US3651819A

US3651819A - Smoke filter

Info

Publication number: US3651819A
Application number: US17606A
Authority: US
Inventors: Hoyt S Beard
Original assignee: RJ Reynolds Tobacco Co
Current assignee: RJ Reynolds Tobacco Co
Priority date: 1970-03-09
Filing date: 1970-03-09
Publication date: 1972-03-28
Anticipated expiration: 1989-03-28
Also published as: CA926258A

Abstract

A smoke filter is provided which is adapted to be affixed to one end of a tobacco rod. The filter includes a first passageway through which smoke initially flows, a thin perforated membrane forming one wall of the first passageway and through which the smoke flows as a plurality of high velocity jets, and a second passageway separated from said first passageway by the perforated membrane. The second passageway has a surface against which the smoke jets impinge prior to flowing through the remainder of the second passageway. A predetermined area of a surface in the second passageway is formed of an absorptive material which is contacted by the smoke flowing through the second passageway.

Description

[Jnited States card [ SMOKE FILTER [72] Inventor: lloyt S. Beard, Winston-Salem, N.C.

[22] Filed: Mar. 9, 1970 [21] Appl.No.: 17,606

[52] 11.8. CL ..l3l/261B,131/199,131/201, 131/204,131/210 [51] lint. Cl ..A24d 01/04, A24f01/20, A24f 13/06 [58] FieldoiSearch ..13l/10.5,201,210,261B, 131/199, 204

[56] References Cited UNITED STATES PATENTS 1,719,721 7/1929 Paur ..131/199 864,076 -8/1907 Buse ..l31/199 1,005,067 10/1911 Penney ..131/210X Wood .......131/261 B UX Blount etal ..l3l/201 X Primary Examiner-Samuel Koren Assistant Examiner-J. F. Pitrelli Attorney-Pendleton, Neuman, Williams & Anderson [5 7] ABSTRACT A smoke filter is provided which is adapted to be afiixed to one end of a tobacco rod. The filter includes a first passageway through which smoke initially flows, a thin perforated membrane forming one wall of the first passageway and through which the smoke flows as a plurality of high velocity jets, and a second passageway separated from said first passageway by the perforated membrane. The second passageway has a surface against which the smoke jets impinge prior to flowing through the remainder of the second passageway. A predetermined area of a surface in the second passageway is formed of an absorptive material which is contacted by the smoke flowing through the second passageway.

10 Claims, 16 Drawing Figures PATENTED MAR28 1972 3, 651 ,8 l 9 sum 1 OF 2 PATENTED AR m2 3, 651 ,8 1 9 SHEET 2 [IF 2 SMOKE FILTER BACKGROUND OF THE INVENTION Various smoke filters for cigarettes, cigars, pipes, and the like have heretofore been provided; however, because of various design characteristics they are beset with one or more of the following shortcomings: (a) they are formed of a plurality of component parts which increase the cost of the filter and materially complicate the assembly of the filters, (b) the assembly of the filters is not compatible with the manufacturing methods and techniques employed in the cigarette-making art, and (c) the filters are ineffective in removing the liquid and/or solid particles from the smoke or in preventing the removed particles from percolating out through the downstream end of the filter.

SUMMARY OF THE INVENTION Thus, it is an object of the invention to provide a filter which avoids the shortcomings which have beset prior filters.

It is a further object of the invention to provide a filter which eliminates the need for a plug of fibrous material being positioned adjacent the downstream end ofthe filter.

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

In accordance with one embodiment of this invention, an improved smoke filter is provided which comprises first and second passageways separated from one another by a perforated membrane. The first passageway is provided with an upstream-facing open end and the second passageway is provided with a downstream-facing open end. The smoke flows from the first passageway to the second passageway through the perforated membrane in the form of high velocity jets which impinge against a passageway-forming surface. The impingement surface includes a predetermined area of absorptive material which iscontacted by the smoke as it travels through the second passageway.

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

FIG. 1 is a fragmentary enlarged longitudinal sectional view of one form ofthe improved filter.

FIG. 2 is a perspective view of the mating surface ofa complemental member of the filter of FIG. 1; said mating surface having formed therein an elongated cavity defining the second passageway.

FIG. 3 is similar to FIG. 1, but showing a second form of the improved filter.

FIG. 4 is an enlarged sectional view taken FIG. 3.

FIG. 5 is similar to FIG. 1, but showing a third form of the improved filter.

FIG. 6 is an enlarged sectional view taken along line 6-6 of FIG. 5.

