U.S. patent application number 15/543431 was filed with the patent office on 2018-01-04 for aerosol-generating article with integral heating element.
This patent application is currently assigned to Philip Morris Products S.A.. The applicant listed for this patent is Philip Morris Products S.A.. Invention is credited to Rui Nuno BATISTA, Oleg MIRONOV, Julien PLOJOUX, Dani RUSCIO.
Application Number | 20180000157 15/543431 |
Document ID | / |
Family ID | 52396599 |
Filed Date | 2018-01-04 |
United States Patent
Application |
20180000157 |
Kind Code |
A1 |
BATISTA; Rui Nuno ; et
al. |
January 4, 2018 |
AEROSOL-GENERATING ARTICLE WITH INTEGRAL HEATING ELEMENT
Abstract
There is provided an aerosol-generating article including a
tobacco plug, a mouthpiece positioned downstream of the tobacco
plug, and a resistive heating element positioned within the tobacco
plug. The resistive heating element includes an upstream portion
protruding from an upstream end of the tobacco plug, wherein the
upstream portion of the resistive heating element includes at least
two heater electrical contacts configured to receive a supply of
electrical energy from at least two device electrical contacts when
the aerosol-generating article including the resistive heating
element is inserted into an aerosol-generating device.
Inventors: |
BATISTA; Rui Nuno; (Morges,
CH) ; MIRONOV; Oleg; (Neuchatel, CH) ;
PLOJOUX; Julien; (Geneva, CH) ; RUSCIO; Dani;
(Cressier, CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Philip Morris Products S.A. |
Neuchatel |
|
CH |
|
|
Assignee: |
Philip Morris Products S.A.
Neuchatel
CH
|
Family ID: |
52396599 |
Appl. No.: |
15/543431 |
Filed: |
January 22, 2016 |
PCT Filed: |
January 22, 2016 |
PCT NO: |
PCT/EP2016/051385 |
371 Date: |
July 13, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A24F 47/004 20130101;
A24F 47/008 20130101 |
International
Class: |
A24F 47/00 20060101
A24F047/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 28, 2015 |
EP |
15152940.1 |
Claims
1.-15. (canceled)
16. An aerosol-generating article, comprising: a tobacco plug; a
mouthpiece disposed downstream of the tobacco plug; and a resistive
heating element disposed within the tobacco plug and comprising an
upstream portion protruding from an upstream end of the tobacco
plug, the upstream portion of the resistive heating element
comprising at least two heater electrical contacts configured to
receive a supply of electrical energy from at least two device
electrical contacts when the aerosol-generating article comprising
the resistive heating element is inserted into an
aerosol-generating device.
17. The aerosol-generating article according to claim 16, wherein
the resistive heating element further comprises an electrically
resistive heating track disposed on an elongate electrically
insulating substrate, and wherein the electrically resistive
heating track is electrically connected to the at least two heater
electrical contacts.
18. The aerosol-generating article according to claim 17, wherein
the elongate electrically insulating substrate is shaped in the
form of one of a rod, a needle, a pin, a blade, or a cone.
19. The aerosol-generating article according to claim 17, wherein
an upstream portion of the resistive heating element comprises a
disc of electrically insulating material, wherein the disc
comprises a downstream face abutting an upstream end of the tobacco
plug, wherein the elongate electrically insulating substrate
extends downstream from the downstream face of the disc, and
wherein the disc further comprises an upstream face on which the at
least two heater electrical contacts are disposed.
20. The aerosol-generating article according to claim 19, wherein
the disc and the tobacco plug both have a substantially circular
cross-sectional shape, and wherein a diameter of the disc is
substantially the same as a diameter of the tobacco plug.
21. The aerosol-generating article according to claim 16, further
comprising an article securing element configured to interact with
a device securing element on the aerosol-generating device to
releasably retain the aerosol-generating article within the
aerosol-generating device.
22. The aerosol-generating article according to claim 16, wherein
at least one of the at least two heater electrical contacts and/or
at least one of the at least two device electrical contacts
comprises a magnetized material configured to releasably retain the
at least two heater electrical contacts in electrical contact with
corresponding device electrical contacts when the
aerosol-generating article is inserted into the aerosol-generating
device.
23. The aerosol-generating article according to claim 16, wherein
the aerosol-generating article has a substantially circular
cross-sectional shape centered on a longitudinal axis of the
aerosol-generating article, wherein the at least two heater
electrical contacts comprise a first heater electrical contact
having an annular shape centered on the longitudinal axis of the
aerosol-generating article and a second heater electrical contact
having a circular or an annular shape centered on the longitudinal
axis of the aerosol-generating article, wherein an outer diameter
of the second heater electrical contact is smaller than an inner
diameter of the first heater electrical contact, and wherein the
second heater electrical contact is disposed within the first
heater electrical contact.
24. An electrically heated aerosol-generating system, comprising:
an aerosol-generating article comprising: a tobacco plug, a
mouthpiece disposed downstream of the tobacco plug, and a resistive
heating element disposed within the tobacco plug and comprising an
upstream portion protruding from an upstream end of the tobacco
plug, the upstream portion of the resistive heating element
comprising at least two heater electrical contacts; and an
aerosol-generating device comprising: a tubular housing comprising
a cavity configured to receive at least an upstream portion of the
aerosol-generating article, a supply of electrical energy within
the tubular housing, and at least two device electrical contacts
connected to the supply of electrical energy, wherein the at least
two device electrical contacts are disposed at an upstream end of
the cavity and are configured to contact the at least two heater
electrical contacts when the aerosol-generating article is inserted
into the cavity to transfer electrical energy from the supply of
electrical energy to the resistive heating element, and wherein the
at least two heater electrical contacts are configured to receive a
supply of electrical energy from at least two device electrical
contacts when the aerosol-generating article comprising the
resistive heating element is inserted into the aerosol-generating
device.
25. The electrically heated aerosol-generating system according to
claim 24, wherein the at least two device electrical contacts
comprise a first device electrical contact spaced apart from a
second device electrical contact, wherein the aerosol-generating
article has a substantially circular cross-sectional shape centered
on a longitudinal axis of the aerosol-generating article, wherein
the at least two heater electrical contacts comprise a first heater
electrical contact having an annular shape centered on the
longitudinal axis of the aerosol-generating article and a second
heater electrical contact having a circular or an annular shape
centered on the longitudinal axis of the aerosol-generating
article, wherein an outer diameter of the second heater electrical
contact is smaller than an inner diameter of the first heater
electrical contact, and wherein the second heater electrical
contact is disposed within the first heater electrical contact.
26. A method of manufacturing an aerosol-generating article,
comprising: providing a tobacco plug and a mouthpiece; wrapping a
wrapper around at least a portion of the tobacco plug and the
mouthpiece to secure the mouthpiece to a downstream end of the
tobacco plug; providing a resistive heating element comprising an
electrically resistive heating track on an elongate electrically
insulating substrate, and at least two heater electrical contacts
configured to receive a supply of electrical energy and being
connected to the electrically resistive heating track; and
inserting at least a portion of the elongate electrically
insulating substrate into the tobacco plug at an upstream end of
the tobacco plug, the upstream portion of the resistive heating
element protruding from the upstream end of the tobacco plug,
wherein the upstream portion of the resistive heating element
comprises the at least two heater electrical contacts configured to
receive the supply of electrical energy.
27. The method according to claim 26, wherein the elongate
electrically insulating substrate is shaped in the form of one of a
rod, a needle, a pin, a blade, or a cone, and wherein the step of
inserting at least the portion of the elongate electrically
insulating substrate into the tobacco plug further comprises
inserting the rod, the needle, the pin, the blade, or the cone into
the tobacco rod.
