Tobacco smoke filter and method
CA 1077368 A · Owner: Liggett And Myers Incorporated · Inventors: Van Hall, Floyd
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to a cigarette filter composed of two concentric cylindrical layers of fibrous filter materials, in which the inner cylindrical layer has a lower draw resistance than the outer cylindrical layer, and a method and apparatus for the manufacture thereof.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted May 13, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 13, 1997.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.