Cup made of a paper material

A cup made of paper material having a fillable interior is provided. The cup is formed by a conical sleeve and a bottom. The bottom is attached to the sleeve at the lower end of the interior with a bottom skirt in an essentially liquid-tight way. The sleeve and/or the bottom in the area of the bottom skirt and/or the bottom skirt itself includes, at least in one area along the periphery, an outwardly projecting widening. A lower edge of the widening forms a standing surface for the cup. The widening can form a structure for holding another cup of the same type, which structure can act together with a similar cup during stacking. The cup can include a heat-insulting outer sleeve.

FIELD OF THE INVENTION

The present invention relates to a cup made of a paper material and having a fillable interior, which interior is formed by a conical sleeve and a bottom, whereby the bottom is attached with a bottom skirt to the sleeve in an essentially liquid-tight way at the lower end of the interior.

The present invention relates further to a process for producing a cup made of paper material, which consists of a conical sleeve and a bottom attached in the area of the lesser circumference of the sleeve by means of a bottom skirt.

BACKGROUND OF THE INVENTION

A cup of this kind is prior art in Japanese published patent application JP2001-192015A. The bottom skirt of the known cup widens out downwards. The widening serves to fix an outer sleeve, which surrounds the interior defining sleeve by forming a hollow space. As the widening of the bottom skirt defines the distance between the inner sleeve and the outer sleeve, the widening of the bottom skirt along the periphery must be continuous. The outer sleeve is placed around the bottom skirt, folded inwards and attached thereto. When the outer sleeve is being attached to the bottom skirt, it may occur that the liquid tightness of the bottom skirt is affected. The attaching of the outer sleeve by means of folding inwards is a very complicated process.

In the case of the known cup, the outer sleeve surrounds the bottom skirt completely, so that this can no longer be seen from the outside. When the outer sleeve is folded inwards and attached from the inside to the bottom skirt, counter-holding from the outside is no longer possible. The outer sleeve can only be pressed against from the inside with a very low level of force, which the bottom skirt can take up itself. If the pressure force is too great, the bottom skirt may tear; on the other hand, the attaching of the outer sleeve can be inadequate if the pressure force is too low. In the case of attaching the outer sleeve by means of heat sealing it can occur that the sealing between the bottom and the sleeve defining the interior dissolves, as when the inwardly folded outer sleeve is being sealed, no counter pressure can be exerted from the outside on the bottom skirt.

In the case of cups made of paper material, the bottom skirt is a very important element of the cup. The bottom skirt is necessary for the connection between the sleeve and the bottom. At least two material layers are disposed in thickness direction on top of one another, namely the material of the bottom and the material of the interior-defining sleeve. The bottom is advantageously pot-shaped, whose open side faces away from the filling opening of the cup. The at least two material layers are advantageously arranged along the wall of the pot-shaped bottom. It can be additionally provided that for example the sleeve is folded inwards around the material of the bottom, and that the bottom skirt consists of three or more material layers. The material of the bottom is glued or sealed to the material of the sleeve in the area of the bottom skirt, in order that it is liquid-tight for at least a certain time.

The term “paper material”, from which the bottom and the sleeve are made, includes various materials, which comprise at least one layer of paper, paperboard or cardboard. In addition the material can comprise one or more layers made of synthetics and/or aluminium. It can also be provided that the paper material is waxed or coated, in order to provide a resistance against the liquid with which the cup is subsequently filled. The paper material is advantageously coated at least on the side facing the interior with a thin synthetic layer, preferably made of polyethylene. In contrast to purely synthetic material, the formability and in particular the degree to which such paper material is ductile is limited. In the case of too great a deformation, the paper material itself, or a provided coating, may tear, so that the liquid-tight properties are impaired. The bottom skirt is therefore an essential design feature in the case of cups made of paper material and cannot be omitted.

SUMMARY OF THE INVENTION

It is an object of the present invention to simplify the manufacturing process of a cup of the above mentioned type and to avoid difficulties with liquid-tightness at the bottom skirt.

This object has been achieved in accordance with the present invention in that the sleeve and/or the bottom in the area of the bottom skirt and/or the bottom skirt itself comprises at least in an area along the periphery an outwardly projecting widening, and in that a lower edge forms a standing surface for the cup.

The object has been achieved in accordance with the process according to the present invention in that the bottom is joined to the sleeve by the formation of a bottom skirt, whereby during the formation of the bottom skirt, the sleeve and/or the bottom in the area of the bottom skirt and/or the bottom skirt itself is widened outwards in at least one area along the circumference so that a lower edge of the widening forms a standing surface for the cup.

