Digital private branch exchange and method of manufacturing same
CA 1332459 C · Owner: Kabushiki Kaisha Toshiba · Inventors: Ikemori, Kimio
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A digital private branch exchange including a digital trunk which in turn includes a connection request reject channel and a method of controlling the exchange. If there is a connection request to the reject channel an, audible tone signal indicative of the rejection of the connection request is read from a memory provided in the digital trunk, and sent to the extension telephone set which has made the connection request.
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 October 11, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 11, 2011.
- 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.