Expired Canadian patentCanada
Thermionic valve circuit
CA 380654 A · Owner: Electric And Musical Industries Limited · Inventors: Rupert Ivor Kinross; Walter John Brown
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 11, 1939. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 11, 1956.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Filed—
GrantedApril 11, 1939
Term endedApril 11, 1956
Patent numberCA 380654 A
Classification (IPC)H04B1/26
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.