Expired Canadian patentCanada
Chalk board with guide lines and method of making same
CA 878616 A · Owner: The Enamel Products Company · Inventors: George C. Johnson, Jr.
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 August 17, 1971. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 17, 1988.
- 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—
GrantedAugust 17, 1971
Term endedAugust 17, 1988
Patent numberCA 878616 A
Classification (IPC)B43L1/00
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.