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Expired Canadian patentCanada

Vacuum switch apparatus

CA 2011644 C · Owner: Kurosawa, Yukio · Inventors: Suzuki, Kouzi; Arita, Hiroshi; Kurosawa, Yukio

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 vacuum switch apparatus has an electrically insulating vacuum enclosure which is evacuated to a vacuum degree of 2 x 10-2 Torr or less. One set of anode and cathode electrodes is arranged in the vacuum enclosure, having capacity which permits the flow of a discharge current of at least 1 KA therebetween and being operable to switch the discharge current at least 106 shots. A high voltage power supply applies a high voltage of at least 20 KV across the anode and cathode electrodes. An electron beam irradiation unit irradiates an electron beam on the anode electrode through the cathode electrode. A control electrode is arranged between the beam irradiation unit and the cathode electrode, …

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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 March 7, 1990 and granted February 20, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 7, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 7, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMarch 7, 1990
GrantedFebruary 20, 1996
Term endedMarch 7, 2010
Patent numberCA 2011644 C
Classification (IPC)H01J29/46 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedMarch 7, 1990Patent grantedFeb 20, 1996Term endedMarch 7, 2010

Sources & verification

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