Telescopic elevator devices in particular for dollies

摘要

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.