EP1559656A1

EP1559656A1 - Container and lid with tear-away tamper resistant sealing strip

Info

Publication number: EP1559656A1
Application number: EP05001764A
Authority: EP
Inventors: Pietro Padovani
Original assignee: Isap OMV Group SpA
Current assignee: Isap OMV Group SpA
Priority date: 2004-01-28
Filing date: 2005-01-28
Publication date: 2005-08-03
Also published as: US20050189353A1; ITVR20040011A1

Abstract

A tamper-resistant sealing system between a container body (2) and a lid (2), both obtained by a thermoforming process, in which said contained body (1) and said lid (2) have a respective curved or grooved edge (3, 4) structured to fitted one to another, each curved or grooved edge (3, 4) including a top portion (7, 12) and an outer wall portion (8, 13), said outer wall portion (13) of said lid (2) presenting a pair of weakening lines (15, 16) defining a breakable and removable strip (S) therebetween and constraint means (G, 18) is provided between said outer wall portion (8, 13) of said container body (1) and said lid (2).

Description

The present invention relates to a tamper-resistant sealing system between a container body and a lid both obtained by a thermoforming process.
A number of tamper-resistant sealing systems between a container body and its lid have already been proposed, which are obtained by an injection moulding process. Injection systems use quite different techniques than those involved in a thermoforming process, in which, as it is known, a continuous sheet or tape of thermoformable material is employed.
The need exists nevertheless in the market of having at disposal tamper-resistant sealing systems for containers obtained by a thermoforming process and so structured as to contain in a leakproof way food products or medicaments, both solid and liquid, in view of guaranteeing the integrity of the product contained therein and thus preventing tampering, contaminations, or deteriorations of the content.
One object of the present invention is to provide a tamper-resistant sealing system between a thermoformed container body, e.g. a small basin, glass, vase or the like, and a thermoformed lid, that can be used both to prevent losses or leakages from the container and to provide a clear and safe evidence against possible tampering, or even against attempts to break the sealing.
Another object of the present invention is to provide a very efficient tamper-resistant sealing system easy to use and of almost unlimited duration particularly suitable for keeping food products and/or medicaments.
These and other object, that will better appear below, are achieved by a tamper-resistant sealing system between a container body and a lid, each obtained through a thermoforming process, in which said container body and said lid have a respective curved or grooved edge so structured as to engage with one another, each curved or grooved edge including a top portion and an outer wall portion, said outer wall portion of said lid comprising a pair of weakening lines which delimit a breakable and removable strip therebetween, characterized in that it comprises constraint means between said portion of outer wall of said container body and said lid.
Advantageously, said constraint means is located at the outer free edges of said portions of outer wall.
Further features and advantages of the present invention will better appear from the following description of preferred embodiments thereof, given by way of non-limiting examples of carrying out the invention, with reference to the accompanying drawings, in which:
Fig. 1 is a perspective view of a circular, slightly conical container and of a lid in an open position that can be arranged onto the container, illustrating the tamper-resistant sealing system according to the present invention;
Fig. 2 is a perspective view of the container in Fig. 1 with the lid snap-engaged thereon in a closed position;
Fig. 3 is a perspective view of a container ellipsoidal or oval in plant view, closed by a lid provided with a sealing system according to the present invention;
Fig. 4 shows a detail of the countersunk portion of the lid outer wall on an enlarged scale, where a portion of a strip length is provided with a grip tab for strip tearing;
Fig. 5 illustrates a detail of Fig. 4 on an enlarged scale, with a length of strip torn away;
Fig. 6 shows a detail of the container body of Fig. 1 and its lid lifted therefrom after complete tearing of the strip;
Fig. 7 shows a container-lid sealing system according to the present invention shaped as a parallelepiped basin;
Fig. 8 illustrates a partial cross-sectional view of a portion of a tamper-resistant sealing system according to a first embodiment of the invention with free edges of the outer wall portions welded or glued to one another;
Fig. 9 is a partial cross-sectional view similar to that of Fig. 8, illustrating another embodiment of a tamper-resistant sealing system according to the present invention, in which the edge of the outer wall portion of the lid is snap-engaged with a notch of the respective edge of the outer wall portion of the container body and inner wall portions of both the container body and the lid are in abutting engagement one against the other;
