| (19) |
 |
|
(11) |
EP 0 626 317 B1 |
| (12) |
EUROPEAN PATENT SPECIFICATION |
| (45) |
Mention of the grant of the patent: |
|
08.01.1997 Bulletin 1997/02 |
| (22) |
Date of filing: 24.05.1994 |
|
|
| (54) |
Container made of cardboard or the like having a cylindrical shape and an automatic
bottom
Behälter aus Karton od. dgl. mit zylindrischer Form und automatisch auffaltbarem Boden
Récipient un carton ou matière analogue avec une forme cylindrique et fond automatique
|
| (84) |
Designated Contracting States: |
|
BE CH DE ES FR GB GR LI |
| (30) |
Priority: |
25.05.1993 IT MI931076
|
| (43) |
Date of publication of application: |
|
30.11.1994 Bulletin 1994/48 |
| (73) |
Proprietor: CARTOTECNICA BIANCHI SAFFAPACK S.p.A. |
|
20121 Milano (IT) |
|
| (72) |
Inventor: |
|
- Bianchi, Filippo
I-20154 Milano (IT)
|
| (74) |
Representative: Carloni, Franco |
|
c/o Calvani, Salvi & Veronelli S.r.l.,
Piazza Duca d'Aosta, 4 20124 Milano 20124 Milano (IT) |
| (56) |
References cited: :
DE-A- 4 033 947 US-A- 2 189 436
|
FR-A- 2 375 100 US-A- 3 912 331
|
|
| |
|
|
|
|
| |
|
| 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).
|
[0001] The present invention generally relates to containers made of cardboard or the like,
having an automatic bottom and, more particularly, to a container of the above mentioned
kind capable of taking a substantially cylindrical shape during the assembly.
[0002] The containers made of cardboard or the like, having an automatic bottom are already
known. Their very important feature is to have a so-called "automatic bottom" that
is a bottom which is self-forming during their assembly. In order to obtain the automatic
bottom the blank intended to form the container is provided with suitably shaped bottom
tongues having mutual engagement means. These bottom tongues are glued in pairs to
each other and once the longitudinal edges of the blank have been glued therebetween
and the assembly of the container is started by transforming it from a flattened or
bidimensional shape, as it is put on the market, to the final open or tridimensional
shape, the so glued bottom tongues are brought in such a position as to form the bottom
wall of the container and are retained in this final position by the mutual engagement
of the engagement means.
[0003] By means of this system containers having in plan view poligonal shapes, for example
square, rectangular, pentagonal, esagonal shape etc. have been developed.
[0004] DE-A-40 33 947 discloses a packing container corresponding to the container according
to the entering clause of claim 1 formed from a flat blank. In this blank only two
folding lines, which are diametrically opposed when the container is in its final
condition of use, are extending between an upper edge and a lower edge of the side
wall of the container. In this manner the container can be brought in a flat condition.
Projecting from the upper zone of the lower edge are tongues which are foldable about
linear folding lines. These tongues form an automatically closing bottom when a pressure
is exerted on the two folding lines of the side wall of the container. In order to
bring the container in its final condition of use the linear folding lines of the
tongues have a lenght which is only a portion of the tongue width. Furthermore, the
tongues on the side confronting the lower edge have curved lines. In this container
the bottom tongues are attached to the side wall through small segments only and this
can impair the container because the bottom tongues could get detached.
[0005] US-A-2 189 436 discloses a container comprising a collapsible tubular member, quadrantal
flaps integral with the bottom of said tubular member and foldable inwardly into lapped
bottom forming position, tongue and slot connections between diametrically disposed
quadrantal flaps for locking the same together, inwardly foldable webs connecting
portions of the flaps with the tubular member and being folded over the inside of
the flaps when the same are in bottom forming position and an inner bottom fibre board
disk snugly fitting within the tubular member and seated upon the inwardly folded
webs. This container shows the same disadvantage of that remarked for the container
of the DE-A-4033947. Furthermore, the side wall of this container has a plurality
of score lines and not two folding lines only.
[0006] The present invention aims at obviating this drawback by providing a blank for containers
made of cardboard or the like, having a new design. The container according to claim
1 is capable of permitting the assembly of cylindrical containers, the term "cylindrical"
meaning a solid formed by generatrixes starting from points of a directrix formed
by a closed line: circle, ellipse, oval...
