Canadian application, no grantCanada
Cigarette filter rod elements and cigarettes incorporating such filter rod elements
CA 2000428 A1 · Owner: Liew, Tow P. · Inventors: Brackmann, Warren Arthur; Liew, Tow P.
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A cigarette filter rod element incuding an axially extending barrier tube of micro-fine fibres with a diameter of between 0.5 and 10 microns and located so that at least part of the gas flow passes through the wall of said barrier tube.
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
- Filed October 11, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 11, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 11, 2011.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledOctober 11, 1989
GrantedNo grant recorded
Term endedOctober 11, 2009
Patent numberCA 2000428 A1
Classification (IPC)A24D3/04
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.