Fig. 10 is a partial cross-sectional view illustrating a third embodiment of the tamper-resistant sealing system according to the present invention, similar to that of Fig. 9, but without inner wall portion of the lid;
Fig. 11 is a partial cross-sectional view of a fourth embodiment, which is a variation with respect to the embodiment of Fig. 10;
Fig. 12 shows a partial cross-sectional view similar to that of Fig. 9, which illustrates a fifth embodiment of the tamper-resistant sealing system according to the present invention, in which an inner wall portion of both the container body and the lid is provided in mutual snap-engagement;
Figs. 13 and 14 each show a partial cross-sectional view illustrating, respectively, the lid a short time before to be forced to snap-engage with the container body, and the lid completely snap-fitted into a closed position on the container body, wherein the outer wall portion of the container body has a negative inclination with respect to the vertical according to a variation of the embodiment shown in Fig. 12;
Figs. 15 to 17 show a number of partial cross-sectional views of embodiments of the present invention, with container body and lid both having inner and outer wall portions in mutual snap engagement and outer edges of the respective outer wall portions constrained to one another.
In the accompanying drawings the same or similar parts or components have been indicated with the same reference numerals.
With reference first to Figures 1 to 7, it will be noted that a tamper-resistant sealing system according to the present invention, between a thermoformed container body 1, either circular or ellipsoidal (Figs. 1 to 6) or square or polygonal (Fig. 7) in cross section, e.g. a small basin, glass, vase and the like, and a thermoformed lid designed to be tight arranged onto the container body comprises a number of specific coupling arrangements of the upper edge of the container 1 and of the peripheral edge of its lid 2, such arrangements being specifically obtained by a thermoforming process of thermoformable materials.
Container body 1 and lid 2 have a respective an uninterrupted curled edge 3 and 4 so shaped as to permit reciprocal snap engagement with one another. Specific configurations of the container body edges 3 and the lid edge 4 are better illustrated in Figures 8 to 17 of the drawings.
In the embodiment shown in Figure 8, each edge 3 and 4 is an extension of a slightly flared wall 1 a and 2a of the container 1 and the lid 2, respectively. More particularly, the edge 3 of the container body (imagined arranged in position of use, i.e. with its edge 3 facing upwards), from its wall 1a comprises, in sequence, a flanged portion 5, extending outwards from the top portion of the side wall 1 a, a slightly flared portion 6, which is radiused with the flanged portion 5 and extends upwards from the flanged portion 5, a top transverse portion 7, which is externally flat and extends projecting outwards, a downwards projecting portion 8 spaced apart from the flared portion 6, and an end rim portion 9, which, in this embodiment, isan outwardly projecting flange.
Downwards projecting portion 8 of the edge 3 comprises in sequence from the transverse top portion 7, a substantially vertical upper length 8a, a short and radiused length 8b extending inwards and delimiting an inner undercut shoulder 10, an intermediate length 8c, which is frustoconical in shape as it extends flared downwards, and a lower length 8d adjacent to the end rim portion 9.
Edge 4 of the lid 2 (also imagined in position of use with its edge 4 facing upwards) respectively comprises, in sequence, a radiused portion 11, the slightly flared wall portion 2a extending upwards from the lower undercut radiused portion 11, a top flat portion 12 transversely extending outwards from side portion 2a, an outer portion 13 extending downwards from top portion 12, and an end rim portion 14, which in this embodiment is shaped as an outwardly projecting flange designed to rest on the rim portion 9.
Outer portion 13 of edge 4 includes, in sequence, an upper wall length 13a extending, in use, substantially vertical, a short inwards radiused wall portion 13b designed to engage with the outer undercut shoulder 10 delimited in the wall portion 8, an intermediate wall length 13c, extending slightly flared, and a lower length 13d designed to abut, in use, against the lower length 8d.
Length 13c, and possibly lengths 13c and 13b form together an annular peripheral band or strip S delimited by two spaced apart weakening lines 15 and 16, preferably extending parallel to one another. Each weakening line 15 and 16 is defined by a sequence of little intermittent cuts obtained in the wall 13 of the lid edge, such cuts being obtained through any suitable method, e.g. by cutting with a circular crown cutters or by using a suitable laser-perforation technique, known per se in the art.
Strip S is designed to be manually torn away by an operator, preferably by tearing a tab 17 provided for this purpose (Figs. 1 to 5 and 7).
With the above described configuration, once the container 1 has been loaded with the product to be packaged, the lid 2 is preferably automatically applied thereon, first allowing portion 13c to snap-engage with the undercut shoulder 10 and then fixing them together using any suitable system, e.g. a bonding agent 18 or through ultrasound welding. In its closed position, lid 2 cannot be taken off or removed without tearing strip S off, which thus constitutes a clear witness whether the container has been opened, or without otherwise considerably deforming container 1 or lid 2, or both.
