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EP 0 090 639 B1 |
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EUROPEAN PATENT SPECIFICATION |
(45) |
Mention of the grant of the patent: |
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25.03.1987 Bulletin 1987/13 |
(22) |
Date of filing: 29.03.1983 |
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(54) |
Nestable containers
Ineinander stapelbare Behälter
Récipients emboîtables
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Designated Contracting States: |
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DE FR GB NL |
(30) |
Priority: |
29.03.1982 GB 8209128
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Date of publication of application: |
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05.10.1983 Bulletin 1983/40 |
(71) |
Applicant: Lin Pac Plastic Containers Limited |
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Cippenham
Slough SL1 6BJ (GB) |
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(72) |
Inventors: |
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- Tomkins, David
Amersham
Buckinghamshire (GB)
- d'Silva, Oswald V.
Woodley
Reading
Berkshire (GB)
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(74) |
Representative: Rackham, Stephen Neil et al |
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GILL JENNINGS & EVERY,
Broadgate House,
7 Eldon Street London EC2M 7LH London EC2M 7LH (GB) |
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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[0001] Thin-walled plastics cups and other containers are now commonplace. For transport,
e.g. from a place of manufacture to a place of use, such cups or other containers
are nested together to form stacks. The cups or other containers in such nested stacks
tend to jam together and in an attempt to overcome this each cup or other container
has been provided with stacking means. Such stacking means comprises an internal upwardly-facing
surface and a stacking surface. The surfaces are located in planes normal to the central
axis of the cup or other container. In an upright stack the stacking surface of each
intermediate cup or other container rests on the internal upwardly-facing surface
of the cup or other container below, whilst its internal surface supports the external
surface of the cup above. Such stacking means are sufficient to ensure that the cups
or other containers do not jam together when a stack is formed and handled carefully.
However, when such a stack is subject to an axial shock load by being jolted, for
example when a case of such stacks is unloaded from a vehicle or is subjected to vibration
during transport; the outer edge of the external stacking surface of one cup or other
container overrides the inner edge of the internal upwardly-facing surface of the
cup or other container below. This jams the two cups or other containers together
tightly and this presents a major problem when the two cups or other containers are
to be separated by automatic machinery. This problem is particularly significant with
a stack of cups which is packaged with ingredients in each of the cups. Such cups
are known as ingredient cups and typically the ingredient is a powder which will provide
a beverage when an individual cup is removed from the stack and filled with hot water.
The additional weight of the ingredient means that the weight of each stack is greater
than the weight of a corresponding stack of empty cups. Thus stacks of ingredient
cups are more prone to jamming during transport or when they are unloaded from a vehicle.
[0002] Such a construction is shown in US-A-3288340. The known construction comprises a
nestable cup or other container with a bottom and a side wall, and including stacking
means comprising a circumferential shoulder having an internal, upwardly-facing surface
inclined in a direction downwards and outwards and terminating at an acute angled
convex corner, the surface being either continuous or interrupted to form castellations,
so that, when a plurality of identical cups or other containers are assembled together
into an upright stack, the corner of the cup or other container makes localised contact
with a stacking surface of the cup or other container above, the corner engaging the
stacking surface away from its edge. The above-mentioned disadvantages can be mitigated
by the solution defined in claims 1 and 5.
[0003] Any vertical shock loading applied to a stack of such cups or other containers is
cushioned by resilient deformation of the stacking surface. Further, since the internal
upwardly-facing shoulder is inclined outwards and downwards, after the stacking surface
has been deformed, both shoulder and stacking surface are inclined outwards and downwards
and therefore axial shock loading between these surfaces generates forces tending
to expand the stacking surface and contract the internal shoulder, so resisting the
external shoulder overriding the internal shoulder.
[0004] The internal upwardly facing shoulder may be castellated with alternate lands being
inclined. In this way the lower edge of the inclined lands merge with the lands that
lie in a plane normal to the axis of the cup or other container and thus the stacking
surface of the cup above rests on the acute-angled convex corners at the upper ends
of the inclined lands. When a stack of such cups is subjected to axial shock loads
the stacking surface is deformed only in the areas in engagement with the upper ends
of the inclined lands. This deformation absorbs the shock loading and then the lands
lying in a plane normal to the axis of the cup or other container are engaged by the
remainder of the stacking surface of the cup or other container above and this provides
a positive stop. Again the deformed parts of the stacking surface of the cup or other
container above and the inclined lands generate forces tending to expand the stacking
surface so resisting the stacking surface overriding the internal upwardly facing
shoulder.
