Expired Canadian patentCanada
Percussion rock drills
CA 515357 A · Owner: Ernest Craig · Inventors: Ernest Craig
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 9, 1955. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 9, 1972.
- 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 9, 1955
Term endedAugust 9, 1972
Patent numberCA 515357 A
Classification (IPC)E21B1/38
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.