Filter construction and method of forming same

Claim 1

A disposable filter affixed to the downstream end of an elongated tobacco rod, said filter comprising a cylindrical end member positioned adjacent the downstream end of the rod, said end member being provided with a passageway through which smoke from the tobacco rod is caused to flow longitudinally upon leaving the rod downstream end; a substantially rigid smoke barrier piece disposed in predetermined spaced, aligned, downstream relation with respect to the downstream end of said end member; a thin wall first sleeve unit of a flexible sheet material encompassing and sealingly contacting the outer periphery of said end member and said barrier piece and retaining same in said predetermined spaced relation, said first sleeve unit being provided with a set of small perforations arranged in sleeve unit-encircling relation and in registration with the space between the end member and said barrier piece and through which the smoke is caused to flow outwardly as high velocity smoke jets; and a smoke impervious second sleeve unit of a flexible sheet material encompassing said first unit whereby predetermined segments of the first unit exterior surface and the second unit interior surface are in closely spaced relation and form a shallow second passageway communicating with said set of perforations and circumventing said barrier piece, the high velocity smoke jets upon being emitted outwardly from said set of perforations impinging against the closely adjacent portions of the interior surface segment of said secoNd unit uniformly spaced radially outwardly of said perforations causing deposition thereon of solid and liquid particles entrained in the high velocity smoke jets, said shallow second passageway having a smoke discharge end disposed downstream of said barrier piece.