of the venting regions, which results in the thin peripheral lugs not being completely formed by injection molding, so that the sealing function is no longer guaranteed.

[0008] Similarly, that form of sealing arrangement with thin peripheral lugs at the inner edge of the lid is described in WO-A-96/37410, for a rectangular plastic container.

[0009] U.S. Pat. No. 4,674,650 describes a sealing arrangement for a round container of plastic material, comprising a container body, a lid and a clamping ring. The seal is made by a sealing ring which is additionally fitted in the lid and which seals off the outwardly disposed, inwardly directed body. Introducing an additional sealing ring comprising an elastic material suffers from various disadvantages: it makes the system more expensive, it causes increased difficulty in automatically cleaning off the packaging system prior to use, and upon disposal of the packaging system it has to be separated as an additional material component if the container material is to be fed to a recycling process.

[0010] In the case of a commercially available packaging system comprising a container body, a lid and a clamping ring, from Sulo Plast GmbH & Co KG, a seal is made by an elastomer seal, for example of polyurethane, being cast into a groove provided in the lid. That elastomer seal seals against the upper edge of the body. The essential disadvantage of that system is that the elastomer seal can be damaged under the loading pressure on the elastomer seal upon transportation and storage. Parts of the seal are detached and can pass into the PTFE powder to be protected. In this case also, the elastomer component has to be separated off if, after use of the packaging system, the container lids are fed to a recycling process.

III. SUMMARY OF THE INVENTION

[0011] a) Technical Object

[0012] The object of the present invention is to provide a container having a sealing means which excludes contamination of the content during transportation and storage, which permits multiple opening and closing without losses of sealing integrity and which manages without an elastomer seal as an additional material component.

[0013] b) Attainment of the Object

[0014] That object is attained by the characterising features of claim 1. Advantageous embodiments are set forth in the appendant claims.

[0015] The at least two sealing locations which are spatially separated from each other—and which are also in particular movable relative to each other—afford on the one hand a higher degree of sealing reliability and on the other hand, by virtue of the relative mobility of the sealing locations relative to each other, that is to say either the sealing legs which are active at the sealing locations or the sealing surfaces which press thereagainst—they afford a high probability that sealing integrity is achieved at both sealing locations.

[0016] By virtue of the pot-shaped container which is open at one end and the lid which fits thereon, the sealing locations are always of a peripherally extending closed configuration, irrespective of whether the basic shape of the container is round or polygonal.

[0017] Furthermore hereinafter the first sealing location is described in such a way that in that case the sealing surface (groove) is provided in the lid and the sealing leg or arm (upper edge of the wall of the body) is provided on the container, while that association is precisely the reversed in regard to the second sealing location (flange).

[0018] In regard to one or also all of the two sealing locations, the association of the sealing surface and the sealing leg with the body and the lid respectively may also be reversed, that is to say for example the free upper end of the edge of the body can be grooved in a V-shape, in which a suitable projection on the lid could engage.

[0019] By virtue of the high sealing probability for each individual sealing location, and thus definitely the high level of sealing certainty for the container by virtue of a plurality of separate sealing locations and the mobility relative to each other, it is possible to risk the body and the lid bearing against each other at the sealing locations directly, that is to say without the interposition of a special, more elastic sealing material, with the advantage of greater ease of recycling and a reduced risk of contamination of the contents due to constituents of the sealing material coming away.

[0020] By virtue of adequate axial spacing of the sealing locations, the distance can be put to use for length compensation purposes and thereby the sealing probability at both sealing locations can be enhanced. If in addition at least one of the sealing locations is divided into a plurality of partial sealing locations, that further enhances the sealing probability, even if the for example sealing legs of the partial sealing locations are not or scarcely movable relative to each other.

[0021] The following description only ever refers to the cross-sectional shapes of the corresponding locations on the lid and the body respectively. These however are always of a ring-shaped peripherally extending configuration, corresponding to the ring-shaped peripherally extending—round or polygonal or free-shaped—shape of the body, that is to say the peripheral walls thereof, when viewed in plan.

