Control of staged heating and cooling apparatus by a four-wire thermostat
CA 2032874 C · Owner: Emerson Electric Co. · Inventors: Brown, Bernard T.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A heating and cooling apparatus wherein either or both the heating apparatus and cooling apparatus are two-stage is controlled by a thermostat through four connecting wires. A signal on one of the wires enables the functions of controlling operation of the circulator fan and controlling second-stage operation of whichever apparatus is two-stage.
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 20, 1990 and granted July 13, 1993. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 20, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 20, 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.