US3596664A

US3596664A - Filter cigarette

Info

Publication number: US3596664A
Application number: US859969A
Authority: US
Inventors: Jesse R Pinkham
Original assignee: RJ Reynolds Tobacco Co
Current assignee: RJ Reynolds Tobacco Co
Priority date: 1969-09-22
Filing date: 1969-09-22
Publication date: 1971-08-03
Anticipated expiration: 1988-08-03

Abstract

A filter cigarette is provided which includes an elongated tobacco rod and an axially aligned filter assembly affixed to one end thereof. The filter assembly comprises a smoke-impervious core piece, and a smoke-pervious member disposed in abutting relation with respect to the downstream end of the core piece. The core piece is provided with a plurality of elongated facets; each facet being provided with an elongated indentation through which smoke is adapted to flow. The core piece is encompassed by a thin perforated membrane having perforations thereof aligned with the indentations. A sleeve is also provided which encompasses the perforated membrane. Portions of the sleeve and perforated membrane are in spaced relation and form a plurality of elongated longitudinally extending shallow passageways through which smoke is adapted to flow. Each passageway is in communication with an adjacent indentation through a membrane perforation. The smoke is emitted from the membrane perforations at a very high velocity and impinges against an adjacent surface before flowing through the smoke-pervious member.

Description

ited States Patent [72] Inventor Jess: R. Pinklnm Winston-Salem, N.'C. [21] AppLNo. 859,969 [22] Filed Sept. 22, 1969 [45] Patented Aug. 3, 1971 [73] Assignee RJ. Reynoltb Tobacco Co.

Winston-Salem, N.C.

[54] FILTER CIGARETTE 18 Claims, 2 Drawing Figs.

[52] US. Cl 131/10.5,

1311107. 131/201 [51] Int. CL ..A24d 01/04 [50] Field ofSearch 131/10.5, 10.7, 201, 210, 261 B, 216

[56] References Cited UNITED STATES PATENTS 1,996,990 4/1935 Cullen 13 l/10.5 2,954,774 10/1960 Lebert l3 l/10.5 3,472,238 10/1969 Blount et al. 131/201 X 3,496,946 2/1970 Griffith 13l/10.5

FOREIGN PATENTS 1,508,121 11/1967 France 131/261 B 234,188 12/1944 Switzerland ABSTRACT: A filter cigarette is provided which includes an elongated tobacco rod and an axially aligned filter assembly affixed to one end thereof. The filter assembly comprises a smoke-impervious core piece, and a smoke-pervious member disposed in abutting relation with respect to the downstream end of the core piece. The core piece is provided with a plurality of elongated facets; each facet being provided with an elongated indentation through which smoke is adapted to flow. The core piece is encompassed by a thin perforated membrane having perforations thereof aligned with the indentations. A sleeve is also provided which encompasses the perforated membrane. Portions of the sleeve and perforated membrane are in spaced relation and form a plurality of elongated longitudinally extending shallow passageways through which smoke is adapted to flow. Each passageway is in communication with an adjacent indentation through a membrane perforation. The smoke is emitted from the membrane perforations at a very high velocity and impinges against an adjacent surface before flowing through the smoke-pervious member.

PATENTED AUS 3 WI SHEET 1 0F 2 FILTER CIGARETTE BACKGROUND OF THE INVENTION It is important that a filter cigarette to be commercially acceptable he possessed of certain characteristics such as (a) that it is of simple inexpensive construction; (b) that it can be assembled at speeds comparable to those presently used in forming filter or nonfiltercigarettes; (c) that it is efficient in removing solid and/or liquid particles from the circulating smoke without causing a substantial pressure buildup across the filter assembly during smoking of the cigarette; and (d) that the filter assembly will not have a deleterious effect on the taste and aroma of the smoke. Heretofore various filter cigarettes have been provided; however, because of certain design features they lack one or more of the aforesaid characteristics.

SUMMARY OF THE INVENTION Thus, it is an object of this invention to provide a filter cigarette which possesses all of the aforenoted desirable characteristics.

It is a further object of this invention to provide a filter cigarette wherein the various component parts thereof may be formed by utilizing techniques and methods well known in the cigarette-making art.

Further and additional objects will appear from the description, accompanying drawings, and appended claims.