[0022] In a preferred embodiment the first sealing location comprises the free upper end of the edge of the body, in the form of a sealing arm or leg, on to which fits a groove which is of preferably V-shaped cross-section and which is provided in the underside of the lid. That groove region of the lid, which forms the groove, goes radially inwardly into the main portion of the lid, the central region, and on the outside into a connecting region which, on the outside of the wall, is directed parallel thereto or inclinedly, for example with an increasing spacing, in an outward and downward direction.

[0023] At the lower end, the connecting region forms a transition into a lid edge which is of a fork-shaped or U-shaped cross-section with downwardly facing free ends, being the sealing legs.

[0024] Those sealing legs can be pressed with their free ends against an upwardly facing sealing surface, by means of a clamping device, which represents the top side of a flange which projects outwardly from the wall of the body.

[0025] In this case, the sealing surface which extends peripherally in a ring shape and against which the sealing leg or legs bear, can extend horizontally, that is to say precisely perpendicularly to the longitudinal direction of the container, generally the axis of symmetry of the body and the lid, or inclinedly relative thereto, for example in such a way as to fall away radially inwardly, that is to say with an increasing spacing in the longitudinal direction with respect to the freely terminating edge of the body.

[0026] The lid and the body are pressed against each other, in particular at the two sealing locations, by a clamping device, frequently a clamping ring which embraces both the edge of the lid and also the adjacent flange of the body, in a radially inward direction.

[0027] In this case, the clamping ring has a radially inwardly open groove which is provided with inclined flanks and the inside surfaces of which become increasingly spaced from each other, from the bottom of the groove to the open end thereof, that is to say radially inwardly in the assembled condition thereof.

[0028] In the same manner the rear sides of both the edge of the lid and also the flange, which are remote from the sealing surface, are also of an inclined configuration.

[0029] The upwardly facing rear side of the edge of the lid thus falls away inclinedly downwardly from the inside outwardly, while the downwardly directed rear side of the flange rises inclinedly from the inside outwardly, corresponding to the inclination of the inside flanks of the clamping ring relative to each other.

[0030] In that case, the probability of the two sealing locations bearing sealingly against each other is greatly increased by mobility of the elements forming the two sealing locations, either on the part of the lid or on the part of the body.

[0031] In practice, the annular flange is arranged between 10 mm and 100 mm, in particular 30 mm, below the edge of the body, and projects radially outwardly between 10 mm and 50 mm, in particular 20 mm. The peripherally extending sealing legs which can be arranged on the annular flange of the body or at the edge of the lid are between 1 mm and 15 mm and in particular 3.5 mm high and between 1 mm and 10 mm and in particular 3 mm wide.

[0032] c) Embodiments

[0033] Embodiments in accordance with the invention—with different dimensional relationships between the lid and the edge of the body—are described in greater detail with reference to the Figures in which:

[0034] FIGS. 1 show the lid disposed on the body in the relaxed and in the braced condition with a large axial extent in respect of the lid,

[0035] FIGS. 2 show the lid disposed on the body in the relaxed and in the braced condition with a small axial extent in respect of the lid, and

[0036] FIG. 3 show a third variant of the container.

[0037] FIGS. 1 and 2 respectively show in section along the longitudinal axis, the axis of symmetry 10, of the body 1 and the lid 2, the contact thereof against each other, more specifically in FIGS. 1a and 2a with the lid loosely fitted on the body and in FIGS. 1b and 2b with the lid braced against the body, with a clamping ring 3 serving as the clamping device.

[0038] What is common to both the designs in FIGS. 1 and 2 is the basic configuration of the cross-sectional shape of the lid, in particular the edge of the lid, and the upper region of the wall of the body 1: both the lid and also the body, considered in plan, are symmetrical with respect to the axis of symmetry 10 which is intended at the same time to define the longitudinal direction, thereby forming peripherally closed containers, insofar as the single open end of the body can be sealingly closed by the lid. In general the body and the lid are rotationally symmetrical.

[0039] The wall 7 of the body 1 is preferably of a smooth-surfaced nature on the inward side, for more easily filling, emptying and cleaning the interior of the container.

[0040] On the outward side, set back from the freely terminating edge 1a of the body, the body has a peripherally extending annular flange 8 which projects radially outwardly.

[0041] The edge 1a of the body, that is to say the wall in particular above the annular flange, can be somewhat thicker in this respect than beneath the annular flange, but generally not thicker than 3 mm.

