HEATING ELEMENT MODULE FOR AN AEROSOL-GENERATING DEVICE

Abstract

A heating element module for an aerosol-generating device is provided, including an elongate heating element having a heating portion; a heating element mount, wherein the heating element extends substantially perpendicularly from a first surface of the heating element mount; and first and second projections extending substantially perpendicularly from the first surface of the heating element mount and abutting first and second sides of the heating element. An aerosol-generating device incorporating the heating element module is also provided.

Claims

1.-10. (canceled)

11. A heating element module for an aerosol-generating device, comprising: an elongate heating element having a heating portion; a heating element mount, wherein the elongate heating element extends substantially perpendicularly from a first surface of the heating element mount; and first and second projections extending substantially perpendicularly from the first surface of the heating element mount and abutting first and second sides of the elongate heating element.

12. The heating element module according to claim 11, wherein a portion of the elongate heating element extending from the first surface of the heating element mount has a length that is greater than a width thereof, which is greater than a thickness thereof, and wherein the first and second sides of the elongate heating element are faces defined by the width and the length.

13. The heating element module according to claim 11, wherein the first and second projections extend from the first surface of the heating element mount for a distance of between 2 mm and 10 mm along the length of the elongate heating element.

14. The heating element module according to claim 11, wherein each of the first and second projections has a non-planar free surface.

15. The heating element module according to claim 14, wherein the non-planar free surface is spherical.

16. The heating element module according to claim 11, wherein the heating portion comprises a ceramic insulating substrate supporting tracks formed from an electrically conductive material.

17. The heating element module according to claim 11, further comprising electrical contacts configured to supply power to the heating portion, wherein the electrical contacts extend from a second surface of the heating element mount.

18. The heating element module according to claim 11, the elongate heating element further comprising a heater substrate, and the heating portion further comprising a first portion and a second portion configured such that, when an electrical current is passed through the heating portion, the first portion is heated to a higher temperature than the second portion, wherein the first portion of the heating portion is disposed on a heating area of the heater substrate, and the second portion of the heating portion is disposed on a holding area of the heater substrate, and wherein the heating element mount and the first and second projections are adjacent the holding area of the heater substrate.

19. The heating element module according to claim 18, wherein the second portion of the heating portion is longer than the first portion.

20. An aerosol-generating device, comprising: an elongate cavity configured to receive an aerosol-generating article; and a heating element module comprising: an elongate heating element having a heating portion, a heating element mount, wherein the elongate heating element extends substantially perpendicularly from a first surface of the heating element mount, and first and second projections extending substantially perpendicularly from the first surface of the heating element mount and abutting first and second sides of the elongate heating element, wherein the heating portion of the elongate heating element is configured to extend into the elongate cavity such that it is insertable into an aerosol-generating article received in the elongate cavity.

Description

[0063] The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

[0064] FIG. 1 shows a portion of an embodiment of an aerosol-generating device comprising a heating element module;

[0065] FIG. 2 shows a detailed plan view of a heating element component of the heating element module shown in FIG. 1;

[0066] FIG. 3 shows a detailed plan view of the heating element module shown in FIG. 1;

[0067] FIG. 4 shows a side view of the heating element module shown in FIG. 3;

[0068] FIG. 5 shows an end view of the heating element module shown in FIGS. 3 and 4; and

[0069] FIG. 6 shows a schematic of an aerosol-generating article of ruse in an aerosol-generating device.

[0070] FIG. 1 illustrates a portion of an embodiment of an aerosol-generating device 10 comprising a heating element module 100. The aerosol-generating device 10 is illustrated in engagement with an aerosol-generating article 20 for consumption of the aerosol-generating article 20 by a user.

[0071] The aerosol-generating device 10 comprises an elongated sheath 12 for receiving an aerosol-generating article 20 for consumption. A proximal end 13 of the sheath 12 is open to allow access to the aerosol-generating article 20. A distal end 14 of the sheath 14 is spanned by a heating element module 100 comprising a heating element 95. The heating element 95 is retained by a heating element mount 110 such that a heating portion of the heating element 95 is located within the sheath 12. The heating portion is positioned to engage with a distal end of the aerosol-generating article when the aerosol-generating article 20 is fully received within the sheath 12.

[0072] The heating element 95 is shaped in the form of a blade terminating in a point 91. That is, the heating element 95 has a length dimension that is greater than its width dimension, which is greater than its thickness dimension. First and second faces 97, 98 of the heating element 95 are defined by the width and length of the heating element. First and second projections 115, 116 extend upwardly from a first surface of the mount 110. These first and second projections 115, 116 respectively abut the first and second faces 97, 98 of the heating element 95. The projections 115,116 act to stabilise the heating element 95 against stresses caused by deflection and torsion of the heating element 95. Table 1.0 below shows the comparison of the deflection and force required for failure between a heating element without the stabilising projections and with the stabilising projections. The test utilises an Instron 5565 material testing system. The test machine is configured to apply a force perpendicular to the heating element, adjacent the point 91, using a wedge shaped test head. The test head is lowered at a rate of approximately 0.1 mm per minute, and the initial load applied to the heating portion was 0.1 N. As can be seen from the test data shown in Table 1.0, the test was repeated 5 times for each type of heating element. The heating element of the present invention is shown to have a greater resistance to force before failure, a reduction in the deflection, and a reduction in the flexural stress.

