Abstract:
The present invention relates to a bag including:
       two generally parallel sheets;   matching closing profiles fixed on these sheets;   a slider for actuating the profiles, this slider comprising flanks each inner surface of which bears a boss.       
 
     This bag is remarkable by the fact that said sheets include on their outer faces, and outside said slider, abutment means capable of immobilizing said sheets relatively to said slider along a direction generally perpendicular to the displacement axis (X-X′) of the slider.

Description:
[0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 12/275,033, filed Nov. 20, 2008, which claims priority to French Patent Application No. 0708161, filed Nov. 21, 2007, both of which are incorporated herein by reference in their entirety. 
     
    
       [0002]    The present invention relates to the field of bags comprising matching closing profiles respectively actuated upon opening and closing by a slider. 
         [0003]    These bags have already been very helpful. Indeed, the sliders facilitate the opening and closing of the bags, so that their presence is strongly appreciated by elderly or partially sighted persons. 
         [0004]    In the past, one was confronted with a sealing defect of these bags. In particular, most of these bags did not have a total seal in the position for closing the profiles. This sealing defect was due to the fact that the profiles remain separate in front of the slider. 
         [0005]    Now, a perfect seal is required in many applications, notably, but without any limitation, for bags used for freezing food products. 
         [0006]    In document WO-A-99/65353, a bag structure is described with which this sealing defect may be overcome. 
         [0007]    Thus, in a particular embodiment, a bag is described, which includes:
       two generally parallel sheets forming its main walls,   matching closing profiles respectively fixed on these sheets,   a slider for actuating the profiles upon closing and opening, this slider comprising flanks, each inner surface of which bears a boss directed towards the opposite flanks, so that the sheets forming the main walls converge towards each other, said profiles towards said bosses.       
 
         [0011]    The sealing problem according to the aforementioned document is solved by the fact that parallel to the profiles, between the sheets and at the mouth of the bag, additional raised relief means are provided, positioned on the inside of the closing profiles, designed to provide a seal by forming a barrier between the sheets in the closure position of the bag, these additional means being adapted so as to be urged towards their sealing position by the slider when the latter is moved towards the closure position of the bag. 
         [0012]    Therefore, the relative seal provided by the matching profiles is completed by that provided by the additional raised relief means. 
         [0013]    Such a structure generally gives satisfaction. However, it is perfectible insofar that it is necessary to make sure that the slider is properly positioned relatively to the additional raised relief means, so as to make sure that the sheets are nipped at a distance allowing good contact of these additional means. 
         [0014]    In other words, situations occur in which either one of both sheets of the bag undergoes a slight translation in a direction perpendicular to the displacement axis of the slider, so that the aforementioned additional means are no longer facing the other sheet. It is easily understood that a sealing defect then results from this. 
         [0015]    Even in the absence of said additional means, the slight translation poses a problem. 
         [0016]    The present invention is therefore directed to solving this difficulty. 
         [0017]    A secondary object of the invention is to fulfill this purpose, without changing the general structure of the aforementioned bag. 
         [0018]    The invention therefore relates to a bag including:
       two generally parallel sheets forming main walls of the bag,   matching closing profiles respectively fixed on these sheets; and   a slider for actuating the profiles upon closing and opening,   said slider comprises opposing flanks,   each inner surface of the opposite flanks bears a boss directed towards the other opposite flank such that the sheets forming the main walls of the bag converge towards each other,   the two generally parallel sheets comprise, on their respective outer faces and outside said slider, a bulge protruding from a surface of each of said sheets and extending parallel to a displacement axis of the slider   the bulge is adjacent to the slider such that the bulges immobilize the two generally parallel sheets relative to said slider along a direction generally perpendicular to the displacement axis of the slider,   the bag further comprises, inside said slider, additional raised relief sealing bulges that run parallel to said profiles, on the side of said sheets which face each other,   the additional raised relief bulges are positioned on a side of the closing profiles that is inside the bag when in a closure position,   the additional raised relief bulges are designed to provide a seal by forming a barrier between the sheets in the closure position of the bag, and   said additional raised relief bulges are configured so as to be urged towards a sealing position by the slider when the slider is moved so as to cause the closure position of the bag,   the distance between said bosses is smaller than the cumulated thickness of said relief sealing bulges,   the distance between said bulges and said additional raised relief bulges is slightly higher than the width of said bosses.       
 
