Tractor and semi-trailer combinations are usually coupled only by one position of the articulated point. Accordingly all the force acting on a tractor and a trailer relatively is to concentrate on this one point. This thing cannot be always considered as the best approach about stability and controllability of the articulated vehicle. So, we devised a new coupling mechanism to improve the stability and controllability of the tractor and semi-trailer combinations. In a word acting points of longitudinal and lateral force and of vertical force are divided with using the new coupling mechanism, and so, the stability and controllability of the articulated vehicle are improved. In this paper, we describe availability of the new coupling mechanism proved by experiments with a scale model and theoretical analysis with a mathematical model.