Call message delivery system and method
CA 2022262 C · Owner: American Telephone And Telegraph Company · Inventors: Chau, Nga V.; Brown, Percy B.; Karawas, Georg K.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract, A call delivery service (CDS) apparatus and method are disclosed which enable non-subscriber callers to a common carrier network to bill a voice message delivery to their billing code, and to check the delivery status of the message from the network during a subsequent call. Optionally at the caller's request, CDS can, deliver the message status to the caller at a predesignated station. In one embodiment the caller can optionally request a response from the message recipient or answering party at the called station.
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
- Filed July 30, 1990 and granted January 18, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 30, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 30, 2012.
- 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.