Multy-party telephone system
CA 1085075 A · Owner: Telefonaktiebolaget Lm Ericsson · Inventors: Broger, Lars; Magnusson, Sten
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A multy-party telephone system is provided for connecting, with a limited number of wires telephone sets, included in the system to at least one external line and to, each other respectively. The system contains arrangements for obtaining an exchange of information between the telephone sets and a control unit included in a central unit of the system. All signalling between the telephone sets and the central unit is carried out digitally. A first line system is provided for signalling by means of digital code words between the telephone sets and the central unit. This includes a first pair of wires for signalling in a first direction and a second pair of wires for signalling in a second …
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
- Granted September 2, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 2, 1997.
- 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.