PCT
`WORLD INTELLECTUAL PROPERTY ORGANIZATION
`International Bureau
`INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION lREATY (PCI)
`(51) International Patent Clamification 6 :
`WO 95/27412
`A24F 47/00
`
`•
`
`(11) International Publication Number:
`
`Al
`
`(43) International Publication Date:
`
`19 October 1995 (19.10.95)
`
`(21) International Application Number:
`
`PCT/US95/04343
`
`(22) International Filing Date:
`
`6 April 1995 (06.04.95)
`
`(30) Priority Data:
`08/224,848
`08/370,125
`
`8 April 1994 (08.04.94)
`9 Januacy 1995 (09.01.95)
`
`us
`us
`
`(71) Applicant: PHILIP MORRIS PRODUCTS INC. [US/US];
`3601 Commerce Road, Richmond, VA 23234 (US).
`
`(72) Inventors: HAJALIGOL, Mohammad, R.; Aparunent H, 3322
`Old Courthouse Road, Richmond, VA 23236 (US). FLEIS(cid:173)
`CHHAUER, Grier, S.; 1004 Lady Jean Coun, Midlothian,
`VA 23313 (US). DEEVI, Seetharama, C.; 129 High Point
`Lane, Oak Ridge, TN 37830 (US). IDGGINS, Charles,
`T.; 30 Glenbrooke Circle, Richmond, VA 23229 (US).
`HA YES, Patrick, H.; 4540 Forresta1 Road, Chester, VA
`23831 (US). HERMAN, Herbert; 30 Waterview Drive,
`Pon Jefferson, NY 117n (US). GANSERT, Roben, V.;
`Apanment 2D, 20 Williams Boulevard, Lake Grove, NY
`11755 (US). COLLINS, Alfred, L; 2058 Hancock Road,
`Powhatan, VA 23139 (US). KEEN, Billy, J., Jr.; 12911
`Blue Staek Court, Chesterfield, VA 23832 (US). LAROY,
`Bernard, C.; 12821 Bailey Bridge Road, Richmond, VA
`23112 (US). LIT.LY, A., Clinton, Jr.; 9641 Waterfowl F1y(cid:173)
`way, Chesterfield, VA 23832 (US).
`
`(74) Agents: MAGNONE. Joseph, R. et al.; Bums, Doane, Swecker
`& Mathis, Washington and Prince Streets, P.O. Box 1404,
`Alexandria, VA 22313-1404 (US).
`
`(81) Designated States: AM, AT, AU, BB, BG, BR, BY, CA, CH,
`CN, CZ, DE. DK, EE, ES, FJ, GB, GE. HU, IS, JP, KE.
`KG, KP, KR, KZ, LK, LR, LT, LU, LV, MD, MG, MN,
`MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK,
`TJ, TM, TT, UA, UG, UZ, VN, European patent (AT, BE,
`CH, DE, DK, ES, FR, GB, GR, IE, IT, LU, MC, NL, PT,
`SE), OAPI patent (BF, BJ, CF, CG, CI, CM, GA, ON, ML,
`MR, NE, SN, TD, TG), ARIPO patent (KE, MW, SD, SZ,
`UG).
`
`Published
`With international search report.
`(54) Title: TUBULAR HEATER FOR USE IN AN ELECIRICAL SMOKING ARTICLE
`
`120'------..
`
`130
`
`300
`
`(57) Abstract
`
`..
`
`A cylindrical tube (300) is provided of a mechanically strong and flexible electrical conductor such as a metal and has a plurality of
`separated regions. An electrically insulating layer (310) such as a ceramic is applied on the outer surface except for one exposed portion
`(I 10). Electrically reslstive heaters (122) are then applied to the insulated regions and are electrically connected at one end to the underlying
`electrical conducting region. The electrical conductor is connected to the negative tenninal of a power source. The other end of all the
`heaters are adapted to be connected to the positive tenninal of the source. Accordingly, an electrically resistive heating circuit is fonned
`wherein the tube serves as a common for all of the heating elements. The tubular heater can comprise an exposed end hub with a plurality
`of blades extending therefrom. Each blade can have an individual heater deposited thereon. Alternatively, every other blade can have a
`heater deposited thereon. The blades having no heaters function as barriers to minimize outward escape of generated vapors. These bamer
`blades also function as heat sinks for the heaters on adjacent blades.
`
`Ex. 2023-0001
`
`

