Multi-directional railway vehicle

Claim 1

A carrier device moveble along pathways each defined by a stationary central rail and flanking side rails, which pathways include intersections where the rails of one pathway meet those of another at an angle exemplified by a right angle, said carrier device comprising: a truck frame; a roller means powered to rotate about a generally horizontal axis; support means on the truck frame for mounting the roller means below the truck frame, the support means mounting the roller means for pivotal movement about a generally vertical axis; direction changing means on the truck frame for actuating the support means to pivot the roller means to a selected angular extent through a range of at least 90* ; guide wheel means rotatably disposed on the truck frame for rolling engagement with the side rails; and truck frame locking means including a central rail engaging fork means and means on the truck frame for advancing the fork means into engagement with the central rail and for retracting the fork means from such engagement, so that when it is desired to pivot the roller means at an intersection of pathways, the fork means may be advanced into engagement with the central rail if it is also desired that the truck frame not pivot when the roller means pivots but maintain the same absolute spatial orientation.