EP2576369A1

EP2576369A1 - Packaging

Info

Publication number: EP2576369A1
Application number: EP11744058.6A
Authority: EP
Inventors: Bram Jasper Vannieuwenhuyze
Original assignee: Ibens Joke Maria Jozef
Current assignee: Ibens Joke Maria Jozef
Priority date: 2010-06-07
Filing date: 2011-06-07
Publication date: 2013-04-10
Also published as: BE1019365A5; WO2011154800A1

Abstract

The invention relates to a packaging (1, 1') consisting of a lid (2), a side wall (3), which merges into an upright lid edge (5), a bottom (4) with a base rib (6) which adjoins the side wall (3) in such a way that when the first packaging (1) is stacked on top of a second packaging (1'), the lid edge (5) of the second packaging (1') rests on the bottom (4) of the first packaging (1) inside said base rib (6), with a gain in volume for the same tin height inside the packaging (1), without the bottom (4) having to be weakened for this purpose, due to the bottom (4) comprising a concave central part (11) and due to the base rib (6) being of convex design in the direction of the side wall (3) and having a radius R adjoining this side wall (3) at an angle (a).

Description

Packaging

The invention relates to a packaging, comprising:

a lid;

- a side wall which merges into an upright lid edge;

a bottom which comprises a base rib, said base rib adjoining the side wall; in such a way that when said first packaging is stacked on top of a similar second packaging, the lid edge of the second packaging rests on the bottom of the first packaging, inside said base rib.

Preferably, this packaging is a metal packaging, such as for example a beverage tin or beverage can or a food tin or food can, etc. The invention can be used for a wide range of packagings in the beverage industry, food industry and general packaging industries.

A typical known beverage tin (beverage can) essentially consists of an open tin with a lid on top. The lid comprises a pull lip. The open tin furthermore consists of a bottom and a side wall. The bottom typically has a narrowing or constriction from the outer diameter of the packaging towards a base rib. Inside the base rib, the bottom is usually of a concave design. The top of the side wall is usually necked at the top. After closing the lid (by seaming) on the open tin, the lid has an upright lid edge having a diameter which has to fit around the outer circumference of the base rib of the bottom. The industry requires a tin or can to be stackable. The present known standard method for stacking beverage tins or other similar metal packagings, such as for example food cans, is based on the outer circumference of the base rib resting on the upright lid edge of a beverage tin situated underneath. The bottom is in this case provided with a narrowing or constriction from the outer diameter of the packaging towards the base rib, the periphery of which is smaller in diameter than the lid edge. This base rib also serves as a support surface for the beverage tin when this is placed on a flat surface. The base rib is formed during the forming process of the tin. The lid edge is essentially the result of the closing operation (seaming operation) which is carried out at the filler. A drawback of the existing beverage tin design is that volume is lost in the tin due to the stacking corner (the narrowing or constriction towards the base rib) and deep bottom (concave central part inside the base rib), as a result of which the tin has to be made taller or the diameter has to be increased. This prevents further reductions in the weight of the packaging. Another drawback is the fact that the diameter of the lid cannot be reduced any more. The angles which would have to be used in order to achieve this would then become too large. In addition, the stacking corner is very disadvantageous with regard to the consumption of material, as this zone is at least as thick as the thickness of the starting material. JP2002284167A describes a tin, the top side of which has a diameter which is smaller than the outer diameter of the tin, and the bottom side of which is provided with a central recess which delimits a base rib, so that the base rib fits completely across the top side of the tin. The inward shape of the bottom side has a deep sharp outer edge. It is a drawback here that this sharp outer edge and the flat bottom offer little strength. In addition, this concept reduces the volume of the tin and requires a greater tin height for the same volume. The steep incline on the inside causes problems in the case of a paint-spraying operation due to its inaccessibility.

EP 0874760 Bl describes a stack of at least two tins which are locked one inside the other by means of a resilient closure. The tin has an outer edge which projects at the bottom and resiliently fits around the top edge of another tin. The stack can be lifted in its entirety without any tins becoming dislodged. However, the projecting resilient bottom edge is very susceptible to deformation and has to extend as far as below the lid edge in order to click into place. In addition, the bottom edge is not easy to produce, it is expensive and therefore no gain in volume or saving in material is achieved. Attempts have already been made to increase the volume of such a tin at the same tin height. Such tins have been described, for example, in GB 1 572 031 and in DE 10 2006 005 064. To this end, the bottom of each of these tins is of flexible design. However, with such a flexible bottom, such tins are too weak to be used as packaging for, for example, carbonated beverages. Such a type of bottom does not meet strength requirements such as fold-out pressure, bottom growth and drop test.

It is therefore an object of the invention to provide a packaging where no volume is lost, and volume may even be gained, at the same tin height inside the packaging, without the bottom having to be weakened for this purpose (as was the case with GB 1 572 031 and DE 10 2006 005 064).

This object of the invention is achieved by providing a packaging, comprising a lid, a side wall, merging into an upright lid edge, a bottom which comprises a base rib, said base rib adjoining the side wall, in such a way that when said first packaging is stacked onto a similar second packaging, the lid edge of the second packaging rests on the bottom of the first packaging, inside said base rib, with the bottom, viewed from the outside of the packaging, comprising a central part which is of concave design, and said base rib being of convex design in the direction of the side wall and having a radius, said radius adjoining said side wall at an angle.

Due to the bottom according to the invention being designed to have a concave central part and to a base rib which is convex on the side facing the side wall, the bottom and the lid in addition being designed in such a manner that, upon being stacked, the lid edge of the one packaging rests on the bottom of the other packaging, inside the base rib, it is possible to increase the volume inside a tin at the same tin height without having to weaken the bottom for this purpose. On the contrary, the bottom can thereby even be reinforced compared to the present standard packagings. Packagings with such a reinforced bottom are particularly suitable for packaging, for example, products which have been pasteurized or sterilized during the filling processes, or products which are pressurized internally when they are on the shelves or in the market, etc.

