WO2011121325A1

WO2011121325A1 - Smoking article

Info

Publication number: WO2011121325A1
Application number: PCT/GB2011/050494
Authority: WO
Inventors: Richard Fiebelkorn; David Dittrich; Kevin Blick; Mike Simpson
Original assignee: British American Tobacco (Investments) Limited; British American Tobacco Japan, Ltd
Priority date: 2010-03-29
Filing date: 2011-03-14
Publication date: 2011-10-06
Also published as: JP2011205915A; AR081528A1

Abstract

A smoking article (50) comprising a source of smokable material (51), and a sleeve (53) configured to be movable relative to the source of smokable material. A filter (54) is coupled to the sleeve. The smoking article is configured such that the position of the sleeve (53) relative to the source of smokable material determines a property of the filter (54) of the smoking article.

Description

Smoking article

Description

The present invention relates to a smoking article. In particular, the invention relates to a smoking article having a variable filter.

An extendable cigarette is known from US 2,820,462. The cigarette is telescopic, with a tobacco rod slidable within a tube having a filter at the mouthpiece end. The tobacco rod can be slid within the tube to vary the size of an internal chamber.

The present invention provides a smoking article comprising:

a first part comprising a source of smokable material; a second part having at least an end configured to be movable relative to the first part, and

wherein the second part comprises a filter; wherein the smoking article is configured such that the position of the first part relative to the second part determines a property of the filter of the smoking article.

Thus, the smoking article has a filter which can be configured by the user. The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a first embodiment of a smoking article;

Figure 2 is a cut-away side elevation view of the smoking article of Figure 1 in a retracted state;

Figure 3 is a cut-away side elevation view of the smoking article of Figure 1 in an extended state;

Figure 4 is a perspective view of a second embodiment of a smoking article according to the present invention, in a partially formed state;

Figure 5 is a cut-away side elevation view of a third embodiment of the smoking article;

Figure 6a is a schematic perspective view of a fourth embodiment of the smoking article, in a retracted state; Figure 6b is a schematic perspective view of the smoking article of figure 6a, in an extended state;

Figure 7a is a schematic side elevation view of a first embodiment of a filter configuration system in a smoking article, in a retracted state;

Figure 7b is a schematic side elevation view of the filter configuration system of figure 7a, in a partially extended state;

Figure 7c is a schematic side elevation view of the filter configuration system of figure 7a, in an extended state;

Figure 8a is a perspective view of the first embodiment of the filter configuration system of figure 7a, in a retracted state;

Figure 8b is a perspective view of the first embodiment of the filter configuration system of figure 7a, in an extended state;

Figure 9a is a schematic side elevation view of a second embodiment of a filter configuration system, in a retracted state;

Figure 9b is a schematic side elevation view of the second embodiment of filter configuration system, in a partially extended state;

Figure 9c is a schematic side elevation view of the second embodiment of filter configuration system, in an extended state;

Figure 10a is a perspective view of the second embodiment of the filter

configuration system of figure 9a, in a retracted state;

Figure 10b is a perspective view of the second embodiment of the filter

configuration system of figure 9c, in an extended state;

Figure 11 is a schematic side elevation view of the second embodiment of filter configuration system, in a retracted state;

Figure 12a is a schematic side elevation view of a third embodiment of filter configuration system, in a retracted state;

Figure 12b is a schematic side elevation view of the third embodiment of filter configuration system, in an extended state. Figures 1 to 3 show a first embodiment of a smoking article 10. The smoking article may be an article such as a cigarette, cigar or cigarillo. For convenience, these will be referred to as "smoking articles" in this specification. The smoking article 10 comprises a first part comprising a source of smokable material in the form of a tobacco rod 11, with an attached first filter section 12. The tobacco rod 11 and first filter section 12 are attached with a covering layer, preferably formed of tipping paper. A second part of the smoking article comprises a sleeve 13 in the form of a cylindrical tube extends around the circumference of the tobacco rod 11 and/or first filter section 12. The tobacco rod 11 and first filter section 12, are dimensioned to slide as a unit longitudinally within the sleeve 13. The tobacco rod 11 and first filter section 12 may be referred to as a tobacco unit.

