PCT
`WORLD INTELLECTUAL PROPERTY ORGANIZATION
`ln1cm111ional Bureau
`INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCl)
`WO 94/ 06314
`(11) International Publication Number:
`(SJ) Intematlon1l Patent Oassification S :
`A24F47/00
`
`Al
`
`(43) International Publication Date:
`
`31 March 1994 (31.03.94)
`
`PCT/US93/08457
`(21) Internationa l Application Number:
`10 September 1993 (10.09.93)
`(22) lnttrnatfonal Fi ling Date:
`(30) Priorily data:
`11 September 1992 (I 1.09.92) US
`943,504
`(71) Applicant: PHILIP MORRIS PRODUCTS INC. [US/
`US]; 3601 Commen:ie Road, Richmond, VA 23234 (US).
`(72) tn,·entors: COLLINS, Alfred, L. ; 2058 Hancock Road, Po(cid:173)
`whatan, VA 23139 (US). COUNTS, Mary, Ellen ; 4506
`Cutshaw Avenue, Richmond, VA 231 12 (US). DAS, Am(cid:173)
`itabh ; 7201 Decidedly Lane, Midlothian, VA 23112
`(US). DEEVI, Scetharama, C. ; 8519 Whirlaway Drive,
`Midlothian, VA 23112 (US). FLEISC HHAUER, Grier,
`S. ; 1004 Lady Jean Court, Midlothian, VA 23113 (US).
`HAJALOGOL, Mohammad, R. ; 4509 Adelaide Ave(cid:173)
`nue, Richmond, VA 23234 (US). HA YES, Patrick, H. ;
`4540 Forrestal Road, Chester, VA 23831 (US). HIG(cid:173)
`GINS, Charles, T. ; 30 Olenbrooke Circle, Richmond,
`VA 23339 (US). HOUCK, Willie, G., Jr. ; 7753 Lake For(cid:173)
`est Drive, Richmond, VA 23835 (US). KEEN, Billy, J.,
`Jr. ; 12911 Blue Stack Court, Chesterfield, VA 23832
`(US). LAROY, Bernard, C. ; 12821 Bailey Bridge Road,
`Richmond, VA 231 12 (US). LEE, Robert, E., III ; 11802
`Prince Regent Place, Richmond, VA 23233 (US). LILLY,
`A., Clifton, Jr. ; 9641 Waterfowl Ayway, Chesterfield,
`VA 23832 (US). LIPOWJCZ, Peter, J.; 4300 North Heri(cid:173)
`tage Woods Road, Midlothian, VA 23112 (US). LOSEE,
`D., Bruce, Jr. ; 3912 Parle Avenue, Richmond, VA 23221
`(US). McCAFFERTY, Hugh, J. ; 2811 Bosham Lane,
`Midlothian, VA 23113 (US). MISER, Donald, E. ; 6912
`Velvet Antler Drive, Midlothian, VA 23112 (US).
`
`NICHOLS, Constance, H. ; 9608 Summercliff Court,
`Chesterfield , VA 23832 (US). RAYMOND, Wynn, R. ;
`6401 Wilton Rood, Richmond, VA 23832 (US). RI(cid:173)
`PLEY, Robert, L. ; 8140 Ammonette Drive, Richmond,
`VA 23235 (US). RITT, Renzer, R., Sr. ; 1517 Chevelle
`Drive, Richmond, VA 23235 (US). SCOTT, G., Robert ;
`13381 Drakewood Road, Midlothian, VA 23113 (US).
`SPRINKEL, F., Murphy : Route 4, Box 347, Glen All(cid:173)
`en, VA 23060 (US). STEVENS, William, H. ; 1959 Albi(cid:173)
`on Road, Midlothian, VA 23113 (US). SUBBIAH, Man(cid:173)
`thorom ; 2430 Olde Queen Terrace, Midlothian, VA
`23113 (US). UTSCH, Francis, V.; 13000 Robious Road,
`Midlothia.n, VA 23113 (US). WATKINS, Michael, L. ;
`3318 Grove Avenue, Chester, VA 23831 (US). WRENN,
`Susan, E. ; 12130 Ivy Mill Road, Chesterfield, Virginia
`23832 (US).
`(74) Agents: MAGNONE, Joseph, R. et al.; Bums, Doane,
`Swecker & Mathis, George Mason Building, Washing(cid:173)
`ton and Prince Streets, P.O. Box 1404, Alexandria, VA
`22313-1404 (US).
`(81) Des ignated States: AU, BG, BR, BY, CA, CZ, Fl, H U, JP,
`KP, KR, KZ, LY, NO, NZ, PL, RO, RU, SK, UA, UZ,
`VN, European patent (BE, FR, G R, IE, IT, MC), OAP!
`patent ( BF, BJ, CF, CG, Cl, CM, GA, GN, ML, MR,
`NE, SN, TD, TG).
`Published
`With intunarional search report.
`Before the expiration of the rime limit for amending the
`daims and ro be republished in the event of the receipt of
`amendmenu.
`
`(S4)Title: ELECTRICAL SMOKING SYSTEM FOR DELIVERING FLAVORS AND METHOD FOR MAKING SAME
`
`31
`
`21 "
`
`t
`
`(57) Abstract
`A smoking system (21) is provided in which a replaceable cigarette (23) containing tobacco n avor material is electrically
`heated by a set of electrical heater elements contained within a lighter (25) to evolve tobacco navors or other components in vapor
`or aerosol fonn for delivery to a smoker. The cigarette (23) and lighter (25) are adapted to provide air now patterns through the
`smoking system such that air nows transversely into the cigarette (23). Such patterns improve aerosol and navor delivery to the
`s moker and reduce the condensation of residual heater-region vapor/ aerosol in the smoking system.
`
`Ex. 2022-0001
`
`

