NO317865B1 - Cigarette and heating element for use in an electric smoke system - Google Patents

Description

Field of invention

The present invention generally relates to electric smoking systems, then more particularly cigarettes which are adapted to work together with electric lighters in electric smoking systems, as well as a heating element for use in electric smoking systems.

Background for the invention

Traditional cigarettes impart flavor and aroma to a smoker as a result of combustion in which a mass of combustible material, usually tobacco, remains burned at temperatures often exceeding 800° C during a puff on the cigarette. Heat is drawn through the adjacent tobacco mass by the smoker drawing air in from the mouth end of the cigarette. During this heating, an incomplete acceleration of the combustible material takes place, and various gaseous combustion products and distillates from the tobacco are thereby released. As these gaseous products are sucked through the cigarette, they will cool and condense into an aerosol that gives the taste and smell experiences associated with smoking.

Traditional cigarettes have been attributed various perceived disadvantages. Some of these are the production of so-called sidestream smoke, which is produced by combustion between each puff of the cigarette, and which can be a disadvantage for non-smokers through so-called "passive smoking". As soon as a cigarette is lit it will usually be consumed and then the butt will be discarded. It is of course possible to light an extinguished cigarette again, but this usually does not happen due to various reasons such as loss of taste, smell and aroma.

An alternative to the more traditional cigarettes includes those where the combustible material itself does not release the tobacco aerosol. Such smoking articles include a combustible carbonaceous heating element (the heat source) located at or near one end of the smoking article and a layer of tobacco-filled elements located next to the aforementioned heating element. The heating element is then lit with a match or a cigarette lighter, and when the smoker sucks on the cigarette, the heat developed in the heating element will spread to the layer of the tobacco-filled elements, so that a tobacco aerosol is released in this layer. Although this type of smoking device produces little or no sidestream smoke, it will nevertheless produce different combustion products in the heat source, and once such a heat source is lit, it will not in practice be extinguished and then lit again in the future.

In both the more common cigarettes and the aforementioned carbon-heated devices described above, combustion occurs when they are used. This process naturally gives rise to a number of by-products as the burnt material breaks down or is consumed, and this naturally affects the surrounding atmosphere.

U.S. patent application serial no. 08/380,718 filed Sep. 30, 1995 (PM 1697 Cont) and Serial No. 07/943,504 filed September 11, 1992 (PM1550) together with US Patents 5,093,894, 5,225,498, 5,060,671 and 5,095,921 describe various heating elements and flavoring articles that substantially reduce sidestream smoke while allowing the smoker to selectively stop smoking and then resume smoking again at a later date. However, the cigarette articles described in these patents are not particularly durable and will easily break, break or collapse after a certain period of treatment. In certain cases, these prior art cigarettes can be easily crushed as they have a relatively weak construction and they can also easily break when removed from the cigarette lighter.

The aforementioned US Patent Applications Serial No. 08/380,718 (PM 1967 Cont) and US 5,388,594 describe an electric smoking system which includes an electric cigarette lighter and a new cigarette cooperating with this lighter. A preferred embodiment of this cigarette lighter includes a series of metallic, tube-shaped heating elements which are positioned in such a way that they slidably receive a tobacco portion of the cigarette.

The preferred embodiment of the cigarette in serial no. 08/380,718 (PM 1697 Cont) and also described in EP-A-0,615,411 consists of a tobacco-filled carrier tube, a cigarette paper placed around this, an arrangement of flow-through filters at the mouth end of the carrier tube and a filter plug at the free (distal) end of the carrier tube. The cigarette and the lighter are designed in such a way that when the cigarette is inserted into the lighter and as the individual heating elements are activated for each puff on the cigarette, there will be a localized charring of the cigarette where it is next to the heating elements (such points will be referred to in the following as the "heating element footprint"). As soon as all the heating elements have been activated, these charred points will lie close together and surround a central part of the cigarette carrier.

Depending on the maximum temperatures and the total energies supplied to the heating elements, the charred points will manifest more or less strong discolorations of the cigarette paper. In most embodiments, said charring will eventually cause at least small breaks in the cigarette paper and the underlying support material, and this tends to weaken the cigarette mechanically. In order for the cigarette to be removed from the lighter, the charred points must at least partially pass the heating elements. Under certain unfortunate circumstances, such as when the cigarette is wet or has been treated or otherwise twisted, the cigarette will easily break or leave pieces inside the lighter when the cigarette is removed. Such pieces that remain in the lighter itself will of course affect the use of the lighter and/or lead to a bad taste and smoke from the next cigarette. If the cigarette breaks in two when removed from the lighter, the smoker will not only be frustrated by the failure of the cigarette product, but also by the fact that he or she has to clean the clogged lighter before he or she can again enjoy another cigarette.

A preferred embodiment of the cigarette described in US serial no.

08/380,718, EP-A-0,615,411 and patent no. 5,388,594 is essentially a hollow tube between the filter plugs at the mouth end of the cigarette and the plug at the distal end. It is assumed that this construction provides a better supply to the smoker by providing sufficient space where said aerosol can develop in the carrier tube with minimal contact and condensation of the aerosol on the nearby surfaces.

Several devices have been proposed which should be able to significantly reduce unwanted sidestream smoke while at the same time enabling the smoker to stop smoking, for example for a desired period, after which smoking can be resumed. Thus, for example, US patents No. 5,093,894; 5,225,498; 5,060,671 and 5,095,921 various heating elements and flavor developing systems. EP-A-0,615,411 and US patent no. 5,388,594 describe an electric smoking system where different types of heating elements are activated when different control circuits are exposed to a puff on the cigarette. The heating elements are preferably relatively thin hose-like structures which transfer sufficient heat to the cigarette, which is of relatively light weight.

Although these heating devices and heating elements avoid the aforementioned problems and achieve the stated purposes, many of these designs are subject to mechanical weakening and possible failure due to the stresses applied when the cylindrical tobacco medium is inserted or removed from the lighter other than when desired to adjust or play with the inserted cigarette.

Furthermore, unwanted electrical short circuits can easily occur if the shape of a heating element is changed, for example by adjusting or playing with the inserted cigarette.

The electric smoking systems also use electrically resistive heating elements which have made it necessary to use relatively complex electrical circuits which can easily be disturbed or destroyed when inserting or removing the cigarette.

When we placed cut tobacco in the hollow structure found in the cigarette described in EP-A-0,615,411, it was discovered that such a cigarette, when completely filled with cut tobacco, would be able to perform quite satisfactorily in an electric lighter in the first dragons. After that, its supply of smoke and aroma seems to decrease. The same phenomenon tends to occur when more traditional cigarettes are smoked in an electric lighter, such as the type described in EP-A-0,615,411.

When the hollow cigarette structures described in the preferred embodiments of EP-A-0,615,411 were laid unfilled, they tended to collapse when subjected to rough handling.

The present invention in its aspects defined by the attached independent claims.

A cigarette incorporating aspects of the present invention has the advantage of containing cut tobacco that consistently acts like a cigarette when smoked as part of an electric smoking system.

A cigarette that includes aspects according to the present invention has the advantage that it contains cut tobacco, is adapted to work together with an electric lighter and at the same time provides satisfactory levels with regard to taste and delivery.

A cigarette that includes aspects of the present invention also has the advantage that it includes cut tobacco while providing a consistent supply of flavor qualities from puff to puff.

Cigarettes incorporating aspects of the present invention can be easily manufactured and packaged in attractive packages.

Cigarettes incorporating aspects of the present invention are physically robust and will minimize condensation and/or filtration of the aerosol within the cigarette and/or lighter. The cigarettes are also resistant to breakage when the cigarette is removed from the lighter.

Cigarettes incorporating aspects of the present invention are suitable for use with a lighter having an electric smoking system and are far less susceptible to collapse or breakage under rough handling by the user.

Cigarettes incorporating aspects of the present invention are suitable for use with a lighter in an electric smoking system that is not subject to collapse or breakage during the manufacture or packaging of the cigarette.

Cigarettes incorporating aspects of the present invention that are operable with an electric lighter can be manufactured by cost-effective methods and high production rates.

Heating elements comprising in aspects of the present invention can develop smoke from tobacco-containing medium without concern for combustion, can reduce the formation of unwanted side stream smoke and can enable the smoker to stop smoking and resume this besides improving the aerosol development inside the smoking system.

A heating element structure included in the present invention can provide a desired number of puffs and can be easily modified so that the number and duration of the puffs used during smoking are changed without sacrificing the tobacco's subjective qualities.

A heating element according to the present invention can be mechanically adapted so that one can easily insert and remove a cigarette.

An electric resistance heating element which is part of the present invention can have very simple connections to a connected power source.

A heating element included in the present invention can be mechanically stable during several heating cycles.

Embodiments of the present invention will minimize the variation of an interphase between the heating element and the cigarette to avoid changes in heat transfer.

A heating element according to the present invention is very simple and economical to produce.

A preferred embodiment according to the present invention provides a smoking system for supplying a smoker with flavorful tobacco quality. The system includes a cigarette and an electrically powered ignition mechanism, the latter of which includes a number of electric heating elements and where each of these is adapted either individually or together so that a predetermined amount of tobacco aerosol is released from the cigarette when it or they are activated. The cigarette consists of a tubular tobacco tissue, the largest part of which is filled with a column of tobacco, preferably in the form of cut tobacco, and while the other part of the tubular tobacco tissue is not filled or is hollow so that a cavity is defined inside the tobacco column.

More particularly, the aforementioned cigarette preferably consists of a tobacco stick formed by means of a tubular tobacco web and a plug of tobacco placed inside said tubular tobacco stick. The tobacco stick is adapted so that it can slide into contact with an electric heating device so that the heating elements are placed along the tobacco stick in positions between the free end and the opposite end of the tobacco stick. Preferably, the plug or column of tobacco extends from the free end of the tobacco stick to a position at a certain distance from the opposite end of the tobacco stick, so that a cavity (or hollow part) is defined near the opposite end.

The relative dimensions of the cigarette <p>g the heating device in the lighter mechanism are determined in such a way that when the cigarette is inserted into the lighter, each heating element is placed along the tobacco stick at predetermined positions along it, and preferably so that there is a longitudinal contact between the heating element and the cigarette (hereafter "the footprint of the heating element"), lies above at least part of the aforementioned cavity and at least part of the tobacco plug. With the help of this arrangement, you get a continuous and satisfactory supply when the tobacco is smoked electrically, and you get a reduction in the condensation of tobacco aerosol at or around the heating elements.

1 an alternative arrangement is the relative dimensions of the cigarette and the heating elements in the lighter mechanism so that when the cigarette is inserted into the lighter, each heating element will be positioned along the tobacco rod so that at least some, if not all, of the heating element footprints are only adjacent to the filled part of the tobacco stick (over the tobacco plug). With such a configuration, the cavity can be used to facilitate aerosol formation and to cool the smoke.

It is preferred that a cigarette paper is placed around the tubular tobacco tissue so that the look and feel of a more traditional cigarette is provided when this is handled by the smoker.

The tobacco fabric should preferably consist of a non-woven tobacco fabric and a layer of tobacco material placed at least along one side of said tobacco fabric.

The cigarette also preferably includes a filter at the aforementioned opposite end of the tobacco stick, which includes a flow-through filter (also in the tobacco industry called a "whistle plug"), a nozzle filter plug and paper located around the plugs on the tobacco stick.

When a cigarette using the present invention is inserted into a lighter with an electric smoking system, the cigarette will collide with a stop device that is placed inside the heating elements in the lighter (or corresponding registration), so that the electric heating elements in the lighter that are located next to the cigarette will generally be in the same place for each cigarette. When a puff is started, at least one of the heating elements in the lighter will be activated to heat the cigarette at the aforementioned positions along the tobacco stick. As the draw develops, the tobacco stick will be heated and aerosol will be propelled by the tobacco tissue and filler. Where the footprint of the heating element lies above the cavity in the tobacco stick, the tobacco aerosol will immediately be released into the cavity defined by the unfilled portion of the tobacco stick and will then be drawn out of the cigarette. The tobacco tissue will provide most of this portion of the total aerosol delivered by the cigarette, and it is assumed that the immediate proximity favorably affects the type and degree of the smoker's puff or drag on the cigarette. Due to the greater amount of tobacco in the filled portion of the tobacco stick, there will be a slight delay in aerosol release where the footprint of the heating element lies above the filled portion of the stick. The aerosol that is driven out of the filled part of the tobacco stick contributes to a further dominant taste and character of the emitted smoke.

Another aspect of the present invention relates to the ability to adjust the supply from a cigarette in an electric smoking system, where the proportional degree of overlap between filled and unfilled portions of the tobacco stick of the heating element footprint provides the desired adjustments that can be made from one brand of cigarette to a other, or between product variants within the same brand.

Another aspect of the present invention relates to a method for improving the level and uniformity with regard to the supply of aerosol from a cigarette within an electric heating device, and where the cigarette has a free end and an opposite end. This method includes steps of having a heating element footprint over both a tobacco-filled portion of the cigarette near the free end and an unfilled portion of the cigarette at the opposite end, while resistively heating the heating element itself and sucking on the cigarette through the opposite end.

Another aspect of the present invention relates to an insert that contains a cigarette that is operative together with an electric lighter, and where the cigarette includes a tobacco stick that has a free-flow filter and an insert-free part near the free-flow filter so that a uniform aerosol production is obtained.

Another aspect of the present invention relates to a reinforced tubular tobacco fabric with flax or wood cellulose fiber attached to its base fabric so that additional strength is obtained. In an alternative, cellulose fibers from the nerve of the tobacco leaves can be included in the composition of the base tissue itself as a reinforcing agent.

The robustness of the cigarette has been improved by adding cut tobacco within the tubular tobacco tissue so that you get a cigarette that can better withstand treatment, and this includes treatment by cigarette manufacturing machines and by the consumer.

A heating element included in the present invention preferably consists of a supporting center and a number of electric blades heated by means of electric

resistance and which together define a sleeve into which a cigarette can be inserted. Each heating element blade includes a first heating element foot having a first end and a second end extending from the first end of the supporting sleeve, and a second heating element foot having a first end and a second end and a connecting section connecting the second end of the first foot and the first end of the other foot. The other end of the second foot is extended towards the supporting sleeve and is electrically isolated from this. An electrical resistance circuit is formed so that the electrical resistance element can be heated, which in turn heats the inserted cigarette. The first and second legs are separated by a space to allow air to enter and facilitate the development of flavorings from the heated cigarette when sucked on by a smoker.

