Expired Canadian patentCanada
Lens grinding apparatus
CA 216232 A · Owner: The American Optical Company · Inventors: Harry W. Hill
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 February 28, 1922. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 28, 1939.
- 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—
GrantedFebruary 28, 1922
Term endedFebruary 28, 1939
Patent numberCA 216232 A
Classification (IPC)B23Q
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.