TABLE-US-00001 TABLE 1.0 Heating Fracture Flexural element Test Thickness Width force Deflection stress type no. (mm) (mm) (N) (mm) (Mpa) Heating 1 0.40 4.90 5.3 1.50 487 Element 2 0.38 4.86 5.4 1.50 554 with the 3 0.39 4.87 5.2 1.30 505 stabilising 4 0.40 4.78 5.4 1.30 508 projections 5 0.39 4.94 6.0 1.40 575 Average 0.39 4.87 5.5 1.40 526 STD 0.01 0.06 0.3 0.10 37 Heating 1 0.40 4.82 5.6 1.80 523 element 2 0.37 4.88 5.3 1.40 571 without the 3 0.37 4.92 5.2 1.50 556 stabilising 4 0.36 4.90 5.0 1.40 567 projections 5 0.37 4.88 5.0 1.30 539 Average 0.37 4.88 5.2 1.48 551 STD 0.02 0.04 0.2 0.19 20

[0073] The heating element comprises two heating portions 100 and 102. The heating portion 200 is adjacent the first and second projections 115, 116 has an electrical resistance less than the electrical resistance of the heating portion 202. In use, this means that the heating portion 202 is heated to a higher temperature than the heating portion 200, the current in each portion being the same.

[0074] The aerosol-generating device 10 comprises a power supply and electronics (not shown) that allow the heating element 95 to be actuated. Such actuation may be manually operated or may occur automatically in response to a user drawing on the aerosol-generating article.

[0075] An exemplary aerosol-generating article, as illustrated in FIG. 1, can be described as follows.

[0076] The article 20 comprises five elements, a rigid hollow tube 302, an aerosol-forming substrate 304, a hollow cellulose acetate tube 306, a transfer section 308, and a mouthpiece filter 310. These five elements are arranged sequentially and in coaxial alignment and are assembled by a cigarette paper 312 to form a rod. When assembled, the article 20 may be between 45 millimetres and 52 millimetres long, and has a diameter of 7.2 millimetres.

[0077] The rigid hollow tube 302 is a ceramic tube having a length of 7 millimetres.

[0078] The aerosol-forming substrate 304 is located downstream of the rigid hollow tube 302 and comprises a bundle of crimped cast-leaf tobacco wrapped in a filter paper. The cast-leaf tobacco includes additives, including glycerine as an aerosol-forming additive.

[0079] The cellulose acetate tube 306 is located immediately downstream of the aerosol-forming substrate 304 and is formed from cellulose acetate. The tube 306 defines an aperture having a diameter of 3.3 millimetres. One function of the tube 306 is to locate the aerosol-forming substrate 304 towards the distal end of the article 20 so that it can be contacted with a heating element. The tube 306 acts to prevent the aerosol-forming substrate 304 from being forced along the article 20 towards the mouth-end when a heating element is inserted.

[0080] The transfer section 308 comprises a thin-walled tube of 18 millimetres in length. The transfer section 308 allows volatile substances released from the aerosol-forming substrate 304 to pass along the article 20 towards the mouth end 20. The volatile substances may cool within the transfer section 308 to form an aerosol. An aerosol-cooling element, such as a crimped and gathered sheet of polylactic acid may be used instead of the transfer section.

[0081] The mouthpiece filter 310 is a conventional mouthpiece filter formed from cellulose acetate, tow and having a length of 7 millimetres.

[0082] The five elements identified above are assembled by being tightly wrapped within a cigarette paper 312. The paper in this specific embodiment is a standard cigarette paper having standard properties or classification. The paper in this specific embodiment is a conventional cigarette paper.

[0083] As the aerosol-generating article 20 is pushed into the sheath 12 the point 91 of the heating element 95 engages with the aerosol-forming substrate 304. By applying a force to the aerosol-generating article, the second heating portion 202 penetrates into the aerosol-forming substrate 304. When the aerosol-generating article 20 is properly engaged with the aerosol-generating device 10, the second heating portion 202 has been inserted into the aerosol-forming substrate 304. When the heating element 95 is actuated, the aerosol-forming substrate 30 is warmed and volatile substances are generated or evolved. As a user draws on the mouth end of the aerosol-generating article 20, air is drawn into the aerosol-generating article and the volatile substances condense to form an inhalable aerosol. This aerosol passes through the mouth-end 22 of the aerosol-generating article and into the user's mouth.

[0084] FIG. 2 illustrates a heating element 90 component of a heating element module 100 in greater detail. The heating element 90 is substantially blade-shaped. That is, the heating element has a length that in use extends along the longitudinal axis of an aerosol-generating article engaged with the heating element, a width and a thickness. The width is greater than the thickness. The heating element 90 terminates in a point or spike 91 for penetrating an aerosol-generating article 20. The heating element 90 comprises an electrically insulating substrate 92, which defines the shape of the heating element 90. The electrically insulating material may be, for example, alumina (Al2O3), stabilized zirconia (ZrO2). It will be apparent to one of ordinary skill in the art that the electrically insulating material may be any suitable electrically insulating material and that many ceramic materials are suitable for use as the electrically insulating substrate.

