CA1191065A - Tobacco smoke filters - Google Patents

Tobacco smoke filters

Info

Publication number
CA1191065A
CA1191065A CA000420770A CA420770A CA1191065A CA 1191065 A CA1191065 A CA 1191065A CA 000420770 A CA000420770 A CA 000420770A CA 420770 A CA420770 A CA 420770A CA 1191065 A CA1191065 A CA 1191065A
Authority
CA
Canada
Prior art keywords
filter
filter plug
mouth end
grooves
airflow duct
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA000420770A
Other languages
French (fr)
Inventor
John A. Luke
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Brown and Williamson Holdings Inc
Original Assignee
Brown and Williamson Tobacco Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Brown and Williamson Tobacco Corp filed Critical Brown and Williamson Tobacco Corp
Application granted granted Critical
Publication of CA1191065A publication Critical patent/CA1191065A/en
Expired legal-status Critical Current

Links

Classifications

    • AHUMAN NECESSITIES
    • A24TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24DCIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES FOR CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
    • A24D3/00Tobacco smoke filters, e.g. filter-tips, filtering inserts; Filters specially adapted for simulated smoking devices; Mouthpieces for cigars or cigarettes
    • A24D3/04Tobacco smoke filters characterised by their shape or structure
    • A24D3/043Tobacco smoke filters characterised by their shape or structure with ventilation means, e.g. air dilution
    • AHUMAN NECESSITIES
    • A24TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
    • A24DCIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES FOR CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
    • A24D3/00Tobacco smoke filters, e.g. filter-tips, filtering inserts; Filters specially adapted for simulated smoking devices; Mouthpieces for cigars or cigarettes

Landscapes

  • Cigarettes, Filters, And Manufacturing Of Filters (AREA)

Abstract

TITLE OF THE INVENTION
IMPROVEMENTS RELATING TO TOBACCO SMOKE FILTERS

ABSTRACT OF THE DISCLOSURE
A smoke filter for a smoking article (e.g. a cigarette) comprises a filter plug having an airflow duct whose floor extends along the filter plug from the mouth end of the plug such that the end of the duct remote from the mouth end is deeper than the end of the duct at the mouth end, with a region of progressively decreasing depth from the deep end towards the shallow end. The at least one duct may comprise a plurality of grooves equiangularly spaced around the periphery of the filter plug, in which case it is possible for the grooves to extend helically and to be divided into sets of opposite hand such that each groove of one set intersects several grooves of the other set. Alternatively, the airflow duct may comprise a single annular groove extending around the filter plug with a shallower side at the mouth end of the plug and a deeper side remote from the mouth end, in which case a relatively stiff tipping is reguired. In all cases the tipping includes ventilation perforations communicating with the deeper end of the air duct.