[0007] More particularly, the container according to the present invention having generally
a cylindrical shape and an automatically closing bottom obtained from a blank with
bottom tongues having mutually engagement means for automatically closing the bottom
during the formation of the container, said blank comprising a rectangular zone having
only two folding lines perpendicular to the side corresponding to the bottom of the
container in order to allow the container to be put on the market in a flattened shape
and to be opened in its final tridimensional shape upon the use, a glueing edge on
one of the sides perpendicular to the side corresponding to the bottom of the container
and intended to form the lateral wall thereof is characterized in that said blank
further comprises:
a strip projecting from the side of said rectangular zone corresponding to the bottom
of the container and having at least three curved folding lines from each of which
a single one of the tongues intended to form the automatically closing bottom extends
such that the bottom tongues have at least a curved side corresponding to the curve
folding lines, each curved line being curved over its entire length and having an
identical or different radius of curvature according to the cross-section of the cylindrical
container to be formed,
- the strip being intended to be folded along a folding line which separates it from
the rectangular zone of the blank and to be glued thereto.
[0008] This invention will be now described in greater detail in connection with the accompanying
drawings, wherein:
Fig. 1 shows a first blank for obtaining the right circular cylindrical container
having an automatic bottom;
Fig. 2 shows a first mounting step of the container of Fig. 1;
Fig. 3 shows a second mounting step of the container of Fig. 1;
Fig. 4 is a cross-sectional view taken through the blank after the second mounting
step of the container has been accomplished;
Fig. 5 shows the final mounting step of the container of Fig. 1;
Fig. 6 shows a second blank for obtaining the right circular cylindrical container
having the automatic bottom;
Fig. 7 shows a first mounting step of the container of Fig. 6;
Fig. 8 shows a second mounting step of the container of Fig. 6;
Fig. 9 is s cross-sectional view taken through the blank of Fig. 6 after the second
mounting step of the container has been accomplished;
Fig. 10 shows the final mounting step of the container of Fig. 6, looking from the
bottom;
Fig. 11 shows the container of Fig. 10 in a plan view;
Fig. 12 shows a third blank for obtaining an elliptical cylindrical container having
the automatic bottom;
Fig. 13 is a perspective view of the container obtained with the blank of Fig. 12;
Figs. 14 and 15 show the sectional profile of other containers obtained with the blank
according to the present invention.
[0009] Fig. 1 shows a typical blank for obtaining a container having the shape of a right
circular cylinder and provided with tongues, generally designated by T, intended to
form in a manner per se known the automatic bottom. The blank is designated by 1 and
has a zone 2 of rectangular shape intended to form the lateral wall of the container.
This zone is divided in three portions A,B,C by two cross-folding lines 3,4. The rectangular
zone 2 has on one shorter side thereof, in this case on the portion A, a glueing edge
L. Projecting from the upper larger side of the rectangular zone 2 is a strip, generally
designated by D, divided in four segments D1,D2,D3,D4 each of which terminates in
one of the tongues T intended to form in a manner per se known the automatic bottom
of the container and bearing here the reference numbers 5,6,7,8. This strip D is separated
from the rectangular zone 2 by a longitudinal folding line P and the tongues T are
separated from the relevant strip segment D1,D2,D3,D4 by curved folding lines, generally
designated by S and bearing here the reference numbers 9,10,11,12. In this case the
curved folding lines have the shape of an arc of circle and their radius of curvature
correspond to that of the circular cylindrical container to be formed. The folding
lines 9,10,11,12 in this case are four in number and their length corresponds to 1/4
of the blank lenght
l and therefore 1/4 of the container circumference.
[0010] The tongues 5,6,7,8 have a specifical shape adapted to form the engagement means
of the automatic bottom and, in the blank of Fig. 1, these tongues are identical two
by two. In particular, the tongue 5 has the same shape as that of the tongue 7 and
the tongue 6 has the same shape as that of the tongue 8. The tongues 6 and 8 have
substantially a triangular shape, whereas the tongues 5 and 7 have a composite rectilinear
and curvilinear shape. In particular, each of the tongues 5,7 has a triangular tab
13 and 14, respectively and a toothed portion 16. The substantially triangular tabs
13,14 are defined by an inner folding line 15 and have a curved side which has the
same radius of curvature as that of the circular cylindrical container to be formed.
