Europaisches Patentamt
`
`European Patent Office
`
`Office europeen des brevets
`
`@ Publication number:
`
`0 358 002
`A2
`
`©
`
`EUROPEAN PATENT APPLICATION
`
`@ Application number: 89115028.6
`
`@ Int. c1.s: A24F 47/00
`
`@ Date of filing: 15.08.89
`
`@ Priority: 08.09.88 US 242086
`
`@ Date of publication of application:
`14.03.90 Bulletin 90/11
`® Designated Contracting States:
`AT BE CH DE ES FR GB GR IT LI LU NL SE
`
`@ Applicant: R.J. REYNOLDS TOBACCO
`COMPANY
`401 North Main Street
`Winston-Salem North Carolina 27102(US)
`
`@ Inventor: Brooks, Johnny Lee
`817 South Hawthorne Road
`Winston-Salem North Carolina 27103(US)
`Inventor: Roberts, Donald Leroy
`631 Chester Road
`Winston-Salem North Carolina 27104(US)
`Inventor: Simmons, Jerry Scott
`140 Prestwick Lane
`Rural Hall North Carolina 27045(US)
`Inventor: Morrison, Carl Christopher
`3175 Kittering Lane
`Winston-Salem North Carolina 27105(US)
`
`@ Representative: Hoeger, Stellrecht & Partner
`Uhlandstrasse 14 c
`O· 7000 Stuttgart 1 (DE)
`
`@ Smoking articles utilizing electrical energy.
`
`® Smoking articles employ an electrical resistance
`heating element and an electrical power source to
`provide a tobacco-flavored smoke or aerosol and
`other sensations of smoking. The smoking articles
`advantageously comprise a disposable portion and a
`reusable controller. The disposable portion, which
`N may be a cigarette, normally includes (i) an air
`<(permeable resistance heating element having a sur·
`Nface area greater than 1 m2/g, which usually carries
`Q an aerosol forming material, and (ii) a charge or roll
`Q of tobacco. The reusable controller normally includes
`CO a puff-actuated current actuation means, a time·
`~based current regulating means to control the tem-
`perature of the heating element, and a battery power
`Osupply.
`Q.
`LI.I
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`Xerox Copy Centre
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`FIG. I
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`SMOKING ARTICLES UTILIZING ELECTRICAL ENERGY
`
`BACKGROUND OF THE INVENTION
`
`The present invention relates to cigarettes and
`other smoking articles such as cigars, pipes, and
`the like, which employ an electrical resistance heat·
`ing element and an electrical power source to
`produce a tobacco-flavored smoke or aerosol.
`Preferred smoking articles of the invention are
`capable of providing the user with the sensations of
`smoking (eg., smoking taste, feel, satisfaction, plea(cid:173)
`sure. and the like), by heating but not burning
`tobacco, without producing sidestream smoke or
`odor, and without producing carbon monoxide. As
`used herein, the term "smoking article" includes
`cigarettes, cigars, pipes, and the like, which use
`tobacco in various forms.
`Many smoking articles have been proposed
`through the years as improvements upon, or alter·
`natives to, smoking products which burn tobacco.
`Many
`tobacco substitute smoking materials
`have been proposed, and a substantial listing of
`such materials can be found in U.S. Patent No.
`4,079,742 to Rainer et al. Tobacco substitute smok(cid:173)
`ing materials having the tradenames Cytrel and
`NSM were introduced in Europe during the 1970's
`as partial tobacco replacements, but did not realize
`any long-term commercial success.
`Numerous references have proposed smoking
`articles which generate flavored vapor and/or visi·
`ble aerosol. Most of such articles have employed a
`combustible fuel source
`to provide an aerosol
`and/or to heat an aerosol. See, for ex?mple, the
`background art cited in U:S. Patent No. 4,714,082
`to Banerjee et al.
`However, despite decades of interest and ef·
`fort, no one had successfully developed a smoking
`article which provided the sensations associated
`with cigarette or pipe smoking, without delivering
`considerable quantities of incomplete combustion
`and pyrolysis products.
`Recently, however, in European Patent Publica·
`tion Nos. 174,645 and 212,234, and U.S. Patent
`Nos. 4,708, 151, 4,714,082, and 4,756,318, assigned
`to A. J. Reynolds Tobacco Co., there are described
`smoking articles which are capable of providing the
`sensations associated with cigarette and pipe
`smoking, by heating but not burning tobacco, and
`without delivering considerable quantities of incom·
`plete combustion products. Such articles rely on
`the combustion of a fuel element for heat genera·
`tion, resulting in the production of some combus·
`tion products.