Description

1191~6~i DESCRIPTION
IMPROVEME~TS RELATI~G T~ TOBACCO SMOKE FILTERS

This invention relates to tobacco smoke filters for use with smoking articles, cigarettes for exampl~.
It is well known to provide filter tipped cigarettes with ventilation means which permit the ingress of ventilation air into the filter. A purpose of this is to effect a decrease in the mainstream delivery of smoke components. It has been observed that when ventilation air flows into a filter comprising a plug of fibrous filtration material, cellulose acetate for example, through a ventilation zone extending around the filter the tobacco smoke is caused to pass out of the filter in an axial stream having a diameter less than the diameter of the end face of the filter plug.
This comparatively narrow stream of smoke impinges on a limited area of the taste receptors in the mouth of the smoker. I~ is an object of the present invention to provide a tobacco smoke filter in the use of which there occurs a stimulation of the taste receptors over a wider region in the smoker's mouth.
The present invention provides a smoke filter including a rod-like plug of filtration material and having at least one airflow duct at the periphery of said plug, wherein said at least one airflow duct has an ~9~6~i outlet opening at the mouth end of said plug and an inlet opening spaced fxom the mouth end, and wherein said at least one airflow duct has a region in which the depth progressively decreases along the airflow duct in a direction towards the mouth end of the plug.
Conveniently~ said at least one airflow duct I has its region of decreasing depth extending substantially up to the mouth end of the plug. Preferably there may be several said airflow ducts, each defined partly by a respective one of a plurality of grooves in the peripheral surface of the filter plug~ and partly by the i~wardly facing surface of wrapping means around the filter plus. In this case the width of the grooves may be constant or it may increase or decrease in the direction towards the mouth end of the filter plug.
In order that th~ invention may be clearly understood and readily carried into effect, reference will now be made, by way of example, to the diagrammatic drawing hereof, in which:-Fi~ure 1 shows a part view, in axial section, of a filter tipped cigarette, Figure 2 shows a mouth-end view of the filter of the cigarette of Figure 1, Figure 3 shows a mouth-end view of a filter of a somewhat different form from the filter shown in Figure 1 and 1~91065 Figure 4 shows a development view of a portion of the peripheral surface of a filter plug of another form.
The cigarette of Figure 1 comprises a rod 1 of cut tobacco enwrapped in cigarette paper 2, and a filter 3 comprising a self-sustaining filter plug 4 of fibrous cellulose acetate filtration material. At the periphery of the plug 4 there extend a number, eight as shown, of parallel, axially extending grooves 5 - see also Figure ~. As may be seen from Figure 1, the grooves 5, which extend from the mouth end of the plug 4 for a distance less than the full length of the plug, are so formed that the depth of each decreases towards and s~bstantially up to the mouth end of the plug. A
convenient method of forming the grooves 5 is to subject the plug 4, or preferably a filter rod length from which the plug was cut, to a hot-moulding process such as, for example, that disclosed in United Xingdom Patent Specification No. 1,507,765, using suitably shaped *orming means. The surfaces of the grooves 5 may be rendered impervious.
Serving to secure the filter 3 to the cigarette rod 1, 2 is a tipping 7 which, in the portions where it overlies the grooves 5, defines, together with the walls of the grooves 5, airflow ducts 8. A row of ventilation perforations 9, shown in exaggerated form, in the tipping 7 encircles the plug 4 at a location overlying the ~1065 upstream end of the grooves 5, the arrangement being such that there is in communication with each of the airflow ducts 8 at least one of the perforations 9.
When the cigarette of Figure 1 is smoked, ambient air is drawn through ~he ventilation perforations 9 into the airflow ducts 8. The air passes al-ong the airflow ducts 8 to the outlet ends thereof unmixed, or substantially unmixed, with tobacco smoke. Since the depth of the grooves 5 partly defining the airflow ducts 8 decreases in the direction of flow of the ventilation air along the ducts 8, the air exits the ducts 8 into the smoker's mouth with a component of velocity directed radially outwardly. There is thus provided a divergent air stream which entrains smoke issuing from the mouth end of the filter plug 4 by a Coanda effect and so causes the smoke to come into contact with taste receptors over a comparatively wide region of the smoker's mouth. This is perceived by the smoker as an enhanced smoke character.
The filter~ a mouth-end view of which is shown in Figure 3, comprises a plug 4' which, instead of being provided with ~ number of longitudinally extending peripheral grooves, comprises a single annular circumferential groove 5'. In axial section of the plug 4', the groove 5' has a contour similar to the contour of the base of each of the grooves 5 of the plug 1~9~65 4 of Figure l. A stiff wrapper sleeve or mouthpiece 7', which may be formed of plastics material, encases the plug 4' and receives an end portion of a cigarette rod in a manner analogous with the tipping 7 of the cigarette shown in Figure l. The sleeve 7' requires to be stiff in order that the annular mouth-end opening, designated 6, of airflow duct 8', defined by the circumferential annular gro~ve 5' and the sleeve 7', remains open when the filter is in use.
The effect produced by the filter of Figure 3 is similar to that of the filter 3 of Figures l and 2.
Ambient air is drawn into the airflow duct 8' through perforations (not shown) in the wrapper or mouthpiece 7' and, because of the contour of the groove 5, the air enters the ~moker's mouth as a divergent stream which serves to cause smoke to impinge on an extended region of taste receptors.
Figure 4 shows, as a development view, a pattern of peripheral grooves which may be utilised as an alternative to the axially extending grooves 5 of the filter of Figure l or the single annular circumferential groove 5' of the filter of Figure 3. In Figure 4 reference numeral lO denotes the mouth end of a filter plug 11. A first series has per.ipheral, parallel grooves 13 extending at a small angle to the axis of the plug 11 and the grooves 14 of a second, similar ~191065 series extend at substantially the same angle to the axis but with opposite hand. The two sets of grooves 13, 14 intersect to produce a reticular formation. As with the single series of grooves 5, each of the grooves 13, 14 has a region of decreasing depth in the direction towards and substantially up to the mouth end 10 of the plug 11~ In use the plug 11 is overwrapped by a wrapper (n~t shown) permitting ventilation air to flow into the grooves 13, 14 at upstream locations thereof and a smoke-spreading effect is achieved similar to that exhibited by the previousl~ described filters.
The wrapping means for the filter plug may comprise a plug wrapper of pervious nature on the 1~ plug exterior and a longer tipping of impervious nature overlying the plug wrapper and securing the filter plug to the tobacco rod 2. In this case the ventilation perforations need only be present in the impervious tipping.
The ilter plug may, if desired7 be formed as two sub-plugs one of which has the grooves 5, 13, 14 or the single circumferential groove 5' therein, the other sub-plug being plain.
If desired, the ventilation perforations may comprise a micro-perforated region of the tipping.

