EP0102247B1

EP0102247B1 - Tipping assembly for an elongate smoking article

Info

Publication number: EP0102247B1
Application number: EP83304993A
Authority: EP
Inventors: Christopher Ralph Bale; Beresford Roy Gill; David Wyn Bassett
Original assignee: Imperial Tobacco Ltd United Kingdom
Current assignee: Imperial Tobacco Ltd
Priority date: 1982-09-01
Filing date: 1983-08-30
Publication date: 1987-10-28
Also published as: GB2126073A; DE3374164D1; GB8323244D0; EP0102247A1; GB2126073B

Description

This invention relates to a tipping assembly for an elongate smoking article, such as a cigarette.
Traditional methods of achieving low tar yields from a cigarette in combination with high nicotine levels and low carbon monoxide levels use high levels of filtration and ventilation but have the disadvantages of a high pressure drop perceived by the smoker and a reduced subjective response compared with the pressure drop and subjective response associated with a non-filter cigarette.
It is an object of the present invention to provide a tipping assembly that substantially reduces the above disadvantages.
The present invention concerns a tipping assembly for an elongate smoking article, the assembly comprising an open-ended tube provided with a plurality of apertures spaced round the circumference of the tube, thereby defining two sections of the tube and providing communication between the inside and the outside of the tube, and a tipping wrapper surrounding the tube, a portion of the tipping wrapper overlying the apertures being adapted to permit gas flow both through the apertures and said portion and to offer greater resistance to the gas flow than is provided by the apertures alone. GB-A-2088191 discloses a tipping assembly of this general type in which the tube is formed of a sheet of non-porous wrapping material, and the apertures are small openings in the sheet.
The tipping assembly of the present invention is characterised in that the two sections of the tube are axially spaced apart from each other and there is provided a plurality of means to hold the sections fixed relative to each other each of the plurality of spacing means defining the separation between one of the plurality of apertures and its adjacent neighbour.
The invention will now be described by way of example only with reference to the accompanying non-scaled diagrammatic drawings in which:

Fig. 1 is a longitudinal section through a first embodiment of a tipping assembly according to the invention, in combination with a tobacco rod;
Fig. 2 is an exploded perspective view of the tipping assembly of Fig. 1;
Fig. 3 is a longitudinal section through a second embodiment of a tipping assembly according to the invention, in combination with a tobacco rod;
Fig. 4 is an exploded perspective view of the tipping assembly of Fig. 3;
Fig. 5 is a lateral section through the tipping assemblies of Figs. 1 and 3 taken at line IX-IX;
Fig. 6 is an exploded perspective view of a third embodiment of a tipping assembly according to the invention; and
Fig. 7 is an end view of the tipping assembly of Fig. 6 taken in the direction of arrow XI.

Referring to Figs. 1, 2 and 5 there is shown a first embodiment of the invention comprising a cylindrical tobacco rod 110 enwrapped in cigarette paper 115, and a tipping assembly indicated generally at 100. The tipping assembly comprises a cellulose acetate filter rod 200 of conventional construction and in abutment therewith an open-ended polyethylene tube 130 wrapped in tipping paper 120 by means of which the tube and filter rod are attached to the tobacco rod.
The tube 130 is divided into two tubular sections 131 and 132 by three apertures 160 extending round the circumference of the tube 130 and separated by three narrow integral webs 161 of the material of the tubing which hold the two sections 131, 132 in a fixed relationship apart from each other.
The tipping paper 120 is provided with a circumferential series of perforations 170 overlying the apertures 160. Typically, the perforations 170 are 0.8 mm diameter or less, considerably smaller than the width of the apertures 160, which is about 2 mm.
Referring to Figs. 3, 4 and 5 there is shown a second embodiment comprising a tobacco rod and tipping assembly similar to that of Figs. 3, 4 and 5, identical features retaining the same numbering, and further provided with a plug 140 of cellulose acetate filter material at the mouth end of the tube. In this embodiment the tube 130 is substantially shorter than the tube of Figs. 2 and 3.
Referring to Figs. 6 and 7 there is shown a third embodiment similar to that of Figs. 1 and 2 except that the separated sections 131, 132 of the tube 130 are held in a fixed relationship to each other not by integral webs but by rectangular vanes 180 of polyethylene extending longitudinally within the tube 130 from one section to the other and radially outwards from the longitudinal axis of the tube to a distance at least equal to the internal radius of the tube.
In further embodiments, not illustrated, any of the previously described embodiments may be modified by the incorporation of a sheet of porous plug wrap material (of typical porosity 200-1600 Filtrona K units) between the tube and the tipping paper.
The tube 130 may be divided into its sections 131,132 by a number of apertures 160 other than three together with the respective number of webs 161 in order to suit specific smoking requirements. The tube may be filled partly or wholly with highly porous material such as cellulose acetate in the sections 131 or 132. For instance, the filter rod 200 may at least in part occupy section 131.
The tipping assembly of the invention shows that it is possible to achieve low tar yields with high nicotine, low carbon monoxide, and acceptable smoking panel ratings, compared with conventional filters which utilise high levels both of filtration and dilution.
Perforations in the tipping wrapper may be provided by a large number of small perforations or by a small number of relatively large perforations.
The tipping wrapper may alternatively be adapted to permit gas flow through the apertures in the tube by providing a tipping wrapper having a very high porosity rather than by providing perforations.
The tube may be made of impervious material other than polyethylene, such as cardboard.
Other shapes, sizes, positions, and numbers of apertures in the tube may be contemplated in further embodiments of the invention.
For cigarettes embodying the invention, the smoke nicotine level can be high, and the carbon monoxide content and the CO/PM (carbon mono- xide/particulate material) ratio of the smoke can be remarkably low.

Claims

1. A tipping assembly (100) for an elongate smoking article, the assembly comprising an open-ended tube (130) provided with a plurality of apertures (160) spaced round the circumference of the tube, thereby defining two sections (131, 132) of the tube and providing communication between the inside and the outside of the tube, and a tipping wrapper (120) surrounding the tube, a portion of the tipping wrapper (120) overlying the apertures (160) being adapted (170) to permit gas flow both through the apertures (160) and said portion and to offer greater resistance to the gas flow than is provided by the apertures (160) alone, characterised in that the two sections (131, 132) of the tube are axially spaced apart from each other and there is provided a plurality of spacing means (161; 180) to hold the sections fixed relative to each other, each of the plurality of spacing means defining the separation between one of the plurality of apertures (160) and its adjacent neighbour.

2. An assembly as claimed in claim 1 wherein the holding means is provided by a plurality of webs (161) of tube material integral with and oriented parallel to the axis of the tube, the width of each web (161) being substantially less than that of an adjacent aperture (160).

3. An assembly as claimed in claim 2 wherein the apertures (160) are provided by slots the major axes of which are parallel to the longitudinal axis of the tube (130).

4. An assembly as claimed in claim 1 wherein the holding means is provided by a plurality of rectangular vanes (180) extending longitudinally within the tube (130) from one section (131) to the other (132) and radially outwards from the longitudinal axis of the tube to a distance at least equal to the internal radius of the tube (130) thereby to define the apertures (160).

5. An assembly as claimed in any preceding claim wherein said portion of the tipping wrapper (120) is adapted to permit gas flow therethrough by means of perforations (170), the perforations being substantially smaller than the apertures (160).

6. An assembly as claimed in any preceding claim wherein there is provided a sheet of porous plug wrap material between the tube (130) and the tipping wrapper (120) at least in the region overlying said apertures (160).