Electrically-powered linear heating element

• US 5,093,894 A
• Filed: 12/01/1989
• Issued: 03/03/1992
• Est. Priority Date: 12/01/1989
• Status: Expired due to Term

• Current Assignee: Philip Morris USA Incorporated (Altria Group, Inc.)
• Original Assignee: Philip Morris USA Incorporated (Altria Group, Inc.)
• Inventors: Deevi, Seetharama C., Sprinkel, Francis M.
• Primary Examiner(s): Walberg, Teresa J.
• Application Number:
  US07/444,569
• Time in Patent Office: 823 Days
• Field of Search: 219/271-276, 219/543, 338/306-309, 338/292, 338/293, 392/390, 392/395, 392/403, 392/404
• US Class Current: 392/390
• CPC Class Codes: A24F 40/20 Devices using solid inhalable precursors
• CPC Class Codes: A24F 40/46 Shape or structure of electric heating means

Abstract

A heating element for use within a smoking device which is intended to be held in the lips of a consumer, and which without burning, heats a flavor-generating medium within the device to produce an aerosol, vapor, or flavor, which the consumer may inhale. More particularly, an electrically-powered heating element having a plurality of discrete resistive heating segments, only one of which is active at any given time. In a preferred embodiment, the heating element is contained within the device so that the individual heating segments of the element are adjacent to a flavor-generating medium. As each segment of the heating element is provided with power, the flavor-generating medium adjacent to that segment is heated, but is not burned. This heating causes the flavor-generating medium to produce a flavor, aerosol, or vapor, which the consumer of the device may inhale.

Claims

1. An electrically-powered linear heating element enclosed within a device adapted to be supported by the lips of an individual, comprising:

a linear base member;

an electrically-resistive linear heating member switchably connectable to an electrical power source, said heating member having a resistivity which, when said heating member is connected to said power source, causes the heating member to attain a temperature sufficient to heat, without burning, a flavor-generating medium which is in thermal contact with said heating member; and

a linear insulating member secured between the base member and the heating member, said insulating member having an electrical resistance sufficiently high to electrically isolate the heating member from the base member, said insulating member also having a thermal conductivity sufficiently low to thermally isolate the heating member from the base member.

2. The electrically-powered heating element of claim 1 wherein the electrically-resistive heating member comprises a plurality of electrically-discrete resistive segments, each of which is switchably and independently connectable to an electrical power source.

3. The electrically-powered heating element of claim 1 wherein the electrically-resistive heating member has a resistance of between 0.2 and 20.0 ohms.

4. The electrically-powered heating element of claim 3 wherein the electrically-resistive heating member has a resistance of between about 0.5 and 1.5 ohms.

5. The electrically-powered heating element of claim 4 wherein the electrically-resistive heating member has a resistance of between about 0.8 and 1.2 ohms.

6. The electrically-powered heating element of claim 1 wherein the heating element is of a size which could be contained within a smoking device having an outside diameter of between 6 and 18 millimeters.

13. The electrically-powered heating element of claims 1 or 7 wherein the base member comprises an element selected from the group consisting of metallic tape, metallic or nonmetallic oxide, carbides, nitrides, silicides, carbonnitrides, inter-metallic compounds, and cermet.

26. The electrically-powered heating element of claims 1, 7, 14, or 20 wherein the base member comprises a mat of non-woven fibers.

27. The electrically-powered heating element of claims 1, 7, 14, or 20 wherein the base member comprises a mat of woven fibers.

28. The electrically-powered heating element of claims 1, 7, 14, or 20 wherein the heating element is encased in a protective coating, said protective coating providing a physical and chemical barrier between the heating element and its surroundings, and being substantially chemically non-reactive with the other components of the heating element and with the environment in which the heating element is to be used.

29. The electrically-powered heating element of claims 1 or 7 wherein the base member comprises a metallic tape, and wherein the heating element is encased in a protective coating, said protective coating providing a physical and chemical barrier between the heating element and its surroundings, and also being substantially chemically non-reactive with the other components of the heating element and with the environment in which the heating element is to be used.

