US Patent 7377531 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, and a lower, laterally-outward extended position that facilitates easy entrance into and exit from the vehicle. A plurality of longitudinally spaced, selectively-actuated links connect the running board to the frame. A selectively-operable driving mechanism concertedly actuates each of the links 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.