Improved lightning protection for field mounted instruments
CA 2113419 A1 · Owner: Rosemount Inc. · Inventors: Longsdorf, Randy J.; Nelson, Richard L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A protection circuit is provided for protecting sensitive electrical field instruments from a transient voltage strike and for ensuring that the instruments will meet safety approval during high potential voltage testing. The first and second wires of a two-wire circuit are connected to a first and second terminal respectively. A first surge arrestor electrically couples a first path between the first and second terminal. An impedance and a transient suppresor are connected in series and electrically couple a second path between the first and second terminal. The second path is coupled in parallel with the first path between the first and second terminal and is coupled closer to the …
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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 August 7, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 7, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 7, 2014.
- 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.