28. The method according to claim 26, wherein the upstream portion
of the resistive heating element comprises a disc of electrically
insulating material, wherein the disc comprises an upstream face on
which the at least two heater electrical contacts are disposed and
a downstream face from which the electrically insulating substrate
extends, and wherein the step of inserting at least the portion of
the elongate electrically insulating substrate into the tobacco
plug further comprises inserting the elongate electrically
insulating substrate until the downstream face of the disc abuts
the upstream end of the tobacco plug.
29. The method according to claim 28, wherein the disc and the
tobacco plug both have a substantially circular cross-sectional
shape, and wherein a diameter of the disc is substantially the same
as a diameter of the tobacco plug.
30. The A method of manufacturing a tobacco plug, comprising:
positioning a resistive heating element on a forming belt, the
resistive heating element comprising at least two heater electrical
contacts configured to receive a supply of electrical energy;
depositing a tobacco shiny onto the forming belt; drying the
tobacco slurry to form a dried tobacco sheet comprising the
resistive heating element; and forming the dried tobacco sheet
comprising the resistive heating element into a tobacco plug, the
resistive heating element positioned within the tobacco plug and
comprising an upstream portion protruding from an upstream end of
the tobacco plug, wherein the upstream portion of the resistive
heating element comprises the least two heater electrical contacts
configured to receive the supply of electrical energy.
Description
[0001] The present invention relates to an aerosol-generating
article having an integrated heating element. The present invention
also relates to an electrically heated aerosol-generating system
comprising an aerosol-generating article having an integrated
heating element, and to methods of manufacturing tobacco plugs and
aerosol-generating articles each having an integrated heating
element.
[0002] One type of aerosol-generating system is an electrically
operated smoking system. Known handheld electrically operated
smoking systems typically comprise an aerosol-generating device
comprising a battery, control electronics and an electric heater
for heating a smoking article designed specifically for use with
the aerosol-generating device. In some examples, the smoking
article comprises a plug of an aerosol-forming substrate, such as a
tobacco plug, and the heater contained within the
aerosol-generating device is inserted into the aerosol-forming
substrate when the smoking article is inserted into the
aerosol-generating device. However, the electric heater may become
contaminated with material from the aerosol-forming substrate
during use and cleaning the electric heater inside the device can
be difficult. In some cases, it may be necessary to dispose of the
entire device if the heater cannot be adequately cleaned. Sometimes
removal of the smoking article from the device is also difficult,
which may result in the need for a dedicated extraction tool to
facilitate removal of the smoking article from the device without
damaging the heater.
[0003] Accordingly, it would be desirable to produce an
aerosol-generating article and an electrically heated
aerosol-generating system that address the issue of heater
contamination and the difficulty in extracting the article from an
aerosol-generating device.
[0004] According to a first aspect of the present invention there
is provided an aerosol-generating article comprising a tobacco
plug, a mouthpiece positioned downstream of the tobacco plug, and a
resistive heating element positioned within the tobacco plug. The
resistive heating element comprises an upstream portion protruding
from an upstream end of the tobacco plug, wherein the upstream
portion of the resistive heating element comprises at least two
heater electrical contacts for receiving a supply of electrical
energy from at least two device electrical contacts when the
aerosol-generating article comprising the resistive heating element
is inserted into an aerosol-generating device.
[0005] As used herein, the term "aerosol-generating article" refers
to an article comprising a tobacco plug that, when heated, releases
volatile compounds that can form an aerosol.
[0006] As used herein, the term "aerosol-generating device" refers
to a device that interacts with an aerosol-generating article to
generate an aerosol. The aerosol-generative device includes a
supply of electrical energy to operate the resistive heating
element within the aerosol-generating article.
[0007] As used herein, the terms "upstream" and "downstream" are
used to describe the relative positions of components, or portions
of components, of aerosol-generating articles according to the
invention with respect to the direction of airflow through the
aerosol-generating article when a user draws on the
aerosol-generating article. In particular, when a user draws on the
article, air flows in the downstream direction from the upstream
end to the downstream end.
[0008] By providing a resistive heating element as part of the
aerosol-generating article, rather than part of an
aerosol-generating device, the present invention addresses at least
some of the issues associated with known electrically heated
aerosol-generating systems. In particular, providing the
aerosol-generating article with an integrated resistive heating
element eliminates the need to remove contamination from a heating
element contained within an aerosol-generating device, as is the
case with known electrically heated aerosol-generating systems in
which the heater is a reusable heater fixed within an
aerosol-generating device. Providing the resistive heating element
in the aerosol-generating article can also make it easier to remove
the article from an aerosol-generating device when compared to
known electrically heated aerosol-generating systems in which a
fixed heating element within the device can make it difficult to
remove the article without the use of a dedicated extraction
tool.
[0009] In some embodiments, the resistive heating element may
comprise an electrically resistive heating track provided on an
elongate electrically insulating substrate, and wherein the
electrically resistive heating track is electrically connected to
the at least two heater electrical contacts. Providing an
electrically resistive heating track on an electrically insulating
substrate can simplify the manufacture of the aerosol-generating
article by facilitating separate manufacture of the resistive
heating element, which can then be inserted into the tobacco plug
after the remainder of the aerosol-generating article has been
constructed.
[0010] The resistive heating element may be provided to a consumer
separately from the remainder of the aerosol-generating article so
that the consumer can insert the resistive heating element into the
tobacco plug. This arrangement is particularly useful in
embodiments in which the resistive heating element is reusable with
a plurality of aerosol-generating articles. Alternatively, a
resistive heating element may be inserted into each tobacco plug
during the manufacture of the aerosol-generating articles.
[0011] To facilitate the insertion of the resistive heating element
into the tobacco plug, the elongate electrically insulating
substrate is preferably shaped in the form of one of a rod, a
needle, a pin, a blade, or a cone. Additionally, or alternatively,
the elongate electrically insulating substrate may comprise one or
more serrated edges, wherein the serrations are shaped to favour
insertion of the resistive heating element into the tobacco plug
and resist removal of the resistive heating element from the
tobacco plug. Providing such serrated edges can advantageously
prevent the resistive heating element from becoming dislodged from
the tobacco plug when the aerosol-generating article is removed
from an aerosol-generating device.
[0012] In alternative embodiments, the elongate electrically
insulating substrate may have a helical shape so that the resistive
heating element can be screwed into and out of the tobacco plug but
cannot be pushed directly into or pulled directly out of the
tobacco plug. Utilising a helical shape can therefore prevent the
resistive heating element from becoming dislodged from the tobacco
plug when the aerosol-generating article is removed from an
aerosol-generating device.
[0013] In those embodiments in which a resistive heating element is
inserted into each tobacco plug during the manufacture of
aerosol-generating articles according to the present invention, the
resistive heating element is typically disposable with the
remainder of the aerosol-generating article. In such embodiments,
the resistive heating element is preferably constructed from
low-cost materials, such as low cost metals and metal alloys.
[0014] Alternatively, the resistive heating element may be reusable
with multiple aerosol-generating articles. For example, a pack of
aerosol-generating articles may be provided with a single resistive
heating element, wherein the resistive heating element is removed
from the tobacco plug of each aerosol-generating article after it
has been smoked and inserted into the next aerosol-generating
article. In such embodiments, it may be cost-effective to
manufacture the resistive heating element from more expensive
materials. For example, reusable resistive heating elements may
comprise an elongate electrically insulating substrate formed from
a non-conductive ceramic.
