Loop extender
CA 1069232 A · Owner: Cook Electric Company · Inventors: Glenn, Frederick J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure A loop extender is used in conjunction with a pair of telephone lines extending from a telephone central office to a subscriber location in order to insert a booster DC potential on the telephone lines in such a manner as to aid the flow of DC current produced on the telephone lines by a telephone central office battery. A control circuit has one input terminal coupled to one of the telephone lines and a reference terminal another input terminal coupled to the other telephone line and the reference terminal, and an output terminal coupled to a relay. Whenever the input terminals are supplied with a specified potential from the telephone lines an, output from the …
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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 January 1, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 1, 1997.
- 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.