A second filter section 14 is at a mouthpiece end of the sleeve 13, distal from the first filter section 12. The second filter section 14 is securely attached and fixed within the the sleeve 13. The first and/or second filter sections 12, 14 are preferably made of a conventional cellulose acetate tow.

A chamber 15 is defined in the sleeve 13 between the first filter section 12 and second filter section 14. The chamber 15 has a variable length, and hence volume, as the first filter section 12 slides axially within the cylindrical sleeve 13. The chamber 15 has a length varying from zero to a predetermined maximum length. Thus, an end of the sleeve 13 distal to the source of smokable material is movable relative to the source of smokable material.

Relative movement of the first and second parts, i.e. sleeve 13 and tobacco rod 11 beyond the maximum length is prevented by a restraining means, preferably abutting surfaces on or adjacent to the tobacco rod 11 and sleeve 13. In particular, the restraining means may comprise a first engaging surface extending radially inwardly from the sleeve 13, engagable with a second engaging surface extending radially outwardly from the tobacco unit. The second engaging surface may be provided by sheet material wrapped around the tobacco unit, and in particular, by material (e.g. tipping paper) connecting the tobacco rod and first filter.

Figure 2 shows the smoking article 10 in a retracted state, with the tobacco rod 11 and first filter section 12 moved up to the second filter section 13. The length of the chamber 15 has been reduced to zero. The smoking article 10 is at its shortest overall length. The smoking article 10 may be packaged in the retracted state prior to use. The smoking article 10 may be returned to the retracted state after use, once the tobacco rod 11 has been partially or fully combusted.

Figure 3 shows the smoking article 10 in an extended state, with the tobacco rod 11 and first filter section 12 moved as far as possible away from the second filter section 14. The length of the chamber 15 has been increased to its maximum. The smoking article 10 is at its longest length. The smoking article 10 may be in the extended state during use. The tobacco rod 11 and first filter section 12 are continuously positionable within the sleeve 13 to be in any partially extended position between the retracted and extended states.

Figure 4 shows a second embodiment of the smoking article 20. The smoking article 20 comprises a cylinder of tobacco 21 surrounded by, and attached to, a sleeve 23 to form a tobacco rod. The cylinder of tobacco 21 does not move relative to the sleeve 23. The sleeve 23 has a section 23a extending rearwardly of the tobacco 21. A filter 24 is longitudinally slidable within the sleeve section 23a. A chamber 25 is formed by the tubular section 23a, between the tobacco 21 and the filter 24.

The smoking article 20 functions in a similar manner to smoking article 10. Smoking article 20 differs in that the sleeve forming the chamber 25 is rigidly attached to the tobacco rod, not the mouthpiece filter 24. Smoking article 20 also differs by not having a filter attached directly to the tobacco 21. A further embodiment of the present invention may have only one of these features or differences.

Relative movement of the sleeve 23 and filter 24 beyond the maximum length is prevented by a restraining means. Preferably, the restraining means comprises first and second engaging surfaces on or adjacent to the sleeve 23a and filter 24 respectively.

Figure 5 shows a third embodiment of the smoking article 30. Smoking article 30 has a similar construction to the embodiment of Figures 1 to 3, having a tobacco rod 31 attached to a filter 32. The tobacco rod 31 and filter 32 are slidable within a sleeve 33 formed as a cylindrical tube. At the mouthpiece end of the sleeve 33 is a stain binder 36, instead of a second filter. The stain binder 36 may remove substances which can cause staining. A variable length chamber 35 is formed between the filter 32 and stain binder 36.

Figures 6a and 6b show a fourth embodiment of an extendable smoking article 40. The smoking article 40 comprises a tobacco rod (not shown) attached to a first filter section 42. A sleeve 43 is attached to the first filter section 42. At a distal end of the sleeve 43 is a second filter section 44, defining a mouthpiece end. A chamber 45 is defined in the sleeve 43, between the first and second filter sections 42, 44.

The sleeve 43 can fold as a concertina in order to vary the length of the sleeve 43 and chamber 45. The sleeve 43 has a plurality of sections of varying diameter, such that fold lines are formed around the circumference of the sleeve 43 at lines of maximum and minimum diameter.

In a retracted state shown in Figure 6a, the first and second filter sections 42,44 are urged together, such that the sleeve is compressed. The sleeve lines of the sleeve 43 increase in angle, and segments of the sleeve 43 between fold lines are orientated towards a plane perpendicular to the longitudinal axis of the smoking article. The chamber 45 has a relatively short length.

