Filter, smoking articles containing the same, filter strands and methods and devices for producing filters and smoking articles of this type
The invention relates to a filter ( 10 ) for tobacco products with a first terminal filter element ( 12 ), a second terminal filter element ( 14 ), a middle filter element ( 16 ) which is located between first and second terminal filter element and contains a granular filter material, and a casing ( 20 ), one part of one of the terminal filter elements ( 12 ) being displaceable vis-à-vis the casing ( 20 ). The invention furthermore relates to smoking articles with such filters, filter strands with two or more of the filters, and processes and devices for the production of such filters and tobacco products.
1. A process for producing a filter strand ( 31 ) comprising two or more filters ( 10 ) each including a first end filter element ( 12 , 24 , 26 ), a second inside filter element ( 14 ), a middle filter element ( 16 ) containing granular filter material ( 17 ) and located between the first and second filter elements, and an outside casing ( 20 ) surrounding all of the filter elements, the process comprising the steps of exerting force on the first end filter element ( 12 , 24 , 26 ) from outside the filter strand ( 31 ) in order to inwardly displace at least a portion of the first end filter element ( 12 , 24 , 26 ) relative to the casing ( 20 ) toward and against the middle filter element ( 16 ), to thereby compress the granular filter material ( 17 ) therein, and wherein each first end filter element ( 12 , 24 , 26 ) includes an outer ring ( 24 ) and an internal core ( 25 ), and wherein the internal core ( 25 ) is displaced inwardly against the granular filter material ( 17 ).
2. A process for producing a filter strand ( 31 ) comprising two or more filters ( 10 ) each including a first end filter element ( 12 , 24 , 26 ), a second inside filter element ( 14 ), a middle filter element ( 16 ) containing granular filter material ( 17 ) and located between the first and second filter elements, and an outside casing ( 20 ) surrounding all of the filter elements, the process comprising the steps of exerting force on the first end filter element ( 12 , 24 , 26 ) from outside the filter strand ( 31 ) in order to inwardly displace at least a portion of the first end filter element ( 12 , 24 , 26 ) relative to the casing ( 20 ) toward and against the middle filter element ( 16 ) to thereby compress the granular filter material ( 17 ) therein, and wherein each first filter end element ( 12 , 24 , 26 ) includes at least two pieces ( 12 , 26 ) one of which is displaced inwardly against the granular filter material ( 17 ).
3. A process as in claim 1 including the step of preventing return of the inwardly displaced portion of the first filter element ( 12 , 24 , 26 ) after inward displacement thereof through friction and interference between the outer ring and the inner core.
4. A process as in claim 2 including the step of preventing return of the inwardly displaced portion of the first filter element ( 12 , 24 , 26 ) after inward displacement thereof through friction and interference between the two pieces.