`United States Patent
`
`[19]
`
`USO0Sl44962A
`[11] Patent Number:
`
`5,144,962
`
`Counts et al.
`
`[45] Date of Patent:
`
`Sep. 8, 1992
`
`[54] FLAVOR-DELIVERY ARTICLE
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`[75]
`
`Inventors: Mary E. Counts; Mohammad R.
`Hajaligol, both of Richmond;
`Constance H. Morgan; Ulysses Smith,
`both of Midlothian; Francis M_
`sprinkel, Glen Allen; Francis V.
`Utsch, Midlothian, all of Va.
`
`4,735,217 4/ 1988 Gerth et al. ....................... .. 131/273
`4,922,901 5/ 1990 Brooks et al.
`.
`4,945,931
`8/1990 Gori .
`4,947,874 8/ 1990 Brooks et al. ‘.
`4,947,875
`8/I990 Bl'0OkS et 81.
`.
`FOREIGN PATENT DOCUMENTS
`
`Assignee:
`
`Philip Morris Incorporated, New
`York’ NY’
`
`Pr,-mmy Exam,-m,,_V_ Mini“
`Attorney, Agent, or Firm——Jeffrey H. Ingerman
`
`W090/03224 4/1990 PCT Int’l Appl.
`
`.
`
`App}. No.: 444,818
`
`Ffled,
`
`Dec 1, 1989
`
`Int. Cl.5 ............................................. .. A24D 1/00
`U.S. Cl. .................................. .. 131/194; 131/335;
`128/200,14; 128/202.21; 128/203,26;
`128/203,27; 128/204_13
`Field of Search ............. .. 131/270, 194, 195, 329,
`131/330, 335; 128/200.14, 202.21, 203.26,
`203.27, 204.13
`
`[57]
`
`ABSTRACT
`
`Methods and apparatus for releasing flavor components
`from a flavor-generating medium using an electric heat-
`ing element are provided. A nomcombustion flavor-
`generating article uses electrical energy to power a
`heating element which heats tobacco or other flavor-
`ants. The flavor-generating medium is formed into a
`packed bed. Energy delivered to the heating element is
`regulated to maintain the flavor-generating medium at a
`relatively constant operating temperature to ensure a
`relatively constant release of flavor.
`
`146 Claims, 9 Drawing Sheets
`
`VMR-Ex. 1011-001
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`
`Sep. 8, 1992
`
`Sheet 4 of 9
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`
`7/B4175/570:?
`TEMP
`
`VMR-Ex. 1011-005
`
`
`
`Sep. 8, 1992
`
`Sheet 5 of 9
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`5,144,962
`
`26 22 /3
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`VMR-Ex. 1011-006
`
`
`
`U.S. Patent
`
`Sep. 3, 1992
`
`She_et 5 of 9
`
`5,144,962
`
`_ + _
`0!/7/"I/7'
`65
`(70 #54 7/A/6
`£1015/V7)
`
`VMR-Ex. 1011-007
`
`
`
`Sep. 8, 1992
`
`Sheet 7 of 9
`
`5,144,962
`
`VMR-Ex. 1011-008
`
`
`
`US. Patent
`
`Sep. 8, 1992
`
`Sheet 8 of 9
`
`5,144,962
`
`VMR-Ex. 1011-009
`
`
`
`U.S. Patent
`
`Sep. 8, 1992
`
`Sheet 9 of 9
`
`5,144,962
`
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`
`1
`
`FLAVOR-DELIVERY ARTICLE
`
`BACKGROUND OF THE INVENTION
`
`5,144,962
`
`‘This invention, relates to electrically-heated flavor-
`delivery articles, and to methods and apparatus for
`electrically heating a flavor source in order to derive
`flavor therefrom.
`Smoking articles utilizing electrical power for heat-
`ing and thereby releasing flavor from tobacco and other
`compounds may have certain advantages over conven-
`tional smoking articles. For example, electrically-
`heated smoking articles produce the taste and sensation
`of smoking without burning of tobacco. Also, electri-
`cally-heated articles do not produce a visible aerosol
`between puffs. However, there have been various tech-
`nical problems with electrically-heated articles.
`It is desirable to maintain the smoking article at a
`substantially consistent temperature during operation to
`produce a relatively consistent release of flavor from
`puff to puff. The smoking article must reach operating
`temperature quickly, it must not overheat, and it must
`remain at the operational temperature long enough to
`generate/release designed flavors, vapors, and aerosols
`(hereinafter “flavor components”). The article should
`also be efficient in terms of its power consumption.