`

`FOR THE PURPOSES OF INFORMATION ONLY
`
`Codes used to identify States party to the PCT on the front pages of pamphlets publishing international
`applications under the PCT.
`
`AT
`AU
`BB
`BE
`BF
`BG
`BJ
`BR
`BY
`CA
`CF
`CG
`CH
`Cl
`CM
`CN
`cs
`CZ
`DE
`DK
`ES
`Fl
`FR
`GA
`
`Austria
`Australia
`Barbados
`Belgium
`Burkina Faso
`Bulgaria
`Benin
`Brazil
`Belarus
`Canada
`Central African Republic
`Congo
`Switzerland
`COie d'Ivoire
`Cameroon
`China
`Czechoslovakia
`Czech Republic
`Germany
`Denmark
`Spain
`Finland
`France
`Gabon
`
`GB
`GE
`GN
`GR
`HU
`IE
`IT
`JP
`KE
`KG
`KP
`
`KR
`KZ
`LI
`LK
`LU
`LV
`MC
`MD
`MG
`ML
`MN
`
`United Kingdom
`Georgia
`Guinea
`Greece
`Hungary
`Ireland
`Italy
`Japan
`Kenya
`Kyrgystan
`Democratic People's Republic
`of Korea
`Republic of Korea
`Kazakhstan
`Liechtenstein
`Sri Lanka
`Luxembourg
`Latvia
`Monaco
`Republic of Moldova
`Madagascar
`Mali
`Mongolia
`
`MR
`MW
`NE
`NL
`NO
`NZ
`PL
`PT
`RO
`RU
`SD
`SE
`SI
`SK
`SN
`TD
`TG
`TJ
`Tr
`UA
`us
`uz
`VN
`
`Mauritania
`Malawi
`Niger
`Netherlands
`Norway
`New Zealand
`Poland
`Portugal
`Romania
`Russian Federation
`Sudan
`Sweden
`Slovenia
`Slovakia
`Senegal
`Chad
`Togo
`Tajikistan
`Trinidad and Tobago
`Ukraine
`United States of America
`Uzbekistan
`Viet Nam
`
`Ex. 2023-0002
`
`

`

`WO95/27412
`
`PCT/US95/04343
`
`TUBULAR HEATER FOR
`USE IN AN ELECTRICAL SMOKING ARTICLE
`
`Technical Field of the Invention
`
`The present invention relates generally to heaters for use
`in an electrical smoking article and more particularly to a
`tubular heater for use in an electrical smoking article.
`
`Discussion of the Related Art
`
`Previously known conventional smoking devices deliver
`flavor and aroma to the user as a result of combustion of
`tobacco. A mass of combustible material, primarily tobacco,
`is oxidized as the result of applied heat with typical
`combustion temperatures in a conventional cigarette being
`in excess of 800° C during puffing. Heat is drawn through an
`adjacent mass of tobacco by drawing on the mouth end.
`During this heating, inefficient oxidation of the
`combustible material takes place and yields various
`distillation and pyrolysis products. As these products are
`drawn through the body of the smoking device toward the
`mouth of the user, they cool and condense to form an
`aerosol or vapor which gives the consumer the flavor and
`aroma associated with smoking.
`
`Conventional cigarettes have various perceived drawbacks
`associated with them. Among them is the production of
`sidestream smoke during smoldering between puffs, which may
`be objectionable to some non-smokers. Also, once lit, they
`must be fully consumed or be discarded. Relighting a
`conventional cigarette is possible but is usually an
`
`Ex. 2023-0003
`
`