Embodiments of the invention will now be described by means of examples and with references to the attached drawings, where: Figures 1 and 2 are perspective sketches of an electronic smoking system in accordance with a preferred embodiment of the present invention; Figure 3 is a partially cutaway perspective view of a cigarette placed inside the heating element of the smoking system shown in Figure 1; Figure 4A is a longitudinal section through a cigarette constructed in accordance with the preferred embodiment of the present invention; Figure 4B is a detailed perspective view of the cigarette shown in Figure 4 with certain components of the cigarette partially cut away; Figures 5A and 5B are process diagrams of a preferred method of manufacturing coils of tobacco tissue for the cigarettes shown in Figures 4A and 4B, wherein Figure 5A shows the steps of converting the tobacco raw material into a flake of tobacco tissue, while Figure 5B shows the steps used to convert the tobacco sheet or flake into coils of tobacco tissue; Figure 6A is a cross-section of a cigarette constructed in accordance with a substantially hollow embodiment of the present invention; Figure 6B is a graph of aerosol production versus time during each puff developed by a cigarette constructed in accordance with a substantially hollow embodiment of the present invention as shown in Figure 6A; Figure 6C shows the smoke measuring device used to obtain the data shown in Figures 6B, 7B and 8; Figure 7A is a cross-sectional view of a cigarette constructed in accordance with a fully filled embodiment of the present invention; Figure 7B is a graphical representation of aerosol production versus time during each puff developed by. a cigarette constructed in accordance with the fully filled embodiment shown in Figure 7A; Figure 8 is a graphical comparison of the aerosol volume for each sequential puff delivered by each cigarette of those described with reference to Figures 4A, 6A and 7A; Figure 9 is a graphical representation of the relationship between the supply of total particulate matter (TPM) and the amount of overlap between the heating element and the filled portion of a partially filled cigarette made in accordance with the preferred embodiment (Figure 4A) of the present invention; Figure 10 is a cross-sectional view of a cigarette constructed in accordance with another preferred embodiment of the present invention; Figure 11 is a cross-section of a cigarette constructed in accordance with a third preferred embodiment of the present invention; Figure 12 is a longitudinal section of a heating element arrangement where a further aspect of the present invention is applied; Figure 13 is a longitudinal section of a heating element device where another aspect of the present invention is used; Figure 14 is a longitudinal section of a heating element arrangement where another aspect of the present invention is used and where an electrically insulating coating is used; Figure 15 is a longitudinal section of a heating element assembly using an aspect of the present invention where an electrically insulating coating forms a sleeve; Figure 16 is a longitudinal section of a heating element assembly using an aspect of the present invention where one has snake-shaped heating element blade feet: Figure 17A is a cross section of a heating element blade having a flat underside that faces the inserted cigarette; Figure 17B is a front cross-section of a heating element blade having an angled underside facing the inserted cigarette; Figure 17C is a front cross-sectional view of a heating element blade having a curved underside down toward an inserted cigarette; Figure 18 is a top view of a schematic arrangement of heating element blades in a flat state prior to coiling; Figure 19 is a top view of a non-symmetrical arrangement of heating element blades in a flat state before coiling; Figure 20 is a cross-section of an electric smoking system where the present invention is used and which shows an alternative heating element design; Figure 21 is a longitudinal section of the receiver chamber in a flavor cartridge in the electric smoking system shown in Figure 20 and taken along line A-A in Figure 20; Figure 22 is a radial cross section showing another alternative heating element design; Figure 23 is a longitudinal section of the receiver chamber in a flavor cartridge in the electric smoking system shown in Figure 22 and taken along line B-B in Figure 22.

Detailed description of the preferred designs.

Referring to Figures 1 and 2, a preferred embodiment of the present invention provides a smoking system 21 which includes a partially filled cigarette 23 and a lighter 25 which can be reused. The cigarette 23 is designed so that it can be inserted and removed from the receiver 27 in the front part 29 of the lighter 25. As soon as the cigarette 23 is inserted, the smoking system 21 will be used in the same way as a normal traditional cigarette, but without lighting or glowing cigarette 23. Cigarette 23 can be discarded after one or more puffs or puff cycles. Preferably, each cigarette 23 provides two and a number of 8 puffs (puff cycles) or more per smoking, but it is however a matter of design so that one can adjust this number of available puffs to a larger or smaller number.

The igniter 25 includes a housing 31 with front and rear parts 33 and 35. One or more batteries 35a are removably located inside the rear housing part 35 and supply energy to a series of electrical resistance heating elements 37 which are located inside the front part 33 near the receiver part 27. A control circuit 41 in the front part 33 provides electrical communication between the batteries 35a and the heating elements 37. Preferably, the back part 35 is adapted so that it can be easily opened and closed, e.g. with screws or otherwise, where but can easily replace the batteries. If it is desired, one can provide some form of electrical contact for charging the batteries with normal current or the like.

It is preferred that the front skin part 33 is united with the rear housing part 35 so that it can be removed, for example with a so-called dovetail joint or in some other way. The housing 31 is preferably made of a hard heat-resistant material. Preferred materials include metals or more preferably polymeric materials. It is preferred that the housing 31 has total dimensions of approximately 10.7 cm x 3.8 cm x 1.5 cm, so that it easily fits into the hand of a smoker.

The batteries 35a are designed in such a way that they provide sufficient power to the heating elements 35 so that they function as intended and preferably consist of a replaceable and rechargeable type. Alternative power sources are suitable, for example in the form of capacitors. In a preferred embodiment, the power source consists of 4 nickel-cadmium battery cells connected in series with a total no-charge voltage of approximately 4.8 to 5.6 volts. The characteristics of the required power source are, however, selected with regard to the other components of the smoking system 21, in particular the characteristics of the heating elements 37. US Patent No. 5,144,962 (PM 1345), which is incorporated herein by reference, describes several types of power sources that can be used in in connection with the smoking system described in the present invention, for example, rechargeable battery sources and power arrangements which include a capacitor which can be charged by means of a battery.

As shown in Figure 3, the front part 33 of the lighter 25 carries an essentially cylindrical heating element assembly 39 which slidingly receives the cigarette 23. The heating element assembly 39 houses the heating elements 37 and is adapted so that they carry an inserted cigarette 23 in a fixed relationship to the heating elements 37, and is so that these are placed along the length of the cigarette and in approximately the same positions for each cigarette inserted into the system. Where the heating element 37 rests against (or is in thermal contact with) a fully inserted cigarette 23 will be referred to below as the footprint of the heating element.

In order to ensure a consistent placement of the heating elements 37 in relation to each cigarette 23 from cigarette to cigarette, the heating element assembly 39 is equipped with a stopper 182 which the cigarette encounters during its placement in the lighter 25. Other suitable arrangements for registering cigarette 23 in relation to the igniter 25 can of course also be used.

Front housing part 33 of the igniter 25 also includes an electrical control circuit 41 which delivers a predetermined amount of energy from power source 35a to the heating elements 37. In the preferred embodiment, heating element assembly 39 includes 8 heating elements placed in a circle with a certain distance, and which are centrally aligned with the receiver part 27 and which has a snake shape. Details regarding the heating elements 37 are illustrated and described in the pending US application no. 07/943,504 (PM

1550), which has not been decided and the specified US patent no. 5,388,594 (PM 1697) which is incorporated herein in its entirety as references. Other heating element assemblies 37 that may be used in the igniter 25 include those described in pending US Patent Application Serial No. filed January 6, 1995 (Attorney Docket No. PM 1729B CIP II) and pending US Application No. 08/ 291,690 filed August 16, 1994 (Attorney Docket No. PM 1719) all of which are incorporated by reference in their entirety, and which are indicated in the last part of this description with respect to figures 13 to 23. It is preferred that the heating elements 37 are individually supplied energy from the power source 35a under the control of the circuit 41, so that the cigarette 23 is preferably heated 8 times in places located along the periphery of the cigarette 23. The heating makes it possible to have 8 puffs from the cigarette 23 as usually happens during the smoking of a more common

cigarette. It is preferred that more than one heating element is heated at the same time for one or more of the drafts mentioned.

Another preferred arrangement with respect to the heating element is disclosed in the pending US Patent Application Serial No. 08/224,848 filed Apr. 8, 1994 (PM 1729B) which is hereby incorporated by reference in its entirety.

With reference to Figure 2, the circuit 41 is preferably activated by a draft-activated sensor 45 which is sensitive either to changes in pressure or changes in the amount of air flow that occurs when a smoker begins a puff on the cigarette 23. The draft-activated sensor 45 is preferably located inside the front part 33 of the lighter 45 and is in communication with a space within the heating element assembly 39 near the cigarette 23 through a channel passing through the bottom of the heating assembly 39 and, if desired, a draft-sensitive tube (not shown). A draft-activated sensor 45 which is intended for use in smoking system 21 is described in US patent 5,060,671 (PM 1337) which is incorporated herein by reference. Drag sensor 45 is preferably a model 163PC01D35 silicon sensor manufactured by the MikroSwitch division of Honeywell, Inc., Freeport, Illinois. Current-sensitive devices, for example of the type that use heating wire anemometry principles, can also be used to good effect to activate one or more of the heating elements 37 when a change in the air flow is detected. As soon as the sensor 45 is activated, the control circuit 41 will direct an electric current to one of the heating elements 37.

An indicator 51 is provided in a position on the outside of the lighter 25, preferably in the front part 33, which indicates that the number of puffs remaining in a smoking of a cigarette 23. The indicators 51 preferably include a seven-segment liquid crystal display. In a preferred embodiment, indicator 51 shows the number "8" when the cigarette detector 53 detects the presence of a cigarette in the heating element assembly 39. The detector 53 is preferably a light sensor at the bottom of the heating element assembly 39 which detects when a light beam is reflected by an inserted cigarette 23. the cigarette detector 53 give a signal to the circuit 41 which in turn gives a signal to the indicator 51. The display with the number "8" on the indicator 51 indicates that 8 puffs have been provided for each cigarette 23 that is available, that is, none of the heating elements 37 has been activated to heat the cigarette 23. After the cigarette 23 is finished smoking, the indicator screen will show the number "0". When the cigarette 23 is taken out of the lighter 25, the cigarette detector 53 will no longer detect the presence of a cigarette 23, after which the indicator 51 is switched off. The cigarette detector 53 is modulated in such a way that it does not constantly emit a light beam, which would otherwise create too strong a load on the power source 35a. A preferred cigarette detector 53 for use in smoking system 21 is a type OPR5005 light sensor manufactured by OPTEX Technology, Inc., 1215 West Crosby Road, Carcollton, Texas 75006, USA.

As an alternative to displaying the number of puffs remaining on the cigarette, the detector display can instead be arranged to indicate whether the system is active or inactive ("on" or "off").

As one of several possible alternatives to using the above cigarette detector 53, a mechanical switch (not shown) can be provided to detect the presence or absence of a cigarette 23 and a power button (not shown) can be provided to activate the circuit 41 when a new cigarette is inserted into the lighter 25, causing the indicator 51 to show the number "8" etc. Power sources, circuits, draft-activated sensors and indicators that can be used in smoking system 21 according to the present invention are described in US patent 05,060,671 (PM 1337) and not -settled US patent application Series No. 07/943,504 (PM 1550), both incorporated herein by reference.

In Figures 4A and 4B, the cigarette 23 is constructed in accordance with a preferred embodiment of the present invention, and includes a tobacco stick 60 and a filter tip 62 which are connected by means of the tip paper 64.

The partially filled cigarette 23 preferably has a constant diameter along its entire length and is similar to more traditional cigarettes, and preferably has a diameter between 7.5 and 8.5 mm, so that the smoking system 21 gives the smoker a well-known "mouth feel". In the preferred embodiment, the cigarette 23 is 62 mm long, which facilitates the use of conventional packaging machines for packaging the cigarettes 23. The combined length of the nozzle filter 104 and the free-flow filter 102 is preferably 30 mm. The tip paper should preferably be approx. 6 mm above the tobacco stick 60. The total on the tobacco stick 62 is preferably 32 mm. You can use other quantity ratios, lengths and diameters than those indicated for the preferred embodiment.

The tobacco stick 60 giving the cigarette 23 preferably includes tobacco tissue 66 which is

folded or folded into a cylindrical shape.

A cover 71 lies intimately around the tobacco tissue 66 and is held together along a longitudinal seam which is of the same construction as a regular cigarette. The cover 71 holds the tobacco web 66 in a folded state around a free-flow filter 74 and the tobacco plug 80.

It is preferred that the cigarette tissue paper 71 is in intimate contact with the tobacco tissue 66 so that an external appearance and feel of the same type as a normal cigarette is obtained. It has been found that a better-tasting smoke is obtained when the covering paper 71 is of a standard type of cigarette paper, preferably a linen paper with approx. 20 - 50 CORESTA (defined as the amount of air measured in cubic centimeters that passes one square centimeter of the material, for example a sheet of paper, in one minute at a pressure drop of 1.0 kilopascal), more preferably from 30 - 45 CORESTA, and a basis weight of approximately 23 - 35 grams per m<2>, more preferably 23 - 30 grams per m<2> and a filter filling (preferably calcium carbonate) of from 23 - 33 weight percent, more preferably 28 - 33 weight percent.

The covering paper 71 preferably contains little or no citrate or other glow-modifying compounds, and where preferred levels with respect to citrate vary from 0 to approx. 2.6% by weight of the coating paper's 71, preferably less than 1%.

The tobacco web 66 preferably includes a base web 68 and a layer of tobacco flavor materials 70 placed along the inner side of the base web 68.1 the tip end 72 of the tobacco stick 60, the tobacco web 66 together with the cover 71 is placed around the tubular free flow filter plug 74. The latter provides a structural definition and supports the tip -end 72 and the tobacco stick 60 and enables aerosol to be sucked in from the inner part of the tobacco stick 60 with a minimum drop in pressure. The free-flow filter 74 also acts as a flow restriction at the tip end 72 of the tobacco stick 60, and it is assumed that this helps to form an aerosol when sucking on the cigarette 23. The free-flow filter is preferably at least 7 mm long to facilitate machining and is preferably tubular, although you can also use other shapes and types of low-power filters, this includes cylindrical filter plugs.

At the free end 78 of the tobacco rod 60, the tobacco web 66 together with the covering paper 71 is placed around a cylindrical tobacco plug 80. The latter is preferably constructed separately from the tobacco web 66 and consists of a relatively short column of cut tobacco which is folded together and held in place by a plug cover 84.

It is preferred that the tobacco plug 80 is constructed by means of a conventional cigarette machine where cut tobacco (preferably mixed) is air-formed into a continuous stick of tobacco on a conveyor belt and continuously enclosed within a band of the plug cover 84 which is then glued together along a longitudinal seam and is then heat sealed. 1 in accordance with the preferred embodiment of the present invention, the plug cover 84 is preferably made from a cellulosic tissue with little or no filler, glue or glow additive (each at levels below 5 percent by weight) and preferably with little or no glue or surface treatment. It is preferred that the tobacco plug cover 84 has a low basis weight, i.e. below 15 g/m and most preferably approx. 13 g/m . The tobacco plug cover 84 preferably has a high permeability in the range from approx. 20,000 to 35,000 CORESTA, and more preferably in the range from 25,000 to 35,000 CORESTA and is preferably constructed of a soft wood fiber pulp, abaca-type cellulose or other long-fiber pulp. Such papers are available from paper mill Schoeller and Hoescht GMBH, Postfach 1155, D-76584, Gernsback in Germany, while another paper suitable for use in the plug cover 84 is paper TW 2000 from DeMauduit of Euimperle in France with the addition of carboxymethylcellulose in an amount of about 2.5% by weight.

The tobacco stick making machine is set so that it gives a density on the tobacco stick of approx. 0.17 - 0.30 g/cm<2>, more preferably in the range from at least 0.20 - 0.30 g/cm2 and most preferably between 0.24 - 0.28 g/cm<2>. The elevated densities are preferred to avoid loose ends at the free end 78 of the tobacco rod 60. However, it is understood that lower densities will cause the tobacco column 82 to contribute a greater amount of aerosol and flavor to the smoke. One must therefore try to achieve a balance between aerosol supply (which favors low density on the rod in the tobacco column 82) and this avoiding loose ends (which favors relatively high rod densities).

The tobacco column 84 preferably consists of a cut tobacco mixture of the mixture that is common in the cigarette industry, and this includes mixtures that include light, burley and oriental tobacco types together with possibly reconstituted tobacco and other mixture components of the type used in cigarettes. In the preferred embodiment, however, the filler in the tobacco column 84 consists of a mixture of light, burley and oriental tobacco types in proportions of approx. 45:30:25 for the US market, without the addition of reconstituted tobacco types or other cut flavorings. Alternatively, a so-called expanded tobacco component should be used in the mixture to adjust stick density and flavourings.

A continuous tobacco stick produced as described above can then be cut in accordance with a predetermined plug length for the tobacco plug 80. This length is preferably approx. 7mm to facilitate machining. However, the length can vary from approx. 7-25 mm depending on how the cigarette is to be designed, which will be apparent from the following description with special reference to Figures 4A and 4B.

The length 86 of the tobacco plug 80 should preferably be such, in relation to the total length 88 of the tobacco stick 60, that a cavity is defined along the tobacco stick 60 between the free-flow filter 74 and the tobacco plug 80. The cavity 90 is thus an unfilled part of the tobacco stick 60 and stands in immediate flow contact with the tip

62 through the free-flow filter 74 in the tobacco stick 60.

