EP0690001B1 - Open-head metal drum - Google Patents

Description

The present invention relates to metal drums with full opening.

The invention relates more particularly to drums intended for the transport by containers of the maritime type of materials reputed to be dangerous.

One of the advantages of drums with full opening over drums with a crimped lid lies in their ease of cleaning and reconditioning and in the fact that all their components are easily reusable.

Known full-opening drums unfortunately have a disadvantage for transport, namely the large size that they present at the height of the clamp that holds their cover in place.

We know that the containers used to transport this type of barrel have extremely strict standardized dimensions. To be able to optimally use the interior space of these containers, the outside diameter of the drums with a capacity of between 200 and 250 liters must not exceed a diameter of 585 millimeters.

Such performance is possible in the case of barrels with crimped lids as described in document WO-A-85/0171.

In this document, the crimped edges of the barrels are folded inwards or else a diameter is narrowed at the height of the cover so as to limit the lateral dimensions of the standardized barrels. Such a solution is only applicable because of the reduced lateral extension of the crimped edge of the barrel covers.

Patent EP-A-0 509 978 in the name of the applicant, on which the preamble of claim 1 is based, describes a barrel with full opening in which the opening of the barrel is bordered by a spiral outward winding. The cover of this barrel is held in place by a clamping ring, the lower part of which is engaged in a peripheral groove.

Possibly reducing the amplitude of the winding of the edge of the barrel (typically from 11 to 14 mm) as described in EP-A-0 509 387 would not allow sufficient space savings to be able to equal the diameter of a barrel has crimped cover; in addition, the impact resistance of such a barrel is compromised, the volute winding playing a non-negligible role in the rigidity of the structure, and in maintaining the seal in the event of an impact, which would not be admissible in the case of transport of materials deemed dangerous.

In document DE-U-9313878.4, a barrel with total opening is described, the mouth of which is bordered by a scroll winding, provided with a cover and a clamping ring, in which the upper part of the side wall - which also has a standard diameter - has undergone a cone-shaped constriction, which makes it possible to reduce the diameter of the mouth of the barrel so that the diameter of the barrel once closed does not exceed the critical dimension of 585 millimeters.

It will be observed that a barrel with a tightened opening no longer offers 100% the characteristic of a "full opening" barrel where the diameter of the mouth corresponds strictly to that of the barrel, which can prove to be disadvantageous in particular in in the case of the transport of viscous materials or during reconditioning.

US-A-2,169,395 describes a method for the reconditioning of a barrel with a crimped edge. According to this method, before reconditioning, the upper wall set with the barrel is cut flush with the inner wall of the ferrule, leaving the bead due to the crimping, in which the peripheral part of the initial upper set wall is incorporated.

After repairing the barrel, a cover is placed over the bead bordering the barrel. This cover is held in place by a clamp embracing the edge of the cover and the remaining crimping. The lower edge of the clamp can be locked in a peripheral groove formed under said crimped edge.

The method described in US-A-2,169,395 does not apply to the manufacture of new drums. In addition, the size of the barrel thus reconditioned exceeds the maximum size tolerated for standardized barrels and therefore the problem of optimizing the dimensions of the barrels is not resolved as it is sought in the present invention. Furthermore, in the optional form where the edge of the clamping collar locks in a peripheral groove, it is difficult to guarantee optimal compression of the seal and, thereby, the sealing of the barrel in the event of extreme stresses ( shocks, etc.).

The object of the invention is to be able to market drums with full opening retaining the solidity qualities of a conventional barrel but having a reduced lateral size at the height of the lid.

Another object of the invention is that this barrel has no restriction in internal diameter at its mouth.

Another object of the invention is that these drums can be produced without having to use any particular tool requiring high investment.

• une virole en substance cylindrique constituant la paroi latérale du fût et se terminant à sa partie supérieure par un bord enroulé délimitant l'ouverture du fût. La virole comporte sur sa périphérie et sous ce bord enroulé une cannelure dont la partie concave est tournée vers l'extérieur de la virole;
• un couvercle en substance circulaire, apte à s'adapter sur le bord supérieur de la virole; ce couvercle présente le long de sa périphérie une gorge dont l'ouverture est tournée vers le bas et dans laquelle peut être engagé le bord supérieur de la virole; le flanc de ladite gorge le plus éloigné du centre du couvercle a la forme d'une couronne cylindrique dont le bord dirigé vers le bas constitue le bord extrême du couvercle, le fond de cette gorge est garni d'un joint d'étanchéité;
• un collier de serrage apte à assurer le maintien du couvercle sur la virole. Ce collier présente une section transversale en substance en forme de C, l'ouverture du C étant tournée vers le centre de l'anneau, ce collier comportant ainsi des bandes supérieure et inférieure qui correspondent respectivement aux branches supérieure et inférieure de la section en C et qui sont reliées entre elles par une bande médiane qui correspond à la partie médiane de la section en C. Ce collier de serrage, lorsqu'il est mis en place, s'appuye par sa bande supérieure sur le haut du couvercle, le long de la périphérie de celui-ci, tandis que la bande médiane encercle ladite couronne cylindrique du couvercle et que la bande inférieure est engagée par son bord libre dans ladite cannelure ménagée sous le bord enroulé du fût, le diamètre du bord libre du collier de serrage, lorsque ledit collier de serrage est serré en place, étant supérieur à celui du fond de la cannelure dans laquelle il est engagé.
• L'invention est caractérisée par le fait que le bord enroulé consiste en un ourlet plat formé par un double pli du bord de la virole rabattu sur lui-même contre la face externe de la virole.