Due to the reinforced bottom, it is moreover possible to make this bottom thinner while retaining the same strength or to lower the point of ironing of the side wall with respect to the bottom compared to the known packagings. In this way, a significant weight saving of the packaging can be achieved.

Due to the manner of stacking, in which the lid edge of the one packaging rests on the bottom of the other packaging, the lid diameter can be made smaller than with current standard packagings. This results in significant cost savings, as the lid constitutes a large part of the total cost.

In addition, it is possible to produce such a packaging according to the invention in such a manner that the most drastic permanent deformations are carried out on the inner side of the circumference defined by the side wall and the base, without these having an impact on the outer circumference of the tin. Thus, the pressure (for example due to variations in temperature) on the packaging is reduced. A preferred embodiment of a packaging according to the present invention is of substantially cylindrical design, with the side wall being configured as a cylinder wall, with the base rib adjoining the side wall at a height H and with the angle at which the radius adjoins the side wall being smaller than or equal to arctan ((the outer diameter of the side wall/2 - the outer diameter of the lid edge/2)/H).

With such an embodiment, said height H is preferably smaller than or equal to the height of the upright lid edge (also referred to as the shoulder depth, this being the distance from the uppermost point of the lid edge to the lid) increased by ((the outer diameter of the side wall/2 - the outer diameter of the lid edge/2)/tan(30)). Even more preferably, said height H is less than 1 1 mm and most preferably, said height is between 1 and 3 mm. H can be kept as small as possible by keeping both the radius R and the angle at which the radius adjoins the side wall as small as possible.

Furthermore, this radius R is preferably also greater than or equal to 0.5 mm.

In a particular, simple embodiment of a packaging according to the present invention, the central part of the bottom adjoins said base rib.

In other embodiments of a packaging according to the present invention, the bottom comprises at least one groove which is disposed inside said base rib, in which, when said first packaging is stacked onto a similar second packaging, the lid edge of the second packaging rests on the at least one groove of the first packaging.

The term groove is understood as meaning a narrow recess or indentation on the bottom of a packaging, for example a beverage can. The groove may be continuous or discontinuous. The groove preferably follows the shape of the bottom. Less preferably, the groove may (if this results in an advantage, for example, with regard to strength) also have a different shape than the bottom, for example a polygonal groove in a circular bottom or a circular groove for a square bottom etc. In a particular embodiment, the groove is defined or formed by two ribs, protuberances or radii. In another embodiment, a groove is formed, or it is given the function of a groove with sufficient support inside the groove, by a single rib or protuberance, preferably having a rounded shape.

The shape of the groove preferably matches the shape of the lid edge of the stacked can situated underneath as closely as possible. Thus, for example, a cylindrical can will preferably have a circular lid edge to rest on a circular groove. Other shapes of lids and grooves are, for example, square, rectangular, polygonal or oval. The groove (grooves) and/or the rib (ribs) of a packaging according to the present invention preferably has/have a rounded shape, in view of the optimum strength and simple construction of this shape, but other shapes are also conceivable. The groove may, for example, be rounded or V-shaped or have any other shape which is suitable to receive a lid edge. In order to be able to make this (these) groove (grooves) and/or this (these) rib (ribs) still stronger, these can also be segmented into segments which adjoin one another in each case at an angle. In terms of production engineering, it suffices, for example, to give the die by means of which the bottom is formed a corresponding shape. Within the same groove, each segment can therefore be at a different angle to the ribs, in which case this angle can also be negative. These segments can be designed so as to be inwardly or outwardly displaceable (in the direction of the axis of the tin), so that each segment can assume different angles. A cross section of the groove can thus assume all shapes and may be different within the same groove. This may, for example, also be of polygonal design, even if the lid edge which is to engage therewith is, for example, of arcuate design.

The lid edge can preferably be received freely by the groove, without additional forces having to be exerted on the lid edge, i.e. without clamping. The groove preferably exerts no other force on the lid edge than the force of gravity.

The ribs of a packaging according to the present invention are preferably designed in such a manner that they can hold a volume, such as beverage or food, in the tin. In other words, the ribs are preferably not separated from the contents of the tin. In a preferred embodiment of the packaging of the invention, the groove is delimited by at least one rib. This at least one rib may, for example, be the base rib of the packaging. More specifically, the groove may be delimited by two ribs.

In a particular embodiment, the lid edge rests on the side of the groove. In another embodiment, the lid edge rests on the centre of the groove. The invention thus relates to a packaging in which a lid edge of a second packaging can be placed within the base rib of a first packaging. In this case, the first and the second packaging may be identical. The first and the second packaging may also be different.

In a particular embodiment, the lid diameter of the packaging or of the packaging onto which it is stacked, may be smaller than or equal to the standard lid diameter of known packagings. The side wall of the packaging preferably has a top with a neck or constriction from the outer diameter of the packaging towards the lid edge, so that the upright lid edge falls inside the diameter of the side wall. The lid edge of a second packaging then has a diameter which is smaller than the bottom edge (base rib) of a first packaging. In a particular embodiment, at least one of the ribs comprises one or more indentations. Such indentations can be used to further reinforce ribs. These indentations are preferably of concave design (preferably having a radius rl). More specifically, the base rib can comprise one or more of said indentations. Thus, this base rib can be designed sufficiently wide while retaining strength in order to produce an inner diameter of said base rib which corresponds to the diameter of a lid edge which is of a much more narrow design than the known lid edges. Such indentations can have any conceivable shape (also including a groove shape), as long as the base rib rests on both sides of such indentations, when the packaging is placed on a flat surface.

A specific embodiment is the one where the packaging is cylindrical and the lid edge and the base rib are circular.

In a particular embodiment, the lid and the side wall are seamed via the upright lid edge. The bottom and the side wall may be integrally formed in one piece. In another embodiment, the packaging has a separate bottom, which is for example seamed onto the side wall.

