Key telephone system paging lockout circuit
CA 1106988 A · Owner: International Standard Electric Corporation · Inventors: Saxon, Bruce R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure, The telephone system includes N line circuits where N, is equal to an integer greater than one. Each of the line circuits includes a first relay controlled circuit to lockout (N-1) of the line circuits from a paging amplifier if any of the (N-1) of the line circuits attempts to initiate a paging operation a fraction of a second after one of the N line circuits has initiated a paging operation. A second relay controlled circuit applies a busy tone to a telephone subset associated with each of the (N-1) of the line circuits attempting to initiate a paging operation after the one of the N line circuits has initiated a paging operation.
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 August 11, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 11, 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.