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Expired Canadian patentCanada

Arrangement for cleaning internal surface of casing strings

CA 1291946 C · Owner: Ledyashov, Oleg A. · Inventors: Petrov, Stanislav F.; Goryainov, Stanislav P.; Ledyashov, Oleg A.

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

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Abstract From the Canadian patent

An arrangement for cleaning the internal surface of casing strings, comprises a hollow cylindrical body with slots provided around the periphery thereof. The slots accommodate extendable cutting blades. The cutting blades are moved with the aid of walls of an elastic vessel. The elastic vessel is disposed inside the body and adapted to be communicated with a source of compressed fluid medium. The elastic vessel is disposed in a bushing installed coaxially with the body and provided with longitudinal ports. The ports are arranged opposite to the slots of the body and are equipped with flat spring elements. The flat spring elements substantially completely cover the ports of the bushing and …

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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 12, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 12, 2008.
  • 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 14, 1987
GrantedNovember 12, 1991
Term endedNovember 12, 2008
Patent numberCA 1291946 C
Classification (IPC)E21B37/02

Timeline

Timeline From CIPO dates

1988199119941997200020032006Application filedDec 14, 1987Patent grantedNov 12, 1991Term endedNov 12, 2008

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