Freight brake emergency valve
CA 2005296 C · Owner: Hart, James E. · Inventors: Hill, Theodore B.; Gaughan, Edward W.; Hart, James E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved freight brake emergency valve device providing improved stability against undesired emergency brake applications without degradation of emergency sensitivity. This is achieved, in one aspect of the invention, by introducing a spring force on the emergency piston as the piston approaches emergency position to thereby retard the piston momentum sufficiently to allow a random brake pipe pressure fluctuation to dissipate. In another aspect of the invention, a choke and check valve are arranged to create a dashpot effect to retard piston momentum resulting from a random brake pipe pressure fluctuation.
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 December 12, 1989 and granted January 9, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 12, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 12, 2011.
- 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.