Self-adjusting telephone status detection and indication
CA 2108936 A1 · Owner: Te Electronics Inc. · Inventors: Parkerson, Walter E.; Forrester, Roger D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a telephone system, a method for detecting and indicating status of a telephone line, comprising the steps of: (a) selecting a phone line whose status is to be detected; (b) measuring the voltage level associated with the selected line; (c) comparing the voltage level measured with a previously measured voltage level to determined whether the voltage measured is equal to less than or more than the previously measured voltage level; and, (d) dependent on the results of the previous step, updating the indication of the status of the line whose status is to be determined.
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 October 21, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 21, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 21, 2015.
- 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.