Radio communication systems for underground mines
CA 1207029 A · Owner: A.R.F. Products, Inc. · Inventors: Stolarczyk, Larry G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A communication system for underground mines which utilizes radio frequency waves at a first carrier frequency F1 within the range of 300 kHz to 3 MHz carried along a conductor which extends from the exterior of the mine into the mine and communicates with a plurality of mobile transceivers receiving on The frequency F1 and transmitting on a different frequency F2 at least 60 kHz different than F1. In addition, a repeater transmitting on frequency F1 and receiving on frequency F2 may be located in the mine to propagate the radiated signals, and carrier line signal repeaters receiving on frequency F2 and transmitting on frequency F1 may also be inductively coupled to the conductive line. 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 July 2, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 2, 2003.
- 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.