Tobacco smoke filter (semi-circles)
CA 1049878 A · Owner: American Filtrona Corporation · Inventors: Berger, Richard M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Tobacco smoke filters and methods and means for making same wherein the products have a composite substantially cylindrical inner member formed from two semi-cylindrical inner elements and overwrapped with a common plug wrap. The composite inner member has a discrete inner cavity formed in each semi-cylindrical element and a composite cavity formed by a depressed portion in each semi-cylindrical element. A substantially smooth outer surface is provided on the composite inner member for attaching a conventional plug wrap without the need for an internal glue line. Separate cylindrical elements are reformed into semi-cylindrical elements and crimped to provide depressed pockets following, …
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 March 6, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 6, 1996.
- 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.