[0011] Fig. 2 shows the first mounting step of the circular cylindrical container with automatic
bottom starting from the blank 1. This step consists in folding the strip segments
D1,D2,D3,D4 along the folding line P against the rectangular zone 2 and in glueing
them thereto by leaving free the tongues 5,6,7,8.
[0012] Fig. 3 shows a second mounting step of the container. This step consists in glueing
the glueing edge L to the opposite outer side of the rectangular zone 2 so as to obtain
a closed element and in glueing the tabs 13,14 to the triangular tongues 6,8 so that
the tabs 13,14 cover exactly the half portion of said triangular tongues, as can be
seen in the cross-section of Fig. 4 wherein the zones marked by crosses designate
the glueings. Once this operation is terminated, the so obtained blank is folded along
the folding lines 3,4 to form the container in the flattened condition, as it is put
on the market.
[0013] Fig. 5 shows the final mounting step of the container. This step consists in opening
the so glued blank by exerting an inwardly directed pressure on the cross-folding
lines 3 and 4. In so doing, the tongues 5,6,7,8 automatically open inwardly until
the toothed portion 16 of the tongues 5,7 engage therebetween, thus retaining the
formed bottom.
[0014] Fig. 6 shows a second typical starting for obtaining a modification of the right
circular cylindrical container provided with six tongues T intended to form in a manner
per se known the automatic bottom. This blank is designated by 21 and has also a rectangular
zone 22 intended to form the lateral wall of the container. This zone is divided also
in three portions A,B,C by two cross-folding lines 23,24. The rectangular zone 22
has on one shorter side thereof, in this case on the portion A, a glueing edge L.
Projecting from the upper larger side of the rectangular zone 22 is a strip D divided
in three segments D1,D2,D3, each of which is provided with the tongues T, bearing
here the reference numbers 25,26,27,28,29,30 intended to form the automatic bottom.
This strip is separated from the rectangular zone 22 by a folding line P.
[0015] In particular, the strip segment D1 has the tongue 25, the strip segment D2 has the
tongues 26,27,28 and the strip segment D3 has the tongues 29 and 30. All the tongues
are separated from the relevant strip segments by curved folding lines S, bearing
here the reference numbers 31,32,33,34,35,36. Here again the curved folding lines
have the shape of an arc of circle and their radius of curvature correspond to that
of the circular cylindrical container to be formed. The folding lines 31-36 in this
case are six in number and their length corresponds to 1/6 of the blank length
l and therefore to 1/6 of the container circumference.
[0016] The tongues 25-30 have a specifical shape adapted to form the automatic bottom and,
also in the blank of Fig. 6, these tongues are identical two by two. In particular,
the tongue 25 has the same shape as that of the tongue 28, the tongue 26 has the same
shape as that of the tongue 29 and the tongue 27 has substantially the same shape
as that of the tongue 30. The tongues 25,28 have substantially a triangular shape
with curved sides and the tongues 26,29 have substantially the shape of a rhombus
with curved sides, divided in two tabs E,F by an inner folding line 37, whereas the
tongue 27 has the shape of a circle,the radius of curvature of which corresponds to
that of the container to be formed and the tongue 30 has the shape of a circle segment.
[0017] Fig. 7 shows the first mounting step of the circular cylindrical container with automatic
bottom starting from the blank 21 of Fig. 6. This step consists in folding the strip
segments D1,D2,D3, along the folding line P against the rectangular zone 22 and in
glueing them thereto by leaving free the bottom tongues 25-30.
[0018] Fig. 8 shows the second mounting step of the container starting from the blank 21
of Fig. 6. This step consists in glueing the edge L to the opposite edge of the rectangular
zone 22 so as to obtain a closed element and in glueing the tongues 25,28 to the tabs
F of the tongues 26,29. Then the circular tongue 27 is folded along the diametral
folding line 38 and the semicircular portion G of this tongue to the tongue 30 having
the shape of a circle segment which now, after the closed element has been formed,
is in front of the circular tongue 27, as can be seen from the cross-section shown
in Fig. 9. Once this operation is terminated, the so obtained blank 21 is folded along
the cross-folding lines 23,24 to form the container in the flattened condition, as
it is put on the market.
