Patent ID: 8813653

Claim:
A rail guided vehicle system comprising: a rail guided vehicle provided with at least a lateral pair of adjustable rollers in height that may be raised or lowered, and a changer mechanism that changes positions of the right and left adjustable rollers in height so as to bring both the right and left adjustable rollers in height to an intermediate position or bring one of the adjustable rollers in height to an advanced position and the other to a retracted position; travelling rails, for the rail guided vehicle, provided with a lateral pair of guide parts, said guide parts comprising short guide parts having a relatively short vertical protruding length, intermediate guide parts having an intermediate vertical protruding length, and long guide parts having a relatively long vertical protruding length; wherein in the intermediate position, the adjustable rollers in height are guided by the long guide parts over an entire roller width along a height direction, partially guided by the intermediate guide parts along the height direction, and not guided by the short guide parts, wherein in the advanced position, the adjustable rollers in height are guided by the long guide parts, the intermediate guide parts, and the short guide parts, wherein in the retracted position, the adjustable rollers in height are not guided by the intermediate guide parts or the short guide parts and are guided only by the long guide parts; a branching/merging part connecting one travelling rail having a branching side, and another travelling rail having a straight-travelling side, and having a branching/merging route, a branching part, and a merging part; wherein said one travelling rail branches into the branching side and the branching/merging route in the branching part, wherein the branching/merging route merges with the straight-travelling side in the merging part; wherein the guide part closer to the branching/merging route in the branching part and the guide part closer to the branching/merging route in the merging part are the intermediate guide parts, wherein both the right and left guide parts in the branching/merging route are the long guide parts, wherein at least the guide parts on sides opposite the branching/merging route are the short guide parts on the branching side and the straight-travelling side; and a controller controlling the changer mechanism such that when the rail guided vehicle travels on the one travelling rail toward the branching side and when the rail guided vehicle travels straight on the other travelling rail, the height adjustable roller on the side opposite the branching/merging route takes the advanced position and the height adjustable roller on the branching/merging route takes the retracted position, and when the rail guided vehicle travels on the branching/merging route, the right and left adjustable rollers in height take the intermediate position.