Pack with a tear strip and device for production thereof

Abstract

A cuboidal cigarette pack of the hinge-lid-box type ( 10 ) is enclosed by an outer wrapper made of film. The latter has a tear-open thread ( 24 ) which extends obliquely or diagonally in the region of a front wall ( 14 ) and rear wall ( 15 ) and merges into side walls ( 16, 17 ) via arcuate regions. This allows optimum opening and removal of the outer wrapper with the aid of the tear-open thread ( 24 ).

1 . In a cuboidal pack, in particular cigarette pack (rigid pack), with an outer wrapper which is made of film or other tearable packaging material, and which is provided with a tear-open strip, the improvement wherein the tear-open strip ( 24 ), in a region of a large-surface-area front wall ( 14 ) and/or rear wall, ( 15 ) of the pack, extends obliquely or approximately diagonally from one (bottom) pack corner ( 28 ) to a diagonally opposite (top) pack corner ( 29 ).  
   
   
       2 . The pack as claimed in  claim 1 , characterized in that the tear-open thread ( 24 ), in the region of narrow side walls ( 16 ,  17 ) extends transversely to the latter, preferably directly adjacent to an end wall ( 18 ) or base wall ( 19 ).  
   
   
       3 . The pack as claimed in  claim 1 , characterized in that the tear-open thread ( 24 ), in the region from one thread section ( 26 ,  27 ) to another thread section ( 31 ,  32 ), is of arcuate configuration, with a rounded portion ( 30 ) being formed in the process.  
   
   
       4 . The pack as claimed in  claim 1 , characterized in that thread sections ( 26 ,  27 ), which extend obliquely or diagonally in the region of the front wall ( 14 ) and rear wall ( 15 ), extend at the same angle of inclination, which is directed in the same direction, and in that ends of the single-piece tear-open thread ( 24 ) overlap one another, in particular in the region of the transversely directed thread section ( 32 ), in the region of a side wall ( 17 ), adjacent to or beneath an end wall ( 18 ).  
   
   
       5 . A process for producing blanks ( 12 ,  13 ) from film, paper or other tearable packaging material in order to form outer wrappers of a cuboidal (cigarette) pack with a tear-open thread ( 24 ) which is fitted on the outer wrapper and is fed continuously to a continuously conveyed web ( 33 ) of the packaging material and is positioned on said web, characterized in that the tear-open thread ( 24 ) is moved, at least in sub-regions, transversely to the conveying direction of the web ( 33 ) such that the tear-open thread ( 24 ) butting against the web ( 33 ) is directed, in sub-regions, obliquely in relation to the conveying direction of the web.  
   
   
       6 . The process as claimed in  claim 5 , characterized in that the tear-open thread ( 24 ) is guided in a controlled manner in undulating fashion transversely to the movement direction of the web ( 33 ) and, temporarily, in this movement direction, such that the tear-open thread ( 24 ) butting against the web ( 33 ) has an undulating, in particular more or less meandering, configuration.  
   
   
       7 . The process as claimed in  claim 5 , characterized in that the tear-open thread ( 24 ), in the region of transitions between obliquely directed thread sections ( 26 ,  27 ) and thread sections ( 31 ,  32 ), which run in the conveying direction of the web ( 33 ), and vice versa, rounded portions ( 30 ) of the tear-open thread ( 24 ) are formed as transitions.  
   
   
       8 . A process for producing blanks ( 12 ,  13 ) from film, paper or other tearable packaging material in order to form outer wrappers of a cuboidal (cigarette) pack with a tear-open thread ( 24 ) which is fitted on the outer wrapper and is cut off, as an open-ended thread section, from a thread web ( 71 ,  72 ) by a transversely directed severing cut and positioned on a continuous web ( 33 ) of the packaging material, characterized in that a contoured tear-open thread ( 24 ) is cut off from the thread web ( 71 ,  72 ) by a correspondingly shaped thread cutter ( 69 ,  70 ) and positioned on the web ( 33 ), in the region of a blank ( 12 ,  13 ), such that obliquely or diagonally running thread sections ( 26 ,  27 ) are formed in the region of a front wall ( 14 ) and/or rear wall ( 15 ).  
   
   
       9 . The process as claimed in  claim 8 , characterized in that the contoured tear-open thread ( 24 ) is positioned on the web ( 33 ) or on the blank ( 12 ,  13 ), such that one end region of the tear-open thread ( 24 ) extends into a grip tab ( 25 ) of the blank ( 12 ,  13 ) and another end of the tear-open thread ( 24 ) terminates in the adjacent blank ( 12 ,  13 ) at a distance from the grip tab ( 25 ).  
   