`

`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
`BC
`BJ
`BR
`BV
`CA
`CF
`cc
`CH
`Cl
`CM
`CN
`cs
`CZ
`DE
`DK
`ES
`Fl
`
`Austria
`Australia
`Barbados
`Belgium
`Burkina Faso
`Bulgaria
`Benin
`Br~il
`Belarus
`canada
`Central African Republic
`Congo
`Switzerland
`Cote d'Ivoire
`cameroon
`China
`Czechoslovakia
`Czech Republic
`Germany
`Denmark
`Spain
`Finland
`
`FR
`GA
`GB
`GN
`GR
`HU
`IE
`IT
`JP
`KP
`
`KR
`KZ
`LI
`LK
`LU
`LV
`MC
`MG
`ML
`MN
`
`France
`Gabon
`United Kingdom
`Guinea
`Greece
`Hungary
`Ireland
`llaly
`Japan
`Democratic People's Republic
`or Korea
`Republic of Korea
`Kazakhstan
`Liechtenstein
`Sri Lanka
`Luxembourg
`Latvia
`Monaco
`Madagascar
`Mali
`Mongolia
`
`MR
`MW
`NE
`NL
`NO
`NZ
`PL
`PT
`RO
`RU
`SD
`SE
`SI
`SK
`SN
`TD
`TG
`UA
`us
`uz
`VN
`
`Mauritania
`Malawi
`Niger
`Netherlands
`Norway
`New Zealand
`Poland
`Porlugal
`Romania
`Russian Federalion
`Sudan
`Sweden
`Slovenia
`Slovak Republic
`Senegal
`Chad
`Togo
`Ukraine
`United States of America
`Uzbekislan
`Viet Nam
`
`Ex. 2022-0002
`
`

