Control system for a plurality of telephone sets
CA 1285670 C · Owner: Shimanuki, Masanobu · Inventors: Shimanuki, Masanobu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A control system for a plurality of telephone sets connected as branched to a central office line allows the extension galling, privacy function setting and hold releasing operations between the telephone sets. Each of the telephone sets in the branched connection comprises keys through which a control data corresponding to a desired control operation is inputted; a transmission circuit for sending to the central office line a control signal corresponding to the control data inputted by the keys, a reception circuit for receiving the control signal from the line, and a control circuit for performing a predetermined control operation on the basis of the control signal received by the …
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 July 2, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 2, 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.