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Expired Canadian patentCanada

Prelubricated innerduct

CA 1310813 C · Owner: Shoffner, John · Inventors: Shoffner, John

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

An innerduct is disclosed which can fit inside a preexisting conduit and extend along the length thereof or can be directly buried with a plow or in an open trench, for receiving transmission cables and, in particular, fiber optic cables. The innerduct is formed by coextruding first and second materials, the material for the inner portion of the innerduct including a lubricous material impregnated therein so that friction is reduced between the inner surface of the interduct and cables which are pulled therethrough. Ribs can be provided on the inner and outer surfaces of the innerduct or the duct can be formed with undulated walls so as to further reduce friction between same and cables …

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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 December 1, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 1, 2009.
  • 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 2, 1988
GrantedDecember 1, 1992
Term endedDecember 1, 2009
Patent numberCA 1310813 C
Classification (IPC)F16L1/00 +2 more

Timeline

Timeline From CIPO dates

1989199219951998200120042007Application filedMarch 2, 1988Patent grantedDec 1, 1992Term endedDec 1, 2009

Sources & verification

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