Patent EA-001927-B1 (EA)
Title: Cigarette proided with an inertial hyrobaric device such as to retain the tar in tobacco smoke and/or device as above not essentially inserted into a cigarette
Inventor: LEONETTI LUPARINI ALESANDRO
IPC: A24D3/04
Filed: 1997-12-31
Abstract: 1. A retention device for insertion in the smoke path of cigarette between the point of combustion and the smoker, for removing tar from the smoke by promoting its deposition within the device, said device comprising: an inlet duct through which smoke from the site of combustion is drawn at an accelerated flow rate; a hypobaric chamber into which the smoke enters upon exiting the inlet duct; and an outlet duct through which the smoke leaves the hypobaric chamber at an accelerated flow rate, thereby causing a static pressure drop within the hypobaric chamber, and wherein the path through the hypobaric chamber between the inlet and outlet ducts is non-linear, such that in use the reduction of pressure and the non-linear flow of smoke causes tar within the smoke to deposit on the surface of the hypobaric chamber. 2. A retention device as claimed in claim 1 in which the flow area of the inlet duct is smaller than the flow area of the outlet duct. 3. A retention device as claimed in claim 1 or 2 which is used in combination with other tar removing devices. 4. A retention device as claimed in any of claims 1 to 3 in which the parts are cleanable to remove deposited tar, thereby permitting reuse of the device. 5. A retention device as claimed in any of the preceding claims which comprises at least two hypobaric chambers which are arranged in series so that the outlet duct from the first chamber directly communicates with an inlet duct of the second hypobaric chamber. 6. A retention device as claimed in any of the preceding claims wherein the chamber is generally cylindrical with two opposed end faces, the inlet duct projecting into the chamber from one end face and the outlet duct projecting into the chamber from the other end face out of alignment with the inlet duct. 7. A retention device as claimed in claim 6 in which the inlet and outlet ducts extend more than halfway into the hypobaric chamber. 8. A retention device as claimed in any of the preceding claims in which the inlet duct tapers toward its end from which the smoke exits, and the outlet duct tapers toward its end into which the smoke enters. 9. A retention device as claimed in any of the preceding claims wherein the inlet and outlet ducts are substantially circular in cross-section. 10. A retention device as claimed in claim 9 wherein the inlet duct has a diameter in the range of 0.5 to 0.8 mm, the outlet duct has a diameter in the range of 1 to 2 mm; and the hypobaric chamber has a volume in the range of 0.25 to 1.5 cm3. 11. A retention device as claimed in any of the preceding claims which is configured for removable attachment to a cigarette in the smoke exit area thereof. 12. A retention device as claimed in any of the claims 1 to 10 which is integrally formed within a cigarette. 13. A retention device as claimed in any of the preceding claims in which at least two inlet ducts are provided. 14. A retention device as claimed in any of the preceding claims in which at least two outlet ducts are provided. 15. A cigarette comprising a tobacco filled tube with a smoke exit end through which the smoke is drawn, in which a retention device according to any of the preceding claims is included in the cigarette at or adjacent the smoke exit end, so that the smoke drawn by the smoker passes through the retention device.