In particular embodiments, the lid may comprise a pull lip or re-usable closure. With such embodiments, the parameters of the bottom profile, such as the depth of grooves, radii, etc. are preferably chosen such that, when stacked, the bottom of the first packaging and the pull lip or re-usable closure of the second packaging do not quite touch one another. In a particular embodiment, the packaging according to the invention is a beverage can or food can. The packaging is preferably made of metal, such as for example steel or aluminium, or of plastic.

In a particular embodiment of a packaging according to the present invention, the bottom comprises two or more grooves of different diameters for receiving a lid edge of one of these diameters. The bottom of the packaging can furthermore comprise one or more reinforced grooves which partly contribute to the strength of the bottom. The grooves may have the same or different depths and/or widths. In a particularly preferred embodiment, the bottom is reinforced by the edge of at least one said rib which is turned towards the central part, is essentially positioned at a negative angle with respect to the central part (this may be achieved, for example, by pushing the rib, after it has been formed, using a force on the bottom side of the rib, to the outside of the can, so that the top of the rib (which is situated furthest from the rest of the packaging) is directed to the inside of the bottom). In such a specific embodiment, the central part of the bottom is delimited by said rib, with the edge of this rib which is turned towards the central part being essentially positioned at a negative angle with respect to the central part. Preferably, the edge of the base rib of a packaging according to the present invention which is turned towards the central part is essentially positioned at a negative angle with respect to the central part. By exerting a force on the inside of the sphere on the rib with a specific profile, it is also possible to produce ribs having various kinds of possible alternative shapes.

The bottom of a packaging according to the present invention can furthermore also be reinforced by means of an additional deformation of at least one of the grooves.

In a particularly preferred embodiment of a packaging according to the present invention, the angle at which the radius of the base rib adjoins the side wall is preferably equal to 0 degrees.

In a highly preferred embodiment of a packaging according to the present invention, the inner side of the base rib, viewed on the inside of the packaging, is of a concave design in the direction of the side wall and has a radius R', this radius R' adjoining the inner side of the side wall at an angle.

More specifically, such a packaging can be made from sheet material having a blank thickness, in which the side wall comprises a zone having a minimum wall thickness which is smaller than the blank thickness, in which said zone starts at a height h and in which the angle at which the radius R' adjoins the inner side of the side wall on the inside of the base rib is smaller than or equal to arctan ((blank thickness - minimum wall thickness)/(h - R)).

Ironing of the side wall preferably starts at height H. At an angle at which the radius adjoins the side wall on the outer side of the base rib and which is equal to 0, this height H is preferably equal to R. The height (h-R) (h being the start of the minimum wall thickness) then forms a reinforcement zone. When the latter angle is greater than 0, then the effect of the reduction in weight of the bottom will become increasingly smaller as H increases. Said height H is therefore also preferably smaller than or equal to the height of the upright lid edge (also referred to as the shoulder depth, which is the distance from the uppermost point of the lid edge to the lid) increased by ((the outer diameter of the side wall/2 - the outer diameter of the lid edge/2)/tan(30)).

With such a substantially cylindrical packaging, in which the side wall is configured as a cylinder wall, said radius R' on the inner side of the base rib is preferably smaller than or equal to (the outer diameter of the side wall - the outer diameter of the lid edge)/4.

The diameter of the central part of the bottom of a packaging according to the present invention is preferably smaller than the inner diameter of the lid edge.

According to the present invention, the stacking principle is changed in such a way that the lid edge of a packaging is placed inside the base rib of a packaging placed above it. It is also possible to develop a way of stacking lid edges of different diameters. This makes it possible to stack both relatively large and relatively small tins on top of one another. Depending on the strength requirements of the bottom, all parameters of the bottom profile can easily be changed by changing inter alia radii, linear parts, angles and depth of the grooves. In principle, a cross section can assume many shapes and can even differ within the same groove.

Where existing beverage tins have an outwardly ribbed or constricted bottom, in which case a critical outer edge fits inside the lid edge of another beverage tin, a beverage tin according to the present invention provides a base rib which is preferably in line with the side wall of the beverage tin or has a steep angle where it adjoins the side wall. When the base rib adjoins the side wall without an angle, it is possible to achieve maximum filling of the tin with minimal dimensions. Furthermore, the base rib serves as a support surface when the packaging is placed on a flat surface. By using the diameter of the bottom edge to a maximum degree, the bottom volume is increased, as a result of which, the height of the finished tin can be smaller for the same tin volume and lid diameter. It also leads to a larger support surface of the packaging and to improved distribution of the volume across the bottom, as a result of which the packaging can stand on a support surface in a more stable way, as the centre of gravity is situated lower.

The stronger bottom with grooves/ribs makes it possible to make the concave central part of the bottom (bottom sphere) flatter (less deep) or provide it with shorter ribs than is the case with the standard packagings having such a concave central part. The bottom sphere can be made even flatter by pushing the rib which adjoins this bottom sphere using a force on the bottom side of the rib (where it adjoins the bottom sphere) to the outside of the tin, so that the top of the rib is directed towards the spherical shape. With virtually cylindrical embodiments, it is additionally possible to greatly reduce the diameter of the central concave part, thus increasing the resistance of the bottom to folding out under high pressure.

Irrespective of the stackability, the packaging of the present invention provides a reinforced bottom and, if desired, a smaller lid diameter. The central concave part and the grooves/ribs reinforce the bottom. The lid diameter can now be made smaller, as axial forces which occur when the top of the packaging is being necked are more readily absorbed by a wider base. In addition, the loss of volume resulting from a longer constricted neck is compensated for by the gain in bottom volume. This means that the lid diameter can be made smaller for the same tin volume, resulting in an enormous cost saving. The tin height can be significantly reduced for the same tin volume and lid diameter. This immediately results in a more compact stack. The lid edge and groove fit inside one another in such a way that the height/distance between the lid and the bottom is minimal. There is therefore only minimal loss of unused volume in the stack. The stackable packaging of the present invention thus has several advantages, as is explained below in more detail: • It is possible to save on the costs of metal because parts can be made thinner without loss of strength and because the height can be reduced for the same volume. Thus, the weight of the packaging (tin and/or lid) can also be reduced. The costs of transportation, storage and other packaging costs, such as inter alia plastic films, fall due to a more efficient method of stacking which is a direct result of the design of the packaging (e.g. due to the lower height, an additional layer can be added to a pallet). All this can be carried out while satisfying the strength requirements, including resistance to internal pressure and dynamic forces resulting from shocks and temperature variations. The estimated gain in material for a 33 cl beverage tin could be 12-15 %.

