Process for making internally hardened tubes
CA 1265420 C · Owner: Bear, William H. · Inventors: Bear, William H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
PROCESS FOR MAKING INTERNALLY HARDENED TUBES" ABSTRACT OF THE DISCLOSURE, The present invention relates to a process for hardening the interior surface of a long, thin-walled small inside diameter, tubular member, such as a tube which would be used to form a downhole pump barrel. More particularly, it relates to a process involving progressive heating with an internally positioned electro-magnetic, induction coil, followed by immediate quenching with a quench ring assembly, to develop a martensitic case on the inner surface of the tube. The invention further extends to the apparatus utilized in conducting the process, and to the product tube itself.
Read 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 6, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 6, 2007.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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.