`

`WO95/27412
`
`PCT/US95/04343
`
`unattractive prospect for subjective reasons (flavor,
`taste, odor) to a discerning smoker.
`
`Prior alternatives to the more conventional cigarettes
`include those in which the combustible material itself does
`not directly provide the flavorants to the aerosol inhaled
`by the smoker. In these smoking articles, a combustible
`heating element, typically carbonaceous in nature, is
`combusted to heat air as it is drawn over the heating
`element and through a zone which contains heatactivated
`elements that release a flavored aerosol. While this type
`of smoking device produces little or no sidestream smoke,
`it still generates products of combustion, and once lit it
`is not adapted to be snuffed for future use in the
`conventional sense.
`
`In both the more conventional and carbon element heated
`smoking devices described above combustion takes place
`during their use. This process naturally gives rise to many
`by-products as the combusted material breaks down and
`interacts with the surrounding atmosphere.
`
`Commonly assigned U.S. Patent Nos. 5,093,894; 5,225,498;
`5,060,671 and 5,095,921 disclose various electrical
`resistive heating elements and flavor generating articles
`which significantly reduce sidestream smoke while
`permitting the smoker to selectively suspend and reinitiate
`smoking. However, the cigarette articles disclosed in these
`patents are not very durable and may collapse, tear or
`break from extended or heavy handling. In certain
`circumstances, these prior cigarette articles may crush as
`they are inserted into the electric lighters. Once they are
`
`- 2 -
`
`Ex. 2023-0004
`
`

`

`WO 95/27412
`
`PCT/0S95/04343
`
`smoked, they are even weaker and may tear or break as they
`are removed from the lighter.
`
`International patent application WO 94/06314, describes an
`electrical smoking system including a novel electrically
`powered lighter and novel cigarette that is adapted to
`cooperate with the lighter. The preferred embodiment of the
`lighter includes a plurality of metallic sinusoidal heaters
`disposed in a configuration that slidingly receives a
`tobacco rod portion of the cigarette.
`
`The preferred embodiment of the cigarette of WO 94/06314
`preferably comprises a tobacco-laden tubular carrier,
`cigarette paper overwrapped about the tubular carrier, an
`arrangement of flow-through filter plugs at a mouthpiece
`end of the carrier and a filter plug at the opposite
`(distal) end of the carrier, which preferably limits air
`flow axially through the cigarette. The cigarette and the
`lighter are configured such that when the cigarette is
`inserted into the lighter, and as individual heaters are
`activated for each puff, localized charring occurs at spots
`about the cigarette in the locality where each heater was
`bearing against the cigarette. Once all the heaters have
`been activated, these charred spots are closely spaced from
`one another and encircle a central portion of the carrier
`portion of the cigarette. Depending on the maximum
`temperatures and total energies delivered at the heaters,
`the charred spots manifest more than mere discolorations of
`the cigarette paper. In most applications, the charring
`will create at least minute breaks in the cigarette paper
`and the underlying carrier material, which breaks tends to
`mechanically weaken the cigarette. For the cigarette to be
`withdrawn from the lighter, the charred spots must be at
`
`- 3
`
`-
`
`Ex. 2023-0005
`
`

`

`WO95/27412
`
`PCT/US95/04343
`
`least partially slid past the heaters. In aggravated
`circumstances, such as when the cigarette is wet or toyed
`with or twisted, the cigarette may be prone to break or
`leave pieces upon its withdrawal from the lighter. Pieces
`left in the lighter fixture can interfere with the proper
`operation of the lighter and/or deliver an off-taste to the
`smoke of the next cigarette. If the cigarette breaks in two
`while being withdrawn, the smoker may be faced not only
`with the frustration of failed cigarette product, but also
`with the prospect of clearing debris from a clogged lighter
`before he or she can enjoy another cigarette.
`
`The preferred embodiment of the cigarette of WO 94/06314 is
`essentially a hollow tube between the filter plugs at the
`mouthpiece end of the cigarette and the plug at the distal
`end. This construction is believed to elevate delivery to
`the smoker by providing sufficient space into which aerosol
`. can evolve off the carrier with minimal impingement and
`condensation of the aerosol on any nearby surfaces.
`
`Several proposals have been advanced which significantly
`reduce undesired sidestream smoke while permitting the
`smoker to suspend smoking of the article for a desired
`period and then to resume smoking. For example, commonly
`assigned U.S. Patent Nos. 5,093,894; 5,225,498; 5,060,671
`and 5,095,921 disclose various heating elements and flavor
`generating articles. WO 94/06314 discloses an electrical
`smoking article having heaters which are actuated upon
`sensing of a draw by control and logic circuitry. The
`heaters are preferably a relatively thin serpentine
`structure to transfer adequate amounts of heat to the
`cigarette and is lightweight.
`
`- 4 -
`
`Ex. 2023-0006
`
`