[0005] The internal upwardly facing shoulders of the stacking means may be located anywhere
along the side wall of the cup or other container. In ingredient cups, the internal
upwardly facing shoulder is usually located at and used to define the top of the ingredient
pocket in the cup or other container. In this case it is preferred that the inner
upwardly facing shoulder is formed by a continuous annular downwardly and outwardly
inclined surface. With such a construction a continuous seal is provided all around
between the upper corner of this surface and the stacking surface of the cup or other
container above so holding the ingredient in its pocket and preventing its migration
during transport and handling.
[0006] According to this invention the resistance to the overriding of the stacking means
of such cups is increased still further by modifying the side wall of the cups or
other containers to include a plurality of circumferentially spaced externally projecting
nibs having bases inclined downwards and outwards around the stacking means and arranged
so that when a plurality of identical cups or other containers are nested to form
an upright stack, the nibs on the upper cup or container are very close to, or touch,
the interior of the side wall of the next cup below.
[0007] Some of any axial shock loading applied to the stack is absorbed by resilient deformation
of the side wall where it is engaged by the nibs and also the nibs help in centralising
the cups or other containers in the stack so that there is the optimum overlap between
the stacking means of adjacent cups or other containers. Since the base of each nib
is also inclined downwardly and outwardly this helps increase the digging in effect
of the nib into the side wall of the cup or other container below and so increases
its resistance to overriding of the stacking means.
[0008] Whilst these cups and other containers are specifically intended to be used with
thin-walled plastic cups, they can also be applied to all manner of thin-walled, thick-walled,
multi-walled, lockable, jamming, non-lockable and stackable containers, made of a
variety of materials such as plastics or paper, using a variety of manufacturing techniques
provided that the downwardly facing shoulders of the stacking means have some inherent
resilience so that they can deform to absorb any axial shock loading.
[0009] Typically when made from a plastics material the cups or other containers are made
from high impact polystyrene, other grades of polystyrene, polypropylene, or polyvinyl
chloride. In each case the shape of the cup is determined by the shape of the cavity
in the female mould, which operates as a rigid unit apart from an ejector in its base.
The deformation of a heated sheet of plastics is started mechanically by a plug, and
is finished by the admission of air under pressure to the interior of a pre-form created
by the plug. There is no use of vacuum and thus the apparatus is simple.
[0010] Preferably the corners of the mould which produce the sharp acute-angled corner along
the upper edge of the internal upwardly facing shoulder has a radius in cross section
not exceeding 0.25 mm, and the corners in the mould which produces the other corners
at the edges of the upwardly and downwardly facing shoulders also have a radius in
cross section not exceeding 0.25 mm.
[0011] Preferably the surface of the mould which forms the inner upwardly facing shoulder
is inclined downwards and outwards at an angle of 7° to the horizontal. This angle
may be varied within the range 5° to 10° to the horizontal.
[0012] Particular examples of plastics cups in accordance with this invention will now be
described and contrasted with the prior art with reference to the accompanying drawings;
in which:
Figure 1 is a sectional elevation through two conventional ingredient cups nested
together;
Figure 2 is a sectional elevation through two conventional nested ingredient cups
which have become jammed together;
Figure 3 is a sectional elevation through one ideal form of ingredient cup;
Figure 4 is a sectional elevation through a first example;
Figure 5 is a section through two of the first example of ingredient cups;
Figure 6 is a section through two of the first example of ingredient cups nested together
illustrating the deformation of the cups caused by axial loading;
Figure 7 is a perspective view of a second example of cups;
Figure 8 is a section through two cups in accordance with the second example nested
together;
Figure 9 is a section through two of the second example of cups nested together and
subjected to an axial loading;
Figure 10 is a sectioned perspective view of the first example of cups in accordance
with this invention showing all of its features;
Figure 11 is a section through two of the cups as shown in Figure 10 nested together;
and,
Figure 12 is a section showing a modification.
Figure 1 shows two known nested ingredient cups 1A and 1B under normal conditions.
Each comprises a side wall 2, a base 3 and an annular shoulder 4 extending in a plane
normal to the axis of the cup. The bottom 3 of cup 1A sits on the inner upwardly-facing
surface of shoulder 4 of cup 1 B. An ingredient pocket 6 is formed between the cups
1A and 1B and in use, these contain a beverage powder 7.
Figure 2 shows the effect of an excessive axial load on a nested stack of such cups.
The external corner around the periphery of the bottom 3 of the cup 1A has overridden
the internal corner around the periphery of the shoulder 4 of cup 1 B and so jammed
itself into the ingredient pocket 6 of cup 1B.
