Staff-location and signalling system for use in mines

A system for producing voice and signal connections in mines, the system comprising:

• an exchange;
• at least one base station in the mine area which base station is adapted to be in voice communication with the exchange and which has a transmitting and receiving device and associated antenna means and can be selectively coupled via secondary wave-guides to radio telephone sets in the mine area in order to produce radio telephone traffic;
• and
• a plurality of first signal receivers adapted to carried respectively with a miner's lamp by miners in the mine area and adapted to respond to coded radio signals transmitted by a base station via secondary wave-guides through the mine area, each of the first signal receivers having a respective switching device adapted to open and close a working-current circuit connecting the associated miner's lamp to a working-current source, the miner's lamp being switchable on and off in accordance with the said coded radio signals to give staff-location or warning signals.

A staff-location and signalling system in combination with a voice and signalling system for mines, the combination comprising:

• an exchange;
• at least one base station in voice communication with the exchange and located in the mine area and comprising a transmitting and receiving device with associated antenna means and adapted to be selectively coupled via at least one secondary wave guide to at least one radio telephone set in the mine area in order to produce radio telephone traffic:
• at least one relay station adapted to amplify radio signals transmitted via the secondary wave guide and located at preset distances from one another and from the said at least one base station in the mine area;
• a plurality of first signal receivers, each adapted to be carried together with a respective miner's lamp by miners in the mine area and each adapted to respond to coded radio signals transmitted by a said base station via the secondary wave guide in the mine area to be received by an antenna of a said first signal radio receiver, the signal receivers each having a respective switching device coupled to the radio receiver and adapted to open and close a working-current circuit connecting the associated miner's lamp to a working-current source;
• and
• at least one signal receiver associated with at least one respective group of lamps in a general mine lighting system and adapted to respond to the coded radio signals, the second signal transmitter having a signal input and a signal output and being adapted to receive signals transmitted from a said base station via the signal input, and further comprising a switching device coupled to the said signal output and adapted to open and close the supply-current circuit of the said at least one group of lamps in accordance with the coded radio signals,
• as a result of which the miner's lamps actuated by the first signal receivers and also the lamps in the general lighting system actuated by the second signal receivers can be switched on and off in accordance with the coded radio signals transmitted by the base station, so as to deliver staff-location and warning signals.