In an extended state shown in Figure 6b, the first and second filter sections 42,44 are urged apart, such that the fold lines of the sleeve 43 decrease in angle, and segments of the sleeve 43 between fold lines are orientated towards a plane parallel to the longitudinal axis of the smoking article. The chamber 45 has a relatively long length. The concertina sleeve 43 therefore allows the chamber 45 to vary in length without requiring parts sliding relative to each other. Thus, an end of the sleeve 43 distal to the source of smokable material is movable relative to the source of smokable material. As shown in Figure 6b, the concertina sleeve 43 also allows controlled bending of the smoking article 40. The sleeve 43 may be urged at an angle or perpendicular to the longitudinal axis, such that one or more fold lines of the sleeve 43 are not uniformly extended around the circumference. The variation in extension around the circumference of the sleeve 43 provides for bending of the sleeve 43. The longitudinal axis of the first filter section 42 is not co-axial with the longitudinal axis of the second filter section 44 when the sleeve 43 is bent. The tobacco rod and attached filter are described as connected by tipping paper. The tipping paper may be standard tipping paper, or a relatively thick recessed tipping paper, or a board type tipping paper. Alternatively, a tube formed of any material may attach the filter material to the source of smokable material. In particular, such a tube may be made of a plastics material, for example, a plastic made from corn starch. Alternatively, the tube may be made from a ceramic material. Alternatively, the tube may be formed from foil, metal or metallised paper.

The embodiments above have been described as having a filter section at the mouthpiece adjacent the tobacco rod. Alternatively, there may be no filter section connected to the tobacco rod.

One or more of the filter sections may be formed of a single segment of filter material or a plurality of segments. A filter section formed of a plurality of segments may comprise segments made of different materials or having different filtration properties. In particular, a filter section may comprise a standard segment of cellulose acetate tow and a further segment of filtration material including charcoal. Alternatively, the filter section may be a single segment incorporating charcoal.

The second filter may be shaped, preferably to aid draw strength or provide other benefits relating to sensation and staining pattern. The filter may be made from pressed, formed or extruded acetate. In a further embodiment of the smoking article, the chamber contains loose filtration material, retained by the second filter or suitable means preventing escape of the loose material. The loose filtration material is preferably granulated carbon, providing loose carbon particles in the chamber.

Figures 7 to 12b show three embodiments of smoking article filter configuration systems, providing for variations in the filter arrangement. In particular, these embodiments have a filter property which is determined by the position of the first part relative to the second part, i.e. the position of the sleeve relative to the source of smokable material. In particular, the filter property determined may be effective filter length, filter strength, or may be filter position within the sleeve. Any of the embodiments of the filter configuration systems may be used with any of the embodiments of smoking article described in Figures 1 to 6, unless otherwise stated. Figures 7a to 8b show a first embodiment of a filter configuration system in a smoking article 50. Smoking article 50 comprises a variable length chamber 55, substantially as described in any of the embodiments above. The smoking article 50 comprises a tobacco unit 51, which may comprise a tobacco rod and first filter as described with respect to Figures 1 to 3 or 5 to 6b, or only a tobacco rod as described with respect to Figure 4. The tobacco rod 51 is moveable relative to at least a mouthpiece end of the sleeve 53. The chamber 55 is defined between the tobacco unit 51 and a filter or stain binder 54. The filter or stain binder 54 will be referred to as filter 54. The filter 54 is connected to the sleeve 53 by a variable length assembly 58,59. The assembly 58,59 provides for longitudinal movement of the filter 54 relative to the sleeve 53. The assembly 58,59 also provides a seal between the filter 54 and mouthpiece end of the sleeve 53. The assembly 58,59 is preferably telescopic, and in particular, comprises first and second telescoping sections 58,59. The first telescoping section 58 is attached to an interior surface of the sleeve 53, adjacent the mouthpiece end. The first telescoping section 58 is in the form of a cylinder. The second telescoping section 59 slides within the first telescoping section 58. The second telescoping section 59 is a cylinder of smaller diameter than the first telescoping section 58.

