SMOKING ARTICLE WITH IMPROVED AIRFLOW

• US 20150013697A1
• Filed: 02/12/2013
• Published: 01/15/2015
• Est. Priority Date: 02/13/2012
• Status: Active Grant

• Current Assignee: Philip Morris Products SA (Philip Morris Limited)
• Original Assignee: Philip Morris Products SA (Philip Morris Limited)
• Inventors: Mironov, Oleg
• Granted Patent: US 10,149,495 B2
• Time in Patent Office: Days
• US Class Current: 131/328
• CPC Class Codes: A24B 15/165 comprising as heat source a carbon fuel or an oxidized or thermally degraded carbonaceous fuel, e.g. carbohydrates, cellulosic material
• CPC Class Codes: A24D 1/22 Cigarettes with integrated combustible heat sources, e.g. with carbonaceous heat sources
• CPC Class Codes: A24F 42/60 Constructional details

Abstract

A smoking article having a mouth end and a distal end is provided, including a heat source; an aerosol-forming substrate downstream of the heat source; at least one air inlet downstream of the aerosol-forming substrate; and an airflow pathway extending between the at least one air inlet and the mouth end of the smoking article. The airflow pathway includes a first portion extending longitudinally upstream from the at least one air inlet towards the aerosol-forming substrate, and a second portion extending longitudinally downstream from the first portion to the mouth end of the smoking article.

Claims

1. A smoking article having a mouth end and a distal end, the smoking article comprising:

a heat source;

an aerosol-forming substrate downstream of the heat source;

at least one air inlet downstream of the aerosol-forming substrate; and

an airflow pathway extending between the at least one air inlet and the mouth end of the smoking article, wherein the airflow pathway comprises a first portion extending longitudinally upstream from the at least one air inlet towards the aerosol-forming substrate, and a second portion extending longitudinally downstream from the first portion towards the mouth end of the smoking article.

2. The smoking article according to claim 1, wherein the first portion of the airflow pathway extends upstream from the at least one air inlet to the aerosol-forming substrate, and the second portion of the airflow pathway extends downstream from the aerosol-forming substrate towards the mouth end of the smoking article.

3. The smoking article according to claim 1, wherein the first portion of the airflow pathway extends upstream from the at least one air inlet to the aerosol-forming substrate, and the second portion of the airflow pathway extends downstream from within the aerosol-forming substrate towards the mouth end of the smoking article.

4. The smoking article according to claim 1, wherein the first portion of the airflow pathway and the second portion of the airflow pathway are concentric.

5. The smoking article according to claim 1, wherein the first portion of the airflow pathway surrounds the second portion of the airflow pathway.

6. The smoking article according to claim 1, wherein the first portion of the airflow pathway and the second portion of the airflow pathway are of substantially constant transverse cross-section.

7. The smoking article according to claim 6, wherein the transverse cross-section of the first portion of the airflow pathway increases as the first portion of the airflow pathway extends upstream and the transverse cross-section of the second portion of the airflow pathway increases as the second portion of the airflow pathway extends downstream.

8. The smoking article according to claim 1, comprising:

an airflow directing element downstream of the aerosol-forming substrate, the airflow directing element defining the first portion of the airflow pathway and the second portion of the airflow pathway.

9. The smoking article according to claim 8, wherein the airflow directing element comprises an open-ended, substantially air impermeable hollow body.

10. The smoking article according to claim 9, wherein the hollow body is a right circular cylinder.

11. The smoking article according to claim 9, wherein the hollow body is a truncated right circular cone.

12. The smoking article according to claim 1, wherein the heat source is a combustible heat source.

13. The smoking article according to claim 12, wherein the combustible heat source is isolated from the airflow pathway such that air drawn along the airflow pathway does not directly contact the combustible heat source.

14. The smoking article according to claim 1, further comprising:

a heat-conducting element around and in contact with a rear portion of the heat source and a front portion of the aerosol-forming substrate.

15. A method of reducing or eliminating increases in temperature of an aerosol-forming substrate of a smoking article during puffing, the method comprising providing a smoking article, comprising:

a heat source;

an aerosol-forming substrate downstream of the heat source;

at least one air inlet downstream of the aerosol-forming substrate; and

an airflow pathway extending between the at least one air inlet and the mouth end of the smoking article, wherein the airflow pathway comprises a first portion extending longitudinally upstream from the at least one air inlet towards the aerosol-forming substrate, and a second portion extending longitudinally downstream from the first portion towards the mouth end of the smoking article,

such that, in use, air drawn into the smoking article through the at least one air inlet passes upstream through the first portion of the airflow pathway towards the aerosol-forming substrate and then downstream towards the mouth end of the smoking article through the second portion of the airflow pathway.