`Over the years, there have been proposed nu·
`merous smoking products, flavor generators and
`medicinal inhalers which utilize electrical energy to
`
`vaporize or heat a volatile material, or attempt to
`provide the sensations of cigarette or pipe smoking
`without burning tobacco.
`U.S. Patent No. 2,057,353 to Whittemore, Jr.
`proposed a vaporizing unit. In particular, a wick
`reportedly carried liquid medicament by capillary
`action to a point where the liquid was vaporized by
`an electrical resistance heating element.
`U.S. Patent No. 2, 104,266 to Mccormick pro·
`posed an article having a pipe bowl or cigarette
`holder which included a resistance coil (i) wound
`on an insulating and heat resisting material, and (ii)
`contained in an insulated chamber. Prior to use of
`the article, the pipe bowl was filled with tobacco or
`the holder was fit with a cigarette. Current then was
`passed through the resistance coil. Heat produced
`by the resistance coil was transmitted to the to·
`bacco in the bowl or holder, resulting in the vola·
`tilization of various ingredients from the tobacco. A
`thermostatic switch was employed to maintain a
`predetermined temperature range to which the to·
`bacco was heated.
`U.S. Patent No. 3,200,819 to Gilbert proposed
`a smokeless, non-tobacco cigarette having a flavor
`cartridge, such as a porous substrate impregnated
`with mentholated water. The article included a bat·
`tery for powering a tube or bulb which was illumi·
`nated before assembly. The bulb was placed in a
`tubular liner, which was in turn located within a
`tube of plastic having the size, color and form of a
`cigarette. In use, the illuminated bulb reportedly
`heated the flavored air drawn through passages
`formed between the bulb and the tubular liner. As
`such, warm, moist, flavored air was delivered to the
`user.
`French Patent Publication No. 2, 128,256 to
`Ribot et al proposed an article for delivering de·
`nicotinized smoke. The proposed article included a
`sealed ampule which contained pressurized de-
`nicotinized smoke. An electric resistor was
`im·
`mersed in the smoke. In use, the terminals of the
`resistor were pushed into contact with a microbat·
`tery causing the resistor to generate heat and heat
`the smoke within the ampule. Draw by the user
`reportedly caused warm smoke to exit a valve near
`the mouthend of the article.
`Japanese Patent Publication 8231173 to Takeda
`proposed a cigar-shaped inhaler which included a
`battery powered Nichrome wire to heat air that, in
`turn, evaporated an essence from an essence con·
`tainer. The Nichrome wire was energized by either
`a manually-actuated or a draw actuated "on-off"
`switch.
`West German Patent Application No. 2,653, 133
`to Kovacs proposed a smoking simulator having an
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`internal battery which could accelerate or control
`the vaporization or emission of aromatic sub·
`stances for delivery to the user. In supplemental
`West German Patent Application No. 2,704,218,
`Kovacs described the use of a vacuum or draw·
`actuated switch to switch "on" the battery operated
`heating coil.
`A draw actuated, pressure transducer switch
`was described in U.S. Patent No. 4,246,913 to
`Ogden et al, as part of a smoke aversion therapy
`article which delivered a small electrical shock to a
`smoker whenever the smoker drew on a cigarette.
`U.S. Patent No. 4, 141.369 to Burruss proposed
`an article similar
`to
`the previously discussed
`McCormick articles. Burruss proposed a container
`which was electrically heated to a temperature suf·
`ficient to volatilize desired components from smok·
`ing material inserted therein. Heated air passing
`through the container during draw reportedly car·
`ried volatilized materials to the mouth of the user.
`U.S. Patent No. 4,303,083 to Burruss proposed
`a pipe having an electrical resistance heating ele·
`ment, a manually operated "on-off" power switch,
`and an opening above the resistance element for
`the addition of volatile compound. During use, the
`volatile compound was applied, using a squeeze
`tube or eye dropper, to a heated surface within the
`pipe, apparently on a puff-by-puff basis. The vola·
`tile compounds reportedly were vaporized, mixed
`with air drawn into the pipe, and inhaled by the
`user.