[0019] Fig. 10 shows the final mounting step of the container. This step consists in opening
the so glued blank by exerting an inwardly directed pressure on the cross-folding
lines 23 and 24. In so doing, the tongues 26,27 and 29 automatically open and the
tongue 30 overlaps the circular tongue 27 in order to impart the necessary dimensional
stability to the finished container.
[0020] In Fig. 10 the container is viewed from the bottom so as to show the tongues 26 and
29 which overlap the circular tongue 27.
[0021] In Fig. 11 the container is viewed from the top, so as to show the tongue 30 having
the shape of circular segment which overlaps the circular tongue 27.
[0022] In this case the engagement means shown in the blank of Fig. 1 are not provided,
but in their place there are the tongues 27 and 30, which impart the dimensional stability
to the circular cylindric container once it has been open from the flattened condition
to the final tridimensional shape.
[0023] Fig. 12 shows a third typical blank for obtaining a container having an elliptical
cylindrical shape provided, as in the embodiment of Fig. 6, with six tongues T intended
to form in a manner per se known the automatic bottom. This blank is designated by
121 and has also a rectangular zone 122 intended to form the lateral wall of the container.
This zone is divided also in three portions A,B,C by two cross-folding lines 123,124.
The rectangular zone 122 has on one shorter side thereof, in this case on the portion
A, a glueing edge L. Projecting from the upper larger side of the rectangular zone
122 is also a strip D divided in three segments D1,D2,D3, each of which is provided
with the tongues T, bearing here the reference numbers 125, 126,127,128,129,130 and
intended to form the automatic bottom. This strip is separated from the rectangular
zone 122 by a folding line P.
[0024] In particular, the strip segment D1 has the tongue 125, the strip segment D2 has
the tongues 126,127,128 and the strip segment D3 has the tongues 129 and 130. All
the tongues are separated from the relevant strip segments by curved folding lines
S, bearing here the reference numbers 131,132,133, 134, 135, 136, which represent
the six ellipse segments in which the elliptic cylindrical container to be formed
has been divided.
[0025] The tongues 125-130 correspond to the tongues 25-30 of the blank of Fig. 6 and are
intended to form the automatic bottom. As far as the shapes of the tongues are concerned,
they correspond to those of Fig. 6. In particular, the tongue 125 has the same shape
as that of the tongue 128, the tongue 126 has the same shape as that of the tongue
129 and the tongue 127 has substantially the same shape as that of the tongue 130.
The tongues 125,128 have substantially a triangular shape with curved sides and the
tongues 126,129 have substantially the shape of a rhombus with curved sides, divided
in two tabs E,F by an inner folding line 137, whereas the tongue 127 has the shape
of an ellipse, and the tongue 130 has the shape of an ellipse sector.
[0026] The mounting of the container according to Fig. 12 occurs exactly in the same manner
as that of the container of Fig. 6, the sole difference being given by the fact that
the base of the cylinder in this case corresponds to an ellipse and not to a circle.
[0027] In Fig. 13 the elliptical cylindrical container with the formed automatic bottom
is shown in perspective view.
[0028] Of course, although only three embodiments of the present invention have been described,
illustrating a circular cylindrical container formed starting from four and from six
strip segments each having a curved folding line and an elliptical cylindrical container
formed starting from six strip segments each having a curved folding line, it is apparent
that the curved folding lines can be eigth or more in number.
[0029] In Fig. 14 there is diagrammatically shown, for example, the cross-section of an
oval cylindrical container and, if in the strip D also a segment having a straight
folding line is provided, a cylindrical container having a flat wall portion can be
obtained, as illustrated in Fig. 15.
[0030] From the foregoing, it can be seen that by means of the blank according to the present
invention it is possible to obtain a cardboard container or the like having the generic
external shape of a cylinder in the mathematical sense expressed in the introductory
portion of the description and provided with automatic bottom, what it was not possible
to obtain using the blanks provided with tongues for the automatic bottom till now
used.
