System for transmitting alarm information over telephone lines
CA 1096520 A · Owner: Post Office (The) · Inventors: Barton, Michael J.; Howard, Michael H.; Chamberlain, Ian C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An alarm system for transmitting alarm information via telephone lines has a plurality of alarm transmitters which are located at subscribers' premises and are adapted to transmit signals indicative of the state of alarms associated with the transmitters along telephone lines to associated receivers. The receivers are located at one or more local exchanges and the receivers at a local exchange are all connected to a local processor. The or each local processor is connected to a central processor which can direct alarm information to one of a number of terminal stations. the local processors continuously scan the outputs of the receivers. When a local processor detects a signal indicative of …
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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 February 24, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 24, 1998.
- 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.