The standing surface of the cup is enlarged by means of the widening, even if the widening is only partial, so that the cup acquires an improved stability. The widening is hereby not covered, or not completely covered, by an outer sleeve, so that the material of the sleeve or the bottom directly forms the standing surface. The bottom skirt thus cannot be impaired in its liquid tightness by the application of additional material of the outer sleeve. In an advantageous embodiment, the widening is continuous and formed uniformly along the periphery. When the paper material is coated, it is advantageous to form the widening only to the point where the coating does not tear.

The bottom skirt is advantageously widened along its entire extent. The bottom skirt has then—as seen in axial section—an essentially constant angle of inclination in relation to the middle axis of the cup. In an embodiment it can be provided, however, that the bottom skirt has different height area, which have varying angles of inclination. The area of the bottom skirt bordering the bottom can hereby remain in its original form, while the lower edge of the bottom skirt is widened more and more. The top most height area can serve mainly to seal the fillable interior and joins the conical sleeve with the bottom in an essentially liquid-tight way. In this top most height area, the sleeve and the wall are sealed or glued together. At the lower height area of the bottom skirt, the material of the interior-defining sleeve and/or the wall of the bottom is widened and forms with its lower edge an enlarged standing surface for, the cup. At this height area, a liquid-tight joining of the material of the bottom and the material of the sleeve is no longer absolutely necessary, so that sealing or gluing at the lower height area can at least to some extent be omitted.

The cup according to the present invention is very versatile, as it can be applied without an outer sleeve, or with a variety of different outer sleeves. A heat-insulating sleeve is advantageously provided, which surrounds the interior-defining sleeve while forming a hollow space. The outer sleeve is hereby advantageously slid onto the conical interior-defining sleeve along the middle axis and fixed, after the bottom skirt is formed and widened.

The widening on the bottom skirt can be applied very advantageously in order to improve the stacking properties of the cup. A stackable cup is for example known in European patent EP 1 227 042 B1. The interior-defining sleeve of the known cup comprises a first means for holding another cup of the same type. The known cup comprises a second holding means on an outer sleeve, which surrounds the interior-defining sleeve with a heat-insulating hollow space. The second holding means is formed by a curled part rolled inwards and applied to the lower end of the outer sleeve. When the cups are stacked, the second holding means applied to the outer sleeve can act together with a first holding means applied to a similar cup. A number of cups stacked on top of one another form hereby a stable stack, in which the stacked cups rest securely on top of one another, without however wedging in each other. As wedging of the stacked cups is prevented, the individual cups can therefore be very easily removed from the stack.

The known cup has the disadvantage in that the forces occurring in stacking are relayed through the interior-defining sleeve and through the outer sleeve. The forces, which must be relayed within the cup from the first holding means to the second holding means, are first transferred through the interior-defining sleeve to connecting points between the inner sleeve and the outer sleeve and relayed via these connecting points to the outer sleeve. In the outer sleeve the forces are relayed to the second holding means formed as an inwardly rolled edge and there transferred to the next cup. The inner sleeve and the outer sleeve must be sufficiently stable in order to take up the occurring forces. In addition, the connecting points between the outer sleeve and the inner sleeve must be designed to take up the maximum occurring forces.

The scope of the design of the cup according to European patent EP 1 227 042 B1 is disadvantageously limited, as the second holding means applied to the outer sleeve must always be adapted to the dimensions of the first holding means of another cup of the same type, and also to the relayed forces. It is not possible to provide the outer sleeve with an optional form, or to alter its form as required. It is also not possible to omit the outer sleeve in case of need without losing the good stacking properties.

In the cup according to the present invention it is provided that a means for holding another cup of the same type is arranged on the bottom skirt, which means can act together with a similar cup when the cup is stacked. The holding means is advantageously formed by the widening. It is advantageously provided that a first holding means is arranged on the interior-defining sleeve, which first holding means can act together with a second holding means applied on the widening of a similar cup when the cup is stacked.

The stackable cup is advantageously produced in a process by means of the following procedural steps:forming of at least one first means for holding another cup of the same type on the interior-defining sleeve;forming of a second means for holding on the bottom skirt, which second holding means can act together with a first holding means applied to a similar cup when the cup is stacked.

The second holding means is hereby arranged on the interior-defining sleeve or on the bottom, or on a bottom skirt connecting the interior-defining sleeve with the bottom. In any case, the second holding means is applied to a component of the cup which is in contact with the fillable interior.