Claims (20)

The embodiments of the invention, in which an exclusive privilege or property is claimed, are defined as follows:
1. In a smoke filter including:
(a) rod-like filter plug means of filtration material having a mouth end;
(b) airflow duct means at the periphery of said filter plug means, and (c) means defining an outlet opening of said airflow duct means at the mouth end of said filter plug means and an inlet opening spaced from the mouth end, the improvement wherein:-(d) said airflow duct means has a region in which said airflow duct means has a depth, measured radially of the filter plug means, which progressively decreases along the airflow duct means in a direction towards said mouth end of the filter plug means.
2. A filter according to claim 1, and further including wrapping means enwrapping said filter plug means and means adapted to permit the ingress of ambient air into said airflow duct means, said airflow duct means having a part which is remote from said mouth end of said filter plug means and is adapted to receive said ambient air ingress permitted by said wrapping means.
3. A filter according to claim 2, wherein said airflow duct means comprises several said airflow ducts;
wherein said wrapping means has an inwardly facing surface contiguous with said filter plug means, and wherein said filter plug means has a plurality of longitudinal peripheral grooves corresponding to said several airflow ducts, each said airflow duct being defined partly by a respective one of said grooves and partly by the inwardly facing surface of the wrapping means.
4. A filter according to claim 3, wherein each of said grooves has a constant width.
5. A filter according to claim 3, wherein each of said grooves has a width which increases in a direction towards said mouth end of the filter plug means.
6. A filter according to claim 3, wherein each said groove has a floor surface which is impervious to air.
7. A filter according to claim 6, wherein each said groove has side surfaces which are impervious to air.
8. A filter according to claim 2, wherein said wrapping means includes ventilation perforation means to permit said ingress of air into said part of the airflow duct means.
9. A filter according to claim 8, wherein said ventilation perforation means comprise a micro-perforated region in the wrapping means.
10. A filter according to claim 2, wherein said wrapping means includes:-(i) an inner layer of air-pervious material, (ii) an outer layer which is less pervious to air and (iii)ventilation perforation means in said less pervious outer layer to permit ingress of air into said part of said airflow duct means.
11. A filter according to claim 1,2 or 3, wherein said region of progressively decreasing depth of said airflow duct means continues substantially to said mouth end of the filter plug means.
12. In a smoke filter including:
(a) rod-like filter plug means of filtration material havinq a mouth end, (b) airflow duct means at the periphery of said filter plug means; and (c) means defining an outlet opening of said airflow duct means at the mouth end of said filter plug means and an inlet opening spaced from the mouth end, the improvement wherein:-(d) said airflow duct means comprise first and second sets of helical airflow ducts around said filter plug means, (e) said filter plug means includes first and second sets of helical grooves extending peripherally thereof with said first set of grooves corresponding to said first set of airflow ducts and being of a first hand, and said second set of grooves corresponding to said second set of airflow ducts and being of opposite hand, whereby at least one of the grooves of said first set intersects several of the grooves of said second set;

