Radio communication systems for underground mines
US4777652A · kind A · utility
74Cited by
8References
14Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 27, 1982 |
| Grant date | Oct 11, 1988 |
| Priority date | — |
| Expiry date | Jul 27, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B5/22
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A radio communications system operational within the medium frequency range for underground mine communications, coupling MF carrier signals into existing conductive channels extending to within the mine and devices within the mine and coupled to the conductive channel for receiving the MF carrier signals and communicating with portable and mobile transceivers operational within the MF frequency range and in the common seam mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.