Abstract:
A box with tamper-proof lid formed from a single peace of punched and crease-lined cardboard or similar flexible material, of the type having at least one closure panel of high resistance to opening with at least one flap positioned below and in contact with said closure panel when this is closed with a tab projecting therefrom inserted into the box. The tab is folded from the panel about a folding line an at its two ends it presents cuts into which said flaps extend to retain the tab in its closed position.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a box with tamper-proof lid formed from a single piece of punched and crease-lined cardboard or similar flexible material, of the type having at least one closure panel of high resistance to opening with at least one flap positioned below and in contact with said closure panel when this is closed with a tab projecting therefrom inserted into the box, said tab being folded from the panel about a folding line, the two ends of which present cuts into which said flaps extend to retain the tab in its closed position.  
       BACKGROUND OF THE INVENTION  
       [0002]     U.S. Pat. No. 5,207,374, EP-B-0709293 and EP-A-1340684 (all incorporated herein as reference) describe boxes apparently similar to that of the present invention, these boxes having closure panels with high resistance to opening, from said panels there projecting tabs which are inserted into and retained in the respective box when made up and closed, knurled lines being provided, which are broken when the closure panels are opened for the first time, to highlight the fact that the box has already been opened.  
         [0003]     The boxes described in the aforesaid prior patents are very efficient, but they all present the drawback of being able to be opened, using considerable care and patience, without breaking the said knurling, by inserting a thin rigid blade below the closed panel, releasing the box flaps which engage and retain the tabs projecting from said closure panel, then rotating the closure panel (again by means of the thin rigid blade) to open the box lid; this fraudulent box opening operation is very laborious and delicate, but it can be done.  
       BRIEF SUMMARY OF THE INVENTION  
       [0004]     The main object of the present invention is to provide a box similar to those described in the aforesaid prior patents, but which is effectively tamper-proof, in the sense that it cannot be opened without tearing a large part of the box lid.  
         [0005]     A further object is to provide a box which is of low production cost and can be made up and closed in the manner of a common box of similar type.  
         [0006]     These and further objects are attained by a box with tamper-proof lid, comprising: 
        four consecutive main panels and a flap projecting from the fourth main panel on which the first main panel is superposed and glued, the main panels and said flap being separated from each other by longitudinal parallel folding lines,     two closure panels for the two ends of the box and projecting from the ends of at least one of the main panels,     a tab projecting from the ends of at least one of the main panels consecutive to that from which the closure panel projects, the closure panels and said tabs being separated from the main panels by transverse folding line perpendicular to said longitudinal folding lines,     a lip projecting from each closure panel and separated from it by a folding line the two ends of which are both incised by a short cut the width of each closure panel between the folding lines which separate it from the adjacent main panels and from the respective lip being substantially equal to the width of that main panel adjacent to that from which the closure panel projects, wherein in the closure panel there is provided a continuous cut which intersects the folding line and extends with a succession of separate short cuts and a knurling towards the side edges of the said closure panel.        
 
         [0011]     Preferably, said continuous cut, the succession of short cuts and the knurling provided in the closure panel extend along a substantially arc-shaped line.  
         [0012]     Again preferably, in said lips, external to that portion of the closure panel bounded by the continuous cut C-shaped cuts are provided defining appendices projecting from the adjacent closure panel to leave free a corresponding window in the lip when this is folded about the respective folding line which separates it from the closure panel, from the tabs there laterally projecting a hook-shaped tooth which when the box is closed projects through the window left free in the lip by the adjacent appendix to retain this lip inside the box.  
         [0013]     The invention also relates to the sheet in the form of a single piece of punched and crease-lined cardboard or similar flexible material for forming a box having the aforesaid characteristics. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0014]     The structure and characteristics of the box of the invention will be more apparent from the ensuing description of a preferred embodiment thereof given by way of non-limiting example with reference to the accompanying drawings, in which:  
         [0015]     Figures from  1  to  3  represent a punched and crease-lined cardboard sheet shown in plan view and in its successive respective stages of folding to form a box open and lying flat on itself;  
         [0016]      FIG. 4  represents on a considerably enlarged scale one of the two box closure panels, shown flat and integral as it appears in Figures from  1  to  3 ;  
         [0017]      FIG. 5  is a perspective view of a finished and closed box, with its closure panel integral; and  
         [0018]      FIG. 6  shows, on an enlarged scale and seen from a different angle, an end portion of the box of  FIG. 5 , but with its closure panel tampered with, torn and partially lifted upwards. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]     Reference will firstly be made to  FIG. 1 , which shows, spread out in plan view, a piece of punched, crease-lined and knurled cardboard comprising four main panels  1 - 4  and a flap  5  separated from each other by longitudinal parallel folding (crease) lines  6 - 9 . A closure panel  10  projects from each of the two ends of the panel  1 , a tab  11  projecting from each end of the panels  2  and  4 , the closure panels  10  and the tabs  11  being separated from the respective main panels by transverse folding lines, all indicated by the reference numeral  12 .  
