Variable speed warning device
CA 2197300 C · Owner: Federal Signal Corporation · Inventors: Graham, Paul D.; Gibb, Richard G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Method and apparatus for increasing the effectiveness of emergency signalling devices on vehicles. An emergency signalling device such as a flashing light is repeatedly operated at a frequency rate that corresponds to the speed of the vehicle. A minimum repetition rate is employed when the vehicle is slow or stopped so that the signal is not similarly halted and a maximum rate is , employed above a certain speed so that the repetition rate is not at too high of a frequency to be perceived.
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 August 24, 1995 and granted April 11, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 24, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 24, 2017.
- 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.