Apparatus for perforating the wrappers of rod-shaped smokers' products and the like

Abstract

Tubular envelopes of successive rod-shaped products, such as cigarettes and/or filter rod sections, are caused to turn about their longitudinal axes and to simultaneously move sideways during advancement through a perforating station. At least one laser or another source of high-energy radiation directs at least one beam of radiation against a radiation-reflecting body which is caused to turn about its axis and has one or more curved, such as helical, surfaces serving to cause migration of and to simultaneously reflect the beam or beams upon one or more selected portions of the envelope of the rod-shaped product then moving through the perforating station. The thus refected beam(s) perforates or perforate the envelope being advanced through the station.

What is claimed is:  
     
         1 . Apparatus for providing successive tubular envelopes of rod-shaped products with regions of desired permeability while the envelopes advance through a perforating station, comprising: 
 a source arranged to emit at least one beam of high-energy radiation; and    a radiation-reflecting body rotatable about a predetermined axis and having at least one surface at least a section of which is curved and is arranged to reflect and to cause simultaneous migration of the at least one beam while said body rotates about said axis to thus direct the at least one beam against the envelope advancing through the perforating station with attendant formation of perforations therein.    
     
     
         2 . The apparatus of  claim 1 , wherein said section of said at least one surface is strip-shaped.  
     
     
         3 . The apparatus of  claim 1 , wherein said section of said at least one surface is a helix.  
     
     
         4 . The apparatus of  claim 3 , wherein said helix has an axis which is at least substantially parallel to said predetermined axis.  
     
     
         5 . The apparatus of  claim 3 , wherein said helix has an axis which at least substantially coincides with said predetermined axis.  
     
     
         6 . The apparatus of  claim 3 , wherein said source is arranged to direct said at least one beam upon said at least one surface at a predetermined angle of incidence, said helix having an axis which is at least substantially parallel to said at least one beam.  
     
     
         7 . The apparatus of  claim 1 , wherein said radiation reflecting body includes a cylinder having an axis coinciding with said predetermined axis and a peripheral surface including said at least one surface.  
     
     
         8 . The apparatus of  claim 1 , wherein said body has an external surface and said at least one surface is inclined relative to said external surface.  
     
     
         9 . The apparatus of  claim 1 , wherein said at least one surface includes a plurality of discrete curved sections.  
     
     
         10 . The apparatus of  claim 9 , wherein said body includes partitions intermediate said sections.  
     
     
         11 . The apparatus of  claim 10 , wherein each of said partitions includes one of (a) a step and (b) an uneven part of said body.  
     
     
         12 . The apparatus of  claim 10 , wherein each of said sections includes first and second end portions respectively disposed in discrete first and second planes at least substantially parallel to each other.  
     
     
         13 . The apparatus of  claim 12 , wherein said planes are at least substantially normal to said predetermined axis.  
     
     
         14 . The apparatus of  claim 12 , wherein said first and second planes of the first and second end portions of each of said sections are spaced apart from each other.  
     
     
         15 . The apparatus of  claim 12 , wherein said body has a peripheral surface and said sections are at least substantially uniformly distributed at said peripheral surface.  
     
     
         16 . The apparatus of  claim 9 , wherein said sections are at least substantially identical with each other regarding at least one of their (a) shapes, (b) directions and (c) leads.  
     
     
         17 . The apparatus of  claim 1 , wherein said section of said at least one surface is a helix having with respect to said axis a lead of at least close to 45°.  
     
     
         18 . The apparatus of  claim 1 , wherein said source includes at least one laser.  
     
     
         19 . The apparatus of  claim 18 , wherein said laser is arranged to emit at least one pulsed beam of corpuscular radiation.  
     
     
         20 . The apparatus of  claim 1 , wherein said source and said radiation-reflecting body are installed in a machine for making rod-shaped smokers' products.