Expired Canadian patentCanada
Process of refining woodpulp
CA 191609 A · Owner: Drewsen, Viggo · Inventors: Drewsen, Viggo
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordRead 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 July 15, 1919. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 15, 1936.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJune 26, 1918
GrantedJuly 15, 1919
Term endedJuly 15, 1936
Patent numberCA 191609 A
Classification (IPC)—
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.