Convertible rail-highway vehicle support system

A convertible rail-highway vehicle, comprising:

• a semi-trailer including an elongated beam extending centrally, longitudinally of said trailer;
• first truck means adjacent the rear of said trailer pivotally connected to said beam for movement about a first vertical axis, said truck means including
• (a) at least a pair of spaced and parallel axle means for carrying at opposite ends of each thereof a pair of flanged wheel means and a pair of highway wheel means, the axes of rotation of said highway wheel means being radially offset from the axes of rotation of said flanged wheel means;
• (b) a laterally extending support member pivotally connected to said elongated beam, said support member having a pivot means thereon;
• and
• (c) a pair of elongated and parallel bar means supported on said laterally extending support member and on opposite lateral sides of said beam, said pivot means pivotally supporting each of said bar means on said laterally extending support member for movement about an axis extending transversely of the longitudinal axis of said trailer and universal joint coupling means on each of said bar means coupled to each of said axle means for (1) maintaining the parallel spacing between said axle means, (2) facilitating the movement of said bar means about said pivot means and for (3) supporting each of said axle means for rotation about the longitudinal axis thereof;
• releaseable connecting means connecting said trailer selectively to a highway tractor and to a second truck means adjacent the front end of said trailer for pivotal movement also about a second vertical axis;
• and
• drive means on said first truck means operatively connected to each of said axle means for effecting a rotary drive of said axle means and a movement of said flanged wheels and said highway wheel means on each of said axle means to an exchanged relation relative to the ground.