[0042] In cross-section in the radial region of the body edge 1a, the lid 2 is of a U-shape or a V-shape with an annular groove 6 which is open downwardly, that is to say towards the body, and with which the lid 2 can be laid on the edge 1 of the body.

[0043] Radially within that U-shaped or V-shaped groove region 2c, the lid forms a one-piece transition into a central region 2d which is thus set downwardly with respect to the groove region 2c. The radially outward limb of the groove region 2c is either prolonged in the axial direction or in an inclinedly outwardly enlarging configuration, by means of a connecting region 2b. The edge 2a of the lid is provided in one piece at the lower outer free end of the connecting region 2b. The edge 2a of the lid is thus still disposed under the central region 2d of the lid in the axial direction in the fitted condition.

[0044] The edge 2a of the lid has sealing legs 11b, 11c which face downwardly and which terminate freely and which also again extend peripherally in a closed configuration.

[0045] When the lid is braced with respect to the body, the sealing action is to be implemented at two different sealing locations 4, 5;

[0046] The freely terminating body edge 1a which bears against the lid in the groove 6 thereof represents the first sealing location 4. The sealing legs 11b, 11c of the 11d edge 2a, which bear against the top side of the annular flange 8 of the body, represent the second sealing location which is subdivided into two partial sealing locations 5a, 5b by the sealing legs 11b, 11c which extend in mutually concentric relationship.

[0047] The bracing action is effected by virtue of the fact that, at the second sealing location 5, the rear sides which respectively face away from the sealing location, more specifically the upwardly directed rear side 13 of the edge 2a of the lid and the downwardly directed rear side 14 of the flange 8, extend at an acute angle and come closer to each other as they extend in a radially outward direction.

[0048] The lid 2 is braced and sealed with respect to the body 1 by pushing on a clamping ring 3 with a suitably conical clamping groove 19 which is open in a radially inward direction and which is so dimensioned that, when the clamping ring 3 is pushed on, the clamping groove not only bears inwardly against the rear sides 13, 14 of the edge 2a of the lid and the flange 8, but also presses them against each other in the axial direction.

[0049] In that respect, it is inter alia of significance for the edge 2a of the lid with its sealing legs 11b, 11c to be relatively strong and stable in itself. The same applies in regard to the groove region 2c which for that purpose, in particular in the region of the bottom of the groove, can be of a wall thickness which is at least doubled in relation to the normal wall thickness for example of the central region 2d, and in addition has an extension portion 2e which affords an additional stabilising effect on the rear side of the groove, that is to say facing upwardly.

[0050] In contrast, the edge 2a of the lid is definitely movable with respect to the groove region 2c, for example by virtue of a reduced thickness of material in the configuration therebetween, in particular at the respective transitions between the groove region 2c and the connecting region 2b, and the connecting region 2b and the edge 2a of the lid.

[0051] In that way for example the lid edge 2a can be pivoted somewhat downwardly with respect to the connecting region or the entire connecting region can be pivoted somewhat radially inwardly with respect to the groove region.

[0052] It is also important for the edge 1a of the body, in particular the entire section of the wall 7 from the flange 8 to the free end, to be sufficiently strong and stable, and in particular to be thicker in wall thickness than the remainder of the wall 7, so that the edge 1a of the lid can admittedly be bent inwardly or outwardly at its free end in a radial direction, but only when a relatively large amount of force is applied.

[0053] The outwardly directed flange 8 is also of a very strong and stable nature, and in particular is stabilised by legs 15 which extend radially outwardly at the underside.

[0054] The clamping ring 3 comprises for example metal or plastic material and can be reduced in its diameter by tangentially fitted clamping screws, lever fasteners or others of the known possible options.

[0055] FIGS. 1 and 2 differ by virtue of the relationship of the spacings A and B respectively, to be defined hereinafter, in regard to the lid and the body:

[0056] Those spacings which are to be measured in the longitudinal direction, that is to say parallel to the axis of symmetry 10, are defined as follows in the unbraced rest condition of the body and the lid respectively: the spacing A in the case of the lid is the axial extent between the bottom of the groove 6 and the furthest downwardly projecting sealing leg 11b, 11c of the edge 2a of the lid.

[0057] The spacing B in the case of the body is to be the spacing between the free upper end of the edge 1a of the body and the upwardly facing sealing surface 12b of the flange.

