US Patent 7658427 Impact absorbing tailgate

A vehicle tailgate includes a lower section carrying pivots adapted to be mounted to a vehicle bed; an upper section slidingly mounted to the lower section, so as to be able to move between an extended position and a retracted position relative to the lower section; and a biasing device which urges the upper section towards the extended position. The biasing device is selected so as to permit the upper section to move towards the retracted position when a predetermined force is applied.