[0013] The resistance to jamming of such a stack of cups to an axial shock is a result of
the relationship between the degree of overlap between the shoulder 4 and the bottom
3 of the next cup in the stack. If the degree of overlap shown as X in Figure 3 is
made sufficiently large and the corners 8, 9 and 10 made sufficiently sharp, then
this problem can be overcome. To obtain maximum benefit from the overlap X the corner
10 needs to be sharp on the outside of the cup whilst the corner 9 needs to be sharp
on the inside of the cup. The effectiveness of the overlap also depends upon the cups
being located concentrically in the stack by co-operation between the corner 10 and
the inside of the corner 8. However, to produce cups of this nature using standard
pressure-forming techniques is virtually impossible because of the problem of ensuring
sharp corners and the subsequent ejection of the cups from a mould in which they are
formed. In the past, this has led to the development of complicated and expensive
techniques such as vacuum assisted pressure-forming and drop-based tooling. Figure
4 shows a cup in accordance with this invention formed as an ingredient cup 11. The
annular shoulder 5 between the corners 8 and 9 has a downward and outward slope. Figure
5 shows a stack of two such cups 11A and 11 B and nested together. The sharp acute-angled
corner 9 at the inside of the downwardly and outwardly inclined annular shoulder 5
of the cup 11 B engages the bottom 3 of the cup 11A away from its outer corner 10.
A circular line contact is established between the two cups to define the ingredient
pocket 6. The shoulder 5 is inclined at 7° to a plane normal to the axis of the cups.
[0014] When an axial load is applied to a stack of such cups an upward force is transmitted
by the corner 9 of cup 11B to the bottom 3 of cup 11A away from the corner 10. As
the load is increased the upward force causes an upwards distortion in the bottom
3 of cup 11A until the corner 10 engages the face of the inclined shoulder 5. Thus,
the first thing that happens in the event of a stack of such cups being subjected
to an axial load is that the bottom 3 distorts to absorb some of the axial load. Any
further increase in the axial load involves forces being transmitted over zones of
the bottom 3 of the cup 11A and the inclined shoulder 5 of the cup 11 B. These zones
are in face to face inter-engagement as shown in Figure 6 and each has a significant
extent in the radial direction. Because of the initial downward and outward slope
of the shoulder 5 of cup 11B and the deformation of the bottom 3 of cup 11A both of
these zones are inclined downwards and outwards and hence further axial loading results
in the bottom 3 of the cup 11A tending to expand whilst the shoulder 5 of cup 11 B
tends to contact and these forces interact to positively prevent overriding of the
corner 10 over the corner 9 and as shown in Figure 2. Thus, the inclination of the
shoulder 5 positively prevents the jamming of a stack of nested cups together.
[0015] A typical cup as shown in Figures 4, 5 and 6 may be of 7 fluid ounce (200 ml) capacity,
may be made by thermoforming from a sheet of high impact polystyrene having an initial
thickness of 0.8 mm. Each cup uses a disc 74.5 mm in diameter. The deformation of
the heated sheet is started mechanically by a plug and is finished by the emission
of air under pressure into the interior of the preform created by the plug. Preferably
the corners in the mould which produce the corners 8, 9 and 10 in the cup all have
radii in cross section not exceeding 0.25 mm. It is preferred that for most of the
particular cup the measurements of the vertical centre line of the mould are as follows:
to the corner forming corner 8 of the cup 30.00 mm
to the corner forming corner 9 of the cup 29.00 mm
to the corner forming corner 10 of the cup 29.75 mm.
[0016] In the finished cup the thickness of the sheet around the shoulders 4, 5 and in the
bottom 3 is preferably nowhere less than 0.15 mm.
[0017] The second example of cup in accordance with this invention is shown in Figure 7
and in this second example the continuous inclined annular shoulder 5 is interrupted
to form a castellated shoulder. First, in this example a series of shoulders 5 (lands)
inclined to a plane normal to the axis of the cup is intercollated with lands 4 which
lie in a plane normal to the axis of the cup. A normal stack of such cups is shown
in Figure 8 and the bottom 3 of cup 12A is normally supported on the corners 9 of
the inside edge of the inclined lands 5. When the stack of cups is subjected to an
axial load the bottom 3 of the cup 13A is subjected to local deformation as shown
in Figure 9 in an analogous fashion to that of the first example and this deformation
of the bottom 3 of the cup 12A absorbs the shock of any axial loading. After the bottom
3 of the cup 12A has been deformed the corner 10 moves down into contact with the
corner 8 to provide a positive stop. This is the position shown in Figure 9. Again
the deformed parts of the bottom 3 resting against the inclined lands 5 tend to cause
the corner 10 to expand circumferentially and the corner 9 to contract circumferentially
so tending to oppose overriding of the corner 10 over the corner 9.
