Claims
- 1. In a method of producing cigarette filter units in which portions of fibrous filter material and of pourable filter material are serially disposed, the steps comprising:
- arranging a series of fibrous filter portions at substantially uniform spaced apart intervals on a sheathing strip of substantially constant width equal to between 75% and 93% of the filter portion circumference,
- forming a continuous strand of filter portions by wrapping the sheathing strip around said series of said fibrous portions including the spaces therebetween and attaching said strip to said fibrous portions so as to define successive empty chambers between said fibrous portions and filler slots of substantially constant width extending the length of said chambers,
- conveying said strand under a suction zone having lateral walls, the undersides of which are in sealing and sliding relationship with the outsides of the two side edges of said sheathing strip, so that the said two side edges of said sheathing strip which define the filler slots, also define a suction slot along the length of said strand,
- evacuating air from each successive, in closed-off state, empty chamber of said strand by continuously applying suction to said chambers being in closed-off state through said suction slot,
- transferring said strand in closed-off state to a filling zone containing dispensable pourable filter material, the filling zone having lateral walls, the undersides of which are in sealing and sliding relationship with the outside of the two side edges of said sheathing strip, so that the chambers in said strand are maintained in closed-off state under reduced pressure until said chambers reach said filling zone and so that said filler slots pass beneath a filling port containing said pourable filter material where each of said evacuated chambers is opened to said filling port;
- filling said chambers with said pourable filter material, said pourable filter material being drawn into said chambers through said filler slots due to the reduced pressure in said chambers, and
- sealing said suction slot with a sealing strip which is only slightly wider than the width thereof.
- 2. A method as claimed in claim 1, wherein each filter unit has a predetermined length, wherein said sheathing and sealing strips are transparent and wherein the step of sealing is performed so that the transparency of said sheathing and sealing strips is preserved along the entire length of said filter unit.
- 3. A method as claimed in claim 2, wherein the face of the sheathing and/or sealing strip whose side is in contact with the filter elements, is coated with thermoplastic material, and the strip or strips are secured by heating the thermoplastic material.
- 4. A method as claimed in claim 2, wherein prior to filling the spaces with pourable material, the sheathing strip is adhesively fixed to the fibrous portions, thus accurately defining the diameter of the cigarette filter unit which is to be produced.
- 5. A method as claimed in claim 2, and the further step comprising clearing the exposed areas of the fibrous filter portions between the two side edges of the sheathing strip and said two side edges of the sheathing strip of pourable material disposed in these regions after filling said chambers but before applying said sealing strip.
- 6. A method as claimed in claim 2, wherein a reduced pressure of at least 3 cm Hg is produced in the chambers which are to be filled.
- 7. A method as claimed in claim 2, wherein at least part of the pourable filter material includes a composition which will discolor under the influence of specific smoke constituents which are a health hazard for the smoker.
- 8. A method as claimed in claim 7, wherein said composition has the capacity to absorb such constituents.
- 9. A method as claimed in claim 2, wherein the pourable material is granular activated carbon which is colored or has a chemically non-injurious colored coating.
- 10. A method as claimed in claim 7, wherein the pourable material is friable filter material which contains an acid-base indicator which undergoes a color change under the influence of an acid or a base.
- 11. A method as claimed in claim 2, wherein the pourable material is a friable filter material which contains or consists of an oxidation catalyst which serves to oxidize carbon monoxide to carbon dioxide.
- 12. A method as claimed in claim 11, wherein anhydrous manganese dioxide is used as the oxidation catalyst.
- 13. A method according to claim 12, wherein the anhydrous manganese dioxide is mixed with 3 to 12% copper nitrate and/or 4 to 14% silver nitrate.
- 14. A method as claimed in claim 2, wherein the reduction of pressure is carried out by a suction device arranged in a passage which has a seal for sealing with the filter units so that the vacuum in the chambers is not lost as the units pass from the suction device to the filling zone, and wherein the length of the seal is greater than the length of the spaces between the fibrous portions.