`SUMMARY OF THE INVENTION
`
`l5
`
`In view of the foregoing, it is an object of this inven-
`tion to provide an electrically-heated device for gener-
`ating flavor components.
`It is a more particular object of this invention to
`provide an electrically-heated article which reduces or
`eliminates certain byproducts of burning.
`It is another object of this invention to provide an
`electrically-heated article in which flavor components
`are consistently released from puff to puff.
`It is yet another object of this invention to provide an
`electrically-heated article which allows controlled fla-
`vor component delivery with a minimal amount of 40
`input energy.
`It is still another object of this invention to provide an
`electrically-heated article having a passive system for
`predictably controlling the temperature of the heating
`element.
`It is still another object of this invention to provide an
`electrically-heated article having an active system for
`predictably controlling the temperature of the heating
`element.
`These and other objects of the invention are accom-
`plished by providing electrically powered devices hav-
`ing a flavor-generating medium capable of generating-
`/releasing flavor components when heated, in heating
`element, a power source, and a control system for regu-
`lating the temperature of the flavor-generating medium
`or the amount of power applied to the heating element.
`The article of this invention releases a controlled
`amount of flavor components. A heating element raises
`the temperature of a flavor-generating medium to a
`predetermined temperature, which is below the temper-
`ature at which burning begins. For example, a non-
`burning article is formed by surrounding a positive
`temperature coefficient
`thermistor with the flavor-
`generating medium to be heated, capturing the material
`and heating element in a tube (which typically may be
`foil-lined), attaching a filter, and providing an outer
`wrapper for the article. The flavor-generating medium
`is heated by applying electrical energy to the thermis-
`
`2
`tor. The thermistor draws electrical current, which
`raises the temperature of the thermistor to some prede-
`termined “transition” temperature. The transition tem-
`perature is a known value, determined by the composi-
`tion of the thermistor, at which the device’s tempera-
`ture stabilizes.
`Alternatively, a control system applies a predeter-
`mined, timed voltage cycle to the heating element, or
`temperature cycle to the flavor-generating medium,
`pulsing the temperature of the medium to the preferred
`temperature to produce flavor components. This multi-
`stage operation reduces power consumption, because
`the flavor generator is at elevated temperatures for only
`short periods of time.
`In addition to providing flavor components for en-
`joyment, articles made in accordance with this inven-
`tion provide a means for regulating the delivery of the
`flavor components produced by the article. The amount
`of flavor released from the flavor-generating medium
`varies according to the temperature to which the fla-
`vor-generating medium is heated. By selecting heating
`elements, power supplies, and control systems with the
`proper operating characteristics, articles of different
`deliveries can be produced.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The above and other objects and advantages of the
`invention will be apparent upon consideration of the
`following detailed description,
`taken in conjunction
`with the accompanying drawings, in which like refer-
`ence numerals refer to like parts throughout, and in
`which:
`
`FIG. I is a partially fragmentary perspective view of
`an illustrative embodiment of a non-buming a.rticle
`made in accordance with the principles of this inven-
`tion;
`FIG. 2 is an alternative embodiment of the non-bum-
`
`ing article of FIG. 1;
`FIG. 3 is a longitudinal sectional view of another
`illustrative embodiment of a non-buming article con-
`structed in accordance with this invention; I
`FIG. 4 is a graph of the temperature characteristic of
`a typical thermistor used as a heat source for the non-
`burning article of this invention;
`FIG. 5 is a graph illustrating the power consumed by
`a thermistor to achieve and maintain the temperatures
`depicted in FIG. 4;
`FIG. 6 is a longitudinal sectional view of another
`illustrative embodiment of a non-burning article con-
`structed in accordance with this invention;
`FIG. 7 is a partially fragmentary longitudinal sec-
`‘ tional view of an illustrative embodiment of a non-bum-
`ing article constructed in accordance with this inven-
`tion having an active control circuit;
`FIG. 8 is an illustrative embodiment of the active
`control circuit of the article of FIG. 7;
`_
`FIG. 8a is an schematic diagram of an alternative
`active control circuit;
`FIG. 9 is a longitudinal sectional view of an illustra-
`tive embodiment of a non-buming smoking article
`which uses a capacitor and battery as a power supply;
`FIG. 10 is a schematic diagram of the electrical con-
`nections for the article of FIG. 9;
`FIG. 11 is a partly schematic diagram of a device
`constructed in accordance with this invention for sup-
`plying electrical energy to the articles of this invention;
`
`VMR-Ex. 1011-011
`
`
`
`5,144,962
`
`3
`FIG. 12 is an alternative embodiment of the device of
`FIG. 11;
`FIGS. 13 and 14 are perspective views of appliance-
`type devices for supplying electrical energy to the arti-
`cles of this invention;
`FIG. 15 is a longitudinal sectional view of an altema—
`tive embodiment of a non-burning article of this inven-
`tion;
`FIG. 16 is a partly schematic diagram of apparatus
`for heating the article of FIG. 15; and
`FIG. 17 is an alternative embodiment of the apparatus
`of FIG. 16.
