Abstract: A towable wheeled undercarriage for carrying and supporting heavy loads and more particularly a carriage for supporting a crane of heavy duty or high capacity type. The carriage or carrier has a plurality of front and rear wheeled units independently mounted on a structural frame extending longitudinally of the vehicle and with at least the front wheels thereof being steerable. A gooseneck extends forwardly from the carrier and a coupling means on the forward end thereof connects to the fifth wheel of a tractor or towing vehicle. The coupling includes cushion means to support variable loads imposed by the fifth wheel on the gooseneck during towing and a linkage assembly is provided which is controlled by the fifth wheel to steer the front steerable wheels.

Abstract: A towed vehicle includes a frame, front and rear ground-engaged wheel assemblies mounted along said frame in such a manner that the center of gravity of said vehicle is situated between said front and rear wheel assemblies, and a gooseneck secured to said frame and projecting therefrom. A fluid pressure suspension cylinder is secured to the gooseneck adjacent the free outer end thereof and has a plunger reciprocally mounted therein and projecting downwardly therefrom. A plate with a king pin is secured to the plunger for coupling with the saddle of a fifth wheel on a towing vehicle. The plunger in the cylinder acts in conjunction with a compressible medium, to cushion loads between said gooseneck and towing vehicle. The fifth wheel by way of linkages from a collar rotatably mounted on the cylinder, steer steerable wheels on the towed vehicle.