[0015] Preferably, the electrically insulating substrate is
operable at a working temperature of up to about 700 degrees
Celsius, more preferably about 800 degrees Celsius. Additionally,
or alternatively, the operating temperature of the resistive
heating element during use may be about 250 degrees Celsius, more
preferably about 300 degrees Celsius.
[0016] Suitable materials for forming the electrically resistive
heating track include but are not limited to: semiconductors such
as doped ceramics, electrically "conductive" ceramics (such as, for
example, molybdenum disilicide), carbon, graphite, metals, metal
alloys and composite materials made of a ceramic material and a
metallic material. Such composite materials may comprise doped or
undoped ceramics. Examples of suitable doped ceramics include doped
silicon carbides. Examples of suitable metals include titanium,
zirconium, tantalum and metals from the platinum group. Examples of
suitable metal alloys include stainless steel, nickel-, cobalt-,
chromium-, aluminium- titanium- zirconium-, hafnium-, niobium-,
molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese- and
iron-containing alloys, and super-alloys based on nickel, iron,
cobalt, stainless steel, Timetal.RTM. and iron-manganese-aluminium
based alloys.
[0017] In some embodiments, the electrically resistive heating
track comprises one or more stamped portions of electrically
resistive material, such as stainless steel. Alternatively, the
electrically resistive heating track may comprise a heating wire or
filament, for example a Ni--Cr (Nickel-Chromium), platinum,
tungsten or alloy wire.
[0018] In any of those embodiments in which the resistive heating
element comprises an electrically resistive heating track provided
on an elongate electrically insulating substrate, the upstream
portion of the resistive heating element may comprises a disc of
electrically insulating material, wherein the disc comprises a
downstream face abutting an upstream end of the tobacco plug,
wherein the elongate electrically insulating substrate extends
downstream from the downstream face of the disc, and wherein the
disc further comprises an upstream face on which the at least two
heater electrical contacts are provided.
[0019] Providing the resistive heating element with a disc of
electrically insulating material at its upstream end advantageously
facilitates insertion of the resistive heating element into the
tobacco plug in those embodiments in which the resistive heating
element is inserted into the tobacco plug after the tobacco plug
has been formed. Specifically, the elongate electrically insulating
substrate can be sized so that when the resistive heating element
is inserted into the tobacco plug so that the downstream face of
the disc of electrically insulating material abuts the upstream end
of the tobacco plug the elongate electrically insulating substrate,
and therefore the resistive heating track, are correctly positioned
within the tobacco plug.
[0020] Advantageously, the upstream face of the disc of
electrically insulating material also provides a large surface area
on which the at least two heater electrical contacts can be
provided, which facilitates the manufacture of the resistive
heating element.
[0021] The disc of electrically insulating material may be formed
from the same insulating material as the elongate electrically
insulating substrate, or they may be formed from different
materials.
[0022] Preferably, the disc of electrically insulating material and
the elongate electrically insulating substrate are formed from the
same material. To simplify the manufacture of the resistive heating
element, the disc of electrically insulating material and the
elongate electrically insulating substrate are preferably
integrally formed from a single piece of electrically insulating
material. For example, the resistive heating element may formed by
moulding or otherwise casting an electrically insulating material
around the electrically resistive heating track.
[0023] In any of those embodiments in which the resistive heating
element comprises a disc of electrically insulating material, the
disc and the tobacco plug preferably both have a substantially
circular cross-sectional shape, wherein the diameter of the disc is
substantially the same as the diameter of the tobacco plug. This
advantageously facilitates correct insertion of the resistive
heating element into the tobacco plug. For example, in those
embodiments in which a resistive heating element is inserted into
each tobacco plug during the manufacture of the aerosol-generating
articles, a tubular guide may be used to ensure that the disc of
electrically insulating material is positioned coaxially with the
tobacco plug.
[0024] In any of the embodiments described above, the
aerosol-generating article preferably further comprises an article
securing element configured to interact with a device securing
element on an aerosol-generating device to releasably retain the
aerosol-generating article within the aerosol-generating device. By
releasably retaining the aerosol-generating article within the
aerosol-generating device the article securing element can
advantageously ensure that a reliable electrical contact is
maintained between the heater electrical contacts and corresponding
device electrical contacts in the aerosol-generating device during
heating of the aerosol-generating article.
[0025] The article securing element is preferably configured so
that forces exerted on the aerosol-generating article during normal
use of an electrically heated aerosol-generating system comprising
the aerosol-generating article inserted into an aerosol-generating
device are insufficient to break the electrical contact between the
heater electrical contacts and device electrical contacts, while
also being configured so that a consumer can easily remove the
aerosol-generating article, including the resistive heating
element, from the aerosol-generating device. For example, the
resistive heater element may comprise a magnetised material
provided at an upstream end of the resistive heater element,
wherein the magnetised material interacts with a magnetised
material or a non-magnetised but ferromagnetic material provided
within the aerosol-generating device. In a particularly preferred
embodiment, at least one of the heater electrical contacts
comprises a magnetised material, wherein the at least one heater
electrical contact comprising a magnetised material is magnetically
attracted to the corresponding at least one device electrical
contact to releasably retain the heater electrical contacts in
electrical contact with the corresponding device electrical
contacts when the aerosol-generating article is inserted into the
aerosol-generating device. In such embodiments, the article
securing element comprises the at least one heater electrical
contact comprising a magnetised material. The one or more device
electrical contacts corresponding to the at least one heater
electrical contact comprising a magnetised material may also
comprise a magnetised material. Alternatively, the one or more
device electrical contacts corresponding to the at least one heater
electrical contact comprising a magnetised material may comprise a
non-magnetised but ferromagnetic material.
[0026] In an alternative embodiment, at least one of the device
electrical contacts comprises a magnetised material, wherein the at
least one device electrical contact comprising a magnetised
material is magnetically attracted to the corresponding at least
one heater electrical contact to releasably retain the heater
electrical contacts in electrical contact with the corresponding
device electrical contacts when the aerosol-generating article is
inserted into the aerosol-generating device. In such embodiments,
the device securing element comprises the at least one device
electrical contact comprising a magnetised material and the article
securing element comprises the one or more corresponding heater
electrical contacts. The one or more heater electrical contacts
corresponding to the at least one device electrical contact
comprising a magnetised material may also comprise a magnetised
material. Alternatively, the one or more heater electrical contacts
corresponding to the at least one device electrical contact
comprising a magnetised material may comprise a non-magnetised but
ferromagnetic material.
[0027] In further alternative embodiments, the article and device
securing elements may interact mechanically to retain the
aerosol-generating article within the aerosol-generating device.
For example, the aerosol-generating device may comprise a tapered
cavity into which the aerosol-generating article is received, the
tapered cavity providing an interference fit between the tapered
surface of the cavity and the outer surface of the
aerosol-generating article. In such embodiments, the cavity forms
the device securing element and the outer surface of the
aerosol-generating article forms the article securing element.
Alternatively, a different mechanical interaction may be provided
between the aerosol-generating article and the aerosol-generating
device. For example, the aerosol-generating article may comprise a
male portion of a bayonet connection that interacts with a
corresponding female portion of a bayonet connection provided
within the aerosol-generating device. In such embodiments, the male
and female portions of the bayonet connection form the article and
device securing elements respectively. In those embodiments in
which the resistive heating element comprises a disc of
electrically insulating material the male portion of the bayonet
connection is preferably provided by the disc of electrically
insulating material.