The first and second telescoping sections 58,59 are provided with means to limit relative movement, and so maintain the second telescoping section 59 in attachment to the first telescoping section 58. The first telescoping section 58 comprises a radially inwardly extending flange adjacent to an end distal from the mouthpiece end. The second telescoping section 59 comprises a radially outwardly extending flange adjacent to an end proximal to the mouthpiece end. The flanges engage to retain the first and second telescoping sections 58, 59 together.

The filter 54 is slideable longitudinally within the second telescoping section 59. The second telescoping section 59 and filter 54 are provided with means to limit relative movement, and so maintain the filter 54 in attachment to the second telescoping section 59. The second telescoping section 59 comprises a radially inwardly extending flange adjacent to an end distal from the mouthpiece end. The filter 54 comprises a radially outwardly extending flange adjacent to an end proximal to the mouthpiece end. The flanges engage to retain the filter 54 and second telescoping section 59 together

The first and second telescoping sections 58, 59 are preferably formed of a permeable material. In a partially or fully extended state, smoke or air can pass through the first and second telescoping sections 58, 59, and bypass the filter 54. The air permeable material may be acetate, and may be formed around a mandrel with a relatively increased amount of plasticiser.

A flexible elongate substrate 57 is located in the chamber 55. The substrate 57 has a first end attached to the tobacco unit 51. The substrate 57 has a second end attached to the filter 54. The substrate 57 is preferably a string.

The tobacco unit 53 is movable away from the mouthpiece end of the sleeve 53, from a retracted state as shown in Figure 7a, to a partially extended state shown in Figure 7b, to an extended state shown in Figure 7c. In the embodiment shown, the sleeve 53 is a tube slideable around the tobacco unit 51.

The filter 54 is attached to the tobacco unit 51 by the substrate 57. The substrate 57 is slack when the smoking article is in the retracted state. As the smoking article is extended, the filter 54 is pulled by the substrate 57 away from the mouthpiece end of the sleeve 53. A recess 56 is created at the mouthpiece end of the sleeve 53 as the filter 54 is pulled by the tobacco unit 51. The recess 56 may provide for different characteristics of the smoking article in use, compared to a smoking article without such a recess 56. Thus, the property of filter position within the sleeve is

determined by relative position between the source of smokable material and sleeve.

Figure 7b shows that as the substrate 57 becomes taught, the filter 54 and second telescoping section 59 move together within the first telescoping section 58. Once the second telescoping section 59 reaches its maximum extent within the first telescoping section 59, the filter 54 slides telescopically from within the second telescoping section 59. Alternatively, the filter 54 may initially move within the second telescoping section 59, followed by movement of the second telescoping section 59 within the first telescoping section 58. Alternatively, the filter 54, first and second telescoping sections 58,59 may all slide simultaneously. When the filter 54 reaches its maximum longitudinal extent, the substrate 57 prevents further movement of the tobacco unit 51 relative to the sleeve 53.

Figure 8a shows the smoking article 50 in a retracted state. The first and second telescoping sections 58,59 and filter 54 are aligned with the mouthpiece end of the sleeve 53. Figure 8b shows the smoking article 50 in an extended state. The movement of the tobacco unit 51 has pulled the filter 54 away from the end of the sleeve, creating recess 56. Air may pass around or through the telescoping sections 58,59, providing an alternate flow path which may vary the effective characteristics of the filter.

Figures 9a to 11 show a second embodiment of a filter configuration system in a smoking article 70. The smoking article 70 comprises a tobacco unit 71 which comprises a tobacco rod and first filter 74 similar to the embodiment as described with respect to Figures 1 to 3 or 5 to 6b. The tobacco rod 71 is moveable relative to a sleeve 73. The smoking article 70 does not comprise a further filter which is longitudinally spaced from the second filter to form a chamber.

The smoking article 70 comprises a tobacco unit 71 comprising a filter 74. The filter 74 has a diameter which is smaller than the attached tobacco rod. The filter 74 is a single filter unit, rigidly coupled or attached to the tobacco rod. The sleeve 73 comprises an annular ring 77. The ring 77 may be made of a filter material, or may be made of a solid non-porous material. The ring 77 surrounds the filter 74, and preferably forms a snug fit around the filter 74.

Figure 9a shows the smoking article 70 in a retracted state. The filter 74 is wholly located within the ring 77. The ring 77 abuts against the tobacco rod. The effective length of the filter 74 is the whole length of the filter 74, since there is no alternate route between the tobacco rod and a mouthpiece end of the sleeve 73.

