Trenchless pipeline replacement
CA 2123298 C · Owner: Trenchless Replacement Services Ltd. · Inventors: Handford, Reginald 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 underground pipe (44) with a new pipe (48) comprises the steps of moving a pipe removing tool (70) along the existing pipe (44) to remove the exiting pipe and dragging the new pipe (48) behind the tool (70) to replace the existing pipe while imparting vibratory motion to the tool (70) or continuously applying a dressing material ahead of the new pipe to act as lubricant or to fill in the annular space between the new pipe and the surrounding soil. According to another embodiment, the method comprises the steps of pushing out the old pipe (126) in one direction by means of a pipe removing tool (110) connected to a hydraulic unit (10) through a stem and …
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 November 13, 1991 and granted January 23, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 13, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 13, 2013.
- 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.