Abstract: A power supply device for a vehicle includes at least one contact head which can be connected to a vehicle and can be brought in contact with a docking station, wherein a contact head roll mechanism is rotatably connected to the at least one contact head and connected so as to be able to be brought in contact with the docking station, where the contact head roll mechanism includes at least two rolls or at least two rollers, via which a rolling contact can be established between the at least one contact head and the docking station, and where a first roll or a first roller is arranged on a first flank of the at least one contact head, and a second roll or a second roller is arranged on a second flank, located across the first flank, of the at least one contact head.