Method for replacing buried pipe
CA 2226979 C · Owner: Nowak Construction Co. Inc. · Inventors: Nowak, John G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of replacing an existing buried pipe (1) with a replacement pipe comprising the steps of positioning a drilling unit (35) over the pipe to be replaced, operating the drilling unit to drive and guide a flexible drill stem (40) through the earth into an open end of the pipe to be replaced further , operating the drilling unit to extend the drill stem through the pipe to be replaced, attaching to the leading end of the drill stem a conical back reaming bit (45), attaching to the trailing end of the back reaming bit a flexible replacement pipe, and operating the drilling unit to apply a pulling force and rotational torque to the drill stem causing the back reaming bit to , be …
Read the whole patent
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 July 17, 1996 and granted February 6, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 17, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 17, 2018.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.