Abstract: A supporting frame of a conveyor, over the top side of which the upper section of an endless conveyor belt is trained, comprises two identical symmetrically arranged angle sections. The upper legs of the angle sections are firmly connected to each other by an intermediate plate of any width. The lateral legs of the angular sections support at each end of the frame a pair of journal pins on which end sleeves are mounted for rotation. The two identical end sleeves are fimly connected to each other through a roller sleeve having a length corresponding to the spacing of the sleeves. By choosing the connecting members which are simple to adapt, namely the intermediate plate and the roller tubes, series manufactured stock elements, namely the longitudinal members of the frame and the end sleeves of the guide rollers, can be used for conveyors of various widths.