[0028] In any of the embodiments described above, the
aerosol-generating article may have a substantially circular
cross-sectional shape. In such embodiments, the at least two heater
electrical contacts may comprise a first heater electrical contact
spaced apart from a second heater electrical contact, wherein the
aerosol-generating article further comprises an indexing indicator
to indicate the rotational orientation of the aerosol-generating
article. Providing an indexing indicator on the aerosol-generating
article advantageously assists the consumer in inserting the
aerosol-generating article into an aerosol-generating device in the
correct orientation so that the at least two heater electrical
contacts are aligned with and contact corresponding device
electrical contacts as may be provided inside the
aerosol-generating device.
[0029] For example, the aerosol-generating article may comprise a
shaped portion, such as a raised portion or an indentation, which
forms the indexing indicator. In such embodiments, the indexing
indicator may cooperate with a correspondingly shaped portion on an
aerosol-generating device. For example, the aerosol-generating
article may comprise a groove in an outer surface of the article
which must be aligned with a correspondingly shaped ridge on an
interior surface of an aerosol-generating device to allow insertion
of the article into the device.
[0030] Additionally, or alternatively, the indexing indicator may
comprise one or more indicia provided on an outer surface of the
aerosol-generating article, which must be aligned with a
corresponding indicia provided on an aerosol-generating device. In
such embodiments, at least one indicia is preferably provided at
the downstream end of the aerosol-generating article so that it
remains visible to the consumer when the aerosol-generating article
has been inserted into an aerosol-generating device.
[0031] In alternative embodiments, the aerosol-generating article
may have a substantially circular cross-sectional shape centred on
a longitudinal axis of the aerosol-generating article, wherein the
at least two heater electrical contacts comprise a first heater
electrical contact having an annular shape centred on the
longitudinal axis of the aerosol-generating article and a second
heater electrical contact having a circular or an annular shape
centred on the longitudinal axis of the aerosol-generating article.
An outer diameter of the second heater electrical contact is
smaller than an inner diameter of the first heater electrical
contact, and the second heater electrical contact is positioned
within the first heater electrical contact.
[0032] Advantageously, forming a first of the heater electrical
contacts as an annular contact with the second heater contact
coaxially positioned within the first heater electrical contact and
on the longitudinal axis of the aerosol-generating article provides
a heater electrical contact configuration that is independent of
the rotational orientation of the aerosol-generating article.
Therefore, in such embodiments, an indexing indicator may not be
required as the correct contact between the heater electrical
contacts and device electrical contacts in an aerosol-generating
device may be achieved with any rotational orientation of the
article with respect to the device.
[0033] In any of the embodiments described above, the
aerosol-generating article may further comprise an article data
storage device for storing data indicative of the type of
aerosol-generating article. Additionally, or alternatively, the
article data storage device may store data relating to a heating
profile for the aerosol-generating article.
[0034] In those embodiments in which the aerosol-generating article
comprises an article data storage device, the aerosol-generating
article preferably further comprises one or more article data
electrical contacts for connecting to one or more device data
electrical contacts on an aerosol-generating device.
[0035] At least one of the article data storage device and the
article data electrical contacts may be configured so that the
article data storage device can be accessed only in a read-only
mode.
[0036] For example, the article data storage device may communicate
the type of aerosol-generating article to an aerosol-generating
device via the article data electrical contacts and device data
electrical contacts so that the aerosol-generating device can
select the appropriate heating profile from one or more heating
profiles stored within a device data storage device. Alternatively,
the article data storage device may communicate an appropriate
heating profile to an aerosol-generating device via the article
data electrical contacts and device data electrical contacts.
[0037] Alternatively, at least one of the article data storage
device and the article data electrical contacts may be configured
so that the article data storage device can be accessed in a
read-write mode. For example, an aerosol-generating device may read
at least one of the type of aerosol-generating article and an
appropriate heating profile from the article data storage device,
as described above. Additionally, or alternatively, an
aerosol-generating device may write data to the article data
storage device. For example, an aerosol-generating device may write
data to the article data storage device to indicate that the
aerosol-generating article has been smoked. If the smoked
aerosol-generating article is then re-inserted into an
aerosol-generating device, the aerosol-generating device may read
the data from the article data storage device indicative of the
aerosol-generating article having been smoked and therefore prevent
the article being smoked again.
[0038] In those embodiments in which the aerosol-generating article
comprises an article data storage device, the article data storage
device is preferably provided on or otherwise formed integrally
with the resistive heating element. For example, in those
embodiments in which the resistive heating element comprises a disc
of electrically insulting material, the article data storage device
is preferably provided on or within the disc of electrically
insulating material. Similarly, in those embodiments in which the
aerosol-generating article comprises one or more article data
electrical contacts, the article data electrical contacts are
preferably provided on the upstream face of the disc of
electrically insulating material.
[0039] In any of the embodiments described above, the tobacco plug
may comprise at least one an aerosol former, that is, a substance
which generates an aerosol upon heating. The aerosol former may be,
for instance, a polyol aerosol former or a non-polyol aerosol
former. It may be a solid or liquid at room temperature. Suitable
polyols include sorbitol, glycerol, and glycols like propylene
glycol or triethylene glycol. Suitable non-polyols include
monohydric alcohols, such as menthol, high boiling point
hydrocarbons, acids such as lactic acid, and esters such as
diacetin, triacetin, triethyl citrate or isopropyl myristate.
Aliphatic carboxylic acid esters such as methyl stearate, dimethyl
dodecanedioate and dimethyl tetradecanedioate can also be used as
aerosol formers. A combination of aerosol formers may be used, in
equal or differing proportions. Polyethylene glycol and glycerol
may be particularly preferred, whilst triacetin is more difficult
to stabilise and may also need to be encapsulated in order to
prevent its migration within the article. The at least one
aerosol-forming substrate may include one or more flavouring
agents, such as cocoa, liquorice, organic acids, or menthol.
[0040] The tobacco plug may comprise one or more of: powder,
granules, pellets, shreds, spaghettis, strips or sheets containing
one or more of: tobacco leaf, fragments of tobacco ribs,
reconstituted tobacco, homogenised tobacco, extruded tobacco and
expanded tobacco. Optionally, the tobacco plug may contain
additional tobacco or non-tobacco volatile flavour compounds, to be
released upon heating of the tobacco plug. Optionally, the tobacco
plug may also contain capsules that, for example, include the
additional tobacco or non-tobacco volatile flavour compounds. Such
capsules may melt during heating of the tobacco plug.
Alternatively, or in addition, such capsules may be crushed prior
to, during, or after heating of the tobacco plug.
[0041] Where the tobacco plug comprises homogenised tobacco
material, the homogenised tobacco material may be formed by
agglomerating particulate tobacco. The homogenised tobacco material
may be in the form of a sheet. The homogenised tobacco material may
have an aerosol-former content of greater than 5 percent on a dry
weight basis. The homogenised tobacco material may alternatively
have an aerosol former content of between 5 percent and 30 percent
by weight on a dry weight basis. Sheets of homogenised tobacco
material may be formed by agglomerating particulate tobacco
obtained by grinding or otherwise comminuting one or both of
tobacco leaf lamina and tobacco leaf stems; alternatively, or in
addition, sheets of homogenised tobacco material may comprise one
or more of tobacco dust, tobacco fines and other particulate
tobacco by-products formed during, for example, the treating,
handling and shipping of tobacco. Sheets of homogenised tobacco
material may comprise one or more intrinsic binders, that is
tobacco endogenous binders, one or more extrinsic binders, that is
tobacco exogenous binders, or a combination thereof to help
agglomerate the particulate tobacco. Alternatively, or in addition,
sheets of homogenised tobacco material may comprise other additives
including, but not limited to, tobacco and non-tobacco fibres,
aerosol-formers, humectants, plasticisers, flavourants, fillers,
aqueous and non-aqueous solvents and combinations thereof. Sheets
of homogenised tobacco material are preferably formed by a casting
process of the type generally comprising casting a slurry
comprising particulate tobacco and one or more binders onto a
conveyor belt or other support surface, drying the cast slurry to
form a sheet of homogenised tobacco material and removing the sheet
of homogenised tobacco material from the support surface.
