Apparatus and method for improved pipe to manhole sealing
CA 2004749 C · Owner: Npc Inc. · Inventors: Gundy, William P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A system and apparatus for sealably and flexibly joining a pipe member and an enclosed body formed with a port hole defined by a circular edge including a seal comprising a double-walled elastic sleeve with an annular cavity. The cavity contains a dry, liquid-activated coagulant material that forms a cellular gelatinous mass that fills the cavity and supports the sleeve when activated with water. When the seal is properly positioned water is pumped under pressure through a valve into the cavity to expand the elastic sleeve and to seal the engagement with the pipe and the body having a port hole. Over time the water and, coagulant material form a gel that remains in a viscous state 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 December 6, 1989 and granted May 23, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 6, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 6, 2011.
- 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.