In accordance with one embodiment of the invention a filter cigarette is provided which comprises an elongated tobacco rod, and a filter assembly affixed to one end thereof. The assembly in one form includes a smoke-impervious core piece which is disposed in abutting axial alignment with respect to the rod one end, and a smoke-pervious member disposed in abutting axial alignment with the downstream end of the core piece. The exterior of the core piece is provided with a plurality of elongated, longitudinally extending facets, each of which being provided with an elongated indentation which is closed at one end and open at the other end. Overwrapping the core piece exterior is a thin perforated membrane. Each core piece indentation has a membrane perforation in registration therewith. Encompassing the perforated membrane is an elongated smoke-impervious sleeve. Portions of the sleeve and the perforated membrane are disposed in spaced relation and form a plurality of elongated, longitudinally extending shallow passageways. Each passageway is in communication with an adjacent indentation through a membrane perforation. The configuration of each perforation is such that smoke is emitted therefrom at a very high velocity. The high velocity smoke impinges against an adjacent surface causing solid and/or liquid particles entrained in the smoke to be deposited on said adjacent surface prior to the smoke flowing through the smoke-pervious member.

DESCRIPTION For a more complete understanding of the invention reference should be made to the drawings wherein:

FIG. 1 is an enlarged fragmentary side elevational view of one form of the improved filter cigarette and with a portion thereof shown in a section taken along line 1-1 of FIG. 2.

FIG. 2 is an elevational view of the upstream end of the filter assembly shown in FIG. 1.

FIG. 3 is similar to FIG. 1 but showing a first modified form of the improved filter cigarette; portions of the latter being shown in a section taken along line 3--3 of FIG. 4. FIG. 4 is an elevational view of the upstream end of the filter assembly shown in FIG. 3.

FIG. 5 is similar to FIG. 1 but showing a second modified form of the improved filter cigarette; portions of the latter being shown in a section taken along line 55 of FIG. 6.

FIG. 6 is an elevational view of the upstream end of the filter assembly shown in FIG. 5.

FIG. 7 is similar to FIG. 1, but showing a third modified form of the improved filter cigarette; portions of the latter being shown in a section taken along line 7-7 of FIG. 8.

FIG. 8 is a sectional view taken along line 8-8 of FIG. 7.

Referring now to the drawings and more particularly to FIGS. 1 and 2, one form 10 of the improved filter cigarette is shown. The cigarette 10 includes an elongated tobacco rod 11 having a core 12 of compacted shreds of blended tobacco which is encompassed by a wrapper 13 of suitable thin cigarette paper. Secured to an end 11a of the rod 11 by a sleeve 14 of tipping paper is a filter assembly 15.

The assembly 15 in the illustrated embodiment includes an elongated core piece 16 which is formed of a suitable smokeimpervious material (e.g. an extruded foam plastic, such as expanded polystyrene), and an elongated cylindrically shaped member 17 formed of a smoke-pervious material (e.g. fibers of cellulose derivative such as Estron).

The exterior of the core piece 16 is provided with a plurality (four in number) of elongated, longitudinally extending, symmetrically arranged facets or planar faces 18. The facets are separated from one another by arcuate elongated portions 20, see FIG. 2. Each facet 18 is provided with an elongated longitudinally extending indentation 21. Each indentation 21 is closed at one end 21a. The portions 21b of the indentation adjacent the closed end thereof is shallower, or of less depth, than the remainder of the indentation. The downstream end 210 of each indentation is open and terminates at the smokepervious member 17.

Encompassing the core piece 16 is a thin perforated membrane 22 which may be formed of paper, foil, or plastic film. One or more of the perforations 23 formed in the membrane are disposed in registered relation with respect to the portion 21b of an adjacent indentation 21. The membrane 22 is adhesively secured to the arcuate exterior portions 20 of the core piece 16. Because of the configuration of portions 20, good adhesive bond can be obtained between the membrane and the core piece. Overlapping of the membrane opposite edges may occur at one of the arcuate portions.