The sleeve 73 comprises ribs 79a which form part of an indexing mechanism. The indexing mechanism is described in more detail with respect to Figure 11.

Figure 9b shows the smoking article 70 in a partially extended state. The filter 74 extends partially out of the ring 77. An annular passageway 78 is defined around the part of the filter 74 extending longitudinally out from the ring 77. The annular passageway 78 allows free flow of material. A recess 76 is formed at the mouthpiece end of the sleeve 77. The effective length of the filter 74 is shorter than in the retracted state. There is an alternate route from the tobacco rod to the end of the sleeve through passageway 78, which bypasses part of the filter 74. Air generally flows along the whole length of passageway 78 before entering the filter 74, and passing into the recess 76.

Figure 9c shows the smoking article 70 in an extended state. The filter 74 has a majority of its length extending out of the ring 77. A part of the filter 74 is still maintained within the ring 77. The passageway 78 and recess 76 both have a maximum length. The effective length of the filter 74 is at its shortest, since the passageway 78 provides an alternate route bypassing the majority of filter 74. The smoking article 70 provides a filter 74 having a variable effective length.

Longitudinal movement of the tobacco unit 71 within the sleeve 73 varies the length of a passageway 78 surrounding the filter 74. A variation in the length of the smoking article 70 controls the effective length of filter 74, which is controllable by a user. The effective length of the filter 74 determines the strength of the smoking article 70.

Figures 10a and 10b show the smoking article in a retracted state and extended state respectively. In the retracted state, the filter 74 extends to the end of the smoking article. In the extended state, the filter 74 has moved with respect to the sleeve to form a recess 76.

The smoking article 70 comprises a filter having a variable effective length. The filter section 74 is positionable within a reduced diameter section, such that the part within the reduced diameter section contributes to the effective length of the filter. The filter section is movable into a larger diameter section, the part in the larger diameter section does not contribute to the effective filter length. The movement of the filter sections from the reduced diameter section to the larger diameter section is coupled to the extension of the smoking article 70. The reduced diameter section is adjacent the mouthpiece end of the sleeve, and the larger diameter section is between the reduced diameter section and tobacco unit. The effective length is altered (reduced) by extending the smoking article 70. Thus, the property of effective filter length is determined by relative position between the source of smokable material and sleeve. A user can control the strength of the smoking article 70 by selecting the extension, and hence the effective filter length.

Figure 11 shows an indexing mechanism of the smoking article. The indexing mechanism allows selection of a predetermined longitudinal extension of the smoking article. The sleeve 73 is provided with a plurality of ribs 79a. Preferably, the sleeve comprises three ribs 79a. The ribs 79a may be annular, or may extend over only part of the circumference of the sleeve 73. The ribs 79a each define a depression on an interior surface of the sleeve 73.

The tobacco unit 71 is provided with a protrusion 79b. The protrusion 79b may extend around the circumference of the tobacco unit, or only over part of the circumference. The protrusion 79b is configured to engage in a depression of a rib 79a to form an indexing mechanism. The protrusion 79b may engage in a depression at three extensions of the smoking article 70 corresponding to the retracted state, partially extended state and extended state as shown.

The protrusion 79b and/or sleeve 73 is resiliently deformable to allow the protrusion 79b to move between depressions of the ribs 79a. The protrusion 79b extends into a selected depression, inhibiting further movement and indicating an indexed position has been reached.

The ribs 79a and/ or protrusion 79b may be provided with markings to indicate the position of the protrusion 79b, and hence the strength of the smoking article. In particular, the ribs 79a may each define a window, and the protrusion may have a coloured marking visible through the corresponding window.

It will be appreciated that other types of indexing mechanism may be used, or the smoking article 70 may not have an indexing mechanism. In particular, the indexing mechanism may comprise a plurality of ribs 79a and a plurality of protrusions 79b, or one rib 79a and a plurality of protrusions 79b. Alternatively, the protrusion(s) 79b may be formed on the interior surface of the sleeve, and the tobacco unit provided with one or more depressions.