As shown in Figure 4A, the length 86 of the tobacco rod 80 and the relative placement along the tobacco rod 60 are selected to be in a certain relationship to the heating elements 37. When a cigarette is suitably positioned against the stopper 182 in the heating element assembly 39, a portion 92 of each heating element 37 come into contact with the tobacco stick 60 along a certain area thereof. This contact area is, as previously mentioned, designated the heating element footprint 94. The heating element footprint 94 (shown by a double arrow in Figure 4A) is not part of the cigarette structure itself, but instead represents an area where the tobacco stick 60 and the heating elements 37 can be expected to reach suitable temperatures during the smoking of the cigarette 23. Because the heating elements 37 are located at a fixed distance 96 from the stopper 82 in the heating assembly 39, the footprint 94 of the heating elements will be constantly located along the tobacco stick 60 at the same predetermined distance 96 from the free end 78 of the tobacco stick 60 for each cigarette 23 which is fed into the igniter 25.

It is preferred that the length of the tobacco plug 80, the length of the heating element's footprint 94 and the distance between the latter and the stopper 182 are chosen so that the heating element's footprint 94 goes past the tobacco plug 80 and lies above part of the cavity 90 by a distance 98. This distance 98 where the heating element's footprint 94 lies above the cavity 90 (the unfilled part of the tobacco stick 60) is also termed the "heating element-cavity overlap" 98. The distance where the remaining part of the heating element footprint 98 lies above the tobacco plug 80 will similarly be termed the "heating element-filling overlap" 99.

The tip 68 is preferably a free-flow filter 102 placed near the tobacco stick 60 and a nozzle filter plug 104 at the distal end of the tip 62 from the tobacco stick 60. It is preferred that the free-flow filter 102 is tubular and lets air through through very little pressure drop. However, one can also use other filters of low power of standard configuration. The inner diameter of the free-flow filter 86 is preferably at or near between 2-6 mm and is preferably larger than the corresponding diameter of the free-flow filter 74 in the tobacco stick 60.

The nozzle filter plug 104 closes the free end of the tip 62 to give a better appearance, and if desired, to provide some filtration, although it is preferred that the nozzle filter plug 104 consists of a filter with a low effect, preferably with from 15 - 25% effect.

The free-flow filter 102 and nozzle filter plug 104 are preferably united as a single plug. 110 with a plug cover 112. The latter is preferably porous and has a low weight and is of the type used in standard cigarette manufactures. The assembled plug 110 is attached to the tobacco stick 60 by means of the tip paper 64, the specifications of which are standard of a type commonly known in the cigarette industry. This tip paper 64 can either be cork-coloured, white or any other color according to preference.

In a cigarette 23 produced in accordance with the present embodiment of the invention preferably has a total length of approx. 62 mm, of which 30 mm is made up of the combined plug 110 and plug 62. Accordingly, the tobacco stick 60 is 32 mm long. It is preferred that the free-flow filter 74 in the tobacco stick 60 is at least 7 mm long and that the cavity between the free-flow filter 74 and the tobacco plug 80 is preferably at least 7 mm long. In the preferred embodiment, the heating element footprint 94 is approximately 12 mm long and positioned so that there is a 3 mm heating element - cavity overlap 98. which provides a 9 mm heating element footprint 94 that overlies the tobacco plug 80.

It is understood that the length of the cavity 91 and the length of the tobacco plug 80 can be adjusted to facilitate manufacture and more importantly to adjust the cigarette's smoking characteristics, and this includes adjustments with respect to taste, suction and aerosol delivery. The length of cavity 91 and the amount of overlap between heating element and filler (and overlap between cavity and heating element) can also be manipulated so as to adjust how quickly you get a reaction from the cigarette, to give better consistency with regard to delivery (on drag-to -drag base as well as between cigarettes) and -to regulate or control the condensation of aerosol at or around the heating elements.

In the preferred embodiment, the cavity 91 (the unfilled part of the tobacco stick 60) is approx. 7 mm long to ensure adequate clearance between the heating element footprint94

and the free-flow filter 74. In this way, an edge is obtained so that the heating element's footprint 94 does not heat the free-flow filter 74 during smoking. Other lengths are of course suitable if this is possible within the manufacturing mechanics, and the cavity 92 can be designed as short as approx. 4 mm or less or on the other hand, can

also be longer than 7 mm in order to have an extended filter-free part in the tobacco stick 60. The preferred ranges of variation with regard to lengths, shape, the unfilled parts (cavity 91) are from approx. 4 - 18 mm, more preferred is from 5 - 12 mm.

The base fabric 68 physically separates the heating elements 37 from the tobacco flavor material, transfers heat developed by means of the heating elements 37 to the flavor material 70 and maintains the physical consistency of the tobacco stick during processing, insertion of the lighter 25 and removal of the cigarette residue after smoking.

In the following description, certain percentage levels and/or relative weights are indicated for the various components that make up the tobacco tissue 66. If nothing else is indicated or apparent from the description, then all weight percentages are on a dry weight basis, which essentially means that the stated percentages and/ or relative weights are adjusted for the moisture content which is not included.

The method for producing the tobacco tissue 66 is preferably without adding carbon fibres, which will be described in the following paragraphs. After the cigarette has been manufactured, the base fabric 68 itself will have a total base weight of approx. 35 - 45 g/m<2>, more preferably about 40 g/m<2>. At a weight of 40 g/m<2>, the base fabric 68 will preferably consist of 28 g/m2 of tobacco fiber and approx. 12 g/m<2> of cellulose fiber, for example from wood pulp or flax. The cellulose fibers will serve as a reinforcing agent in the composition or manufacture of the base tissue 68. It is preferred to minimize the amount of cellulose fiber in the base tissue for various reasons (to avoid establishing a paper flavor in the cigarette flavor itself). Typically, the ratio of tobacco fiber to cellulose fiber in the base fabric 68 on a dry weight basis will be approx. 2:1 to 4:1. The preferred cellulose material is an unbleached kraft hardwood cellulose, although most wood pulps and flax pulps can be used.

An alternative reinforcing agent for the base fabric 68 is a cellulose fiber made from tobacco stalks.

Although it is not preferred, alginate can be placed on one side of the base tissue 68 in an amount of about 1 g/m<2.> If alginate is applied, it is preferred that this is only placed on one side of the base tissue 68 and the opposite side of the where the tobacco material 70 is located.

The tobacco material 70 is preferably applied to the base fabric in a dry weight that is at least 2 times and more preferably 3-4 times the weight of the base fabric 68. In a preferred embodiment, the tobacco material has a base weight of approx. 130 g/m2 so that the total weight of the tobacco web 66 is approx. 170 g/m . On a dry weight basis, the tobacco material 70 will consist of some ground tobacco and extracted solids in a ratio that varies approx. 3.5 to 1 (3.5:1) to 5 to 1 (5:1) per weight, although this ratio can be varied within a range from approx. 3:1 to 9:1.1 the preferred embodiment is the ratio approx. 4:1.

Glycerin is often added to the tobacco material 70 as a wetting agent and as an aerosol precursor in amounts from 10-14%, preferably approx. 12% based on the dry weight of the tobacco material 70, but this level can also be varied from approx. 5 to up to 20% or more based on the dry weight of the tobacco material 70. When the glycerin content is reduced to only between 5 and 7% based on the dry weight of the composition, the tobacco web 66 will become somewhat stiffer and more resistant to collapse or collapse when it is later rolled into a tube shape .

Pectin can also be added to the tobacco material 70 in a weight percentage varying from 0.5 - 2%, preferably 1.4%. Pectin is added as a coating agent. In its absence, the tobacco material 70 will tend to penetrate the base fabric 68 too much during the coating operation, giving the coated side of the tobacco fabric 66 a somewhat gritty surface texture. Too much pectin inhibits penetration and weakens the bond between the tobacco material 70 and the base tissue 68. At an amount of approx. 1%, the pectin will promote suitable penetration and bonding between the layers so that the base tissue 68 can withstand the stresses that occur during automatic cigarette manufacturing.

It is most preferred that the tobacco material 70 and the base fabric 68 include from approx. 16-20% on a dry weight basis of extracted solid tobacco substances, 66-71% on a dry weight basis of ground tobacco articles, 8 - 14% glycerine and about 1.4% pectin. For the market in the USA, the ground tobacco that is incorporated into the tobacco material 70 will preferably be a mixture of light, burley and oriental tobacco types of which at least half of the mixture is light tobacco types, about 1/3 is Burley while the rest is oriental. The composition and relative amounts of the mixture's components can be advantageously adjusted to meet consumer preferences both in the United States and other markets.

Figures 5A and 5B show the preferred method of producing a stock of tobacco tissue 66 in a form suitable for the automatic manufacture of the cigarettes 23, which consists of a first series of steps 120 (shown in Figure 5A) to convert the tobacco raw material , preferably stripped or cleaned tobacco, into a continuous sheet of tobacco tissue 66 and another serial step 122 (shown in Figure 5B) where said continuous sheet of tobacco tissue 66 is converted into one or more coiled coils 66B of tobacco tissue that are ready for use by automatic manufacture of the cigarettes 23.

As shown specifically in Figure 5 A, process 120 for converting the tobacco raw material into a continuous sheet of tobacco tissue 66 begins with the tobacco raw material being subjected to an additional action step 124 (preferably with water) to separate the tobacco fibers from soluble tobacco substances in the original raw material. The tobacco raw material preferably consists of cut tobacco strips, but other forms of tobacco and/or tobacco leaves can also be suitably used in this preparation. It is preferred that the tobacco strip consists of a mixture of light and Burley types and may possibly also contain oriental or other types of tobacco.

The tobacco fibers collected from extraction process 124 are themselves subjected to a paper-type manufacturing process 126 to produce a continuous sheet or flake 68 of the base fabric.

In process 126, the tobacco fibers from the extraction step 124 are dispersed in water, where a predetermined amount of cellulose fibers is added, which acts as a reinforcing agent in the mixture used for the production of the base fabric 68. It is preferred that the cellulose fibers are cellulose pulp from wood, flax and/ or tobacco stalks. Once the mixture is prepared, the mixed dispersion of tobacco fibers and cellulose fibers is refined to form a tissue suspension 128 suitable for casting or application in step 130, where the tissue suspension 128 is directed to a casting box arrangement in a machine for producing said tissue , and here is cast on a fourdrinier net or on a stainless steel belt, preferably the first-mentioned.

It is more efficient to refine or purify the dispersed mixture of tobacco fibers and enhancers after the two components are mixed. They can of course also be cleaned separately and then mixed.

After casting step 130, the resulting fabric 132 is passed through one or more dryers in drying step 134, and this step preferably includes passing the fabric over a Yankee dryer and one or more drum dryers, although a variety of other arrangements and dryers can also be used. type that is known in the tobacco industry for carrying out the drying step 134. After the drying is over, the tissue is passed through a measuring step 136 to measure the moisture content and the weight of the dried tissue. The purpose of the measurement indicated by number 138 is to measure the moisture content and then possibly adjust the drying operation 134, thereby achieving and maintaining the final and desired moisture content in the sheet or sheet of the base fabric 68 for the subsequent coating operation 144. The sheet or sheet of the basic tissue 68 at this time contains approx. 15% moisture when brought in for coating in 144.

With respect to the measurement step 136, the result 140 with respect to the weight of the sheet of the base fabric 68 was used to adjust the operation of the casting step 130 so that the preferred base weight of the base fabric 68 is obtained as described earlier. Such adjustments include changes in the rate at which tissue suspension 128 is fed into the casting box in the tissue forming machine itself during casting step 130.

The tissue-forming step 126 may optionally further include a coating step 142 where one side of the base tissue 68 is coated with alginates in amounts described above and this takes place on the opposite side of the side that is to be coated with the tobacco flavor material 70. However, it is preferred practice that there is no imposition of algaecide.

After the fabric-making process 126 has ended, the base fabric has been produced in the form of a continuous sheet 68 which can then be subjected to a coating operation 144. Alternatively, the fabric can be taken out of the machine for a subsequent coating, but it is however preferred that this the coating 144 takes place immediately after the sheet of the base fabric 68 has been produced.

It is preferred that the base fabric 68 is fed into the coating part of the process with a moisture content of approx. 12 - approx. 17%, preferably 14.5 - 15.5% moisture.

From the extraction step 124, the soluble parts of the tobacco will leave this step in the form of a dilute solution containing approx. 5 - 10% dissolved constituents from the tobacco, more preferably from 7 - 8% dissolved substances. It is preferred that the diluted solution not be subjected to evaporation to minimize the application of heat to the solution. Application of heat can have a strong influence on the flavor provided by the dissolved substances from the tobacco when these are smoked as part of the cigarette 23.

These soluble substances (also known as "extracted liquid") from the extraction step 124 are mixed in a mixing step 146 with further finely ground tobacco, glycerine and pectin and together with water, all in relative amounts which make the final ratio of the components to be as previously described for the tobacco material 70 in a dry state. In connection with the mixing step 146, water added (or withheld) will provide sufficient amounts so that the dispersion after the mixing step 124 has a content of solids from approx. 20 - 35%, more preferably approx. 24 - 26%. The ground tobacco particles in the mixtures are preferably from 60 - 400 mesh, where the term "mesh" refers to 95% passage for the tobacco particles through a mesh layer where the given number is openings per square inch. It is more preferred that the added ground tobacco particles lie in the range from approx. 100-200 mesh, most preferred approx. 120 mesh.

If the mesh size of the ground tobacco particles is above 120 mesh, more specifically at or above 180 - 200 mesh, then one can increase the solids content of the stirred tobacco material after mixing step 146 to levels between 28-31%.

After mixing step 146, the resulting suspended tobacco material is directly fed into a coating operation 144, this operation can effectively be carried out at some point later in the manufacture. In the coating operation 144, the suspended tobacco material should have a content of solids from approx. 22 - 27%, more preferably from approx. 24 - 25%.

In the coating part of step 44, the stirred or suspended tobacco material will have a percentage by weight of dissolved tobacco substances of between 4 - 8%, more preferably from 5.5 - 6.5% by weight. When the stirred tobacco material is fed into the coating process 144, it should preferably have a temperature of about 20 - 45°C, more preferably at or around about 30°C plus minus 2°C.

The coating step 128 should preferably be carried out in the course of a standard reverse roll coater located after a Yankee dryer with an endless belt or a fourdrinier mesh. The coating itself can be carried out using any other suitable coating device of the type that is well known within the tobacco industry. The tobacco material 70 can instead be molded or extruded onto the base fabric 68. Alternatively, the application of step 128 can be carried out completely separately from the production of the flake of the base fabric 68. During or after the coating step 128, flavorings of a commonly known type from the cigarette industry can be added if this is desired .

After the coating is finished, a continuous sheet of tobacco tissue 66 will have been produced.

As shown in Figure 5B, the process will now take place through the steps 122 where the sheet of tobacco tissue 66 is converted into spun coils 66B of tobacco tissue which are suitable for the automatic production of cigarettes 23. It is preferred that the conversion step 128 is carried out on-line with the production of the continuous the sheet of tobacco tissue 66. When carrying out the transformation step 128, one should avoid conditions that could create breaks or tears or other damage to the sheet of tobacco tissue 66 so that one can achieve a continuous winding of the tobacco tissue on the coil 66B without any or only a few splices . Alternatively, the sheet of tobacco tissue 66 can be so-called conditioned so that after the conversion step 122 the tobacco tissue on the coil will not hang together and can be easily unwound from the coil 66B without breaking.

Conversion step 122 starts with a drying step 146 where the sheet of tobacco tissue 66 is passed through a gas-fired hot air dryer of the type sold by Airtech Systems Corp. of Stroughton, Maine or a hot air dryer heated by steam. You can of course also use other dryers of the type known within the tobacco industry. The drying step 146 should be carried out with minimal application of heat but. however, sufficient to dry the tobacco tissue 68 from its original state (approx. 15% moisture in the base tissue and approx. a moisture level of 75% on the coating itself) to approx. 8.5 - 12% total moisture after drying step 146 is complete. More preferably, the dried tobacco tissue sheet 66D has a moisture content of between 10 - 11%. This final moisture content is preferred for several reasons: this will facilitate splitting at a later stage of the conversion process 122, it provides a moisture content which means that the material will be in equilibrium when it is stored and/or transported to a manufacturing unit in addition to obtaining a moisture content which prevents the material from becoming sticky and causes the base fabric to stick together on spool 66B.