[0085] Tracks 93 of an electrically conductive material are plated on a surface of the insulating substrate 92. The tracks 93 are formed from a thin layer of platinum. Any suitable conductive material may be used for the tracks, and the list of suitable materials includes many metals, including gold, that are well known to the skilled person. One end of the tracks 93 is coupled to a power supply by a first contact 94, and the other end of the tracks 93 is coupled to a power supply by a second contact 96. When a current is passed through the tracks 93, resistive heating occurs. This heats the entire heating element 90 and the surrounding environment. When a current passing through the tracks 93 of the heating element 90 is switched off, there is no resistive heating and the temperature of the heating element 90 is swiftly lowered.

[0086] FIGS. 3, 4, and 5 illustrate a heating element module 100 comprising a heating element 90 mounted in a heating element mount 110. The heating element 90 is mounted through a polymeric mount 110. A heating portion 95 of the heating element 90 extends perpendicularly from a first surface 111 of the heating element mount 110. A rear portion of the heating element 90, including the electrical contacts 94, 96 extends perpendicularly from a second surface 112 of the mount 110. The mount 110 retains the heating element 90 firmly in place. Two dome-shaped projections extend perpendicularly from the first surface 111 of the mount 110. These projections abut first 97 and second 98 faces of the heating portion 95 of the heating element 90. When incorporated in an aerosol-generating device (for example as illustrated in FIG. 1) the heating element module locates the heating portion 95 of the heating element 90 within the sheath 12 for contact with an aerosol-generating article.

[0087] FIG. 6 illustrates an alternative heated aerosol-generating article 600 which may be used with the aerosol-generating device as described above. The aerosol-generating article 600 comprises four elements arranged in coaxial alignment: a rigid hollow tube 602, an aerosol-forming substrate 604, an aerosol-cooling element 606, and a mouthpiece 608. These four elements are arranged sequentially and are circumscribed by an outer wrapper 610 to form the heated aerosol-generating article 600. The aerosol-generating article 600 has a proximal or mouth end 612, which a user inserts into his or her mouth during use, and a distal end 614 located at the opposite end of the aerosol-generating article 600 to the mouth end 612.

[0088] The distal end 614 of the aerosol-generating article may also be described as the upstream end of the aerosol-generating article 600 and the mouth end 612 of the aerosol-generating article 600 may also be described as the downstream end of the aerosol-generating article 600. Elements of the aerosol-generating article 600 located between the mouth end 612 and the distal end 614 can be described as being upstream of the mouth end 612 or, alternatively, downstream of the distal end 614.

[0089] The rigid hollow tube 602 is located at the extreme distal or upstream end of the aerosol-generating article 600. In the article shown in FIG. 6, the rigid hollow tube 602 is a hollow ceramic tube. This rigid hollow tube 602 may protect the aerosol-forming substrate from flames applied to the distal end of the article 600, thereby providing a means of reducing the chance of inadvertent ignition.

[0090] In the article illustrated in FIG. 6, the aerosol-forming substrate 604 comprises a gathered sheet of crimped homogenised tobacco material circumscribed by a wrapper. The crimped sheet of homogenised tobacco material comprises comprising glycerine as an aerosol-former.

[0091] The aerosol-cooling element 606 is located immediately downstream of the aerosol-forming substrate 604 and abuts the aerosol-forming substrate 604. In use, volatile substances released from the aerosol-forming substrate 604 pass along the aerosol-cooling element 606 towards the mouth end 612 of the aerosol-generating article 600. The volatile substances may cool within the aerosol-cooling element 606 to form an aerosol that is inhaled by the user. In the article illustrated in FIG. 6, the aerosol-cooling element comprises a crimped and gathered sheet of polylactic acid circumscribed by a wrapper. The crimped and gathered sheet of polylactic acid defines a plurality of longitudinal channels that extend along the length of the aerosol-cooling element 606.

[0092] The mouthpiece 608 is located immediately downstream of the aerosol-cooling element 606 and abuts the aerosol-cooling element 606. In the article illustrated in FIG. 6, the mouthpiece 608 comprises a conventional cellulose acetate tow filter of low filtration efficiency.

[0093] To assemble the aerosol-generating article 600, the four elements described above are aligned and tightly wrapped within the outer wrapper 610. In some embodiments, a distal end portion of the outer wrapper 610 of the aerosol-generating article 600 may be circumscribed by a band of tipping paper.

[0094] The aerosol-generating article 600 illustrated in FIG. 6 is designed to engage with an aerosol-generating device comprising a heating element in order to be smoked or consumed by a user. In use, the heating element of the aerosol-generating device heats the aerosol-forming substrate 604 of the aerosol-generating article 600 to a sufficient temperature to form an aerosol, which is drawn downstream through the aerosol-generating article 600 and inhaled by the user.