(f) each of said grooves of each of said first and second sets has an inlet end and an outlet end with said outlet end nearer to said mouth end of the filter plug means, and (g) each of said grooves of each of said first and second sets has a region which has a depth progressively reducing along a direction from said inlet end towards said outlet end thereof.
13. A filter according to claim 12, wherein said region of progressively reducing depth of each said groove continues substantially to said mouth end of the filter plug means.
14. A filter according to claim 12, and further including wrapping means enwrapping said filter plug means, and means adapted to permit the ingress of ambient air through said wrapping means to the grooves of said first and second sets, each of said grooves having a part thereof which is remote from said mouth end of said filter plug means and is in register with said ingress-permitting means of the wrapping means.
15. A filter according to claim 12,13 or 14, wherein each said groove has a floor surface and side surfaces, and said floor and side surfaces are impervious to air.
16. In a smoke filter including:-(a) rod-like filter plug means of filtration material having a mouth end:
(b) wrapping means enwrapping said filter plug means and having an inner surface contiguous with said filter plug means, (c) airflow duct means between the exterior of said filter plug means and said wrapping means, and (d) means defining an outlet opening of said airflow duct means at the mouth end of said filter plug means and an inlet opening spaced from the mouth end, the improvement wherein:-(e) said airflow duct means comprise an annular groove extending around said filter plug means and having first and second sides, said first side being at said mouth end of said filter plug means and having a depth which is greater than the depth of said second side which is spaced from the mouth end of said filter plug means, and (f) said annular groove includes a region in which the depth of the groove progressively reduces in a direction extending transversely of said groove from said second side towards said first side thereof.
17. A filter according to claim 16, wherein said wrapping means comprise a relatively stiff outer sleeve around and encasing said filter plug means, said sleeve terminating at the mouth end of said filter plug means wherein said means defining an outlet opening of said airflow duct means comprise means defining a clearance between the exterior of the filter plug means and said inner surface of said sleeve, and wherein said sleeve includes ventilation perforation means disposed therearound and overlying said second side of said annular groove and adapted to communicate with said airflow duct means defined by said annular groove.
18. A filter according to claim 16, wherein said annular groove has a floor surface which is impervious to air.
19. A filter according to claim 16,17 or 18, wherein said region of progressively decreasing depth transversely of said groove continues substantially to said mouth end of the filter plug means.
20. A tobacco smoking article including a smoke filter according to claim 16,17 or 18, and a tobacco rod abutting and coaxial with said smoke filter; wherein said sleeve overlies the whole of said filter plug means and at least part of said tobacco rod.
CA000420770A 1982-02-02 1983-02-02 Tobacco smoke filters Expired CA1191065A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8202945 1982-02-02
GB8202945 1982-02-02

Publications (1)

Publication Number Publication Date
CA1191065A true CA1191065A (en) 1985-07-30

Family

ID=10528056

Family Applications (1)

Application Number Title Priority Date Filing Date
CA000420770A Expired CA1191065A (en) 1982-02-02 1983-02-02 Tobacco smoke filters

Country Status (33)

Country Link
JP (1) JPS58165782A (en)
KR (1) KR840003399A (en)
AT (1) ATA19983A (en)
AU (1) AU548841B2 (en)
BE (1) BE895755A (en)
BR (1) BR8300492A (en)
CA (1) CA1191065A (en)
DE (1) DE3303301C2 (en)
DK (1) DK39283A (en)
ES (1) ES278856Y (en)
FI (1) FI68953C (en)
FR (1) FR2520595A1 (en)
GB (1) GB2115679B (en)
HK (1) HK28686A (en)
HU (1) HU188420B (en)
IL (1) IL67731A (en)
IN (1) IN157858B (en)
IT (1) IT1163073B (en)
KE (1) KE3598A (en)
LU (1) LU84620A1 (en)
MY (1) MY8700716A (en)
NL (1) NL8300379A (en)
NO (1) NO830333L (en)
NZ (1) NZ203133A (en)
PH (1) PH19178A (en)
PL (1) PL240392A1 (en)
RO (1) RO87088A (en)
SE (1) SE8300443L (en)
SG (1) SG92485G (en)
TR (1) TR21429A (en)
YU (1) YU23683A (en)
ZA (1) ZA83652B (en)
ZW (1) ZW2183A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB201605101D0 (en) 2016-03-24 2016-05-11 Nicoventures Holdings Ltd Electronic vapour provision system
GB201605100D0 (en) 2016-03-24 2016-05-11 Nicoventures Holdings Ltd Vapour provision system
GB201605105D0 (en) 2016-03-24 2016-05-11 Nicoventures Holdings Ltd Vapour provision apparatus

