Electronic control system for a gas-fired/hot air furnace with induced draft blower
CA 2003235 A1 · Owner: Williams, Roger W. Jr. · Inventors: Williams, Roger W. Jr.; Williams, Roger W. Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Electronic control system for a gas-fired/hot air furnace includes a primary control unit which controls the flow of fuel to the furnace. The furnace has heating and cooling space thermostats and a comfort fan to supply heated or cooled air to the space being monitored by the thermostats and an induced draft blower which supplies combustion air into the furnace for heating. A first switch and associated relay drive selectively energizes the comfort fan for low speed heating operation and a second relay switch and associated relay drive selectively energizes the comfort fan for high speed cooling operation. Actuation of the heating thermostat energizes a third switch and associated relay …
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 17, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 17, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 17, 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.