`PCT Publication No. WO 86102528 to Nilsson
`et al proposed an article similar to that described
`by McCormick. Nilsson et al proposed an article for
`releasing volatiles from a tobacco material which
`had been treated with an aqueous solution of so·
`dium carbonate. The article resembled a cigarette
`holder and reportedly included a battery operated
`heating coil to heat an untipped cigarette inserted
`therein. A switch was activated to supply current to
`the heating coil. A temperature sensor reportedly
`disconnected and reconnected the battery in order
`to maintain the temperature generated by the de·
`vice in a narrow temperature range. Air drawn
`through the device reportedly was subjected to
`elevated temperatures below the combustion tern·
`perature of tobacco and reportedly liberated to·
`bacco flavors from the treated tobacco contained
`therein.
`U.S. Patent No. 4,735,217 to Gerth et al pro·
`posed a "cigarette-shaped" medicament dosing ar·
`ticle having a pellet of vaporizable medicament and
`a Nichrome resistance heating element connected
`in series with a battery power source and a draw
`actuated switch. In their only working example, the
`Nichrome heating element allegedly achieved a
`temperature in the range of 190 • F to 220' F (90' C
`to 105' C) within a two second puff, which appar·
`
`ently was sufficient to volatilize menthol from a
`menthol pellet. At Column 8, lines 43-63, Gerth et
`al. went on to speculate that their article could be
`used to vaporize nicotine from a nicotine-containing
`pellet and that they believed it feasible to coat the
`heating element with a nicotine-containing com·
`pound in lieu of using a vaporizable pellet.
`However, it is believed that it would not be
`possible to coat a Nichrome heating element, of
`the type described by Gerth et al. with enough
`vaporizable liquid material to deliver sufficient vela·
`tile material to the user. over the 6 to 10 puff life of
`a typical cigarette. It also is believed that the article
`of Gerth et al would not be able to provide enough
`electrical energy to (i) vaporize volatile material
`until near the end of a typical two second puff, or
`(ii) provide a high enough temperature (e.g., 150' C
`to 350' C) to vaporize many volatile materials with·
`in a two second puff, including many desirable
`aerosol forming substances and most volatile to·
`bacco flavor components. In addition, even with
`only a single AA battery, the article described by
`Gerth et al. is more than 3 times the diameter and
`many times heavier than a typical cigarette and is
`provided with a relatively imprecise draw actuated
`control switch and with no means of regulating the
`current or heat during the puff.
`Despite many years of interest and effort, none
`of the foregoing articles employing electrical en·
`ergy has ever realized any significant commercial
`success, and it is believed that none has ever been
`widely marketed. Moreover, it is believed that none
`of the foregoing electrical energy articles is ca·
`pable of providing the user with the sensations of
`cigarette or pipe smoking.
`Thus, it would be desirable to provide a smok·
`ing article which can provide the sensations of
`cigarette or pipe smoking, which does not burn
`tobacco or other material, and which does not
`produce combustion products.
`
`SUMMARY OF THE INVENTION
`
`The present invention relates to cigarettes and
`other smoking articles which employ an electrical
`resistance heating element and an electrical power
`source to provide a tobacco-flavored smoke or
`aerosol and other sensations of smoking, without
`burning tobacco or other substances, without pro(cid:173)
`ducing any combustion or pyrolysis products in·
`eluding carbon monoxide or any sidestream smoke
`or odor. Preferred articles can produce aerosol
`almost immediately upon commencement of a puff,
`as well as provide the controlled production of
`aerosol throughout the puff and over the 6 to 10
`puff life of a typical cigarette.
`In one aspect of the invention, the smoking
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`article includes a cigarette or a disposable portion
`(eg., a cartridge) which utilizes an air permeable
`high surface area electrical resistance heating ele·
`ment that normally carries aerosol forming and/or
`tobacco flavor substances prior to use. This resis·
`tance heating element typically is a porous material
`having a surface area greater than 1 m2/g, as
`determined using the Brunaver, Emmett and Teller
`(BET) method described in J. Am. Chem. Soc.,
`Vol. 60, p. 309 (1968); and AdsorPITOn Surface Area
`and Porosity, Gregg et al, Academic Press, NY
`(1967). Preferably, the heating element is a fibrous
`carbon material, most preferably having a surface
`area greater than about 1,000 m2/g. (In contrast,
`the surface area of the Nichrome metal resistance
`element of Gerth et al is believed to be about 0.01
`m2tg.) Preferably, such porous heating elements
`are impregnated with liquid aerosol forming sub·
`stances, such as glycerin, and with tobacco ex(cid:173)
`tracts. Such heating elements are particularly ad(cid:173)
`vantageous in that they are capable of holding and
`efficiently releasing relatively large quantities of
`liquid aerosol forming substances and tobacco fla(cid:173)
`vor materials. For example, such heating elements
`can carry enough aerosol forming substances to
`provide aerosol for 6 to 10 puffs, or more.