The cup according to the present invention has the advantage in that, even without an outer sleeve, the cup can be reliably stacked in a stable manner without wedging and easily de-stacked again. If it is provided that the cup should be assigned a heat-insulating outer sleeve, this can be achieved to a great extent independently and free of the limitations of the cup in European patent EP 1 227 042 B1. The forces occurring during stacking are simply relayed within the interior-defining components from the first holding means to the second holding means. An outer sleeve is thus not absolutely necessary. If, however, an outer sleeve is to be provided, it is not loaded by the forces occurring during stacking. The bottom skirt, by means of which the interior-defining sleeve is connected to the bottom, is a very stable part of the cup and is very well suited to taking up the forces. The forces occurring during stacking are relayed essentially by the interior-defining sleeve from the first holding means to the second holding means, which second holding means can be formed by the widening of the bottom skirt. This permits the formation of a very stable stack comprising a large number of cups, which do not become wedged inside one another even when the stack is subjected to knocks or is for example placed abruptly on the ground. The bottom and the interior-defining sleeve are in any case strong enough to take up the forces occurring during stacking, as they also must take up the forces occurring during filling.

In order to prevent a number of cups wedging during stacking it is advantageous that the dimensions of the second holding means are adapted to the dimensions of the first means for holding another cup of the same type. The first means for holding another cup of the same type can hereby be optionally formed. It is, however, essential that a contour is formed which can take up forces acting in axial direction of the cup, that is, the forces which act between two cups during stacking. The first holding means is advantageously designed as a bead or a rib, which is at least formed in one area along the circumference of the interior-defining sleeve. The bead or rib can be designed continuously along the circumference or with interruptions.

If, in an embodiment of the present invention, it is provided that the cup comprises a heat-insulating outer sleeve, the design of the heat-insulating outer sleeve is hereby optional. The outer sleeve can for example be made of synthetic, paper or composite material. In order to improve the insulation effect, the outer sleeve can also be corrugated, fluted, embossed or comprise a foam layer. The outer sleeve can be designed as a multi-layered sleeve, for example a corrugated intermediary layer can be provided, which is then covered over by a smooth outer layer. As the cup according to the present invention can be stacked independently of the type of outer sleeve, one and the same inner cup can be combined in a simple and almost endless variety of ways with a variety of outer sleeves. Without changing the shape and dimensions of the inner cup or the components forming the fillable interior, a variety of cups having various optical and haptical designs can be created, owing to the fact that the appearance of the cup as seen by the consumer is mainly defined by the design of the outer sleeve.

In a process for manufacturing a double-walled cup, the following procedural steps are advantageously executed:forming of at least one first means for holding another cup of the same type on the sleeve defining the interior;forming of a widened bottom skirt and pressing of the interior-defining sleeve and the bottom;forming of a second holding means at the bottom skirt, which second holding means can act together with a first holding means applied to a similar cup when the cup is stacked;sliding on of a tube-shaped pre-formed outer sleeve over the interior-defining conical sleeve in axial direction;fixing the outer sleeve to the interior-defining sleeve.

The fixing of the outer sleeve on the inner sleeve can take place for example by means of sealing or gluing. This effects a secure connection between the outer sleeve and the interior-defining sleeve, so that the outer sleeve is reliably prevented from slipping, even if the outer sleeve has only a low height.

In order to achieve a good appearance of the cup, it is advantageous that the outer sleeve ends below the first means for holding another cup of the same type, or even below the bottom. The first holding means applied to the inner sleeve is thus covered over by the outer sleeve and is no longer visible from the outside. Furthermore, it is advantageous when the outer sleeve ends above the widening of the bottom skirt.

The widening of the bottom skirt advantageously takes place by means of the dual action of a tool arranged outside and inside of the bottom skirt. Therefore, the widening can be formed very precisely.

The widening is advantageously spread outwards to such a degree that a parallel to the interior-defining sleeve disposed on the lower edge of the widening, extends at a certain distance outside of the interior-defining-sleeve. In order that a provided outer sleeve does not prevent the stacking of the cups, it is advantageous that the outer contours of the outer sleeve are located within the parallel to the interior-defining sleeve, which parallel is disposed on the widening of the bottom skirt.

DETAILED DESCRIPTION

The cup1shown inFIG. 1consists essentially of a conical sleeve2and a pot-shaped bottom3. The open side of the pot-shaped bottom3is arranged in such a way that it is facing away from the filling opening of the cup1. The bottom3with its wall31is joined liquid-tight to the sleeve2in the area of its smallest diameter by means of the formation of a bottom skirt4. In the area of the bottom skirt4, the material of the sleeve2is placed around the wall31of the bottom3and folded inwards. The sleeve2and the bottom3form a fillable interior5of the cup1. The fillable interior5has a height A. The sleeve2defining the interior5comprises on its top rim, that is, in the area of its largest circumference, an outwardly rolled lip6, which surrounds the filling opening.

