Patent Publication Number: US-2012045151-A1

Title: Tamper-proof packaging bag

Description:
The present invention relates to the field of packaging bags. 
     More precisely, the present invention relates to the field of packaging bags comprising opening/closing means, for example and not limited to the form of complementary profiles. 
     Numerous packaging bags and numerous closing assemblies for this purpose have already been proposed. 
     The majority of closing assemblies known for this purpose comprises two complementary elements, for example of male/female type or pile/hooks type, or even complementary hooks type, supported by respective support webs. 
       FIG. 1  shows the mouth of a reclosable bag known from document FR-A-2628067. 
       FIG. 1  shows the two principal walls  10 ,  20  of the bag at the level of the mouth of the latter.  FIG. 1  also shows a closing assembly  100  comprising two complementary closing elements  110 ,  120  supported by respective webs  112 ,  122  fixed respectively on the walls  10  and  20 . 
     More precisely, the fixing zones of the support webs  112 ,  122  on the films  10  and  20  are referenced  114  and  124 . 
     It is evident from  FIG. 1  that the fixing zone  114  of the support web  112  on the film  10  is not superposed on the male element  110  but offset relative to the latter. By way of variant this could be offset of the fixing zone  124  of the support web  122  on the film  20  relative to the female element  120 . So, the web  112  forming a support to the male element  110  is articulated on the film  10  at the level of the fixing zone  114 . A described in document FR-A-2628067, the preceding arrangement avoids the pressure internal to the bag from being applied to the closing elements  110 ,  120  and tend to separate the latter. In fact, because of the aforementioned arrangement illustrated in  FIG. 1 , separation of the walls  10 ,  20  of the bag (for opening the latter) leads to possible pivoting of the support web  110  at the level of the hinge zone formed by its fixing, without risk of separation of the closing elements  110 ,  120 . 
     The bags matching the arrangement shown in  FIG. 1  have already been well used. Yet, such bags cannot guarantee definitive closing or at least make reopening of the bag sufficiently difficult to ensure its user that its contents cannot accidentally fall out short of forcing the closing assembly. 
     The aim of the present invention therefore is to improve the prior art by proposing novel means for improving known closing assemblies so that they further resist internal and external stresses on the walls of the bag. 
     The above aim is attained within the scope of the present invention by a bag comprising a closing assembly comprising two complementary elements supported by respective support webs integral with a film at the level of a local zone distant from the corresponding closing element to enable articulation of said support webs on the film, said local zones being placed on respective opposite ends of the respective webs on either side of the complementary elements such that one of the articulated webs is directed towards the interior of the bag whereas the other articulated web is directed towards its mouth, characterised in that the support webs have local overthickness at the level of their respective local zone arranged such that a free end of the support webs, which is adjacent to the closing elements, is at a distance from the wall when the closing assembly is at rest. 
     Some preferred but non-limiting aspects of the bag are the following:
         the support webs are formed by material on a wall the bag;   the support webs and the closing assembly are supported by auxiliary support webs applied to and fixed on the walls of the bag;   the two complementary elements of the closing assembly are of male/female type;   the two complementary elements of the closing assembly each comprise complementary hooks whereof the concavity is oriented towards articulation of the web corresponding;   the two complementary elements of the closing assembly comprise complementary male-female closing profiles each fitted at the level of their free ends with hooks adapted to cooperate with the associated profile; and   the closing assembly is double, such that each web comprises two complementary elements.       

