CIGARETTES AND THEIR CONSTRUCTION

Abstract

A cigarette is provided with the tobacco column portion adjacent the filter assembly encased by a heat shrink material whereby as the burn approaches the butt the heat shrink material begins to contract radially and compress the encased tobacco column restricting the air flow therethrough. This reduces the diameter of burning column adjacent the filter assembly and thus extinguishes or at least confines the remaining tobacco in the cigarette.

Claims

1. A tipping paper wrap which may be fed from a roll and wound onto a column assembly including a tobacco column and a co-axially juxtaposed filter, the tobacco column having a butt portion extending axially from the filter, the wrap comprising: a band of tipping paper formed to wrap about the filter, and a band of heat shrink material protruding from one edge of the tipping paper and which on application to said respective column assembly extends beyond the junction between the filter and the juxtaposed tobacco column to form an encasing heat shrink layer about the butt portion of the tobacco column.

2. The tipping paper wrap as claimed in claim 1, wherein the band of heat shrink material is formed to extend along a minor portion of the length of the tobacco column.

3. The tipping paper wrap as claimed in claim 2, wherein the band of heat shrink material overlaps the adjacent edge portion of the filter paper and extends therefrom for a distance of between 5 mm and 10 mm.

4. The tipping paper wrap for simultaneous application to a pair of oppositely arranged respective column assemblies each including a tobacco column and a filter arranged with their respective filters in substantially co-axial abutting relationship, said wrap having one side portion forming a tipping paper wrap as claimed in claim 1 for application to one said column assembly and an opposite side portion forming a tipping paper wrap for application to the other said column assembly.

5. A method of joining a tobacco column to a co-axially juxtaposed filter including providing a tipping paper wrap as claimed in claim 1 and winding the tipping paper wrap onto the juxtaposed tobacco column and filter to form an encasing layer of heat shrink material which spans the joint between the tobacco column and the filter to join them together.

6. The method as claimed in claim 5, wherein the coaxially juxtaposed tobacco column and filter are rotated about their common longitudinal axes to wind the tipping paper wrap thereabout.

7. The method as claimed in claim 5, wherein the tipping paper wrap is simultaneously wound onto a pair of tobacco columns and their respective filers arranged in a coaxial array with their filters adjoining one another.

8. The method of joining a tobacco column to a co-axially juxtaposed filter comprising providing a tipping paper wrap as claimed in claim 1 and winding the tipping paper wrap onto the juxtaposed tobacco column and filter to join them together and to form an encasing layer of heat shrink material about the butt of the tobacco column.

9. A cigarette made in accordance with the method of claim 5.

10. A tipping wrap for use in the manufacture of cigarettes, comprising: central band of tipping paper having a width which can span a pair of abutting coaxially aligned filter assemblies; and a pair of opposed side bands of heat shrinkable wrapping material affixed to opposite sides of the central band of tipping paper; wherein on application to the coaxially aligned filter assemblies the side bands of heat shrinkable wrapping material extend beyond the junction between the filter and a juxtaposed tobacco column to form an encasing heat shrink layer about the butt portion of the tobacco column.

11. The tipping wrap of claim 10, wherein pair of opposed side bands overlap and are glued to the central band of tipping paper.

12. The tipping wrap of claim 11, wherein pair of opposed side bands extends a distance of between 5 mm and 10 mm beyond the sides of the central band of tipping paper.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order that this invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate typical embodiments of cigarettes made by the methods and or utilizing the components broadly described above, and wherein:

[0025] FIG. 1 is a perspective view of a cigarette formed according to one aspect of this invention;

[0026] FIG. 2 illustrates a tipping paper made in accordance with one aspect of this invention;

[0027] FIG. 3 illustrates the configuration of a discarded butt of a cigarette made in accordance with the embodiment of FIG. 1;

[0028] FIG. 4 is a perspective view of a cigarette formed according to another aspect of this invention, and

[0029] FIG. 5 illustrates an alternate form of tipping paper and method of its installation onto opposed tobacco columns and filters.

DETAILED DESCRIPTION

[0030] Referring to FIG. 1 it will be seen that a cigarette 10 includes a wrapped tobacco column 11 secured to a filter assembly 12 by tipping paper 14 which is wrapped around the assembled filter assembly 12 and tobacco column 11 during a typical manufacturing process to join them together and to provide the filter wrap or tipping paper a smoker's lips contact.

[0031] According to this invention, in this embodiment the tipping wrap 18, as illustrated in FIG. 2, includes a conventional tipping paper portion 15 and an adjoining wrapping portion 16 formed from heat shrinkable material which when wrapped upon itself about the tobacco column 11 forms an encasing tube which shrinks upon the application of heat thereto to a smaller diameter tube 19, as illustrated in FIG. 3, surrounding the unburnt tobacco and/or the ash from the burnt tobacco. For this purpose the heat shrinkable material is applied to the tipping paper with its major shrinking axis extending parallel to its junction with the tipping paper 15.