The subject of the invention is a metal drum with full opening. This barrel has:

• a substantially cylindrical ferrule constituting the side wall of the barrel and ending at its upper part by a rolled edge delimiting the opening of the barrel. The ferrule has on its periphery and under this rolled edge a groove whose concave part is turned towards the outside of the ferrule;
• a substantially circular cover, adapted to fit on the upper edge of the shell; this cover has along its periphery a groove the opening of which faces downwards and in which can be engaged the upper edge of the ferrule; the side of said groove furthest from the center of the cover has the shape of a cylindrical crown whose edge directed downwards constitutes the extreme edge of the cover, the bottom of this groove is provided with a seal;
• a clamp suitable for maintaining the cover on the shell. This collar has a substantially C-shaped cross section, the opening of the C being turned towards the center of the ring, this collar thus comprising upper and lower bands which correspond respectively to the upper and lower branches of the C section. and which are connected to each other by a median strip which corresponds to the median part of the section in C. This clamping collar, when it is put in place, is supported by its upper band on the top of the cover, along from the periphery of the latter, while the central strip encircles said cylindrical crown of the cover and the lower strip is engaged by its free edge in said groove formed under the wound edge of the barrel, the diameter of the free edge of the clamp , when said clamp is tightened in place, being greater than that of the bottom of the groove in which it is engaged.
• The invention is characterized in that the rolled edge consists of a flat hem formed by a double fold of the edge of the ferrule folded back on itself against the external face of the ferrule.

Thanks to its design, the metal barrel in question does not exceed the standardized size of the barrel with cover set with equivalent capacity.

The hem has an internal fold adjacent to the side wall which ends with the free edge of the ferrule and an external fold, the height of the internal fold being advantageously between 0.5 and 0.75 times the height of the external fold.

In correspondence with the range of barrels concerned by the invention, the thickness of the side wall is generally between 0.8 and 1.5 mm.

The width of the cover groove is preferably between 4.5 and 6 times the thickness of the side wall of the barrel.

According to an advantageous embodiment, the outer crown of the cover has a height of between 0.5 and 1 times the height of the hem of the side wall.

In one embodiment, the lower band and the upper band of the collar are parallel to each other.

According to another embodiment, the upper band of the hose clamp forms a flat ring which extends in a plane perpendicular to the middle part of the collar, which has a cylindrical shape, the lower band of the collar joining at an obtuse angle. with this middle band.

The side of the peripheral groove located on the side of the center of the cover preferably has, over part of its height, the shape of a cylindrical crown.

According to an advantageous embodiment of the cover, the latter comprises a frustoconical zone connecting a central part to the inner flank of the peripheral groove of the cover.

The inner wall of the container is advantageously covered by a protective film in the form of a bag, the mouth of this bag being folded down between the edge of the side wall of the container and the outer crown of the cover.

A major advantage of the barrels according to the invention is that it makes it possible to store barrels with total opening in a standardized container while achieving a significant saving in space.

Another advantage of the barrel according to the invention is that it makes it possible to reuse, at the cost of a minor modification, containers with total opening currently in circulation on the market.

Another advantage of the barrel according to the invention is that the gain in diameter also affects the cover and the clamping ring, hence a significant gain in raw material.

Another advantage is that the present barrel respects the standard dimensions of a barrel with bungs with a crimped cover. By providing its cover with bungs (whose position is standardized), the present barrel can be used without modification of settings on an automatic filling line for barrels with bungs with crimped cover.

Other features and advantages of the barrel according to the invention will emerge from the description below of an advantageous embodiment, reference being made to the accompanying drawings.

Fig. 1 is a section along a vertical plane of the edge of a barrel according to the invention provided with its cover and its clamping ring.

Fig. 2 is a section through a barrel identical to that of FIG. 1 provided with a protective bag protecting the side wall from any contact with the material transported.