[0018] Both examples of cups in accordance with this invention include a number of radially
extending nibs 14 located immediately above the inclined annular shoulder 5. This
feature will be described in detail with reference to Figure 10 which is the first
example. The nibs 14 are arranged so that there is minimal or possibly zero clearance
between the apeces of the nibs 14 of cup 13A and the side wall 2 of the cup 13B when
cup 13A is nested inside cup 13B as shown in Figure 11. When the stack of such cups
is subjected to an axial load the outer periphery of the bottom 3 distorts in a similar
fashion to that already described. At this point the apeces of the nibs 14 on the
cup 13A begin to dig in and deform the side wall 2 of the cup 13B. This digging in
and deformation provides an additional force to absorb the shock of any axial load
and decreases the restoring force to return the cups to their normal nested configuration.
The nibs 14 also have the effect of centralising the cups together which again helps
to prevent the corner 10 overriding the corner 9 as a result of any misalignment between
adjacent cups of the stack.
[0019] A modification is shown in Figure 12 and in this modification the nib 14 has a steeply
inclined base 15. The steeply inclined base 15 increases the sharpness of a corner
16 between the apex of the nib 14 and its base and helps to increase the digging in
effect of the nib 14 into the side wall 2 of a cup below it in a stack, thus increasing
its resistance to impaction still further.
[0020] For the sake of clarity, only two cups have been shown throughout this description
to represent a stack of cups and any locking means to lock together the cups into
a stack has been omitted. In practice, a stack of ingredient cups after being filled
with ingredient powder 7 is usually encased in a sheath of plastics film and then
a number of such stacks are packaged in a cardboard case before being transported.
1. A nestable cup or other container comprising a bottom (3), a side wall (2), and
stacking means including a circumferential shoulder having an internal, upwardly facing
surface (5) inclined in a direction downwards and outwards and terminating at an acute
angled convex corner (9), the surface being either continuous or interrupted to form
castellations so that, when a plurality of identical cups (11, 12, 13) or other containers
are assembled together into an upright stack, the corner (9) of the cup (11B, 12B,
13B) or other container makes localised contact with the stacking surface of the cup
(11A, 12A, 13A) or other container above, the corner (9) engaging the stacking surface
away from its edge (10), characterised in that a plurality of circumferentially spaced
externally projecting nibs (14) having bases inclined downwards and outwards are included
around the stacking means and arranged so that when the cups (13A) or other containers
are nested the nibs (14) on the upper cup (13A) or container are very close to, or
touch, the interior of the side wall (2) of the next cup (13B) below.
2. A cup or other container according to claim 1, made from high impact polystyrene,
other grades of polystyrene, polypropylene, or polyvinyl chloride.
3. A cup or other container according to claim 1 or 2, in which the inner upwardly-facing
shoulder (5) is inclined at an angle within a range of 5° to 10° to a plane normal
to the axis of the cup (13) or other container.
4. A cup or other container according to any one of the preceding claims, in which
the thickness of the stacking means (4, 5) and the bottom (3) is nowhere less than
substantially 0.15 mm.
5. A method of making a cup or other container according to any one of the preceding
claims, in which a plastic sheet materials is pressure formed in a female mould having
corners with radii in cross-section not exceeding 0.25 mm.
6. A method according to claim 5, in which the part of the mould which forms the upwardly-facing
shoulder (5) is incined at an angle within a range of 5° to 10° to a plane normal
to the axis of the cup (13) or other container.
1. Ineinander stapelbare Becher oder andere Behälter mit einem Boden (3), einer Seitenwand
(2), und Stapeleinrichtungen, die eine in Umfangsrichtung verlaufende Schulter umfassen,
welche eine innere, nach oben weisende Oberfläche (5) hat, die in einer Richtung nach
unten und nach außen geneigt ist und bei einer tatsächlich spitzwinklig konvexen Kante
(9) endet, deren Oberfläche entweder kontinuierlich oder unterbrochen ist, um Kronen
zu bilden, so daß dann, wenn eine Vielzahl von identischen Bechern (11, 12, 13) oder
anderen Behältern zu einem aufrechten Stapel zusammengesteckt werden, die Kante (9)
des Bechers (11 B, 12B, 13B) oder anderen Behälters einen lokalen Kontakt mit der
Stapelfläche des Bechers (11A, 12A, 13A) oder anderen Behälters darüber macht, wobei
die Kante (9) mit der Stapelfläche von deren Rand (10) entfernt zum Eingriff kommt,
dadurch gekennzeichnet, daß eine Vielzahl von in Umfangsrichtung mit Abstand voneinander
nach außen vorstehenden Nasen (14), deren Basen nach unten und außen geneigt sind,
um die Stapeleinrichtung herum vorgesehen und so angeordnet sind, daß dann, wenn die
Becher (13A) oder anderen Behälter ineinandergestapelt sind, die Nasen (14) auf dem
oberen Becher (13) oder Behälter sehr nahe bei dem inneren der Seitenwand (2) des
nächsten darunter befindlichen Bechers (13B) sind oder diese berühren.
