Belt conveyor (1) having a centring assembly (2), comprising a supporting bracket (3) and two roller holders (4 A-B) each having at least a conical roller (40 A-B) that is rotatably suspended in the respective roller holder, wherein the centring assembly (2) has a supporting bracket direction (U) that rotates along with the centring assembly (2) which direction (U) in an inactive position is the same as the transport direction (T). Each of the roller holders (4A-B) comprises at least one curved arm (46A-B) and the supporting bracket (3) comprises at least two curved slides (35A-D) that are placed in the supporting bracket (3) so as to be mirror- symmetrical with respect to a plane of symmetry of the centring assembly (2), wherein the curved arms (46A-B) are placed in the curved slides (35A-D) wherein the roller holders are connected to the supporting bracket (3) so as to be adjustable at an angle.