[0042] The aerosol-generating article may have a total length of
between approximately 30 millimetres and 100 millimetres. The
aerosol-generating article may have an external diameter of between
approximately 5 millimetres and approximately 13 millimetres.
[0043] The mouthpiece may be located at the downstream end of the
aerosol-generating article. The mouthpiece may be a cellulose
acetate filter plug. The mouthpiece is preferably approximately 7
millimetres in length, but can have a length of between
approximately 5 millimetres to approximately 10 millimetres.
[0044] The tobacco plug may have a length of approximately 10
millimetres. However it is most preferable for the tobacco plug to
have a length of 12 millimetres.
[0045] The diameter of the tobacco plug may be between
approximately 5 millimetres and approximately 12 millimetres.
[0046] Preferably, the aerosol-generating article is a cigarette.
In a preferred embodiment, the aerosol-generating article has a
total length between 40 millimetres and 50 millimetres.
[0047] Preferably, the aerosol-generating article has a total
length of approximately 45 millimetres. It is also preferable for
the aerosol-generating article to have an external diameter of
approximately 7.2 millimetres.
[0048] The present invention also extends to electrically heated
aerosol-generating systems comprising the aerosol-generating
article described above. Therefore, according to a second aspect of
the present invention there is provided an electrically heated
aerosol-generating system comprising an aerosol-generating article
according to the first aspect of the present invention, in
accordance with any of the embodiments described above, and an
aerosol-generating device. The aerosol-generating device comprises
a tubular housing comprising a cavity for receiving at least an
upstream portion of the aerosol-generating article. The
aerosol-generating device also comprises a supply of electrical
energy within the tubular housing, and at least two device
electrical contacts connected to the supply of electrical energy.
The at least two device electrical contacts are positioned at an
upstream end of the cavity and configured to contact the at least
two heater electrical contacts when the aerosol-generating article
is inserted into the cavity to transfer electrical energy from the
supply of electrical energy to the resistive heating element.
[0049] In some embodiments, the aerosol-generating article and the
cavity may both have a substantially circular cross-sectional
shape. In such embodiments, the at least two heater electrical
contacts may comprise a first heater electrical contact spaced
apart from a second heater electrical contact, and the at least two
device electrical contacts may comprise a first device electrical
contact spaced apart from a second device electrical contact. The
aerosol-generating article and the aerosol-generating device may
each comprise an indexing indicator to indicate the rotational
orientation of the aerosol-generating article with respect to the
aerosol-generating device when the aerosol-generating article is
received within the cavity. As described above, providing an
indexing indicator on each of the aerosol-generating article and
the aerosol-generating device advantageously assists the consumer
in inserting the aerosol-generating article into the
aerosol-generating device in the correct orientation so that the at
least two heater electrical contacts are aligned with and contact
the corresponding device electrical contacts.
[0050] In any of the embodiments described above in which the
aerosol-generating article comprises an article securing element,
the aerosol-generating device preferably comprises a device
securing element configure to interact with the article securing
element to releasably retain the aerosol-generating article within
the aerosol-generating device. By releasably retaining the
aerosol-generating article within the aerosol-generating device the
article securing element and the device securing element can
advantageously ensure that a reliable electrical contact is
maintained between the heater electrical contacts and the
corresponding device electrical contacts during heating of the
aerosol-generating article.
[0051] The article securing element and the device securing element
are preferably configured so that forces exerted on the
aerosol-generating article during normal use of the electrically
heated aerosol-generating system are insufficient to break the
electrical contact between the heater electrical contacts and the
device electrical contacts, while also being configured so that a
consumer can easily remove the aerosol-generating article,
including the resistive heating element, from the
aerosol-generating device. For example, the resistive heater
element may comprise a magnetised material provided at an upstream
end of the resistive heater element, wherein the magnetised
material interacts with a magnetised material or a non-magnetised
but ferromagnetic material provided within the aerosol-generating
device. Alternatively, the aerosol-generating device may comprise a
magnetised material configured to interact with a magnetised
material or a non-magnetised but ferromagnetic material provided at
an upstream end of the resistive heater element.
[0052] In a preferred embodiment, at least one of the heater
electrical contacts comprises a magnetised material, wherein the at
least one heater electrical contact comprising a magnetised
material is magnetically attracted to the corresponding at least
one device electrical contact to releasably retain the heater
electrical contacts in electrical contact with the corresponding
device electrical contacts when the aerosol-generating article is
inserted into the aerosol-generating device. In such embodiments,
the article securing element comprises the at least one heater
electrical contact comprising a magnetised material and the device
securing element comprises the one or more corresponding device
electrical contacts. The one or more device electrical contacts
corresponding to the at least one heater electrical contact
comprising a magnetised material may also comprise a magnetised
material. Alternatively, the one or more device electrical contacts
corresponding to the at least one heater electrical contact
comprising a magnetised material may comprise a non-magnetised but
ferromagnetic material.
[0053] In an alternative embodiment, at least one of the device
electrical contacts comprises a magnetised material, wherein the at
least one device electrical contact comprising a magnetised
material is magnetically attracted to the corresponding at least
one heater electrical contact to releasably retain the heater
electrical contacts in electrical contact with the corresponding
device electrical contacts when the aerosol-generating article is
inserted into the aerosol-generating device. In such embodiments,
the device securing element comprises the at least one device
electrical contact comprising a magnetised material and the article
securing element comprises the one or more corresponding heater
electrical contacts. The one or more heater electrical contacts
corresponding to the at least one device electrical contact
comprising a magnetised material may also comprise a magnetised
material. Alternatively, the one or more heater electrical contacts
corresponding to the at least one device electrical contact
comprising a magnetised material may comprise a non-magnetised but
ferromagnetic material.
[0054] In further alternative embodiments, the article and device
securing elements may interact mechanically to retain the
aerosol-generating article within the aerosol-generating device.
For example, the cavity into which the aerosol-generating article
is received may be tapered, the tapered cavity providing an
interference fit between the tapered surface of the cavity and the
outer surface of the aerosol-generating article. In such
embodiments, the cavity forms the device securing element and the
outer surface of the aerosol-generating article forms the article
securing element. Alternatively, a different mechanical interaction
may be provided between the aerosol-generating article and the
aerosol-generating device. For example, the aerosol-generating
article may comprise a male portion of a bayonet connection that
interacts with a corresponding female portion of a bayonet
connection provided within the aerosol-generating device. In such
embodiments, the male and female portions of the bayonet connection
form the article and device securing elements respectively. In
those embodiments in which the resistive heating element comprises
a disc of electrically insulating material the male portion of the
bayonet connection is preferably provided by the disc of
electrically insulating material.
[0055] For example, the aerosol-generating article may comprise a
shaped portion, such as a raised portion or an indentation, which
forms an indexing indicator on the aerosol-generating article that
cooperates with a correspondingly shaped indexing indicator on the
aerosol-generating device. For example, the aerosol-generating
article may comprise a groove in an outer surface of the article
which must be aligned with a correspondingly shaped ridge on the
interior surface of the cavity to allow insertion of the article
into the cavity
[0056] Alternatively, the at least two device electrical contacts
may comprise a first device electrical contact spaced apart from a
second device electrical contact, wherein the aerosol-generating
article has a substantially circular cross-sectional shape centred
on a longitudinal axis of the aerosol-generating article, and
wherein the at least two heater electrical contacts comprise a
first heater electrical contact having an annular shape centred on
the longitudinal axis of the aerosol-generating article and a
second heater electrical contact having a circular or an annular
shape centred on the longitudinal axis of the aerosol-generating
article. The outer diameter of the second heater electrical contact
is smaller than an inner diameter of the first heater electrical
contact, and the second heater electrical contact is positioned
within the first heater electrical contact.