Figures 12a and 12b show a third embodiment of a filter configuration system in a smoking article 80. Smoking article 80 comprises a variable length chamber 85, substantially as described in any of the embodiments above. The smoking article 80 comprises a tobacco unit 81, which may comprise a tobacco rod and first filter as described with respect to Figures 1 to 3 or 5 to 6b, or only a tobacco rod as described with respect to Figure 4. The tobacco rod 81 is moveable relative to a mouthpiece end of the sleeve 83. The chamber 85 is defined between the tobacco unit 81 and a filter assembly 84.

The filter 84 comprises a plurality of filter segments 89a, 89b, 89c. The filter segments 89a, 89b, 89c are connected by an elongate flexible substrate 88, preferably in the form of a string. The flexible substrate 88 is connected to the tobacco unit 81. A part of the flexible substrate 88 extends between the filter segments 89a, 89b, 89c, such that the filter segments 89a, 89b, 89c are separate from each other in a longitudinal direction and a space is defined between the filter segments 89a, 89b, 89c. The segments are attached together and coupled to the source of smokable material by a flexible elongate substrate.

The sleeve 83 further comprises an annular ring 87, on an interior surface adjacent the mouthpiece end. The ring 87 may be made of a filter material, or may be made of a solid non-porous material. The ring 87 surrounds the filter assembly 84, and an interior surface of the ring 87 forms a snug fit around the filter assembly 84.

The chamber 85 has a larger diameter than the interior surface of the ring 87. The chamber 85 therefore has a larger diameter than the filter segments 89a, 89b, 9c.

Figure 12a shows the smoking article 80 in a retracted or partially extended state. The filter segments 89a, 89b, 89c are all located within the ring 87. The effective length of the filter 84 is therefore the combined length of all the filter segments 89a, 89b, 89c forming the filter 84. The substrate 88 is preferably taut between the filter segments 89a, 89b, 89c, such that the filter segments 89a, 89b, 89c are spaced apart within the ring 87. Alternatively, the filter segments 89a, 89b, 89c may initially abut each other within the ring 87. The substrate 88 connecting the filter segments 89a, 89b, 89c may be slack. Figure 12b shows the smoking article 80 in a further extended state. The tobacco unit 81 has slid longitudinally away from the mouthpiece end of the sleeve 83. The substrate 88 connected to the tobacco unit 81 has pulled the filter segments 89a, 89b, 89c forwardly, away from the mouthpiece end of the sleeve 83. A filter section 89a proximal to the tobacco unit 89a is located outside of the ring 87, in the chamber 85. The filter sections 89b, 89c are still in the ring 87.

The effective length of the filter 84 is the length of the filter sections 89b, 89c in the ring 87. The filter section 89a outside of the ring 87 does not contribute to the effective filter length, since air can flow around the filter section 89a in the chamber 85. The taut substrate 88 suspends the filter section 89a away from the walls of the chamber, forming a passageway around the circumference of the filter section 89a.

The smoking article 80 can be further extended such that only one filter section 89c is within the ring 87. The effective filter length is only the length of the one filter section 89c. The smoking article may optionally be further extended such that none of the filter segments 89a, 89b, 89c are within the ring 87, and there is no effective filter 84. The smoking article 80 comprises a filter having a variable effective length. Discrete filter segments 89a,89b,89c are positionable within a reduced diameter section, such that the filter sections contribute to the effective length. The filter sections are movable into a larger diameter section such that the filter sections do not contribute to the effective filter length. The movement of the filter sections from the reduced diameter section to the larger diameter section is coupled to the extension of the smoking article 80. The reduced diameter section is adjacent the mouthpiece end of the sleeve, and the larger diameter section is between the reduced diameter section and tobacco unit. The effective length is altered (reduced) by extending the smoking article 80.

Thus, the property of effective filter length is determined by relative position between the source of smokable material and sleeve. A user can control the strength of the smoking article 80 by selecting the extension, and hence the effective filter length.

The term "diameter" is used for the lateral extent of features of the embodiments of smoking article. Preferably, the smoking article has a circular cross-section, for which the term "diameter" is appropriate. Alternatively, features of a smoking article according to the invention may have a non-circular cross-section, for example, elliptical or square. References to "diameter" should be interpreted as lateral extent as appropriate.

The passageway described above may extend around the whole circumference of the filter section or segment, or only around part of the circumference.