Fig. 3 is a schematic side view in section of a barrel according to the invention, the cover of which is provided with bungs.

The side wall 1 of the barrel is formed by a ferrule which has, in substance, a cylindrical shape; the free edge 2 of this ferrule is folded back on itself as a hem 3 against the outside face of the side wall 1.

It forms an internal fold 4 which adjoins the wall 1 and an external fold 5, both flattened against the side wall 1, so that the thickness of the hem bordering the side wall does not exceed the limit, three times l thickness of the side wall.

A peripheral groove 6 goes around the side wall 1, just below the hem 3.

The bottom 7 of this groove 6 is offset inwards relative to the cylindrical side wall 1.

The cover 8 is adopted by its peripheral part on the edge of the ferrule.

This cover 8 is bordered by a groove 9 opening downwards, at the bottom of which is placed a seal 10.

The outer side 11 of this groove has the shape of a cylindrical ring which extends parallel to the hem 3, so as to offer the smallest possible lateral extension, in accordance with the purpose assigned to the invention.

The cover 8 is held in place on the barrel by a clamp 12 in a split ring.

As can be seen in Figures 1 and 2, this collar 12 has a substantially C-shaped section, the opening of this section being directed towards the center of the ring.

This collar 12 is provided with clamping means for its installation, known elsewhere, which are not shown. These tightening means make it possible to hermetically seal the barrel once the collar is in place.

The upper part of the ring, which corresponds to the upper branch of the C-shaped section, forms an annular upper band 13 pressing on the periphery of the cover 12.

The middle part of the collar, corresponding to the stem of the C of the section, forms a band in a cylindrical crown 14 which is applied against the outer crown 11 cover 8.

The lower part of the collar 15, which corresponds to the lower branch of the section in C, is connected obliquely to the cylindrical crown 14, its end 16 being inserted in the peripheral groove 6 (without however coming up against the bottom of this peripheral groove 6).

The various elements forming the edge of the cover, the edge of the side wall and the clamping collar thus arranged form, under a reduced radial size, an assembly of remarkable rigidity allowing this barrel with total opening to meet the standards of resistance required for sea containers.

The internal fold 4 of the hem 3 has a length of between 0.5 and 0.75 times that of the external fold 5, which makes it possible both to absorb all the irregularities of the free edge 2 and to ensure rigidity sufficient at the edge of the container.

Despite the very small thickness of the hem 3, the seal 10 remarkably resists the cutting effects imposed on it when a shock is applied to the top of the barrel. This unexpected effect is due, among other things, to the fact that part of the stresses is taken up directly by the ferrule, via the clamp.

Note also the good seal obtained with respect to pressures likely to develop inside the barrel, despite a relatively small contact area between the hem 3 and the seal 10.

It is possible to limit the compression ratio of the joint between precise limit values due to the engagement of the end 16 of the lower band 15 of the clamp in the peripheral groove 6, the end 16 of the band lower does not abut against the bottom of the peripheral groove 6, therefore, the clamp has a slight vertical clearance which facilitates its installation and guarantees a controlled compression of the seal, regardless of slight dimensional variations of the various components.

It is also possible, according to a variant not shown, to use a clamp where the lower strip 15 is engaged perpendicular to the side wall 1 in the peripheral groove 6; the lower strip 15 is then parallel to the upper strip 13 of the clamp.

The sheet forming the groove 9 of the cover is subjected to a curvature of small radius, unusual for the thicknesses of sheets mentioned, which may make it necessary to shape the cover in two stages.

The seal 10 has, for equivalent performance, a reduced section compared to the seal of a conventional barrel.

A substantial saving is therefore made on the material of the joint.

Since the cover has a generally reduced diameter, a certain amount of metal is also gained during manufacture.

The hem 3 can be formed for example by prior execution of a volute winding like that which borders the drums with conventional total opening, then by crushing between two rollers of this winding; the peripheral groove, for its part, can be produced by completely standard tooling in the production or reconditioning lines.

It will be noted that it is therefore possible to easily repackage existing barrels in order to reconvert them into a compact barrel according to the invention.

The side 17 of the groove 9 located towards the center of the cover forms a cylindrical crown, parallel to the external side 11 of the cover 8, which contributes to strengthening the structure of the closure. This flank 17 is connected here to the central part 18 of the cover 8 by a frustoconical part 19 which facilitates the stacking of the covers 8.

Fig. 2 shows a particular use of the barrel with full opening according to the invention, which is also identical to that of FIG. 1.

To facilitate the cleaning and reconditioning of drums for the transport of materials deemed dangerous and to limit the risks of pollution, a practice which tends to develop at present is to place inside the barrel a protective film in the form of a bag or " liner". To avoid contact with the wall, this liner 20 is folded over the edge of the opening and wedged between the hem 3 and the seal 10.

