Disconnect circuit for use between telephone switching systems
CA 1233898 A · Owner: Gte Communication Systems Corporation · Inventors: Lembke, Robert W.; Wiebeld, Howard J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A disconnect circuit for use between two switching systems. An optical coupler monitors open and closed current loop conditions and provides signals representative thereof. Monostable multivibrators are operated in response to these signals to provide timing signals of predetermined durations. A relay circuit is controlled by these timing signals and it operates to disconnect the loop between the switching systems for a predetermined time.
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 March 8, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 8, 2005.
- 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.