         [0032]    By these abutment means, proper positioning of the sheets and of the slider is performed so as to achieve proper nipping of the sheets. 
         [0033]    According to other advantageous but non-limiting features:
       the bag further comprises additional abutment bulges located on said sheets in an inner space of the slider;   said bulge of each sheet is continuous;   said bulge of each sheet is formed with a series of discontinuous sections, and a largest interval between two neighboring discontinuous sections is smaller than a longitudinal dimension of said slider;   said bulge of each sheet is made with its respective sheet in a same material;   said bulge of each sheet is a component added to its respective sheet.       
 
         [0039]    Other features and advantages of the present invention will become apparent upon reading the following detailed description of certain preferred embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0040]    This description will be made with reference to the appended drawings wherein: 
           [0041]      FIG. 1  is a schematic sectional view of an embodiment of the bag of the invention; 
           [0042]      FIGS. 2 and 3  are detailed and enlarged views of the bag structure of  FIG. 1 ; 
           [0043]      FIGS. 4 ,  5  and  6  are partial front views of a bag according to the invention, illustrating several embodiments of the abutment means. 
       
    
    
     DETAILED DESCRIPTION 
       [0044]    The bag illustrated in  FIG. 1  has a structure generally known from document WO-A-99/65353 which was commented above. 
         [0045]    This bag  1  includes a mouth  10  and a bottom  11 . It consists of two main plastic sheets referenced as  12  and  13 . 
         [0046]    These sheets are connected together at the bottom  11 . In the embodiment illustrated here, both sheets are integral with each other from the start. However, in an embodiment not shown, both of these sheets may be initially separate, and then superposed and attached to each other when manufacturing the bag. 
         [0047]    At the mouth  10 , both sheets  12  and  13  are provided with matching closing profiles  2  and  3 . 
         [0048]    These profiles may be the object of many embodiments. The invention is not limited to the specified embodiment illustrated in  FIG. 1 . 
         [0049]    In the case illustrated here, the profiles  2  and  3  are of the male and female type respectively, as this is well-known to one skilled in the art. However, the invention may apply to other types of profiles, notably of the type with matching hooks. 
         [0050]    In the embodiment of  FIG. 1 , the profiles  2  and  3  are made by extrusion with the sheets  12  and  13  which form the bag. 
         [0051]    However, in an alternative embodiment not shown, these matching profiles may be borne on supporting webs added onto the sheets  12  and  13 , for example by hot welding or adhesive bonding. 
         [0052]    As mentioned above, the bag further includes a slider  5  adapted for actuating the profiles  2  and  3  upon closing and opening. 
         [0053]    This slider may be the object of many standard embodiments. A typical slider example is described in document EP-A-0 479 661. In the embodiment shown here, the slider made in plastic material, includes two side wings  51  and  52  (or flanks), connected together at a base  50  and which define with an elongated central sole  55 , two convergent passageways for the engageable matching closing profiles  2  and  3 . 
         [0054]    Thus, when the direction of relative displacement of the slider  5  with respect to the closing profiles  2  and  3  tends to displace the slider by forcing engagement of the profiles, the bag is closed. When the slider  5  is displaced in the reverse direction, the bag is opened. 
         [0055]    It will be noted that the base of the flanks  51  and  52  of the slider extends inwards through bosses  53  and  54  directed towards each other. 
         [0056]    Because of the presence of the bosses, the sheets forming the main walls of the bag converge towards each other, profiles  2  and  3  towards (in the direction of) these bosses. 
         [0057]    In other words, from the profiles, the main walls converge towards in each other in the direction of the inner space of the bag. 
         [0058]    The bag moreover includes additional raised relief means  4  which are designed in order to provide the seal by forming a barrier between the sheets  12  and  13 , in the closure position of the bag. They are positioned inside the closing profiles. 
