Articulated tractor-trailer having adjustable trailer length and a tippable platform

Tractor comprising a front frame which has a first pair of wheels, an engine and an operator's control cabin, and a rear frame which has a second pair of wheels, the front and rear frames being linked to each other by a hinge with a vertical pivot and by a steering power means for the steering of the tractor, wherein the rear frame consists of an interior body and an exterior body which are telescopically movable relative to each other using a sliding power means, the hinge being attached to the interior body while the second pair of wheels are mounted to the exterior body, the exterior body being provided with a tipping device and a tipping power means for tipping a platform body placed on the tipping device, the platform body being connected to the interior body by flexible pulling means passing over a first guide mounted on the interior body and a second guide mounted on the exterior body, wherein said sliding power means is a hydraulic cylinder and piston unit attached to the interior body and the exterior body, said cylinder and piston unit attached to the exterior body at a fulcrum, said second guide being a roller mounted near said fulcrum.