• The manufacturing process can be simplified. Due to the lack of a long, necked stacking corner, less wrinkling, if any, will occur during deep- drawing and shaping of the bottom.

• As a result of the invention, it is possible to use stronger materials having better mechanical properties, inter alia yield point and tensile strength, for the packagings while further reducing the packaging thickness and weight. The present stacking corner caused wrinkling and thickening when using such stronger materials. In order to limit this phenomenon as much as possible, the angle at which the radius adjoins the side wall is preferably as small as possible and most preferably 0.

• The material on the side wall can be made thinner (the point of ironing can be lowered) as this tin has a greater wall length than the existing standard packagings due to the constriction or cone angle of the bottom being omitted. This results in a more efficient use of the material which is available for thinning. The possible gain in the thinning volume is approximately 8 mm (for a beverage can having a volume of 33 cl and a diameter of 66 mm) expressed in height, depending on the tools used for thinning. An additional advantage is the fact that the thickening in the stacking corner can be omitted. Thus, the invention leads to a significant weight loss of the bottom, as a result of which the total weight of the packaging/tin is also significantly reduced.

• Due to the absence of the stacking corner (constriction of the bottom or cone), necking the tin at the top can be carried out much more forcefully, as this necking operation is accompanied by large axial forces acting on the stacking corner. These forces lead to a deformation of the stacking corner. In the design of the present invention, there is room to shorten the neck at the top of the tin by, for example, making it slightly steeper. This frees up additional volume in the tin and makes it possible to adjust the height of the tin for the same product further down. The idea results in less waste or fewer rejects due to wrinkling in the constricted zone of the top of the tin and also results in a stable geometry of the tin. The thinned section can be increased by approximately 8 mm (for a beverage can having a volume of 33 cl and a diameter of 66 mm) compared to the standard design and this can be done due to the omission of the stacking corner and the geometry of the radius R with the angle alpha of the base rib.

• The present invention makes it possible to increase the speed of the production lines. The outer diameter of the bottom is larger than that of standard tins, as a result of which the conveying of the tins in production lines of both the filling company and the tin manufacturers runs more smoothly. It also reduces the risk of toppling over, partly because the centre of gravity is lower. Also, the tins of the present invention can be conveyed more quickly if use is made of conveying devices using air as the means of transportation. Installations using air can utilize the grooves in the bottom of a packaging which comprises a plurality of grooves. • The present invention fulfils the consumer requirements better and ensures the integrity of the tin. Filled tins are often under pressure due to carbonization (C0₂) or being filled with nitrogen. By applying the present invention, it is possible to respond better to deformation caused by temperature variations. The bottom can be made to bend in a controlled manner by taking into account the depth, radii, angles and shape of the grooves and protuberances or ribs. If the bottom does not allow for any deformation, every variation in pressure acts on the lid, as a result of which this will start to bulge. This prevents the use of thinner lids.

• The present invention makes maximum use of the dimensions of a cylinder. The more efficient use of the cylinder together with the new bottom design makes an immediate reduction in the finished tin height possible. The reduction in the tin height may be approximately 3 mm and possibly more if a shorter constriction is provided.

• The present invention makes it possible to use smaller lid diameters by providing the bottom with adapted grooves in which a corresponding lid edge can be accommodated. This makes it possible to achieve a saving in the costs of metal of the lid. With the present stacking principle, the stacking corner would have to be increased and made longer in this case, which is disadvantageous with regard to the consumption of material and regarding collapse of the stacking corner when constricting the top (neck). · Smaller lid thicknesses are possible as the bottom can move in a controlled way, the latter remaining within the base. If the bottom is made too strong and cannot deform in such a controlled manner (as is actually the case according to the invention), then all pressure variations caused by temperature or shocks act on the lid, resulting in a bulge being formed on the lid (bulging of the lid). Due to the fact that a bottom according to the invention can actually move in a controlled manner, bulging of the lid is prevented. A packaging according to the present invention can be used for packaging beverages, foodstuffs or other substances, such as paints, chemicals or aerosol products, etc. The invention will now be explained in more detail by means of the following detailed description of some preferred embodiments of a stackable packaging according to the invention. This description is only intended to provide illustrative examples and to indicate further advantages and features of these packagings, and can therefore not be interpreted as a limitation of the area of application of the invention or of the patent rights defined in the claims.

In this detailed description, reference numerals are used to refer to the attached figures, in which: - Fig. 1 shows a stack comprising a first and a second beverage can according to the prior art in perspective;

- Fig. 2 shows a stack comprising a first and a second beverage can according to a first embodiment according to the invention in perspective;

- Fig. 3 shows the stack from Fig. 1 in front view; - Fig. 4 shows the stack from Fig. 3 in front view;

- Fig. 5 shows the stack from Fig. 1 in detail at the location of the bottom of the first beverage can and the lid of the second beverage can, with the left half of the stack being shown in front view and the right half being shown diagrammatically in cross section; - Fig. 6 shows the stack from Fig. 2 in detail at the location of the bottom of the first beverage can and the lid of the second beverage can, with the left half of the stack being shown in front view and the right half being shown diagrammatically in cross section; Fig. 7 diagrammatically shows a beverage can from Fig. 1 in cross section at the location of its bottom;

Fig. 8 shows a part of a beverage can from Fig. 1 , which is designated A in Fig. 7, in more detail;

Fig. 9 diagrammatically shows a beverage can from Fig. 2 in cross section at the location of its bottom;

Fig. 10 shows a part of a beverage can from Fig. 2, which is designated B in Fig. 9, in more detail;