    
    
     
       Other characteristics, aims and advantages of the present invention will emerge from the following detailed description, and with respect to the attached diagrams given by way of non-limiting examples, and in which: 
         FIG. 1  previously described schematically illustrates the mouth of a bag conforming to the prior art, 
         FIG. 2   a  illustrates a partial sectional view of a first embodiment of a bag according to the present invention, in a closed position and at rest, 
         FIG. 2   b  illustrates a view similar to  FIG. 2   a  of the same bag, when the walls are stressed on opening, 
         FIG. 3   a  illustrates a partial sectional view of a second embodiment of a bag according to the present invention, in a closed position, 
         FIG. 3   b  illustrates a view similar to  FIG. 3   a  of the same bag, when the walls are stressed on opening, 
         FIG. 4   a  illustrates a partial sectional view of a third embodiment of a bag according to the present invention, in a closed position, 
         FIG. 4   b  illustrates a view similar to  FIG. 4   a  of the same bag, when the walls are stressed on opening, and 
         FIG. 5  illustrates a partial sectional view of a third embodiment of a bag according to the present invention, in a closed position. 
     
    
    
       FIGS. 2 to 5  illustrate a bag according to the present invention, showing two main films  10 ,  20  conventionally comprising per se a bag. The particular modalities of such a bag, in its general structure, will not be described in detail hereinbelow. 
     The walls  10 ,  20  of the bag can form the subject matter of numerous embodiments. 
     They are preferably walls made of thermoplastic material. 
     These walls  10 ,  20  can be mono- or multilayer and mono- or multi-material. In appropriate, they can be a paper support coated in a layer of thermoplastic materials, or even a metallised thermoplastic layer. 
     The bag can be made from a single sheet folded back on itself and welded on three sides, or sheets, for example two sheets welded together at the level of their edges, preferably according to ridges connecting the principal walls. 
       FIGS. 2 to 5  also show a closing assembly  100  comprising at least two complementary closing elements  110 ,  120 . 
     In its general structure, such a closing assembly  100  is known per se and therefore will not be described in detail hereinbelow. It can be closing elements  100  of complementary hooks type ( FIGS. 2   a ,  2   b ), male female ( FIGS. 3 to 5 ), etc. 
     The elements  110 ,  120  of the closing assembly  100  are each supported by a support web  112 ,  120  articulates on a wall  10 ,  20  of the bag. 
     According to the embodiments represented in the figures, the articulated web supports  112 ,  122  are formed by material, more precisely extrusion, on the wall  10  of the bag and connected to the latter in zones referenced  114  and  124  respectively. 
     By way of variant, articulated web supports  112 , could be supported by auxiliary webs applied to the walls  10 ,  20  and fixed thereon by any appropriate means, preferably by thermal welding. 
     It is noted that the joining zones  114 ,  124  between the articulated web supports  112 ,  122  and the walls  10 ,  20  of the bag do not coincide with the joining zones  111 ,  121  of the foot of the element  110 ,  120  on the articulated webs  112 ,  122 . Instead, the local zones  114 ,  124  are placed on respective opposite ends of the webs  112 ,  120  (on the internal faces of the walls  10 ,  20 ), respectively on either side of the complementary elements  110 ,  120 . 
     The local zone  114  of one of the articulated webs  112  is preferably adjacent to the mouth of the bag such that the web  112  is directed towards the interior of the bag, whereas the local zones  124  of the other articulated web  120  is adjacent to the base of the bag such that the web  122  is directed towards its mouth. The articulations of the local zones  114 ,  124  are therefore distant from each other. 
     Due to the above described arrangements, as is evident from  FIGS. 2   b  and  3   b , when the closing elements  110 ,  120  are engaged and stressed apart, the support webs  112 ,  122  pivot at the level of their respective local zone  114 ,  124  and tend to align relative to one another, whether the stressing of the webs  112 ,  122  is internal (due to the bulk of the contents of the bag) or external (due to the action of the user on the mouth, etc.). 
     The opening of the bag is therefore made more difficult, to the extent where the transversal stress exerted by the walls  10 ,  20  is damped by the articulation of the support webs  112 ,  122  which tend in the first instance to move apart the closing elements  110 ,  120  of the walls  10 ,  20 , then secondly play a role of hinge and transform the forces undergone by the closing elements  110 ,  120  into shearing forces. 