`
`25
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`Referring now to the drawings, FIG. I shows an
`article, designated generally by reference numeral 10,
`which typically includes flavor-generating medium 12,
`a heating element 14, and a power source 16, which are
`surrounded by an outer tube or overwrapper 18. Fla-
`vor-generating medium 12 typically may be formed in a
`packed bed or as an extruded rod disposed around heat-
`ing element 14, and is then typically encased in an inner,
`therrnally-insulating tube 20. Flavor-generating me-
`dium 12 is captured within tube 20 by perforated front
`and rear clips 22 and 24, respectively. Electrical energy
`from power source 16 is applied to the terminals of
`heating element 14, which heats the flavor-generating
`medium to produce flavor components. Air holes 26 are
`provided in outer wrapper 18 to permit outside air to be
`drawn through flavor-generating medium 12. The out-
`side air mixes with the flavor components, and the mix-
`ture is drawn through from clip 22 and filter 28 when
`the consumer draws on the article. Article 10 is separa-
`ble along line A—A to permit the consumer to replace
`expended flavor-generating medium and filter materi-
`als, and to access power source 16.
`FIG. 2 shows an alternative embodiment of article 10
`
`in which energy is supplied to heating element 14 from
`an external source rather than from internal power
`source 16. Energy is transmitted to the contacts of heat-
`ing element 14 via connector pins 30. A heater base 32,
`which partially extends within tube 20, supports and
`properly positions connector pins 30. Energy may be
`supplied to connector pins 30 through wires extending
`to an external power source, permitting article 10 to be
`operated while the power is connected. Alternatively,
`the article may be plugged directly into the external
`power source while heating and then removed from the
`power source for use. One skilled in the art could mod-
`ify the embodiments of the articles described herein to
`utilize either internal or external power sources.
`Flavor-generating medium 12 typically is placed
`around heating element 14. Alternatively, the heating
`element may surround the flavor-generating medium.
`Flavor components are released from medium 12 when
`the temperature of medium 12 has been raised to be-
`tween about 100° C. and 500° C. The preferred tempera-
`ture range for generating flavor components is between
`120° C. and 400° C., and the most preferred range is
`between 200° C. and 350° C. The amount of flavor
`components produced by the article, and consequently,
`the amount of flavor released, depends upon the tem-
`perature, quantity, and concentration of flavor-generat-
`ing medium 12. Flavor-generating medium 12 may be
`similar to the flavor pellets shown in commonly as-
`signed U.S. patent application Ser. No. 07/222,831, filed
`Jul. 22, 1988, hereby incorporated by reference in its
`
`4
`entirety. Flavor-generating medium 12 may include
`tobacco or tobacco-derived materials. Alternatively,
`medium 12 may be peppermint, fruit flavors, or other
`similar flavors.
`Heating element 14 may be formed using a variety of
`materials. In a preferred embodiment, heating element
`14 is a resistive wire coil (such as tungsten, tantalum, or
`an alloy of nickel, chromium, and iron (such as that sold
`by Driver-Harris Company, Harison, N.J., under the
`trademark NICHROME ®) disposed within an insulat-
`ing tube which typically may be paper, foil, carbon,
`plastic, or glass. Alternatively,
`the heater may be
`formed with graphite or ceramics, and can be formed
`with a protective sheath of these materials.
