GB2082042A - Cigarette holders with filters - Google Patents

Abstract

A tobacco smoke filtering device having the appearance of an extension of the tobacco article to be smoked so as to avoid appearing to be a filter. Filtering baffles and apertures being provided between the tobacco article holdings part and the mouth piece. <IMAGE>

Description

SPECIFICATION Tobacco smoke filter The present invention relates to a smoke filtering device which is generally simple in construction relative to known cigarette filtering devices.

It is generally agreed by health authorities that the smoking of tobacco products is deleterious to human health. Numerous filters have been-proposed to extract from the tobacco smoke stream deleterious matter such as particulate matter entrained in the smoke stream and condensable materials such as tars. Such filtering devices are generally of two types, the first type being formed integrally with a cigarette and forming a "tip" thereon and the second type being ofthe "cigarette holder type". The latter type has generally contained a replaceable filter element which can be removed when it becomes filled with filtered material. Such cigarette holder type filtering devices have had the disadvantage of being relatively expensive and of low consumer acceptance due to the generally unaesthetic appearance of the filter element when it is ready for replacement.In addition the length and weight of conventional cigarette holder type filtering devices have limited their user acceptance.

The present invention consists in a tobacco smoke filtering device for use with cigarettes, comprising a cylindrical tubular receptacle to receive an end of a cigarette, a mouth-piece and tobacco smoke filtering means disposed between the receptacle and the mouth-piece, the arrangement being characterised in that the mouth-piece is a thin-walled tubular element of substantially uniform cross-sectional shape and area throughout its legnth.

In a preferred embodiment of the invention the end of the mouth-piece distal to the tubular receptacle is provided with an end wall in which are formed a number of apertures. The apertures are preferably spaced inwardly from the tubular wall such that smoke condensate deposited within the mouthpiece is restrained against contact with the smoker's tongue or mouth. The mouth-piece is preferably of circular cross-sectional shape, however, other cross-sectional shapes could be used particularly those approximating a circle. The mouth-piece is preferably of a cross-sectional area substantially similar to that of a conventional cigarette in order that the oral sensations provided by the mouth-piece approximate those of a cigarette.

The tobacco smoke filtering means disposed between the receptacle and the mouth-piece may be of any conventional type such as juxtaposed orifice and baffle plate means or a filter pad. These filtering means may be formed integrally with the tobacco smoke filtering device or may be replaceable.

In another aspect the present invention consists in a tobacco smoke filtering device comprising a tubular receptacle adapted to receive a tobacco smoke source, the receptacle having at one end a tubular extension, there being fixedly disposed within the receptacle, and/orthe extension, orifice means to constrict the area of flow of the smoke stream and to thereby accelerate the smoke stream, and baffle means arranged to be impinged upon by the accelerated smoke stream such that tar and other substances are deposited on the baffle means; and a mouth piece which is disposed about the extension and which projects beyond the extension away from the receptacle.

While the tobacco smoke filtering device according to this second aspect of the invention is primarily adapted for use with cigarettes it will be apparent to those skilled in the art that it could be adapted for use with a pipe or similar smoking apparatus. The receptacle is preferably cylindrical and has an internal diameter substantially equal to the external diameter of a cigarette.

The tubular extension of the receptacle is preferably formed at its end adjacent the receptacle with a portion of increased diameter adapted to receive a pair of metal discs constituting the orifice means and the baffle means. The orifice means and the baffle means are preferably held in place within the extension by being a force fit within the region of enlarged diameter of the extension. The end of the extension distal to the receptacle is preferably provided with an annular end wall coaxial with the extension. The aperture defined by this annular end wall most preferably is surrounded by a short tube extending inwardly into the extension and lying coaxially with the extension. The annular end wall and the inwardly directed tube serve to prevent tars and particulate matter trapped by the baffle means from flowing through the extension into the mouth piece.The discs may be conveniently formed from a suitable metal or synthetic plastics material.