`

`WO95/27412
`
`PCT/US95/04343
`
`Although these devices and heaters overcome the observed
`problems and achieve the stated objectives, many
`embodiments are plagued by the formation of a significant
`amount of condensation formed as the tobacco flavor medium
`is heated to form vapors. These vapors can cause problems
`as they condense on relatively cooler various electrical
`contacts and the associated control and logic circuitry. In
`addition, condensation can influence the subjective flavor
`of the tobacco medium of the cigarette. Though
`not desiring to be bound by theory, it is believed that the
`condensation is the result of the flow pattern and pressure
`gradient of ambient air drawn through the article and the
`current designs of the heater assemblies. The heating of
`the tobacco flavor medium releases vapors which are then
`cooled to result in condensation on the surfaces of
`relatively cooler components. The condensation can cause
`shorting and other undesired malfunctions.
`
`In addition, the proposed heaters are subject to mechanical
`weakening and possible failure due to stresses induced by
`inserting and removing the cylindrical tobacco medium and
`also by adjusting or toying with the inserted cigarette.
`
`Also, the electrical smoking articles employ electrically
`resistive heaters which have necessitated relatively
`complex electrical connections which can be disturbed by
`insertion and removal of the cigarette.
`
`According to the invention there is provided a heater for
`use in a smoking article having a source of electrical
`energy for heating tobacco flavor medium, the heater
`comprising:
`a substrate of electrically conducting material;
`
`-
`
`5
`
`-
`
`Ex. 2023-0007
`
`

`

`WO95/27412
`
`PCT/US95/04343
`
`an electrical insulator deposited on at least a
`portion of said substrate; and
`an electrically resistive heater element deposited on
`said electrical insulator, a first end of said heater
`element electrically connected to said electrically
`conducting substrate, wherein a second end of said heater
`element and a portion of said heater element between the
`first and second ends of said heater element are
`electrically insulated from said electrically conducting
`substrate by said insulator,
`wherein said substrate and said second end of said
`heater element are adapted to be electrically connected to
`the source of electrical energy, wherein a resistive
`heating circuit is formed to heat said heating element,
`which in turn heats the tobacco flavor medium.
`
`The invention also provides a heater for use in a smoking
`article having a source of electrical energy for heating a
`cylindrical cigarette, the heater comprising:
`a cylindrical tube, of an electrically conducting
`material, and provided with a plurality gaps therethrough
`to define (a) a plurality of electrically conducting blades
`defining a receptacle to receive an inserted cylindrical
`cigarette and (b) an electrically conducting, common end
`hub supported within the smoking article, the blades
`extending from the end hub;
`an electrical insulator deposited on at least one of
`the plurality of electrically conducting blades;
`an electrically resistive heater element deposited on
`said insulator, a first end of said heater element being
`electrically connected to the at least one of the plurality
`of electrically conducting blades, and the second end of
`said heater element and a portion of said heater element
`
`- 6 -
`
`Ex. 2023-0008
`
`

`

`WO 95/27412
`
`PCT/US95/04343
`
`between the first and second ends are electrically
`insulated from said at least one electrically conducting
`blade by said insulator;
`wherein said end hub is adapted to be in electrical
`contact with the source of electrical energy, and the
`second end of said heater element is adapted to be in
`electrical contact with the source of electrical energy,
`wherein a resistive heating circuit is formed to heat said
`electrically resistive heater element, which in turn heats
`the inserted cigarette.
`
`The invention further provides method of forming a heater
`for use in an electrical smoking article for heating a
`cylindrical cigarette, the method comprising the steps of:
`providing an electrically conducting material;
`forming (a) a plurality of blades from the electrically
`conducting material having gaps therebetween, and (b) a
`common end section, the blades extending from the common
`end section;
`forming an electrical insulator on at least one of the
`plurality of electrically conducting blades;
`forming an electrically resistive heater on the formed
`electrical insulator such that a first end of the heater is
`in electrical contact with the at least one electrically
`conducting blade;
`forming an electrical contact on a second end of the
`formed heater; and
`forming the plurality of blades and the common section
`into a cylindrical receptacle to receive an inserted
`cigarette.
`
`- 7 -
`
`Ex. 2023-0009
`
`