         [0020]     From each panel  10  there projects a lip  13  which is separated from the panel by a folding line  14  the two ends of which are both incised by a short cut  15 , the width of each panel  10  between the folding lines  12  and  14  relative thereto being substantially equal to the width of the two main panels  2  and  4 .  
         [0021]     As can be seen in particular from  FIG. 4 , in each of the two lips  13  there are provided two C-shaped cuts which define appendices  19  projecting outwards from the panel  10  when in its flattened position ( FIGS. 1-4 ). When the lips  13  are folded about the respective folding lines  14  (which occurs when the two ends or lids of the made-up box are closed as in  FIG. 5 ), the appendices  19  remain coplanar with the relative panel  10  to leave free within the lips  3  windows into which hook-shaped teeth  20  ( FIGS. 1-3 ) projecting laterally one from each tab  11  are inserted and hooked. When the box is closed, those ends of the tabs  11  close to their folding lines  12  become inserted into the respective cuts  15  provided at the ends of the folding lines  14 , to hence considerably obstruct the opening of the box lid.  
         [0022]     All the aforedescribed structural and functional characteristics are known from U.S. Pat. No. 5,207,374, EP-B-0709293 and EP-A-1340684, incorporated herein for reference: in particular,  FIG. 1  of U.S. Pat. No. 5,207,374,  FIG. 4  of EP-B-0709293 and  FIG. 6  of EP-A-1340684 show how the tabs  11  of the box can interfere with the lip  13  to oppose opening of the lid of the box of which they form part.  
         [0023]     In the cardboard sheet shown in the accompanying figures it can be seen that the panel  1  is provided with a breakable knurling  21  and a semicircular aperture  22  defining an appendix  23  which can be gripped with two fingers of a hand and pulled outwards to break the panel  1  along said knurling: in this manner a lateral lid is obtained, rotatable about the folding line  6 .  
         [0024]     It can also be seen that in the flap  5  there is provided a cut defining an aperture  24  into which the appendix  23  of the rotatable lateral lid can be inserted and retained after it has been opened to extract contained articles from the completed box.  
         [0025]     The presence of the said lateral lid is not however necessary for implementing the present invention.  
         [0026]     The new and characteristic part of the box according to the invention regards the structure of its end lids formed by the closure panel  10  and the lip  13  connected to and projecting from it.  
         [0027]     As can be seen in particular from the enlarged scale reproduction of  FIG. 4 , a continuous arc-shaped elongate cut  16  is provided in the closure panel  10  to intersect the folding line  14  and extend beyond the line  14  into a portion of the lip  13 : the cut  16  is continued beyond its ends by a succession of separate short cuts  17  terminating with a knurling  18  which reaches the side edges of the panel  10  ( FIG. 4 ).  
         [0028]     After the box has been made up and closed ( FIG. 5 ), if an attempt is made to lift the end lid with a finger, an inevitable traction is exerted upwards on the panel  10  at the cut  16 , so causing the panel to break along the short cuts  17  and the knurlings  18 : the closure panel then assumes the attitude shown in  FIG. 6 , immediately highlighting the fact that the box has been tampered with.  
         [0029]     Even if, with the closure panel unbroken and with the end lid (of which it forms part) closed ( FIG. 5 ), a rigid blade is inserted between the panel  10  and the tabs  11  to attempt to fraudulently open the lid, the closure panel  10  will again be broken along the short cuts  17  and knurlings  18  given the small size and the consequent weakness of those points of the panel  10  where the panel is complete (i.e. without short cuts and knurlings) on its surface (along the arc-shaped line where the cut  16 , the short cuts  17  and the knurlings  18  are provided), while the lip  13  will sufficiently securely retain (even if there were no tab teeth  20  inserted and hooked into the lip apertures left free by the appendices  19 ) that portion of the panel  10  to which said lip  13  is connected along the folding lines  14 .  
         [0030]     Again considering  FIG. 1 , the box is made up by firstly rotating the panel  4  (and with it the flap  5 ) about the folding line  8  to superpose them on the panel  3 , then a thin strip of glue  25  is applied to the flap  5  in proximity to the folding line  9  ( FIG. 2 ), after which the panel  1  is rotated about its folding line  6  to superpose it on the flap  5 , to which it is then fixed by the strip of glue  25  ( FIG. 3 ).  
         [0031]     The box manufacturer has thus terminated box production, piles of flat mutually superposed boxes ( FIG. 3 ) then being despatched to the user firm which, by means of automatic machines of known type operating at high speed, shapes each box by firstly pressing the two opposing folding lines  6  and  9  towards each other (so that the box cross-section becomes rectangular), then automatically closes the bottom cover of the box, inserts into it the products to be contained, and finally closes the top cover.  
         [0032]     The box hence assumes the shape shown in perspective view in  FIG. 5 , in which the lip  13  (forming part of the box end lid visible in  FIGS. 5 and 6 ) is inserted below the panel  3  and securely retained thereat by the tabs  11  (as already fully described in the aforesaid prior patents).  
         [0033]     If an attempt is made (possibly using a rigid blade inserted between the closure panel  10  and the underlying tabs  11 ) to fraudulently open or tamper with the box end lid, of which the panel  10  forms part, the panel will certainly be broken.