   
       10 . An apparatus for producing blanks ( 12 ,  13 ) for outer wrappers made of film, paper or the like for cuboidal packs, in particular cigarette packs, with a tear-open thread ( 24 ) fitted on the outer wrapper, characterized in that, in a packaging machine for fitting the blanks ( 12 ,  13 ), a thread unit ( 39 ) is preferably arranged as a separate subassembly, by means of which a tear-open thread ( 24 ) drawn off from a thread reel ( 40 ) is positioned on a packaging-material web ( 33 ) fed to the thread unit ( 39 ), the thread unit ( 39 ) having a guide element for the tear-open thread ( 24 )—guide roller ( 35 )—which can be moved transversely to the conveying direction of the web ( 33 ) in order to form sections of the tear-open thread ( 24 ) which run at an angle to the conveying direction of the web ( 33 ).  
   
   
       11 . The apparatus as claimed in  claim 10 , characterized in that the guide element for the tear-open thread ( 24 ), in particular the guide roller ( 35 ), is fitted on a mount—guide carriage ( 53 )—which can be moved transversely to the movement direction of the web ( 33 ), it being possible for the guide carriage ( 53 ) to be moved back and forth in accordance with the configuration of the tear-open thread ( 24 ) which is to be produced on the web ( 33 ).  
   
   
       12 . The apparatus as claimed in  claim 10 , characterized in that the guide roller ( 35 ) can be pivoted about an axis transverse to the axis of rotation such that the guide roller ( 35 ) can be aligned with the running direction of the tear-open thread ( 24 ) during transfer to the web ( 33 ).  
   
   
       13 . The apparatus as claimed in  claim 12 , characterized in that the pivotable guide roller ( 35 ) is assigned a pivoting gear mechanism, in particular a connecting rod ( 58 ) which can be moved in a controlled manner and is connected, via a pivoting arm ( 60 ), to the guide roller ( 35 ) or a rotatable mount ( 57 ) of the same.  
   
   
       14 . The apparatus as claimed in  claim 10 , characterized by a speed-compensating element of the tear-open thread ( 24 ), which can be fed to the thread unit ( 39 ) at constant conveying speed and can be positioned on the web ( 33 ) at a non-uniform speed.  
   
   
       15 . The apparatus as claimed in  claim 14 , characterized in that the speed-compensating element is a precisely controlled dancer roller ( 44 ), which can be moved by a servomotor ( 49 ) and around which the tear-open thread can be guided, or an eccentric, rotatable compensating disk ( 37 ), the tear-open thread butting against its circumference.  
   
   
       16 . An apparatus for producing blanks ( 12 ,  13 ) for outer wrappers made of film, paper or the like for cuboidal packs, in particular cigarette packs, with a tear-open thread ( 24 ) fitted on the blank ( 12 ,  13 ), characterized in that, in a packaging machine for fitting the blanks ( 12 ,  13 ) on the packs, a thread unit ( 39 ) is preferably arranged as a separate subassembly which, by means of a contoured thread cutter ( 69 ,  70 ), cuts off correspondingly configured undulating, meandering or zigzag tear-open threads ( 24 ) from a thread web ( 71 ,  72 ) and positions them on a packaging-material web ( 33 ), which runs transversely to the thread web ( 71 ,  72 ) in the region of a blank ( 12 ,  13 ) which is to be produced.  
   
   
       17 . The apparatus as claimed in  claim 16 , characterized in that the contoured thread cutter ( 69 ,  70 ) is fitted on a correspondingly shaped carrying element, namely bar ( 85 ), which has suction bores ( 79 ) for retaining the cut-off tear-open thread ( 24 ), it being possible, by continued (upward) movement of the bar ( 85 ) for the cut-off tear-open thread ( 24 ) to be pressed onto an (under)side of the web ( 33 ).  
   
   
       18 . The apparatus as claimed in  claim 16 , characterized in that, for double-web operation, it is possible for two thread webs ( 71 ,  72 ) to be fed to a cutting block ( 73 ) and for two (contoured) tear-open threads ( 24 ) to be cut off within the same by means of two thread cutters ( 69 ,  70 ), which can be moved (upward) at the same time, and to be fed to a common, double-width web ( 33 ), it preferably being possible for a first thread web ( 71 ) to be introduced into the cutting block ( 73 ) directly in a horizontal plane, and for a second thread web ( 72 ) to be introduced into the common cutting block ( 73 ) from the underside, via deflecting rollers ( 88 ), such that the two thread webs ( 71 ,  72 ) are positioned in a common horizontal plane in order for in each case one tear-open thread ( 24 ) to be cut off.  
   
   
       19 . The apparatus as claimed in  claim 18 , characterized in that the two thread cutters ( 69 ,  70 ) or the carriers thereof—bars ( 85 )—can be moved up and down by a common actuating element, namely by a carrying arm ( 86 ) which can be moved up and down and grips the bars ( 85 ) with the thread cutters ( 69 ,  70 ) at both ends.  
   
   
       20 . The improvement according to  claim 1 , wherein the tear-open strip is a thread fitted on the outer wrapper of the pack.