Patent ID: 8424539

Claim:
A smoking article comprising a tobacco rod extending in an axial direction, a filter and a tipping paper operatively connecting said filter with said tobacco rod, said filter comprising a single piece restrictor filter segment having a fluted section, a frusto-conical section having an open upstream end and a closed downstream end, orifices that establish both a desired resistance to draw and a mixing of mainstream smoke with ventilation air, and a downstream plug of filter material, wherein outer peripheries of the fluted section and the frusto-conical section are adjacent the tipping paper and wherein the fluted section includes at least two walls defining voids between the walls and each of the orifices is in fluid communication with one of the voids, the walls of the fluted section terminating in a plane perpendicular to the axial direction and in contact with the downstream plug of filter material, wherein ventilation holes are located along said filter downstream of said orifices and in fluid communication with one or more of said voids.