[0058] While, as shown in FIG. 1, the spacing B is somewhat larger than the spacing A, this is precisely the opposite in FIG. 2a. Those differing relationships and the situations resulting therefrom can be deliberately selected or can occur by virtue of production tolerances in manufacture of the lid and the body respectively, which is generally implemented by an injection molding process.

[0059] If the lid spacing A is greater than the body spacing B, as in FIG. 1a, then when the lid is loosely fitted on to the body, the groove region 2c thereof sits with a flank or the bottom of the groove 6 on the free, upwardly facing end of the edge 1a of the body, without the downwardly facing sealing legs 11b, 11c of the edge 2a of the lid reaching the upwardly facing sealing surface 12b of the flange 8, the sealing surface 12b generally extending at a right angle to the axis of symmetry 10.

[0060] If in that case—by virtue of differences in diameter—the edge 1a of the body does not lie in the bottom of the groove 6 of the lid 2, but bears, spaced therefrom radially inwardly or preferably outwardly, against one of the flanks of the groove 6, the spacing between the edge 2a of the lid and the flange 8 at the second sealing location 5 becomes even greater.

[0061] As FIG. 1a shows, the lower free ends of the concentrically extending sealing legs 11b, 11c are not disposed in this case at one level, but, because of a slightly outwardly rising inclined position of the edge 2a of the lid and also a slightly downwardly outwardly facing inclined position of the connecting region 2b of the lid 2, the radially inwardly disposed sealing leg 11b extends somewhat further towards the sealing surface 12.

[0062] By fitting the clamping ring 3, that is to say moving it radially inwardly and thus causing the conical inside flanks of the clamping groove 19 of the clamping ring 3 to bear against the rear sides 13 and 14, which face outwardly from the clamping location 5, of the edge 2a of the lid and the flange 8 of the body 1, the edge 2a of the lid is on the one hand moved radially inwardly and on the other hand at the same time and/or instead thereof is urged axially against the sealing surface 12b of the flange, that is to say downwardly. That is effected by virtue of the mobility of the edge 2a of the lid with respect to the remainder of the lid 2, in particular with respect to the groove region 2c, and in particular by virtue of bending or turning of the individual parts of the lid, about the transitions 17 and 18, which are of smaller wall thickness, on both sides of the connecting region 2b.

[0063] Solely by virtue of the radially inward movement of the edge 2a of the lid and the approach of the transitional region 2b from the inclined position to the parallel position, with respect to the axial direction, at least one of the sealing legs 11b, 11c, with its free end, reaches the sealing surface 12b of the flange 8, whereby a sealing action is produced at that second sealing location 5. As shown in FIG. 1b, in that case the radially outwardly disposed sealing leg 11c bears with its entire end face against the sealing surface 12b while the radially inwardly disposed sealing leg 11b involves only line contact with the sealing surface 12b.

[0064] The axial movement of the edge 2a of the lid also provides that, at the first sealing location 4, the groove 6 and in particular the contact point thereof at the flank is pressed against the edge 1a of the body, and thus enhanced sealing integrity is also achieved at the first sealing location 4.

[0065] If in addition the sealing surface 12b does not extend perpendicularly to the axis of symmetry 10 but adopts a radially inwardly increasing spacing from the upper free end of the edge 1a of the body, with the contact point under some circumstances moving in the direction of the bottom of the groove and the edge 1a being slightly radially deformed, by virtue of an inclined positioning, as shown in broken line in FIG. 2b, that axial bracing effect is still further increased.

[0066] In contrast thereto, in FIG. 2a the spacing A of the lid 2 is greater than the spacing B of the body 1. When therefore the lid 2 is loosely laid on the body, the edge 2a of the lid lies on the sealing surface 12b of the flange 8 and, because of the weight of the lid, the edge 2a of the lid is thereby bent somewhat around the transition 18 to the connecting region 2b, so that only the radially inward sealing leg 11b will lie on the sealing surface and the radially outer sealing leg 11b will be lifted somewhat off the sealing surface 12b.

[0067] In addition, at the first sealing location 4, the bottom of the groove 6 will not reach the free end of the edge 1a of the lid, unless it is not aligned in the radial direction with the bottom of the groove but is displaced radially outwardly or inwardly and thus already bears against one of the flanks of the groove 6.