The conical feature of the sleeve2is hereby understood in that the sleeve2tapers in longitudinal section as shown inFIG. 1from the lip6to the bottom3at least in certain areas. The sleeve2comprises hereby in the area of the fillable interior5above a bead8an angle of inclination a to the middle axis13of the cup1. The sleeve2below the bead8has a cylindrical form reaching to the bottom3. The form of the sleeve2in cross section is hereby irrelevant. The sleeve2is advantageously circular in cross section, but can alternatively be oval for example, or rectangular with rounded corners. The cup1has a truncated cone shape in the case of a round cross section of the conical sleeve2, while in the case of a rectangular cross section of the cup, the conical sleeve2has more likely a truncated pyramid shape.

The bottom skirt4comprises at least in the area along its periphery an outwardly projecting widening10. A widening should be understood in this present case in that the bottom skirt4, in relation to a circular cylinder around the middle axis13, flares outward, so that the bottom skirt encircles a cross section area which enlarges downwards towards the standing surface. A lower edge14of the widening10on the bottom skirt4forms the standing surface for the cup1. The cup1stands, when in use, on its standing surface, which is enlarged by the widening10. This makes it difficult for the cup1to tip over. The widening10is advantageously designed continuously around the circumference of the bottom skirt4.

The outwardly projecting widening10also forms means9for holding another cup1′ of the same type, which means can act together with a similar cup1′ when the cup is stacked. The stacking of the cup1in a similar cup1′ is shown inFIG. 2. The widening10, as a means9for stacking the cup1, can hereby for example act together with a sleeve2′ defining the interior5′. Further stacking means are not absolutely necessary.

The sleeve2defining the interior5advantageously comprises a first means7for holding another cup1of the same type, which means can be optionally formed. It is important that the first holding means7comprises a contour which can take up forces acting in the direction of the middle axis13of the cup1, that is, forces which act between two cups during stacking. The first holding means7can be formed for example by means of a rib or a bead8, which projects into the interior of the cup1. The above mentioned second means9in the form of a widening10is arranged to the bottom skirt4, at which the sleeve2defining the interior5is folded around the pot-shaped, deep drawn bottom3and fixed liquid-tight thereto.

The dimension Y of the second holding means9is adapted to the dimension X of the first means7for holding another cup1′ of the same type. In the case of a circular cross section of the cup1, the dimension X of the first holding means7corresponds to the inner diameter of the sleeve2above the bead8. The dimension Y of the second holding means9corresponds to the largest outer diameter of the widening10at the bottom skirt4, that is, the diameter which the widening10encloses. The adaptation of the dimensions X and Y take place in that the dimension Y is somewhat smaller or at maximum is the same size as the dimension X.

The interaction of the first means7for holding and the second means9for holding is evident in the cups1and1′ shown inFIG. 2. The first means7′ of the cup1′ applied to the sleeve2′ defining the interior5′ takes up the second means9of the cup1. The widening10applied to the bottom skirt4of the cup1, and in particular the bottom end of the widening10, that is approximately the standing surface at the lower edge14, is supported hereby on the bead8′, which is formed into the sleeve2′. Because of the above mentioned adaptation of the dimension X of the first holding means7to the dimension Y of the second holding means9, it is ensured that the widening10of the cup1stands on the bead8′ in a secure and stable way, without however wedging itself in the conical sleeve2′. The forces which occur along the middle axis13during stacking, for example the forces of weight of the cup1or of the cups stacked on top of it, are taken up reliably by the bead8′ as the holding means7′ and relayed via the sleeve2′ to the lower edge14′ of the bottom skirt4′ of the lower cup1′, and passed on to the ground from the lower edge14′ located at the standing surface. This ensures the easy removability of the cup1or1′ when the cups are de-stacked, even when very high forces in the direction of the middle axis13occur.

In order to achieve a sufficiently large widening10having a correspondingly large dimension Y without adversely affecting the liquid tightness of the sleeve2, it is advantageous when the height of the widening10—as can be seen in FIG.1—extends essentially over the entire height B of the bottom skirt4. As seen in axial section ofFIG. 1, the bottom skirt4comprises a constant angle of inclination β in relation to the middle axis13of the cup1. The angle of inclination β of the height area B of the bottom skirt4is aligned in any case in such a way that the bottom skirt4widens towards the lower edge14and has its widest dimension Y at its lower edge14, that is, the lower edge14of the bottom skirt4forms the area of the bottom skirt4which is furthest from the middle axis13as seen parallel to the middle axis13. In contrast to the angle of inclination a of the sleeve2in the area of the interior5, the angle of inclination β is so aligned that the conicity extends in the opposite direction.

