Wheelchair lift

A wheelchair lift for a vehicle having an undercarriage, an entrance and a floor above said undercarriage with a cut-out adjacent said entrance and of sufficient dimensions to allow the passage of a wheelchair comprising:

• a. a platform of predetermined thickness adapted to fit within the cut-out in the floor of said vehicle of sufficient dimensions to accommodate a wheelchair, for traversing between said floor and ground level;
• b. a shaft within the side of s aid vehicle having left and right sides adjacent the left and right edges respectively of the entrance of said vehicle and having an open side at said entrance and a back side opposite the entrance of said vehicle, said shaft being disposed between the cut-out in the floor of said vehicle and the undercarriage of said vehicle and of sufficient width and depth to allow the passage of said platform therein;
• c. left and right pairs of cover panel tracks adjacent the vertical edges of each of said left and right sides of said shaft;
• d. left and right cover panels adjacent and parallel to each of the left and right sides of said shaft, the vertical edges of said cover panels adapted to slide up and down within said corresponding pairs of cover panel tracks, each having a plurality of pins mounted at predetermined locations perpendicularly to the side of each of said cover panels facing the interior of said shaft;
• e. an undercarriage cover of sufficient dimensions to close-off the lower open end of said shaft attached between the lower edges of said left and right cover panels, for traversing between the undercarriage of said vehicle and ground level;
• f. left and right pairs of pulley panel tracks mounted on each of said left and right cover panels respectively, adjacent the vertical edges of said cover panels on the side of each of said cover panels facing the interior of said shaft;
• g. left and right pulley panels adjacent and parallel to each of said left and right cover panels, adapted to slide up and down within said left and right pairs of pulley panel tracks respectively, each having a plurality of pin contact placed at predetermined locations below said pins on each of said corresponding cover panels being adapted to contact the pins on said cover panels and raise or lower said cover panels and said undercarriage cover at predetermined points during the lowering or raising of said pulley panels, causing said undercarriage cover to alternately close-off or open the lower end of said shaft;
• h. left and right pairs of platform pulleys each of a predetermined effective radius and each having a rotational axis, mounted to each of said left and right pulley panels respectively and adjacent the top edges thereof, such that the rotational axes of said pulleys are perpendicular to the side of each said pulley panel facing the interior of said shaft, the rotational axes of said pulleys being adapted to traverse between an upper level located a distance greater than the effective radius of each said pulley below the floor of said vehicle, and the midpoint between said upper level and ground level;
• i. left and right pairs of platform tracks mounted vertically below the floor of said vehicle adjacent each of the left and right sides of said shaft;
• j. left and right pairs of platform chains each of a predetermined length passing over said left and right pairs platform pulleys respectively, each said chain being attached at one end to a fixed point on said vehicle at or below the midpoint between said upper level and ground level, and each attached at its other end to said platform;
• k. left and right pairs of platform guides attached to the left and right edges respectively of said platform, adapted to slide up and down on said left and right pairs of platform tracks respectively;
• l. left and right side pulleys each having a rotational axis, mounted below the floor of said vehicle adjacent the left and right sides respectively of said shaft, the axes of rotation of each said side pulley being parallel to the left and right sides respectively of said shaft, and being parallel to said floor;
• m. a hydraulic cylinder having a piston end and a cylinder end with a base at the end opposite the piston end, mounted beneath the floor of said vehicle perpendicularly to and opposite the back side of said shaft;
• n. a cylinder bracket attached to the tip of said piston end of said hydraulic cylinder having left and right cylinder pulleys each having a rotational axis mounted therein such that their rotational axes are perpendicular to said floor;
• o. a plurality of drive chain pulleys each having a rotational axis, mounted both to the left and right of said hydraulic cylinder at predetermined locations beneath the floor of said vehicle such that their rotational axes are perpendicular to said floor;
• p. left and right drive chains each attached at one end to said left and right pulley panels respectively, passing over said left and right side pulleys respectively, passing over said left and right drive chain pulleys respectively, passing over the left and right cylinder pulleys respectively, and each attached at its other end to left and right cylinder attachments respectively at the base of said hydraulic cylinder;
• and
• q. means for supplying hydraulic fluid to and actuating said hydraulic cylinder, causing said drive chains to raise or lower said pulley panels and said platform.