- 15. A method as claimed in claim 14, wherein two different kinds of fibrous filter portions with different axial flow resistances are alternatively arranged in the sheathing strip, and the length of the seal as seen in the direction of movement of the sheathing strip amounts to at least 2a+2b+2c, where a is the length of one kind of filter portion, b is the length of the other kind of filter portion, and c is the length of the space between the portions, and wherein said suction device defines a port positioned half way along the length of the seal.
- 16. A method as claimed in claim 15, wherein the length of the suction region is less than the length of the smaller of the filter portions in use.
- 17. A method as claimed in claim 7, wherein said composition is capable of combining chemically with said smoke constituents.
- 18. A method as claimed in claim 7, wherein said composition is also capable of converting said specific smoke constituents into constituents which are innocuous to health.
- 19. A cigarette filter unit produced by the method according to claim 2.
- 20. An apparatus for producing cigarette filter units in which portions of fibrous filter material and of pourable filter material are alternately disposed comprising, in a continuous production line,
- means for aligning and uniformly spacing a series of fibrous filter portions,
- a conveyor for feeding on one side of said fibrous portions a continuous filter sheathing strip of substantially constant width equal to between 75% and 93% of the circumference of said filter portions,
- wrapping means for wrapping said sheathing strip around the series of said fibrous portions so as to form a continuous cylindrical strand with empty chambers between adjacent fibrous portions and filler slots extending the length of said chambers defined by the two side edges of said sheathing strip,
- a continuous suction zone having lateral walls the length of said strand in sealing and sliding relationship to the other surface of said sheathing strip and forming a suction slot of substantially constant width defined by the two side edges of said sheathing strip and said lateral walls, and suction means for reducing the pressure in said chambers through said suction slot,
- a filling zone containing dispensable pourable filter material,
- conveying means for transporting said strand from said suction means to said filling zone,
- sealing means for maintaining the reduced pressure in said chambers while said strand is transferred from said suction means to said filling zone, so that said chambers open in said filling zone under reduced pressure causing said dispensable pourable filter material to be sucked into said chambers through said filler slots, and
- means for applying to said strand a sealing strip which is only slightly larger than the width of said suction slot to seal said strand.
- 21. An apparatus as claimed in claim 20, wherein said sheathing and sealing strips are transparent and wherein the means for applying said sealing strip preserves the transparency of said sheathing and sealing strips along the entire length of said filter unit.
- 22. Apparatus as claimed in claim 21, wherein the suction means has a plurality of ports opening into the suction zone and connected to a source of reduced pressure.
- 23. Apparatus as claimed in claim 21, and further including a brush between the filling zone and the sealing means for removing pourable filter material from the surfaces of the filter units which are free of the sheathing strip, and from surfaces which are associated with the sheathing strip and define the suction slot.
- 24. Apparatus as claimed in claim 21, wherein the brush is associated with an extraction device, for extracting the removed pourable material.
- 25. Apparatus according to claim 21, in which said suction zone and said filling zone are joined to each other through a common surface which has a slidable and sealable relationship to the exposed top sides of the filter portions not covered by said sheathing strip and wherein the suction slot is defined by lateral surfaces and the lateral edges of the sheathing strip.
- 26. Apparatus according to claim 21, which further comprises means for arranging alternately two different kinds of filter elements having different axial flow resistances on said sheathing strip and wherein the length of lateral surface in slidable relationship with said sheathing strip in the direction of movement of said sheathing strip amounts to at least 2a+2b+2c where a is the length of one kind of filter element, b is the length of the other kind of filter element and c is the length of said chamber and wherein ports of the suction device are positioned halfway along the length of said lateral surface.