[0057] As described above, forming a first of the heater electrical
contacts as an annular contact with the second heater contact
coaxially positioned within the first heater electrical contact and
on the longitudinal axis of the aerosol-generating article
advantageously provides a heater electrical contact configuration
that is independent of the rotational orientation of the
aerosol-generating article. Therefore, in such embodiments, an
indexing indicator may not be required as the correct contact
between the heater electrical contacts and the device electrical
contacts in the aerosol-generating device may be achieved with any
rotational orientation of the article with respect to the device,
providing one of the device electrical contacts is centred on a
longitudinal axis of the cavity and the spacing between the first
and second device electrical contacts is the same as the spacing
between the first and second heater electrical contacts. In some
embodiments, the first and second device electrical contacts may
have the same configuration as the heater electrical contacts. That
is, the first device electrical contact may be an annular
electrical contact surrounding the second device electrical
contact.
[0058] In alternative embodiments, the first device electrical
contact may be an annular electrical contact surrounding the second
device electrical contact, both centred on the longitudinal axis of
the cavity, and the first and second heater electrical contacts may
have any configuration, providing one of the heater electrical
contacts is centred on the longitudinal axis of the
aerosol-generating article and the spacing between the first and
second heater electrical contacts is the same as the spacing
between the first and second device electrical contacts. Such a
configuration still permits insertion of the aerosol-generating
article into the aerosol-generating device with any rotational
orientation.
[0059] In any of the embodiments described above in which the
aerosol-generating article comprises an article data storage device
and one or more article data electrical contacts, the
aerosol-generating device preferably comprises one or more device
data electrical contacts for connecting to the one or more article
data electrical contacts.
[0060] At least one of the article data storage device and the
article data electrical contacts may be configured so that the
article data storage device can be accessed only in a read-only
mode. For example, the aerosol-generating device may comprise a
device data storage device storing one or more heating profiles,
wherein the article data storage device communicates the type of
aerosol-generating article to the aerosol-generating device via the
article data electrical contacts and the device data electrical
contacts so that the aerosol-generating device can select the
appropriate heating profile from the one or more heating profiles
stored within the device data storage device. Alternatively, the
article data storage device may communicate an appropriate heating
profile to the aerosol-generating device via the article data
electrical contacts and the device data electrical contacts.
[0061] Alternatively, at least one of the article data storage
device and the article data electrical contacts may be configured
so that the article data storage device can be accessed in a
read-write mode. For example, the aerosol-generating device may
read at least one of the type of aerosol-generating article and an
appropriate heating profile from the article data storage device,
as described above. Additionally, or alternatively, the
aerosol-generating device may write data to the article data
storage device. For example, the aerosol-generating device may
write data to the article data storage device to indicate that the
aerosol-generating article has been smoked. If the smoked
aerosol-generating article is then re-inserted into an
aerosol-generating device, the aerosol-generating device may read
the data from the article data storage device indicative of the
aerosol-generating article having been smoked and therefore prevent
the article being smoked again.
[0062] In those embodiments in which the aerosol-generating device
comprises a device data storage device, the device data storage
device may store one or more heating profiles, as described above.
Additionally, or alternatively, the device data storage device may
store usage data, such as the number of article smokes, the types
of articles smoked, the frequency of smoking, and such like.
[0063] The supply of electrical energy may be a DC voltage source.
In preferred embodiments, the supply of electrical energy is a
battery. For example, the supply of electrical energy may be a
nickel-metal hydride battery, a nickel cadmium battery, or a
lithium based battery, for example a lithium-cobalt, a
lithium-iron-phosphate or a lithium-polymer battery. The supply of
electrical energy may alternatively be another form of charge
storage device such as a capacitor. The supply of electrical energy
may require recharging and may have a capacity that allows for the
storage of enough energy for use of the aerosol-generating device
with one or more aerosol-generating articles.
[0064] In any of the embodiments described above, the tubular
housing preferably comprises one or more airflow inlets to allow
air to flow into the electrically heated aerosol-generating system
when a consumer draws on the aerosol-generating article during use.
Preferably, the one or more airflow inlets are positioned adjacent
the upstream end of the aerosol-generating article when the
aerosol-generating article is fully inserted into the
aerosol-generating device.
[0065] The aerosol-generating device may further comprise a sensor
to detect air flow indicative of a consumer taking a puff. The air
flow sensor may be an electro-mechanical device. Alternatively, the
air flow sensor may be any of: a mechanical device, an optical
device, an opto-mechanical device and a micro electro-mechanical
systems (MEMS) based sensor. Alternatively, the aerosol-generating
device may comprise a manually operable switch for a consumer to
initiate a puff.
[0066] Additionally, or alternatively, the aerosol-generating
device may further comprise a temperature sensor. The temperature
sensor may detect the temperature of the resistive heating element
or the temperature of the aerosol-generating article. The
temperature sensor may be a thermistor. Alternatively, the
temperature sensor may comprise a circuit configured to measure the
resistivity of the resistive heating element and derive a
temperature of the resistive heating element by comparing the
measured resistivity to a calibrated curve of resistivity against
temperature.
[0067] Preferably, the aerosol-generating device comprises an
indicator for indicating when the resistive heating element is
activated. The indicator may comprise a light, activated when the
heating element is activated. Additionally, or alternatively, the
aerosol-generating device may comprise an indicator for indicating
when the heater electrical contacts are in correct contact with the
device electrical contacts. In those embodiments in which the
aerosol-generating device comprises indicators for indicating when
the resistive heating element is activated and when the heater
electrical contacts are in correct contact with the device
electrical contacts the indicators may be different indicators or
they may be separate indicators. For example, the device may
comprise a single indicator comprising a light that activates only
when the heater electrical contacts are in correct contact with the
device electrical contacts and when the resistive heating element
is activated.
[0068] In any of the embodiments described above, the
aerosol-generating device may comprise an external plug or socket
allowing the aerosol-generating device to be connected to another
electrical device. For example, the aerosol-generating device may
comprise a USB plug or a USB socket to allow connection of the
aerosol-generating device to another USB enabled device. For
example, the USB plug or socket may allow connection of the
aerosol-generating device to a USB charging device to charge a
rechargeable supply of electrical energy within the
aerosol-generating device. In those embodiments in which the
aerosol-generating device comprises a device data storage device,
the USB plug or socket may additionally, or alternatively, support
the transfer of data to or from, or both to and from, the
aerosol-generating device. For example, the device may be connected
to a computer to download data from the device data storage device,
such as usage data. Additionally, or alternatively, the device may
be connected to a computer to transfer data to the device, such as
new heating profiles for new aerosol-generating articles, wherein
the heating profiles are stored within the device data storage
device.
[0069] In those embodiments in which the device comprises a USB
plug or socket, the device may further comprise a removable cover
that covers the USB plug or socket when not in use. In embodiments
in which the USB plug or socket is a USB plug, the USB plug may
additionally or alternatively be selectively retractable within the
device.