Encircling the membrane 22 and the smoke-pervious member 17 is an elongated sleeve 24. The sleeve retains the core piece and member 17 in aligned, abutting relation, see FIG. 1. The sleeve is cylindrical in configuration and cooperates with the portions of the membrane 22 overlying the core piece facets 18 to form a plurality of elongated passageways 25. The upstream end 25a of each passageway is in communication with the end 1 1a of the tobacco rod 11. The downstream end 25b of each passageway, on the other hand, is blocked by a smoke barrier 26 which in the FIG. 1 embodiment may be formed by a bead of adhesive applied to the interior surface of the sleeve 24 prior to the latter being brought into encircling relation with the core piece and member. By reason of the smoke barrier 26 which is located downstream of the membrane perforations 23, the smoke, which is drawn into the passageway 25 upon suction being applied to the downstream end 17a of member 17, is caused to flow through the perforations 23 into the indentations 21 and then from the indentations through the member 17. The perforations 23 which are preferably arranged in an encircling row are sized (e.g. 0.0l0-inch diameter where 12 perforations are utilized; three for each indentation) so as to cause the smoke upon being emitted from the perforations to attain a very high velocity. The high velocity smoke impinges against an adjacent surface (in the FIG. 1 embodiment, the adjacent surface is that of the raised portion 21b of the indentation). Due to the impingement of the smoke, the solid and/or liquid particles entrained in the smoke are deposited on the adjacent surface before the smoke continues on to member 17 In order to have optimum deposit of said solid and/or liquid particles on the adjacent surface, when the initial pressure buildup across the filter assembly is approximately 2.0 inches of water, it is preferred that the distance between the perforations and the adjacent surface (portion 21b) be within the range from ap proximately 0.008 inch to approximately 0.015 inch. The

filter assembly as previously mentioned is secured to the rod end 11a by a sleeve 14 of tipping paper. Because of the direction of smoke flow through tee membrane perforations 23, filter assembly 15 is designated as an Out to In style.

The indentations 21 of core piece 16 are normally formed by after-forming wheels, not shown, which engage the periphery of the core piece after it has been extruded. The after-forming wheel technique is well known in the art and permits accurate dimensioning of the indentations. Thus, with the Out to In filter assembly 15, the spacing between the membrane perforations 23 and portion 21b of the indentation can be arcuately'controlled and maintained during smoking of the cigarette.

FIGS. 3 and 4 illustrate a first modified filter assembly 115 which is the same structurally as filter assembly 15, except core piece 116 is in an inverted position with respect to the smoke-pervious member 117. Corresponding parts comprising filter assemblies 15 and 115 are given like identifying numerals, except as to assembly 115 they will be in the 100 series. The same procedure will be followed as to the other modified assemblies to be hereinafter described except said numerals will be in the 200 and 300 series.

By reason of inverted disposition of the core piece 1 16, the smoke upon leaving the rod end 11a passes initially through the indentations 121, then out through the membrane perforations 123 and into the elongated passageway 125. With assembly 115, the high velocity smoke emitted from perforations 123 impinges against the adjacent surface, which is the portion of the interior surface of the sleeve 124 opposite the perforation. The distance between the perforations 123 and the sleeve surface portion should be approximately 0.008 inch to approximately 0.015 inch.

In both assemblies 15 and 115, the smoke-

pervious member

17 or 117 has a cross-sectional configuration which approximates that of the rod end 110 and thus, simplifies assembly of the various component parts of the filter assembly to the tobacco rod.

FIGS. 5 and 6 show a modified form of improved filter assembly 215 wherein both the core piece 216 and the smokepervious member 217 have a substantially hexagonal crosssectional configuration, see FIG. 6. As in the case of the

aforedescribed core pieces

17 and 117, the exterior surface of core piece 216 is provided with a plurality of elongated, longitudinally extending facets 218, each of which has formed therein an elongated, longitudinally extending indentation 221. The hexagonal configuration of core piece 216 is formed preferably by extrusion, and the indentations 221, in turn, are formed by means of after-forming wheels or the like.

Encompassing both the core piece 216 and smoke-pervious member 217 is a thin perforated membrane 222 which is formed of the same material as in the case of

membrane

22 or 122 previously described. Membrane 222, in addition to providing perforations 223 in registration with the indentations 221, serves also as a means for retaining the core piece 216 and member 217 in aligned, abutting relation.