`The cigarette or disposable portion includes
`tobacco, such as a roll or charge of cut filler. Other
`forms of tobacco also can be used.
`Another aspect of the invention relates to a
`reusable controller which can be used with the
`cigarettes or disposable portions of the invention,
`as well as with other resistance heating aerosol
`producing articles. This reusable controller normal·
`ly includes a current actuation means, a separate
`current regulating means to control the temperature
`of the heating element, and a battery power supply.
`Alternatively, the electrical power supply can be
`provided separately from the current actuation and
`current regulating means; e.g., as a separate bat(cid:173)
`tery pack or as normal household current stepped
`down by an appropriate transformer. The reusable
`controller can be in the form of a pipe, a reusable
`cigarette holder, or a hand-held unit or other porta·
`ble form into which the disposable portion can be
`inserted. The use of such a reusable article with
`the cigarette and disposable portions of the inven·
`tion is particularly advantageous in that it permits
`the use of (i) relatively large power sources, ca·
`pable of generating 1 O to 40 watts of power 'Jr
`more, and (ii) accurate and sophisticated current
`actuation and current regulating means that nor·
`mally would be too costly to incorporate into a
`single use, disposable article.
`Preferably, the current actuation means is puff
`actuated, so that current flows through the resis(cid:173)
`tance heating element to produce aerosol only dur·
`ing draw by the user.
`
`The current regulating means normally func(cid:173)
`tions only during periods of current actuation, and
`preferably is time based. That is, the current regu·
`lating means preferably is based on controlling the
`time period during which current passes through
`the resistance element during draw. This, in turn,
`controls the temperature experienced by the resis(cid:173)
`tance element and by the aerosol forming sub(cid:173)
`stances. The current regulating means normally
`includes an electrical control circuit which maxi·
`mizes initial heating of the heating element. until a
`desired temperature range for volatilization of the
`aerosol former and the tobacco flavor substances
`is reached, usually between about 150 • C and
`about 350' C. Thereafter, the control circuit, by
`regulating, restricting or interrupting current flow
`through the resistance element, normally maintains
`the heating element within the desired temperature
`range during the balance of the puff and/or ensures
`that the heating element does not overheat during
`puffing.
`Preferably, the time-based current regulating
`means includes a means for permitting uninter(cid:173)
`rupted current flow through the heating element for
`an initial period after current actuation, thus permit·
`ting rapid heating of the resistance element. The
`current regulating means preferably includes a tim(cid:173)
`er means for subsequently regulating or interrupt·
`ing current flow through the heating element. such
`as by repeated off·on switching, to control the
`average current flow through the heating element
`during the balance of the puff. This, in turn, con(cid:173)
`trols the temperature range experienced by the
`heating element. More preferably, the current regu-
`lating means also includes a means to prevent the
`heating element from overheating during rapid puff(cid:173)
`ing.
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`Depending upon factors such as the wattage
`generated by the power source and the resistivity
`of the heating element, preferred current regulating
`means of the invention are capable of producing
`almost immediate aerosol generation upon puffing,
`preferably within about 0.5 second, more preferably
`within about 0.1 second. Such preferred regulating
`45 means also ensure that sufficient aerosol forming
`and
`tobacco flavor substances remain
`for
`later
`puffs, and that such substances are not degraded
`by exposure to excessive temperatures.