FIG. 7 is a sectional view taken along line 7-7 of FIG. 5.

FIG. 8 is similar to FIG. 1, but showing a fourth form of the improved filter.

FIG. 9 is an enlarged sectional view taken along line 9--9 of F IG. 8.

FIG. 10 is a sectional view taken along line 10-10 of FIG. 8.

FIG. 11 is similar to FIG. 1, but showing a fifth form of the improved filter.

FIG. 12 is an enlarged sectional view taken 12 of FIG. 11.

FIG. 13 is a sectional view taken along line l313 of FIG. 11.

FIG. 14 is similar to FIG. 1, but showing a sixth form of the improved filter.

FIGS. 15 and 16 are sectional views taken along lines 15- I5 and l616, respectively, of FIG. 14.

Referring now to the drawings and more particularly to FIG. 1, one form of the improved smoke filter 20 is shown affixed along line 12-- along line 4-4 of to the downstream end of a tobacco rod 21. The invention will hereinafter be described with regard to a tabocco rod; however, it is to be understood, of course, that the invention is not intended to be so limited but may be utilized on cigars or incorporated in pipe stems and the like. The tobacco rod 21, in the illustrated embodiment, includes a core 22 of compacted shreds of blended tobacco which is encompassed by a sleeve 23 of conventional thin white cigarette paper.

Filter 20 includes a pair of

complemental members

24 and 25 which are formed of a suitable smoke impervious material such as foam plastic. The

members

24 and 25 may be formed by a continuous molding operation, if desired. One such molding operation is described in my pending application, Ser. No. 865,344 filed Oct. I0, 1969.

Member 24 has a substantially semi-cylindrical exterior configuration and has a substantially flat mating surface in which is formed an elongated cavity 26 having an upstreamfacing open end 26a. The cavity end 260 is in direct communication with the core -22 of the tobacco rod 21.

Member 25 also has a substantially semi-cylindrical exterior configuration and a mating surface in which is formed an elongated cavity 27 having a stepped bottom surface 28. The two

members

24 and 25, when in assembled relation, define a cylinder having a diameter which is substantially the same as the tobacco rod to which it is affixed. A raised portion 280 of the stepped bottom surface 28 is disposed adjacent the upstream end of the member. Overlying the stepped bottom surface 28 is an elongated strip 29 of absorptive material e.g., blotter paper). The strip, in the illustrated embodiment, has a width which spans the distance between a pair of shoulders 30 which delimit the side walls of the cavity. The tops 30a of the shoulders are flat and form supporting surfaces for a thin perforated membrane 31 which is disposed intermediate the mating surfaces of the

complemental members

24 and 25. The membrane 31 may be adhesively affixed to one or both of the mating surfaces.

Membrane 31 cooperates with cavity 27 to form an elongated first passageway 32 through which the smoke initially flows. The membrane 31 also cooperates with the strip 29 and the shoulders 30 to form a second passageway 33. The

passageways

32 and 33 communicate with one another only through the perforations 31a formed in the membrane 31. It is preferred that eight or more perforations be provided to effect inter-communication of the two passageways. Each of the perforations is preferably round and has a diameter of approximately 0.010 inch whereby as the smoke is drawn through the filter, the smoke enters the passageway 33 in the form of a plurality of high velocity jets. The smoke jets impinge upon the exposed surface of the strip 29 which is disposed approximately 0.015 inch from the adjacent surface of the membrane 31. The thickness of strip 29 is approximately 0.020 inch. The portion of the strip which overlies the raised portion 28a of the stepped cavity surface 28 is in direct contact with the membrane 31, see FIG. 1.

As the smoke jets impinge upon the exposed surface of strip 29, liquid and/or solid particles entrained in the smoke will become deposited thereon. Because of the absorptive characteristics of the strip, the deposited particles are retained in the strip and are prevented from percolating out the downstream end of passageway 33. Also, a second step (not shown) in surface 28, as described in my copending application Ser. No. 865,344, is sometimes preferred because the resulting increase in cross-sectional area of the passageway 27 has the effect of reducing the velocity of the smoke flowing through the downstream end. Thus, there is no need for a conventional fibrous plug to be positioned at the downstream end of a filter. The elimination of such a plug reduces the cost of the filter and facilitates the assembly thereof.

The aforedescribed components comprising the filter 20 are retained in assembled relation by an outer sleeve T of tipping paper which also serves to attach the filter to the end of the tobacco rod 21.

