Expired Canadian patentCanada
Brick for improved service life in certain ferruginous environments
CA 781972 A · Owner: Harbison-Walker Refractories Company · Inventors: Jack L. Cunningham; Roger Snellman
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 2, 1968. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 2, 1985.
- 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 2, 1968
Term endedApril 2, 1985
Patent numberCA 781972 A
Classification (IPC)C04B35/52
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.