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Expired Canadian patentCanada

Plasma torch

CA 2174317 C · Owner: Kitahashi, Masamitsu · Inventors: Kurokawa, Iwao; Kitahashi, Masamitsu; Minonishi, Mikio

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A plasma torch of swirling plasma gas flow type is disclosed in which there are provided an electrode body having a forward end thereof and a nozzle that is arranged to enclose said forward end portion of the electrode and that is spaced therefrom across a plasma gas flow passage, characterized in that at least a portion of the said electrode body at which a pilot arc can be ignited is composed of either of a material that is high in its melting point and a mixture of the said high melting point material with either of a substance that is low in its work function and an oxide of the said substance.

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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 November 2, 1994 and granted January 11, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 2, 2014.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 2, 2016.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledNovember 2, 1994
GrantedJanuary 11, 2000
Term endedNovember 2, 2014
Patent numberCA 2174317 C
Classification (IPC)B23K10/00 +2 more

Timeline

Timeline From CIPO dates

1995199719992001200320052007200920112013Application filedNov 2, 1994Patent grantedJan 11, 2000Term endedNov 2, 2014

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.