[0070] As described above, the resistive heating element may
comprise an electrically resistive heating track provided on an
elongate electrically insulating substrate. The present invention
extends to methods of manufacturing aerosol-generating articles
comprising such a resistive heating element, in accordance with any
of the embodiments described above. Therefore, according to a third
aspect of the present invention there is provided a method of
manufacturing an aerosol-generating article according to the first
aspect of the present invention in accordance with the embodiments
described above, the method comprising providing a tobacco plug and
a mouthpiece, and wrapping a wrapper around at least a portion of
the tobacco plug and the mouthpiece to secure the mouthpiece to a
downstream end of the tobacco plug. A resistive heating element is
provided, the resistive heating element comprising an electrically
resistive heating track on an elongate electrically insulating
substrate, and at least two heater electrical contacts for
receiving a supply of electrical energy and connected to the
electrically resistive heating track. At least a portion of the
elongate electrically insulating substrate is inserted into the
tobacco plug at an upstream end of the tobacco plug, wherein an
upstream portion of the resistive heating element protrudes from
the upstream end of the tobacco plug, and wherein the upstream
portion of the resistive heating element comprises the at least two
heater electrical contacts for receiving a supply of electrical
energy.
[0071] Providing an electrically resistive heating track on an
electrically insulating substrate simplifies the manufacture of the
aerosol-generating article by facilitating separate manufacture of
the resistive heating element, which is then inserted into the
tobacco plug after the remainder of the aerosol-generating article
has been constructed.
[0072] To facilitate the insertion of the resistive heating element
into the tobacco plug, the elongate electrically insulating
substrate is preferably shaped in the form of one of a rod, a
needle, a pin, a blade, or a cone, and wherein the step of
inserting at least a portion of the elongate electrically
insulating substrate into the tobacco plug comprises inserting the
rod, needle, pin, blade or cone into the tobacco rod.
[0073] Additionally, or alternatively, the elongate electrically
insulating substrate may comprise one or more serrated edges,
wherein the serrations are shaped to favour insertion of the
resistive heating element into the tobacco plug during the step of
inserting at least a portion of the elongate electrically
insulating substrate into the tobacco plug, and wherein the
serrations are shaped to resist removal of the resistive heating
element from the tobacco plug. Providing such serrated edges can
advantageously prevent the resistive heating element from becoming
dislodged from the tobacco plug when the aerosol-generating article
is removed from an aerosol-generating device.
[0074] In alternative embodiments, the elongate electrically
insulating substrate may have a helical shape so that the resistive
heating element can be screwed into and out of the tobacco plug but
cannot be pushed directly into or pulled directly out of the
tobacco plug. In such embodiments, the step of inserting at least a
portion of the elongate electrically insulating substrate into the
tobacco plug comprises screwing at least a portion of the elongate
electrically insulating substrate into the tobacco plug. Utilising
a helical shape can prevent the resistive heating element from
becoming dislodged from the tobacco plug when the
aerosol-generating article is removed from an aerosol-generating
device.
[0075] In those embodiments in which the resistive heating element
is disposable with the remainder of the aerosol-generating article,
the resistive heating element is preferably constructed from
low-cost materials, such as low cost metals and metal alloys.
Alternatively, in those embodiments in which the resistive heating
element is reusable, it may be cost-effective to manufacture the
resistive heating element from more expensive materials. For
example, reusable resistive heating elements may comprise an
elongate electrically insulating substrate formed from a
non-conductive ceramic.
[0076] Preferably, the electrically insulating substrate is
operable at a working temperature of up to about 700 degrees
Celsius, more preferably about 800 degrees Celsius. Additionally,
or alternatively, the operating temperature of the resistive
heating element during use may be about 250 degrees Celsius, more
preferably about 300 degrees Celsius.
[0077] Suitable materials for forming the electrically resistive
heating track include but are not limited to: semiconductors such
as doped ceramics, electrically "conductive" ceramics (such as, for
example, molybdenum disilicide), carbon, graphite, metals, metal
alloys and composite materials made of a ceramic material and a
metallic material. Such composite materials may comprise doped or
undoped ceramics. Examples of suitable doped ceramics include doped
silicon carbides. Examples of suitable metals include titanium,
zirconium, tantalum and metals from the platinum group. Examples of
suitable metal alloys include stainless steel, nickel-, cobalt-,
chromium-, aluminium- titanium- zirconium-, hafnium-, niobium-,
molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese- and
iron-containing alloys, and super-alloys based on nickel, iron,
cobalt, stainless steel, Timetal.RTM. and iron-manganese-aluminium
based alloys.
[0078] In some embodiments, the electrically resistive heating
track comprises one or more stamped portions of electrically
resistive material, such as stainless steel. Alternatively, the
electrically resistive heating track may comprise a heating wire or
filament, for example a Ni--Cr (Nickel-Chromium), platinum,
tungsten or alloy wire.
[0079] In any of the embodiments described above, the upstream
portion of the resistive heating element preferably comprises a
disc of electrically insulating material, wherein the disc
comprises an upstream face on which the at least two heater
electrical contacts are provided and a downstream face from which
the electrically insulating substrate extends. The step of
inserting at least a portion of the elongate electrically
insulating substrate into the tobacco plug comprises inserting the
elongate electrically insulating substrate until the downstream
face of the disc abuts the upstream end of the tobacco plug.
[0080] Providing the resistive heating element with a disc of
electrically insulating material at its upstream end advantageously
facilitates insertion of the resistive heating element into the
tobacco plug. Specifically, the elongate electrically insulating
substrate can be sized so that when the resistive heating element
is inserted into the tobacco plug so that the downstream face of
the disc of electrically insulating material abuts the upstream end
of the tobacco plug the elongate electrically insulating substrate,
and therefore the resistive heating track, are correctly positioned
within the tobacco plug.
[0081] Advantageously, the upstream face of the disc of
electrically insulating material also provides a large surface area
on which the at least two heater electrical contacts can be
provided, which facilitates the manufacture of the resistive
heating element.
[0082] The disc of electrically insulating material may be formed
from the same insulating material as the elongate electrically
insulating substrate, or they may be formed from different
materials. Preferably, the disc of electrically insulating material
and the elongate electrically insulating substrate are formed from
the same material. To simplify the manufacture of the resistive
heating element, the disc of electrically insulating material and
the elongate electrically insulating substrate are preferably
integrally formed from a single piece of electrically insulating
material. For example, the resistive heating element may formed by
moulding or otherwise casting an electrically insulating material
around the electrically resistive heating track.
[0083] In any of those embodiments in which the resistive heating
element comprises a disc of electrically insulating material, the
disc and the tobacco plug preferably both have a substantially
circular cross-sectional shape, wherein the diameter of the disc is
substantially the same as the diameter of the tobacco plug. This
advantageously facilitates correct insertion of the resistive
heating element into the tobacco plug. For example, a tubular guide
may be used during manufacture of the aerosol-generating article to
ensure that the disc of electrically insulating material is
positioned coaxially with the tobacco plug.
[0084] The present invention also extends to methods of
manufacturing tobacco plugs for use in manufacturing
aerosol-generating articles comprising a resistive heater element
within a tobacco plug, in accordance with any of the embodiments of
the first aspect of the present invention described above and
wherein the resistive heating element is incorporated into the
tobacco plug as the tobacco plug is formed. Therefore, according to
a fourth aspect of the present invention there is provided a method
of manufacturing a tobacco plug for use in an aerosol-generating
article according to the first aspect of the present invention, the
method comprising positioning a resistive heating element on a
forming belt, the resistive heating element comprising at least two
heater electrical contacts for receiving a supply of electrical
energy. A tobacco slurry is deposited onto the forming belt and
dried to form a dried tobacco sheet comprising the resistive
heating element. The dried tobacco sheet comprising the resistive
heating element is formed into a tobacco plug, the resistive
heating element positioned within the tobacco plug and comprising
an upstream portion protruding from an upstream end of the tobacco
plug, wherein the upstream portion of the resistive heating element
comprises the least two heater electrical contacts for receiving a
supply of electrical energy.