After the drying step 126, the dried tobacco web 66D is cooled to room temperature, preferably the same temperature as the tissue will be during storage or transport to a manufacturing site, usually in the range of about 17 - 25 C. The cooling step 148 not only facilitates the equilibration of the tobacco web 66 to the environmental variables found during later operation, but also avoids the risk of heat remaining inside coil 66B which could otherwise start a self-heating process. If this is not controlled, a self-heating can lead to extreme temperatures and degradation of the desirable qualities of the tobacco tissue 66. It is preferred that the cooling step is carried out with an air cooler that is cooled by means of cold water, and which is sold by Airtech Systems Corp. of Stroughton, Maine, although of course other cooling devices can also be used.

After the drying and cooling steps 146 and 148, the dried and cooled tobacco web 66 DC is passed through an uncoiler, for example, of the type sold by Thermo Electron Web Systems, Inc. of Auburn, Maine or another similar device of the type well known in the art. within the cigarette industry. After the uncurling step, the tobacco web 66 is substantially free of heat-induced curling or similar deformation along the edges and is in a condition for subsequent winding and splitting in steps 152 and 154. However, before carrying out these steps, it is preferred to measure temperature, moisture level and total weight of the tobacco web as it leaves the uncurling step 150, so that feedback and a check on the manufacturing process itself is obtained, which ensures that the tobacco web 66 is in a condition that is satisfactory for winding and splitting and that achieves the desired goals with regard to to temperature, humidity and total weight of the coils 66B.

By measuring different values in the tobacco crankcase 66, the reading, for example, of its total weight can be used to adjust the coating process 144, for example by adjusting the feed rate and quantity of the stirred tobacco material to said roll coating apparatus or equivalent machine. A reading of the moisture level in measuring step 151 is used to regulate the drying so that the desired moisture levels in the sheet are achieved as described earlier. In a similar way, cooling stage 148 will be controlled in relation to the readings taken of the temperature in the tobacco sheet 66 in measuring stage 151.

The tobacco warp 66 is then wound up in a winding step 152 which is carried out with winding machines of the type well known within the tobacco industry. Next, the coiled tobacco webs 68 are cut into individual coils where the cut width for each coil is the same as the desired circumference of the cigarette 23.

At the end of the conversion steps 122, the coil 66B will be in a state well suited for an automatic manufacturing process for the cigarettes 23, for example, the combined processes described with reference to Figure 6 of the pending US application No. 07/943,504 filed 11 .September 1992 which is included here in its entirety as a reference.

The glycerin in the tobacco material 70 serves as an aerosol precursor and enables the formation of a visible aerosol during the smoking of the cigarette'23. As the glycerine is released into the atmosphere, condensation will also occur and this gives an appearance of the type you would normally expect from cigarette smoke. Instead of glycerin, you can use other wetting agents suitable for use in the tobacco industry.

Optionally, after the molding step 123, alginate can be placed on one side of the fabric 68 before or after the coating step 126. The alginate layer provides additional strength and film formation on one side of the base fabric 68. However, the base fabric 68 will have sufficient strength without alganate, and it is therefore preferred to produce the tissue 68 without algenate.

The present invention can be implemented with other types of supporting tissue materials 68, this includes carbon fiber mats or metal mats of the type described in pending US patent application series no. 07/943,504 (PM 1550), series no. 07/943,747 (PM 1655 ); and US Patent No. 5,388,594 (PM 1697) and concurrent European patent application EP-A-0,615,411 all of which are incorporated herein by reference.

With respect to the carbon fiber mats described in EP-A-0,615,411 and US Patent No. 5,388,594 (PM 1697) and the continuation of which is filed in the pending application No. 08/380,718 filed September 30, 1995 (PM 1697 Cont.), then a preferred composition of such mats consists of a base fabric 68 of tobacco fibers in an amount of from 20-30 g/m . with approx. 24 -28 g/m and most preferred is approx. 26 g/m<2>, and carbon fiber in the range from 2 - 9 g/m2, more preferably 2-4 g/m2 and most preferably approx. 3 g/m2 and pectin in a range from 0.5 - approx. 1.5 g/m<2> and most preferably about 1 g/m2 pectin. It is preferred that these components are balanced so that a base fabric 68 is obtained with a total weight of approx. 30 g/m<2>. It is also preferred to use carbon fibers with a thread length of approx. 6 mm to facilitate their dispersion during the preparation of the suspension described above. Initial dispersion of a raw material consisting of carbon fibers is facilitated if one uses the methods described in US Patent Nos. 4,007,083 and 4,234,379.

In the alternative method with regard to the production of the tobacco base fabric 66 (ie carbon fiber mats) the final weight of the dry sheet will preferably be 160 g/m of which 30 g/m is the base fabric 68 itself while 130 g/m is the tobacco material 70.1 in contrast to this, the preferred embodiment of the tobacco base fabric 66 which does not include carbon fibres, will have a dry weight of approx. 170 g/m<2> of which 40 g/m<2> is the base fabric 68 and 130 g/m<2> is the tobacco material 70.

Regardless of the type of base fabric 68 or carrier material used, the tobacco material 70 is preferably placed on the inner surface of the fabric 68 and will release an aerosol of tobacco flavor when heated. Such materials may also include continuous sheets, foams, gels, dried suspensions or dried sputter-deposited suspensions of tobacco material.

Figure 3 and the descriptions included in US patent no. 5,388,594 (PM 1697), according to the preferred embodiment a cigarette 23 when inserted into the receiver sleeve 27 will be guided towards the heating element assembly 39 until the free end 78 of the cigarette 23 abuts against the stopper 182 which is firmly positioned at the bottom of the heating element assembly 39. As soon as the cigarette is in place, smoking will be able

begin, after which a drawing effect on the cigarette by a smoker will be sensed by the drawing sensor 45, which, together with the control circuit 41, causes an electric current to be fed to one of the preselected heating elements 37. Energy is supplied via an electric circuit which includes the conductor rail 183 in one end of each heating element 37, a

common ring 184 at the opposite end of each heating element 37 and conductor rails 186 that go from said common ring 184 back to the vicinity of the conductor rail 183. As each heating element 37 is activated, heat energy will be transferred through the cover 71 and the tobacco fabric 68 in a sufficient amount so that the tobacco flavor material 70 gives the tobacco tissue 66 releases a tobacco aerosol inside the tobacco stick 60 and which is then extracted from the cigarette 23 in relation to the sucking action exerted by the smoker at the tip end of the cigarette 23.

A smoker's puff on a cigarette will typically last from 1.5 - 2.0 seconds, while the FTC cigarette test methods assume a puff or puff of 2.0 seconds.

Where the footprint 94 of the heating element lies above the cavity 91, aerosol will be released directly from the heated tobacco flavor material 70 into the cavity 91 after which it is drawn in and through the tip 62 under very little pressure drop. On the other hand, where the footprint 94 of the heating element lies above the tobacco plug 80 (heating element - filler overlap 99), the proximal parts of the tobacco plug 80 will be heated together with the proximal parts of the tobacco tissue 66. Consequently, the mixed tobaccos in the tobacco plug 80 will contribute their own part of the total aerosol as a total contribution to taste and other subjective valuable properties. The aerosol that is released from the tobacco plug 80 at or around the overlap between the heating element and the tobacco filling is subjected to the same filtration and pressure drop as it is sucked through the tobacco plug 88 and into the cavity 91.

The aerosol produced by heating the tobacco plug 80 has a character and taste that can be changed by changing the mixture of the tobacco varieties as well as by adjusting how much the heating element 94 lies above the tobacco plug 80. The component of the aerosol produced near the cavity 91 is released more quickly from the cigarette because there is less heat resistance in the cavity 91 and because the heat-vaporizing tobacco substances in the cavity 91 are not subjected to a pressure drop from the tobacco plug 80 and instead will immediately communicate out to the tip 92 through the free-flow filter 74. However, this flow has a different character that is released from the tobacco plug 80 because it is essentially released from the tobacco flavor substances 70 on the base tissue 68. As will be described in detail below, it has been found that for the smoker's satisfaction the aerosol supplied from cigarette 23 should preferably include both aerosol components to ensure immediate supply to the smoker and to include you the flavor characteristics attributed to the mixture of cut tobacco. It will also be apparent from what is described below that the presence of the cavity 91 and its immediate rapid supply ensures a consistency from puff to puff when smoking the cigarette 23 and promotes uniformity between the cigarettes. This becomes clear when comparing the puff-by-puff characteristics of a partially filled cigarette 23 made in accordance with the preferred embodiment (with a plug of cut tobacco 80 and a cavity 91) in comparison with a cigarette 23 marked in a first alternative design (Fig. 6A) which does not have a filling of cut tobacco inside the rolled tobacco tissue, and another alternative design (Figure 7A) where the entire rolled tobacco tissue is filled with cut tobacco. When describing these alternative designs, it is understood that the tobacco fabric 66' and 66" consist of a base fabric 68 and a tobacco material layer 70 as in the preferred embodiment. The tobacco stick 60' in these alternative designs also includes a cover 71.

A tube type heating element with an energy input of 15 Joules was used to produce the comparable data shown in Figures 6B and 7B with respect to the cigarettes shown in Figures 6A and 7A respectively.

As shown in Figure 6A, a cigarette designed for smoking in an electric smoking system of a first alternative design consists of a tobacco stick 60' and a wrapper 62' each having components denoted by the same numerals corresponding to the components of the preferred embodiment as shown in Figure 4A. However, the tobacco stick 60' in the cigarette 23' does not include any cut tobacco within the tobacco web 66', and the free end sits at 8' on the tobacco stick 66' is provided with a backflow filter 200'. The base fabric 68' gives the tobacco fabric 66' is of the type that includes carbon fiber and as described previously. The construction of cigarette 23' is also described in detail in US patent no. 5,388,594 (PM 1697), which is incorporated herein in its entirety by reference. With regard to the description given in the following, a reference to this cigarette 23' will be indicated as a filler-free cigarette 23'. The experiments were carried out using a smoking machine as shown in Figure 6C together with a smoking system 21. The smoke production from the smoking machine was conducted during each puff through a smoke measuring device 6Y where there was a translucent chamber 6V where a light beam 6U from a source 6W was directed through this chamber 6V to a light detector 6C at the opposite end of chamber 6V. The measurements in this photosensor 6Z were then processed to measure the intensity of the light beam 6U as it hits the sensor 6C. Each tobacco aerosol passed through chamber 6C will have a light-scattering effect on the light beam 6U, so that a resulting change in the measured light intensity as carried out by photodetector 6Z will be inversely proportional to the total content of particulate matter (TPM) in the aerosol. .

In accordance with FTC cigarette testing practice, it is preferred that the smoking machine draws a standard 2 second puff from the smoking system 21.

The information shown graphically in Figure 6B shows the intensity recorded in the smoke measuring device in relation to the time when the smoking machine goes through a succession of puffs on a refillless cigarette 23'. The indicated data indicate the following tendencies: that with a refillless cigarette 23', the first and second puffs will be inconsistent with the remaining 3 puffs, while the latter 3 puffs are far more consistent in relation to each other; and that the aerosol is supplied well before the end of the 2 second time set aside for each puff. The fillerless cigarette 23' is less constant with regard to supply in the first puffs and a sustained consistency exists only for the last puffs. The data relating to the first puff is relatively constant with respect to the general observation that the smoking machine with respect to a refillless cigarette 23' delivers less aerosol during the first puff if certain adjustments are not made such as perforating the tobacco rod 60 or other devices such as described in US patent no. 5,388,594 (PM 1697).

Figure 7A shows another embodiment of an electrically operative cigarette 23" consisting of a tobacco rod 60" and a wrapper 62" whose components and location are the same as in the preferred embodiment shown in Figure 4A and where the corresponding components are designated with numbers with ". However, the cigarette 23' of Figure 7A includes a backflow filter 200" at the free end 78" and a column of cut tobacco 220' extending the entire length of the tobacco stick 60" between the backflow filter 200" and the freeflow filter 74" in the tobacco stick 60".

The tobacco column 220" in the cigarette 23" is composed of a mixture of Burley, light and oriental tobacco with a stick density of 0.275 g/cm<2>. The base fabric 68" in the tobacco fabric 66" is of the type that includes carbon fiber as previously described. In the discussion given below, the cigarette 23" will be referred to as a cigarette 23" filled with cut tobacco.

Figure 7B shows the measurements made of the light intensity from the smoke measuring device 6Y and which were correlated with the time delay progression for each puff in a series of puffs numbered from 1 to 7 with said filled cigarette 23". The data indicated on Figure 7B are representative of two easily discernible tendencies when trying a cigarette constructed in accordance with the drawing showing a fully filled cigarette 23", that the first puffs give a significant aerosol supply, but that the supply then decreases to such an extent that the last 3 puffs give significantly less supply than the first ones (if no adjustments are made), and that for the completely filled cigarette 23" the aerosol supply will be delayed and that the first puffs (puffs 1, 2 and 3) will not achieve maximum supply until a significant part of a 2-second period.

During the first few days, the fully filled cigarette 23" will tend to deliver a greater volume of aerosol than the unfilled cigarette 23'. A comparison of the data presented in Figures 7B and 6B emphasizes the general observation that the total areas above the lines showing the first drags in Figure 7B for the fully filled cigarette 23" is greater than the total area above corresponding lines in Figure 6B for the unfilled cigarette 23'. The area above the line for each stroke in Figures 7B and 6B indicates the total supply under that stroke.

It is believed, however, that the delay in introducing aerosol into the fully filled cigarette 23" will cause a smoker to respond with a longer and stronger puff or drag in that he or she does not obtain an immediate taste response from the cigarette 23". This stronger draft can in turn cause the heated parts of the cover 71" and the tobacco tissue 62" to be more completely consumed (oxidized) by further air being drawn through the cigarette which gives a significant risk of breakage and perhaps also localized collapse of the tobacco column 220" below the first puffs. Furthermore, it is assumed that as soon as the pyrolysis has started in the fully filled cigarette, this will tend to be self-igniting because the presence of a larger mass of combustible tobacco and/or the filter is more compact. Because air is more easily drawn into the tobacco stick through the "burnt" positions during the first puffs, these localized breaks will presumably short-circuit the desired airflow in subsequent puffs. Consequently, the supply will decrease during subsequent puffs of the fully filled cigarette 23".

The data given in Figure 7B and the explanation given above are consistent with the general observation that a fully loaded cigarette 23" or a traditional cigarette, when smoked with electric lighters, tends to have a decreasing aerosol delivery during the later dragons.

Due to the delayed and partially self-sustained pyrolysis that occurs in the fully-filled 23" cigarette, it tends to develop a greater amount of aerosol in the final steps or stages of the puff, and may also be expected to produce a certain amount of aerosol beyond the period of time the cigarette is actually drawn or sucked on. The latter situation may result in the production of an "after-puff" aerosol which may remain inside the housing 33 of the lighter 25, particularly at or around the heating element assembly 39. Such "after-puff" aerosol will create problems by condensation on the heating elements 33 or remain in said location for a sufficient time to be drawn into the cigarette 23<*> during the next puff or puff In either case it will not provide a satisfactory and consistent taste experience.

The lines for the puffs shown in Figure 6B for cigarette 23' without filling show that the supply of aerosol becomes maximum (where the puff lines descend most) well before the 2-second duration that occurs with a standardized puff has ended, and that the supply is minimal in the later stages of the puff, so that there are no problems with the production of an "after-puff" aerosol in connection with this type of cigarette. As indicated previously, however, the unfilled cigarette 23' provides a smaller aerosol volume than the fully filled cigarette 23", and that it has inconsistency with regard to delivery over time during the first of several puffs and that it lacks several subjective characteristics and flexibility that it would otherwise be able to achieve if it had been filled with a mixture (or an unmixed one) of cut tobacco.

