Aerosol generating device with heater assembly

Abstract

An aerosol generating device is provided, including a housing configured to receive an aerosol-forming substrate having an internal cavity; a heating element configured to be received within the internal cavity of the substrate, and a positioning mechanism coupled to the heating element and to the housing being configured to move the heating element between a plurality of heating positions within the cavity. There is also provided an aerosol generating device including a housing configured to receive an aerosol-forming substrate, a heating element configured to heat a portion of the substrate, and a positioning mechanism configured to move the heating element from a first position next to a first portion of the substrate, to a second position remote from the substrate, and then to a third position next to a second portion of the substrate.

Claims

1. An aerosol generating device, comprising: a housing configured to receive an aerosol-forming substrate having an internal cavity; a heating element configured to be received within the internal cavity of the aerosol-forming substrate; and a positioning mechanism coupled to the heating element, the positioning mechanism being configured to move the heating element between a plurality of positions within the internal cavity.

2. The device according to claim 1, wherein the positioning mechanism further comprises an engagement mechanism configured to move the heating element towards and away from an interior surface of the internal cavity.

3. The device according to claim 2, wherein the engagement mechanism is configured to move the heating element into and out of contact with the interior surface of the internal cavity.

4. The device according to claim 1, wherein the aerosol-forming substrate is tubular such that the internal cavity is a bore having a longitudinal axis, wherein the device is configured to receive the tubular aerosol-forming substrate, and wherein the positioning mechanism is configured to move the heating element in a longitudinal direction.

5. The device according to claim 1, wherein the heating element is ring shaped or circular.

6. The device according to claim 5, wherein the heating element is resilient, wherein the positioning mechanism further comprises an engagement mechanism configured to move the heating element towards and away from an interior surface of the internal cavity, and wherein the engagement mechanism is attached to at least one end of the heating element, and is configured to move that end of the heating element in a circumferential direction to radially expand or contract the heating element.

7. The device according to claim 1, further comprising a microcontroller configured to control a supply of electrical power to the heating element and to activate the positioning mechanism following the supply of a predetermined amount or duration of electrical power to the heating element.

8. The device according to claim 1, wherein the positioning mechanism is configured to conduct electricity to the heating element.

9. The device according to claim 1, comprising a plurality of heating elements, wherein the positioning mechanism is configured to move each heating element of the plurality.

10. An aerosol generating device, comprising: a housing configured to receive an aerosol-forming substrate; a heating element configured to heat a portion of the aerosol-forming substrate; and a positioning mechanism configured to move the heating element from a first position next to a first portion of the aerosol-forming substrate, to a second position spaced apart from the aerosol-forming substrate, and then to a third position next to a second portion of the aerosol-forming substrate.

11. The device according to claim 10, wherein the aerosol-forming substrate is tubular or cylindrical and defines a longitudinal axis, wherein the housing is configured to receive the tubular or cylindrical aerosol-forming substrate, and wherein the third position is longitudinally removed from the first position.

12. The device according to claim 10, wherein the heating element is positioned externally of the aerosol-forming substrate in the first, second, or third positions.

13. The device according to claim 10, wherein the aerosol-forming substrate comprises a tubular portion, wherein the device is configured to receive the aerosol-forming substrate comprising the tubular portion, and wherein the heating element is configured to be positioned internally of the tubular portion in the first and third positions.

14. The device according to claim 10, wherein the heating element is ring shaped or circular.

15. The device according to claim 10, comprising a plurality of heating elements, wherein the positioning mechanism is configured to move each heating element of the plurality.

16. A method of heating an aerosol-forming substrate, comprising: moving a heating element into contact with or close to a first portion of a surface of the aerosol-forming substrate; activating the heating element to heat the first portion of the surface of the aerosol-forming substrate; moving the heating element away from the surface of the aerosol-forming substrate; moving the heating element into contact with or close to a second portion of the surface of the aerosol-forming substrate; and activating the heating element to heat the second portion of the surface of the aerosol-forming substrate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) An embodiment of the invention will further be described, by way of example only, with reference to the accompanying drawings, in which:

(2) FIG. 1 is a schematic view of the basic elements of an aerosol-generating device in accordance with the invention;

(3) FIG. 2 is a schematic representation of an aerosol-generating device according to one embodiment of the invention;

(4) FIG. 3 is schematic cross section of the device of FIG. 2;

(5) FIG. 4 is a schematic representation of an aerosol-generating device according to another embodiment of the invention;

(6) FIG. 5 is a schematic cross-section of the device of FIG. 4;

(7) FIG. 6 is a perspective view of a heater assembly in accordance with the embodiment of FIG. 2; and

(8) FIG. 7 is a flow diagram illustrating the steps taken during the operation of the device of FIG. 2.

