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Expired Canadian patentCanada

Fault current interrupter

CA 1231167 A · Owner: General Electric Company · Inventors: Howell, Edward K.

CIPO record

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

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Abstract From the Canadian patent

A fault current interrupter is provided by the parallel combination of a positive temperature coefficient resistor and a voltage dependent resistor connected across a pair of separable contacts to permit the interruption of current without the occurrence of arcing between the contacts when the contacts first become separated. The positive temperature coefficient resistor is selected to have a relatively low resistance at room temperature and a substantially higher resistance at higher temperatures. This allows the current to transfer away from the contacts through the positive temperature coefficient resistor until the voltage across the voltage dependent resistor causes the voltage …

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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

  • Granted January 5, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 5, 2005.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledApril 4, 1985
GrantedJanuary 5, 1988
Term endedJanuary 5, 2005
Patent numberCA 1231167 A
Classification (IPC)H01H9/42 +1 more

Timeline

Timeline From CIPO dates

1986198819901992199419961998200020022004Application filedApril 4, 1985Patent grantedJan 5, 1988Term endedJan 5, 2005

Sources & verification

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