Migrating auxiliary removal for the transition zone longwall face - distance

摘要

A walking mine support unit has a pair of adjacent supporting frames each having a multi-partite sole plate and a multi-partite roof shield. The sole plate and roof shield of each frame are connected only at their respective leading and trailing ends, by hydraulic rams which permit the roof shields to be raised and lowered relative to the sole plates, and by four-bar linkages which permit length-wise displacement of the roof shields parallel and relative to the sole plates. A multi-section overshield is located above each of the roof shields and connected thereto by adjustable supports. An arrangement is provided for advancing the unit in stepwise manner.