DETAILED DESCRIPTION

(9) FIG. 1 is a schematic illustration of an electrically powered smoking device. The device comprises a housing 100 containing a battery 110, control electronics 120 and a heater 140, together with a positioning mechanism for moving the heater. The heater 140 is positioned within a socket 130 configured to receive a consumable element 150 containing an aerosol-forming substrate. The consumable element also comprises a filter element 160 through which a user inhales aerosol formed in the device. The aerosol-forming substrate is heated by the heater and releases vaporized flavor compounds. The vapors nucleate to form an aerosol, which is drawn through the filter 160 by a user inhalation.

(10) The heater is configured and controlled to provide short bursts of heat on a per-puff basis. The heater heats a new portion of the aerosol-forming substrate for each puff, to ensure that the desired amount and desired characteristics of aerosol are achieved.

(11) FIGS. 2 and 3 show the heater arrangement of FIG. 1 is more detail. The heater 140 is positioned and configured to be received in a cavity within the aerosol-forming substrate. The cavity includes an air inlet 170. The aerosol-forming substrate 180 is formed in a tubular shape and defines an internal bore having a longitudinal axis. A flow sensor is also provided to detect the air flow through the device. The heater 140 comprises a substantially ring shaped or circular heating element 200 mounted on a support 210. The heating element 200 in this example has a helical shape. A positioning mechanism is configured to move the heating element longitudinally in the direction of arrow A. This may be achieved by moving the heating element 200 alone or by moving the support column 210. A more detailed description of one particular arrangement is provided below with reference to FIG. 6.

(12) The positioning mechanism includes an engagement mechanism for moving the heating element towards and away from the aerosol-forming substrate during a positioning process. FIG. 3 is a cross-sectional view through the heating element of FIG. 2 and illustrates the engagement mechanism. One end of the heating element 200 is connected to the support 210 by a first radial arm 220 and the other end of the heating element by a second radial arm 230. Rotation of the first and second radial arms 220 and 230 relative to one another changes the radius of curvature of the heating element 200, so that the heating element can be radially expanded and contracted. In a first, expanded position, the heating element is in contact with the aerosol-forming substrate along substantially its entire length. In a second, retracted position, the heating element 200 is spaced from the aerosol-forming substrate, allowing it to be more easily moved in the longitudinal direction. The relative rotation of the first and second radial arms may be achieved by rotating one arm and keeping the other fixed relative to the housing, or by rotating both arms, simultaneously or sequentially.

(13) Electrical power is supplied to the heating element 200 through the support 210. The support itself may be formed fully or partially from conductive material, or a separate conductive path may be provided on or within the support 210.

(14) FIG. 4 is a schematic illustration of an alternative heater arrangement and positioning mechanism in accordance with the invention. The heater of FIG. 4 comprises an elongate heating element 400 mounted on support 410 and radial arms 420. The heating element 400 is configured to heat a section of the aerosol-forming substrate along substantially the entire length of the bore. The heating element is rotated to heat different sections of the aerosol-forming substrate by the positioning mechanism, which comprises support 410 and a stepper motor (not shown) for rotating the support.

(15) The heating element 400 in FIG. 4 is shown in contact with the aerosol-forming substrate 180. The heating element may be retracted by an engagement mechanism configured to move the arms 420 away from the aerosol-forming substrate using an electromagnetic actuator.

(16) Electrical power is supplied to the heating element 400 through the support 410. The support itself may be formed fully or partially from conductive material, or a separate conductive path may be provided on or within the support 410.

(17) FIG. 5 is an end view of the heater arrangement of FIG. 4.

(18) FIG. 6 shows an engagement mechanism for expanding and contracting a heating element of the type shown in FIGS. 2 and 3. The engagement mechanism includes a push button 600. Depression of the button 600 applies a rotation to support rods 610. The engagement mechanism is configured such that it applies rotation to one rod in an opposite sense to the other rod. The rotational movement is transmitted to the torsion bars 620, which are fixed to either end of a helical heating element 630. The torsion bars and support rods are stiffer than the heating element. The rotation of the torsion bars increases the angular distance traveled by the heating element and so reduces the diameter of the helical heating element. With the button 600 depressed the heating element 630 is therefore spaced apart from the aerosol-forming substrate and can be moved in a longitudinal direction to a new position without frictional interference with the aerosol-forming substrate.