`

`WO94/06314
`
`PCT/US93/08457
`
`ELECTRICAL SMOKING SYSTEM FOR DELIVERING
`FLAVORS AND METHOD FOR MAKING SAME
`
`cross-Reference to Related Applications
`This application is a continuation-in-part of
`copending, commonly-assigned United States Patent
`Application Serial No. 07/666,926, filed March 11, 19,91, now
`5 abandoned in favor of file-wrapper continuation application
`Serial No. 08/012,799, filed. February 2, 1993, which is
`hereby incorporated in its entirety.
`
`Background of the Invention
`This invention relates to smoking systems in which
`10 cigarettes are used with lighters, and methods for making
`the same.
`
`20
`
`An electrical smoking article is described in
`commonly-assigned United States Patent No. 5,060,671, which
`is hereby incorporated by reference in its entirety. That
`15 patent describes a smoking article which is provided with a
`disposable set of electrical heating elements. A charge of
`tobacco flavor medium containing, for example, tobacco or
`tobacco-derived material is deposited on each of the heating
`elements. The disposable heater/flavor unit is mated to a
`source of electrical energy such as a battery or capacitor,
`as well as to control circuitry to actuate the heating ele(cid:173)
`ments in response to a puff by a smoker on the article or in
`response to the depression of a manual switch. The
`circuitry is designed so that at least one, but less than
`25 all of the heating elements are actuated for any one puff,
`and so that a predetermined number of puffs, each containing
`a pre-measured amount of tobacco flavor substance, e.g., an
`aerosol containing tobacco flavors or a flavored tobacco
`response, is delivered to the smoker. The circuitry also
`30 preferably prevents the actuation of any particular heater
`more than once, to prevent overheating of the tobacco flavor
`medium thereon.
`
`Ex. 2022-0003
`
`

`

`WO 94/06314
`
`PCT/US93/08457
`
`-
`
`2 -
`
`5
`
`10
`
`With such articles, the heater is thrown away with
`the spent remainder of tobacco material. Also, the
`electrical connections between the heaters and the battery
`must be able to endure repeated release and reconnection as
`flavor units are replaced.
`Incopending, commonly-assigned United States
`Patent Application Serial No. 07/666,926, filed March 11,
`1991, now abandoned in favor of Continuing Application
`Serial No. 08/012,799, filed February 2, 1993, an electrical
`smoking article is disclosed that has reusable heating ele(cid:173)
`ments and a disposable portion for tobacco flavor gener(cid:173)
`ation. The disposable portion preferably includes a flavor
`segment and a filter segment, attached by a tipping paper or
`other fastening arrangement. Certain operational
`15 difficulties are, however, associated with reusable heating
`elements, particularly in that residual aerosol tends to
`settle and condense on the heating elements and other
`permanent structural components of the article.
`In light of the above, it is therefore desirable
`to be able to provide an improved smoking system in which
`the heating elements of the lighter are reusable.
`It is also desirable to be able to provide such a
`system in which condensation of aerosol onto the heating
`elements and other structural components of the lighter is
`25 minimized.
`It is further desirable to provide a smoking
`article which is easier to manufacture.
`It is still further desirable to provide a smoking
`article which provides improved flavor delivery to the
`smoker.
`
`20
`
`30
`
`Summary of the Invention
`Accordingly, a primary object of the present
`invention is to provide a novel smoking system which
`provides advantages over prior systems.
`
`Ex. 2022-0004
`
`

`

`WO94/06314
`
`PCT/US93/084S7
`
`-
`
`3 -
`
`Another object of the present invention is to
`provide improved flavor delivery from a smoking system in
`which cigarettes are used with lighters.
`It is also an object of this invention to provide
`5 a smoking system in which the heating elements of a lighter
`are reusable, and of which the volume c;f disposable portions
`is minimized.
`It is also an object of this invention to provide
`a system in which condensation of aerosol onto heating
`10 elements and other structural components of a lighter is
`minimized.
`It is a further object of this invention to
`provide a smoking article and manufacturing processes for
`making the same that are easier and cost effective, even at
`15 state-of-tho-art mass production speeds.
`It is a still further object of this invention to
`provide improved aerosol and flavor delivery to the smoker.
`In accordance with one aspect of the present
`invention, a cigarette for use in a smoking system for
`20 delivering a flavored tobacco response to a smoker, the
`system including heating means, is provided. The cigarette
`includes a carrier having first and second ends spaced apart
`in a longitudinal direction and having first and second
`surfaces. The first surface defines a cavity between the
`25 first and second ends, and the second surface includes an
`area for being disposed adjacent heating means. Tobacco
`flavor material is disposed on the first surface of the
`carrier. The tobacco flavor material generates the flavored
`tobacco response in the cavity for delivery to a smoker when
`the tobacco flavor material is heated by the heating means.
`The carrier and the tobacco flavor material allow transverse
`air flow into the cavity.
`In accordance with another aspect of the present
`invention, a lighter for use in combination with a removable
`35 cigarette in a smoking system that delivers a flavored
`tobacco response to a smoker is provided. The lighter
`includes a heater fixture for receiving, through a first
`
`30
`
`Ex. 2022-0005
`
`

