Abstract:
a tamper-resistant sealing system between a container body and the lid, both obtained by a thermoforming process, in which said contained body and said lid have a respective curved or grooved edge structured to fitted one to another, each curved or grooved edge including a top portion and an outer wall portion, said outer wall portion of said lid presenting a pair of weakening lines defining a breakable and removable strip there between and constraint means is provided between said outer wall portion of said container body and said lid.

Description:
FILED OF THE INVENTION  
       [0001]     The present invention relates to a tamper-resistant sealing system between a container body and a lid both obtained by a thermoforming process.  
         [0002]     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.  
         [0003]     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.  
       SUMMARY OF THE INVENTION  
       [0004]     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.  
         [0005]     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.  
         [0006]     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.  
         [0007]     Advantageously, said constraint means is located at the outer free edges of said portions of outer wall. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     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:  
         [0009]      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;  
         [0010]      FIG. 2  is a perspective view of the container in  FIG. 1  with the lid snap-engaged thereon in a closed position;  
         [0011]      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;  
         [0012]      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;  
         [0013]      FIG. 5  illustrates a detail of  FIG. 4  on an enlarged scale, with a length of strip torn away;  
         [0014]      FIG. 6  shows a detail of the container body of  FIG. 1  and its lid lifted therefrom after complete tearing of the strip;  
         [0015]      FIG. 7  shows a container-lid sealing system according to the present invention shaped as a parallelepiped basin;  
         [0016]      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;  
         [0017]      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;  
         [0018]      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;  
         [0019]      FIG. 11  is a partial cross-sectional view of a fourth embodiment, which is a variation with respect to the embodiment of  FIG. 10 ;  
         [0020]      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;  
         [0021]      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 ;  
         [0022]     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. 
     
    
       [0023]     In the accompanying drawings the same or similar parts or components have been indicated with the same reference numerals.  
       DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]     With reference first to FIGS.  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.  
         [0025]     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 FIGS.  8  to  17  of the drawings.  
         [0026]     In the embodiment shown in  FIG. 8 , each edge  3  and  4  is an extension of a slightly flared wall  1   a  and  2   a  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  1   a  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, is an outwardly projecting flange.  
         [0027]     Downwards projecting portion  8  of the edge  3  comprises in sequence from the transverse top portion  7 , a substantially vertical upper length  8   a , a short and radiused length  8   b  extending inwards and delimiting an inner undercut shoulder  10 , an intermediate length  8   c , which is frustoconical in shape as it extends flared downwards, and a lower length  8   d  adjacent to the end rim portion  9 .  
         [0028]     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  2   a  extending upwards from the lower undercut radiused portion  11 , a top flat portion  12  transversely extending outwards from side portion  2   a , 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 .  
         [0029]     Outer portion  13  of edge  4  includes, in sequence, an upper wall length  13   a  extending, in use, substantially vertical, a short inwards radiused wall portion  13   b  designed to engage with the outer undercut shoulder  10  delimited in the wall portion  8 , an intermediate wall length  13   c , extending slightly flared, and a lower length  13   d  designed to abut, in use, against the lower length  8   d.    
         [0030]     Length  13   c , and possibly lengths  13   c  and  13   b  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.  
         [0031]     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 ).  
         [0032]     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  13   c  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  8  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.  
         [0033]     Snap-engagement between length  13   b  and shoulder  10 , if the weakening line  15  is also obtained along length  13   c , further comprises a sealing or tight annular zone against liquid or gas leakages from inside the container body  1 .  
         [0034]      FIG. 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 .  
         [0035]     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.  
         [0036]      FIG. 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  2   a.    
         [0037]      FIG. 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 .  
         [0038]     The embodiment shown in  FIG. 12  is similar to that illustrated in  FIG. 9 , except the inner walls  6  and  2   a  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  6   b , an intermediate outwardly radiused length  6   c , and an upper undercut length  6   d  which is connected to top portion  7 . Inner wall  2   a  of the lid comprises a lower undercut length  2   b  radiused with radiused portion  11 , an intermediate outwardly projecting length  2   a  which is radiused at the top thereof with an upper length  2   d  connected to top portion  12 .  
         [0039]     When lid  2  is fitted onto container body  1 , between lengths  6   d  and  6   b  of container body edge and lengths  2   d  and  2   b , respectively, of lid edge two tight or sealing peripheral zones are provided, thereby forming a so-called two sealing point closing system.  
         [0040]     The embodiment illustrated in  FIGS. 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 .  
         [0041]     The embodiment illustrated in  FIG. 15  has edges  3  and  4  having walls  6  and  2   a  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 .  
         [0042]     With reference to  FIG. 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 .  
         [0043]      FIG. 17  illustrates an embodiment with edges  3  and  4  having inner walls  6  and  2   a , respectively, and outer walls  8  and  13  as in the embodiments of  FIGS. 12, 15 , and  16 .  
         [0044]     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.  
         [0045]     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 .  
         [0046]     The above described tamper-resistant sealing system is susceptible to numerous modifications and variations within the scope as defined by the claims.