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Expired Canadian patentCanada

Telephone system

CA 177357 A · Owner: Gressinger, Elwood · Inventors: Gressinger, Elwood

CIPO record

Overview

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

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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.

Google PatentsCIPO record

Why it's free to use

  • Granted May 29, 1917. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 29, 1934.
  • 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 9, 1917
GrantedMay 29, 1917
Term endedMay 29, 1934
Patent numberCA 177357 A
Classification (IPC)—

Timeline

Timeline From CIPO dates

191819201922192419261928193019321934Application filedMarch 9, 1917Patent grantedMay 29, 1917Term endedMay 29, 1934

Sources & verification

Official CIPO records

Canadian Patents DatabaseClaims, description, documents and status.CIPO

Cross-check elsewhere

Google PatentsFull text, worldwide family, citing patents and legal events.patents.google.com

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