Impact attenuating device for vehicle

The invention relates to an impact-attenuating device ( 1 ) connected to a vehicle ( 2 ), especially a lorry. The impact attenuator ( 1 ) comprises a front part ( 3 ), an attenuating part ( 4 ), a rear part ( 5 ), and an extension device ( 6 ). The front part ( 3 ) is connected to the vehicle ( 2 ) in order to, during a collision into the impact attenuator; transfer the forces from the attenuator to the vehicle. The front part ( 3 ) comprises two wheels ( 31 ), with a pivot function, suspension ( 32 ), and a traffic routing board ( 9 ). Between the front part ( 2 ) and the attenuating part ( 4 ) is the extension device ( 6 ) arranged. The extension device ( 6 ) has a transport position and an operation position. In the transport position the extension device ( 6 ) is in its extended position and the attenuating device ( 4 ) is moved away from the front part ( 3 ). The extension device ( 6 ) is connected to the attenuating device ( 4 ) via a horizontal joint ( 63 ). In the transport position the extension device is hanging freely between the rear part ( 5 ) and the front part ( 3 ).