Encompassing the exterior of membrane 222 is a cylindrically shaped sleeve 224. The interior surface of sleeve 224, in registered relation with the core piece facets 218, is spaced from the latter and cooperates therewith to form a plurality of longitudinally extending passageways 225. Each passageway has an open upstream end 225a which tenninates at the rod end 11a. In order to assure diversion of the smoke from the passageways 225 through the membrane perforations 223, each passageway has the downstream end thereof closed off by a smoke barrier 226 which is formed by an elongated depression formed in the downstream portion of the sleeve 224.

Each depression 226 takes the form of a circular segment. The corners 220 formed between adjacent facets 218 of the core piece supportingly engage the interior surface of the sleeve 224. Sleeve 224 may, if desired, serve a dual function namely; (a) to form the passageways 225, and (b) to act as tipping paper for securing the core piece and member to the end of the tobacco rod. The assembly 215, as illustrated, shows the sleeve 224 functioning in said dual capacity.

Each indentation 221 has a portion 221b adjacent the closed end 221a thereof of lesser depth than the remainder of the indentation. Each indentation portion 221b is opposite a membrane perforation 223 so that the high velocity smoke emitted inwardly through the perforation will impinge against said portion 221b and effect deposition of the smoke solid and/or liquid particles thereon. Like filter assembly 15, the second modified filter assembly 215 may be designated as an Out to In" style.

The third modified filter assembly 315, shown in FIGS. 7 and 8 closely resembles assembly 215, except that the core piece 316 is disposed in inverted relation with respect to the smoke-pervious member 317. By reason of this inversion and in order to assure that the initial flow of the smoke, upon leaving the tobacco rod, is directed through the open ends of the core piece indentations 321, the sleeve 324 is provided with two rows A and B of smoke barrier-forming depressions 326. The row A of depressions is disposed upstream of the perforations 323 and the row B of depressions is disposed downstream of the downstream end of the core piece 316. Each of the depressions 326 is again in the form of a circular segment.

To permit the smoke to flow from the passageways 325, formed by the interior surface of sleeve 324 and the facets 318 of the core piece, through the smoke-pervious member 317 it is necessary that membrane 322 be provided with a second set of perforations 323a which are arranged in encircling relation with respect to member 317, see FIG. 7. The second set of perforations 323a are of larger size than the first set of perforations 323 and thus, do not contribute in any significant way to the pressure buildup created by the filter assembly. If

desired, the sleeve 324 may be overwrapped by a sleeve, not shown, of tipping paper. In the embodiment illustrated in FIG. 7, no additional sleeve is required.

While four variations of the improved filter cigarette have been disclosed, the invention is not intended to be limited thereto. For example, two or more smoke-pervious members (one being of a cellulose derivative and the other being of a bonded granular material) arranged in tandem relation may be employed in combination with the core piece. Furthermore, the number of facets and the shape of the indentations formed therein may be varied from that shown without departing from the scope of the invention.

Thus, it will be seen that an improved filter cigarette has been provided which is inexpensive and may be easily and expeditiously assembled utilizing techniques and methods well known in the cigarette-making art. Furthermore, the improved filter assembly is highly effective in removing the solid and/or liquid particles from the smoke and in no way deleteriously afiects the taste and aroma of the smoke.

Iclaim:

1. A filter cigarette comprising an elongated tobacco rod and a filter assembly affixed to one end of said rod; said assembly including an elongated core piece of smoke-impervious material disposed in axially aligned abutting relation with respect to said rod one end, said core piece having a plurality of elongated facets on its peripheral exterior, each facet being provided with an elongated indentation, through which smoke is caused to flow, said facets being separated from one another by elongated arcuate unindented portions; an elongated smoke-pervious member abutting the downstream end of said core piece; a perforated membrane overlying each core piece indentation; and a sleeve encompassing and being secured to said core piece exterior, portions of said sleeve being in registered spaced relation with respect to each facet and the perforated membrane overlying same, and cooperating therewith to form a plurality of elongated shallow passageways through which smoke is caused to flow, each passageway being in communication with a core piece indentation through a membrane perforation, each perforation being of such dimension that smoke passes therethrough at a high velocity whereby the solid and/or liquid particles entrained in the emitted smoke impinge against and are deposited on a surface disposed in close proximity to said membrane perforation prior to the smoke continuing its flow through said smoke-pervious member.

