Internal combustion engine having oxygen sensor with reference criterion calibration
CA 2175295 C · Owner: Bg Plc · Inventors: Tebbutt, Iain John
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An internal combustion engine has an engine unit fuelled by fuel gas through a carburettor and also an exhaust pipe comprising a catalytic converter and an oxygen sensor or lambda cell of zirconia incorporating a platinum electrical resistance heater in a bridge circuit having a control resistance and fixed resistances. For calibration the cell is initially operated in atmospheric air with an heater power control circuit supplying variable d.c. power output, under control of a microcontroller, to the bridge to power the heater and vary the temperature of the cell. When the cell gives an electrical output of a predetermined reference value this is, observed by the microcontroller which …
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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 April 29, 1996 and granted April 25, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 29, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 29, 2018.
- 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.