`To use the smoking articles of the inver.ltion,
`the user simply inserts the cigarette or disposable
`portion into the controller, to electrically connect
`the heating element to a circuit including the cur(cid:173)
`rent actuation and current regulating means and to
`the battery. When the user draws on the mouthend
`of the article, the preferred current actuation and
`current regulating means permit unrestricted or un(cid:173)
`interrupted
`flow current through
`the resistance
`heating element to generate heat rapidly. This
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`heating volatilizes the aerosol forming and/or to(cid:173)
`bacco flavor substances, which in turn form an
`aerosol and pass through th~ article and into the
`mouth of the user. At the same time, the current
`regulating means (i) regulates current flow through
`the heating element to control heating of the resis(cid:173)
`tance element and the temperature experienced
`thereby, and (ii) prevents overheating and degrada(cid:173)
`tion of the aerosol former. When the user stops
`drawing on the article, the current actuation means
`prevents further current flow through the heating
`element and disables the current regulating means.
`This process continues, puff after puff, until the
`user decides to stop drawing on the article. At that
`point. the cigarette or reusable portion can be
`removed and discarded, and a new one inserted in
`its place.
`Another important aspect of the invention re(cid:173)
`lates to the various configurations of the cigarette
`or disposable portions described herein. For exam(cid:173)
`ple, in certain preferred embodiments, the dispos(cid:173)
`able portion advantageously is provided with an
`electrical connection means at one end thereof.
`This electrical connection means includes means
`for connecting the resistance element to the battery
`or other external power source, and preferably in(cid:173)
`cludes an air passageway used in conjunction with
`the preferred puff actuated current actuation
`means. In other preferred embodiments, the dis(cid:173)
`posable portion is adapted for connection to the
`external power source via connectors located on
`the reusable controller. In certain preferred embodi(cid:173)
`ments, the resistance heating element is located
`centrally in the disposable portion and/or does not
`occupy a significant portion of the cross-sectional
`area of the disposable portion. In other preferred
`embodiments, the resistance heating element is
`located adjacent an end of the disposable portion,
`andior at least substantially fills the cross-sectional
`area of the disposable portion or the air passage(cid:173)
`way therethrough.
`In another aspect of the invention, the current
`actuation means,
`the current regulating means,
`and/or the electrical power source may be incor(cid:173)
`porated into the portion of the smoking article con(cid:173)
`taining the electrical resistance heating element, so
`that the reusable controller may be reduced in size
`or even eliminated.
`Yet another aspect of the invention relates to a
`current control circuit for resistance heating aerosol
`producing articles which includes the current regu(cid:173)
`lating means described herein.
`Preferred smoking articles of the invention are
`capable of delivering an average of at least 0.5 mg,
`more preferably at least 0.8 mg, of aerosol per
`puff, measured as wet
`total particulate matter
`(WTPM), under standard FTC smoking conditions
`of 2 second, 35 ml puffs, taken once every 60
`
`seconds. Preferred smoking articles of the inven(cid:173)
`tion can deliver such aerosol, preferably in visible
`form, for a plurality of puffs, preferably at least
`about 6 puffs, more preferably at least about 10
`puffs, under such conditions.
`Smoking articles of the invention also are ca(cid:173)
`pable of providing an aerosol which is chemically
`simple. A chemically simple aerosol consists es(cid:173)
`sentially of air,
`the aerosol
`former,
`tobacco
`volatiles, and desired flavorants. This aerosol pref(cid:173)
`erably has no significant mutagenic activity accord(cid:173)
`ing
`to
`the Ames test; Ames et al, Mut. Res.,
`31 :347-364 (1975); Nagao et al, Mut. Res., 42:335
`(1977).
`-
`-
`As used herein, and only for the purposes of
`this application, "aerosol" is defined to
`include
`vapors, gases, particles, and the like, both visible
`and
`invisible, and especially those components
`perceived by the user to be "smoke-like," gen·
`erated by action of heat from the resistance heat(cid:173)
`ing element upon aerosol
`forming substances
`and/or tobacco flavor substances located on the
`resistance element or elsewhere in the article.
`The articles of the present invention are de-
`scribed in greater detail in the accompanying draw(cid:173)
`ings and in the detailed description of the invention
`which follows.