1. Container made of cardboard or the like having generally a cylindrical shape and an
automatically closing bottom obtained from a blank with bottom tongues (T; 5,6,7,8)
having mutually engagement means for automatically closing the bottom during the formation
of the container, said blank comprising a rectangular zone (2) having only two folding
lines (3,4) perpendicular to the side corresponding to the bottom of the container
in order to allow the container to be put on the market in a flattened shape and to
be opened in its final tridimensional shape upon the use, a glueing edge (L) on one
of the sides perpendicular to the side corresponding to the bottom of the container
and intended to form the lateral wall thereof, characterized in that said blank further
comprises:
a strip (D; D1,D2,D3,D4) projecting from the side of said rectangular zone (2) corresponding
to the bottom of the container and having at least three curved folding lines (S;
9,10,11,12) from each of which a single one of the tongues (T; 5,6,7,8) (T; 5,6,7,8)
intended to form the automatically closing bottom extends such that the bottom tongues
(T; 5,6,7,8) have at least a curved side corresponding to the curve folding lines
(S; 9,10,11,12), each curved line (S; 9,10,11,12) being curved over its entire length
and having an identical or different radius of curvature according to the cross-section
of the cylindrical container to be formed,
- the strip (D; D1,D2,D3,D4) being intended to be folded along a folding line (P)
which separates it from the rectangular zone (2) of the blank (1) and to be glued
thereto,
2. Container according to claim 1, characterized in that said curved folding lines (S)
of the strip (D) are four in number (9,10,11,12) and there are four bottom tongues
(5,6,7,8) extending therefrom, said curved folding lines (9,10,11,12) being in the
form of arc of circle and having the same radius of curvature as that of the container
to be formed.
3. Container according to claim 2, characterized in that the bottom tongues (5,6,7,8)
are identical two by two.
4. Container according to claims 2 and 3, characterized in that a pair of bottom tongues
(6,8) have substantially a triangular shape.
5. Container according to claim 1, characterized in that said curved folding lines (S)
of the strip (D) are six in number (31,32, 33,34,35,36) and there are six bottom tongues
(25,26,27,28,29,30) extending therefrom, said curved folding lines (31,32,33,34,35,36)
being in the form of arc of circle and having the same radius of curvature as that
of the container to be formed.
6. Container according to claim 5, characterized in that four of the bottom tongues (25,26,28,29)
are identical two by two, the bottom tongue (27) has a circular shape and the bottom
tongue (30) has a segment circular shape having the same radius of curvature as that
of the bottom tongue (27) and that of the container to be formed.
7. Container according to claim 1 characterized in that said curved folding lines (S)
of the strip (D) are six in number (131,132, 133,134,135,136) and there are six bottom
tongues (125,126,127, 128,129,130) extending therefrom, said curved folding lines
(131, 132,133,134,135,136) being in the form of ellipse segments.
8. Container according to claim 7, characterized in that four bottom tongues (125,126,128,129)
are identical two by two, the bottom tongue (127) has an elliptical shape and the
bottom tongue (130) has a sector ellipse shape.
9. Container according to claim 1, characterized in that said curved folding lines (S)
of the strip (D) are oval segments.
10. Container according to one of the preceding claims, characterized in that a strip
segment having a straight folding line can be provided.
11. Container according to one of the claims 5-10, characterized in that a pair of bottom
tongues (25,28; 125,128) have substantially a curvilinear triangular shape.
12. Container according to claims 1 and 5-10, characterized in that a pair of bottom tongues
(26,29; 126,129) have substantially a curvilinear rhombic shape.
1. Aus Karton oder dgl. bestehender, im allgemeinen zylinderförmiger und mit einem sich
selbsttätig schließenden Boden versehener Behälter, der aus einem Zuschnitt erhalten
wird, mit Bodenzungen (T; 5,6,7,8), die Mittel für den gegenseitigen Eingriff zum
selbsttätigen Schließen des Bodens während der Bildung des Behälters besitzen, wobei
der Zuschnitt aus einer rechteckigen Zone (2) mit nur zwei Faltlinien (3,4), die zur
Bodenseite des Behälters senkrecht sind, um den Behälter im flachliegenden Zustand
auf den Markt zu bringen und ihn beim Gebrauch in seine räumliche Endgestalt zu öffnen,
einer Klebekante (L) auf einer der zur Behälterbodenseite senkrechten Seiten zur Bildung
der Behälterseitenwand besteht, dadurch gekennzeichnet, daß der Zuschnitt ferner besteht
aus:
- einem Streifen (D; D1,D2,D3,D4), der von der dem Behälterboden entsprechenden Seite
der rechteckigen Zone (2) absteht und mindestens drei gebogene Faltlinien (S; 9,10,11,12)
hat, von denen sich jeweils eine der Zungen (T; 5,6,7,8) zur Bildung des sich selbsttätig
schließenden Bodens erstreckt, so daß
- die Bodenzungen (T; 5,6,7,8) mindestens eine gebogene Seite haben, die den gebogenen
Faltlinien (S; 9,10,11,12) entspricht, wobei jede gebogene Linie (S; 9,10,11,12) über
ihre gesamte Länge gebogen ist und den gleichen Krümmungsradius entsprechend des Querschnitts
des zu bildenden zylinderförmigen Behälters hat,
- wobei der Streifen (D; D1,D2,D3,D4) längs der Faltlinie (P), die ihn von der rechteckigen
Zone (2) des Zuschnitts (1) trennt, gefaltet und an diese Zone geklebt wird.