The orifice means and baffle means in this aspect of the invention preferably comprise a pair of metal or plastic discs juxtaposed in face to face arrangement. The orifice means preferably has a pair of apertures in alignment across the diameter of the disc. The metal disc comprising the baffle means preferably includes a central, substantially circular, zone which lies in a plane parallel to the remainder of the disc but spaced slightly from it, in a direction away from the orifice means. The central zone being connected to the remainder of the disc by a pair of diametrically opposed tabs formed integrally with the central zone and the remainder of the disc. This arrangement defines a pair of arcuate apertures between the central zone and the remainder of the disc.The smoke stream which is accelerated on passing through the orifice means then impinges on the central zone of the baffle means such that some of the particulate matter in the gas stream is caused to adhere to the baffle plate and such that tar particles caused to condense in the cooling stream will also be entrained. The gas stream thereafterturns through 90 and travels laterally through the arcuate apertures into the extension of the receptacle.

The orifice means and the baffle means are so fixed in the receptacle andlor the tubular extension thereofthatthey are irremovable in the normal course of use. The simplification of the smoke filtering device according to this invention, and the consequent reduction in weight, necessitate the essentially integral form of construction as distinct from.

the situation in which a separate and removable fil tering cartridge is contained within an outer housing constituting the mouthpiece and the cigarette receptacle.

The present invention still further consists in a cigarette filter comprising a tubular cigarette receiving receptacle having an end wall formed integrally therewith, a tubular expansion chamber having an end wall formed integrally therewith, means to maintain the receptacle and the chamber in coaxial relationship with the end walls thereof in juxtaposition, and a tubular mouth piece coaxial with the receptacle and the chamber and surrounding the chamber over at least part of its length, a hole or holes extending through the end wall of the receptacle parallel to the axis thereof, the cross sectional area of the hole or of all of the holes being substantially smaller than the cross sectional area of the receptacle, the end wall ofthe expansion chamber including a baffle plate lying in a plane at right ang les to the axis of the hole, or the parallel axes of the holes and spaced slightly therefrom, and an aperture or apertures being formed in the end wall of the chamber adjacent the baffle plate which aperture or apertures have a cross sectional area substantially greater than that of the hole or holes in the end wall of the receptacle.

The component parts of the cigarette filter according to this third aspect of the present invention are preferably formed by injection moulding suitable synthetic plastics materials. The cigarette receptacle and the expansion chamber are preferably formed of a transparent or translucent material, whereas the mouthpiece is preferably formed of an opaque material.

The means to connect together the receptacle and the chamber preferably comprises a tubular extension of either of the receptacle or the chamber which receives the adjacent end of the other member in a sliding fit. The mouthpiece preferably slides over the chamber up until it abuts with an end of the abovementioned tubular extension. In another embodiment of the invention the mouthpiece may overlap the junction between the receptacle and the chamber and itself hold those two members in juxtaposition and in axial alignment.

The end walls of the receptacle and the chamber may actually abut over a substantial proportion of their area. In some embodiments of the invention, however, they may be juxtaposed with a small spacing therebetween. Preferably the end walls of the two members will lie in parallel planes. The end wall ofthe receptacle will normally be provided with one or two holes. If desired each hole may taper over at least part of its length, in a direction towards the mouthpiece. It is preferred that this tapering extends over only a part of the length of each hole such that the hole has a cylindrical internal wall immediateiy adjacent the face of the wall proximal to the chamber.

The baffle plate is preferably offset out of the plane of the end wall of the chamber and is connected thereto by a plurality of narrow straps. This arrangement allows a stream of smoke which has been accelerated through the holes in the end wall of the receptable to strike the baffle plate at right angles and to then be turned through 90 . The smoke stream can then flow sideways across the baffle plate and into the expansion chamber through the apertures defined by the end wall, the baffle plates and the straps.

An annular plug is preferably provided in the end, ofthe expansion chamber distal to the end wall thereof. This annular plug serves to prevent conden; sate forming in the expansion chamber from running down the cigarette filter and coming into contact with the lips or tongue of a smoker. The annular plug preferably includes an inwardly projecting tubulaiflange formed on or adjacent its inner edge.

This flange further facilitates the retention of con densates in the chamber.

The mouthpiece preferably comprises a tubular member of substantially the same cross sectional size and shape over its full length. It is also preferably formed of a thin walled construction in order to minimise the weight of the cigarette filter. The free end of the mouthpiece is preferably formed with an end wall which is perforated with a plurality of holes each of which is spaced inwardly from the peripheral edge thereof. These holes are most preferably in the shape of elongate slots.