Fig. 1 1 diagrammatically shows the connection of a base rib to the side wall in an embodiment such as the beverage can from Fig. 2 in more detail,

Fig. 12 diagrammatically shows a second embodiment of a beverage can according to the present invention in cross section at the location of the right- hand side of its bottom;

Fig. 13 shows a part of the beverage can from Fig. 12, which is designated C in Fig. 12, in more detail;

Fig. 14 diagrammatically shows different variants of the first embodiment of a beverage can according to the present invention, with different radii by which the base rib adjoins the side wall, in cross section at the location of the right-hand side of their bottom;

Fig. 15 diagrammatically shows a second stack of a first beverage can and a second beverage can according to a third embodiment according to the present invention in cross section at the location of the bottom of the first beverage can and the lid of the second beverage can, in the non-stacked state;

Fig. 16 diagrammatically shows a third stack of a first beverage can and a second beverage can according to a fourth embodiment according to the present invention in cross section at the location of the bottom of the first beverage can and the lid of the second beverage can, in the non-stacked state;

Fig. 17 diagrammatically shows a fifth embodiment of a beverage can according to the present invention in cross section at the location of the right- hand side of its bottom;

- Fig. 18 diagrammatically shows by means of a diagrammatic cross section at the location of the right-hand side of the bottom of different beverage cans, how the volume in the base rib can be increased by means of indentations without loss of strength of the base rib; - Fig. 19 diagrammatically shows by means of a diagrammatic cross section of a stack of a first and a second beverage can according to the present invention, at the location of the right-hand side of the bottom of the first beverage can and the right-hand side of the lid of the second beverage can, how the lid edge of the second beverage can can rest on the left-hand side of a groove in the bottom of the first beverage can;

Fig. 20 diagrammatically shows by means of a diagrammatic cross section of a stack of a first and a second beverage can according to the present invention, at the location of the right-hand side of the bottom of the first beverage can and the right-hand side of the lid of the second beverage can, how the lid edge of the second beverage can can rest on the right-hand side of a groove in the bottom of the first beverage can;

Fig. 21 diagrammatically shows by means of a diagrammatic cross section of the right-hand side of the bottom of a beverage can according to the invention in a first formed state and in a second reformed state, how the bottom of a beverage can can be reinforced by means of reforming a rib;

Fig. 22 shows a sixth embodiment of a beverage can according to the present invention with a reformed rib in partial cross-sectional perspective at the location of the bottom thereof; - Fig. 23 diagrammatically shows the beverage can from Fig. 22 in cross section at the location of the bottom;

Fig. 24 shows a seventh embodiment of a beverage can according to the present invention with a reformed rib in partial cross-sectional perspective at the location of the bottom thereof;

- Fig. 25 diagrammatically shows the beverage can from Fig. 24 in cross section at the location of the bottom;

- Fig. 26 shows an eighth embodiment of a beverage can according to the present invention with a reformed rib in partial cross-sectional perspective at the location of the bottom thereof;

Fig. 27 diagrammatically shows the beverage can from Fig. 26 in cross section at the location of the bottom;

- Fig. 28 diagrammatically shows the beverage can from Fig. 22 in cross section at the location of the right-hand side of the bottom; - Fig. 29 diagrammatically shows the beverage can from Fig. 22 with a first and a second formed rib as ninth embodiment in cross section at the location of the right-hand side of the bottom;

Fig. 30 diagrammatically shows the beverage can from Fig. 22 with a first and a second formed rib and with a formed base rib as tenth embodiment in cross section at the location of the right-hand side of the bottom;

- Fig. 31 diagrammatically shows a stack of a first and a second beverage can according to an eleventh embodiment according to the invention in cross section at the location of the right-hand side of the bottom of the first beverage can and the right-hand side of the lid of the second beverage can. Both the beverage cans (1 , Γ) according to the invention, as illustrated in Figs. 2, 3, 6, 9-31 , and the beverage cans (1, Γ) according to the prior art, as illustrated in the Figs. 1 , 3, 5, 7-8, are of a substantially cylindrical design and in each case comprise a lid (2), a side wall (3) and a bottom (4). The side wall (3) in each case ends in a continuous circular upright lid edge (5). The bottom (4) in each case comprises a continuous circular base rib (6), by means of which these cans (1 , ) are supported when they are placed on a flat surface. Furthermore, the bottom (4) in each case also comprises a concave circular central part (1 1).

The bottom (4) of the standard beverage can (1 , 1 ') as illustrated in Figs. 1 , 3, 5, 7-8 is constricted in the direction of the side wall (4), in such a manner that the base rib (6) of a first beverage can (1) fits inside the lid edge (5) of a second beverage can (1 ') when this first beverage can (1) is stacked onto the second beverage can (1 '), as can clearly be seen in Fig. 5.

With the illustrated beverage cans (1, Γ) according to the invention, the base rib (6), viewed on the outer side of the beverage can (1, ), is in each case convexly configured in the direction of the side wall (3), with a radius R which adjoins the side wall (3) at an angle (a). The lid edge (5) of such a second can ( ) can rest on the bottom (4) of the first packaging (1), inside said base rib (6), when such a first can (1) is stacked onto this second can (Γ).

In the embodiments as illustrated in Figs. 2, 4, 6, 9-17, 19-30, the cans (1 , ) to this end in each case comprise one or more continuous circular grooves (7, 8) which are arranged inside said base rib (6) and in which the lid edge (5) of a second can (1 , 1 ') can rest. The grooves (7, 8) are in each case delimited by continuous circular ribs (6, 9)·

In the embodiments such as illustrated in the Figs. 18 and 31, the base rib (6) directly adjoins the concave central part (1 1) of the bottom (4), so that the lid edge (5) of a second can (1 , 1 ') here when stacked rests inside the base rib (6) against this base rib (6) or against the concave central part (1 1) of the bottom (4).