The diameter Y surrounding the widening10is hereby advantageously larger than the diameter D, which surrounds the area of the bottom3, which is in contact with the interior5. In order to permit effective stacking, and that the stacking height is not unnecessarily high, it is advantageous when the holding means7assigned to the sleeve2defining the interior5is not arranged higher above the bottom3than a third of the height A of the interior5. Even if the means7is omitted, and the widening10is supported directly on the conical area of the sleeve2, the diameter Y enclosing the widening10is advantageously smaller than a diameter enclosing the inner contour of the sleeve2at a height above the bottom3of approximately a third of the height A.

The rib or the bead8can be stamped or rolled by forming tools, which are placed to the sleeve2in axial or radial direction of the cup1. The diameter W enclosing the first means7for holding another cup1′ of the same kind, that is the inner diameter W of the bead8, is approximately as large as diameter D surrounding the area of the bottom3which comes into contact with the inner space5. The sleeve2defining the interior5is as a result essentially cylindrical between the first holding means7and the bottom3.

The widening10at the bottom skirt4can for example be formed by a cone-shaped mandrel, which is placed to the bottom skirt4from below. If required, the bottom skirt4can be heated for the purposes of forming the widening10. Because a forming tool, which executes a sliding motion in relation to the surface of the bottom skirt4, can very easily form creases, it can therefore also be advantageous to form the widening10by means of a rolling tool or by means of a tool which spreads out in radial direction. It can hereby be advantageous to assign to the outer circumference of the bottom skirt4a correspondingly formed counter tool, in order to support the formation of the widening10. A particularly advantageous process for manufacturing the cup1is described in more details below with the aid ofFIGS. 6 to 8.

FIG. 3shows in the individual drawings A to C in schematic form various embodiments of the cup1the area of the bottom skirt4. In the variations in the remaining Figures, the bottom skirt4is always formed by three layers of material, namely by two layers of the sleeve2, which surround the wall31of the pot-shaped bottom3on the inside and on the outside. This embodiment is often very advantageous, but is not absolutely necessary in order to realize the present invention. In the case of specified requirements, the following variations could also be advantageous.

It is provided inFIG. 3Athat the material of the bottom3is folded outwards and encloses the material of the sleeve2. The lower rim14of the widening10, which forms the standing surface for the cup1, is hereby formed by the material of the bottom3.

InFIG. 3Ban embodiment is shown in which the bottom skirt4is formed by two material layers. The material of the sleeve2and the wall31of the bottom3end both at the lower rim14and thus form the standing surface.

InFIG. 3Can embodiment of the bottom skirt4of the cup1is shown in which the bottom skirt4in its height area B has various angles of inclination in relation to the middle axis13. Depending on the height B of the bottom skirt4and the desired dimension Y of the widening10, it can be sufficient to provide only a part area within the height area B with a widening10. The remaining area can, for example, be essentially cylindrical, so that the bottom skirt4extends there approximately parallel to the middle axis13. For small widenings10it can be sufficient that the angle α of the sleeve2in the area of the interior5is continued unchanged in the upper area of the skirt by the sleeve2.

Although not shown inFIGS. 1 to 3, it can be advantageous to assign the cup1an outer sleeve, which surrounds the sleeve2defining the interior5while forming a hollow space. In order that the stacking of the cup1is not impaired, it can be advantageous that the outer contour of the outer sleeve is located within a parallel15to the sleeve2defining the interior5, whereby the parallel15is disposed on the widening10of the bottom skirt4. As long as an outer sleeve is located within the space16between the parallel15and the sleeve2defining the interior5, the stacking properties of the cup are not influenced in any way. The design possibilities are thus endless. It is also possible to equip a common embodiment of the cup1with variously designed outer sleeves, without having to change the first holding means7and the second holding means9. Several possible embodiments for outer sleeves of this type are described below with the aid ofFIGS. 4 and 5.

The cups1shown inFIGS. 4 and 5each comprises a heat-insulating outer sleeve17, which surrounds the sleeve2defining the interior5partly under formation of a hollow space18. Cups of this type are defined as double-walled insulating cups, in which the sleeve2, in conjunction with the bottom3, located inside of the outer sleeve17can be defined as an “inner cup”. The first means7for holding another cup1′ of the same type and the second holding means9are designed analogue to the embodiment described inFIG. 1, so that a repeat description can be omitted.