Hereinafter given by way of example only is a preferred embodiment of the present invention described with reference to the accompanying drawings in which: Fig. 1 is a perspective view of a tobacco smoke filtering device according to the present invention; Fig. 2 is a longitudinal sectional view of the tobacco smoke filtering device of Fig. 1; and Fig. 3 is a longitudinal sectional view through another embodiment of a tobacco smoke filter according to this invention.

The tobacco smoke filtering device 10 comprises a tubular receptacle 11 and a mouth-piece 12.

The tubular receptacle 11 is formed at one end with a cigarette receiving portion 13 which is cylindrical and is adapted to receive and firmly engage with the end of a cigarette. A cylindrical extension 14 extends coaxially from one end of the cigarette receiving portion 13 and is of slightly smaller diameterthan portion 13. The cylindrical extension 14is formed at its end adjacent the cigarette receiving portion 13 with a region of enlarged internal diameter into which is force fitted a metal disc 15 constituting orifice means to constrict the area of flow of the smoke stream and to thereby accelerate the smoke stream and a second metal disc 16 in face to face juxtaposition with the disc 15 and constituting a baffle means adapted to be impinged upon by the accelerated smoke stream such that tar and other substances are deposited on the baffle means. The dist 15 constituting the orifice means and the disc 16 constituting the baffle means will be hereinafter described in greater detail. The end of the cylindrical extension 14 distal to the cigarette receiving portion t3 is formed with an annular end wall 17 which is formed around the aperture defined by the wall 1i with an inturned lip 18. The end wall 17 and inturned lip 18 serve to retain material deposited on the baffle plate from flowing through the extension into the mouth-piece.

The disc 15 constituting the orifice means is formed on either side of its mid-point, and in diametrical alignment with a pair of small apertures 19. The area of the apertures 19 relative to the crosssectional area of the cigarette receiving portion 13 is such that the smoke stream is substantially accelerated on passing through the apertures 19 without being so small that undue effort must be exercised by the smoker in drawing the smoke stream through the apertures 19. The disc 16 constituting the baffle means includes a central zone 21 lying in a plane parallel to the plane of the remainder of the disc 16 but spaced slightly from it in a direction away from the disc 15. The central zone 21 is connected integrally with the remainder of the disc 16 by a pair of strap portions 22 which are diametrically opposed.

The mouth-piece is substantially cylindrical and is thin-walled as is shown in Figure 2. The mouth-piece 12 is substantially the same diameter as the cigarette receiving portion 13 of the receptacle 11 and fits about the extension 14. The mouth-piece 12 is formed with an end wall 23 having a plurality of elongate apertures 24. The apertures 24 are so arranged that they are spaced slightly from thetubu- lar wall of the mouth-piece such that any smoke condensate occurring within the mouth-piece will be prevented from coming into contact with the smoker's mouth.

The receptacle 11 and the mouth-piece are preferably injection moulded from a suitable synthetic plastics material. The receptacle may be formed of a clear plastics material or it may be formed from a coloured plastics material. It is preferred that the mouth-piece be of a coloured and opaque plastics material in orderthat condensate forming within the extension 14 is not visible when the mouth-piece is in place on the extension. It is preferred that the plastics material constituting the receptacle 11 is transparent or at least translucent such that a visual indication can be obtained of the extent to which tars and the like have been trapped within the filter.

The above described tobacco smoke filtering device is relatively cheap to produce, is light in weight and avoids excessive length. This reduced length and weight contribute to the comfort of the article being smoked in the mouth of a smoker and allows the use of the cylindrical mouth-piece described, there being no need to form on the mouth-piece lumps and ridges which can be gripped by the teeth of a smoker. The cylindrical nature of the mouth-piece preserves for the smoker of cigarettes the oral sensations received when smoking a cigarette without the use of a non-integral tobacco smoke filtering device.

With reference to Fig. 3, the cigarette filter 110 comprises a cylindrical cigarette receptacle 111 which nests within a tubular extension 112 of a cylindrical expansion chamber 113, and a substan tiallycylindrical mouthpiece 114.

The cigarette receptacle 111 is formed at its free end with a chamferred zone 115 to assist the insertion of the end of a cigarette into the receptacle 111.

Adjacent the chamber 113 the receptacle 111 is necked down so that its end portion 116 will fit within the tubular extension 112 and to form the outwardly facing, shoulder 117 which defines the limit of insertion of a cigarette into the receptacle 111.

