US Patent 9205883 Tank trailer having an adjustable kingpin assembly

A trailer having an adjustable kingpin assembly configured to adjust a ground clearance of the trailer. The adjustable kingpin assembly is configured to be detachably connected to a fifth wheel on a truck or tractor. The trailer includes a pivot frame having a kingpin pivotally coupled to a trailer. The pivot frame is configured to pivot between a first angular position and a second angular position to adjust a ground clearance of the trailer. The adjustable kingpin assembly also includes a rocker plate assembly pivotally coupled to the pivot frame and at least one bladder engaging the rocker plate assembly to rotate the pivot frame between the first angular position and the second angular position. The rocker plate assembly is configured to pivot to compensate for the pivoting of the pivot frame between the first and second angular positions.