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Priority claimed from DE19681583799external-prioritypatent/DE1583799B2/de
Application filedfiledCritical
Publication of BE727234ApublicationCriticalpatent/BE727234A/xx
E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
E21D23/00—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor
E21D23/08—Advancing mechanisms
E21D23/081—Advancing mechanisms forming parts of the roof supports
E21D23/085—Advancing mechanisms forming parts of the roof supports acting on a conveyor or a guide for the mining machine
