Improved electrode for high current density plasma arc torch
CA 2136203 C · Owner: Sanders, Nicholas A. · Inventors: Sobr, John; Luo, Lifeng; Sanders, Nicholas A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The diameter of a hafnium insert (44) press fit into the bottom end of a copper electrode (42) varies as a function of the level of a current carried by the electrode. The diameter is the minimum necessary to support emission at that currentlevel while also protecting the copper body against attack by the arc. The insert (44) is generally circular and preferably extends completely through the bottom wall (42g) to a circulating flow of cooling water at a hollow interior (48) of the electrode. The bottom wall includes an annular recess (42d) in a portion of the copper wallsurrounding the insert. A coolant tube (56) extends into the recess in a spaced relationship to provide a high flow …
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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
- Filed April 30, 1993 and granted May 20, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 30, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 30, 2015.
- 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.