Expired Canadian patentCanada
Method of induction preheating
CA 839944 A · Owner: Northern Electric Company Limited · Inventors: Thornton, Clifford J.; Colton, Douglas R.
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 April 21, 1970. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 21, 1987.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 15, 1966
GrantedApril 21, 1970
Term endedApril 21, 1987
Patent numberCA 839944 A
Classification (IPC)B01D17/09 +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.