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`BRIEF DESCRIPTION OF THE DRAWINGS
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`Figure 1 is a longitudinal, partial sectional
`view of a smoking article of this invention;
`Figure 1 A is a sectional view of a portion of
`the embodiment shown in Figure 1 taken along
`lines 1-1;
`Figure 2 is a longitudinal, partial sectional
`view of a smoking article of this invention;
`Figure 3 is a perspective of a smoking article
`of this invention including an exposed inner view of
`the reusable portion thereof;
`Figures 4, 5, and 6 are longitudinal, partial
`sectional views of preferred smoking articles of this
`invention showing the disposable portions and cut-
`away views of the controllers;
`Figures 7 and 8 are longitudinal sectional
`views of additional smoking articles of the inven(cid:173)
`tion;
`
`Figures 9 and 1 O are representative sche·
`50 matic 'iiagrams of time-based control circuits and
`related wiring for preferred controllers of the inven(cid:173)
`tion; and
`Figure 11 depicts the temperature, average
`current and average voltage profiles experienced
`by a resistance heating element during heating
`controlled by
`the preferred current
`regulating
`means of the invention.
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`DETAILED DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`- - - - - - - -
`
`Referring to Figure 1, smoking article 10 in·
`eludes a cigarette 12 and a reusable, hand-held
`controller 14. The cigarette 12 includes electrical
`connection plug 16, resistance heating element 18
`carrying an aerosol forming substance, a roll of
`tobacco 20, mouth end filter 22, and a resilient
`overwrap 24. The preferred controller 14 includes a
`case 26, a puff actuated current actuation mecha·
`nism 28 having the form of a pressure sensitive
`switch, a time-based current control circuit 30. and
`a chamber 32 into which battery power supply 34
`(shown as batteries 34A and 348) is inserted.
`The resistance heating element 18 employed
`in cigarette 12 preferably is a fibrous material hav·
`ing a high surface area and an adsorbant. porous,
`wettable character, in order to carry a suitable
`amount of aerosol forming substance for effective
`aerosol formation. Suitable heating elements pref·
`erably have surface areas above about 50 m21g,
`more preferably above about 250 m2/g, and most
`preferably above about 1,000 m2ig:
`Preferred heating elements normally have low
`mass, low density, and moderate resistivity, and
`are thermally stable at the temperatures exper·
`ienced during use. Such heating elements heat and
`cool rapidly, and thus provide for the efficient use
`of energy. Rapid heating of the element also pro·
`vides almost immediate volatilization of the aerosol
`forming substance. Rapid cooling prevents sub·
`stantial volatilization
`(and hence waste) of
`the
`aerosol forming substance during periods when
`aerosol formation is not desired. Such heating ele·
`ments also permit relatively precise control of the
`temperature range experienced by the aerosol for·
`ming substance, especially when
`the preferred
`time based current control means of the invention
`is employed.
`Preferred resistance heating elements include
`carbon
`filament yarns available
`from American
`Kynol, Inc., New York, NY, as Catalog Nos. CFY·
`0204·1, CFY-0204·2, and CFY-0204·3. Such yarns
`typically have surface areas of about 1 ,500 m2/g
`and resistivities of about 10 to about 30 milliohm·
`cm. See, Kirk·Othmer: Encycl. Chem. Tech., vol.
`16, 3rd Ed., pp. 135·136 (1981 ). Representative
`lengths of such yarns range from about 15 mm to
`about 50 :nm. Other preferred 20 heating elements
`felts
`felts and activated carbon
`include carbon
`available from American Kynol, Inc., as Catalog
`Nos. CN·157(HC). CN·210(HC), ACN-211-10, ACN·
`210-10, and ACN-157·10. Such felts typically have
`surface areas of about 1,500 m2tg and resistivities
`of about 5 to about 30 milliohm-cm. Such felts can
`be used in the form of circular discs having diam·
`eters of about 4 to 8 mm, as described in greater
`
`5
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`detail hereinafter with reference to Figures 4·6.
`Other suitable heating elements include porous
`metal wires or films; carbon yarns, cloths, fibers,
`discs or strips; graphite cylinders, fabrics or paints;
`microporous high
`temperature polymers having
`moderate resistivities: porous substrates in intimate
`contact with resistance heating components; and
`the like.
`Preferably, the heating element 18 is imp reg·
`nated with or otherwise carries the aerosol forming
`substance in order that the aerosol forming sub·
`stance is in a heat exchange relationship with the
`electrical heating element. The aerosol
`forming
`substance can be, for example, a polyhydric al·
`cohol, such as glycerin, propylene glycol, or a
`mixture thereof; water; a tobacco material such as
`a tobacco aroma oil, a tobacco essence, a spray
`dried tobacco extract, a freeze dried tobacco ex(cid:173)
`tract. tobacco dust, or the like, in order to provide
`tobacco flavor; or a combination
`thereof. Other
`suitable aerosol forming substances are well known
`in
`the art. See, for example, U.S. Patent Nos.