In Figs. 1 to 10, a comparison is made between a known standard beverage can (1, ) having a volume of 33 cl and a first embodiment of a beverage can (1 , ) according to the invention which likewise has a volume of 33 cl and satisfies at least the same strength requirements.

The first embodiment of a beverage can (1 , ) according to the invention comprises a first continuous circular groove (7) which, on its outer side, is delimited by the base rib (6) and, on its inner side, by a second rib (9). This first groove (7) is configured in such a way that the base rib (6) of a second beverage can (1 ') can engage with it, as can clearly be seen in Fig. 6. The bottom (4) of such a beverage can (1, 1 ') according to the first embodiment furthermore comprises a second continuous circular groove (8) with a smaller diameter than the first groove (7), the second groove (8) being delimited by the second rib (9) on its outer side and by a third rib (9) on its inner side. This third rib (9) adjoins the concave central part (1 1) of the bottom (4). The purpose of the second groove (8) is to receive a lid edge (5) of a smaller diameter and/or to reinforce the bottom (4).

As can clearly be seen in comparative Figs. 5 and 6, it is possible, when a beverage can (1 , ) according to the invention is produced which satisfies at least the same strength requirements, to make the bottom (4) significantly less deep than the bottom (4) of a standard beverage can (1, ), so that beverage cans (1, Γ) stacked on top of one another can border one another much more closely and the pull lip (12) on the lid (2) of the bottom beverage can ( ) does not quite touch the bottom (4) of the top beverage can (1). As can clearly be seen in the comparative Figs. 3 and 4, which illustrate the stacking of the beverage cans (1, Γ) according to the prior art and according to the first embodiment according to the invention (1, ) on a similar base, it is possible to fit the same volume into a tin of the same diameter having a significantly lower height. The difference in stack height of two beverage cans (1, 1 ') is approximately 5.6 mm. This does not include the shortening of the neck at the top. The more compact stack height is due to the omission of the constriction at the bottom (4) next to the base rib (6) and the positioning of the lid edge (5) of the bottom beverage can ( ) inside the base rib (6) instead of outside the base rib (6). Moreover, due to this restriction of the tin height, less material is required to produce a beverage can (1 , 1 ') containing the same volume. In addition, a further saving on material can be achieved with a beverage can (1 , Γ) according to the invention, as is clearly illustrated in comparative Figs. 7 to 1 1 , by inter alia lowering the point where ironing of the side wall (3) starts. This is possible because the bottom (4) no longer comprises a constriction as is the case in the prior art, but the base rib (6) instead directly adjoins the side wall (3) with a radius R and because the bottom (4) is sufficiently reinforced by means of the ribs (6, 8) and the grooves (7, 9). At the location of the base rib (6), the wall thickness is equal to the blank thickness (TO) from which the beverage can (1, Γ) is made. As a result thereof, the height (H) of the point from which the metal having the thickness of the bottom (4) of the beverage cans (1 , Γ) is ironed and gradually constricted in the shape of a cone having an angle (γ) to form the minimum wall thickness (d) of the side wall (3) can be lowered significantly. With standard beverage cans (1 , Γ), this height (H) is approximately 1 1 mm, while with the illustrated beverage can, this is barely 3 mm. This height (H) can even be less. Preferably, this height (H) is less than or equal to the height (s) of the upright lid edge (5) increased by ((the outer diameter of the side wall (3)/2 - the outer diameter of the lid edge (5)/2)/tan(30)). The zone in which the side wall (3) of the beverage can (1 , ) has the minimum wall thickness (d) starts at a height h. The angle (γ) is preferably smaller than or equal to arctan ((blank thickness (TO) - minimum wall thickness (d))/(h-R)). Viewed on the inner side of the beverage can (1, 1 '), the inside of the base rib (6) is of concave design in the direction of the inside of the side wall (3), with a radius (R'), this radius (R') adjoining said inside of the side wall (3) at said angle (γ). This radius (R') is preferably smaller than or equal to (the outer diameter of the side wall (3) - the outer diameter of the lid edge (5))/4. The weight of the bottom (4) of a beverage can according to the invention is therefore less than the bottom (4) of any beverage can according to the prior art and this applies to any size.

The manufacturing process of aluminium and steel tins comprises deep-drawing and ironing the side wall (3), starting with a circular plate of, for example, EN AW-3104 (AlMgl Mnl ) alloy or DWI steel type having a maximum blank thickness of 0.3 mm, after which the tin is filled and provided with a lid (2). First, a shallow tin is drawn, which is then redrawn more deeply and subsequently the side wall (3) is ironed. Due to the saving in material achieved according to the invention, it is now possible to produce a can (1 , 1 ') either from a blank having a smaller blank thickness or to start with a smaller circular plate having the same blank thickness, as significantly less material is required to form the bottom.

The latter option makes it possible to produce more tins per stroke from the same width or to use the width to its maximum. The production efficiency thus increases, both with regard to the number of production units and with regard to material utilization.

Instead of directly adjoining the side wall (3) with a radius R, the base rib (6) of a beverage can (1, Γ) according to the invention can also adjoin the side wall (3) with the radius R at an angle (a), as is illustrated in the second embodiment of a beverage can (1) according to the invention in Figs. 12 and 13. Apart from that, the illustrated second embodiment (1) is analogous to the first embodiment of a beverage can (1 , 1 ') according to the invention. The angle (a) is preferably smaller than arctg((outer diameter side wall/2 - outer diameter lid edge/2)/H), is preferably as small as possible and is most preferably equal to 0.

Fig. 14 illustrates how the volume inside this base rib (6) can be increased further by reducing the radius R of the base rib (6). According to the invention, the radius R of the base rib (6) is greater than or equal to 0.5 mm and smaller than or equal to 10 mm. Preferably, H is less than 3 mm.