The outer sleeve17of the cup1shown inFIG. 4is arranged essentially parallel to the sleeve2defining the interior5. The outer sleeve17comprises on an upper and on a lower end inwardly rolled curled parts19and20and is supported by the curled parts19and20on the sleeve2defining the interior5. It can be provided that the outer sleeve17is fixed in the area of the curled part19and/or20, for example by means of gluing. The curled part20is supported on the inner sleeve5in the area of the bottom skirt4, that is below the horizontal bottom3, as a result of which the outer sleeve17is very stable. At the same time the outer sleeve17also covers the first holding means7, so that this is not recognizable from the outside. The curled part20comprises an area23extending parallel to the outer sleeve17. The area23extends in close proximity to the inner side of the outer sleeve17and may be disposed on said inner side. The sliding of the outer sleeve17onto the sleeve2is simplified as a result of the area23extending parallel to the outer sleeve17, as the outer sleeve17can no longer get stuck on the bottom skirt4.

InFIG. 5, the sleeve2defining the interior5comprises an abrupt change in size in the form of a shoulder21in the area below the lip6, which shoulder21presents itself as an abrupt increase of the cross section when seen from the bottom3to the lip6. The outer sleeve17is attached in the area between the lip6and the shoulder21to the sleeve2defining the interior5, for example by means of sealing or gluing. At its lower end the outer sleeve17comprises an inwardly rolled curled part20, which also comprises an area23extending parallel to the outer sleeve17. The curled part20is supported below the bottom3on the bottom skirt4. The curled part20is in contrast toFIG. 4, pressed flat and is slightly compressed at the lower edge area24of the outer sleeve17, so that a greater conicity of the outer sleeve17is present in this area.

In contrast to the depiction shown inFIG. 5, the cup1can be designed differently in the area of the shoulder21. An advantageous variation in the area of the shoulder21is shown greatly enlarged inFIG. 5A. The area of the sleeve2defining the interior5, which lies between the lip6and the shoulder21and which is denoted by the reference number25, comprises, in contrast to the depiction shown inFIG. 5, another angle of inclination to the middle axis13than the rest of the sleeve2. InFIG. 5A, the area25of the sleeve2extends between lip6and the shoulder21approximately parallel to the middle axis13. In order that the outer sleeve17can be placed to a small degree underneath the lip6when the outer sleeve17is slid onto the inner cup1, the upper edge area26of the outer sleeve17is slightly compressed. The edge area26does not uniformly extend the conical outer sleeve17, but rather comprises a somewhat tapering diameter. If the outer sleeve17, as shown inFIG. 5A, is pushed slightly with its upper edge into the lip6, the cup1obtains particularly good outward appearance, as the upper edge of the outer sleeve17is no longer visible, If the outer sleeve17is pushed further into the lip6in an embodiment not shown, the wedging of the outer sleeve17effects a fixing of the outer sleeve17by means of the material of the lip6. For certain applications, the wedging of the outer sleeve17in the lip6can be sufficient to provide the only attachment of the outer sleeve17.

The bead8of the first holding means7in the case of the cups is adapted to the dimension Y of the second means9for holding another cup1′ of the same type. When the dimensions X and Y of the cups in theFIGS. 4 and 5comprising the various outer sleeves17are identical, all these various cups1can be stacked together in any combination without wedging, as all the outer sleeves17lie within the space16between the parallel15and the sleeve2defining the interior5. In order to vary the optical and haptic appearance of the cup1, the outer side22of the outer sleeve17can comprise various patterns and textures. The outer side22can for example be corrugated, fluted, embossed or comprise a foamed coating. It can also be provided that the outer sleeve17has a fluted design, and also to provide additionally the outer side22with a smooth cover of the fluted structure in the form of a further sleeve, in order to improve the insulating properties of the cup1.

In particular the embodiment of the outer sleeve17comprising an upper curled part19, or an attachment of the outer sleeve17in the area of the shoulder21of the sleeve2, has the advantage in that in an area closely below the lip6, already a very wide hollow space18occurs between the sleeve2and the outer sleeve17, which provides a very high insulating effect. The curled part19or the shoulder21ensure, even without additional means, for example foam coatings or corrugated paperboard layers within the hollow space18, that the distance between the sleeve2and the outer sleeve17does not decrease even under pressure, for example from a hand gripping the cup1, and that the insulation effect is not lost.