Figure 8 shows data from a comparative smoking on smoking machines using a smoke measurement device 6Y as described above for cigarettes constructed in accordance with the fillerless cigarette 23', the fully-filled cigarettes 23" and a partially filled cigarette 23 constructed in accordance with the preferred embodiment according to the present invention (as shown in Figure 4A). Carbon fiber mats were used as the base fabric in all of these cigarettes. It will be apparent from the subsequent discussion of the data shown in Figure 8 that the partially filled cigarette 23 according to The present invention provides more consistent delivery of aerosol during one puff of smoking. It avoids the drop in delivery that occurs in the last puffs of a fully filled cigarette 23" and is more consistent in delivery than the unfilled cigarette 23' during the first of several puffs .

The partially filled cigarette 23 examined for the data shown in figure 8 was half filled with a cut tobacco so that the overlap between the heating element and the cavity in the cigarette was relatively large, that is 6 mm. The heating elements 37 used to develop the data shown in Figure 8 were of a tube type and had a 15 Joule energy per heating cycle.

The data shown in Figure 8 is the amount of aerosol (in milligrams) developed during the first 2 seconds of each puff in a progression of puffs during the smoking of each type of cigarette. In relation to the data indicated in Figures 6B and 7B, an amount of aerosol as indicated in Figure 8 corresponds to an integration of (the area as defined above) for each drag line from 0 - 2 seconds in Figures 6B and 7B.

The data given in figure 8 clearly shows the drop in delivery experienced with a fully filled cigarette 23" as one progresses from the first puff to the subsequent puffs. In contrast to this, the unfilled cigarettes will have a corresponding drop in supply as with cigarette 23".

Data in Figure 8 also clearly shows that the partially filled cigarette 23 provides a consistent supply compared to the unfilled cigarette 23' throughout 6 puffs. This happens with the help of a contribution from the cut tobacco, both in terms of taste and subjective qualities.

Table II shows data relating to changes in the amount of overlap between heating element and cavity in a cigarette constructed in accordance with the present invention, and how this may affect the supply of aerosol. The data set out in Table II was produced using a smoking machine where one had a partially filled cigarette with a 32 mm tobacco stick, a 7 mm free flow filter in one tip of one tobacco stick and a 30 mm wrapper, and where the footprint of the heating element was 12 mm long and centered on the center of the tobacco stick in each cigarette.

Figure 9 shows a graphical representation of the total delivered particulate matter (TPM) delivered in relation to the size of the overlap in mm between the heating element and the tobacco filling. The data shown was developed using standard testing techniques to determine the FTC "tar" level using so-called Cambridge pads and 2-second puff intervals on a standard smoking machine. The cigarettes examined were partially filled cigarettes with a carbon fiber base fabric and an overall length of 58 mm except that the data indicated along the ordinate of Figure 9 was obtained using an unfilled cigarette with a carbon fiber base fabric and the same overall length. As the overlap between the tobacco and the heating elements was varied, the footprint of the heating elements was allowed to remain at a constant length and remained centered on the center point of the tobacco stick. Each increase in the overlap between the heating element and the tobacco thus created a proportional reduction in the overlap between said heating element and cavity. The heating element was of a hose type with a so-called heating element footprint of approx. 10 mm. An analysis of said data shows that a different order of magnitude prevails in these circumstances between total particulate material and the length of the overlap between the heating element and the tobacco filling. The data shown in Figure 9 and the separate set of data from Table II show that the amount of overlap between the tobacco filler and the heating element can be adjusted to achieve the desired levels of particulate matter and aerosol delivery in a partially filled cigarette 23 .

The adjustment of the size of the overlap between the heating element and the tobacco filling is the preferred method for achieving a desired "tar" level in a partially filled cigarette, partly because it has been found that changes in the size of said overlap have a more pronounced and controllable effect on said supply than, for example, changes in the rod density in the tobacco plug 80. This also makes it possible to choose the rod density in the tobacco plug 80 for purposes other than consideration of the tar content, for example to regulate or control loose ends and/or to create a desired degree of pressure drop and/or filtration at the free end 78 of the tobacco stick 60 or otherwise facilitate manufacture. It also makes it possible to change the tar supply among corresponding cigarette products without necessarily having to change the tobacco web 66 or the tobacco plug 80.

It is also advantageous to design the relative dimensions of the partially filled cigarette 23 and the corresponding dimensions of the heating element assembly 39 in the lighter 21 so that when a cigarette 23 is inserted into the lighter 21, each heating element 37 which is placed along the tobacco stick 60 will be like this that at least some if not all of the footprints from the heating elements lie just above the filled portion of the tobacco stick 60 (above the tobacco plug 80). Under such a design, the cavity 91 will nevertheless facilitate aerosol formation and help to cool the smoke. It is believed that the free flow filter 74 helps to promote aerosol formation in that there is a flow limitation for the aerosol constituents as they are drawn from the larger cavity 91.1. In this connection it is noted that the free flow filter 74 on the tobacco stick 60 has edges 73 and 75 at the transitions between the stick and the cavity 91 on the one side and between the rod and the free-flow filter 102 on the other. These edges 73 and 75 are a consequence of the free-flow filter 74 having a smaller inner radius than the other two adjacent areas (the cavity 91 and the space inside the free-flow filter 102 ).It is assumed that these edges 73 and 75 (and possibly also other adjacent portions of the free flow filter 74) promote turbulence and other flow conditions favorable to the formation of an aerosol from the gas phase and the particulate constituents released from the heated tobacco portions of the tobacco stick 60. Figure 10 shows a cigarette 23a constructed in accordance with another preferred embodiment e of the present invention and which has the same components and arrangements as indicated for cigarette 23 as shown in Figure 4a, but also has a backflow filter 200a placed in the free end 78a of the tobacco stick 60a. The backflow filter 200a prevents tobacco from the tobacco plug 80a from leaving the free end 78a. The free flow filter 200a may also be colored to indicate that the cigarette 23a is one to be used in an electric smoking device rather than one to be lit with a cigarette or with a regular cigarette lighter as is the case with more traditional cigarettes. Although the backflow filter 200a is shown as a separate component in the wrapped tobacco plug 80a, with regard to the manufacture of the cigarette 23a, one can combine the tobacco plug 80a with the backflow filter 200a with a plug cover (not shown). With said backflow filter, cigarette 23a can be equipped with a tobacco plug 80a with a lower stick density without risking problems with loose ends or the tobacco falling out of the tobacco stick 60a. As shown in EP-A-0,615,411 and in the pending US Patent Application Serial No. 07/943,504 filed September 11, 1992 (PM 1550) and US Patent No. 5,388,594 (PM 1697), the backflow filter 200a is designed so that the or partially limits the release of aerosol from the free end 78a of the tobacco stick 60a after a puff is finished and to create a pressure drop at the free end 78a so as to advantageously limit the amount of air sucked into the cigarette 23a from the free end 78a in relation to the amount of air entering along the sides of the tobacco stick 60a.

With respect to design techniques for the partially filled cigarette 23 according to the preferred embodiment, heat energies and the amount of overlap between the heating elements and the tobacco filling can be used to establish and/or adjust the supply with respect to a desired "tar" level. When designing such a new partially filled cigarette 23, one will thus have a choice with regard to densities and the tobacco plug 80 in order to thereby achieve the desired degree of pressure drop at the free end 78 and/or control the return flow in the same way as is achieved with a backflow filter 200a in the alternative embodiment 23a.

Figure 11 shows another cigarette 23b constructed in accordance with another preferred embodiment of the present invention and where the cigarette contains a tobacco plug 80b consisting of a low density portion 310b up to the cavity 91b and with a high density portion 320b near the free end 78b of the cigarette rod 60b. The cigarette 23b is designed in such a way that the footprint 94b of the heating element lies above the low-density part 310b in the tobacco plug 80b, which results in an improved supply with lower stick densities. The high density area in the filling 320b is positioned to avoid loose ends and limit the transmission of air axially through the rod 60b in a manner analogous to the backflow filter 200a.

Preferred designs of the heating elements are shown in Figures 12-21. These heating elements are suitable for use in any of the cigarette embodiments described here. that is, both fully filled, partially filled and unfilled cigarettes of the type shown in figures 4B, 6A, 7A, 10 and 11 and modifications thereof.

These heating elements provide improved mechanical strength during repeated insertions, adjustments and removals of cigarettes 23 and will consequently improve the development of aerosols from a heated cigarette while maintaining the requirement with regard to energy. It has been found that this developed aerosol tends to flow radially inward from a heating element that receives energy in pulses.

In general, it is preferred to have 8 heating element blades 121 which give 8 puffs by heating the blades 121 in order, thereby simulating the number of puffs one has in a normal cigarette. Specifically, the heating element blades 121 extend from the sleeve 110 so that a cylindrical arrangement of heating element blades is formed which can then receive an inserted cigarette 23. There is preferably a gap 129 between adjacent blades 121. . It may be desirable to change the number of puffs and consequently the number of heating element blades .121 which is obtained when a cigarette is inserted into the cylinder CR. The desired number can be achieved by providing a desired number of heating blades 121. This can be achieved by providing blades of equal or different size.

The heating element assembly is placed inside the cavity 27 in the lighter 25. The cigarette 23 is inserted, optionally with backflow filter 200, first into the opening 27 in the lighter 25

and into an essentially cylindrical space within the heating element assembly 39 defined by an annular sheath 83 having an open end for receiving the cigarette, a cylindrical air duct sleeve 87, a heating element 100 including blades 121, an electrically conductive rod or guide rail 104a which serves as a common supply to the heating elements in the heating assembly, electrically conductive positive rods and conductor rails 104b and spacer 81. The inner surface 81 of the spacer stops the cigarette 23 in a desired position inside the heating element assembly 39, so that the heating element blades 121 are placed next to the cavity 79 in the cigarette and in a preferred embodiment is positioned as described earlier with respect to figures 1 - 11.

The entire heating element assembly is essentially placed inside and fixed inside the house

31 in the front part 33 of the igniter 25. A front edge 93 of the jacket 83 is preferably

placed at or just outside the first end 29 of the lighter 25 and preferably includes a rounded part so that one can more easily lead the cigarette 23 in and out of the heating element assembly 39. The rods 104a and 104b are preferably placed in corresponding contacts (not shown) and thereby provide also support for the heating element assembly 39 in the igniter 25 and conductors or printed circuits leading from the contacts to various other electrical elements. Other rods can also provide additional support to strengthen the entire assembly. The rods 104a and 104b can consist of any suitable material and preferably consist of tin-coated phosphor bronze. The channels 47 in the spacer and the bottom plate 50 communicate with

the draft-activated sensor 45 and the light sensor 53 which will note the presence or absence of a cigarette 23 in the lighter 25.

As shown in Figures 12 and 13, the heater assembly 100 is a monolithic structure consisting of 8 heater blades 121 extending from a central sleeve 1110 in a symmetrical arrangement, or indicated below with reference to Figure 19 in a non-symmetrical arrangement. As can be seen from Figure 13, the heating element assembly defines a substantially circular insertion opening 360 with a throat 365 which guides the inserted cigarette towards the coaxially defined cylindrical receiver device CR which has a diameter somewhat smaller than the insertion opening 360. The latter is defined by the end parts 118b on the connected sections 118 of the heating blades 121 while the throat 365 is defined by the part of the section 118 which lies between the leading edge 118a and the end 118b. The insertion end 360 preferably has a diameter that is larger than the inserted cigarette 23 so that it guides the cigarette towards the receiver CR, while this has a diameter that is approximately the same as that found in the cigarette 23 to ensure a firm grip and a good transfer of heat energy. Cigarette 23 preferably has a diameter which is approximately the same as that found in ordinary known cigarettes. With the given acceptable manufacturing tolerances for cigarette 23, a gradual narrowing of the area or throat 365 in the transition between the distal end and the receiver CR will also serve to slightly compress the cigarette to thereby increase heat contact with the surrounding leaves 121 which form an inner wall in the receiver. As a non-limiting example, one can for example have an insertion unit 360 which has an inner diameter of about 9.27 mm ± 0.5 mm while the receiver CR preferably has an inner diameter of about 7.06 mm ± 0.5 mm. Blades 120 can be bent inward to increase heat contact with the cigarette by limiting the diameter of the cylindrical receiver.

Each U-shaped element blade 121 has a first section or foot 116a extending from a first end of the sleeve 111, and where a connecting section 118 is connected to the opposite other end of the first part or rail 116a, while the second part or foot 116b extends from the first end of the connected section 118 towards the sleeve 111. First and second legs 116a and 116b are separated by a gap 125 which may be relatively constant, and which are substantially parallel in each unrolled state as. shown in Figures 18 and 19 discussed hereinafter, and is continuous in the direction of cigarette insertion to reduce unwanted nipping in the cigarette and where the blades are oriented to define a cylindrical receiver CR for the inserted cigarette 23. The connecting section 118 has curved edges 118a which are in contact with the inner edge of the blade feet 116a and 116b so that an elongated U-shaped resistance path is obtained which is substantially parallel to the longitudinal axis of the inserted cigarette and extends along the cigarette as it is detailed below. The curved edges 118a preferably have a curvature of approx. 180°± 20° so that a U-shaped blade is formed and where the curvature is concave towards the sleeve 111 and convex towards the insertion opening 360. The first end of the first blade foot 116a on the sleeve 111 can have an increased width with the same thickness as part 115 relative to the first foot 116a to lower the current density and energy density in part 115 to reduce the resistance heating of this part. Furthermore, an increase in width will increase the mechanical integrity of the blade 121 by

sleeve 111.

The other end 122 of the second blade foot 116b is preferably elevated relative to the main portion of the blade portion 116b in a step shape to facilitate electrical connection with the respective positive rod 104b. More specifically, as shown in Figures 12 and 13, end 122 consists of three sections, namely a section 122a which is substantially a planar continuation of the main part of the second blade foot 116b, a transition section 122b which rises at an angle as shown, and a connecting end section 122c which is substantially parallel to section 122a. The size of the ends 122 may be wider than that found on the foot 122b to increase strength, to provide better contact area for positive connection to the connecting end section 122c and to reduce the current density and thereby resistance heating of the ends 122. End section 122c is preferably spot welded or otherwise electrically and mechanically connected by other techniques to the positive rod 104b.

Another embodiment for achieving the positive connection for the heating element blades 121 is shown in Figures 14 and 15. The connecting end 122 is preferably not stepped as shown in Figures 12 and 13, but rather is a substantially planar extension of the second blade foot 116b, which makes the production simpler. In order to reduce the possibility of short circuits that could occur from a contact between the positive end 122 with the sleeve 111 and/or part 115 of the first foot 116a,

for example, when the inserted cigarette is twisted or otherwise adjusted by the smoker, then an electro-chemical ceramic coating 300 is applied to the end 122, sleeve 111 and part 115 then particularly on the exposed edges of these elements.

It is preferred that the ceramic coating is applied by means of a commonly known technique, for example by plasma spraying, to the sleeve 111, the connecting end 122 and section 115 of the first foot 116a. It is preferred that the ceramic material has a relatively high dielectric constant. Any suitable electrical insulating material can be used such as alumina, zirconia, mulit, corderite, spinel, fosterite, combinations of these etc. It is preferred that zirconia or another ceramic material is used which has a coefficient of thermal expansion close to that found in the underlying metal structure to avoid differences in expansion and contraction during heating and cooling, thereby avoiding cracking and/or delamination during use of the cigarette lighter. The ceramic layer is physically and chemically stable when the heating element is heated. A thickness of about 0.1 - 10 mils or 0.5 - 6 mils, or more preferably 1 - 3 mils is preferred for the electrical insulator. It is preferred that part of the end 122 is not insulated. The positive rods 104b are then contacted as previously described to this exposed portion. In order to simplify the masking, a corresponding part of the section 115 is similarly not coated with ceramic material.