(19) When the button is released, the resilient heating element 630 springs back to its original shape and so once again contacts the aerosol-forming substrate. Additional biasing means may be provided within the button mechanism if required. Electrical contacts 640 are spring biased into contact with the support rods 610 so that electrical contact is maintained while allowing the support rods to rotate.

(20) The heating element is moved longitudinally using a manually operated longitudinal positioning mechanism. The whole assembly shown in FIG. 6 may be moved within the housing of the device. Flexible wiring may be used to provide the electrical contact between contacts 640 and electrical contacts fixed to the housing (not shown) so that longitudinal movement of the assembly can be accommodated while still allowing for a supply of electrical power. The longitudinal movement of the assembly may be a simple sliding movement of the support element 650 along an internal bore of the housing. A resilient arm or protrusion may be provided on the support element for engagement with features on the internal surface of the bore to provide a clicking noise as they pass one another. The features on the internal surface of the bore may be spaced apart such that a single clicking noise informs the user that the heating element is adjacent a new, unheated section of the aerosol-forming substrate.

(21) More complex mechanisms for longitudinal movement of the heating element are of course possible including automatic mechanisms that move the heating element longitudinally when button 600 is depressed or following each activation of the heating element or sensed user inhalation. Such automatic mechanisms may be powered by a permanent magnet and solenoid or by a stepper motor for example.

(22) It is also possible to include a position detection mechanism together with a manually operated positioning mechanism in order to prevent heating of the same portion of the aerosol-forming substrate twice. For example, an optical sensor may be incorporated into the assembly or housing to determine the position of the heating element. The microcontroller may then disable the supply of power to the heating element or issue a visible or audible alarm if it is determined to be in a position in which it has already been activated for the current aerosol-forming substrate.

(23) FIG. 7 is a flow diagram illustrating an example of the operation of a heater in accordance with FIGS. 2, 3 and 6. When a new aerosol-forming substrate is to be inserted into the socket, the heating element is in a contracted configuration. In the system shown in FIG. 6, this means that the button 600 is pressed. In step 700, once a new aerosol-forming substrate has been inserted, the heating element is expanded by the engagement mechanism to contact the interior surface of the aerosol-forming substrate. The heating element is positioned as close to the filter end of the aerosol-forming substrate as possible. This minimizes the time to first puff for the user. In step 705, a flow of air through the device is detected by the flow sensor, indicating that a user is taking a puff. Following detection of air flow, the microcontroller supplied power to the heating element in step 710. After a fixed duration or fixed amount of power, the microcontroller switches off the power to the heating element, in step 715.

(24) In step 720, a puff count for the aerosol-forming substrate is incremented. The puff count is used to ensure that only a fixed number of heating cycles are used on each aerosol-forming substrate so that no section of the aerosol-forming substrate is heated twice. The puff count increase can be carried out before, simultaneous with or after the supply of power to the heating element.

(25) In step 725, the microcontroller checks the puff count to determine if the aerosol-forming substrate needs to be replaced. If not, the heating element is moved to a new portion of the aerosol-forming substrate by the positioning mechanism. First, in step 730, the heating element is contracted by pressing the button 600 (or by automatic means). The heating element is then moved longitudinally to new position in step 735, as described with reference to FIG. 7. The new position may be directly adjacent the previous position or may be distant from it. In this example, the heating element is simply moved to an adjacent position, one step further from the filter end of the aerosol-forming substrate. Once in the desired longitudinal position, the button 600 is released and the heating element expands to contact the new portion of the aerosol-forming substrate in step 740. The heating element is then ready to supply the next puff and the process then returns to step 705.

(26) If in step 725 the microcontroller determines that all available areas of the aerosol-forming substrate have been used, then the aerosol-forming substrate must be replaced. A visual or audible indication may be provided to the user. In order to replace the aerosol-forming substrate, the button 600 is pressed to contract the heating element in step 745. The aerosol-forming substrate can then be easily slid out of the device. While the heating element is contracted, it is moved longitudinally to the start position closest to the filter in step 750. To insert a new aerosol-forming substrate, the button remains pressed, or is pressed again if it has been released, to contract the heating element. In step 755, if an automated mechanism is used, the heating element can be held in a contracted state until a new aerosol-forming substrate is detected. Once a new aerosol-forming substrate is detected the process begins again at step 700.