In the production of a cup according toFIG. 1, a conical sleeve2and an approximately pot-shaped bottom are formed. As can be seen inFIG. 6, the sleeve2initially has the form of a conical tube and the bottom3has the form of a truncated cone, which tapers parallel to the sleeve2. In the state shown inFIG. 6, the bottom3and the outer sleeve2are not yet joined to one another, but rather are inserted into one another. The outer sleeve2is placed hereby upon a mandrel30, which has a truncated cone-like shape in a first area29, to which a further truncated cone-shaped surface32adjoins the tapered end of the truncated cone-shaped area29, which cone-shaped surface32tapers more and which is provided for the formation of the bead8(seeFIG. 1). Joined to the surface32is a circular cylinder-shaped area33, at whose free end the bottom3is disposed. A diameter E of this circular cylinder-shaped area33can be smaller than the diameter D of the bottom, for example approximately 0.5 mm smaller (see alsoFIG. 1). As the bottom3and the sleeve2are not yet joined together by means of sealing or gluing, the sleeve2can be somewhat more compressed for the formation of the bead8than would be possible in the case of an already sealed sleeve2and bottom3. As the sleeve2as well as the bottom3consist of coated paper material, the bottom3can at least be compressed to a small degree. It is then possible to draw the bead8relatively far into the interior of the cup1in order to ensure reliable stacking of a number of cups.

Surprisingly, it is actually possible to draw the bead8beyond the diameter D of the bottom3further into the interior. A truncated cone-shaped area would adjoin the bead8in the direction towards the bottom3in the case of a finished cup1, the conicity of said truncated cone-shaped area would be inverse to the remaining sleeve2, which would widen again from the bead8to the bottom3.

In addition to the mandrel30, a form tool34is used for the formation of the bead8, which form tool34is shown inFIG. 6and which is moved upwards in the direction of the arrow35towards the mandrel30. The form tool34has a truncated cone-shaped surface36, its conicity corresponding essentially to the surface32of the mandrel30. The outer tube2is thus clamped between mandrel30and form tool34and the bead8is formed between the surfaces32and36.

The lower end37of the sleeve is simultaneously folded by the form tool34, so that it takes up the position shown inFIG. 6by means of the broken line. For this purpose, the form tool34comprises a groove like area38, which is shown only in sections in the sectional view of the form tool34inFIG. 6, but which extends over 360°. The simultaneous folding of the lower rim37of the sleeve2during the formation of the bead8facilitates the production of the cup according to the present invention.

The sleeve2is wound from a circular ring segment over a mandrel and then glued or sealed along a longitudinal seam. In order to facilitate the folding over of the lower edge37of the sleeve2by means of the form tool34, the longitudinal seam of the sleeve2may not be glued or sealed in the area of the lower end37. This area is denoted with the reference letter F in the drawing inFIG. 6. When the longitudinal seam in area F is not glued or sealed, the sleeve2can be shaped more freely when folded and flute formation in the paper material, which is in principle difficult to form, is avoided. The area F can extend from the lower edge37of the sleeve2to the bottom edge of the bottom3, as denoted inFIG. 6also with the reference F′. The length F and F′ is thus variable and can be altered.

Subsequent to the forming of the bead8and the folding of the lower end37of the sleeve2, the inner cup1is completed in that the bottom3with the sleeve2is joined to the bottom skirt4. This is done with the aid of an outer ring and an inner tool, whereby the widening of the bottom skirt4and the joining of the bottom3with the sleeve2is carried out simultaneously, so that the bottom skirt4in its form widening in the direction towards the lower edge14arises, as shown inFIG. 1. This is described below with the aid ofFIG. 8.

The drawing inFIG. 7shows a further embodiment of the present invention, whereby in contrast to the embodiment inFIG. 6the sleeve2′ has initially a conical form which then becomes cylindrical at the horizontal bottom3′. Consequently in this embodiment the bottom3′ has a reverse pot form with a circumferential cylindrical wall31. The shape of the mandrel30and the form tool34are identical to the designs disclosed above according toFIG. 6. As a result of the cylindrical shape of the circumferential wall31of the bottom3′ and the cylindrical shape of the lower area of the sleeve2′, wrinkle formation is reduced when folding the lower edge37′ of the sleeve2′ and during the subsequent widening and forming of the bottom skirt4.