Snap-engagement between length 13b and shoulder 10, if the weakening line 15 is also obtained along length 13c, further comprises a sealing or tight annular zone against liquid or gas leakages from inside the container body 1.
Figure 9 illustrates an embodiment, in which outer portions, respectively 8 and 13, of the edge 3 of the container body 1 and of the edge 4 of the lid 2 extend, in use, substantially parallel to one another, whereas rim portion 9 is shaped as an upwards projecting curl, thereby delimitating a receiving groove G for the flanged rim 14 of the outer portion 13.
Preferably, curled rim 9 terminates with an enlargement 19 delimiting, at the rim head, an annular peripheral inclined-plane surface 20 inclined inwardly the receiving groove G and an undercut portion 21. Thus, groove G has both an inclined surface 20, which provides an invitation for flanged rim 14 to snap-fit into the groove G, and the undercut portion 21, which prevents the flanged rim 14 from coming out of the groove, once it has entered it.
Figure 10 shows an embodiment in which edge 3 of the container body 1 is structured as the that in Fig. 8, but terminates with a curled portion 9 as in the embodiment of Fig. 9, whereas lid edge 4 is structured as that of Fig. 8, but can be snap-engaged into groove G of the curled portion 9. Nevertheless, lid 2 is plane at the top thereof, i.e. provided with an inner wall 2a.
Figure 11 shows an embodiment similar to that of Fig. 10, but in which lid 2 has one or more peripheral reinforcement or stiffening ribs 22 and between the top portion 7 of the container body 1 and the lid a sheath 23 of any suitable type is provided, e.g. comprising a plurality of layers, among which one of metal sheet, e.g. of aluminium or aluminium alloy, and another of paper or plasticized paperboard material. As it is standard practice in the art, sheath 23 is welded, or glued, or otherwise tight fixed to the top portion 7 of the container, after the latter has been loaded with a liquid or semi-liquid product, such as yogurt, jam and the like. Lid 2 is fitted onto sheath 23.
The embodiment shown in Fig. 12 is similar to that illustrated in Fig. 9, except the inner walls 6 and 2a of container 1 and lid 2, respectively, are not rectilinear in a cross-sectional view. More particularly, inner wall 6 comprises, in sequence, from flanged portion 5, an inner undercut wall length 6b, an intermediate outwardly radiused length 6c, and an upper undercut length 6d which is conneced to top portion 7. Inner wall 2a of the lid comprises a lower undercut length 2b radiused with radiused portion 11, an intermediate outwardly projecting length 2a which is radiused at the top thereof with an upper length 2d connected to top portion 12.
When lid 2 is fitted onto container body 1, between lengths 6d and 6b of container body edge and lengths 2d and 2b, respectively, of lid edge two tight or sealing peripheral zones are provided, thereby forming a so-called two sealing point closing system.
The embodiment illustrated in Figures 13 and 14 is similar to that of Fig. 12, except, as better seen in Fig. 13 illustrating lid 2 while being fitted onto the container body 1, outer wall portions 8 of the container edge and 13 of the lid edge are mutually arranged at a negative angle α designed to provide a higher nerve or elastic loading to the snap-engagement between rim 14 of the lid and the groove G of the container. Moreover, a lower peripheral rib 24 is provided at the end rim portion 9 of the lid body, which is designed to strengthen the overall rim 9.
The embodiment illustrated in Figure 15 has edges 3 and 4 having walls 6 and 2a shaped as those in the embodiment of Fig. 12 and outer walls 8 and 13, respectively, shaped like those in the embodiment of Fig. 8.
With reference to Figure 16, an embodiment similar to that of Fig. 15 is illustrated, except rim portion 9 of the container body is curled and delimits a receiving groove G for flanged rim 14 of the lid. Inner side 25 of groove G is inclined or flared, whereas its outer side 26 extends upwards and inwards to delimit, together with the adjacent outer wall 8 of the container edge, an annular mouth for free passage of flanged rim 14, which, while the lid is being closed, while sliding on the countersunk inner side 25 of groove G, is forced to widen and can no longer come out from the groove, as it is locked by the outer side 26.
Figure 17 illustrates an embodiment with edges 3 and 4 having inner walls 6 and 2a, respectively, and outer walls 8 and 13 as in the embodiments of Figures 12, 15, and 16.
Any attempt to tamper a sealed container 1 is clearly shown by the fact that strip S is entirely or partly torn away, as the only way of removing lid 2 is to tear strip S.
When strip S has been removed, lid 2 can still be used as a removable lid for the container, e.g. in case of partial consumption of food contained in the container 1.
The above described tamper-resistant sealing system is susceptible to numerous modifications and variations within the scope as defined by the claims.