[0068] By virtue of the clamping ring 3 being fitted in a radially inward direction, the edge 2a of the lid is initially displaced radially inwardly along the sealing surface 12b and, when that happens, it additionally also provides that both sealing legs 11b, 11c of the edge 2a of the lid bear against the sealing surface 12b of the flange 8 of the body 1.

[0069] By virtue of that radially inward displacement, the connecting region 2b which adjoins the edge 2a of the lid is also displaced radially inwardly and thereby causes the edge 1a of the body to bear at least against the radially outer flank of the groove 6, and thus a sealing effect also occurs at that first sealing location 4.

[0070] A further possible option is shown in FIGS. 3a and 3b:

[0071] While in the structures shown in FIGS. 1 and 2 the wall thickness of the edge 1a of the body was markedly less than the width of the bottom of the groove 6 in the lid, the reverse is the case in the structure shown in FIG. 3:

[0072] The wall thickness of the edge 1a of the body, at least at the free end thereof, is so great that it cannot in any way penetrate into the groove 6 so far that the bottom of the groove is reached.

[0073] Thus, when the lid is loosely fitted, the edge 1a of the body already bears with its end region against both flanks of the groove 6 while the sealing legs 11 of the edge 2a of the lid still do not reach the sealing surface 12b of the flange 8. It is only by pushing on the clamping ring as shown in FIG. 3b that the edge 2a of the lid is pulled radially inwardly, in particular however also in an axial direction downwardly on to the sealing surface 12b against which the sealing legs 11b, 11c now bear. That axial bracing effect also causes the free end of the edge 1a of the body to be pushed further into the groove 6 and also expanded slightly—depending on the respective stability of the groove region 2c. On the radially inward side, that results in slight deformation of the central region 2d of the lid to afford a cambered shape while on the radially outward side it results in inclined positioning of the outer limb of the groove region 2c and the connecting region 2b.

[0074] That however is compensated by radially inward displacement of the edge 2a of the lid by the clamping ring 3, and the existing mobility of the edge of the lid with respect to the groove region 2c by virtue of the longitudinal extent of the connecting region 2b and/or the mobility afforded by virtue of the reduced-thickness transitions 17 and/or 18 of the connecting region 2b with respect to the adjoining regions. 1 List of references  1 body  1a edge of the body  2 lid  2a edge of the lid  2b connecting region  2c groove region  2d central region  2e extension portion  3 clamping ring  3a groove  4 sealing location  5a, b partial sealing location  6 annular groove  7 wall  8 annular flange  9 10 axis of symmetry 11a, b, c sealing leg 12a, b sealing surface 13 rear side 14 rear side 15 legs 16 bottom 17 transition 18 transition 19 clamping groove A = lid spacing B = body spacing

Claims

1. A container comprising a body (1) and a lid (2), as well as a clamping device for sealingly bracing the lid (2) with respect to the body (1), characterised in that at least in the braced condition the lid (2) bears sealingly with respect to the body (1) against at least two mutually spaced sealing locations (4, 5) which are peripherally continuous in an annular shape around the axis of symmetry (10) of the container.

2. A container as set forth in claim 1 characterised in that the body (1) and the lid (2) each only consist of a single material, in particular plastic material, in particular the same plastic material.

3. A container as set forth in one of the preceding claims characterised in that the sealing locations (4) and (5) are arranged axially spaced from each other.

4. A container as set forth in one of the preceding claims characterised in that the sealing locations (4) and/or (5) are divided into partial sealing locations (5a, 5b).

5. A container as set forth in one of the preceding claims characterised in that at the sealing locations (4) and (5) or the partial sealing locations (5a, 5b)respectively a sealing leg (11) presses with its outside surface, in particular with line contact, against a sealing surface (12) and is movable along said sealing surface (12) by virtue of the bracing effect by means of the clamping device.

6. A container as set forth in one of the preceding claims characterised in that at the first sealing location (4) the sealing leg (11a) is the freely ending edge (1a) of the body and the sealing surface (12a) is an annular groove (6) of V-shaped cross-section in the underside of the lid (2).