Based on the state inFIG. 7with the folded lower edge37, which is denoted by broken lines, the sleeve2′ remains with the bottom3′ on the mandrel30and subsequent to the removal of the form tool34, an outer ring38is moved into the area below the bottom3′. An inner surface of the outer ring38facing the sleeve2′ is pointing outwards and comprises the angle which the bottom skirt4takes up in the final stage. A number of inner flanges39lying opposite the outer ring38are provided, whereby in the drawing inFIG. 8only one inner flange39is shown. In the drawing inFIG. 8, the inner flanges39can be moved outwards in the direction towards the outer ring38, and as a result press the folded edge37′ against the wall31of the bottom3′ and against the inner surface of the outer ring38.

Either the flange39or the ring38, for example, or also the inner flange39and the outer ring38can be heated, so that the then three material layers disposed on top of one another are sealed and thus form the bottom skirt4. A surface of the inner flange39facing radially outwards is arranged parallel to the inward-lying surface of the outer ring38and also has an angle under which the bottom skirt4should be arranged in the final stage.

The inner flanges39are for example part of a mandrel and can be moved radially outwards by means of sliding of a middle part (not shown inFIG. 6). The outer ring38can be designed as a fixed ring or for example as a ring which can be opened in order to facilitate the sliding onto the sleeve2′. Instead of a number of inner flanges39, a rotating roller can for example also be supplied, which exerts a force directed radially outwards in the direction of the outer ring38onto the edge37′ and the wall31, in order to form the bottom skirt4. The cup remains on the mandrel30during the forming out of the bottom skirt4.

The inner cup1is completed subsequent to the formation of the bottom skirt4and can be removed from the mandrel30.

An outer sleeve17is then slid onto the finished inner cup1, seeFIG. 4,FIG. 5. This takes place in such a way that the outer sleeve17is taken up in a ring-like outer tool and a pilot mandrel with a suction head extends through the tapered end of the outer sleeve17. This suction head engages an inner cup1from below on the bottom3, sucks it up and pulls said inner cup1into the tapering outer sleeve17until it reaches the state shown inFIGS. 4 and 5.

For the production of the outer sleeve22, said outer sleeve22is firstly wound from a circular, ring segment-shaped blank onto a mandrel and bound to a truncated cone shaped tube. In the area of the lower tapering end, a rolled part40is formed as shown inFIG. 9. For the production of the cup shown inFIG. 5, the rolled part is then pressed flat until the form of rolled part shown inFIG. 10is achieved. It can be seen that the lower edge of the outer sleeve17, which is formed by the rolled part20, is slightly drawn in and therefore comprises a greater conicity at the lower end, as disclosed-above. In the drawing inFIG. 10, a knurl or a ribbing is indicated on the inner side of the rolled part20. A knurl or a ribbing41on the inner side of the rolled part20can be provided in order to achieve a higher degree of elasticity when sliding the outer sleeve17onto the inner cup1.

As disclosed above inFIG. 5, an inner diameter V of the rolled part20is smaller than the outer diameter Y, seeFIG. 5of the bottom skirt4. When the outer sleeve17is slid on, the end of the outer sleeve17with the rolled part20must be widened somewhat, in order that it can be slid over the bottom skirt4. This widening process is facilitated by the knurling or ribbing41. Furthermore, the longitudinal seam of the outer sleeve17in the area of the rolled part20may not be glued or sealed. This facilitates a certain expansion of the outer sleeve17in the area of the curled part20, so that the outer sleeve17can be slid over the bottom skirt and subsequently contracts again, so that the rolled part20lies on the outer side of the bottom skirt4in the position shown inFIG. 5.

It can be further established that a diameter U at the upper end of the curled part20is larger than the outer diameter Y of the bottom skirt4. This can be seen also inFIG. 5. As the inner diameter of the outer sleeve17is therefore larger at the upper edge of the rolled part20than the outer diameter Y, this upper edge of the curled part20cannot get caught on the bottom skirt4when being slid onto said bottom skirt4. Instead the bottom skirt4runs up the slant, which is formed by the inner side of the rolled part20and when the outer sleeve17is slid further on, the outer sleeve is widened, slides over the area with the largest diameter Y of the bottom skirt4and takes up the position shown inFIG. 5. The inner sleeve17is visibly held on the inner cup1by means of internal stress, as in order to remove the outer sleeve17, the outer sleeve17must be drawn again over the conically widening bottom skirt4.

It should be expressly stated at this point that the various embodiments of the outer sleeve17and other shaping means of the cup1such as the bead8or the shoulder21can be combined optionally as required, and are not restricted to the shown variations. In addition it should be noted that the drawings are not drawn to scale. For the purposes of clarity, the dimensions of the widening10and the angle of inclination of the bottom skirt4are shown larger than to scale.