US Patent 7318596 Retractable running board

A retractable running board assembly is mounted to the frame of a vehicle. The running board is selectively extendable between a retracted position, which is close to the vehicle's frame, a lower, laterally-outward extended position that facilitates easy entrance into and exit from the vehicle and a roof-access position, higher and outward from the entrance position. A selectively-operable driving mechanism actuates a link to extend and retract the running board. When the driving mechanism is not operated, each link resists actuation and holds the running board in a fixed position relative to the frame.