`The heating element
`is designed to heat flavor-
`generating medium 12 directly or to heat outside air
`before it is drawn through medium 12. Referring now to
`FIG. 3, article 34 includes a first heating element 14 in
`contact with flavor-generating medium 12, and a sec-
`ond heating element 14’ for preheating air drawn into
`tube 20 before it enters bed 12. When a puff is drawn on
`filter 28, outside air is drawn through air holes 26
`formed in outer wrapper 18. The air is drawn through a
`passageway 36 which is formed between outer wrapper
`18 and thermally-insulating tube 20 by spacer rings 38
`and 40. The air exits passageway 36 and enters tube 20
`via air holes 42, and is drawn past heater 14' and
`through the heated flavor-generating medium. The
`mixture of heated air and flavor components is drawn
`through filter 28 for the 'consumer’s use.
`A controlled flavor-generating medium temperature
`(or a consistent heating temperature in a pulse-heated
`system) is required to ensure a substantially consistent
`release/generation of
`flavor
`components. Flavor-
`generating medium 12 typically is maintained at a con-
`-trolled temperature by means of a control system. Con-
`trol systems suitable for use with this invention may be
`either “passive” systems or “active” systems. A passive
`control system is one that uses heating element 14 or
`power source 16 themselves to regulate the temperature
`of flavor-generating medium 12 or the amount of power
`applied to the heating element. An active control sys-
`tem uses an additional components such as an electronic
`control circuit, or requires participation from the con-
`sumer, to consistently heat the flavor-generating me-
`dium.
`
`In a preferred embodiment of the invention, the arti-
`cle utilizes a passive, coupled system to control the
`heating process and to control the amount of flavor
`component generated. The characteristics of the com-
`ponents in the coupled system are selected to maintain
`flavor-generating medium 12 at a controlled tempera-
`‘ ture throughout operation. The critical components of
`the coupled system include flavor-generating medium
`12, heating element 14, and power source 16. This type
`of coupled control system is most effective in articles
`which have a self-contained power source.
`The coupled system works as follows. Power source '
`16 discharges electrical energy to heating element 14.
`Heating element 14 converts the discharged electrical
`energy into heat. The thermal masses and material prop-
`erties of heating element 14 and flavor-generating me-
`dium 12 rapidly absorb the heat and prevent smoking
`article 10 from overheating. More energy is released at
`the beginning of operation, when power source 16 is
`fully charged. After a short period of operation, power
`output from power source 16 is reduced, because the
`power source has discharged most of its potential en-
`
`VMR-Ex. 1011-012
`
`
`
`5
`resistance of power
`ergy and because the internal
`source 16 rises (due to its self-heating properties). The
`discharge characteristics of power source 16 change
`due to the discharge of energy to the heating element,
`and due to losses internal to the power source. Because
`flavor-generating medium 12 and heating element 14
`retain heat generated during the initial high-energy
`discharge of power source 16, the temperature of fla-
`vor-generating medium 12 remains substantially con-
`stant, even as the electrical energy output of power
`source 16 is reduced. When the electrical energy of
`power source 16 is depleted, flavor-generating medium
`12 may be removed and replaced with fresh material,
`and power source 16 may be recharged, prior to reuse.
`A change in any one component of the coupled sys-
`tem affects the performance of the other components.
`Flavor-generating medium 12, heating element 14, and
`power source 16 must be empirically tailored to select
`the desired operating temperature of article 10. For
`example, a heating element having a lower resistance
`and lower mass would allow more current to flow, and
`would allow flavor-generating medium 12 to heat more
`quickly. Also,
`the thermal characteristics of flavor-
`generating medium 12 vary with the size and quantity of
`the pellets forming the flavor-generating medium. In-
`creased surface area, resulting from smaller pellet size,
`permits flavor-generating medium 12 to absorb thermal
`energy at a quicker rate by providing more contact with
`the heating element and adjacent particles.
`The amount of total particulate matter (TPM) re-
`leased from a given flavor-generating medium is pro-
`portional to the time temperature history of the me-
`dium. For example, heating a 100 milligram sample of
`the material at 120° C. typically can "release two milli-
`grams of TPM in a given time period. The same sample,
`heated to 280° C. for the same amount of time, releases
`22 milligrams of TPM. Thus, the delivery of the article
`may be regulated by selecting components of the cou-
`pled system to achieve a predetermined temperature.
`In an equally preferred embodiment, heating element
`14 is a positive temperature coefficient thermistor. A
`thermistor is a temperature-sensitive resistor which
`provides passive temperature control. When the therm-
`istor reaches a predetermined temperature (i.e.,
`the
`so-called “transition temperature” of the thermistor), its
`electrical resistance greatly increases, reducing current
`flow through the thermistor and therefore the heating.
