Electrical contact avoidance device
CA 2086640 C · Owner: Hanrahan, Robert C. · Inventors: Williamson, James; Hanrahan, Robert C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An electrical contact avoidance device comprises an inductor plate directly or capacitively coupled to the user and coupled to a detector circuit which derives a DC signal corresponding to a voltage induced in the user's body by a radiated high voltage electrostatic field. A comparator compares the DC signal with a reference signal representing the potential difference between the inductor and reference plates, and activates an alarm if the detected signal exceeds a preselected reference level.
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 January 4, 1993 and granted May 19, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 4, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 4, 2015.
- 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.