`

`WO95/27412
`
`PCT/US95/04343
`
`A heater embodying the invention has the advantage of
`generating from a tobacco medium without sustained
`combustion.
`
`Embodiments of the invention may have the advantag that
`they reduce the creation of undesired sidestream smoke, and
`the further advantage of permitting the smoker to suspend
`and resume use.
`
`Furthermore, the above mentioned advantages may be obtained
`while reducing aerosol or smoke condensation within the
`smoking article.
`
`A preferred embodiment of the invention may have the
`advantage of providing a desired number of puffs and which
`to change the number and
`may be modified straightforwardly
`or duration of puffs provided without sacrificing
`subjective qualities of the tobacco.
`
`Embodiments of the invention may have the advantage of
`providing a heating element for a smoking article which is
`mechanically suitable for insertion and removal of a
`cigarette; which simplify connections of an electrically
`and which
`resistive heater to an associated power source;
`provide a heater which is more economical to manufacture.
`Preferably these advantages are achieved in a simple and
`straightforward manner.
`
`In a preferred embodiment of the invention, a cylindrical
`tube is provided of a mechanically strong and flexible
`electrical conductor such as a metal and has a plurality of
`separated regions. An electrically insulating layer such as
`a ceramic is applied on the outer surface except for one
`
`- 8 -
`
`Ex. 2023-0010
`
`

`

`WO95/27412
`
`PCT/US95/04343
`
`exposed portion. Electrically resistive materials are then
`applied to the insulated regions and are electrically
`connected at one end to the underlying electrical
`conducting region to form heater elements. This electrical
`conducting region is connected to the negative terminal of
`a power source. The other end of all the heaters are
`adapted to be connected to the positive terminal of the
`source. Accordingly, an electrically resistive heating
`circuit is formed wherein the tube serves as a common for
`all of the heating elements.
`
`The tubular heater can comprise an exposed end hub with a
`plurality of blades extending therefrom. Each blade can
`have an individual heater deposited thereon. Alternatively,
`every other blade can have a heater deposited thereon. The
`blades having no heater function as barriers to minimize
`outward escape of generated vapors. These barrier blades
`also function as heat sinks for the heaters on adjacent
`blades.
`
`Embodiments of the invention will now be described, by way
`of example, and with reference to the accompanying
`drawings, in which:
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a partially exposed perspective view of a smoking
`article employing a heater embodying the present invention;
`FIG. 2 is a side, cross-sectional view of a cigarette used
`in conjunction with an embodiment of the present invention;
`FIG. 3 is a side, cross-sectional view of a heater fixture
`embodying the present invention;
`
`- 9 -
`
`Ex. 2023-0011
`
`

`

`WO95/27412
`
`PCTffiS95/04343
`
`FIG. 4 is an exposed side view of a tubular heater
`embodying the present invention;
`FIG. 5 is an exposed side view of a heater blade having a
`metal substrate;
`FIG. 6A is a perspective view of dual hubs having a
`plurality of alternating barrier and heater blades
`extending therebetween;
`FIG. 6B is an embodiment similar to that of FIG. 6A except
`that the gaps between blades are shaped as an elongated U;
`FIG. 7 is a perspective view of the embodiment depicted in
`FIG. 6A having heater elements deposited on every defined
`blade;
`FIG. 8 is a perspective view of a heater having a single
`supporting hub;
`FIG. 9 is a perspective view of tubular heater having
`spiralled gaps;
`FIG. 10 is an exposed side view of a tubular heater having
`heater elements on inner faces of heater blades;
`FIG. 11 is a perspective view of an arrangement of heater
`blades prior to rolling;
`FIG. 12 is a perspective of view of a tubular heater having
`a common blade;
`FIG. 13 is a top view of an arrangement of heater blades
`prior to folding; and
`FIG. 14 is a perspective view of another arrangement of a
`tubular heater.
`
`DETAILED DESCRIPTION OF BEST MODE
`
`A smoking system 21 embodying the present invention is
`generally seen with reference to FIGS. 1 and 2. The smoking
`system 21 includes a cylindrical aerosol generating tube or
`
`- 10 -
`
`Ex. 2023-0012
`
`

