The carriage has two supports (58) carried by a pivoting frame (34) that is mounted on a chassis (10) to pivot about a horizontal pivot axis (42). Each support is connected to the pivoting frame by a joint (62) with a joint axis (64) parallel to the pivot axis and guided on a guide path (70) that is secured on the chassis. Each case set is vertically apart from the joint such that a line i.e. dot-dash line (72), runs through the joint axis and a roller axis (69) perpendicular to the supports and remains vertical on adjustment of the pivoting frame.