The ceramic material can also be applied, for example in the same step where the plasma spraying is carried out, to the gap 127 between the ends 122 and the section 115 of the first feet 116a and the gap 126 between the ends 122 and the sleeve 110, thereby forming a ceramic sleeve structure that increases the mechanical the integrity of the heater assembly as shown in Figure 15. The size of this ceramic sleeve structure may be larger than that shown. With or without this additional chemical application, the ceramic coating that electrically polishes the ends 122 and the width gaps 127 and 125 can be lowered or weakened while providing protection against short circuits. Consequently, the end section 122 and part 115 can make the first foot 116a have an increased area, thereby increasing the strength of the receiver part in the cigarette lighter, and in the case that a ceramic sleeve structure is used, the skeletal structure should also be increased and thereby strengthen the entire heating element assembly. In addition, such a ceramic coating will smooth out sharp edges of the type defining the openings or gaps 127 and 125, thereby reducing the possibility of snagging and damage to the cigarette, especially when it is inserted, removed or otherwise adjusted by the smoker. Alternatively, the entire blade 121 and, in particular, the first and second parts of the feet 116a and 116b can be completely coated on a surface, for example the outer surface facing away from the cigarette, on both the inner and outer surfaces and/or the edges defining the openings , with a ceramic layer, for example 2 mil zirconia which will strengthen the heating element blades while maintaining the desired openings. The leaves 121 can therefore be thinner, for example item 2 - approx. 6 mil, which increases the resistance in the heating element path and allows the leaves to be wider to have an increased heating surface in relation to the inserted cigarette 23 while maintaining the total resistance in the leaves. This increased blade width together with the ceramic layer will further strengthen the heating element's structure. Furthermore, the ceramic coating on the outer surface of the blades 121 facing away from the inserted cigarette will prevent heat loss from a heated blade to the surrounding atmosphere. The ceramic coating should preferably be applied by means of plasma spraying or another method described in relation to similar applications, and should preferably be applied by means of physical vapor deposition developed by means of electron beams to avoid residual stresses which may be occurred during the processing with the plasma spraying and the subsequent surface treatment and/or particle impact.

Each blade 121 forms a resistance heating element. More specifically, the first end 115 of a first blade section 116a is electrically connected to the negative pole of an energy source, and more specifically, an integral extension of sleeve 111 is either mechanically or electrically connected to this which in turn is electrically and mechanically connected to the negative rod 104 by means of welding or other means such as soldering or brazing. Preferably, the two terminal rods 104 should be used to provide a balanced support base as the negative and positive connections also serve to mechanically support or carry the heating elements. The sleeve 113 thus serves as an electrical connection for all heating element blades n12l: In each of these embodiments, the negative connection for each heating element blade can be made individually, for example by a suitable negative contact which is placed on the end of the heating element opposite the respective positive contact areas 122.

A corresponding positive connection for each heating element blade 122 is made at the connecting end portion 122 of the second blade portion 116b as indicated above. Said connecting end section 122c is electrically isolated from said sleeve 110 by an opening or gap 127; from first blade section 116a and then especially first end 115 of heating element blade 120 by an opening 125, and from adjacent or adjacent heating element blade by means of opening 131 to avoid short-circuiting and to enable thermal expansion. In addition to this, specified ceramic coatings may be required. Alternatively, the connecting end sections 122c may respectively be connected to ground.

The indicated positive and negative connections provide a resistance path, and more specifically a circuit for the current that is applied from the electrical energy source, for example by means of a control circuit, to one or more special blades 120 when the smoking system is activated by the smoker's drag on the cigarette. The primarily heated area or area on the blade consists of a first blade foot 116a, the edge part 118a and a second blade foot 116b. Accordingly, a portion of the inserted cigarette 23 adjacent to and contacting the actuated blade 121 extending along the cigarette will be heated by means of an outer pattern corresponding to the heated portion of the blade, i.e. an elongated U-shape corresponding to the overlying leaf, primarily via conduction and radiation, however, so that a certain convection occurs. In addition, the part of the inserted cigarette between said feet, i.e. which lies below the opening 125, will be heated to a certain extent by a combined radiant and conductive heat transfer from both parts 116a and 116b. If opening 125 is not too large, the desired overlap will not occur and the part of the inserted cigarette that lies below this opening will thus not be sufficiently heated. Furthermore, said radiant heat and conduction heat will heat up parts of the inserted cigarette somewhat beyond the outer edge of the heating blade feet 116a and 116b. The various heated parts together constitute a heated area on cigarette 23 which extends somewhat past the outer edge of the foot 116a, below foot 116b, above the opening 125 and below foot 116b and somewhat past foot 116b of the actuated blade 121, and this corresponds to a drag with regard to developed tobacco taste. The size of the heated part will depend on the blade's geometry and heating properties as well as the length and strength of the energy pulse. Preferably, the blade is so designed both with respect to size and heat that it heats a segment of the inserted cigarette of sufficient size, i.e. about 18 mm<2>, which provides an acceptable draw to the smoker in relation to a draw-activated energy impulse .

The relatively larger blade end areas 115 and 122 which are part of the current path are not heated under these operating temperatures due to their larger volumes and thereby lower current density and thereby lower resistance heating. Furthermore, part of the connecting end section 118 will not be heated to these operating temperatures as the heat path tends to follow edge 118 and because this section has a relatively larger volume and consequently lower current density and thereby lower resistance heating than edge 118a and immediately adjacent sections. To further reduce unwanted heating of the remaining portion of portion 118, one may (1) increase the thickness of the monolithic material in portion 118 relative to the curved edge 118a in a region 118c to thereby reduce the current density and resistive heating as shown in FIG. 5. use a heat insulator

non-conductive material, for example a heat insulator, for example of a ceramic material. Examples of suitable ceramic materials include aluminum oxide, zirconia, a mixture of aluminum oxide and zirconia, mulit, etc., i.e. the same materials that were possibly used on the heating blades. Each of these modifications must be evaluated for any detrimental effects on the mechanical integrity of the connecting parts 118 which carry the heating assembly 100 and which define an insertion and withdrawal opening for the cigarette.

After a heating element blade 121 has received an impulse of electrical energy, a predetermined minimum time elapses before another draw is allowed. Premature heating of a part of the cigarette could also result in an unwanted and/or partial aerosol development or a heat-induced breakdown of the cigarette part before the desired heating is achieved. A subsequent reheating of a previously heated part can also result in undesirable taste qualities.

If a longer draft than that achieved by a single pulse in a single heating blade is desired, then the control pattern can be configured to heat the subsequent heating blade(s) immediately after energizing the first heating blade with a pulse, or during part of the first heating, whereby another segment of the cigarette is heated. Said additional heating element blade can be the one which radially lies successively next to the first blade or another. The heating element blades should be of such a size that the total number of drafts of a desired duration is achieved.

In one embodiment, the number of heating element blades 121 will correspond to the number of desired puffs, i.e. 8.1 another embodiment, the number of shaped heating element blades 121 will be twice the number of puffs, i.e. there are 16 parts with heating elements for 8 puffs on a cigarette. In such a configuration, it is possible to have different firing sequences than the normal one, where each supply of energy lasts for approx. 2 seconds, and you can have different heating sequences than the normal one where the number of heating blades 121 corresponds to the number of puffs on the cigarette. For example, the circuits can be designed so that 2 heating elements are on the opposite side of the perimeter of the heating assembly, i.e. leaves that are separated by 180°, can be heated at the same time so that a suitable amount of aerosol is developed from the cigarette in relation to one puff on this. Alternatively, a first heating sequence for every other heating leaf 121 for a cigarette can be followed by another sequence where the intermediate leaves 121 are heated for the next cigarette. Alternatively, a first heating sequence can be repeated a predetermined number of times for a number of cigarettes, after which a new heating sequence can be started. In this respect, any combination of heating blades can be used. The number of heating blades can be less than, equal to or greater than the number of puffs used for a single cigarette. For example, a niblad system can be used for a 6-puff cigarette, and where another set of 6 heating blades is heated for each subsequent cigarette while the connected set of the remaining 3 blades is not heated.

The heating assembly 100 is electrically and mechanically relatively firmly mounted at one end via welding of the rods 104a to the sleeve 110 and the rods 104b to the end 122. The rods 104a and 104b are preferably molded in advance into the plastic sleeve or otherwise firmly connected to it, preferably in a way that results in minimal lye leakage. It is preferred that this fixed end is opposite the insertion opening 360. The connecting sections 118 and then specifically the opposite ends 118b opposite the connecting edges 118a define the insertion opening 360. The end sections 118b may have a tube outward to define a throat section 365. The blades 121 are then narrow from this section so that an inner diameter is obtained which is somewhat smaller than the outer diameter of the inserted cigarette 23, that is to say that the middle point of the blades provides the desired heat contact, that is to say that there are compressive forces between the blades and the cigarette. The end sections 118b are free so that they can expand when heated, that is, the sections 118b are not fixed. Most specifically, each end section 118b is located within a corresponding channel 210 located in the inner wall 201 of the igniter end cap 83. More specifically, the radially outward movement of the end sections 118b on the inward facing blades 121 will be stopped by the ends 118b contacting the radially outward wall in channel 210, thereby establishing a limit for the deflection and defining the entry angle as such. This entrance angle can also be changed as previously described. As shown, the inner wall 201 has an outgoing slit which enables part of the blade ends 118b to be inserted. This radially extending wall of channel 200 contacts the end 118b and is designed in such a way, both in terms of size and configuration, that a suitable length of the blade end 118b can be inserted so that the blade end will not fall out of the channel 210 during heating or cooling of the blade or when one puts in or takes out the cigarette. If desired, this radially outwardly directed channel wall may be provided with a stop, for example a trapezoid, which contacts the ends 118b. In an alternative embodiment, a portion 118b of the blade end 118b will be rounded, more specifically elliptical, before the inserted end portion 118b. This rounded part 118b allows the inserted part to move in the channel 210 in relation to heat-induced or mechanically induced movements, whereby the inserted part of the blade end is kept inside the channel 210.1 addition or alternatively the blade ends 118b can be more rounded.

In a first embodiment of the type shown in figure 3, channel 210 has such a size that the end 118b of the heating blade 121 can expand or expands towards the end surface 202 of channel 210 when the cigarette 23 is inserted and/or a blade is heated, as that the desired contact between the cigarette and the heating blades is achieved. Such an arrangement where one end of the blade is relatively free in relation to the oppositely placed sleeve means that a mechanical displacement and/or thermal expansion or contraction of the heating blades 121 in the longitudinal direction can be obtained when the cigarette is respectively inserted or removed or the blades is heated or the blades are cooled, thereby reducing tensions. In another embodiment shown in figure 14, a stopper 204 which may be trapezoidal is placed inside the channel 210 so that when the heating blades 121 expand upon heating or are displaced when the cigarette 23 is inserted, the end 118b will come into contact with the stopper 204 and provide a pivot point which means that blade 121 will bend inwards towards the inserted cigarette 23, thereby reducing the tension in the blade and increasing the desired heat contact, that is the compressive forces between the blade and the cigarette. By wobble point it is understood that blade 121 can rotate freely, but preferably not twist at this stopper 204.

The heating assembly 100 is thus preferably a monolithic structure which is optionally coated with a ceramic substance as described earlier. The sleeve 111 and the heating blades 121 are made of a material with the desired electrical resistance and strength. For example, it is preferred to use materials with an electrical resistance of approx.

50 - 500 u.ohm.cm, more preferably 100 - 200 uohm.cm, so that one reaches

temperatures of approx. 200 - approx. 1000°C, preferably approx. 400 - approx. 900°C and more preferably approx. 300 - approx. 850°C in the activated blade 120 for a period of from 0.2 - approx. 2.0 seconds with a pulse of approx. 50 Joules, more preferably approx. 10 - approx. 25 Joules, and most preferably approx. 20 Joules. The material should be able to withstand approx. 1800 - approx. 10,000 such pulses without failure, specific breakdown or unwanted seepage occurring in the blades 121.

The materials chosen for manufacturing the heating element blades 121 are preferably chosen so that they can be used repeatedly, that is to say at least 18,000 on/off cycles without failure. The heating element assembly 39 is preferably replaceable and separate from the igniter 25 and this includes the power source 37 and the electrical circuits used, which are preferably replaced after approx. 3600 cycles or more. The materials in the heating elements and the other metallic components are also chosen because of their oxidation resistance and general lack of reactivity so that it is ensured that it does not oxidize or otherwise react with the cigarette 23 at any temperature that may occur in the lighter. If it is desired can

the heating element blades 121 or other metal components are encapsulated in an inert heat-conducting material, for example a suitable ceramic material to avoid oxidation and reaction.

However, it is preferred that the heating element blades 121 and other metal components are made of a heat-resistant alloy that exhibits a combination of high mechanical strength and resistance to surface oxidation, corrosion and breakdown at high temperatures. It is preferred that the heating element blades 121 are made from a material that has high strength and surface stability at temperatures up to approx. 80% of their melting point. Such alloys include those commonly referred to as superalloys and are usually based on nickel, iron or cobalt. For example, it is suitable to use alloys primarily of iron or nickel with aluminum and yttrium. It is further preferred that the alloy in the heating element blades T21 includes aluminum in order to improve the effect of the heating elements, for example by thereby providing resistance to oxidation.

Preferred materials include iron and nickel aluminides, preferably those

alloys that are described in the pending US patent application serial no.

08/365,952 filed Dec. 29, 1994, and more particularly serial no. filed concurrently entitled "Ferro-Aluminum Alloys for Use as Electrical Resistance Heating Elements" (Attorney Docket, No. PM 1769), as herein in its

the whole is included as references.

Several elements or elements can be used as additives to the aforementioned NisAl alloys. B pg Si are the principle additions to alloys for the heat layer 122. It is assumed that B improves the grain boundary strength and is most effective when a NiaAl

the alloy is nickel-rich, that is, the aluminum content is equal to or less than 24 at.%. Si is not added to the N13AI alloys in larger quantities, as the addition of Si beyond 3% by weight will cause silicides of nickel to form and this will

on oxidation lead to SiCv The addition of Mo improves strength at low and high temperatures. Zircon will give you an improved resistance to oxide splitting during repeated heating and cooling. Furthermore, Hf can also be added to improve the high temperature strength. Preferred Ni3Al alloys for use as substrate 300 and as heating element 122 are designated IC-50 and specifically contain approx. 77.92%

Ni, 21.73%A1, 0.34 Zr and 0.01% B in "Processing of lntermetallic Aluminides" by Sikka, lntermetallic Metallurgy and Processing-Intermetallic Compounds editor Stoloff et al., Van Nestrand Reinhold. NEW. 1994, Table 4. Different elements

can be added to the iron alum. Possible additions include Nb, Cu, Ta, Zr, Ti. Mr,

Si, Mo and Ni. The heating material can be Haynes 214 alloys (Haynes alloy No. 214, a nickel-based alloy containing 16.0% chromium, 3.0% iron, 4.5% aluminum, traces of yttrium and where the rest (about 75%) is nickel , and where this alloy is commercially available from Haynes International Kokomo, Indiana), Inconel 702 alloy, MCrALY alloy, FeCrALY, nichrome brand alloys (54 - 80% nickel,

10 - 20% chromium, 7 - 27% iron, 0 - 11% copper, 0 - 5% manganese, 0.3 - 4.6% silicon,

and some contain 1% molybdenum and 0.25% titanium; nichrome I is indicated and contains 60% nickel, 25% iron, 11% chromium and 2% manganese; nichrome II contains 75% nickel, 22% iron, 11% chromium and 2% manganese, while nichrome III is a heat-resistant alloy containing 85% nickel and 15% chromium), as described in the pending patent application no 08/ 380,718 filed Jan. 30, 1955

and US patent no. 5,388,594, or you can use materials with similar properties.

As shown in Figure 12, the heating element blades 121 can be arranged so that they stand out symmetrically from the sleeve 111. Alternatively, non-symmetrical arrangements can be used. For example, a row of 6 or 8 heating element blades 121. can be divided into, for example, 2 equal-numbered subgroups, for example 3 or 4 blades. The heating element blades in each group can then be separated by an opening 131 as discussed earlier. The subgroups are separated by a larger space 135 as shown in Figure 19 in a flat state. The opening or distance 135 is defined in such a way that a minimal conduction is obtained with regard to heat transfer between the adjacent blades 121 in the adjacent subgroups, that is to say to the part of the cigarette that lies below the opening 135. The opening 135 thus provides a wider unheated and robust part a<y> the cigarette which is stronger than the unheated parts of the cigarette which lie below the narrower openings 131, whereby a column of strength is obtained in the cigarette 23 which means that the cigarette can be more easily removed after smoking and corresponding heating. If desired, the electrical circuits can activate more than one

heating element blades simultaneously in such symmetrical or non-symmetrical arrangements.

