Cigarette sidestream smoke and free-burn rate control device

Abstract

A device for minimizing cigarette sidestream smoke and reducing free-burn rate of a burning cigarette is disclosed. The device comprises a non-combustible tubular element encasing an effective length of a tobacco charge of a cigarette located in the tubular element. The tubular element minimizes sidestream smoke emission from a burning tobacco charge and reduces free-burn rate of such burning tobacco charge to increase the number of puffs from the burning tobacco charge.

1 . A device for minimizing cigarette sidestream smoke and reducing free-burn rate of a burning cigarette in combination with a filter tip, 
 A) said device comprising: 
 i) a non-combustible porous tubular element encasing an effective length of a tobacco charge of a cigarette located in said tubular element, said tubular element having an open end adjacent a distal end of said cigarette to permit lighting of the cigarette distal end and to permit ingress of air; and  
 ii) said tubular element having a predetermined porosity along at least its length which encases said effective length of said tobacco charge for both minimizing sidestream smoke emission from a burning tobacco charge and reducing free-burn rate of such burning tobacco charge to increase number of puffs from such burning tobacco charge; and  
   B) said filter tip comprising an inlet end and an outlet end, said inlet end having an annular sleeve with a central bore to receive an end of said cigarette, said annular sleeve having an outer shoulder onto which said tubular element is friction fitted, said central bore being in communication with a first inner tube of a first filter material, said tube having a closed end opposite its end in communication with said sleeve central bore, an annular space being provided outside of said first tube, a filter plug provided downstream of said annular space and filling said outlet end of said filter tip, a plenum between said filter plug and said first tube for transferring filter smoke from said annular space to said filter plug.    
     
     
         2 . The device in combination with the filter tip of  claim 1  wherein said effective length of said tobacco has a diameter in the range of about 4 to about 6 mm.  
     
     
         3 . The device in combination with the filter tip of  claim 1  wherein a second tube of a second filter material is concentrically located in said annular space about said first tube.  
     
     
         4 . The device in combination with the filter tip of  claim 3  wherein said filter material of said first and second tubes is selected from a group of materials consisting of cellulosic material, glass ceramic or carbon fibre matting material, activated charcoal material, micro-fibre material and any of said materials incorporating a catalytic material.  
     
     
         5 . The device in combination with the filter tip of  claim 1  having an annulus between tube interior surface and cigarette periphery, said annulus defining a gap spacing of about 0.5 mm to about 3 mm and preferably about 1.5 to 2.5 mm.  
     
     
         6 . The device in combination with the filter tip of  claim 1  wherein a cigarette to be inserted in said tubular element is inherently unsmokeable and becomes smokeable when inserted in said tubular element.  
     
     
         7 . The device in combination with the filter tip of  claim 1  wherein a cigarette to be inserted in said tubular element has a filter element which is sufficiently porous to render the cigarette inherently unsmokeable and becomes smokeable when inserted in a filter tip portion of said tubular element.  
     
     
         8 . The device in combination with the filter tip of  claim 1  wherein said open end of said tubular element is open while said cigarette is smoked and said open end is adjacent a distal end of said cigarette.  
     
     
         9 . The device in combination with the filter tip of  claim 1  wherein said predetermined porosity for said tubular element: 
 a) retains around a burning ember of said cigarette oxygen deprived combustion gases within said tubular element to reduce rate of combustion and minimizes release of smoke particles through said porous tubular element; and  
 b) restricts inward flow of air to reduce free-burn rate of said cigarette.  
 
     
     
         10 . A device for minimizing cigarette sidestream smoke and reducing free-burn rate of a burning cigarette, said device comprising: 
 i) a non-combustible tubular element encasing an effective length of a tobacco charge of a cigarette located in said tubular element; and    ii) said tubular element comprising ceramic material and having a means for both minimizing sidestream smoke emission from a burning tobacco charge and reducing free-burn rate of such burning tobacco charge to increase number of puffs from said burning tobacco charge.    
     
     
         11 . A device for minimizing cigarette sidestream smoke and reducing free-burn rate of a burning cigarette, said device comprising: 
 i) a non-combustible tubular element encasing an effective length of a tobacco charge of a cigarette located in said tubular element; and    ii) said tubular element comprising ceramic material and having a porosity for both minimizing sidestream smoke emission from a burning tobacco charge and reducing free-burn rate of such burning tobacco charge to increase number of puffs from said burning tobacco charge.