[0032] The width of the tipping paper portion 15 is suitably about the same as the length of the filter assembly 12 while the shrinkable wrapping portion 16 is sufficiently wide so as to extend along the butt portion 17 of a tobacco column which is normally discarded with the filter assembly 12. For a cigarette having a tobacco column diameter in the order of 7 mm to 9 mm the shrinkable wrapping portion 16 suitably has a length of between 6 mm to 12 mm. Suitably the shrinkable wrapping portion 16 is transparent but it may be of any desired color and it may be printed with information desired to be displayed by the cigarette manufacturer.

[0033] As illustrated in FIG. 2, the tipping wrap 18 is supplied as a continuous roll 18 which may be wrapped around a former if desired or otherwise stored to enable it to be used as a substitute for the existing tipping paper so as to minimize disruption to the manufacturing process in order to incorporate aspects of this invention into the manufacture of cigarettes.

[0034] When a cigarette 10 according to this embodiment is smoked down to its butt 17, the core heat generated by the burning tobacco will cause the encasing heat shrinkable wrap of the wrapping portion 16 to shrink as a contracting tube 19, reducing the area of the open end 20 thereof, as illustrated in FIG. 3, through which air and pollutants may be drawn through the filter assembly 12 by the smoker.

[0035] Depending on the selection of the properties of the heat shrinkable material utilized in the wrapping portion 16, the reacting heat shrinkable material will either render the cigarette unpleasant for further smoking such that much of the pollutants contained in a tobacco column will not be inhaled, or the remaining tobacco burning with a diminished supply of oxygen or extinguished as a result of sufficient compaction of the tobacco within the shrunk tube 19 will be contained within the wrap 16 and rendered relatively harmless. Thus if discarded carelessly whilst alight into combustible material such as grass the butt should not cause a fire as many combustible materials have to be heated to an elevated temperature before combustion occurs. This requires the butt to remain alight for a relatively long period which should not occur in a cigarette according to this invention.

[0036] Further as illustrated in FIG. 3, a still burning butt in this form when rested on its side upon a flat surface such as a table will be disposed with its burning end 22 elevated above the table so that it will not heat the surface sufficiently to burn it.

[0037] In the cigarette 24 illustrated in FIG. 4, the heat shrinkable encasement 25 of the tobacco column 26 extends further along the column than in the cigarette illustrated in FIG. 1. Furthermore, this encasing tube 25 is graduated so that an outer portion, such as the end portion 27, will not shrink as much as the adjacent portion 28 whereby during smoking, the encasing tube 25 will progressively reduce in diameter to constrict and contain the burnt and burning tobacco column and if desired eventually extinguish the butt portion by sufficient compression of the tobacco column to effectively prevent the through flow of air necessary to maintain burning.

[0038] The encasing tube 25 could extend along a major or minor portion of the tobacco column depending on the effect to be achieved and the specification of the heat shrinkable material used and of course the encasement could be applied as a formed tube to a manufactured cigarette or it could be in the form of a band which could be positioned during manufacture or by a smoker at a selected position along the length of the column to extinguish the tobacco at that position.

[0039] In the FIG. 5 embodiment illustrated, a tipping wrap 30 has a central band of tipping paper 31 and opposed side bands 32, 33 of shrinkable wrapping material each arranged with their respective major shrink direction extending longitudinally along the tipping wrap 30. The central band of tipping paper is between 30 mm and 50 mm wide so that it may span a pair of filter assemblies 34 arranged in end to end abutting relationship.

[0040] The bands of shrinkable wrapping material 32, 33 are each approximately 10 mm wide and overlap the adjacent edges of the band of tipping paper 31 by about 2 mm and are glued thereto along the overlap zone 37 by a warm set gum. Thus in a manufactured cigarette the formed shrinkable tubes 36 extend about 8 mm along the butt 38 of the tobacco column 39.

[0041] According to this method of the invention, opposed pairs of formed tobacco columns 39 and filter assemblies 34 are arranged co-axially in abutting relationship, as illustrated, and the tipping wrap 30 is wound onto the assembled tobacco columns 39 and filter assemblies 34. After wrapping, the formed cigarettes are separated by slitting the wrap 30 between the opposed filter assemblies 34. If desired the tipping wrap could be formed as a broad composite sheet formed of multiple bands of tipping wraps as illustrated in FIG. 5 arranged in side by side relationship across the sheet or otherwise as required to suit the manufacturing process.

[0042] It will of course be understood that the above has been given by way of illustrative example only and that all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is defined in the appended claims.