         [0059]    In other words, these means  4  are placed on the inner face of each sheet, facing the flanks  51  and  52  of the slider  5  so as to be urged towards their sealing position by the slider when the latter is moved towards the sealing position. 
         [0060]    More specifically, these means  4  each consists of bulge of plastic material which extends parallel to the displacement axis X-X′ of the slider. 
         [0061]    To provide the seal, the bulges extend exactly facing each other. 
         [0062]    But, as discussed above, it occurs that one of the sheets  12  and  13  of the bag undergoes a slight translation perpendicular to the displacement direction of the slider, so that the bulges  4  are no longer strictly facing each other. 
         [0063]    A sealing defect then results from this. 
         [0064]    This is the reason why the sheets  12  and  13  include on their outer face, adjacent to the bosses  53  and  54  of the slider, abutment means  6  capable of immobilizing the sheets  12  and  13  relatively to the slider  5 , along a direction generally perpendicular to the displacement axis X-X′ of the slider, by contact between the bosses  53  and  54  and these abutment means  6 . 
         [0065]    In the embodiment shown in  FIGS. 1-3 , the abutment means consist of a bulge of material which extends all along the transverse stretch of the bag. 
         [0066]    In the embodiment of  FIG. 2 , these are bulges added on the sheets  12  and  13 , whereas in  FIG. 3 , these bulges are extruded with the sheets  12  and  13 . 
         [0067]    By the presence of these abutment means, the positioning of the sheets relatively to the slider is &lt;&lt;blocked&gt;&gt; so that the additional sealing means  4  are perfectly facing each other and completely provide their sealing function. As clearly shown on  FIG. 1 , the distance d 1  between said bosses  53  and  54  is smaller than the cumulated thickness d 2  of said relief sealing bulges  4 . 
         [0068]    Consequently, said both sheets are “pinced” between said bosses  53  and  54 , and cannot move because of the abutment of bulges  6  against the slider  5 . 
         [0069]    The result is that said relief sealing bulges always face each other. 
         [0070]    Furthermore, and as also shown on  FIG. 1 , the distance e 1  between the bulges  6  and said relief sealing bulges is slightly higher than the thickness e 2  of said bosses  53  and  54 . 
         [0071]    This features also permits to maintain said relief sealing bulges in a stable position, facing each other. 
         [0072]    Moreover, because of the presence of the profiles  2  and  3  in the sheets  12  and  13 , these regions of the bag are rigid or not very deformable. Now, the presence of the abutment means  6  contributes to bringing the sheets  12  and  13  closer to each other. 
         [0073]    Different embodiments of the abutment means are illustrated in  FIGS. 4-6 . In order to facilitate reading of these figures, the abutment means  6  are illustrated slightly separate from the slider  5 . However, in practice, they are positioned very close to this slider. 
         [0074]    In the embodiment of  FIG. 4 , the abutment means consist of a continuous bulge which extends parallel to the displacement axis X-X′ of the slider. 
         [0075]    In the embodiment illustrated in  FIG. 5 , this bulge, parallel to the X-X′ axis is discontinuous and formed with a series of sections, the largest interval l 2  between two neighboring sections being smaller than the longitudinal dimension l 1  of the slider  5 . 
         [0076]    Thus, regardless of the positioning of the slider, the latter is always located facing at least one profile. 
         [0077]    Finally, in the embodiment of  FIG. 6 , the bulge  6  is also discontinuous and consists of a series of sections limited to their simplest expression, which means that they consist of points. 
         [0078]    There again, the largest interval l 3  between two neighboring profiles is smaller than the longitudinal dimension l 1  of the slider. 
         [0079]    The sheets, closing profiles, additional sealing means and abutment means may be made in any suitable plastic material known to one skilled in the art. 
         [0080]    Preferably, this is a polyolefin, very advantageously low or high density polyethylene, or even polypropylene. 
         [0081]    In the embodiments illustrated in the appended figures, the abutment means  6  are located outside the slider  5 . 
         [0082]    However, provision of additional, identical or similar abutment means on the side of the inner space of the slider, on the sheets, may be contemplated. Thus, the bosses  53  and  54  are framed by the abutment means on their opposite sides.