Claims

A tamper-resistant sealing system between a container body (1) and a lid (2), both obtained by a thermoforming process, in which said container body (1) and said lid (2) have a respective curved or grooved edge (3, 4) arranged to engage with one another, each curved or grooved edge (3, 4) including a top portion (7, 12) and an outer wall portion (8, 13), said outer wall portion (13) of said lid (2) having a pair of weakening lines (15, 16) delimiting a breakable and removable strip (S) therebetween, characterized in that it comprises constraint means (G, 18) between said outer wall portions (8, 13) of said contained body (1) and said lid (2).
A system as claimed in claim 1, characterized in that said constraint means comprises fixing means.
A system as claimed in claim 2, characterized in that said fixing means comprises a bonding agent (18).
A system as claimed in claim 2, characterized in that said fixing means comprises a welding.
A system as claimed in any claim 2 to 4, characterized in that said each outer wall portion (8, 13) ends with a respective flanged edge (9, 14) at which said fixing means is provided.
A system as claimed in claim 1 or 2, characterized in that said constraint means comprises a curled end rim portion (9) of said outer wall portion (8) of said edge (3), and an end rim portion (14) of said outer wall portion (13) of said edge (4), said curled end rim portion (9) delimiting at least one peripheral notch (G) arranged to receive and trap said end rim portion (14).
A system as claimed in claim 6, characterized in that said peripheral notch (G) has inner and outer sides, one of which acts as an invitation for said end rim portion (14) to enter said notch.
A system as claimed in claim 6 or 7, characterized in that said end rim portion (24) is flanged.
A system as claimed in any claim 6 to 8, characterized in that said outer wall portion (8) ends with an enlargement (19) delimiting an upper inclined-plane invitation surface (20) , and a lower undercut portion (21) for snap-fitting with said end rim portion (14).
A system as claimed in claim 9, characterized in that said curled end rim portion (9) delimiting said peripheral notch (G) has at least one peripheral stiffening rim (24) extending opposite to said enlargement (19).
A system as claimed in any previous claim, characterized in that said tearable strip (S) comprises a tearing tag (17).
A system as claimed in any previous claim, characterized in that said outer wall portion (8) of said edge (3) of said container body (1) comprises, in sequence, from said transverse top portion (7), an upper substantially vertical length (8a), a short and radiused length (8b) extending inwards and delimiting an outer undercut shoulder (10), a downwards flared intermediate length (8c), and a lower length (8d) adjacent to said end rim portion (9) and, correspondingly, said outer wall (13) of said edge (4) of said lid (2) comprises, in sequence, an upper wall length (13a) extending, in use, substantial vertical, a short inwards radiused wall portion (13b) designed to engage with said outer undercut shoulder (10) delimited in the wall portion (8), an intermediate wall length (13c) extending flared outwards, and a lower length (13d) designed to abut, in use, against said lower length (8d).
A system as claimed in claim 12, characterized in that said lid has an inner wall (2a).
A system as claimed in claim 13, characterized in that said edge (3) of said container body (1) comprises an inner wall (6) including, in sequence, a lower undercut wall length (6b), an intermediate outwardly radiused length (6c), and an upper undercut length (6d) which is connected to said top portion (7) and, correspondingly, said edge (4) of said lid (2) comprises a lower undercut length (2b), a projecting intermediate length (2c), which is radiused upwards with an upper length (2d) connected to said top portion (12).
A system according to claim 14, characterized in that said outer wall portions (8 and 13, respectively) of said edge of said container body (1) and said lid (2) are mutually angled according through a negative angle.