Expired Canadian patentCanada
Pleated paper filter cartridge
CA 1089777 A · Owner: Donaldson Company, Inc. · Inventors: Durre, Reynold F.; Berven, Richard 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 filter including a resilient frame a hollow body of, pleated paper, and end closures molded together to make a, flexible unitary structure which maintains its shape and has the efficiency characteristics of the paper medium.
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 November 18, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 18, 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.
FiledMay 16, 1978
GrantedNovember 18, 1980
Term endedNovember 18, 1997
Patent numberCA 1089777 A
Classification (IPC)B01D46/24 +2 more
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.