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Expired Canadian patentCanada

Polarity switch for step-transformer selector

CA 2085029 C · Owner: Freymuller, Heinrich · Inventors: Freymuller, Heinrich

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 step-transformer selector has a generally cylindrical drum centered on an axis and provided with an annular array of selector contacts and, axially offset therefrom with at least one polarity, contact offset axially from the selector contacts. A selector shaft extends along the axis in the drum and rotatable about the axis to connect to selected ones of the selector contacts. A polarity switch having a pivot in the drum offset from the axis and a rang can rock in the drum on the pivot between a connecting position touching and connecting to the polarity contact and an out-of-service position offset from and out of contact with the polarity contact. A cam on the shaft engages a follower on …

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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 December 10, 1992 and granted October 29, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 10, 2012.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 10, 2014.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 10, 1992
GrantedOctober 29, 2002
Term endedDecember 10, 2012
Patent numberCA 2085029 C
Classification (IPC)H01H21/18 +2 more

Timeline

Timeline From CIPO dates

1993199519971999200120032005200720092011Application filedDec 10, 1992Patent grantedOct 29, 2002Term endedDec 10, 2012

Sources & verification

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