Abstract: A rail-supported carriage, adapted to be moved along a pair of rails spaced from one another at a predetermined distance includes at least three wheel assemblies, each including a frame; at least one wheel assembly is adapted to travel on one rail, and the remaining wheel assemblies are adapted to travel on the oppositely disposed rail. A connecting mechanism connects oppositely disposed wheel assemblies, and includes a compensating arrangement mounted on each wheel assembly for compensating any variation of distance between oppositely disposed wheel assemblies due to any curvature in the rails, each compensating arrangement includes a platform and a pin passing through the platform, and wherein the platform is movable with respect to the frame.

Abstract: The invention relates to a telescopic elevator device for dollies comprising in combination a wheel-mounted base member, a first extension member telescopically slidable on the base member, a second extension member telescopically mounted within the first extension member and apparatus for controlling the contemporaneous sliding of the extension members with respect to the base with a different speed so that the second extension member has a sliding speed which is the double of the first one.

Abstract: Dolly with articulated and steerable wheels, having steering angle compensation on the driving wheels, for particular use with cinema and television cameras.