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Expired Canadian patentCanada

Contact lens casting method

CA 1112821 A · Owner: Novartis Pharma Canada Inc./Novartis Pharma Canada Inc. · Inventors: Travnicek, Edward A.

CIPO record

Overview

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

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Abstract From the Canadian patent

Producing from a single contact lens casting mold lenses, of a number of different sizes by including in the casting precursor for each lens, a controlled amount of an extractable diluent of low volatility which is extracted after casting to cause the resulting lens to shrink a calculable amount. Variations in amounts are used to produce corresponding variations in sizes of cast and extracted lenses.

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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 November 24, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 24, 1998.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledSeptember 20, 1978
GrantedNovember 24, 1981
Term endedNovember 24, 1998
Patent numberCA 1112821 A
Classification (IPC)B29D11/00

Timeline

Timeline From CIPO dates

1979198119831985198719891991199319951997Application filedSep 20, 1978Patent grantedNov 24, 1981Term endedNov 24, 1998

Sources & verification

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