Expired Canadian patentCanada
Weight element electric light and power plants
CA 284875 A · Owner: John H. Doak · Inventors: John H. Doak
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 November 20, 1928. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 20, 1945.
- 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—
GrantedNovember 20, 1928
Term endedNovember 20, 1945
Patent numberCA 284875 A
Classification (IPC)F03G3/00
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.