Control mechanism for the extension units in the longwall face of a mine

A longwall support control for controlling the movements of a plurality of longwall support units in the longwall of a mine, comprising:

• a central control system, and
• a separate mining shield control device locally and operationally associated to each longwall support unit, the mining shield control devices being connected via radio to a portable decentralized operating device for inputting control commands and for feeding back inspection data,
• wherein each mining shield control device comprises a multi-channel radio transceiver, such that the mining shield control device is in a simultaneous transmit and receive mode with the decentralized operating device for receiving control signals and for transmitting inspection data, and wherein the mining shield control device is programmed in such a manner that control signals that are received via radio, can be converted into functions of the longwall support unit when the control signal stores a code word that is associated with the called up mining shield control device, and
• wherein the mining shield control devices are interconnected and also connected to the central control system via at least one bus line for transferring input data to all mining shield control devices, and
• wherein a mining shield control device closest to the decentralized operating device receives the strongest radio signal from the decentralized operating device and is able to retransmit the received signal via the at least one bus line to the other mining shield control devices, while also permitting direct back and forth radio contact between the operating device and a selected mining shield control device.