Abstract: An anti-slip device is operated automatically by a driver from his cab by a hydraulic or manual system. Detachable blades each pivotable around a shaft are disposed on each drive wheel. In order to use the blades they must emerge and project from the peripheral part of the wheel, thus penetrating into the ground. The blades are successively actuated by a roller which rests against a control portion of the blade. The roller is mounted on a lever arm which is moved by a hydraulic jack or by a manual lever system. The blades penetrate the ground and thus prevent the wheel from slipping. In the operating position, the active portion of the blade transmits the penetrating force to the pivot shaft and a stop, i.e. not to the control portion.