2. A filter cigarette comprising an elongated tobacco rod and a filter assembly affixed to one end of said rod; said assembly including an elongated core piece of smoke-impervious material disposed in axially aligned abutting relation with respect to said rod one end, said core piece having a plurality of elongated facets on its peripheral exterior, each facet being provided with an elongated indentation, through which smoke is caused to flow, said facets being separated from one another by elongated arcuate unindented portions; a perforated membrane overlying each core piece indentation; and a sleeve encompassing and being secured to said core piece exterior, portions of said sleeve being in registered spaced relation with respect to each facet and the perforated membrane overlying same, and cooperating therewith to form a plurality of elongated shallow passageways through which smoke is caused to flow, each passageway being in communication with a core piece indentation through a membrane perforation, each perforation being of such dimension that smoke passes therethrough at a high velocity whereby the solid and/or liquid particles entrained in the emitted smoke impinge against and are deposited on a surface disposed in close proximity to said membrane perforation prior to the smoke continuing its flow through said filter assembly.

3. The filter cigarette of claim 2 wherein said indentations are closed at a corresponding one end.

4. The filter cigarette of claim 3 wherein the maximum depth of each indentation adjacent the membrane perforation is less than the maximum depth of the remainder of said indentation.

5. The filter cigarette of claim 2 wherein the perforated membrane encompasses said core piece and is secured to the arcuate unindented portions of said core piece.

6. The filter cigarette of claim 1 wherein said smoke-pervious member is formed of bonded granules of activated charcoal.

7. The filter cigarette of claim 1 wherein said smoke-pervious member is formed of a cellulose derivative.

8. The filter cigarette of claim 2 wherein the surface against which the high velocity smoke impinges comprises the passageway-forming surface of said sleeve.

9. The filter cigarette of claim 2 wherein the surface against which the highvelocity smoke impinges comprises a portion of said indentation.

10. The filter cigarette of claim 8 wherein each indentation has a closed end and an open end and the open end of each indentation is disposed adjacent said tobacco rod one end.

11. The filter cigarette of claim 1 wherein each indentation has a closed end and an open end and the open end of each indentation is disposed adjacent to said smoke-pervious member.

12. The filter cigarette of claim 2 wherein said elongated core piece is provided with four, symmetrically arranged, longitudinally extending facets.

13. The filter cigarette of claim 12 wherein the longitudinal dimension of each core piece indentation is less than the overall longitudinal dimension of said core piece.

14. The filter cigarette of claim 1 wherein said smoke-pervious member has substantially the same cross-sectional configuration as said tobacco rod one end.

15. The filter cigarette of claim 1 wherein said core piece and said smoke-pervious member have substantially the same cross-sectional configuration.

16. The filter cigarette of claim 15 wherein the sleeve therefor is provided with a plurality of inwardly extending smoke-barrier projections arranged in two longitudinally spaced rows, one of said rows encircling said smoke-pcrvious member and the other of said rows encircling said core piece; corresponding profjections of each row bein in registration with an elongated acet of said core piece an defining an end limit of the shallow passageway formed by the facet.

17. The filter cigarette of claim 2 wherein said sleeve includes a plurality of inwardly extending smoke-barrier projections, each projection being in registration with a passageway and forming one end limit thereof.

18. The filter cigarette of claim 2'wherein the smoke flow through said perforated membrane is in an out to in direction and the portion of each indentation adjacent the closed end thereof comprising an impingement targetarea for the high velocity smoke flowing through the adjacent membrane perforations, said target area remaining at a predetermined distance from the adjacent membrane perforations during the high velocity smoke flow therethrough.

Claims

9. The filter cigarette of claim 2 wherein the surface against which the high velocity smoke impinges comprises a portion of said indentation.

16. The filter cigarette of claim 15 wherein the sleeve therefor is provided with a plurality of inwardly extending smoke-barrier projections arranged in two longitudinally spaced rows, one of said rows encircling said smoke-pervious member and the other of said rows encircling said core piece; corresponding projections of each row being in registration with an elongated facet of said core piece and defining an end limit of the shallow passageway formed by the facet.

18. The filter cigarette of claim 2 wherein the smoke flow through said perforated membrane is in an out to in direction and the portion of each indentation adjacent the closed end thereof comprising an impingement target area for the high velocity smoke flowing through the adjacent membrane perforations, said target area remaining at a predetermined distance from the adjacent membrane perforations during the high velocity smoke flow therethrough.