`If the temperature of the thermistor decreases, the elec-
`trical resistance also decreases, causing additional cur-
`rent to flow and heating to increase. The thermistor
`maintains a constant bed temperature by continually
`adjusting the current flow in response to thermistor
`temperature (and flavor-generating medium tempera-
`ture). Positive temperature coefficient thermistors suit-
`able for use in the present invention are commercially
`available, for example, from Murata Erie North Amer-
`ica, 220 Lake Park Drive, Smyrna, Ga. 30080 (thermis-
`tor part No. P'IH420AG l000NO32).
`FIG. 4 is a graph of the temperature characteristic of
`a typical positive temperature coefficient thermistor. By
`selecting the appropriate thermistor, the transition or
`stabilization temperature may be selected to achieve a
`desired flavor strength for the article. FIG. 4 illustrates
`the rapid heating abilities of the thermistor. Because of
`its chemical composition, the positive temperature coef-
`ficient thermistor functions as a self-regulated heating
`device.
`
`5
`
`10
`
`20
`
`25
`
`30
`
`35
`
`40
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`45
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`50
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`55
`
`60
`
`65
`
`5,144,962
`
`6
`There are several advantages to heating the article
`with therrnistors rather than conventional resistance
`heaters. Articles having therrnistors do not require ther-
`mostats or control circuits to prevent overheating, pro-
`vide a controlled surface temperature independent of
`ambient conditions, and provide a stable temperature
`almost independent of the supply voltage. These fea-
`tures make the device an excellent choice for heating
`flavor-generating media in articles because it provides a
`consumer with a relatively consistent delivery of flavor
`from puff to puff.
`FIG. 5 is a graph of the power consumed by the
`thermistor to produce the temperatures shown in FIG.
`4.
`
`Articles of the present invention may utilize active
`control systems to regulate operation. One preferred
`system is a double heater/pulse design, shown in FIG.
`6. A first heating element 14 maintains the temperature
`of flavor-generating medium 12 at a substantially con-
`stant
`temperature, below the temperature to which
`flavor-generating medium 12 must be heated to gener-
`ate the desired aerosol. A second heating element 14' is
`pulsed with electrical energy to raise the temperature of
`the medium above the vaporization temperature to
`produce the desired flavor components.
`Flavor-generating medium 12 is captured within tube
`20, which may be a metal or other thermally conductive
`container. Heating element 14 surrounds and can be in
`thermal contact with tube 20 to heat the contents of the
`
`tube. Heating element 14 preferably heats the air drawn
`through passageway 36 before the air is drawn into tube
`20. Heating element 14’, which typically may be dis-
`posed within flavor-generating medium 12, is pulsed for
`a predetermined period with electrical energy from
`power source 16 to generate/release flavor components
`for each puff.
`The double heater/pulse design of FIG. 6 provides
`two distinct advantages. First, less energy is required
`from power source 16 to provide the same flavor-
`generating capability as a constant temperature system.
`The flavor-generating medium is maintained at a lower
`temperature for most of the operating period. A high
`temperature is not maintained; flavor-generating me-
`dium 12 is pulsed to the higher temperature for short
`periods, which consumes less energy. Second, the fla-
`vor components are generated in the short time period
`immediately prior to, and/or during pufling with only
`nominal amounts of flavor components accumulated
`between puffs. This results in an improved flavor com-
`ponent delivery.
`A more preferred embodiment of article 10 includes
`only a single heating element which contacts flavor-
`~ generating medium 12. The heating element provides
`both the constant, low-level heating between puffs, and
`the high temperature pulse for each puff.
`A second type of active control system, shown in the
`smoking article 44 of FIG. 7, is an electronic control
`circuit 4-6 which regulates power delivered to a. single
`heating element 14. Circuit 46 provides a predictable
`method for applying voltage and current to heating
`element 14, and thus for controlling the temperature of
`flavor-generating medium 12. Control circuit 46 has
`two operating modes for efficient power use: a “low
`power” mode for maintaining flavor-generating me-
`dium 12 at a predetermined low-level
`temperature
`(below the vaporization temperature) between puffs,
`and a “high power” mode for rapidly raising heating
`element 14 to its preferred, higher operating tempera-
`
`VMR-Ex. 1011-013
`
`
`
`7
`ture. Circuit 46 typically provides a fixed lock-out time
`between high power operations to prevent inadvertent
`over-heating of flavor-generating medium 12 by fre-
`quent high power operation.