In a third embodiment of a beverage can (1 , ) according to the invention as illustrated in Fig. 15, the base rib (6) is furthermore reinforced by means of a curved (concave) continuous circular indentation (10). By means of this indentation (10), the base rib (6) can be of a wider design in order to enable an optimum fit of the lid edge (5). In this way, the base rib (6) can be widened up to the appropriate groove (7). Other ribs (9) of a beverage can (1, ) can be reinforced by means of one or more such indentations (10). Obviously, ribs (6, 9) can be provided with these reinforcing indentations (10) in all possible embodiments of packagings (1 , ) according to the present invention. The indentation (10) may, for example, be in the shape of a groove which is delimited by 2 upright ribs, but can also assume other possible shapes.

In a fourth embodiment of a beverage can (1 , Γ) according to the invention, as illustrated in Fig. 16, the bottom (4) inside the base rib (6) is provided with four grooves (7, 8) with an increasingly smaller diameter, which are in each case delimited by two ribs (6, 9). In this case, the lid edge (5) has a diameter which is such that this fits in the third groove (8) having the smallest diameter but one when stacking such embodiments of beverage cans (1 , Γ) on top of one another. As a result of the design of the beverage cans (1 , 1 '), it is possible to freely determine in which groove (7, 8) the lid edge (5) engages. Here, this could, for example, also engage in the second groove (8). Thus, it is conceivable that, with an increasing number of grooves, the diameter (Dl) of the central concave part (1 1) can be made increasingly smaller. The smaller this diameter (Dl), the flatter or more shallow the central concave part (1 1) can be made, while still satisfying the strength requirements.

Fig. 17 shows a detailed cross section of the bottom profile of the first embodiment of a beverage can (1) with two grooves (7, 8) (which are delimited by ribs (6, 9)), and of the base rib (6) of the third embodiment of a beverage can (1) from Fig. 15.

The base rib (6) in each case extends in line with the side wall (3) and is formed by a radius (R) with which it adjoins the side wall (3), an optional flat part (LI) and a second radius (R2) with which it adjoins the first groove (7). The base rib (6) may, as in the third embodiment, also be designed as having one or more small indentations (10), for example having a radius (rl ), in order to widen and reinforce the base rib (6). The smaller the radius (R) with which the base rib (6) adjoins the side wall and the radius (rl ) of the indentation (10), the more advantageous this is in terms of savings in material and gains in volume.

The grooves (7, 8) are formed by angles (Bl , B2, B3, B4), radii (R3, R4, R6) and optional flat parts (L2). The ribs (9) are formed by radii (R5, R7) and optional flat parts. In alternative embodiments, the grooves (7, 8) and the ribs (9) may, for example, also be constructed from segments.

The base rib (6) forms the support surface when the beverage can (1 , Γ) rests on a flat surface. The other ribs (8) and the central concave part (1 1 ) are slightly higher (HI , H2, H3). The central concave part (1 1) may comprise several radii in order to make a good fit of the combination possible and in order to optimise strength requirements.

Fig. 18 again illustrates diagrammatically how the base rib (6) can be made wider without loss of strength by means of indentations (10) in the base rib (6). Figs. 19 and 20 show alternative embodiments of the lid edge (5) resting on the left- hand (Fig. 19) or right-hand (Fig. 20) flank of the groove (7). In this case, the tolerance can be chosen freely as a function of, inter alia, strength, the optimization of the base rib (6) and the optimization of the profile of the inside of the bottom (4). Alternatively, the lid edge (5) can be fitted centrally in the groove (7), without tolerance left or right. These figures furthermore show how the lid edge (5) is seamed.

Fig. 21 diagrammatically illustrates how the bottom (4) of a beverage can (1, Γ) according to the invention can be reinforced further by giving one or more ribs (6, 9) a negative angle (β). This negative angle (β) can either be produced by an adjustment of the die which is used to form the bottom (4) or, if the die could no longer be detached as a result thereof, by reforming this rib (6, 9) by folding it towards the outside of the bottom (4). Folding the rib (6, 9) may be effected, for example, by pushing it towards the outside of the beverage can (1 , 1 ') by means of a force on the bottom side of the rib (6, 9) (see arrows in Figs. 22, 24, 26), so that the top of the rib (6, 9)) (which is situated furthest from the rest of the beverage can (1 , 1 ')) is directed towards the inside of the bottom (4). Such a negative angle (β) can of course be produced on all possible embodiments of packagings (1, ) according to the invention. Embodiments of beverage cans ( 1 ) having such ribs (6, 9) with negative angles (β) are illustrated in Figs. 22 to 30. It is also conceivable for a profile to be introduced in the rib in this manner.

In the sixth embodiment of a beverage can (1) according to the invention as illustrated in Figs. 22 and 23, the bottom (4) comprises a groove (7) which is delimited by two ribs (6, 9) with the inner rib (9) which adjoins the central concave part (1 1) of the bottom (4) comprising a negative angle (β).

In the seventh embodiment of a beverage can (1) according to the invention, as illustrated in Figs. 24, 25 and 28, the bottom (4) comprises two grooves (7, 8) which are delimited by ribs (6, 9), with the inner rib (9) which adjoins the central concave part (1 1) of the bottom (4) comprising a negative angle (β).

In the eighth embodiment of a beverage can (1) according to the invention, as illustrated in Figs. 26 and 27, the bottom (4) comprises four grooves (7, 8) which are delimited by ribs (6, 9), with the inner rib (9) which adjoins the central concave part (1 1) of the bottom (4) comprising a negative angle (β). In the ninth embodiment of a beverage can (1) according to the invention, the bottom (4) as illustrated in Fig. 29 comprises two grooves (7, 8) which are delimited by ribs (6, 9), with the two inner ribs (9) comprising a negative angle (β).

In the tenth embodiment of a beverage can (1) according to the invention, the bottom (4) as illustrated in Fig. 30 comprises two grooves (7, 8) which are delimited by ribs (6, 9), with all ribs (9) comprising a negative angle (β).

In the eleventh embodiment of a beverage can (1) according to the invention as illustrated in Fig. 31, the central concave part (1 1) of the bottom (4) is delimited by the base rib (6) which comprises a negative angle (β).