[0085] Forming the resistive heater element integrally with the
tobacco plug can simplify the manufacture of the aerosol-generating
article by reducing the number of assembly steps.
[0086] The resistive heating element may be positioned on the
forming belt and the tobacco slurry then deposited onto the forming
belt over the resistive heating element. Alternatively, the tobacco
slurry may be deposited on the forming belt and the resistive
heating element then positioned on the forming belt on top of the
tobacco slurry.
[0087] The step of forming the dried tobacco sheet into a tobacco
plug may comprise at least one of rolling and folding the dried
tobacco sheet.
[0088] To accommodate the step of forming the dried tobacco sheet
into a tobacco plug, the resistive heating element is preferably
flexible. For example, the resistive heating element may comprise a
flexible resistive wire.
[0089] The invention will now be further described, by way of
example only, with reference to the accompanying drawings in
which:
[0090] FIG. 1 shows an aerosol-generating article in accordance
with a first embodiment of the present invention;
[0091] FIG. 2 shows a detailed view of the heater electrical
contacts of the aerosol-generating article of FIG. 1;
[0092] FIG. 3 shows an alternative arrangement of heater electrical
contacts for use with the aerosol-generating article of FIG. 1;
[0093] FIG. 4 shows an aerosol-generative device for use with the
aerosol-generating article of FIG. 1;
[0094] FIG. 5 shows the aerosol-generating article of FIG. 1
inserted into the aerosol-generating device of FIG. 4 to form an
electrically heated aerosol-generating system;
[0095] FIG. 6 illustrates a method of forming the
aerosol-generating article of FIG. 1, in accordance with the
present invention; and
[0096] FIG. 7 shows an aerosol-generating article in accordance
with a second embodiment of the present invention and configured
for use with the aerosol-generating device of FIG. 4.
[0097] FIG. 1 shows an aerosol-generating article 10 in accordance
with a first embodiment of the present invention, the
aerosol-generating article 10 comprising a tobacco plug 12, a
hollow acetate tube 14, a polymeric filter 16, a mouthpiece 18 and
an outer wrapper 20.
[0098] The aerosol-generating article 10 further comprises a
resistive heating element 22 positioned within the tobacco plug 12,
the resistive heating element comprising a disc of electrically
insulating material 24 and an elongate electrically insulating
substrate 26 extending from a downstream face of the disc of
electrically insulating material 24. The disc of electrically
insulating material 24 and the elongate electrically insulating
substrate 26 are formed integrally as a single piece from a ceramic
material.
[0099] An electrically resistive heating track 28 is embedded
within the elongate electrically insulating substrate 26. Provided
on an upstream face of the disc of electrically insulating material
24 are heater electrical contacts 30, which are connected to the
electrically resistive heating track 28 for conducting a supply of
electrical energy from an aerosol-generating device to the
electrically resistive heating track 28.
[0100] FIG. 2 shows a detailed view of the heater electrical
contacts 30 on the upstream face of the disc of electrically
insulating material 24. The heater electrical contacts 30 comprise
a first heater electrical contact 32 having an annular shape and a
second heater electrical contact 34 having a circular shape and
positioned within the first heater electrical contact 32. The first
and second heater electrical contacts 32, 34 are centred on the
longitudinal axis of the disc of electrically insulating material
24 so that the orientation of the first and second heater
electrical contacts 32, 34 is not dependent upon the rotational
orientation of the aerosol-generating article 10 around its
longitudinal axis.
[0101] FIG. 3 shows an alternative arrangement of heater electrical
contacts for the aerosol-generating article 10 of FIG. 1. The
alternative arrangement of heater electrical contacts comprises a
first heater electrical contact 36 spaced apart from a second
heater electrical contact 38. Depending upon the configuration of
device electrical contacts in the aerosol-generating device with
which the aerosol-generating article 10 is used, it may be
necessary to insert the aerosol-generating article 10 into the
aerosol-generating device with a particular rotational orientation
when using the alternative heater electrical contact arrangement
show in FIG. 3. Therefore, in such embodiments the
aerosol-generating article 10 can be provided with an indexing
indicator to ensure correct rotational orientation of the
aerosol-generating article 10. For example, as shown in FIG. 3, a
groove 40 may be provided in the disc of electrically insulating
material 24, wherein the groove must be matched with a
correspondingly shaped ridge on an aerosol-generating device to
allow insertion of the aerosol-generating article 10 into the
aerosol-generating device.
[0102] FIG. 4 shows an aerosol-generating device 50 for use with
the aerosol-generating article of FIG. 1. The device 50 includes a
supply of electrical energy 52 in the form of a rechargeable
battery. A controller 54 controls the operation of the device 50,
including the supply of electrical energy from the battery to the
resistive heating element 22 of an aerosol-generating article 10.
The aerosol-generating device 50 comprises a tubular housing 55
housing the supply of electrical energy 52 and the controller 54,
the tubular housing 55 defining a cavity 57 for receiving the
aerosol-generating article 10. A plurality of airflow inlets 59 are
provided in the tubular housing 55 to allow air to flow into the
cavity 57 during use of the aerosol-generating device 50 with the
aerosol-generating article 10.
[0103] The aerosol-generating device 50 also comprises first and
second device electrical contacts 56, 58 that are arranged to
contact the heater electrical contacts 30 of the aerosol-generating
article 10 when the article is inserted into the cavity 57 to form
an electrically heated aerosol-generating system 60, as shown in
FIG. 5. During operation of the electrically heated
aerosol-generating system 60, electrical energy is supplied from
the battery to the resistive heating track 28 of the resistive
heating element 22 via the first and second device electrical
contacts 56, 58 and the first and second heater electrical contacts
32, 34.
[0104] FIG. 6 illustrates a method of forming the
aerosol-generating article 10 of FIG. 1 in which the tobacco plug
12, the hollow acetate tube 14, the polymeric filter 16, the
mouthpiece 18 and the outer wrapper 20 are pre-assembled. The
resistive heating element 22 is then inserted into the tobacco plug
12 until the downstream face of the disc of electrically insulating
material 24 abuts the upstream face of the tobacco plug 12, thus
forming the aerosol-generating article 10 of FIG. 1.
[0105] FIG. 7 illustrates an aerosol-generating article 100 in
accordance with a second embodiment of the present invention. The
aerosol-generating article 100 is substantially the same as the
aerosol-generating article 10 shown in FIG. 1, with the exception
of the resistive heating element, and like reference numerals are
used to designate like parts.
[0106] The aerosol-generating article 100 comprises a resistive
heating element 122 comprising an electrically resistive wire 126
positioned within the tobacco plug 12. The electrically resistive
wire 126 may be incorporated into the tobacco plug 12 during the
process of forming the tobacco plug 12. For example, the
electrically resistive wire 126 can be combined with a tobacco
slurry on a forming belt, after which the tobacco slurry is dried
to form a dried tobacco sheet comprising the electrically resistive
wire 126, the dried tobacco sheet then being formed into the
tobacco plug 12.
[0107] The resistive heating element 122 also comprises heater
electrical contacts 130 provided at the upstream end of the
aerosol-generating article 100 and connected to the electrically
resistive wire 126. The heater electrical contacts 130 can be
configured to permit use of the aerosol-generating article 100 with
the aerosol-generating device 50 of FIG. 4.
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