Abstract: A rack assembly for a mine winning machine drive arrangement is described. The rack assembly is associated with a longwall conveyor along which a mine winning machine is movable by the drive arrangement. The rack assembly is constituted by a plurality of rack sections and a plurality of support members for connecting the rack sections to the longwall conveyor. Each of the rack sections has a respective downwardly-extending coupling pin at each end thereof, each of the coupling pins extending through an elongate slot in a respective support member with a predetermined amount of play. Each of the coupling pins is provided with a retaining member for preventing that coupling pin from moving out of the associated slot. The rack assembly is such that the rack sections of each adjacent pair of rack sections are relatively pivotable in vertical and horizontal directions, and are relatively movable to a predetermined extent in the longitudinal direction of the rack assembly.

Abstract: A mine working machine employs a main drive transmission with a vertical driven output shaft carrying a gearwheel which can be interchanged with a chain wheel for effecting a chain drive. For a chainless drive, an auxiliary transmission with a housing covering the gearwheel is attached to the machine body or the housing of the main drive transmission. The auxiliary transmission employs rotatable upstanding shafts located at the goaf side of the machine and in the auxiliary housing. The shafts carry gearwheels at their upper ends meshing with the driven gear wheel and pinions at their lower ends meshing with a multi-part rack extending along the path of movement of the machine.