     The articulation of the support webs  112 ,  122  on the wall  10 ,  20  of the bag is further improved when at least one of the support webs  112 ,  122  has local overthickness  116 ,  126  at the level of the zone  114 ,  124  respectively, as illustrated in  FIGS. 2   a  to  5 , arranged such that the free end of the support webs  112 ,  122 , which is adjacent to the closing elements  110 ,  120 , is at a distance from the wall  10 ,  20  when the closing assembly  100  is not stressed and is at rest. The principal axis of extension of the support webs  112 ,  122  is therefore offset relative to the wall  10 ,  20 . 
     It is evident that this embodiment of support webs  112 ,  122  boosts the hinge effect linked to their articulation on the walls  10 ,  20 . In fact, it relaxes the free part of the support webs  112 ,  122 , in particular in the zone of the webs  112 ,  122  extending between the local overthickness  116 ,  126  and the closing element  110 ,  120 , the consequence of which is to facilitate the elastic deformation of the support webs  112 ,  122  in this zone and therefore further dampen the effects of internal or external stress. 
     Each of the support webs  112 ,  122  preferably has such local overthickness  116 ,  126  so as to optimise the hinge effect of the closing assembly  100 . 
     According to an embodiment, illustrated in particular in  FIGS. 2   b ,  3   b  and  4   b , resistance to shearing is further improved by using a double closing element  100 , typically two assemblies of complementary hooks  110   a,    110   b,    120   a,    120   b  ( FIGS. 2   a  and  2   b ), two male-female assemblies  110   a,    110   b ,  120   a,    120   b  ( FIGS. 3   a  and  3   b  or  FIGS. 4   a  and  4   b ), or an assembly of complementary hooks associated with a male-female closing assembly (not illustrated in the figures), etc. 
     In fact, using a closing assembly merely creates at the level of contact between the closing means supplementary articulation which undergoes the effect of a lever arm due to the support webs  112 ,  122 . Instead, using at least two closing assemblies  110 ,  120  cancels out this supplementary articulation and rigidifies the closing of the bag, making it even more difficult to open the bag, irrespective of the interior or the exterior. 
     In the variant embodiment of  FIGS. 2   a  and  2   b , the use of complementary hooks  110   a,    110   b,    120   a,    120   b  further reinforces the difficulty of opening the bag when the concavity of the hooks is oriented towards the articulation of the associated support web. In fact, and as is evident in particular in  FIG. 2   a , when the webs are stressed by separation, for example by internal pressure, the hooks  110   a,    110   b,    120   a,    120   b  tend to move horizontally by reinforcing their mutual engagement: the more the hooks are oriented horizontally, the more they hook into each other. 
     The result is a tamper-proof bag in normal conditions of use. 
     As is evident in  FIGS. 4   a  and  4   b , the profiles  110   a,    110   b,    120   a,    120   b  of the male-female assemblies can also be fitted at the level of their ends with hooks so as to better grip the associated profile. Typically, the male profile can have the form of a V-shaped gutter whereof the free ends are curved back towards the interior and are adapted to engage with curved hooks towards the exterior placed on the corresponding free ends of the complementary female profile. 
     Of course, the present invention is not limited to the embodiments which have just been described, but extends to all variants in keeping with its essence. 
     In the attached  FIGS. 3   a  and  3   b,  the articulated web support  112  bears the male closing element  110 . As a variant, the articulated web  112  could bear the female element  120 . 
     De preference, in the cadre of the present invention, the closing assemblies  100  and the articulated webs  112 ,  122  are made of thermoplastic material. 
     Also, as needed, the closing assembly  100  is associated with a cursor facilitating opening/closing. 
     Such a cursor is known per se in its general structure and accordingly will not be described in further detail hereinbelow. It is known that such a cursor generally comprises a sole which bears two lateral fabrics and a central partition defining two non-parallel channels respectively taking up at least the apex of one of the two support webs of the closing or wall assemblies  10 ,  20 , such that according to the direction of displacement of the cursor, the latter stresses the closing assemblies  100  respectively on opening and closing.