Patent ID: 7416188

Claim:
Vehicle comprising a chassis ( 1 ), at least two mutually separated wheels ( 3 ) arranged on a first side ( 2 ) of the chassis and two mutually separated wheels ( 5 ) on the opposite, second side of the chassis ( 4 ), the wheels being arranged to support the chassis when resting on the ground, with the wheels on the first side rotatable about axes substantially fixed in position in the vertical direction relative to the chassis and the wheels on the second side arranged on a frame part ( 6 ) pivotably arranged relative to the chassis about a substantially central longitudinal axis ( 8 ) running between the first and the second sides of the vehicle to create a stability area for the vehicle in the shape of a triangle in the horizontal plane, an arrangement ( 12 ) to determine the position of the vehicle's tipping point (T) in relation to the stability area and thereby the vehicle's stability, and means ( 17 ) for fixing the frame part relative to the chassis on the order of the arrangement to increase the vehicle's stability area to be defined by said wheels, wherein said arrangement ( 12 ) is structured and arranged to continuously determine the position of the vehicle's tipping point (T), when the vehicle's tipping point reaches a boundary area ( 19 ) of the stability triangle, the fixing means ( 17 ) are structured and arranged to gradually increase the resistance against a pivoting of the frame part relative to the chassis about said longitudinal axis on increasing distance of the tipping point from the triangle's centre to gradually increase the stability area, and when said tipping point reaches a pro-determined boundary, said fixing means ( 17 ) are structured and arranged to completely fix the frame part ( 6 ) relative to the chassis ( 1 ) and form a stability area defined by said wheels, and said wheels ( 5 ) mounted on the second side are mounted underneath said pivotally-arranged frame part ( 6 ).