Flue control device
CA 2011602 C · Owner: Hagan, Grant Everett · Inventors: Hagan, Grant Everett
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A device for adjustably restricting the flow of exhaust gases in a furnace flue to conserve fuel is disclosed. It comprises two interlocking pipe sections and a helical element having one end fixed to the inner surface of each pipe section. The helical element has a circular opening along its central axis. The degree of restriction provided by the device is adjusted by twisting or separating the two pipe sections.
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 March 6, 1990 and granted September 3, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 6, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 6, 2012.
- 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.