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Expired Canadian patentCanada

Static electric discharge for dust collector

CA 2055669 C · Owner: Berfield, Robert C. · Inventors: Berfield, Robert C.

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

An anti-static dust collector includes a tank and an electrically non-conductive flexible hose both of which are susceptible to the build-up of static electric charge. To remove such charge from the hose the hose includes a helical wire which is connected to the grounding terminal of the electrical power plug used to supply electric power to the dust collector. Where the housing of the vacuum cleaner is electrically non-conductive, accumulation of electrostatic charge from the housing is removed by a metallic strap connected to the interior of the housing and also electrically connected to the grounding terminal of the power plug.

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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 15, 1991 and granted April 18, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 15, 2011.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 15, 2013.
  • 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 15, 1991
GrantedApril 18, 2000
Term endedNovember 15, 2011
Patent numberCA 2055669 C
Classification (IPC)H05F3/02 +2 more

Timeline

Timeline From CIPO dates

1992199419961998200020022004200620082010Application filedNov 15, 1991Patent grantedApril 18, 2000Term endedNov 15, 2011

Sources & verification

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