Safety device and method
CA 2035682 C · Owner: Pelkey, Mark J. · Inventors: Pelkey, Mark J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a gas pressure safety device used in the natural gas distribution systems leading to homes or other customers. This safety device is connected to a gas venting device that allows excess gas to exit therefrom. The safety device is made up of a needle valve, a pressure sensing pilot and a spring-diaphragm actuator. The needle valve is used to restrict the rate of gas flow into the actuator to a rate less than that that can be vented by the pressure sensing pilot. When an excess pressure is generated in the distribution system the pressure sensing pilot senses when to exhaust the excess gas through the actuator and out of the gas venting device to the atmosphere.
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 February 5, 1991 and granted December 17, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 5, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 5, 2013.
- 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.