`

`WO94/06314
`
`PCT/US93/08457
`
`-
`
`4
`
`-
`
`10
`
`15
`
`end, a removable cigarette. The heater fixture has means
`for providing a transverse flow of air to at least a portion
`of the cigarette. A plurality of electrical heater elements
`are disposed in the heater fixture. Each of the heater
`5 elements has a surface for being disposed adjacent a surface
`of the portion of the cigarette to which the transverse flow
`of air is provided. Means are provided for activating one
`or more of the plurality of electrical heating means such
`that a predetermined quantity of flavored tobacco response
`is generated in the cigarette. The transverse flow of air
`is generated when a smoker draws on a cigarette inserted in
`the lighter.
`In accordance with another aspect of the present
`invention, a smoking system for delivering a flavored
`tobacco response to a smoker is provided. The system
`includes a removable cigarette, a lighter, and, means for
`individually activating the plurality of electrical heating
`means such that a predetermined quantity of flavored tobacco
`response is generated in a cavity in the cigarette.
`In accordance with yet another aspect of the
`present invention, a heater element for use in a smoking
`system for delivering a flavored tobacco response to a
`smoker is provided. The heater element includes a first
`end, a second end, and a plurality of curved regions between
`the first and second ends for increasing electrical
`resistance of the heater element. The heater element is
`formed from resistive material having first and second
`surfaces substantially oriented in a plane and having an
`overall length L, overall width W, and thickness T. The
`30 effective electrical length of the heater element is greater
`than the length Land the effective electrical cross(cid:173)
`sectional area of the heater element is less than the prod(cid:173)
`uct of wand T.
`In accordance with still another aspect of the
`35 present invention, a method for manufacturing an integrated
`heater assembly for use in a smoking system for delivering a
`flavored tobacco response to a smoker is described.
`
`20
`
`25
`
`Ex. 2022-0006
`
`

`

`WO94/06314
`
`PCT/US93/084S7
`
`- 5 -
`According to the method, a sheet of resistive material is
`cut to form a plurality of heater elements connected to one
`another at at least one end. The sheet is formed into a
`cylindrical shape.
`
`10
`
`5 Brief Description of the Drawings
`The present invention can be further understood
`with reference to the following description in conjunction
`with the appended drawings, wherein the same elements are
`provided with the same reference numerals.
`In the drawings:
`FIG. 1 is a schematic perspective view of a
`smoking system according to an embodiment of the present
`invention;
`FIG. 2 is a partially broken, schematic
`perspective view of a smoking system according to an
`15 embodiment of the present invention;
`FIG. 3A is a side, cross-sectional view of a
`heater fixture according to an embodiment of the present
`invention;
`FIG. 3B is an end view of taken at section 3B-3B
`20 of FIG. 3A;
`FIG. 4A is a schematic perspective view of a
`cigarette according to an embodiment of the present
`invention;
`FIG. 4B is a side cross-sectional view taken at
`25 section 4B-4B of FIG. 4A;
`FIG. 5 is a schematic assembly view of a heater
`fixture according to another embodiment of the present
`invention;
`FIC .. 6 is a perspective view of a heater assembly
`30 according to an embodiment of the present invention;
`FIG. 7 is an outline of a heater assembly
`according to an embodiment of the present invention;
`FIG. 8 is a perspective view of a portion of a
`heater element according to an embodiment of the present
`invention;
`
`35
`
`Ex. 2022-0007
`
`

