Patent attributes
An air drag reduction apparatus includes left and right panels and top and bottom panels for mounting to the rear doors of a tractor trailer along the top, bottom and side edges thereof. Hinges are interposed between the panels and the doors so that the panels can pivot about the hinges between an extended drag-reducing position and a collapsed position generally adjacent the rear doors. Stop devices releasably secure the panels in the extended position, and biasing devices such as tensioning springs are operative to bias the panels outwardly and rearwardly to the extended position and are further operative to permit the panels to pivot between the extended position towards and to the collapsed position upon impact and contact from an external object occurring and then return to the extended position substantially immediately upon contact ceasing thereby significantly reducing the impact damage. The apparatus also includes a ramp and wheel arrangement to facilitate opening and collapsing of the panels. The apparatus of the invention also includes an outwardly extending panel protection member projecting from the lower corner of the panel in a position for being contacted by external objects during movement of the vehicle to thereby prevent direct contact between an external object and the panel and cause the panel to move toward its collapsed position.