Obviously, endless possible combinations and variants are conceivable with the described features of a beverage can (1, ) according to the present invention and the possible modifications thereof. Thus, in view of the above, it should be clear that starting from a simple shape of a central sphere (central concave part (1 1)) with an optional extension by means of a number of grooves (7, 8) and ribs (9) in the direction of the outer circumference of the packaging (1 , ), finally ending with a base rib (6) which closely adjoins the outer circumference (cylinder), in which the design of both the sphere (1 1) and the grooves (7, 8) and the ribs can vary in cross section, offers a solution for the stated problems regarding strength and volume optimization, and also results in a significant weight reduction due to the concept of the invention. If desired, the stackability can at all times be maintained.

Claims

C L A I M S

Packaging (1, Γ) comprising:

- a lid

(2),

- a side wall (3) which merges into an upright lid edge (5);

- a bottom (4) which comprises a base rib (6), said base rib (6) adjoining the side wall (3);

in such a way that when said first packaging (1) is stacked on top of a similar second packaging (Γ), the lid edge (5) of the second packaging ( ) rests on the bottom (4) of the first packaging (1), inside said base rib (6), characterized in that viewed from the outside of the packaging (1, Γ), the bottom (4) comprises a central part (11) which is of concave design, and in that said base rib (6) is of convex design in the direction of the side wall (3) and has a radius R, said radius R adjoining said side wall (3) at an angle (a).

Packaging (1 , ) according to Claim 1, characterized in that the packaging (1 , Γ) is of substantially cylindrical design, in that the side wall (3) is configured as a cylinder wall, in that the base rib (6) adjoins the side wall (3) at a height H and in that the angle (a) is smaller than or equal to arctan ((the outer diameter of the side wall (3) / 2 - the outer diameter of the lid edge (5) / 2) / H).

Packaging (1, Γ) according to Claim 2, characterized in that the height H is smaller than or equal to the height (s) of the upright lid edge (5) increased by ((the outer diameter of the side wall

(3) / 2 - the outer diameter of the lid edge (5) / 2)/tan (30)).

4. Packaging (1 , ) according to Claim 1 or 2, characterized in that H is less than or equal to 1 1 mm and is preferably between 1 and 3 mm.

5. Packaging (1 , ) according to one of the preceding claims, characterized in that the radius R is greater than or equal to 0.5 mm.

6. Packaging (1 , ) according to one of the preceding claims, characterized in that the central part (1 1) of the bottom (4) adjoins said base rib (6).

7. Packaging (1, Γ) according to one of Claims 1 to 5, characterized in that the bottom (4) comprises at least one groove (7) which is disposed inside said base rib (6), in which, when said first packaging (1) is stacked onto a similar second packaging ( ), the lid edge (5) of the second packaging (Γ) rests on the at least one groove (7) of the first packaging (1).

8. Packaging (1, 1 ') according to Claim 7, characterized in that this groove (7) is delimited by at least one rib (6, 9).

9. Packaging (1 , 1 ') according to Claim 8, characterized in that the groove (7) is delimited by the base rib (6).

10. Packaging (1, ) according to one of the Claims 7 to 9, characterized in that the groove (7) is delimited by two ribs (6, 9).

1 1. Packaging (1, ) according to one of the preceding claims, characterized in that at least one of the ribs (6, 9) comprises one or more indentations (10).

12. Packaging (1 , 1 ') according to Claim 1 1 , characterized in that the one or more indentations (10) are of concave design.

13. Packaging (1, ) according to Claim 1 1 or 12, characterized in that the base rib (6) comprises one or more of said indentations (10).

14. Packaging ( 1 , ) according to one of the preceding claims, characterized in that the bottom (4) comprises two or more grooves (7, 8) of different diameters for receiving a lid edge (5) of one of these diameters.

15. Packaging (1 , Γ) according to one of the preceding claims, characterized in that the bottom (4) comprises one or more reinforced grooves (7, 8).

16. Packaging (1 , ) according to one of the preceding claims, characterized in that the edge of at least one said rib (6, 9) which is turned towards the central part (1 1 ) is substantially positioned at a negative angle (β, B l , B3, R5) with respect to said central part (1 1 ).

17. Packaging (1 , Γ) according to Claim 16, characterized in that the central part (1 1) of the bottom (4) is delimited by said rib (6, 9), with the edge of said rib (6, 9) which is turned towards the central part (1 1 ) being essentially positioned at a negative angle (β, βΐ , B3, B5) with respect to said central part (1 1 ).

18. Packaging (1 , ) according to Claim 16 or 17, characterized in that the edge of the base rib (6) which is turned towards the central part (1 1) is essentially positioned at a negative angle (β, β ΐ ) with respect to said central part (1 1 ).

19. Packaging (1 , ) according to one of the preceding claims, characterized in that the angle (a) at which the radius (R) adjoins the side wall (3) is equal to 0 degrees.

20. Packaging (1 , ) according to one of the preceding claims, characterized in that the inner side of the base rib (6), viewed on the inside of the packaging, is of a concave design in the direction of the side wall (3) and has a radius R', this radius R' adjoining the inner side of the side wall (3) at an angle (γ).

Packaging (1 , ) according to Claim 20, characterized in that the packaging (1 , ) is made from sheet material having a blank thickness (TO), in that the side wall (3) comprises a zone having a minimum wall thickness (d), in which said minimum wall thickness (d) is smaller than the blank thickness (TO) and in which said zone starts at a height h and in that the angle (γ) is smaller than or equal to arctan ((blank thickness (TO) - minimum wall thickness (d))/(h- R)).

22. Packaging (1 , Γ) according to Claim 20 or 21 , characterized in that the packaging (1, Γ) is of substantially cylindrical design, in that the side wall (3) is configured as a cylinder wall and in that said radius R' on the inner side of the base rib (6) is smaller than or equal to (the outer diameter of the side wall (3) - the outer diameter of the lid edge (5)) / 4.

Packaging (1, ) according to one of the preceding claims, characterized in that the diameter of the central part (1 1) of the bottom (4) is smaller than the inner diameter of the lid edge (5).