`

`WO94/06314
`
`PCT/US93/08457
`
`5
`
`10
`
`-
`6 -
`FIG. 9 is a perspective view of a pin assembly
`according to an embodiment of the present invention;
`FIG. l0A is a schematic, side cross-sectional view
`of a spacer according to an embodiment of the present
`invention;
`FIG.' l0B is a schematic view taken at section 10B-
`lOB of FIG. lOA;
`lOC is a schematic view taken at section l0C-
`FIG.
`l0C of FIG. l0A; -
`FIG. llA is a schematic, side cross-sectional view
`of a base according to an embodiment of the present
`invention;
`FIG. 11B is a schematic view taken at section 11B(cid:173)
`llB of FIG. llA;
`F~G. llC is a schematic view taken at section llC-
`llC;of FIG. llA;
`~
`FIG. 12A is a schematic, perspective view of a
`combined spacer base member according to an embodiment of
`the present invention;
`FIG. 12B is a schematic, side cross-sectional view
`taken at section 12B-12B of FIG. 12A;
`FIG. 12C is a schematic view taken at section 12C-
`12C of FIG. 12A;
`FIG. 12D is a schematic view taken at section 12D-
`25 12D of FIG. 12A;
`FIG. 13 is an end view of a ring according to an
`embodiment of the present invention;
`FIG. 14A is a schematic, perspective view of a cap
`according to an embodiment of the present invention;
`FIG. 14B is a schematic, side cross-sectional view
`taken at secti_on 14B-14B of FIG. 12A;
`FIG. 14C is a schematic view taken at section 14C-
`14C of FIG. 14A;
`FIG. 14D is a schematic view taken at section 14D-
`35 14D of FIG. 14A;
`FIG. 15A is a schematic side view of a heater
`sleeve according to an embodiment of the present invention;
`
`15
`
`20
`
`30
`
`Ex. 2022-0008
`
`

`

`WO94/06314
`
`PCT/US93/08457
`
`- 7 -
`
`5
`
`FIG. 15B is an end view taken at section 15B-15B
`of FIG. 15A;
`FIGS. 16 and 17 are schematic side cross-sectional
`views of portions of a smoking system showing air flow paths
`in the smoking system;
`FIG. 18 is a schematic circuit diagram showing
`circuitry according to an embodiment of the invention;
`FIG. 19 is a schematic, cross-sectional side view
`of a smoking system according to a further embodiment of the
`10 present invention;
`FIG. 20 is a schematic, cross-sectional side view
`of a heater fixture according to a further embodiment of the
`present invention;
`FIG. Zl is a schematic perspective view of an
`15 apparatus for manufacturing a center portion of a disposable
`·' - cigarette of the smoking system of FIG. 19;
`FIG. 22 is a schematic, cross-sectional side view
`of a "peripheral draw" embodiment of a smoking system
`according to the present invention;
`FIG. 23 is a schematic circuit diagram showing
`circuitry according to a further embodiment of the
`invention; and
`FIG. 24 is a schematic circuit diagram of a timing
`network of the control circuit of FIG. 23.
`
`20
`
`25 Detailed Description
`A smoking system 21 according to the present
`invention is seen with reference to FIGS. 1 and 2. The
`smoking system 21 includes a cigarette 23 and a reusable
`lighter 25. The cigarette 23 is adapted to be inserted in
`30 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
`35 cycles as the cigarette 23.
`
`Ex. 2022-0009
`
`

`

`WO94/06314
`
`PCT/US93/08457
`
`-
`
`8 -
`
`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
`5 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
`10 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
`15 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
`20 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
`(actually 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
`30 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 power sources and quick-discharging capacitor power
`sources that are charged by batteries, and is hereby
`incorporated by reference.
`
`25
`
`35
`
`Ex. 2022-0010
`
`