`

`WO95/27412
`
`PCT/US95/04343
`
`cigarette 23 and a reusable lighter 25. The cigarette 23 is
`adapted to be inserted in and removed from an orifice 27 at
`a front end 29 of the lighter 25. The smoking system 21 is
`used in much the same fashion as a conventional cigarette.
`The cigarette 23 is disposed of after one or more puff
`cycles. The lighter 25 is preferably disposed of after a
`greater number of puff cycles than the cigarette 23.
`
`The lighter 25 includes a housing 31 and has front and rear
`portions 33 and 35. A power source 37 for supplying energy
`to heating elements for heating the cigarette 23 is
`preferably disposed in the rear portion 35 of the lighter
`25. The rear portion 35 is preferably adapted to be easily
`opened and closed, such as with screws or with snap-fit
`components, to facilitate replacement of the power source
`37. The front portion 33 preferably houses heating elements
`and circuitry in electrical communication with the power
`source 37 in the rear portion 35. The front portion 33 is
`preferably easily joined to the rear portion 35, such as
`with a dovetail joint or by a socket fit. The housing 31 is
`preferably made from a hard, heat-resistant material.
`Preferred materials include metal-based or, more
`preferably, polymer-based materials.
`The housing 31 is
`preferably adapted to fit comfortably in the hand of a
`smoker and, in a presently preferred embodiment, has
`overall dimensions of 10.7 cm by 3.8 cm by 1.5 cm.
`
`The power source 37 is sized to provide sufficient power
`for heating elements that heat the cigarette 23. The power
`source 37 is preferably replaceable and rechargeable and
`may include devices such as a capacitor, or more
`preferably, a battery. In a presently preferred embodiment,
`the power source is a replaceable, rechargeable battery
`
`- 11 -
`
`Ex. 2023-0013
`
`

`

`WO95/27412
`
`PCT/US95/04343
`
`such as four nickel cadmium battery cells connected in
`series with a total, non-loaded voltage of approximately
`4.8 to 5.6 volts. The characteristics required of the power
`source 37 are, however, selected in view of the
`characteristics of other components in the smoking system
`21, particularly the characteristics of the heating
`elements. U.S. Patent No. 5,144,962 describes several forms
`of power sources useful in connection with the smoking
`system of the present invention, such as rechargeable
`battery sources and quick-discharging capacitor power
`sources that are charged by batteries, and is hereby
`incorporated by reference.
`
`A substantially cylindrical heating fixture 39 for heating
`the cigarette 23, and, preferably, for holding the
`cigarette in place relative to the lighter 25, and
`electrical control circuitry 41 for delivering a
`predetermined amount of energy from the power source 37 to
`heating elements (not seen in FIGS. 1 and 2) of the heating
`fixture are preferably disposed in the front 33 of the
`lighter. As described in greater detail below, a generally
`circular, terminal end hub 110 is fixed, e.g., welded, to
`be disposed within the interior of heater fixture 39, e.g.,
`is fixed to spacer 49, as shown in FIG. 3. If the heater
`has two end hubs, either hub can serve as the fixed
`terminal end. In the presently preferred embodiment, the
`heating fixture 39 includes a plurality of radially spaced
`heating elements 122 supported to extend from the hub, seen
`in FIG. 3 and described in greater detail below, that are
`individually energized by the power source 37 under the
`control of the circuitry 41 to heat a number of, e.g.,
`eight, areas around the periphery of the inserted cigarette
`23. Eight heating elements 122 are preferred to develop
`
`- 12 -
`
`Ex. 2023-0014
`
`