2. Behälter nach Anspruch 1, dadurch gekennzeichnet, daß die gebogenen Faltlinien (S)
des Streifens (D) vier sind (9,10,11,12) und vier sich davon erstreckende Bodenzungen
(5,6,7,8) vorhanden sind, wobei die gebogenen Faltlinien (9,10,11,12) eine Kreisbogenform
aufweisen und denselben Krümmungsradius wie der des zu bildenden Behälters haben.
3. Behälter nach Anspruch 2, dadurch gekennzeichnet, daß die Bodenzungen (5,6,7,8) paarweise
identisch sind.
4. Behälter nach Anspruch 2 und 3, dadurch gekennzeichnet, daß zwei Bodenzungen (6,8)
im wesentlichen eine Dreiecksform haben.
5. Behälter nach Anspruch 1, dadurch gekennzeichnet, daß die gebogenen Faltlinien (S)
des Streifens (D) sechs sind (31,32,33,34,35,36) und sechs sich davon erstreckende
Bodenzungen (25,26,27,28,29,30) vorhanden sind, wobei die gebogenen Faltlinien (31,32,33,34,35,36)
eine Kreisbogenform aufweisen und denselben Krümmungsradius wie derjenige des zu bildenden
Behälters haben.
6. Behälter nach Anspruch 5, dadurch gekennzeichnet, daß vier der Bodenzungen (25,26,28,29)
paarweise identisch sind, wobei die Bodenzunge (27) kreisförmig ist und die Bodenzunge
(30) die Form eines Kreissektors hat und sie denselben Krümmungsradius wie die Bodenzunge
(27) und derjenige des zu bildenden Behälters haben.
7. Behälter nach Anspruch 1, dadurch gekennzeichnet, daß die gebogenen Faltlinien (S)
des Streifens (D) sechs sind (131,132,133,134,135,136) und sechs sich davon erstreckende
Bodenzungen (125,126,127,128,129,130) vorhanden sind, wobei die gebogenen Faltlinien
(131,132,133,134,135,136) die Form von Ellipsensektoren haben.
8. Behälter nach Anspruch 7, dadurch gekennzeichnet, daß vier Bodenzungen (125,126,128,129)
paarweise identisch sind, die Bodenzunge (127) eine Ellipsenform und die Bodenzunge
(130) die Form eines Ellipsensektors hat.
9. Behälter nach Anspruch 1, dadurch gekennzeichnet, daß die gebogenen Faltlinien (S)
des Streifens (D) ovale Abschnitte sind.
10. Behälter nach irgendeinem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß
ein Streifenabschnitt mit einer geraden Faltlinie vorgesehen werden kann.
11. Behälter nach irgendeinem der Ansprüche 5 - 10, dadurch gekennzeichnet, daß zwei Bodenzungen
(25,28; 125,128) im wesentlichen eine gebogene Dreiecksform haben.
12. Behälter nach Anspruch 1 und nach den Ansprüchen 5 - 10, dadurch gekennzeichnet, daß
zwei Bodenzungen (26,29; 126,129) im wesentlichen eine gebogene Rautenform haben.