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1278914B (en) * 1963-11-07 1968-09-26 Anthony Paul Miller Cigarette
FR2109761A5 (en) * 1970-10-05 1972-05-26 Eastman Kodak Co
US4256122A (en) * 1979-04-11 1981-03-17 Brown & Williamson Tobacco Corporation Cigarette filter
DE3068598D1 (en) * 1979-09-07 1984-08-23 Philip Morris Inc Cigaret mouthpiece

Also Published As

Publication number Publication date
FI830211A0 (en) 1983-01-21
IN157858B (en) 1986-07-12
BR8300492A (en) 1983-11-01
FI68953C (en) 1985-12-10
RO87088A (en) 1986-07-30
IT8319395A0 (en) 1983-02-02
HU188420B (en) 1986-04-28
FI830211L (en) 1983-08-03
PL240392A1 (en) 1983-08-15
KR840003399A (en) 1984-09-08
NO830333L (en) 1983-08-03
AU1077783A (en) 1983-08-11
HK28686A (en) 1986-04-25
PH19178A (en) 1986-01-23
SE8300443D0 (en) 1983-01-28
AU548841B2 (en) 1986-01-02
GB2115679A (en) 1983-09-14
ZW2183A1 (en) 1983-08-03
YU23683A (en) 1985-10-31
BE895755A (en) 1983-05-16
TR21429A (en) 1984-05-01
DE3303301A1 (en) 1983-08-11
MY8700716A (en) 1987-12-31
GB2115679B (en) 1985-09-11
LU84620A1 (en) 1983-09-08
FR2520595A1 (en) 1983-08-05
JPS58165782A (en) 1983-09-30
IL67731A0 (en) 1983-05-15
DK39283D0 (en) 1983-02-01
KE3598A (en) 1986-02-07
ES278856U (en) 1984-08-01
FR2520595B1 (en) 1985-03-22
FI68953B (en) 1985-08-30
ES278856Y (en) 1985-03-01
ZA83652B (en) 1983-10-26
DK39283A (en) 1983-08-03
GB8300875D0 (en) 1983-02-16
JPS6126352B2 (en) 1986-06-20
SG92485G (en) 1987-09-18
IT1163073B (en) 1987-04-08
NZ203133A (en) 1985-04-30
DE3303301C2 (en) 1985-05-23
IL67731A (en) 1987-07-31
NL8300379A (en) 1983-09-01
SE8300443L (en) 1983-08-03
ATA19983A (en) 1986-09-15

Similar Documents

Publication Publication Date Title
US4380241A (en) Smoking articles
KR100737573B1 (en) Ventilated smoking article
US4942887A (en) Filter mouthpiece for a smoking article
JPS5832955B2 (en) cigarette filter
US3240213A (en) Cigarette
US3504677A (en) Cigarette and/or cigarette holder
US4616664A (en) Tobacco product
CA1191065A (en) Tobacco smoke filters
US4476882A (en) Tobacco smoke filters
US4644963A (en) Smoking articles
US4660576A (en) Smoking articles
JPH0259716B2 (en)
US4649942A (en) Smoking articles
US4527572A (en) Tobacco smoke filters
US4700724A (en) Smoking-articles mouthpieces-elements
CA1192468A (en) Smoke filters
US4478229A (en) Smoke filters
GB2095532A (en) Ventilated and corrugated smoke filter
CA1260791A (en) Smoking articles
GB2158689A (en) Improvements relating to smoking articles
NL8302782A (en) IMPROVEMENTS REGARDING SMOKE FILTERS.
GB2171885A (en) Improvements relating to smoking article mouthpieces
US4724848A (en) Smoking article filters
GB2115678A (en) Improvements relating to tobacco smoke filters
KR100804877B1 (en) Ventilated smoking article

Legal Events

Date Code Title Description
MKEC Expiry (correction)
MKEX Expiry