The present invention has two heating element feet or wires 116a and 116b separated by a space 125, and this results in a significant improvement in the amount of aerosol developed compared to the amount developed by an entire heating element. The latter provides good heat transfer with the cigarette, but the mass transfer of aerosol into the drawn air flow will be weakened due to the fact that the solid structure blocks the optimal introduction of air placed on the outside of the cigarette, especially if the housing of the smoking system itself is equipped with perforations for communication with air from the outside to the outer surface of the cigarette. A heating element according to the present invention has the same volume as a

full heating element blade. but has a larger perimeter, which means that there is a higher possibility of air intake, that is, because of the opening 125, which consequently results in an improved supply of flavor per unit of energy to the blade 121. As

mentioned earlier, the opening 125 should be of such a size that optimal radiation overlap is obtained for a given blade geometry. As a higher amount of aerosol is developed, the required mass with respect to the leaf volume can be reduced while developing the same amount of desirable flavoring substances, which results in a lighter unit and less energy needed to adequately heat the heating leaves 121 and the inserted cigarette, which in turn reduces the weight of the device as the power source, i.e. the batteries, can be made smaller. It can be mentioned as a non-limiting example that the opening 125 can be approx. 0.1 mm ± approx. 0.12 mm wide, the blade threads or feet 116a and 116b may be approx. 0.31 mm - approx. 0.43 mm ± approx. 0.12 mm wide and approx. 14 mm ±0.12 mm long, and approx. 0.2 mm - approx. 0.25 mm thick ± 0.12 mm, while the length from the edge of the sleeve 110 to the tip of the connecting section 118 can be approx. 27 mm ± 1.5 mm.

It has been found that the primary transverse or radial air flow in relation to the inserted cigarette results in a more desirable smoking development than a primarily longitudinal flow. The openings 125, 127 and 131 provide paths for the air which can thereby be drawn into contact with the inserted cigarettes. Additional air passage is provided so that an optimal transverse air flow is obtained by perforating sections of the heating blades.

Another embodiment of the blade geometry is shown in Figure 16 where both a first thread or foot 116a and another 116b are shaped like a snake. The snake shapes of said threads 116a and 116b are parallel so that the threads or feet have an even distance from each other, and this opening 125 is also snake-shaped. Such a snake shape increases the length of the blade edge, which results in improved aerosol entrainment. This form of tubing is described in more detail in EP-A-0,615,411 and co-pending patent application serial no. 08/380,718 filed January 30, 1995 and US patent no. 5,388,594.

A first method of manufacturing will now be described with reference to Figures 18 and 19. The manufacturing sites defined here can be carried out in any desired order to achieve high manufacturing speed, material savings, etc.

A sheet or strip of a suitable material with a thickness of, for example, 2 - approx. 20 mil, for example 10 mil is shaped so that a number of blades 21 are produced which go out essentially vertically via a first blade section 116a and vertically out via a first end section 115 from an essentially straight section 11 la in a chamber-like arrangement . The blades 121 are substantially parallel to each other and the opening 113 is located between opposite edges of the second blade section 116b of one blade and the first blade section 116a of an adjacent blade. As mentioned earlier, the blades 121 can either be symmetrically arranged with equal openings 131 between them as shown in Figure 18, or they can be non-symmetrically arranged, for example with equal openings 131 between adjacent blades 121 defined in subgroups 121a and 121b and a larger distance l33 between the two subgroups with a width X as shown in figure 19. It should be noted that the straight section Illa has two end parts with a length that is at least half the length of half X so that the distance 133 is formed when rolled up. These end pieces should be longer than X to get an overlap for connection. By way of a non-limiting example, it can be mentioned that opening 131 can be approx. 1 mm ± 0.12 mm wide in each of the versions, while opening 135 can be approx. 3.17 mm ± 0.12 mm wide in a non-symmetrical design.

The leaves are designed as described earlier so that they form the aforementioned dressing part 118 and the threads or feet 116a and 116b.

This formation of a plate or a strip of the material of the specified design is carried out by means of conventional techniques, such as punching or cutting, for example with a CO 2 or Yag laser. If one strip format is used, then the number of heating blades 121 produced from the strip may exceed the number required for a single cylindrical heating element arrangement. The straight strip can then be cut if necessary to produce sections Illa with the desired number of heating blades 121. The step shape if this is used on sections 122a and 122b and 122c then this can be produced via punching.

If the ceramic coating 300 is used, this can be applied by masking the punched profile and then heat-spraying the coating on section 11 la, 115, 122 and the whole blade or part of it so that the pattern previously described is obtained. Alternatively, the ceramic coating can be applied after the rolling step using this method and, if desired, before making the blades. As is well known, suitable masking can be carried out before manufacturing the heating elements and thereby the ceramic coating can be deposited in defined areas.

Section or partial piece Illa is then rolled so that a round casing 111 is formed. Section Illa can be rolled in any desired direction. It is preferred that said section is rolled so that the positive contacts 122c in the end part 122 are on the outer surface of. the manufactured cylindrical heating element, that is, on the opposite side of the cigarette to facilitate the connection with the rods 104b and to avoid damage during insertion and removal of the cigarette. The coiled heating element can then be rolled to a smaller diameter than the desired desired diameter and can then be inserted into the assembly itself. The coiled section can be expanded and further held in shape by means of the electrical connections. Alternatively, the coiled section can be connected via any known welding technique, for example either spot welding or laser welding to produce the filter 111.

It is preferred that a bevel is inserted on each blade 121 so that the threads or feet 116a and 116b and the connecting edge 118a exert a compressive

force on the inserted cigarette when the heat assembly itself is formed as it is

shown in figure 13. This slanting should preferably take place before the roll-up, but can also be carried out after this. This oblique angle increases the heat contact between the heating blade and the inserted cigarette to improve the heat transfer effect.

The heat transfer effect is also improved by optimizing the size of the surface areas and blade threads or blade feet 116a and 116b which are in an effective heat relationship with the underlying cigarettes. As seen in Figure 17a, the underside 117 of the threads or feet 116a bg 116b (116a is shown as an example) is planar, that is, they are flat across the blade foot as previously described. To improve the heat transfer ratio, the underside 117 can be designed in various other ways, for example in the form of an angle or a curve to obtain maximum surface area of the heated foot relative to the cigarette without undesirably increasing the volume and consequently undesirably lowering the current density and the resulting resistance heating of the heating element's wire or foot, as shown respectively in figures 17b and 17c. The shaped underside 117 should preferably not penetrate any part of the cigarette 23 to avoid that this is weakened or that the cigarette is scratched during insertion, adjustment or removal. Rather, the center or top of underside 117 should contact or be in close thermal contact with cigarette 23, while the remaining portion of underside 117 is in a radiant heat relationship with cigarette 23.

It is preferred that the shape of the underside is obtained by punching out the threads 116a and 116b on the blade 121 while it is in an unrolled state. This punching can take place at the same time as performing the punching that is necessary to achieve the oblique angles mentioned above. The punching shapes the underside also increases the strength of the feet or threads 116a and 116b, thereby avoiding unwanted short circuits and deformations.

Another method of manufacture will now be described. A tube of a suitable material is provided. The blades 121 are then shaped by any technique, for example by laser cutting. Alternatively, the blades can be designed using a so-called sinking technique, where an inner mandrel is inserted into the tube in order to

get the specified blade profiles formed, after which another so-called winch, either internally or externally, is used to cut out the profile. A ceramic layer 300, if desired, can then be applied to the profiled tube.

The present invention also minimizes possible harmful heat-induced stresses. As the heating blades 121 and the sleeve 111 are monolithic, tensions arising between connections and discrete parts of a heating element will be avoided.

The various embodiments of the present invention are all designed so that the smoker can be supplied with an effective amount of a flavored tobacco reaction under standard conditions. In particular, it is of course understood that it is desirable to supply between 5 and 13 mg, preferably between 7 and 10 mg of aerosol to a smoker during a and 8 puffs, and where each puff has a volume of approx. 35 ml and has a duration of 2 seconds. It has been found that to achieve this, the heating elements 121 should be capable of supplying a temperature as described above when in a heat transfer relationship with the cigarette 23. Furthermore, the heating blades should preferably be capable of consuming the indicated energy. If the heating blades 121 are bent inwards towards the cigarette 23, this will mean that less energy is required to obtain better heat transfer conditions.

Of course, the resistance of the heating elements will be in a certain relation to the special energy source 37 which is used to supply the necessary electrical energy to be used to heat the heating blades 121. The above-mentioned heating element resistances correspond to designs where the power or energy is supplied by means of 4 nickel-cadmium battery cells which are connected in series with a total uncharged power source voltage of about 4.8 - 5.8 volts. In other alternatives, if one uses 6 or 8 such series-connected batteries, the heating element blades 121 should preferably have a resistance of between 3 ohms and approx. 5 ohms, or between approx..5 ohms and approx. 7 ohms respectively.

Another embodiment 450 of the present invention is shown in Figures 20 and 21 and consists of a series of heating elements 451. Each heating element 451 is in the form of an elongated "U" which each has both ends 452, 453 of their respective heating wires connected to the side wall of cavity 430 near the end wall 443 in this cavity 430. Each respective end 452 is individually connected to the control circuit and then to the electrical energy source for individual activation of the heating elements 451 while the ends 453 are connected together to earth. While the ends 454 near the mouth end of cavity 430 are not electrically connected and thus are not in contact with the side wall of cavity 430, it is nevertheless facing the side wall in this cavity as shown in both figures 20 and 21, where they provides some guidance for inserting the inserted cigarette as indicated above. It should be noted that in figure 21 the lower and upper elements 451 are shown in cross-section with their U-shaped tips 454.

Another embodiment 470 shown in figures 22 and 23 with the heating elements 471 placed somewhat further away from the wall of the cavity 430 and where each is provided with a somewhat sharper "V" tip 472 in addition to the indentation 473 to increase their rigidity. In this way, the heating elements 471 will really penetrate the cigarette and provide the desired intimate heat contact. The open-cell foam structure described above is very well suited for such a design. In this embodiment, because the heating elements 471 are at a certain distance from the side wall of cavity 430, the ends 452 and 453 are not attached to the side wall of the cavity 430 but to its end wall 443. It is preferred that the connections to the ends 452 and 453 and the end wall 443 are done via the spacers 480 which are not conductive either to heat or electricity. In this way, a broom-like effect will take the residues past the ends 452 and 453 and towards the spacers 480, where these residues avoid reheating as described in more detail in US patent no. 5,249,586. Perforations 412 are provided in the wall so that air from the outside can be drawn through part 420 as is described in detail in US patent no. 5,249,586 which is included here in its entirety as a reference.

It is obvious that one can easily carry out modifications and improvements without thereby abandoning the intention of the invention as these are described and defined in the following claims. For example, the cooling step may be performed before the cooling step in a modification of the part of the process described above with reference to Figure 5B.

Claims (91)