- 27. A cigarette filter comprising portions of fibrous filter material and of pourable filter material serially disposed and produced by the steps of:
- arranging a series of fibrous filter portions at substantially uniform spaced apart intervals on a sheathing strip of substantially constant width equal to between 75% and 93% of the filter portion circumference,
- forming a continuous strand of filter portions by wrapping the sheathing strip around said series of said fibrous portions including the spaces therebetween and attaching said strip to said fibrous portions so as to define successive empty chambers between said fibrous portions and filler slots of substantially constant width exceeding the length of said chambers,
- conveying said strand to a suction zone having lateral walls in sealing and sliding relationship with the outside of said sheathing strip, so that said walls, together with the two side edges of said sheathing strip which define the filler slots also define a suction slot along the length of said strand,
- reducing the pressure in the empty chambers of said strand by continuously applying suction to said strand through said suction slot,
- transferring said strand directly to a filling zone containing dispensable pourable filter material so that the chambers in said strand are maintained under reduced pressure until said strand reaches said filling zone and so that said filler slot pass beneath a filling port containing said pourable filter material,
- filling said chambers with said pourable filter material said pourable filter material being drawn into said chambers through said filler slots due to the reduced pressure in said chambers,
- successively releasing the reduced pressure in said chambers upon a respective chamber of said chambers reaching said filling zone, and
- sealing said suction slot with a sealing strip which is only slightly wider than the width thereof.
- 28. A cigarette filter according to claim 27, wherein said sheathing and sealing strips are transparent and wherein the means for applying said sealing strip preserves the transparency of said sheathing and sealing strips along the entire length of said filter unit.
- 29. In a method of producing cigarette filter units in which portions of fibrous filter material and of pourable filter material are serially disposed, the steps comprising:
- arranging a series of fibrous filter portions at substantially uniform spaced apart intervals on a sheathing strip of substantially constant width equal to between 75% and 93% of the filter portion circumference, said sheathing strip having two outside edges,
- forming a continuous strand of filter portions by wrapping the sheathing strip around said series of said fibrous portions including the spaces therebetween and attaching said strip to said fibrous portions so as to define successive empty chambers between said fibrous portions and filler slots of substantially constant width extending the length of said chambers, each chamber having a closed-off state,
- conveying said strand near one side of a suction zone having lateral walls in sealing and sliding relationship with the outside edges of said sheathing strip, so that said walls, together with the two edges of said sheathing strip which define the filler slots, also define a suction slot along the length of said strand,
- reducing the pressure in each successive empty chamber of said strand by continuously applying suction to said strand through said suction slot, each of said empty chambers being in the closed-off state,
- transferring said strand and its chambers in their closed-off state directly to a filling zone containing dispensable pourable filter material, the filling zone including side walls having extremities in sealing and sliding relationship with the outside edges of said sealing strip, so that the chambers in said strand are maintained under reduced pressure in the closed-off state, until the chambers of said strand reach said filling zone, and so that said filler slots pass, and are juxtaposed to a filling port containing said pourable filter material,
- opening each of the chambers towards the filling port upon being juxtaposed thereto, so as to successively change the closed-off state of each chamber to an open state,
- filling said chambers with said pourable filter material, said pourable filter material being drawn into said chambers through said filler slots due to the reduced pressure in said chambers, and
- sealing said suction slot with a sealing strip which is only slightly wider than the width thereof.
- 30. In a method as claimed in claim 29, wherein said sealing and sheathing strips are transparent and wherein the step of sealing is pre-formed so that the transparency of said sheathing and sealing strips is preserved along the entire filter unit.
Priority Claims (2)
Number |
Date |
Country |
Kind |
15905/75 |
Dec 1975 |
CHX |
|
14907/76 |
Nov 1976 |
CHX |
|
Parent Case Info
This is a continuation, of application Ser. No. 748,500, filed Dec. 8, 1976, now abandoned.
US Referenced Citations (4)
Continuations (1)
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Number |
Date |
Country |
Parent |
748500 |
Dec 1976 |
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