Abstract: A converter dolly for connecting a second trailer in tandem to a first trailer is provided. The converter dolly comprises a base, a connector frame pivotally connected to the base for horizontal movement about a substantially vertical axis, a dolly locking structure, and a plurality of ground engaging wheels carried by the base. The connector frame includes a hitch for pivotally connecting the connector frame to the forward wheeled vehicle for substantially horizontal movement about a substantially vertical axis, and a fifth wheel assembly fixed on the connector frame to pivotally connect the connector frame to the rear wheeled vehicle for substantially horizontal movement about a substantially vertical axis. The fifth wheel assembly includes a fifth wheel locking having an unengaged position and an engaged position for preventing rotational movement between the connector frame and the rear wheeled vehicle in its engaged position.

Abstract: A converter dolly for interconnecting and facilitating backing up of a tandem trailer assembly pulled by a tractor is disclosed. The converter dolly is coupled to the rear of a first trailer for pivotable movement relative thereto about a substantially vertical axis. The converter dolly includes a wheeled frame. A fifth wheel is fixed on the wheeled frame and has a front end defining opposing front corner portions. The wheeled frame includes a coupling assembly for coupling the wheeled frame to a second trailer for pivotable movement about a substantially vertical axis. A locking mechanism cooperates with the fifth wheel and includes a spaced pin housing secured at each front corner portion of the fifth wheel so that when the fifth wheel pivots up or down, the housings move as units with the fifth wheel. A pin is positioned in each housing and movable therein from a retracted to an extended position.