Filter for secondary smoke and smoking articles incorporating the same

A filter sleeve for filtering exhale smoke comprising a sleeve with

• a downstream portion adapted for communicating with a smoking article to receive inhale smoke from said smoking article;
• an upstream portion adapted for inhalation of said inhale smoke and for receiving of exhale smoke;
• at least one inhalation flow path from said downstream portion to said upstream portion, said inhalation flow path is provided for channeling of said inhale smoke for inhalation through said upstream portion;
• at least one exhalation flow path extending from said upstream portion to at least one exit into the ambient environment whereby exhale smoke received into said upstream portion is channeled through said exhalation flow path for filtration and discharge of filtered air into the ambient environment, wherein at least a significant portion of one flow path runs coaxially and within the other flow path, and wherein the exhalation flow path exits through a wall of the sleeve;
• filter means provided along at least one exhalation flow path, said filter means is provided for said filtration of received exhale smoke to produce filtered air, said filter means is of such efficiency as to render said filtered air substantially smoke-free;
• wherein the discharge of said filtered air into the ambient environment is significantly unimpeded by said smoking article when said smoking article is in flow communication with said downstream portion of the sleeve;
• and
• means for substantially checking the reverse flow of ambient air through said exhalation path, said means allow a considerably high rate of exhale flow to pass through said exhalation flow path.