FIGS. 3 and 4 disclose a second form of the improved filter 34 which is similar in construction to filter 20 except that a laminated strip 35 is substituted for strip 29. Strip 35 includes a first laminate 35a of perforated nonabsorptive material which is exposed to the impinging smoke jets. The perforations 35b formed in the first laminate 35a are offset with respect to the perforations or orifices 31a formed in membrane 31. A second laminate 35c of absorptive material is secured to first laminate 35 and is exposed to the smoke passageway 33 only through the first laminate perforations 35b. Thus, with filter 34 the high velocity smoke jets initially impinge against the portions of laminate 35a intermediate the perforations 35b thereof and cause the entrained liquid and/or solid particles to be deposited thereon. As the particle deposits increase in size and tend to flow towards the downstream end of the passageway 33, they become entrapped in the laminate perforations 35b and absorbed in the absorptive laminate 356. Thus, no percolating or flow of the particles out the downstream end of passageway 33 occurs.

FIGS. 7 illustrate a third form 36 of the improved filter. In filter 36, the complemental member 24 and the cavity 26 formed therein are the same as the complemental member and cavity of filters and 34, previously described. In addition, filter 36 includes a perforated membrane 31 which is the same type as utilized in filters 20 and 34. The membrane 31 cooperates with cavity 26 to form a first passageway 32.

Filter 36 includes a second complemental member 37 which is formed of a smoke impervious material and has a substantially semi-cylindrical exterior configuration as in the case of complemental member utilized in filters 20 and 34. The mating surface 37a of member 37 is provided with an elongated cavity 38, see FIG. 7. Cavity 38 is provided with an elongated centrally disposed rib which is raised at both its upstream and

downstream ends

40a and 40b. The rib ends suportingly engage membrane 31. The central portion 40c of the rib (that is the portion intermediate the raised ends) has a flattened top surface and functions as the impingement surface for the high velocity smoke jets which flow through the membrane perforations 31a. It will be noted, in FIG. 7, that the perforations, shown in dotted lines are aligned and in registration with the central portion 40c of the rib.

Disposed to either side of rib is a

narrow channel

41 and 42 in which is positioned a strip 43 of absorptive material, see FIG. 6. The thickness of each strip 43 approximates the height of the center portion 400 of the rib. In addition to providing a support for membrane 31, the downstream end portion 40b of the rib serves as a smoke barrier causing the smoke, subsequent to impinging on rib portion 40c, to be laterally diverted so as to flow over the exposed surface of the strips 43. Thus, the strips cause the liquid and/or solid particles, which are separated from the smoke and tend to flow away from the impingement surface, to become absorbed therein and thereby prevent the deposited particles from flowing out the downstream end of the filter.

The portion 43a of each strip 43 which overlies a raised portion formed at the upstream end of each

channel

41 and 42 is in supporting contact with the perforated membrane 31. Thus, in filter 36, the smoke initially flows from the tobacco core 22 through first passageway 32 and then through the membrane perforations in the form of high velocity jets. The jets impinge against the flat top surface of rib center portion 40c causing the liquid and/or solid particles to become deposited thereon. The flow of the smoke, after impingement, is then diverted laterally so as to pass over the absorptive strips 43 and then out the downstream end of the

channel

41 or 42.

FIGS. 8-10 disclose a fourth form 44 of the improved filter. In this structure, the upper complemental member 24 and perforated membrane 31 are substantially the same as provided in the previously described filters 20, 34, and 36. A second complemental member 45 of smoke impervious material is provided which is similar to

corresponding members

25 and 37 except for the configuration of the mating surface 45a thereof. In lieu of forming a cavity in mating surface 45a, the latter is substantially planar except for a centrally disposed projection 45b formed at the upstream end of the surface, see FIGS. 8 and 10. The top of projection 45b is flat and supportingly engages membrane 31. Positioned on opposite sides of projection 45b and extending longitudinally of the mating surface 45a, are strips 46 of absorptive material. The strips serve a dual purpose (a) they absorb the liquid and/or solid particles which are deposited on the portion of the mating surface disposed intermediate the strips 46; and (b) they serve as spacers between

members

24 and 45 and thereby maintain the center portion of mating surface 45a at the proper distance (e.g., 0.012 inch) from the adjacent surface of the membrane 31. Once the

members

24 and 45, membrane 31, and strips 46 are properly assembled, an overwrap or sleeve T of tipping paper or the like is applied which retains the component parts of the filter 44 in assembled relation and affixes same to the end of a tobacco rod 21, see FIG. 8. A similar overwrap or sleeve is used with the previously described filters.