`

`WO95/27412
`
`PCT/US95/04343
`
`eight puffs as in a conventional cigarette and eight heater
`elements also lend themselves to electrical control with
`binary devices. A desired number of puffs can be generated,
`e.g., any number between 5-16, and preferably 6-10 or 8 per
`inserted cigarette. As discussed below, the number of
`heaters can exceed the desired number of puffs/cigarette.
`
`The circuitry 41 is preferably activated by a puff-actuated
`sensor 45, seen in FIG. 1, that is sensitive either to
`pressure drops that occur when a smoker draws on the
`cigarette 23. The puff-actuated sensor 45 is preferably
`disposed in the front 33 of the lighter 25 and communicates
`with a space inside the heater fixture 39 and near the
`cigarette 23 through a passageway extending through a
`spacer and a base of the heater fixture and, if desired, a
`puff sensor tube (not shown). A puff-actuated sensor 45
`suitable for use in the smoking system 21 is described in
`U.S. Patent No. 5,060,671, the disclosure of which is
`incorporated by reference, and is in the form of a Model
`163PC01D35 silicon sensor, manufactured by the MicroSwitch
`di vision of Honeywell, Inc., Freeport, ,Illinois, which
`activates an appropriate one of the heater elements 122 as
`a result of a change in pressure when a smoker draws on the
`cigarette 23. Flow sensing devices, such as those using
`hot-wire anemometry principles, have also been successfully
`demonstrated to be useful for activating an appropriate one
`of the heater elements 122 upon detection of a change in
`air flow.
`
`An indicator 51 is preferably provided on the exterior of
`the lighter 25, preferably on the front 33, to indicate the
`number of puffs remaining on a cigarette 23 inserted in the
`lighter. The indicator 51 preferably includes a seven-
`
`- 13 -
`
`Ex. 2023-0015
`
`

`

`WO 95/27412
`
`PCT/US95/04343
`
`segment liquid crystal display. In a presently preferred
`embodiment, the indicator 51 displays the digit 11 8 11 for use
`with an eight-puff cigarette when a light beam emitted by a
`light sensor 53, seen in FIG. 1, is reflected off of the
`front of a newly inserted cigarette 23 and detected by the
`light sensor. The light sensor 53 is preferably mounted in
`an opening in the spacer and the base of the. heater
`fixture 39. The light sensor 53 provides a signal to the
`circuitry 41 which, in turn, provides a signal to the
`indicator 51. For example, the display of the digit 11 8 11 on
`the indicator 51 reflects that the preferred eight puffs
`provided on each cigarette 23 are available, i.e., none of
`the heater elements 43 have been activated to heat the new
`cigarette. After the cigarette 23 is fully smoked, the
`indicator displays the digit "0". When the cigarette 23 is
`removed from the lighter 25, the light sensor 53 does not
`detect the presence of a cigarette 23 and the indicator 51
`is turned off. The light sensor 53 is modulated so that it
`does not constantly emit a light beam and provide an
`unnecessary drain on the power source 37. A presently
`preferred light sensor 53 suitable for use with the smoking
`system 21 is a Type OPR5005 Light Sensor, manufactured by
`OPTEX Technology, Inc., 1215 West Crosby Road, Carroliton,
`Texas 75006 U.S.A.
`
`As one of several possible alternatives to using the above(cid:173)
`noted light sensor 53, a mechanical switch (not shown) may
`be provided to detect the presence or absence of a
`cigarette 23 and a reset button (not shown) may be provided
`for resetting the circuitry 41 when a new cigarette is
`inserted in the fighter 25, e.g., to cause the indicator 51
`to display the digit 11 8 11
`, etc. Power sources, circuitry,
`puff-actuated sensors, and indicators useful with the
`
`- 14 -
`
`Ex. 2023-0016
`
`

