Retractable cargo box assembly for a truck cargo bed

A retractable cargo box assembly for a cargo bed of a vehicle, the vehicle having a tailgate hingedly coupled to the cargo bed and moveable between an upright position and a downward position, the retractable cargo box assembly comprising:

• a) a cargo box including a base extending laterally between a first side and a second side, and extending longitudinally between a front end and a rear end;
• and
• b) a linear wheel assembly mounted to the base, the linear wheel assembly including a plurality of rollers aligned in a linear arrangement between the front end and the rear end of the base, the rollers being configured to rotatably support the cargo box on the cargo bed of the vehicle;
• wherein the cargo box is movable between a retracted position in which the cargo box is rotatably supported by the rollers on an upper surface of the cargo bed and an extended position in which the tailgate is in the downward position and the rollers are in direct contact with an upper surface of the tailgate to rotatably support the cargo box on the tailgate;
• and
• wherein the rollers that are in contact with the upper surface of the tailgate are unguided.