A fifth variation of the improved filter 48 is shown in FIGS. 11-13. The member 24 and the membrane 31 are the same as in the previously described

filters

20, 36, and 44. The other, or second, complemental section 50 differs from the other previously described members in the configuration of the mating surface 50a. The surface is provided with a centrally disposed channel 50b which is provided at its upstream and downstream ends with projections 50c. Overlying the channel 50b and the projections 500 is a laminated strip 51 which is substantially coextensive with the length of section 50. The upper laminate 51a is non-absorptive and is exposed to impingement by the high velocity smoke jets. The second laminate 51b is of absorptive material and is coextensive with laminate 51a. The elongated edges of the laminates are substantially straight and engage the lower opposing surfaces of the shoulders 52 which delimit the side walls of channel 50b. The portions of the strip 51 which overlie the projections 50c are in supporting engagement with membrane 31, whereas the portion of the strip which overlies the center portion of the channel 50b is spaced a predetermined distance (e.g., 0.012 inch) from the adjacent surface of the membrane 31.

The opposing side wall-forming surfaces of shoulders 52 which are adjacent the center portion of channel 50b and downstream projection 500 have the upper portions thereof recessed from the adjacent elongated edge of strip 51 and the downstream projection 50c whereas the lower portions of the shoulders, which are engaged by the strip edges, are serrated or undulated so as to form a plurality of small pockets 52a. The pockets 52a provide means whereby the smoke entrained particles which are deposited on the laminate surface 51a after the smoke jets have impinged thereagainst flow laterally into the pockets and then into the absorptive laminate 51b thereby preventing said deposited smoke particles from being discharged from the downstream end ofthe filter.

FIGS. 14-l6 show a sixth form 53 of the improved filter. As in the case of the previously described filters, filter 53 is provided with a pair of

complemental members

24 and 54. Member 24 is preferably of the same construction and configuration as member 24 previously described with respect to filter 20. Member 54, on the other hand, is provided with a pair oflongitudinally spaced, centrally aligned projections 55a and b which are disposed at opposite ends of the member. The portion of member 54 intermediate the projections 55a and b forms a recess 56. It will be noted, in FIG. 15 that the transverse dimension of projection 55b is foreshortened so that channels 570 and b are formed on either side of the projection through which the smoke flows subsequent to impinging against the portion of the absorptive strip 29 disposed within the recess 56 intermediate the projections 55a and b. The outer edge of each channel 57a and b is delimited by the outer sleeve of tipping paper T which secures the filter to the end of the tobacco rod 21.

Thus, with filter 53, the solid and/or liquid particles entrained in the smoke jets which impinge against the absorptive strip 29 are retained in the strip before the smoke continues out through the channels 57a and b. Because member 54 has no side walls which delimit the outer edges of the channels 57a and 1:, formation of the member is simplified as well as the assembly of the filter components.

It will be noted in all the aforedescribed filters, a strip of absorptive material which is substantially coextensive with the length of the member is applied to the mating surface of a member and as a result thereof, such application can be readily accomplished by the use of automatic equipment. The improved filter in all instances utilizes a minimum of component parts and does not require the use of a fibrous plug or the like and thus, the material and production costs of the filter are substantially reduced.

lclaim:

l. A smoke filter adapted to be affixed to the downstream end of a tobacco rod or the like, said filter comprising means defining a first passageway through which the smoke is adapted to initially flow, a thin perforated membrane lying in a plane parallel to the longitudinal axis of said rod through which the smoke is adapted to pass in the form ofa plurality of high velocity jets upon leaving said first passageway in a direction substantially perpendicular to said axis, and means defining a second passageway separated from said first passageway by said membrane and into which the smoke jets are adapted to flow and impinge against a surface forming a wall of said second passageway; said second passageway including a longitudinal wall surface having a predetermined area of absorptive material positioned laterally adjacent the perforations of said membrane and adapted to be contacted by the smoke while flowing through said second passageway whereby liquid and/or solid smoke-entrained particles are deposited on said absorptive material.

2. The smoke filter of claim 1 wherein said predetermined area of absorptive material comprises the impingement surface for the high velocity smoke jets.

3. The smoke filter of claim 1 wherein the membrane perforations are arranged in a longitudinally extending row.

4. The smoke filter of claim 1 wherein the predetermined area of absorptive material is offset with respect to the points of impact of the smoke jets on said wall-forming surface.