2. Becher oder Behälter nach Anspruch 1, hergestellt aus hochschlagfestem Polystyrol
oder anderen Graden von Polystyrol, Polypropylen oder Polyvinylchlorid.
3. Becher oder andere Behälter nach Anspruch 1 oder 2, bei welchem die innere, nach
oben weisende Schulter (5) unter einem Winkel im Bereich von 5° bis 10° zu der Ebene
geneigt ist, die senkrecht zu der Achse des Bechers (13) oder anderen Behälters ist.
4. Becher oder andere Behälter nach einem der vorhergehenden Ansprüche, bei welchem
die Dikke der Stapeleinrichtungen (4, 5) und der Boden (3) nirgendwo weniger als im
wesentlichen 1,15 mm beträgt.
5. Verfahren zur Herstellung eines Bechers oder anderen Behälters nach einem der vorhergehenden
Ansprüche, bei welchem ein Plastikblattmaterial in einer weiblichen Gußform druckgeformt
wird, welche Kanten mit Radien hat, die im Querschnitt 0,25 mm nicht überschreiten.
6. Verfahren nach Anspruch 5, bei welchem der Teil der Gußform, welcher die nach oben
weisende Schulter formt, unter einem Winkel im Bereich von 5° bis 10° zu einer Ebene
geneigt ist, die senkrecht zur Achse des Bechers (13) oder anderen Behälters ist.
1. Gobelet ou autre récipient, pouvant être emboîté, comprenant un fond (3), une paroi
latérale (2), et des moyens d'empilement comportant un épaulement circonférenciel
doté d'une surface interne (5) tournée vers le haut, inclinée en direction descendante
vers l'extérieur et se terminant par un coin convexe (9) à angle aigu, cette surface
étant soit continue, soit interrompue pour former des créneaux, de sorte que lorsque
plusieurs gobelets (11, 12, 13) ou autres récipients, identiques, sont assemblés en
une pile verticale, le coin (9) du gobelet (11B, 12B, 13B) ou autre récipient réalise
alors. un contact localisé avec la surface d'empilement du gobelet (11A, 12A, 13A)
ou autre récipient se trouvant au-dessus, le contact entre ce coin (9) et la surface
d'empilement se situant à distance de son bord (10), caractérisé en ce qu'une pluralité
de becs (14) circonférencielle- ment espacés, formant saillie vers l'extérieur, ayant
des bases inclinées en direction descendante vers l'extérieur, sont inclus autour
des moyens d'empilement et sont agencés de manière que, lorsque les gobelets (13A)
ou autres récipients sont emboîtés, les becs (14) sur le gobelet ou récipient supérieur
(13A) soient très proches, ou au contact, de l'intérieur de la paroi latérale (2)
du gobelet (13B) immédiatement en dessous.
2. Gobelet ou autre récipient selon la revendication 1, réalisé en polystyrène à grande
résistance aux chocs, en polystyrène d'autres qualités, en polypropylène ou en chlorure
de polyvinyle.
3. Gobelet ou autre récipient selon la revendication 1 ou 2, dans lequel l'épaulement
intérieur (5), tourné vers le haut, est incliné selon un angle compris entre 5° et
10° par rapport à un plan normal à l'axe du gobelet (13) ou autre récipient.
4. Gobelet ou autre récipient selon l'une quelconque des revendications précédentes,
dans lequel l'épaisseur des moyens d'empilement (4, 5) et du fond (3) n'est en aucun
endroit sensiblement inférieure à 0,15 mm.
5. Méthode de fabrication d'un gobelet ou autre récipient selon l'une quelconque des
revendications précédentes, dans laquelle un matériau en feuille de matière plastique
est formé sous pression dans un moule femelle ayant des coins qui, considérés en coupe,
ont des rayons n'excédant pas 0,25 mm.
6. Méthode selon la revendication 5, dans laquelle la partie du moule qui forme l'épaulement
(5) tourné vers le haut est inclinée d'un angle compris dans une plage de 5° à 10°
par rapport à un plan normal à l'axe du gobelet (13) ou autre récipient.