`

`WO94/06314
`
`PCT/US93/08457
`
`-
`
`9 -
`
`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
`5 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.
`In the presently preferred embodiment, the heating
`fixture 39 includes eight radially spaced heating elements
`10 43, seen in FIG. 3A, that are individually energized by the
`power source 37 under the control of the circuitry 41 to
`heat eight areas around the periphery of the cigarette 23 to
`develop eight puffs of a flavored tobacco response. While
`other numbers of heating elements 43 may be provided, eight
`15 heater elements are preferred, at least because there are
`nominally eight puffs on a conventional cigarette and
`because eight heater elements lend themselves to electrical
`control with binary devices.
`The circuitry 41 is preferably activated by a
`20 puff-actuated sensor 45, seen in FIG. 2, that is sensitive
`either to pressure changes or air flow changes 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 47
`extending through a spacer 49 and a base 50 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
`30 disclosure of which is incorporated by r·,:.ference, and is in
`the form of a .Mode:; 163PC01D35 silicon sensor, manufactured
`by the Microswitch division of Honeywell, Inc., Freeport,
`Ill., which activates an appropriate one of the heater
`elements 43 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 s~ccessfully demonstrated to be useful for
`
`35
`
`25
`
`Ex. 2022-0011
`
`

`

`WO94/06314
`
`PCT/US93/08457
`
`5
`
`- 10 -
`activating an appropriate one of the heater elements 43 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 ilvcthe :tighter. The indicator 51 preferably
`includes aL seven-segment liquid crystal display.
`In the
`presently preferred embodiment, the indicator 51 displays
`the digit 11 8 11 when a light beam emitted by a light sensor
`10 53, seen in FIG. 2, 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 55 in
`the spacer 49 and the base 50 of the heater fixture 39,
`seen, for example, in FIG. 3A. The light sensor 53 provides
`15 a signal to the circuitry 41 which, in turn, provides a
`signal to the indicator 51. 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 ,~lements 43 have been activated to heat the new
`20 cigarette. After the cigarette 23 is fully smoked, the
`indicator displays the digit 11 011 • 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
`25 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
`OPTEK Technology, Inc., 1215 West Crosby Road, Carrollton,
`30 Texas 75006.
`As one of several possible alternatives to using
`the above-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
`35 provided for resetting the circuitry 41 when a new cigarette
`is.inserted in the lighter 25, e.g., to cause the indicator
`51 to display the digit 11 8 11 , etc. Power sources, circuitry,
`
`Ex. 2022-0012
`
`

`

`WO94/06314
`
`PCT/US93/08457
`
`- 11 -
`puff-actuated sensors, and indicators useful with the
`smoking system 21 of the present invention are described in
`U.S. Patent No. 5,060,671, which is incorporated by
`reference. The passageway 47 and the opening 55 in the
`5 spacer 49 _and the heater fixture base 50 are preferably air(cid:173)
`tight during smoking.
`A presently preferred cigarette 23 for use with
`the smoking system 21 is seen in detail in FIGS. 4A and 4B,
`although the cigarette may be in any desired form capable of
`10 generating a flavored tobacco response for delivery to a
`smoker when the cigarette is heated by the heating elements
`43. 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
`15 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
`20 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,
`25 preferably a paper with a tobacco flavor coating, or a
`tobacco-based paper to enhance the tobacco flavor of the
`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
`30 base weight and caliper while providing sufficient tensile
`strength for ~achine processes. Presently preferred
`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
`35 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
`
`Ex. 2022-0013
`
`

`

`WO94/06314
`
`PCT/US93/084S7
`
`- 12 -
`
`strength~ 2000 grams/27 mm width (1 in/min), caliper 1.3 -
`1.5 mils, caco3 content~ 5%, citrate 0%. Materials for
`forming the overwrap paper 69 preferably include~ 75%
`tobacco-based sheet (non-cigar, flue- or flue-/air-cured mix
`5 filler and hright 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
`10 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
`15 cylindrical 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 71 and the second free-flow filter are secured to one
`another by tipping paper 75. The tipping paper 75 extends
`20 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-flow filter. 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
`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
`35 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
`
`30
`
`25
`
`Ex. 2022-0014
`
`