`

`WO95/27412
`
`PCT/US95/04343
`
`smoking system 21 of the present invention are described in
`U.S. Patent No. 5,060,671 and WO 94/06314, both of which
`are incorporated by reference. The passageway and the
`opening 50 in the spacer and the heater fixture base are
`preferably air-tight during smoking.
`
`A presently preferred cigarette 23 for use with the smoking
`system 21 will now be described and is shown in greater
`detail in the above-mentionad WO 94/06314, although the
`cigarette may be in any desired form capable of generating
`a flavored tobacco response for delivery to a smoker when
`the cigarette is heated by the heating elements 122.
`Referring to FIG. 2, the cigarette 23 includes a tobacco
`web 57 formed of a carrier or plenum 59 which supports
`tobacco flavor material 61, preferably including tobacco.
`The tobacco web 57 is wrapped around and supported by a
`cylindrical back-flow filter 63 at one end and a
`cylindrical first free-flow filter 65 at an opposite end.
`The first free-flow filter 65 is preferably an 'open-tube'
`type filter having a longitudinal passage 67 extending
`through the center of the first free-flow filter and,
`hence, provides a low resistance to draw or free flow.
`
`If desired, cigarette overwrap paper 69 is wrapped around
`the tobacco web 57. Types of paper useful as the overwrap
`paper 69 include a low basis weight paper, preferably a
`paper with a tobacco flavor coating, or a tobacco-based
`paper to enhance the tobacco flavor of a flavored tobacco
`response. A concentrated extract liquor in full or diluted
`strength may be coated on the overwrap paper 69. The
`overwrap paper 69 preferably possesses a minimal base
`weight and caliper while providing sufficient tensile
`strength for machine processes. Presently preferred
`
`- 15 -
`
`Ex. 2023-0017
`
`

`

`WO95/27412
`
`PCT/US95/04343
`
`characteristics of a tobacco-based paper include a basis
`weight (at 60% relative humidity) of between 20-25 grams/m2
`,
`minimum permeability of 0-25 CORESTA (defined as the amount
`of air, measured in cubic centimeters, that passes through
`one square centimeter of material, e.g., a paper sheet, in
`one minute at a pressure drop of 1.0 kilopascal), tensile
`strength~ 2000 grams/27 mm width (1 in/min), caliper 1.3 -
`1.5 mils, CaCO3 contents 5%, citrate 0%. Materials for
`forming the overwrap paper 69 preferably include~ 75%
`tobacco-based sheet (non-cigar, flue- or flue-lair-cured
`mix filler and bright stem). Flax fiber in amounts no
`greater than that necessary to obtain adequate tensile
`strength may be added. The overwrap paper 69 can also be
`conventional flax fiber paper of basis weight 15-20 g/m2 or
`such paper with an extract coating. Binder in the form of
`citrus pectin may be added in amounts less than or equal to
`1%. Glycerin in amounts no greater than necessary to obtain
`paper stiffness similar to that of conventional cigarette
`paper may be added.
`
`The cigarette 23 also preferably includes a cyiindrical
`mouthpiece filter 71, which is preferably a conventional
`RTD-type (Resistance To Draw) filter, and a cylindrical
`second free-flow filter 73. The mouthpiece filter and the
`second free-flow filter are secured to one another by
`tipping paper 75. The tipping paper 75 extends past an end
`of the second free-flow filter 73 and is attached to the
`overwrap paper 69 to secure an end of the first free-flow
`filter 65 in position adjacent an end of the second free(cid:173)
`flow filter 73. Like the first free-flow filter 65, the
`second free-flow filter 73 is preferably formed with a
`longitudinal passage 77 extending through its center. The
`back-flow filter 63 and the first free-flow filter 65
`
`- 16 -
`
`Ex. 2023-0018
`
`

`

`WO 95/27412
`
`PCT/US95/04343
`
`define, with the tobacco web 57, a cavity 79 within the
`cigarette 23.
`
`It is preferred that the inside diameter of the
`longitudinal passage 77 of the second free-flow filter 73
`be larger than the inside diameter of the longitudinal
`passage 67 of the first free-flow filter 65. Presently
`preferred inside diameters for the longitudinal passage 67
`are between 1-4 mm and for the longitudinal passage 77 are
`between 2-6 mm. It has been observed that the different
`inside diameters of the passages 67 and 77 facilitates
`development of a desirable mixing or turbulence between the
`aerosol developed from the heated tobacco flavor material
`and air drawn in from outside the cigarette 23 during
`drawing on the cigarette, resulting in an improved flavored
`tobacco response and facilitating exposure of more