The end wall 118 of the receptacle 111 is formed with two holes 119 spaced in diametric opposition across the mid-line of the receptacle 111. Each hole 119 is frusto-conical adjacent its inlet side and thereafter is cylindrical.

The expansion chamber 113 is cylindrical and of an external diameter equal to the internal diameter of the tubular extension 112 with an end wall 121 formed adjacent the annular zone of contact between the chamber 113 and its tubular extension 112.

A baffle plate 122 is formed in the mid-line of the end wall 121 and in axial alignment with the holes 119.

The baffle plate 122 is spaced out of the plane of the remainder of the wall 121 and is connected thereto by a pair of diametrically opposed strap portion 123.

A space is defined between the baffle plate 122 and the portions of the end wall 118 carrying the holes 119.

The end of the chamber 113 distai to the wall 121 is fitted with an annular plug 124. The plug 124 comprises an annular end wall 125 and a pair of coaxial tubular flanges 126 and 127. The radially outer flange 126 forms a friction fit with the inside of the chamber 113. The radially inner flange 127 surrounds the central aperture of the annular end wall 125.

The mouthpiece 114 includes a sleeve 128 and an end wall 129. The sleeve 128 is cylindrical over most of its length which surrounds in a friction fit the outside of the expansion chamber 113. The end of the sleeve portion 128 distal to the end wall 129 abuts against the tubular extension 112. Adjacent the end wall 129 the sleeve 128 tapers inwardly slightly such that at its end the sleeve has an external diameter substantially equal to its internal diameter at its other end.

The end wall 129 of the mouthpiece 14 is formed with five slots 131. Each slot stops short of the circumferential edge of the end wall 129.

In use a cigarette is fitted into the receptacle 111 and lit. Upon inhaling through the mouthpiece 114 a smoker draws smoke through the holes 119. This smoke stream is greatly accelerated by passing through the holes 119 and the stream strikes and baffle plate 122 with a considerable velocity. Tar and other particulate matter in the smoke stream is entrained on the baffle plate 122 as the gas stream is caused to rapidly change direction. After being diverted by the baffle plate 122 the smoke stream will pass through the apertures defined by the end wall 121, the baffle plate 122 and the straps 123.

Upon entering the expansion chamber 113 the gas stream will be slowed and will cool slightly allowing some condensation to take place before the smoke stream passes through the hole defined by the tubularflange 127 and the slots 131 into the mouth of the smoker. The flange 127 serves to prevent the condensate forming in the expansion chamber 113 from flowing out of the expansion chamber and into the mouthpiece.

If desired circumferential detents and detent grooves may be formed to hold together the recep tacle 111, the chamber 113 and the mouthpiece 114.

It is possible, however, to rely upon forming a friction fit between these parts to hold them together.

Claims (26)

1. A tobacco smoke filtering device for use with cigarettes, comprising a cylindrical tubular receptacle to receive an end of a cigarette, a mouth-piece and tobacco smoke filtering means disposed between the receptacle and the mouth-piece, the arrangement being characterised in that the mouth-piece is a thin-walled tubular element of substantially uniform cross-sectional shape and area throughout its length.

2. A tobacco smoke filtering device as claimed in claim 1 in which the end of the mouth-piece distal to the tubular receptacle is provided with an end wall in which are formed a number of apertures.

3. Atobacco smoke filtering device as claimed in claim 2 in which the apertures are all spaced radially inwardly from the tubular wall of the mouth-piece.

4. Atobacco smoke filtering device as claimed in any one of claims 1 to 3 in which the mouth-piece is of substantially circular cross sectional shape.

5. A tobacco smoke filtering device as claimed in any one of claims 1 to 4 in which the cross sectional area of the mouth-piece is similar to that of a conventional cigarette.

6. A tobacco smoke filtering device as claimed in any one of claims 1 to 5 in which the tobacco smoke filtering means comprises a juxtaposed orifice and baffle plate.

7. A tobacco smoke filtering device comprising a tubular receptacle adapted to receive a tobacco smoke source, the receptacle having at one end a tubular extension, there being fixedly disposed within the receptacle, andlor the extension, orifice means to constrict the area of flow of the smoke stream and to thereby accelerate the smoke stream, and baffle means arranged to be impinged upon by the accelerated smoke stream such that tar and other substances are deposited on the baffle means; and a mouth piece which is disposed about the extension and which projects beyond the extension away from the receptacle.