`

`WO94/06314
`
`PCT/US93/084S7
`
`- 13 -
`
`developed from the heated tobacco flavor material and air
`drawn in from outside the cigarette 23 during drawing on the
`cigarette, r.esulting in an improved flavored tobacco
`response and facilitating exposure of more of an end of the
`5 mouthpiece filter 71 to the mixed aerosol. The flavored
`tobacco response developed by heating the tobacco flavor
`material 61 is understood to be primarily in a vapor phase
`in the cavity 79 and to turn into a visible aerosol upon
`mixing in the passage 77.
`In addition to the above-
`10 described first free-flow filter 65 having a longitudinal
`passage 67, other arrangements capable of generating the
`desired mixing of the vapor phase flavored tobacco response
`with introduced air include those in which a first free-flow
`filter is provided in the form of a filter having a
`15 multitude of small orifices, i.e., the first free-flow
`filter may be in the form of a honeycomb or a metal plate
`having multiple holes formed therein.
`Air is preferably drawn into the cigarette 23
`predominantly through the tobacco web 57 and the overwrap
`20 paper 69, in a transverse or radial path, and not through
`the back-flow filter 63 in a longitudinal path. As
`explained below, however, it is desirable to permit air flow
`through the back-flow filter during a first puff on the
`cigarette to lower the RTD.
`It is presently understood that
`25 drawing air into the cigarette 23 longitudinally tends to
`r.esult in the aerosol developed by heating the tobacco web
`7 with the heater elements 43 arranged radially around the
`tobacco web not being properly removed from the cavity 79.
`It is presently preferred to produce a flavored tobacco
`response as a function almost entirely of the makeup of the
`tobacco web 57 and the energy level of the heater elements
`43. Accordingly, the portion of the air flow through the
`cigarette resulting from longitudinal flow through the back(cid:173)
`flow filter 63 is preferably minimal during smoking, except
`35 during the first puff. Fu7ther, the back-flow filter 63
`preferably minimizes the flow of aerosol in a backward
`direction out of the cavity 79 after heating of the tobacco
`
`30
`
`Ex. 2022-0015
`
`

`

`WO94/06314
`
`PCT/US93/08457
`
`- 14 -
`
`5
`
`flavor material 61, so that the potential for damage to
`components of the lighter 25 from aerosol flowing backward
`from the cigarette 23 is minimized.
`The carrier or plenum 59 which supports the
`tobacco flavor material 61 provides a separation between the
`heating elements 43 and the flavor material, transfers heat
`generated by the heater elements to the flavor material, and
`maintains cohesion of the cigarette after.smoking.
`Preferred carriers 59 include those composed of a non-woven
`10 carbon fiber mat, preferred because of its thermal
`stability. Such carriers are discussed in greater detail in
`copending commonly-assigned United States Patent Application
`Serial No. 07/943,747, filed September 11, 1992, which is
`incorporated by reference. Such mats should preferably have
`15 a thickness between about o.os~mm and about 0.11 mm and be
`composed of nonwoven carbon fibers (having a basis weight in
`the range of from about 6 g/m2 to about 12 g/m2 with fiber
`diameters between about 7 µm and about 30 µm). The lengths
`of the fibers should allow the mat to withstand the tensile
`20 stresses encountered during processing. Preferably, the
`mats should include a binder which is suitable for use in
`electric smoking articles (i.e., having acceptable
`subjective properties).
`Other carriers 59 include low mass, open mesh
`25 metallic screens or perforated metallic foils. For example,
`a screen having a mass in the range from about 5 g/m2 to
`about 15 g/m2 and having wire diameters in the range from
`about 0.038 mm (about, 1.5 mils) to about 0.076 mm (about 3.0
`mils) is used. Another embodiment of the s