`Circuit 46 is connected to power source 16 by a dou-
`ble-pole, double-throw switch 48, which is shown in the
`“oft” position in the drawing. When switch 48 is placed
`in the “on” position, the positive terminals of power
`source 16 is connected to the input terminals (pin 1) of
`voltage regulators 56 and 58. Regulators 56 and 58 are 10
`standard, commercially available integrated circuits
`(such as Models 7508 and LM3l7T, available from
`Radio Shack, Division of Tandy Corporation, Fort
`Worth, Tex.). The negative terminal of power source 16
`forms a ground reference for the circuit.
`To operate smoking article 44,
`the consumer sets
`power switch 48 to the “on” position. Article 44 oper-
`ates initially in the high power mode. Flavor-generating
`medium 12 is quickly heated to its preferred, higher
`temperature, enabling the consumer to puff article 44.
`When the time interval for the high power mode elap-
`ses, control circuit 46 enters the low power mode to
`maintain flavor-generating medium 12 at a reduced
`temperature. The consumer is prevented from initiating
`the high power mode for a predetermined lock-out
`period,
`to prevent overheating the smoking article.
`When the lock-out period has elapsed, the consumer
`may re-enter the high power mode by actuating a
`switch 50. The cycle is repeated each time switch 50 is
`actuated. When the consumer has finished,
`the ex-
`pended flavor-generating medium may be replaced in
`preparation for the next use of the device.
`Circuit 46 includes two timing circuits 60 and 62,
`which are based on standard (low power) integrated
`circuit (IC) timers 64 and 66 (such as Model TLC555,
`also commercially available from Radio Shack). Timing
`circuits 60 and 62 control the low power and high
`power modes of operation, respectively. Voltage regu-
`lator 56, with pin 3 connected to ground, regulates the
`voltage to the resistor-capacitor (RC) network that
`determines the duration of the high power lock-out
`period.
`Resistor 68 connects the output and voltage adjust
`pins (pins 2 and 3, respectively) of voltage regulator 58,
`causing regulator 58 to function as a current limiter
`when circuit 46 operates in the low power mode. The
`output of regulator 58 is bypassed during the high
`power mode.
`The regulated output voltage (pin 2) of voltage regu-
`lator 56 is connected to the positive power terminal (pin
`8) of timer 64 and to an RC network. The negative
`power terminal (pin 1) of timer 654 is grounded. The
`RC network includes a variable resistor 70, a fixed resis-
`tor 72, and a capacitor 74. The output of timer 64 (pin 3)
`, is controlled by the RC network and is triggered by a
`negative pulse on pin 2, which in turn, is caused by
`grounding pin 2 through switch 50. The charging time
`is determined by the values of resistors 70 and 72, and
`capacitor 74, which are selected to obtain a charging
`time which typically may be in the range of about five
`to about thirty seconds, and preferably between ten and
`twenty seconds, and most preferably fifteen seconds.
`Switch 50 is connected to the RC network between
`
`resistor 72 and capacitor 74 on one side, and is grounded
`on the other. Switch 50 discharges capacitor 74 when
`actuated, resetting the charging time of circuit 60 to
`zero, and generating an output at pin 3 of timer 64.
`When the voltage on capacitor 74 exceeds two-thirds of
`
`5,144,962
`
`8
`the supply voltage, the high power lock-out period
`elapses, and the consumer may again cause the circuit to
`enter the high power mode (to generate flavor compo-
`nents).
`Pin 2 (regulated output voltage) of regulator 56 con-
`nects to timing circuit 62 through the normally-open
`contacts of relay 76., When the output from pin 3 of
`timer 64 is high, the coil of relay 76 is energized, and the
`relay contact is closed. Power is then supplied to timing
`circuit 62. Timing circuit 62 includes timer 66 and a
`second RC network which includes variable resistor 78,
`fixed resistor 80, and capacitor 82. The charging time of
`the second RC network is determined by the values of
`resistors 78 and 80, and capacitor 82, which are selected
`to obtain a charging time which typically may be in the
`range of about 0.2 to about 4.0 seconds, preferably be-
`tween 0.5 and 2.0 seconds, and most preferably between
`1.2 and 1.6 seconds. This charging time controls the
`duration of the high power mode. The output of timer
`66 (pin 3) is controlled by the second RC network, and
`becomes high when the voltage at pin 2 of timer 66
`drops below one-third of the supply voltage. Pin 7 of
`timer 64 provides a discharge path for capacitor 82, to
`trigger the output at pin 3 of timer 66 and to reset timing
`circuit 62.