7. A container as set forth in one of the preceding claims characterised in that at the sealing location (5) the sealing surface (12) is an annular surface, which extends transversely with respect to the axis of symmetry (10) and which is arranged outside the wall (7) of the body (1), on a radially outwardly facing annular flange (8), and the sealing leg (11b) is a sealing leg which extends peripherally in a ring configuration and which is provided in one piece with the outer edge (2a) of the lid.

8. A container as set forth in claim 7 characterised in that the edge of the lid has two radially spaced, mutually concentrically arranged sealing legs (11b, 11c) which bear against the same sealing surface (12b) in the braced condition.

9. A container as set forth in one of the preceding claims characterised in that the edge (2a) of the lid, at least in the connecting region between the sealing legs (11b, 11c), is of such a stable nature that no substantial deviation from the annular shape of the edge (2a) of the lid can be produced by clamping of the clamping device.

10. A container as set forth in one of the preceding claims characterised in that the sealing surface (12b) extends perpendicularly to the axis of symmetry (10).

11. A container as set forth in one of the preceding claims characterised in that the sealing surface (12b) is arranged at an acute angle, in particular, in the case of a sealing surface (12b) facing towards the open end of the body (1), in such a way as to fall away radially inwardly towards the bottom of the body (1).

12. A container as set forth in one of the preceding claims characterised in that considered in cross-section the lid (2) comprises radially outwardly a plate-shaped central region (2d), a groove region (2c) which is curved up axially outwardly in a U-shape, an annular connecting region (2b) adjoining the radially outward free end of the groove region, and the adjoining edge (2a) of the lid, which are provided in one piece with each other, and wherein the transition between the connecting region (2b) and at least one of the adjoining regions is of a smaller wall thickness than the other regions.

13. A container as set forth in one of the preceding claims characterised in that the edge (2a) of the lid is arranged radially outside the connecting region (2b).

14. A container as set forth in one of the preceding claims characterised in that the connecting region (2b) extends axially.

15. A container as set forth in one of the preceding claims characterised in that the annular groove (6) has a half-round bottom and the bottom of the groove is wider than the wall thickness of the body edge (1a) which is also rounded.

16. A container as set forth in one of the preceding claims characterised in that the free end of the edge (1a) of the body in the form of a sealing leg (11a) of the first sealing location (4) assumes, from the sealing surface (12b) of the second sealing location (5), an axial spacing which is slightly larger than the bottom of the annular groove (6) from the free end of the sealing leg (11) or (11b) and (11c) in the unstressed condition of the lid.

17. A container as set forth in one of the preceding claims characterised in that the diameter of the body (1), measured from the wall center to the wall center at the free end, that is to say at the edge (1a) of the body, differs from the diameter of the annular groove (6) of the lid (2), measured from the center of the bottom of the groove to the center of the bottom of the groove, and in that respect the diameter of the body is preferably greater than the diameter of the annular groove (6) so that when the lid is fitted without bracing the lid is supported with its outer flank of the annular groove on the edge (1a) of the body.

18. A container as set forth in one of the preceding claims characterised in that the clamping device is a clamping ring (3) with a radially inwardly directed groove (3a) whose flanks move away from each other towards the free inner end.

19. A container as set forth in one of the preceding claims characterised in that the rear side (13) of the edge (2a) of the lid, which faces away from the flange (8), and the rear side (14) of the flange (8), which faces away from the lid, are shaped conically corresponding to the internal flanks of the annular groove (3a) of the clamping ring (3).

20. A container as set forth in one of the preceding claims characterised in that the conical rear side of the flange (8) of the body (1) is formed at least by legs (15) of the flange (8), which are arranged distributed over the periphery.

21. A container as set forth in one of the preceding claims characterised in that the wall thickness of the body (1) at the edge (1a) of the body, in particular from the flange (8) to the free end, is greater than between the flange (8) and the bottom (16) of the body.

22. A container as set forth in one of the preceding claims characterised in that the annular groove (6) has an intermediate angle between its outer flank (6a) and its inner flank (6b) of 5-50°, in particular 10-30°.

23. A container as set forth in one of the preceding claims characterised in that the annular groove (6) in the lid (2) has a bottom which is narrower than the wall thickness of the edge (1a) of the body at the free end.

24. A container as set forth in one of the preceding claims characterised in that the connecting region (2b) of the lid enlarges conically from the groove region (2c) to the edge (2a) of the lid.