Elimination of false requests for telephone operator assistance
CA 1290432 C · Owner: American Telephone And Telegraph Company · Inventors: Daudelin, Abraham Nelson
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract, A problem has been encountered in directory assistance and intercept systems which provide automatic announcement facilities to announce a directory number or line status to a customer and which permit the customer to be subsequently connected to an operator if the announcement is unsatisfactory. In such systems if the, customer disconnects and immediately attempts to place another call, such a situation may be interpreted by the local switching system serving the customer as a "flash"; if the customer is provided with three-way calling then the connection to the directory assistance or intercept system is put into a hold state while the customer dials a new number. In the …
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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 October 8, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 8, 2008.
- 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.