Security systems for controlling passage between restricted and unrestricted areas
CA 1269440 C · Owner: Dicaire, Luc · Inventors: Dicaire, Luc; Leroux, John E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
There is provided a new and useful security system for controlling passage between a restricted and an unrestricted area comprising an electrically operated door locking device to be installed on a door between the restricted and the unrestricted areas; a receiving device to be installed on at least the unrestricted side of the door and adjacent the door which activates or deactivates the door locking device responsive to received ultrasonic waves; and a remote transmitting device for transmitting ultrasonic waves to the receiving device.
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 May 22, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 22, 2007.
- 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.