20100225137 | TRANSPORT TRAILER LIFTGATE APPARATUS AND METHOD OF OPERATING THE SAME - A liftgate apparatus may include a plurality of vertical tracks attached to a rear of a trailer, each of the plurality of vertical tracks including a vertical roller chain. Tops of the plurality of vertical tracks intersect horizontal hollow structural tubes which include hydraulic cylinders. The apparatus may also include at least one bar attached to a bottom of each vertical roller chain and attached to sets of rolling wheels configured to move the at least one bar vertically inside the plurality of vertical tracks and a plurality of hinges attached to a lower end of the at least one bar and attached to a base of a liftgate, wherein the vertical roller chain lifts the at least one bar and the liftgate at hinged points. The apparatus may also include a plurality of types of link chains, wherein a first type of the link chains supports the liftgate in a closed position and the first type is affixed to the top of the at least one bar and to the liftgate, and wherein a second type of the link chains is affixed to the top of the vertical roller chain and to mid sections of the liftgate. The apparatus may further include a plurality of sprockets connected via a shaft, wherein the vertical roller chain travels over at least one of plurality of sprockets and connects the hydraulic cylinders to the least one bar, thereby moving the at least one bar and the attached liftgate in a synchronized manner. | 09-09-2010 |