Station controller for enhanced multi-line pick-up in centrex exchange telephone system
CA 2006335 C · Owner: Nynex Corporation · Inventors: Beierle, John David
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A telephone system employing a centrex exchange having multi-station pick-up groups wherein a station controller means is situated between the exchange and the centrex telephone stations and provides lamp control of the secondary stations of the pick-up groups, and wherein the centrex exchange provides control of the call transfer from the primary stations of the pick-up groups to the respective secondary stations.
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 21, 1989 and granted December 21, 1993. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 21, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 21, 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.