Trailer and trailer unloading system

Abstract

A trailer and method for unloading onto the ground or like surface using an unarticulated frame and no power sources other than the tractor or prime mover. The frame supports three rows of overlapping transverse rollers and has a tail-end roller substantially across its width. A wheeled carriage is mounted to the underside of the frame, so that it can be longitudinally shifted. When mounted on a conventional 'fifth wheel' connection to the tractor, shifting of the carriage forward lowers the tail end of the frame which pivots downward about the connection to the trailer. Shifting the carriage back raises the tail. A pair of ground rollers is provided at the tail of the trailer which contacts the ground as it is lowered. A load may be placed onto the ground by unlocking the carriage, applying the brakes to the wheels of the carriage and backing up the tractor-trailer. When the trailer end is lowered so that the ground rollers are on the ground, the trailer is stopped, the load is unstrapped, and the tractor trailer driven forward, out from under the load which is thus placed on the ground. Thereafter, by applying the carriage brakes again while driving the rig forward, the frame is returned to its raised tail position, the carriage relocked, and the unloaded rig can be driven on the road.