`Variable resistors 70 and 78 permit adjustment of the
`charging time for timing circuits 60 and 62, respec-
`tively. In an alternative embodiment, resistors 70 and 72
`and resistors 78 and 80 are replaced with a respective
`one of a single, fixed resistor. If the desired charging
`times are known and fixed, it is advantageous to use a
`single, fixed resistor for each pair, to reduce the size and
`complexity of circuit 46.
`The output of timer 66 (pin 3) is connected to the coil
`of relay 86, and therefore controls the voltage across
`the coil of relay 88. Relay 88 controls whether heating
`element 14 is heating in the low power or high power
`mode, by controlling the voltage across output termi-
`nals 90. Relay 88 switches either the regulated current
`output of voltage regulator 58 (low power mode) or the
`positive voltage of power source 16 (high power mode)
`to output terminal 90. The contact of relay 88 is nor-
`mally switched to terminal a, which is connected to the
`regulated current output (pin 2) of regulator 58. Termi-
`nal b of relay 88 is connected to the positive terminal of
`power source 16, through power switch 48. When relay
`86 is energized, current flows from power source 16 and
`through relay 86, energizing the coil of relay 88. The
`contact of relay 88 then switches to terminal b. LED 54
`connects the common contact of relay 88 with series
`resistor 92 (the resistor’s second terminal is grounded).
`Resistor 92 is selected such that LED 54 is illuminated
`‘ only during the high power mode.
`Changing any component of control circuit 46 will
`affect the performance of the entire circuit, and thus
`affect the operation of article 44. In particular, changing
`the values of the resistors and capacitors which form
`the first and second RC networks of timing circuits 60 ’
`and 62 will alter the charging times of these circuits, and
`thus alter the duration of high power operation and the
`duration of the high power lock-out period. The opti-
`mal duration of each time interval is determined primar-
`ily y the characteristics of flavor-generating medium 12
`and heating element 14. For example, a heating element
`having a lower electrical resistance would allow more
`current to flow, and would allow the flavor-generating
`medium to heat more quickly. This, in turn, might allow
`for a shorter high power operation.
`
`VMR-Ex. 1011-014
`
`
`
`5,144,962
`
`9
`A third type of active control system uses a tempera-
`ture-sensing feedback loop to control the heating cycles
`applied to flavor-generating medium 12. For example,
`temperature-sensing devices such as thermocouples,
`thermistors, and resistive temperature devices (RTDs)
`may be used to sense temperature and regulate the
`power flowing to the heating element to maintain a
`predetermined temperature. An illustrative embodi-
`ment of this control system is shown in FIG. 80.
`Referring now to FIG. 8a, heating element 14 is con-
`nected directly to a voltage supply, and is grounded
`through a normally-closed contact of a single pole,
`double throw relay contact 81. The relay is actuated
`under the control of a switched output set point control-
`ler 83 (Model AD59S, manufactured by Analog De-
`vices, Norwood, Mass.) via pin 9. The controller 83 is
`connected to the voltage supply via pin 11, and is
`grounded via pins 1, 4, 7, and 13. A “K” type thermo-
`couple 85 has an iron and a constantan pin, which are
`connected to pins 1 and 14 of controller 83, respec-
`tively. Controller 83 is connected (via pin 8) to an out-
`put voltage of about 2.5 volt from pin 2 of a voltage
`regulator 87 (Model AD580, manufactured by Analog
`Devices, Norwood, Mass.). Voltage regulator 87 is
`connected to a voltage supply via pin 1, and is grounded
`via pin 3.
`When power is initially switched on, current flows
`through the heater until the predetermined tempera-
`ture, set by the voltage reference (at pin 8), is reached.
`If the voltage reference is 2.5 volts, the set point temper-
`ature is 250° C. (the temperature set point corresponds
`to approximately 100° C. per volt). Once the set point
`temperature is reached, the output of controller 83 is
`equal to the supply voltage, and the relay is energized.
`At this point, the normally-closed relay contact opens,
`causing the current flow through the heater to cease.
`The temperature will then drop below the set point
`temperature, causing the relay to deenergize, closing
`the normally-closed conta