In the case of barrels with restricted opening as described in the prior art, if the liner 20 has exactly the diameter of the interior wall, as the economy requires, there occurs, at the height of the opening, folds due to the extra length of the perimeter of the liner. These folds are detrimental to the good sealing of the barrel during transport.

Such a phenomenon cannot occur in the barrel according to the invention since the opening has exactly the same diameter as the whole of the shell. Any folds 26 can only occur at the level of the groove 6 where they are not likely to affect the seal.

Fig. 3 shows in schematic section a barrel according to the invention, the cover 21 of which is provided with bungs 22, 23. This barrel meets the standards for space requirement of a bung barrel with crimped cover; it can be used without changing the settings in filling lines for these barrels with crimped lids. This is not the case for barrels (as described in the prior art) whose upper part of the shell has a conical configuration.

In the present barrel, the location for the alignment of the bungs during filling can be carried out on a reference zone 24 situated on a cylindrical wall identical to that of a crimped barrel. The insertion of the bungs 22, 23 (whose spacing D is normalized) on the cover 21 is done without space problem since the diameter of this cover 21 corresponds to the diameter of the cylindrical side wall 1 and not to the restricted upper diameter d 'a barrel according to the prior art.

Claims (10)

1. Open-head metal drum, including

   - a substantially cylindrical shell constituting the sidewall (1) of the drum and terminating at its upper part in a rolled edge (3) delimiting the opening of the drum, and including, on its periphery, below this rolled edge (3), a hollow (6), the concave part of which points towards the outside of the shell;

   - a substantially circular lid (8) able to fit over the upper edge of the shell, the lid having, along its periphery, a groove (9), the opening of which points downwards and in which groove the upper edge of the shell can be engaged, the said groove flank (11) furthest from the centre of the lid (8) having the shape of a cylindrical hoop (11), the downwards pointing edge of which constitutes the far edge of the lid (8), the bottom of the said groove being lined with a seal;

   - a clamping collar in the form of a split ring (12) able to hold the lid (8) on the shell and having a substantially C-shaped transverse section, the opening of the C pointing towards the centre of the split ring (12), this clamping collar thus including upper and lower strips which correspond respectively to the upper branch (13) and to the lower branch (15) of the C-shaped section and which are connected to each other by a middle strip (14) which corresponds to the middle part of the C-shaped section, the clamping collar (12), when fitted, bearing via its upper strip (13) on the top of the lid (8) along the periphery thereof, while the middle strip (14) encircles the said cylindrical hoop (11) of the lid (8) and the lower strip (15) is engaged via its free edge (16) in the hollow (6) formed under the rolled edge (3) of the drum, the diameter of the free edge (16) of the clamping collar, when said clamping collar is clamped in place, being greater than the diameter of the bottom of the hollow (6) in which it is engaged;

   characterized in that

   - the rolled edge consists of a flat hem (3) formed of a double fold (4, 5) of the sidewall (1), folded over on itself against the external face of the shell.
2. Drum according to Claim 1, characterized in that the hem includes an internal folded portion (4) adjacent to the sidewall (1) terminating in the free edge (12) of the shell and an external folded portion (5), the height of the internal folded portion (4) being between 0.5 and 0.75 times the height of the external folded portion (5).
3. Drum according to Claim 2, characterized in that the thickness of the sidewall (1) is between 0.8 and 1.5 mm.
4. Drum according to either one of Claims 2 and 3, characterized in that the width of the groove (9) of the lid (8) is between 4.5 and 6 times the thickness of the sidewall (1) of the drum.
5. Drum according to any one of the preceding claims, characterized in that the external hoop (11) of the lid has a height of between 0.5 and 1 times the height of the hem (3) of the sidewall (1).
6. Drum according to any one of the preceding claims, characterized in that the lower strip (15) and the upper strip (13) of the collar (12) are mutually parallel.
7. Drum according to any one of Claims 1 to 5, characterized in that the upper strip (13) of the clamping collar (12) forms a flat ring stretching perpendicular to the middle strip (14) of this collar (12), which middle strip takes on a cylindrical shape, the lower strip (15) of the collar (12) connecting to this middle strip (14) at an obtuse angle.
8. Drum according to any one of the preceding claims, characterized in that the groove flank situated on the lid side has the shape of a cylindrical hoop, at least over part of its height.
9. Drum according to any one of the preceding claims, characterized in that the lid includes a central part connected by a frustoconical region to the inner flank of the peripheral groove in the lid.
10. Drum according to any one of the preceding claims, characterized in that the interior wall of the vessel is covered by a protective film (20) in the form of a bag, the mouth of this bag (20) being folded over between the edge of the sidewall (1) of the vessel and the external hoop (11) of the lid (8).

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