5. The smoke filter of claim 1 wherein said longitudinal wall surface is of laminated construction and includes a perforated non-absorptive first laminate against one surface of which the smoke jets are adapted to impinge and an absorptive second laminate secured to the opposite surface of said first laminate.

6. The smoke filter of claim 3 wherein said longitudinal wall surface includes an elongated narrow first strip of non-absorptive surface material coextensive and in registration with said row of perforations, and an elongated second strip of absorptive surface material adjacent to but offset with respect to said first strip.

7. The smoke filter of claim 1 including a pair of elongated substantially semi-cylindrical complemental members, each member having a mating surface, said mating surfaces being separated by said perforated membrane, one of said members being provided with an elongated first cavity having an upstream-facing open end, said cavity and membrane defining said first passageway, the second of said members being provided with an elongated second cavity having a downstreamfacing open end, said second cavity and said perforated membrane defining said second passageway, said second cavity accommodating said absorptive material.

8. The smoke filter ofclaim 7 wherein said second cavity ex tends substantially the full length of said second complemental member, said second cavity having a stepped surface configuration with a raised portion adjacent the upstream end of the member, and the stepped surface of said second cavity being overlaid by an elongated strip of absorptive material substantially coextensive therewith, the portion of said strip overlying the raised upstream end of said second cavity being in face-toface contact with said perforated membrane.

9. The smoke filter of claim 7 wherein said second cavity has a base portion and upri ht wall ortions, the latter having a substantially serrated sur ace con iguration; said cavity base portion being substantially overlaid by an elongated laminated strip, said strip comprising a non-absorptive first laminate exposed to the perforations formed in said membrane and an absorptive second laminate secured to said first laminate, said second laminate communicating with said second passageway through a plurality of recesses formed in said substantially serrated upright wall portions.

10. The smoke filter of claim 1 including a pair of complemental members formed of smoke impervious material, each member having a mating surface, said surfaces being separated by said perforated membrane, the mating surface of one of said complemental members being provided with an elongated first cavity having an upstream open end, said first cavity cooperating with said perforated membrane to form said first passageway; the mating surface of said second complemental member having a stepped configuration with a raised portion adjacent said upstream end, said second member mating surface having marginal portions thereof overlaid by a pair of spaced elongated strips of absorptive material, said strips being substantially coextensive with said stepped surface and contacting and cooperating with said perforated membrane to form said second passageway.

Claims

1. A smoke filter adapted to be affixed to the downstream end of a tobacco rod or the like, said filter comprising means defining a first passageway through which the smoke is adapted to initially flow, a thin perforated membrane lying in a plane parallel to the longitudinal axis of said rod through which the smoke is adapted to pass in the form of a plurality of high velocity jets upon leaving said first passageway in a direction substantially perpendicular to said axis, and means defining a second passageway separated from said first passageway by said membrane and into which the smoke jets are adapted to flow and impinge against a surface forming a wall of said second passageway; said second passageway including a longitudinal wall surface having a predetermined area of absorptive material positioned laterally adjacent the perforations of said membrane and adapted to be contacted by the smoke while flowing through said second passageway whereby liquid and/or solid smokeentrained particles are deposited on said absorptive material.

7. The smoke filter of claim 1 including a pair of elongated substantially semi-cylindrical complemental members, each member having a mating surface, said mating surfaces being separated by said perforated membrane, one of said members being provided with an elongated first cavity having an upstream-facing open end, said cavity and membrane defining said first passageway, the second of said members being provided with an elongated second cavity having a downstream-facing open end, said second cavity and said perforated membrane defining said second passageway, said second cavity accommodating said absorptive material.

8. The smoke filter of claim 7 wherein said second cavity extends substantially the full length of said second complemental member, said second cavity having a stepped surface configuration with a raised portion adjacent the upstream end of the member, and the stepped surface of said second cavity being overlaid by an elongated strip of absorptive material substantially coextensive therewith, the portion of said strip overlying the raised upstream end of said second cavity being in face-to-face contact with said perforated membrane.

9. The smoke filter of claim 7 wherein said second cavity has a base portion and upright wall portions, the latter having a substantially serrated surface configuration; said cavity base portion being substantially overlaid by an elongated laminated strip, said strip comprising a non-absorptive first laminate exposed to the perforations formed in said membrane and an absorptive second laminate secured to said first laminate, said second laminate communicating with said second passageway through a plurality of recesses formed in said substantially serrated upright wall portions.