7. An electrically-powered linear heating element enclosed within a smoking device adapted to be supported by the lips of an individual, comprising:

a linear base member;

a pair of electrically-resistive linear heating members switchably connectable to an electrical power source, each of said heating members having a resistivity which, when each member is connected to said power source, causes each of the heating members to attain a temperature sufficient to heat a flavor-generating medium PG,22 which is in thermal contact with said heating members without burning; and

a pair of linear insulating members, each disposed along a respective side of the base member and secured to a respective one of the resistive heating members, said insulating members having an electrical resistance sufficiently high to electrically isolate the heating members from the base member, said insulating member also having a thermal conductivity sufficiently low to thermally isolate the heating member from the base member.

8. The electrically-powered heating element of claim 7 wherein each electrically-resistivity heating member comprises a plurality of electrically-discrete resistive segments, each of which is switchably connectable to an electrical power source.

9. The electrically-powered heating element of claim 7 wherein the electrically-resistive heating member has a resistance of between 0.2 and 20.0 ohms.

10. The electrically-powered heating element of claim 9 wherein the electrically-resistive heating member has a resistance of between about 0.5 and 1.5 ohms.

11. The electrically-powered heating element of claim 10 wherein the electrically-resistive heating member has a resistance of between about 0.8 and 1.2 ohms.

12. The electrically-powered heating element of claim 7 wherein the heating element is of a size which could be contained within a smoking device having an outside diameter of between 6 and 18 millimeters.

14. An electrically-powered linear heating element enclosed within a smoking device adapted to be supported by the lips of an individual, comprising:

an electrically-resistive linear heating member switchably connectable to an electrical power source, said heating member having a resistivity which, when said heating member is connected to said power source, causes the heating member to attain a temperature sufficient to heat a flavor-generating medium which is in thermal contact with said heating member; and

a linear base member secured to said heating member, said base member comprising an electrically-insulating material capable of maintaining its structural integrity and chemical inertness throughout the range of operating temperatures of the heating member.

15. The electrically-powered heating element of claim 14 wherein the electrically-resistive heating member comprises a plurality of electrically-discrete resistive segments, each of which is switchably and independently connectable to an electrical power source.

16. The electrically-powered heating element of claim 14 wherein the electrically-resistive heating member has a resistance of between 0.2 and 20.0 ohms.

17. The electrically-powered heating element of claim 16 wherein the electrically-resistive heating member has a resistance of between about 0.5 and 1.5 ohms.

18. The electrically-powered heating element of claim 17 wherein the electrically-resistive heating member has a resistance of between about 0.8 and 1.2 ohms.

19. The electrically-powered heating element of claim 14 wherein the heating element is of a size which could be contained within a smoking device having an outside diameter of between 6 and 18 millimeters.

20. An electrically-powered linear heating element enclosed within a smoking device adapted to be supported by the lips of an individual, comprising:

a pair of electrically-resistive linear heating members switchably connectable to an electrical power source, each of said heating members having a resistivity which, when each member is connected to said power source, causes each of the heating members to attain a temperature sufficient to heat a flavor-generating medium in thermal contact with said heating members; and

a linear base member, secured and interposed between each of said heating members, comprising an electrically-insulating material capable of maintaining its structural integrity and chemical inertness throughout the range operating temperatures of the heating members.

21. The electrically-powered heating element of claim 20 wherein each electrically-resistive heating member comprises a plurality of electrically-discrete resistive segments, each of which is switchably connectable to a power source.

22. The electrically-powered heating element of claim 20 wherein the electrically-resistive heating member has a resistance of between 0.2 and 20.0 ohms.

23. The electrically-powered heating element of claim 22 wherein the electrically-resistive heating member has a resistance of between about 0.5 and 1.5 ohms.

24. The electrically-powered heating element of claim 23 wherein the electrically-resistive heating member has a resistance of between about 0.8 and 1.2 ohms.

25. The electrically-powered heating element of claim 20 wherein the heating element is of a size which could be contained within a smoking device having an outside diameter of between 6 and 18 millimeters.