Container for tobacco articles and relative production method

Abstract

A container ( 1; 48; 52; 54 ) for tobacco articles, the container ( 1; 48; 52; 54 ) being formed from folded sheet material ( 9 ), and having at least one wall ( 7 ) defined by an inner portion ( 22, 23 ) and an outer portion ( 21, 24 ) of sheet material superimposed at least partly on each other; and the part of the inner portion ( 22, 23 ) covered by a corresponding part of the outer portion ( 21,10 24 ) is drawn to accommodate the thickness of the corresponding part of the outer portion ( 21, 24 ), so that the relative wall ( 7 ) has a substantially continuous outer surface with no steps or exposed free edges ( 31 ).

1 ) A container for tobacco articles, formed by folding a blank ( 9 ) comprising a central body ( 12 ) having a longitudinal axis ( 11 ) and divided into a number of panels ( 14 - 20 ) by preformed fold lines ( 13 ) crosswise to said longitudinal axis ( 11 ); the container ( 1 ;  48 ;  52 ;  54 ) comprising at least one double-layer wall ( 7 ) defined by an inner portion ( 22 ,  23 ) and an outer portion ( 21 ,  24 ) of sheet material ( 9 ) superimposed on each other; at least part ( 27 ) of said inner portion ( 22 ,  23 ) being covered by a corresponding part of said outer portion ( 21 ,  24 ); said part ( 27 ) of said inner portion ( 22 ,  23 ) being a depressed part ( 27 ) depressed by an amount at least equal to the thickness of said sheet material ( 9 ); at least some ( 14 ,  16 ,  17 ,  19 ) of the panels ( 14 - 20 ) of the blank ( 9 ) having opposite lateral flaps ( 21 - 24 ), each of which is folded squarely with respect to the relative panel ( 14 ;  16 ;  17 ;  19 ) and is superimposed at least partly on a corresponding flap ( 21 - 24 ) of another said panel ( 14 ;  16 ;  17 ;  19 ) to form a relative said double-layer wall ( 7 ); characterized in that said depressed part ( 27 ) is bounded by a respective free outer first edge ( 29 ) and by an inner second edge ( 30 ) connected to the rest of said sheet material ( 9 ), and said outer portion ( 21 ,  24 ) has a free outer third edge ( 31 ); said third edge ( 31 ) facing and being coplanar with said second edge ( 30 ).  
   
   
       2 ) A container as claimed in  claim 1 , wherein said second and third edge ( 30 ,  31 ) are complementary in shape.  
   
   
       3 ) A container as claimed in  claim 1 , wherein said second and third edge ( 30 ,  31 ) are straight.  
   
   
       4 ) A container as claimed in  claim 1 , wherein said second and third edge ( 30 ,  31 ) are curvilinear.  
   
   
       5 ) A container as claimed in  claim 1 , wherein said second and third edge ( 30 ,  31 ) are mixtilinear.  
   
   
       6 ) A method of producing a container for tobacco articles, the method comprising the step of folding a blank ( 9 ) to define, on the container ( 1 ;  48 ;  52 ;  54 ), at least one double-layer wall ( 7 ) comprising an inner portion ( 22 ,  23 ) and an outer portion ( 21 ,  24 ) of sheet material ( 9 ) superimposed on each other; at least part ( 27 ) of said inner portion ( 22 ,  23 ) being covered by a corresponding part of said outer portion ( 21 ,  24 ); the method comprising the further step of depressing said part ( 27 ) of said inner portion ( 22 ,  23 ) by an amount at least equal to the thickness of said sheet material ( 9 ); the blank ( 9 ) comprising a central body ( 12 ) having a longitudinal axis ( 11 ) and divided into a number of panels ( 14 - 20 ) by preformed fold lines ( 13 ) crosswise to said longitudinal axis ( 11 ); at least some ( 14 ,  16 ,  17 ,  19 ) of the panels ( 14 - 20 ) of the blank ( 9 ) having opposite lateral flaps ( 21 - 24 ), each of which is folded squarely with respect to the relative panel ( 14 ;  16 ;  17 ;  19 ) and is superimposed at least partly on a corresponding flap ( 21 - 24 ) of another said panel ( 14 ;  16 ;  17 ;  19 ) to form a relative said double-layer wall ( 7 ); the method being characterized in that said depressed part ( 27 ) is bounded by a respective free outer first edge ( 29 ) and by an inner second edge ( 30 ) connected to the rest of said sheet material ( 9 ), and said outer portion ( 21 ,  24 ) has a free outer third edge ( 31 ); said third edge ( 31 ) facing and being coplanar with said second edge ( 30 ).  
   
   
       7 ) A method as claimed in  claim 6 , wherein said part ( 27 ) of said inner portion ( 22 ,  23 ) is depressed by drawing.  
   
   
       8 ) A method as claimed in  claim 7 , wherein said drawing is performed using a die ( 36 ) and a counter-die ( 37 ).  
   
   
       9 ) A method as claimed in  claim 7 , wherein said drawing is performed by rolling.  
   
   
       10 ) A method as claimed in  claim 9 , wherein said rolling is performed in a direction parallel to said longitudinal axis ( 11 ).  
   
   
       11 ) A method as claimed in  claim 9 , wherein said rolling is performed in a direction crosswise to said longitudinal axis ( 11 ).  
   
   
       12 ) A method as claimed in  claim 11 , wherein said blank ( 9 ) forms part of a strip ( 40 ) defined by a succession of blanks ( 9 ) joined to one another and positioned with their longitudinal axes ( 11 ) crosswise to a travelling direction ( 41 ) of said strip ( 40 ).