1. Cigarette (23), characterized in that it consists of a tobacco stick and where said tobacco stick (60) consists of a tubular tobacco web (66) and a plug of tobacco (80) placed inside said tubular tobacco web, and where said tobacco stick has a free end (78) and an opposite end (72); and where said tubular tobacco web consists of a base web (68) and a layer (70) of the tobacco flavor material carried by said base web, and where the latter is adapted to transfer heat from an electric heating element (70) to said tobacco flavor material, and where said tobacco stick (60) is adapted so that it can operatively receive an electric heating element (37) along said tobacco stick (60) in a position between said free end (78) and said opposite end (72), and where said plug of tobacco (80) is placed next to said free end and where said tobacco plug is set at a certain distance from said opposite end so that an empty space (91) is defined between said tobacco plug and said opposite end. 2. Cigarette according to claim 1, characterized in that said position along said tobacco stick is such that the position overlaps at least part of empty spaces (91) and overlaps at least part of said tobacco plug (80). 3. Cigarette according to claim 1 or 2, characterized in that said tobacco stick includes a free-flow filter (74) near said opposite end, and where said free-flow filter is placed at a certain distance from said tobacco plug (80) so as to define said empty space (91) between said free-flow filter and said plug of tobacco . 4. Cigarette and teeth adapted to a collaboration such as an electric smoking system, characterized in that said cigarette consists of a tube of tobacco tissue partially filled with cut tobacco so as to define a filled tobacco stem part and an empty tobacco stem part (91), and where said cigarette ( 23) and said teeth (25) are mutually arranged so that an electric heating element in the lighter at least partially lies above at least one of the filled or empty tobacco stick parts when the cigarette is in an operative position inside said teeth.. 5. Cigarette according to claim 4, characterized in that said filled tobacco stave part includes a tobacco plug and that said electric heating element lies above at least part of said empty space and lies above at least part of said tobacco plug when the cigarette is in said operative position inside the lighter. 6. Cigarette according to claim 4 or 5, characterized in that said cigarette has a free end and that said tobacco plug is placed close to said free end and in that said cigarette includes a tubular element set at a certain distance from said tobacco plug so that said empty space is defined by said tobacco stick between said free-flow filter and said tobacco plug. 7. Cigarette according to one of the preceding requirements, characterized in that said tubular element (74) is a filter. 8. Cigarette according to claim 7, characterized in that said tubular element (74) is constructed of a softened yarn material. 9. Cigarette according to claim 7, characterized in that said free-flow filter (74) is constructed of a molded material. 10. Cigarette according to one of the preceding claims, characterized by further consisting of a filter cover (62) near . said opposite end. 11. Cigarette according to claim 10, characterized in that said cover (62) includes another free-flow filter (102) near said opposite end and in that said cigarette further includes wrapping paper (64) attached to said second free-flow filter (102) at said other opposite end. 12. Cigarette according to claim 11, characterized in that said cover further includes a nozzle filter plug (104) near said second free-flow filter (102). 13. Cigarette according to claim 12, characterized in that said free-flow filter (74) on said tobacco stick (66) includes a first passage and said second free-flow filter (102) in said cover includes another passage, and where said first and second passage create a communication between said empty space and said tobacco stick and said nozzle filter plug (104), and where said second passage has a different inner radius that is greater than a first inner radius of said first passage (75). 14. Cigarette according to claim 12, characterized in that said tobacco stick further includes a backflow filter (200") at said free end. 15. Cigarette according to claim 12, characterized in that said tobacco plug (80b) includes a first part (320b) near said free end (78b) which has a higher density than said tobacco plug distally from said free end. 16. Cigarette (23), characterized in that it includes a tobacco stick (60) with a free end (78) with backflow resistance and an opposite end (72), and where said tobacco stick consists of a tubular tobacco fabric (66) which includes a layer of tobacco material (78) a current restriction (74) which is operative at said opposite end of said tubular tissue and tobacco (78, 80) and which is operatively placed close to said free end and at a certain distance from said current restriction, and where the tobacco consists of cut tobacco which partially fills said tobacco rod so as to define a filled tobacco rod part and an empty tobacco rod part, and where said empty part is placed close to said current restriction and where said tubular tissue is arranged so that it conducts heat received from said tubular tissue to said tobacco, and where said tobacco rod (60) is positioned so that during a puff on said cigarette with an application of heat along an area of said tubular tissue, at least part of the tobacco will release a ring of tobacco aerosol that is drawn through said current limiter. 17. Cigarette according to claim 16, characterized in that said current limitation (74) is defined by means of a tubular element. 18. Cigarette according to claim 17, characterized in that said tubular element consists of a first free-flow filter (74), and where this defines a first passage through the filter, and where the cigarette further consists of a cover (62) which includes another tubular free-flow filter (102) placed near said first free-flow filter and in said tobacco stick, and where said second tubular free-flow filter defines another passage through the filter, and where said first passage in said first free-flow filter is narrower than said empty part (91) in said tobacco stick and narrower than said second passage in said second free-flow filter ( 102). 19. Cigarette according to claim 18, characterized in that said cut tobacco forms a plug with ten Ibake current resistance. 20. Cigarette according to claim 19, characterized in that said part of said cut tobacco material (80) is located at the free end (78) and has a greater density than the remaining part of the cut tobacco which lies distally from said free end. 21. Cigarette according to claim 20, characterized in that said cover (62) further includes a nozzle filter (104) near said second free-flow filter (102). 22. Cigarette according to claim 20, characterized in that said tubular tissue includes a cigarette wrapper (71) around said tobacco stick (60), and in that said wrapper is attached to said tobacco stick by means of a wrapping paper (64). 23. Cigarette according to one of the preceding claims, characterized in that the tobacco or tobacco plug (80) consists of cut tobacco. 24. Cigarette according to claim 23, characterized in that said tobacco or tobacco plug consists of a mixture of cut tobacco, and where said mixture is a combination of at least two light, Burley or oriental tobacco types. 25. Cigarette according to claim 23 or 24, characterized in that said tobacco plug includes a cover (84) around the plug and placed around said cut tobacco material (80). 26. Cigarette according to claim 23 or 24, characterized in that said tobacco (70) is placed along the inner surface of said tubular tobacco tissue (66). 27. Cigarette according to claim 26, characterized in that said tobacco stick consists of a cover (71) placed around the outer surface of said tubular tobacco stick or stick part. 28. Method for improving the supply of smoke from a cigarette (23) operative with an electric lighter and where said cigarette consists of a tubular tissue (66) with a free end (78) and an opposite end (72) and where the smoke can be drawn from said opposite end, characterized in that said method consists of the following steps: establishing an empty part along said tubular tissue in a position close to . said opposite end and a tobacco-filled portion along said tubular tissue in a position near said free end; and placing an electric heating element in said electronic teeth at least partially above said filled part of said tobacco tissue while activating said electric heating element so as to produce a release of flavor components from said tobacco. 29. Procedure according to claim 28, characterized in that said placement step includes placing said electric heating element partially over both the filled part of said tobacco tissue and said empty part of said tobacco tissue at the same time as activating said electric heating element. 30. Procedure according to claim 28 or 29, characterized in that said liberated tobacco constituents are passed through a structure placed near said opposite end. 31. Tobacco web adapted for rolling into a tubular tobacco stick (60) in a cigarette (23) operable with an electric cigarette lighter (25) and wherein said tobacco web consists of a base web (68) and a tobacco material (70) placed along a first side of said base tissue; characterized in that said base tissue consists of a combination of tobacco fiber and cellulose fiber, and where said tobacco fiber and said cellulose fiber are combined in a ratio varying from approx. 2:1 to 4:1, and where said base fabric has a base weight varying from approx. 35 - 45 g/m<2>, and where said tobacco material has at least twice the basis weight of said basic tissue, and where said tobacco material consists of finely ground tobacco and extracted tobacco substances in a ratio varying from approx. 3:1 to 9:1, and et moisturizer in an amount of approx. 5 - 20 percent by weight of said material. 32. Tobacco tissue according to claim 31, characterized by the fact that the two-axis material has a basis weight that is 3 to 4 times higher than that found in basic tissue. 33. Tobacco tissue according to claim 31 or 32, characterized in that said tobacco material further contains pectin in an amount of up to 2 percent by weight of said tobacco material. 34. Tobacco tissue according to claim 33, characterized in that said base tissue consists of approx. 28 g/m<2> tobacco fiber and approx. 12 g/m<2> cellulose fiber or of wood pulp or flax pulp or tobacco stem pulp. 35. Tobacco tissue according to claim 34, characterized in that said tobacco material contains approx. 66-71 weight percent tobacco particles, approx. 16 - 20 percent by weight extracted solid tobacco substances, approx. 10 - 14 percent by weight glycerin and approx. 1 - 2 percent by weight pectin. 36. Tobacco web adapted for winding into a tubular tobacco stick (60) in a cigarette (23) operable with an electric cigarette lighter (25), and wherein said tobacco web consists of a base web (68) and a tobacco material (70) placed along a first side of said base fabric; characterized in that said base tissue is a combination of tobacco fibers with a component basis weight of approx. 20-30 g/m<2> and carbon fiber in a component base weight of approx. 2 - 9 g/m and pectin in a component basis weight of approx. 1 g/m<2>, and where said tobacco material has a basis weight that is 3 to 4 times that found in said basic tissue, and where said tobacco material consists of finely ground tobacco and extracted solid tobacco substances in a ratio varying from approx. 3:1 to 9:1 and a wetting agent in an amount from approx. 5-20 percent by weight in relation to said tobacco material. 37. Cigarette which is operable with an electric cigarette lighter, characterized in that the cigarette consists of a tubular tobacco stick (60) constructed or produced from a tobacco weave according to one of claims 31-36. 38. Cigarette according to claim 37, characterized by further consisting of a plug of cut tobacco (80) near the free end (78) of said tobacco stick (60) and at least one tubular free-flow filter (74) near the opposite end (72) of said tobacco stick and a void (91 ) placed between said plug of cut tobacco and said free-flow filter. 39. Method for producing a tobacco tissue (66) consisting of base tissue (68) and a layer of tobacco material (70) and where said tobacco tissue can be folded into a tubular shape as part of a cigarette (22) which is operative together with a electric cigarette lighter (25), characterized in that the steps: separating soluble substances (124) from the fibers in the tobacco raw material, and where said soluble substances are in a solution containing from 5 - 10 percent by weight of dissolved tobacco constituents; preparing (128) said base tissue by preparing a suspension of said separated tobacco fibers and mixing said stirred tobacco fibers with a suspension strengthening agent so that a stirred or suspended mixture is produced and casting (130) this on a tissue-forming apparatus; to produce (146) said tobacco material by mixing said 5-10 weight percent solution of tobacco constituents with additional tobacco particles, glycerin and pectin so that a dispersion of the tobacco material is formed and then adjusting the water content so that in said dispersion a solids content varying from about. 20 - 30%, to apply (144) said dispersion of tobacco material along said base tissue so as to form a sheet of said tobacco tissue; dries (146). said flakes of said cotton fabric to a moisture content in the range from approx. 8.5 - 12%; cooling (148) said sheet of said tobacco tissue; removing irregularities (150) from said sheet of said tobacco tissue; winding (152) said flakes of said tobacco tissue so as to form a roll of tobacco tissue; splitting (154) said roll of tobacco tissue so that a coil of tobacco tissue is produced. 40. Procedure according to claim 39, characterized in that said solution of dissolved tobacco substances contains approx. 7 - 8 percent by weight of dissolved tobacco constituents. 41. Procedure according to claim 39 or 40, characterized in that the ambient temperature is in the range 18.3°C to 26.7°C. 42. Procedure according to claim 39, 40 or 41, characterized in that the pectin is supplied as a component basis weight of approximately 0.5 to 1.5 g/m<2>. 43. Method according to one of claims 39 to 42, characterized in that the moisturizing agent is glycerin added in an amount i the area approximately 5 - 20% of the dry weight of the tobacco material. 44. Method according to one of the patent claims 40-43, characterized in that the amount of water is adjusted so that at the end of the mixing step you get a dispersion containing from approx. 24 to approx. 27% solids. 45. Method according to one of patent claims 44, characterized in that the amount of water is adjusted "so that at the end of the mixing step you get a dispersion containing from approx. 24 to approx. 26% solids. 46. Procedure according to claim 45, characterized by the fact that the tobacco particles lie in the area from approx. 100 - 220 mesh. 47. Procedure according to claim 46 characterized in that the tobacco particles are approx. 120 mesh. 48. Method according to each of claims 39 to 47, characterized in that said reinforcing agent in said suspension consists at least of wood pulp, flax pulp or tobacco stem pulp. 49. Method according to each of claims 39-48, characterized in that said application step includes applying or coating said dispersion of said tobacco material on said base tissue in a dry weight ratio of at least 3:1. 50. Procedure i. follow each of the requirements 39 to 49, characterized in that said application step includes applying or coating said dispersion of said tobacco material on said base fabric in a dry weight ratio of at least 3:1. 51. Tobacco tissue according to claim 36, characterized in that said tobacco fibers on a component basis weight are approx. 24 - 28 g/m , carbon fiber is on component basis weight approx. 2 - 4 g/m and pectin is on a component basis approx. 2.5 - 1.5 g/m<2>. 52.. Heating element (39) for use in a smoking system with a source of electrical energy for heating a cigarette, characterized in that the heating element consists of: an array of electric resistance heating element blades (121) defining a receiving chamber for receiving an inserted cigarette and positioned longitudinally of the inserted cigarette, and each blade consisting of a first heating element blade foot (116a) having a first end and a second end, a second heating element blade foot (116b) having a first end and a second end and a connecting section (118) connecting the second end of said first heating element blade foot and said first end of said second heating element blade foot; and wherein said first and said second heating element blade feet on each heating element blade are separated by means of a gap or distance (125), and and wherein said first end of said first heating element blade foot is adapted to be in electrical contact with the source of energy and wherein the respective resistance paths for heating are formed by means of said first heating element blade foot, said connecting section and said second heating element blade foot so that each of the said electric resistance element blades is respectively heated along said first and said second blades, which then in turn heats the inserted cigarette, and where said first ends of said first leaves have a common connection.. 53. Heating element according to claim 52, characterized in that said first end of said first heating element blade feet (116a) is grounded. 54. Heating element according to claim 52 or 53, characterized in that the other ends of the other heating element blade feet are jointly connected. 55.. Heating element according to each a<y> requirements 52 to 54, characterized in that the gap or distance (125) which separates said first and said second heating element blade feet is adjusted in such a way as to allow the penetration of an air stream into the heated cigarette when it is sucked on by a smoker. 56. Heating element according to one of claims 52 to 55, characterized by further including a supporting hub (111), where the first ends of each of said first heating element blade feet (116a) extend from . said bearing hub; and where said supporting hub is adapted to be in contact with the source of electrical energy so as to form a common supply to the first ends of said first heating element blade feet. 57. Heating element according to claim 56, characterized in that said other ends of said second heating element blade feet (116b) are adapted to be in electrical contact with the source of electrical energy, and where the respective resistance circuits for heating are formed such that they include said first heating element blade foot, said connecting edge section and said second heating element blades to heat respective said -electrical resistance heating element blades 121 which in turn heats the inserted cigarette. 58. Heating element according to claim 56 or 57, characterized in that the other ends (122) of said second heating element blade feet (116b) go towards said supporting hub (111) and are electrically isolated from this. 59-. Heating element according to claim 56 or 57, characterized in that the other ends (122) of said second heating element blade feet (116b) are separated from said hub by a gap. 60. Heating element according to claim 56, characterized by further including an electrical insulator applied to at least one of said hubs and other ends of said second heating element blade feet. 61. Heating element according to claim 56, characterized by further including an electrical insulator applied to at least one of the other ends of said second heating element blade feet and the first ends of said first heating element blade feet. 62. Heating element according to claim 56, characterized by further including an electrical insulator (300) which forms a ceramic hub supporting structure around said supporting hub (111), the other ends (122) of said second heating element blade feet (116b) and the first ends of said first heating element blade feet (116b). 63. Heating element according to each of claims 56 to 62, characterized in that said bearing hub and said blades are moriolitic. 64. Heating element according to each of claims 52 to 63, characterized in that said connecting section (118) further includes a free end (118b) to compensate for thermal expansion when the heating element is heated. 65. Heating element according to claim 64, characterized by further including a supporting structure (83) stationary located within the smoking system and defining channels (210) to receive the free ends (118b) of said connecting sections of said blades (121). 66. Heating element according to claim 65, characterized in that said channels (210) are arranged in such a way that they enable thermal expansion and contraction of said heating element blades. 67. Heating element according to claim 65 or 66, characterized by further including a pivot point (204) placed inside each of said channels, and where said pivot point is positioned such that the associated free end (118b) of said connecting section can revolve around said pivot points so as to tilt said first and second heating blade feet (116a) and (116b) inwards towards the inserted cigarette when heating the connected heating element blades. 68. Heating element according to one of claims 51 to 67, characterized in that parts of at least one of said first heating element blade feet (116a) and said second heating element blade foot (116b) are coated with a ceramic material (300) to strengthen and electrically insulate at least one of said first heating element blade feet and said second heating blade feet. 69. Heating element according to claim 67, characterized in that a part of said second heating element blade foot (116b) up to said ceramic material is adapted to be in electrical contact with the source of electrical energy. 70. Heating element according to one of claims 62 to 69, characterized in that said blades (121) are arranged in such a way that they slide and receive the inserted cigarette. 71. Heating element according to one of claims 52 to 70, characterized by ai the other end of said second heating element blade foot has a step shape, and said step shape includes an end section (122c) adapted to be in electrical contact with the source of electrical energy. 72. Heating element according to one of claims 52 to 71, characterized in that said first and second heating element blade feet (116a) and (116b) on a respective heating element blade (121) are essentially parallel. 73. Heating element according to one of claims 52 to 72, characterized in that said connecting edge has a curvature between approx. 160 and 200°. 74. Heating element according to one of claims 52 to 73, characterized in that an underside of at least one of said first and second heating element blade feet (116a) and (116b) that faces the inserted cigarette is essentially non-planar in a section across said heating element blade foot. 75. Heating element according to claim 74, characterized in that said underside is bent. 76. Heating element according to claim 74. characterized in that said underside is angled. 77. Heating element according to each of claims 52 to 76, characterized in that the majority of the electric resistance heating element blades (121) are placed in groups, and where the openings (133) between the groups are adapted so that they provide unheated parts of the inmate the cigarette and also provides strength and facilitates the removal of the cigarette after smoking. 78. Heating element according to one of claims 52 to 77, characterized by at least one of said first and second heating element blade feet (116a and b) being snake-shaped. 79. Heating element according to claim 78, characterized in that both said first and second blade feet are snake-shaped and substantially parallel so that the space between the feet is also snake-shaped. 80. Heating element according to claim 52, characterized in that at least one end of at least one blade (121, 122) is wider than the adjacent active part of at least one of said feet, and where the end of said foot has lower current density and lower resistance heating than the active part of said foot. 81. Heating element according to one of claims 52 to 80, characterized in that said connecting section (119) is perforated. 82. Heating element according to one of claims 52 to 81, characterized in that said first and second heating element blade feet (116a, b) are slanted inwards towards the inserted cigarette. 83. Heating element according to one of claims 52 to 82, characterized in that said first and second heating element blade feet (116a, b) and said connecting edges have a resistance of from approx. 100 - 200 uohm.cm. 84. Heating element according to one of claims 52 to 83, characterized in that the said first and second heating element blade feet (116 a, b) and said connecting edges have a resistance of approx. 50 - approx. 500 u.ohm.cm. 85. Heating element according to one of claims 52 to 84, characterized in that said first and second heating element blade feet (116a, b) and said connecting edges are capable of reaching a temperature of approx. 200° to approx. 1000°C in from 0.2 to approx. 2.0 seconds with a pulse of approx. 10 to approx. 50 Joules. 86. Heating element according to claim 85, characterized in that said first and second feet (116a and b) and said connecting edges are able to be pulsed to these temperatures approx. 1800 to approx. 10,000 times. 87. Heating element according to claim 53, characterized in that the opening (125) which separates said first and second heating element blade feet (116a and b) is designed in such a way with respect to distance that a maximum collecting radiant heat is obtained from each of said first and second heating element blade feet on a connected heating element blade to a part of the inserted cigarette that lies below the opening. 88. Heating element according to each of claims 52 to 87, characterized in that said first and second heating element blade feet (116a, b) and said connecting edge section consist of an electrical resistance material selected from the group consisting of iron aluminides and nickel aluminides. 89. Electric smoking system, characterized by comprising a cigarette according to any one of claims .1 to 3 and a lighter, the latter having a series of resistance heating element blades defining a receiving chamber for receiving the heating element blades, such that the blades at least partially overlap said tobacco plug when said cigarette is inserted into said receiver chamber. 90. Electric smoking system according to claim 89, characterized in that said heating element blades run along the entire length of said tobacco plug and partially overlap said empty space. • 91. Electric smoking system according to claim 89 or 90, characterized in that the lighter includes a heating element according to each of claims 52 to 88.