Conveyor devices, in particular for use in substrate treatment devices, and configurations of substrate treatment devices, in particular horizontal coating installations for the mass coating of plate-like substrates during the production of solar cells are provided. The conveyor device comprises a multiplicity of conveyor rollers, each mounted rotatably at both ends thereof. During operation of the conveyor device, at least one conveyor roller is displaceable axially, i.e. parallel to the axis of rotation thereof.