1. Récipient en carton ou analogue, ayant une forme globalement cylindrique et un fond
à fermeture automatique, obtenu à partir d'un flan ayant des languettes de fond (T;
5,6,7,8), présentant des moyens d'engagement mutel servant à fermer automatiquement
le fond durant la formation du récipient, ledit flan comprenant une zone rectangulaire
(2) ayant seulement deux lignes de pliage (3,4) perpendiculaires au côté correspondant
au fond du récipient, en vue de permettre au récipient d'être mis sur le marché sous
une forme aplatie et d'être ouvert vers sa forme tridimensionnelle finale lors de
l'utilisation, un bord collant (L) sur l'un des côtés perpendiculaires au côté correspondant
au fond du récipient et destiné à former sa paroi latérale, caractérisé en ce que
ledit flan comprend en outre une bande (D; D1,D2,D3,D4) faisant saillie du côté de
ladite zone rectangulaire (2) qui correspond au fond du récipient et présentant au
moins trois lignes de pliage (S; 9,10,11,12) incurvées, à partir desquelles s'étend
une seule des languettes (T; 5,6,7,8) destinées à former le fond à fermeture automatique,
de manière que les languettes de fond (T; 5,6,7,8) présentent au moins un côté incurvé
correnspondant aux lignes de pliage (S; 9,10,11,12), chaque ligne incurvée (S; 9,10,11,12)
étant incurvée sur toute sa longueur et ayant un rayon d'incurvation identique ou
différent d'après la section transversale du récipient cylindrique à former, la bande
(D; D1,D2,D3,D4) étant destinée à être pliée le long d'une ligne de pliage (P) qui
la sépare de la zone rectangulaire (2) du flan (1) et qui est destinée à être collée
sur cette dernière.
2. Récipient selon la revendication 1, caractérisé en ce que lesdites lignes de pliage
(S) incurvées de la bande (D) sont au nombre de quatre (9,10,11,12) et quatre languettes
de fond (5,6,7,8) s'étendent depuis ces dernières, lesdites lignes de pliage (9,10,11,12)
incurvées se présentant sous la forme d'un arc de cercle et ayant le même rayon d'incurvation
que le récipient à former.
3. Récipient selon la revendication 2, caractérisé en ce que les languettes de fond (5,6,7,8)
sont identiques deux par deux.
4. Récipient selon les revendications 2 et 3, caractérisé en ce qu'un couple de languettes
de fond (6,8) présentent une forme sensiblement triangulaire.
5. Récipient selon la revendication 1, caractérisé en ce que lesdites lignes de pliage
(S) incurvées de la bande (D) sont au nombre de six (31,32,33,34,35,36) et six languettes
de fond (25,26,27,28,29,30) s'étendent depuis ces dernières, lesdites lignes de pliage
(31,32,33,34,35,36) incurvées se présentant sous la forme d'un arc de cercle et ayant
le même rayon d'incurvation que le récipient à former.
6. Récipient selon la revendication 5, caractérisé en ce que quatre des languettes de
fond (25,26,28,29) sont identiques deux par deux, la languette de fond (27) présentant
une forme circulaire et la languette de fond (30) présentant une forme circulaire
de segment ayant le même rayon d'incurvation que la languette de fond (27) et que
le récipient à former.
7. Récipient selon la revendication 1, caractérisé en ce que lesdites lignes de pliage
(S) incurvées de la bande (D) sont au nombre de six (131,132,133,134,135,136) et six
languettes de fond (125,126,127,128,129,130) s'étendent depuis ces dernières, lesdites
lignes de pliage (131,132,133,134,135,136) incurvées se présentant sous la forme de
segments d'ellipse.
8. Récipient selon la revendication 7, caractérisé en ce que quatre languettes de fond
(125,126, 128,129) sont identiques deux par deux, la languette de fond (127) présentant
une forme elliptique et la languette de fond (130) présentant une forme de secteur
d'ellipse.
9. Récipient selon la revendication 1, caractérisé en ce que lesdites lignes de pliage
(S) incurvées de la bande (D) sont des segments de forme ovale.
10. Récipient selon l'une des revendications précédentes, caractérisé en ce qu'un segment
de bande ayant une ligne de pliage droite peut être prévu.
11. Récipient selon l'une des revendications 5 à 10, caractérisé en ce qu'un couple de
languettes de fond (25,28; 125,128) présente une forme sensiblement triangulaire curviligne.
12. Récipient selon les revendications 1 et 5 à 10, caractérisé en ce qu'un couple de
languettes de fond (26,29; 126,129) présente une forme sensiblement rhombique curviligne.