Expired Canadian patentCanada
Telecommunication systems
CA 1091831 A · Owner: Stc Plc · Inventors: Weir, Donald A.
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure A digital TDM/PCM telephone system is described which uses a simple module which is capable of functioning as a multiplexer or as a concentrator and is locatable at the telephone exchange, at a distribution point or at a subscriber terminal.
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 December 16, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 16, 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.
FiledFebruary 10, 1977
GrantedDecember 16, 1980
Term endedDecember 16, 1997
Patent numberCA 1091831 A
Classification (IPC)H04J3/00 +1 more
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.