A smoking article according to any embodiment may further comprise a source of flavouring. The flavouring may be releasable as the first part is moved relative to the second part, or may be releasable by a separate action. The source of flavouring may provide any flavour, for example, menthol. The source of flavouring may be in a filter. The smoking article has a filter property (in particular, effective filter length) which is variable. The level or strength of the flavouring may vary as a result of the filter property being varied.

In use, a smoking article according to any of the embodiments described is preferably packaged in a retracted state. In order to use, the user extends the smoking article by urging apart the sleeve and tobacco units in at least a longitudinal direction. The user may light the tobacco in a conventional manner. The length of the chamber and/ or extension may be used to vary the properties of the smoking article.

In order to extinguish the smoking article, the user may press the lit tobacco end against any suitable extinguishing surface. When the user holds the sleeve to extinguish the cigarette, the tobacco unit will be urged into the sleeve along the longitudinal axis until the remaining tobacco unit is covered by the sleeve. The burnt tobacco rod is therefore not visible in a side view of the extinguished smoking article.

Any of the features of any embodiment may be combined with any of the features of any other embodiment. In particular, any of the embodiments of smoking article may or may not have a filter section adjoining the cylinder of tobacco.

The smoking article has been described as extendable. Alternatively, the smoking article may have a fixed length. The first part may only be rotatable relative to the second part. The filter property may be selected by rotation of the sleeve without changing the length of the smoking article.

Claims

1. A smoking article comprising:

a first part comprising a source of smokable material;

a second part having at least an end configured to be movable relative to the first part, and

wherein the second part comprises a filter;

wherein the smoking article is configured such that the position of the first part relative to the second part determines a property of the filter of the smoking article.

2. The smoking article as claimed in claim 1 wherein the second part comprises a sleeve and the filter is coupled to the sleeve, or, the first part further comprises a sleeve and the second part comprises said filter moveable relative to the sleeve.

3. The smoking article as claimed in claim 1 or 2 wherein the smoking article is an extendable smoking article, and the second part has a distal end configured to move longitudinally relative to the first part.

4. The smoking article as claimed in claim 1, 2 or 3 wherein an effective length of the filter is determined by the position of the first part relative to the second part.

5. The smoking article as claimed in claim 4 wherein the smoking article defines a passageway providing for air flow around a selected part of the filter, said selected part not contributing to the effective length of the filter.

6. The smoking article as claimed in claims 2 and 5 wherein the sleeve defines a first section having a first cross-sectional area, and a second section having a second cross-sectional area larger than the first cross-sectional area,

wherein the filter extending in the first section fits closely in the first cross-sectional area, and the passageway is formed around a part of the filter in the second section.

7. The smoking article as claimed in claim 6 wherein the first section has a length substantially the same as the length of the filter.

8. The smoking article as claimed in any one of claims 1 to 4 wherein the filter is rigidly coupled to the source of smokable material.

9. The smoking article as claimed in any one of claims 1 to 4 wherein the filter comprises a plurality of separable filter segments.

10. The smoking article as claimed in claim 9 wherein the filter segments are attached together in a spaced apart configuration by a flexible elongate substrate.

11. The smoking article as claimed in any one of claims 1 to 4 wherein the filter is attached to the second part by an extendable telescopic assembly.

12. The smoking article as claimed in claim 11 wherein the extendable telescopic assembly comprises telescopic sections formed of a permeable material.

13. The smoking article as claimed in any one of claims 9 to 12 wherein the filter is coupled to the first part such that the filter is movable with the first part, over at least a part of a range of movement of the first part relative to the second part.

14. The smoking article as claimed in any one of claims 9 to 12 wherein the filter is coupled to the first part with an elongate flexible substrate.

15. The smoking article as claimed in any one of the preceding claims wherein the smoking article comprises an indexing mechanism to releasably secure the first part and second part in a plurality of predetermined relative positions.

16. The smoking article as claimed in claim 2 wherein the second part comprises a sleeve, and the sleeve is formed as a cylinder, and is slidable longitudinally around the source of smokable material.

17. The smoking article as claimed claim 2 wherein the second part comprises a sleeve, and the sleeve is formed as a concertina.

18. The smoking article as claimed in any one of the preceding claims further comprising a source of flavouring, wherein a level of flavouring is dependent on a level of filtration of the smoking article.

19. A smoking article as hereinbefore described and shown with reference to any one of the accompanying drawings.