8. A tobacco smoke filtering device as claimed in claim 7 in which the receptacle is adapted to receive a cigarette as the tobacco smoke source and is cylindrical having an internal diameter substantially equal to the external diameter of a cigarette.

9. Atobacco smoke filtering device as claimed in claim 7 or claim 8 in which the tubular extension of the receptacle is formed at its end adjacent the receptacle with a portion of increased diameter adapted to receive a pair of discs constituting the orifice means and baffle means.

10. Atobacco smoke filtering device as claimed in claim 9 in which the metal discs constituting the orifice means and baffle means are held in place within the extension of the receptacle by being a force fit within the region of enlarged diameter of the extension.

11. A tobacco smoke filtering device as claimed in any one of claims 7 to 10 in which the end of the extension distal to the receptacle is provided with an annular end wall coaxial with the extension.

12. A tobacco smoke filtering device as claimed in claim 11 in which the aperture defined by the annular end wall is surrounded by a short tube extending inwardly into the extension and lying coaxially with the extension.

13. A tobacco smoke filtering device as claimed in claim 7 in which the orifice means and the baffle means comprise a pair of discs juxtaposed in face to face arrangement, the plate constituting the orifice means having a hole or holes therein and the plate constituting the baffle means having a planar portion lying at right angles to the axis of the hole or each ofthe holes and being spaced slightly downstream therefrom.

14. Atobacco smoke filtering device as claimed in any one of claims 7 to 13 in which receptacle and the extension thereof are formed of a transparent or translucent material.

15. A tobacco smoke filtering device as claimed in any one of claims 7 to 14 in which the mouth piece is formed from an opaque material.

16. A cigarette filter comprising a tubular cigarette receiving receptacle having an end wall formed integrally therewith, a tubular expansion chamber having an end wall formed integrally therewith, means to maintain the receptacle and the chamber in coaxial relationship with the end walls thereof in juxtaposition, and a tubular mouth piece coaxial with the receptacle and the chamber and surrounding the chamber over at least part of its length, a hole or holes extending through the end wall of the receptacle parallel to the axis thereof, the cross sectional area of the hole or of all of the holes being substantially smaller than the cross sectional area of the receptacle, the end wall of the expansion chamber including a baffle plate lying in a plane at right angles to the axis of the hole, or the parallel axes of the holes and spaced slightly therefrom, and an aperture or apertures being formed in the end wall of the chamber adjacent the baffle plate which aperture or apertures have a cross sectional area substantially greater than that of the hole or holes in the end wall of the receptacle.

17. A cigarette filter as claimed in claim 16 in which the component parts of the cigarette filter are injection moulded from a synthetic plastics material.

18. A cigarette filter as claimed in claim 16 or claim 17 in which the cigarette receptacle and the expansion chamber are formed of a transparent or translucent material and the mouthpiece is formed of an opaque material.

19. A cigarette filter as coaimed in any one of claims 16 to 18 in which the means to connect together the receptacle and the chamber comprises a tubular extension of either the receptacle or the chamber which receives the adjacent end of the other member in a sliding fit.

20. A cigarette filter as claimed in any one of claims 16 to 19 in which the or each hole in the end wall of the receptacle tapers over at least part of its length in a direction towards the mouthpiece.

21. A cigarette filter as claimed in any one of claims 16 to 20 in which an annular plug is provided in the end of the expansion chamberd distal to the end wall thereof.

22. A cigarette filter as claimed in claim 21 in which the annular plug includes an inwardly projecting tubular flange formed on or adjacent its inner edge.

23. A cigarette filter as claimed in any one of claims 16to 22 in which the mouthpiece comprises a tubular member of substantially the same cross sectional size and slope over its full length.

24. A cigarette filter as claimed in any one of claims 16 to 23 in which the free end of the mouthpiece is formed with an end wall which is perforated with a plurality of holes each of which is spaced inwardly from the peripheral edge thereof.

25. Atobacco smoke filtering devicesubstantially as hereinbefore described with reference to Figs. 1 and 3 or Fig. 3.

26. A cigarette filter substantially as hereinbefore described with reference to Fig. 3.