A guide for mineral winning machines is composed of assemblies secured to the mineral face side of a conveyor. The assemblies have angle plates secured to the side walls of the conveyor pans and structures, integral or otherwise, which provide spacers at least partly defining elongate upper and lower passages for accomodating a drive chain. Covers are detachably and pivotably mounted to the structures to close off the upper passage. The covers are provided with substantial flat upper surfaces which serves to support and guide a machine. An upper guide rail formed by ribs at the edges of the upper surfaces and a lower guide rail formed by webs or web plates on the structures serve to locate with guide means of a plough supported on the inclined walls of the angle plates and driven by the drive chain. Where the flat support surfaces are not needed, or otherwise in case of need, the covers can be removed or replaced by covers of different design. In the latter case the upper guide rail can still be established by the different covers.