`4,714,092 and 4,756,318. While the loading of the
`aerosol forming substance can vary from sub·
`stance to substance and from heating element to
`heating element, the amount of liquid aerosol for(cid:173)
`ming substance used typically will be greater than
`about 15 mg and preferably ranges from about 25
`mg to about 50 mg.
`A heat resistant, electrically insulative strip,
`tube or spacer 36, preferably is provided in order
`to maintain the heating element in place and to
`prevent the heating element from contacting itself.
`The insulative spacer 36 can be a heat resistant
`plastic material (such as a polyimide), a cellulosic
`sheet treated with fire retardant, an aluminum foil
`having a surface coating of aluminum oxide, an
`insulative ceramic material, or the like.
`The electrical connection plug 16 preferably is
`40 manufactured from a resilient, electrically insulative
`material such as a thermoplastic material. The plug
`16 includes two electrical connector pins or prongs
`38, 39 connected to the ends of heating element
`18 via connectors 40, 41. The pins 38, 39 engage
`with electrical terminals 42, 43 located in electrical
`connection receptacle 44 of the controller 14. Plug
`16 also includes a passageway 46 through which
`tube 48 from pressure sensing switch 28 extends.
`As shown in Figure 1 A, pins 38, 39 and passage·
`way 46 are offset with respect to the longitudinal
`axis of plug 16.
`A portion of the length of the electrical connec·
`tion plug 16 preferably is circumscribed by a collar
`49 having the form of a thermoplastic tube, which
`preferably is friction fit around a portion of the
`length of the plug. The collar 49 in turn is secured
`to the remaining portion of the cigarette via over·
`wrap 24 using tipping paper 52 or other appropriate
`
`45
`
`50
`
`55
`
`6
`
`Fontem Ex. 2052
`R.J. Reynolds Vapor Company v. Fontem Holdings 1 B.V. IPR2018-00631
`Page 6 of 25
`
`

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`11
`
`EP 0 358 002 A2
`
`12
`
`means such as adhesive, a friction fit, or the like.
`Preferably, the collar 49
`includes one or more
`peripheral air inlet openings 54 which provide a
`flow of ambient air through the cigarette during
`draw. Alternatively, the air inlet can be positioned
`through the extreme inlet end of the cigarette or
`elsewhere through the periphery of the cigarette,
`such that drawn ambient air passing through the
`cigarette to the mouth of the user passes the
`resistance element.
`The cigarette can include a plug spacer mem·
`ber 55 positioned between the heating element 18
`and the roll or charge of tobacco 20. The plug
`spacer member 55 conveniently permits passage
`of aerosol therethrough, while preventing tobacco
`filler from contacting the heating element. The plug
`spacer member can be a cylindrical plug of pleated
`tobacco paper (eg., pleated tobacco paper of the
`type commercially available from Kimberly-Clark
`Corp. as P144-185-GAPF Reconstituted Tobacco
`Sheet). Preferably, the spacer member is over·
`wrapped with a paper overwrap 56.
`The tobacco charge 20 can be tobacco filler
`such as strands or shreds of tobacco laminae,
`reconstituted tobacco, volume expanded tobacco,
`processed tobacco stems, or blends thereof. Ex·
`truded tobacco materials and other forms of to·
`bacco, such as tobacco extracts, tobacco dust. or
`the
`like, also can be employed. Preferably, the
`tobacco charge 20 is overwrapped with a paper
`overwrap 57.
`flavor modifiers
`tobacco
`Tobacco extracts;
`such as levulinic acid; and other flavoring agents
`such as menthol, vanillin, chocolate, licorice, and
`the like; can be carried by the heating element,
`placed between the heating element and the spac·
`er member, applied to the spacer member, blend·
`ed with
`the tobacco charge, or applied to the
`mouthend filter.
`The mouthend filter 22 preferably is a low
`efficiency filter made from a melt blown thermo(cid:173)
`plastic such as polypropylene. For example, the
`filter can be manufactured by pleating a web of
`nonwoven polypropylene available from Kimberly·
`Clark Corp. as experimental melt blown, macrofiber
`polypropylene
`PP·1 OO·F.
`Alternatively,
`the
`mouthend filter 22 can be man